NEW ESSAYS
CONCERNING
HUMAN UNDERSTANDING
NEW ESSAYS
CONCERNING
HUMAN UNDERSTANDING
BY
GOTTFRIED \VILHELM LEIBNITZ
TOGETHER WITH
AN APPENDIX
CONSISTING OF SOME OF HIS SHORTER PIECES
TRANSLATED FROM THE ORIGINAL LATIN, FRENCH
AND GERMAN, WITH NOTES
BY
ALFRED GIDEON LANGLEY
A.M. (BROWN)
1 2x0 EDITION!
CHICAGO LONDON
THE OPEN COURT PUBLISHING COMPANY
11916
All rig Ills reserved
COPYRIGHT
THE OPEN COURT PUBLISHING CO.
Printed in the United States of America
&a mg JHotfjer antJ lister
SOMETIME GONK WHERE WE SHALL KNOW AS \VE ARE KNOWN
&nfc to mo father
STILL WHERE WE SEE AS IN A MIRROR OBSCURELY
IN DEEPEST LOVE AND' GRATITUDE
I DEDICATE THIS BOOK
CONTENTS
Translator's Preface . . xi
Gerhardt's Introduction to his edition of Leibnitz's Nouveaux
Kssais #
LEIBNITZ'S CRITIQUE OF LOCKE
On Locke's Essay on Human Understanding, 1696 . . . .13
Specimen of Thoughts upon the First Book of the Essay on Human
Understanding, 1698 20
Specimen of Thoughts upon the Second Book, 1698 .... 23
On Ooste's Translation of Locke's Essay concerning Human Under
standing ; from the " Monatliche Auszug," September, 1700,
pp. 611-636 .26
Addition thereto. "Monatliche Auszug," 1701, pp. 73-75 . 37
NEW ESSAYS ON THE UNDERSTANDING, BY THE AUTHOR OF THE
SYSTEM OF PRE-ESTABLISHED HARMONY
Preface . - .. 41 \-
Rook I. — Innate I<Je<is
<HA1>T?.K S
I. Are there innate principles in the mind of man ? . . 64
IJ. No innate practical principles ....... 85
III. Other considerations touching innate principles, both spec
ulative and practical ........ 100
Book IL— Ideas.
I. Which treats of ideas in general, and examines by the way
whether the mind of man always thinks .... 109
II. Simple ideas , 120 .
III. Of ideas which come to us by one sense only .... 121
IV. Of solidity . .122
V. Of simple ideas which come by different senses . . . 129
VI. Of simple ideas which come by reflection . 130
viii
CONTENTS
PACK
Of ideas which come by sensation and reflection . . 130
Other considerations upon simple ideas .... 130
Of perception . . 136
Of retention 142
Of discernment, or the faculty of distinguishing ideas . 143
Of complex ideas 147
Of simple modes, and first of those of space . . . 149
Of duration and its simple modes ... 155
Of duration and expansion considered together . . 158
Of number . . . .100
Of infinity 161
Of other simple modes ....... 164
Of the modes of thinking 164
Of modes of pleasure and pain ......
Of power and freedom . . . . . . . 174*-*'
Of mixed modes . . . . . . . . .221
Of our complex ideas of substances . . . . . 225
Of collective ideas of substances 235
Of relation 235
Of cause and effect and some other relations . . . 237
What identity or diversity is 238
Of some other relations, and especially of moral relations 258
Of clear and obscure, distinct and confused ideas . . 265
Of real and fantastical ideas 275
Of adequate and- inadequate ideas ..... 278
Of true and false ideas 281
Of the association of ideas . . . . . .281
Bool- HI. — Wonh.
I. Of words or language in general ..... 285
II. Of the signification of words 291
III. Of general terms 307
IV. Of the names of simple ideas . . 318
V. Of the names of mixed modes and relations . . . 325
VI. Of the names of substances ...... 330
VII. Of particles 364
VIII. Of abstract and concrete terms . . . . . . 368
IX. Of the imperfections of words .... . 369
X. Of the abuse of words . . . . . . .376
XI. Of the remedies which may be applied to the imperfec
tions and abuses just spoken of . . . . . 390
CONTENTS ix
Book IV.— Of Knowledge
CHAPTER
I'AGK
I. Of knowledge in general ......
. 397
II. Of the degrees of our knowledge ....
. 404
III. Of the extent of human knowledge ....
. 423
IV. Of the reality of our knowledge .....
. 444
V. Of truth in general .......
. 449
VI. Of universal propositions, their truth and certitude .
. 452
VII. Of propositions called maxims or axioms .
. 462
VIII. Of trifling propositions ......
. 490
IX. Of our knowledge of our existence
. 497
X. Of our knowledge of the existence of God .
. 449
XL Of our knowledge of the existence of other things
. 511
XII. Of the improvement of our knowledge
. 517
XIII. Other considerations concerning our knowledge , .
. 528
XIV. Of judgment ........
. 528
XV. Of probability .
. 529
XVI. Of the degrees of assent
. 532
XVII. Of reason
. 555
XVIII. Of faith and reason and their distinct limits
. 583
XIX. Of enthusiasm ........
. 596
XX. Of error
. 607
XXI. Of the division of the sciences
. 621
APPENDIX
I. Leibnitz to Jacob Thomasius. April 20-30, 1669.
. 631^
II. Fragment, (c. 1671)
. 651 v/
III. Demonstration against atoms taken from the contact
of
atoms. (October, 1690) 652
IV. Essay on Dynamics on the laws of motion, in which it is
shown that not the same quantity of motion is preserved,
but the same absolute force, or rather the same quantity
of moving action (V action motrice). (c. 1691) . . 657 *
V. Essay on Dynamics in defence of the wonderful laws of
nature in respect to the forces of bodies, disclosing their
mutual actions and referring them to their causes.
Parti. 1695 670 V
Ib. Part II. 1695 . . 684
VI. On the radical origin of things. 1697 692
VII. Appendix to a letter to Honoratus Fabri. 1702 . . . 699 V'
CONTENTS
PAGE
VIII. Letter of Leibnitz to Basnage de Beauval, editor of the
44 Histoire des Ouvrages des Savants," printed in that
journal, July, 1698, pp. 329 sq 706 I/
IX. Fragment of a letter to an unknown person. 1707 . . 712 v/
X. That the most perfect Being exists . . . . . 714 v/
XL What is idea 710 v^
XII. On the method of distinguishing real from imaginary phe- »/
nomena . . . . . . . • • .717
ADDITIONS .VND CORRECTIONS . . . . . . . .721
INDKX A. To the Critique of Locke ...... 777
INDEX B. To the Appendix ........ 823
INDKX C. To the Notes, Additions, and Corrections . . . 831
TRANSLATOR'S PREFACE
THE work herewith given to the public consists of a transla
tion of the entire fifth volume of Gerhardt's Die philosophischen
Schriften von G. W. Leibniz, sub-entitled " Leibniz und Locke,"
consisting of an Introduction by Gerhardt, several short pieces
on Locke's Essay and the New Essays on Human Under
standing; and of an Appendix containing a translation of
other short pieces of Leibnitz bearing on the subjects dis
cussed in the New Essays or referred to therein. The Intro
duction on The Philosophy of Leibnitz by the translator
suggested and urged by Professors Palmer and Royce of Har
vard University, and for some time contemplated, is deferred,
and reserved, if at all, for another time and occasion, owing
to the size of the present volume, as well as for other good
and sufficient reasons which it is not necessary here to
mention.
The translation of Leibnitz's Nouveaux Essais sur VEntende-
ment Humain was first suggested by the following sentence
of the late Professor George S. Morris, of the University of
Michigan, in a note to his Philosophy and Christianity, page
292: "It suggests no favorable comment on the philosophic
interest of the countrymen of Locke that the above-mentioned
reply of Leibnitz to Locke has never (so far as I can ascertain)
been translated into English." Four instalments, consisting
of Book I. and Book II., chapters 1-11 inclusive, were pub
lished in as many numbers of the "Journal of Speculative
Philosophy."1 Professor Morris very kindly sent me a care
ful criticism of about one-third of the first instalment, with
valuable suggestions regarding the further work of transla
tion. His corrections and suggestions received careful con-
1 Vol. 19, No. 3, July, 1885: Vol. 21, No. 3, July, 1887; Vol. 21, No. 4. Octo
ber, 1887 ; Vol. 22, No.' 2, April, 1888.
xii TRANSLATOR'S PREFACE
s [deration and were embodied in subsequent revisions of the
translation in preparing it for the present issue.
The portion of the New Essays thus published being
favorably received by professors and students of philosophy
in this country and in Europe, and being encouraged to go on
and translate the entire piece, the work begun in 1885 was
continued in leisure hours until in June, 1891, the translation
was completed. Revision, annotation, and the labor of get
ting it through the press have occupied the greater part of my
free time since then. The annotation, which was not a part
of the original plan, but which was found to be desirable, if
not even necessary, as the sheets began to appear in type, has
been the chief cause of the delay in the appearance of the
book, the labor involved therein proving far greater and una
voidably more protracted than was expected, the annotation
also, as is frequent in such cases, growing with the progress
of the book.
The text-basis of the translation is that of C. I. Gerhardt,
in his Die philosophischen Schriften von G. W. Leibniz, 7 vols.,
Berlin, 1875-1890, except for the Dynamical Pieces in the
Appendix, Nos. IV., V., the text-basis of which is C. I. Ger-
hardt's Leibnizens mathematische Schriften, Berlin and Halle,
1849-1863, and Appendix No. VII., "for which both these
editions are used; for Appendix No. IX., the text is that
given by Guhrauer, G. W. Freiherr v. Leibnitz. Eine Biographic,
Breslau, 1846. The other editions used in the comparison of
the text and the preparation of the notes are: J. E. Erd-
mann, Leibnitii Opera Philosophic®., Berlin, 1839-1840; M. A.
Jacques, (Euvres de Leibniz, Paris, 1842; P. Janet, (Euvres
PJnloxophiques de Leibniz, Paris, 1866; Dutens, Leibnitii Opera
Omtiia, Geneva, 1768; Foucher de Careil, Lettres et Opuscules
infants de Leibniz, Paris, 1854, Nouvelles Lettres et Opuscules
de Leibniz inedits, Paris, 1857, and (Euvres de Leibniz, Paris,
1859 sq., 2d ed., Paris, 1867 sq. R. E. Raspe, (Euvres Philoso-
phiques de feu Mr. Leibnitz, Amsterdam and Leipzig, 1765, was
received too late to be of service, but as his text is the original
printed text of the New Essays, and has been used by all sub
sequent editors, it is not probable that any important variation
of reading has been overlooked; and Raspe's text has no notes.
Besides these editions of Leibnitz's Works, the German trans-
TRANSLATOR'S PREFACE xiii
lations of the Theodicee and of the smaller philosophically
important works entitled Die kleineren pMlosophiscli wichtigeren
Schriften by J. H. von Kirchmann, in his Philosophische
Bibliothek, Berlin, 1879, and the English translation of his
important philosophical opuscules by Professor George M.
Duncan of Yale University, entitled The Philosophical Works
of Leibnitz, New Haven, 1890, have been consulted. From
the last-named work, so as to include in one book all of Leib
nitz's discussions of Locke, it was at first intended to reprint
in the Appendix all the pieces bearing upon the subject dis
cussed in the New Essays, or espesially referred to therein.
It finally seemed best to both Professor Duncan and myself
to change the plan and translate new material, rather than
duplicate that already translated, so that with the exception
of Appendix No. VI., Professor Duncan's translation of which
was either forgotten or unnoticed till after mine was in type,
nothing appears in both books save such portions of the New
Essays as he has included, and the piece entitled On Locke's
Essay on Human Understanding, 1696. This statement will
explain the references in certain notes, for example, page 101,
note 1, page 154, note 1 (cf. infra, pages 737 and 749 respec
tively), to certain pieces of Leibnitz in the Appendix, which
references are corrected in the Additions and Corrections by
being changed to the proper pages of Professor Duncan's
book.
Of great value in the revision of the translation, and of the
greatest service in the preparation of the notes, has been the
German translation of the Nouveaux Essais, with notes, by
Professor Carl Schaarschmidt of the University of Bonn.
His material has been freely used, either by direct translation
and quotation, or in substance, in the notes of the .present edi
tion, though always, so far as possible, only after verification
and further independent study. His notes, I regret to say,
contain many numerical errors, occasioned presumably by in
sufficient care and accuracy in proof-reading; otherwise they
are, for the most part, accurate. The fact that Professor
Schaarschmidt's book was not received till after a portion of
mine was in type accounts in part for the appearance of so
much of his note-material in the Additions and Corrections,
rather than in its proper place in the foot-notes to the text.
T RANSL ATO R'8 PR E F AC E
Professor A. C. Frazer's splendid edition of Locke's Essay,
Oxford, 1894, did not appear until after most of the New
Essays were in type; and P. Ooste, Essai philosophique con-
ceruant V Entendement humafn — par M. Locke, Amsterdam,
1742, 1 vol., 4to, 1774, 4 vols., 12mo, could not be obtained
until all the New Essays and most of the Appendix were in
type. Both of these works, therefore, could be used only in
the supplementary notes in the Additions and Corrections.
With regard to the text itself, particularly of the New Essays,
a few words may not be out of place. The variations are slight
and chiefly verbal, and scarcely ever essentially modify the
thought. They are ultimately due either to the manuscript of
Leibnitz — which Erdmann (Preface, p. xxii) says is " written
in such small characters often, and so full of corrections, that
it is very difficult to read it" ("tain parvis ssepe literis con-
scriptum et correctionibus adeo abundans ut perdifficile lectu ")
— or to certain changes made for the purpose of improving the
literary style of the author, and of thus making his work more
acceptable to his French readers. The chief difference between
the text as given by Gerhardt, who has compared his impres
sion "with the original, so far as it is still extant," and that
of the other editors consists in a transposition of the text in
Book I., chap. I., a transposition which is fully indicated in
the note at the point in the text of the translation where it
occurs, and which is, I suppose, due to Gerhardt's fidelity to
Leibnitz's original text. All the important textual variations
are listed in the notes.
Gerhardt's text, having been compared with the original,
seems the most trustworthy, and accordingly has been followed
in this translation, excepting in a few instances mentioned in
the notes, .where it is manifestly erroneous from inaccurate
proof-reading or other cause, and where the text of some other
editor seemed more consistent or correct. Gerhardt has intro
duced into his text the brackets, [ ], in which, " in the original,
Leibnitz has enclosed the words of Philalethes, who states the
views of Locke," "perhaps as an indication that they are not
his own ; " and I have introduced them into the translation
precisely as they stand in the text of Gerhardt, in order that
the translation may conform to and represent as perfectly as
possible Leibnitz's original text in its integrity. There seems
TRANSLATOR'S PREFACE xv
to be, however, little regularity or consistency in the employ
ment of these brackets, so far, at least, as I can discover upon
comparison with Locke's treatise.
Besides the editions and translations already named, the
various separate editions of single works of Leibnitz, as also
the various discussions of his philosophy, theology, etc., and
the monographs on different parts of the same, were occasion
ally consulted or referred to, so far as these were accessible
or could be procured. Among the monographs, especial men
tion should be made of Professor John Dewey's most excellent
Leibniz's New Essays concerning the Human Understanding.
A Critical Exposition, 1888, in the series of German Philo
sophical Classics edited by Professor George S. Morris, and
published by S. C. Griggs & Co., Chicago; and of the earlier
monograph of G. Hartenstein, Locke's Lehre von der mensch-
lichen Erkenntniss in Vergleiclmng mit Leibniz's Kritik derselben,
Leipzig, 1861.
The translation has purposely been made close rather than
free, a philosophical treatise seeming properly to require a
closer adherence on the part of the translator to the author's
form of thought and expression than a history, novel, or poem.
Whatever view may be taken on this point, — and I frankly
admit that at least two views are possible and that each method
of translation has its advantages and its disadvantages, its
perils and its successes, — the form and style of the New Essays
make an elegant and forceful translation well-nigh impossible.
Such a translation would necessitate the entire re-writing of
Leibnitz's work, would, in fact, be a reproduction rather than
a translation, a task I have not attempted nor felt it incumbent
on me to attempt. My aim has been simply to represent as
faithfully and as accurately as possible, and in as good English
as its form and expression admitted, Leibnitz's exact thought.
The style of Leibnitz in the New Essays, especially in the
abbreviations or abstracts of Locke's Essay put into the mouth
of Philalethes, is often abrupt and obscure and sometimes
even ungrammatical (c/*, for example, Neiv Essays, Book III.,
chap. II., § 18, page 392, lines 6 and 7, and the note thereto,
infra, page 768 ad fin.). This condition of things is due partly
to the form of the work, but chiefly to the method of its com
position (c/. Gerhardt's introduction, infra, page 8, and notes,
TRANSLATOR'S PREFACE
and the letters of Leibnitz cited by Raspe in his Preface, page
12, note 6, and which lie says, "I found with the manuscript
of the New Essays," and "give as I found them"). A work so
written, in spite of more or less revision, could not possibly
be a finished treatise or a work of literary art like the Dia
logues of Plato, and the character of the work must of neces
sity be reflected in the translation.
The notes aim to give the desirable or necessary biographical
and bibliographical information regarding the persons and
books referred to in the course of the work, so far as such
information could be obtained; references to other pieces of
Leibnitz, and occasionally to other authors, where the same
topic is discussed; and explanations of a few terms thought
to be obscure and the explanations of which are not generally
known or easily accessible. The notes do not pretend to be a
commentary on the text. Except in a few cases, the reader
or student has purposely been left to gain his knowledge of
Leibnitz's views from Leibnitz himself. Extended com
mentary was impossible within the necessary limits of the
volume, and accordingly was not included in the plan. The
philosophical notes, therefore, confine themselves to a brief
statement of Leibnitz's views and to brief criticism or indica
tion of criticism. The aim Avas to bring Leibnitz's great work
within the reach of English students and to render it more
easily accessible, with such annotation, literary and other, as
would make it more acceptable to the student.
All material taken from other authors has, so far as pos
sible, been verified and made the subject of such independent
study as the case seemed to demand. All references to
authorities have been verified when possible, and very great
pains have been taken to secure perfect accuracy in all refer
ences. The citations have uniformly been taken and the
references made to the best editions, and usually to the latest,
when these editions were accessible. Occasionally other works
or editions are referred to because of their accessibility or for
other evident reasons. For the convenience of those possess
ing different editions of Leibnitz's works, as well as for those
who may have access to only one of them, reference is usually
made, especially in the earlier notes, to all of the editions.
Later this procedure seemed to encumber the notes with an
TRANSLATOR'S PREFACE
unnecessary amount of numerical reference, and it was for the
most part discontinued.
Attention is called to the Additions and Corrections as
containing matter of importance, most of which was not
obtained till after the portion of the book to which it refers
was already in type, and which, therefore, could not be
inserted in its proper place in the book, but had to be reserved
to the end.
The Indexes are intentionally full and complete and have
been made with great care by Rev. Eobert Kerr Eccles, M.D.
There is no adequate index to Leibnitz's works, and none
whatever exclusively devoted to the New Essays. The refer
ences thereto in the meagre index in Raspe's edition of the
Philosophical Works, not generally accessible, and in the
general index, full as it is, in Erdmann's edition, are by no
means sufficient. It is hoped that the Indexes here furnished
may prove adequate for the works of Leibnitz included in this
volume, and that thus a beginning at least of an adequate index
to Leibnitz's complete works shall have been made.
In Appendix No. IV., infra, page 663, and No. V., infra,
pages 674, 682, and 686, the numbering of the cuts is changed
from that of the original text to conform to their proper
numerical order in this book. The fact is here noted to pre
vent confusion in referring to the original.
I gratefully acknowledge my obligations and express my
thanks to all who have aided me in my long and arduous work.
Especially to President E. B. Andrews of Brown University,
for aid in the note on the term " quarto modo," page 455,
and for the verification of references; to Professor Albert G.
Harkness of Brown University, for aid in locating some of
the Latin quotations in the New Essays; to Professor J. F.
Jameson of Brown University, for the note, page 757, ex
plaining the term "Promoter," page 227; to Professor John
M. Manly of Brown University, for information and aid in
the notes to the New Essays, Book III., chap. 2, page 294,
notes 2, 3, page 295, notes 2, 3; to Professor E. B. Delabarre
of Brown University, for aid in the note to page 122, lines
1, 2, infra, pages 739-740; to Professor H. P. Manning of
Brown University, for aid in the note on the " perles " of
De Sluse, page 768; to Rev. R. H. Ferguson, for aid in the
TR ANSI.ATOU' S PR EFACE
same note, and in the revision of a portion of the Appendix;
to Mr. Frank E. Thompson, A.M., Head-master of the Rogers
High School, Newport, B. I., for aid in connection with a
part of the subject-matter of the Dynamical Pieces in the Ap
pendix; to Professor Benjamin O. True of Rochester Theo
logical Seminary, for information and verification of references
in connection with the notes to the New Essays, Book IV.,
chap. 1 9, page 599, note 2, 601, note 1, 602, note 1 ; to Pro
fessor F. A. March of Lafayette University, for the location
of the Latin poetical quotation on page 603 ; to Professor Carl
Schaarschmidt of Bonn University, for consulting books inac
cessible in this country, and for information kindly furnished
by letter, and for his cordial interest in my work, as well as
for the very valuable notes to his translation of the New
Essays, without which mine never would have been written
in their present form; to the various libraries whose resources
have in one way or another been placed at my disposal, among
which should be mentioned the Boston Public Library, the
Boston Athenaeum, the libraries of Andover Theological Semi
nary, Newton Theological Institution, Rochester Theological
Seminary, Brown University, Harvard University, Yale
University through Professor Duncan, the Library of the
Surgeon General's Office, Washington. D.C., and the Red
wood Library, Newport, R.I.; to the libraries particularly
of Newton Theological Institution, Brown University, and
Harvard University, for the long-continued loan of needed
books ; to Professor Charles R, Brown of Newton Theological
Institution for information and the verification of references;
to my friend and former pupil Mr. Alfred R. Wightman, of
the Morgan Park Academy of the University of Chicago, for
the verification of references and aid in the revision of a
portion of the Appendix; to Mr. Thomas J. Kiernan of the
Harvard University Library, for special favors in the consul
tation of the library, for the loan of books from the same,
and for information cordially furnished by mail; to Benjamin
Rand, Ph.D., of the Department of Philosophy at Harvard
University, for frequent consultation of authorities, verifica
tion of references and information furnished; to my friend
Mr. Richard Bliss, Librarian of the Redwood Library, with
out whose competent criticism and constant advice and aid,
TRANSLATOR'S PREFACE xix
added to his comprehensive and accurate knowledge in many
fields, and especially in bibliography, my notes would have
been far less full and accurate than, I trust, they now are;
and last but not least, to my wife for literary criticism in the
revision of the translation and notes, and aid in the laborious
task of proof-reading. Had I always accepted and adopted
her criticism and that of Mr. Bliss, my work would doubtless
rank higher as a piece of literature than is now possible.
My thanks are also due and most heartily tendered to
my publishers, Messrs. Macmillan & Co., for their uniform
courtesy and long-suffering patience in the repeated but un
avoidable delays which have characterized the appearance
of this book; and to J. 8. Gushing & Co., of the Norwood
Press, for the excellence of their work, and the pains they
have taken to secure the greatest possible accuracy in the
same, and for their uniform courtesy and long-suffering
patience amid the vexatious delays unavoidably incident to
the preparation of the notes and the correction of the proof.
In editing the work of a thinker and writer so comprehen
sive as Leibnitz, it is impossible to escape all errors of fact or
judgment. I have done the best I could in the circumstances
in which I have had to work, away from large libraries and
from the advice and criticism of fellow-students in the same
lines. Competent and truth-loving criticism, and the correc
tion of any and all real errors will be thankfully received.
With one sentence from Leibnitz's letter to Coste, June 1(5,
1707, as significant of his character and illustrative of his
spirit, more truth-loving than polemical, and as beautifully
expressing the essence of true criticism, I close this Preface :
'• Mon but a este plustost d'eclaircir les choses, que de refuter
les sentimens d'autruy," which, being interpreted, is: "My
purpose has been to throw light upon things rather than to
refute the opinions of another."
ALFKED G. LAXGLKY.
NEWPORT, R.I., April 11, 18%.
LEIBXIT/'S CRITIQUE OF LOCKE OX
HUMAN UNDERSTANDING
GEPHARDT'S INTRODUCTION TO HIS EDITION OF
LEIBNITZ'S NOUVEAUX ESSAIS
[From the (ret'incm]
IN the first philosophical treatise, Meditationes de Cognitfone,
Veritate, et Ideis,1 which Leibnitz published in the year 1684, he
had firmly laid the foundations of human knowledge ; he de
clared adequate and at the same time intuitive knowledge as
the most complete. At the end he adds : Quod ad controver-
siam attinet, utrum omnia videamus in DEO . . . an vero
proprias ideas habeamus, sciendum est, etsi omnia in DEO
videremus, necesse tamen esse ut habeamus et ideas proprias,
id est non quasi icunculas quasdam, sed aft'ectiones sive modifi-
cationes mentis nostne, respondentes ad id ipsum quod in DEO
perciperemus.: utique enim aliis atque aliis cogitationibus sub-
euntibus aliqua in mente nostra mutatio fit ; rerum vero actu
a nobis non cogitatarum Idese sunt in mente nostra, ut figura
Herculis in rudi marmore. The assumption of these ideas
slumbering in the mind, these innate ideas (nngebornen Ideen;
idees innees), Leibnitz regards as necessary in order to
understand the nature of the mind. (Habet anima in se
perceptiones et appetitus, usque natura ejus continetur, he
writes to Bierling, Hanoverse 12. Augusti 1711.2 Et ut
in corpore intelligimus OLVTITVTTMV, et figuram generatim, etsi
nesciamus, quse sint figurse corporum insensibilium : ita in
anima intelligimus perceptionem et appetitum, etsi non
cognoscamus distincte insensibilia ingredientia perceptionum
confusarum, quibus insensibilia corporum exprimuntur.)
He could therefore only prove the necessary truths, i.e.
1 C. I. Gerhardt: Die philosophischen Srhriften von G. W. Leibniz. Vol.
4, pp. 422-42(5. J. E. Erdmann: G. G. Leibnitii Opera Philosophica, pp. 78-
si. Translated by George M. Duncan, The Philosophical Works of Leibnitzt
pp. 27-:i2, New Haven : Tnttle, Morehouse, & Taylor, 1890. — TR.
^ The letter is found in Gerhardt's ed., Vol. 7, pp. 500-502. — TR.
LEIBNITZ'S CRITIQUE OF LOCKE
those which are known by demonstration, inasmuch as the
senses indeed teach what happens, but not what necessarily
happens. Such ideas innate to the mind are, according to
Leibnitz, the conceptions of substance, identity, the true and
the good.
The writing of the man who questioned and rejected these
fundamental principles of the system of Leibnitz could not
fail to lay claim to Leibnitz's entire attention. It was John
Locke (born, 1632, at Wrington, near Bristol ; died, 1704, at
Gates, in the county of Essex, in the house of Sir Francis
Masham, whose wife was a daughter of Cud worth), who in his
celebrated work (" An Essay concerning Human Understand
ing" ; in four books, London, 1690 *) sought to discover also the
origin, the certainty, and the extent of human knowledge, but
who denied the existence of innate ideas and principles, and
affirmed that the mind is originally like an unwritten tablet
(tabula rasa). In the first book of the work named, Locke
seeks to set forth the view that there are no innate ideas, and
therefore no innate principles and truths ; that the under
standing is by nature like an unwritten sheet of paper. The
second book contains the proof whence the understanding gets
its ideas. Since there are no innate concepts arid principles,
the origin of all ideas can be only in experience. Experience,
however, has a double sphere, that of external and of internal
perception : the first Locke calls Sensation; the second, Reflec
tion. Sensation is the perception of external objects mediated
through the senses ; reflection, the perception of the activities
of the soul in relation to the ideas presented through the senses.
Ideas are partly simple, partly complex. Simple ideas arise
through the single senses, remoter ideas through more senses,
as extension, form, motion, rest ; through reflection alone, for
1 Tliis work was already completed in the year 1(587 ; an abstract made by
Locke himself appeared in the following year, 1088, translated into French in
Leclerc's " Bibliotheqne universelle," T. VIII., pp. 49-142. The contents of
the work, after it was completely published in the year 1090, was communi
cated in much detail by Leelere in the " Biblioth. Univers.," T. XVII., p. :*99
*q. The new editions, which already in the shortest time followed each other
in quick succession in the years 1694, 1(!97, 1099, 1705, prove what a mighty
impression Locke's work made upon cultivated circles. 1700 appeared Coste's
French translation of Locke's work : it was enriched by Locke himself with
improvements and additions. Leibnitz; followed this French translation in
the composition of his Nouveaiix Essais.
ON HUMAN UNDERSTANDING
example, the idea of thought and will ; through union of sensa
tion and reflection, the ideas of power, existence, unity. The
complex ideas are of three kinds : modes, substances, relations.
The modes, i.e. the complex concepts, which contain nothing
existing for itself, are either pure (simple modes), as space, time,
or mixed (mixed modes), as thought, motion, power. By sub
stances Locke understands those combinations of simple ideas
or groups of ideas, which are conceived upon the hypothesis
that they correspond to definite, actually existing things, so
that the substance (substratum) presupposed for and in them
is considered as the point of union for the rest of the constitu
ent parts contained in the group of ideas. Of substance, man
has no clear conception ; it is, according to Locke, worthless.
According to him this conception is not limited to single things,
but he extends it also to the collective ideas of many things ;
thus an army, a herd of sheep, is just as much a substance as
a single man or one sheep. Relations arise from the comparison
of many things with one another, as the conceptions of cause
and effect, time — and place — relations, identity and diversity.
Ideas and their combinations are apprehended in language ;
therefore Locke begins in the third book with an investigation
upon language,. in so far as our knowledge, although relating
to things, is bound to words, and words are an indispensable
middle-term between thoughts and things. The extent and the
certainty of knowledge are on this account conditioned upon
the constitution and significance of words. In the fourth book
Locke pronounces the concluding judgment upon the extent
and the different grades of certainty in human knowledge.1
Leibnitz's attention was already turned from his own work to
that of the English philosopher by the above-mentioned edition
published by Locke himself in the "Bibliotheque universelle."
When later Locke's work reached his hands, he threw off, as
was his custom while he skimmed through the book, some
remarks ; 2 they follow here under the superscription : " 8ur
1 For the foregoing are of value: Hartenstein, Locke's Lehre von der
menschlichen Erkentitniss in Vert/leichung mit Leibniz1 s Kritik derselben.
Leipzig, 18(51. — Ueberweg, Gmndriss der Geschichte der Philosophic, 3 Theil.
Berlin, 1880.
2 They came into being after the year 1698. since mention is made in them
of Locke's Tract upon Education: Thoughts on Education, London, 169:>.
They were first printed in Some Familiar Letters between Mr. Locke and
Several of his Friends, London, 170K, pp. 1!X>-205.
LEIBNITZ'S CRITIQUE OF LOCKE
1" Essay de 1'entendeineut humaiii de Monsieur Lock.*'1 Leibnitz
sent it in accord with his pleasant custom to Thomas Burnett,
with whom he corresponded.12 Through him they came to the
knowledge of Locke, who, however, upon vain pretexts, de
clined every reply thereto.3 When Leibnitz received among
others the communication from Burnett (July 26, 1698), that
Locke had so far expressed his opinion that he for his part did
not sufficiently understand Leibnitz's remarks upon his book,
he resolved upon a remodelling of the same. Two fragments
of the year 1698 are thereupon at hand ; they are printed here
for the first time, under the superscription : " Echantillon 4 de
Reflexions sur le I. Livre de 1'Essay de I'Entendement de
rhomme. — Echantillon de Reflexions sur le II. Livre." Leib
nitz again sent them to Burnett; through whom Locke re
ceived them ; but this attempt also on Leibnitz's side remained
without result, as appears from Burnett's letter to Leibnitz
October 23, 1700.
1 On Locke's Essay on Human Understanding. See infra, pp. 13-19. — TR.
2 Leibnitz to Thomas Burnett, 7th-17th March, lb'96: " I found, also, finally,
a rough draught which I had had copied formerly, of some remarks I made
when running through the excellent essay of Locke upon Human Understand
ing; I take the liberty of sending you a copy." —Leibnitz to Th. Burnett,
17th-27th July, 1(397: "What I sent you of my reflections upon the important
book of Locke is entirely at your disposal, and you can communicate it to
whomever it seems good to you; and if it falls into his hands, or those of his
friends, so much the better; for that will give him an opportunity to instruct
us and to clear up the matter."
3 Highly characteristic is that which Burnett communicated to Leibnitz
upon the 23d of July, 1697: " I must tell you a joke of Locke's the other day,
on this matter. We beg*an to speak of the controversies of savants with those
of this country. He said: 'It seems to me we live very peaceably as good
neighbors of the gentlemen in Germany, for they do not know our books, and
we do not read theirs, so that the tale (la [? le — TR.] route) (? le rompte, the
account) was well adjusted on each side.'" — On the other hand, we find
a very dissenting judgment of Locke's upon Leibnitz and his remarks in
his letter to Dr. Molyneux, of April 10, 1*597: "I must confess to you that
Mr. L 's great name had raised in me an expectation which the sight of
his paper did not answer, nor that discourse of his in the ' Acta Eruditorum,'
which lie quotes, and I have since read, and had jiist the same thoughts of
it, when I read it, as I find you have. From whence I only draw this infer
ence, That even great parts will not master any subject without great thinking,
and even the largest minds have but narrow swallows." — Not less disparaging
is Locke's judgment upon Leibnitz in the next letter to Molyneux, of May 3,
1t>97. — The correspondence between Locke and Molyneux is contained in the
already quoted book: Some Familiar Letters betiveen Mr. Locke, etc.
4 Specimen of Reflections on Book I. of the Eaaaif on Human Understand
ing. Specimen of Reflections on Book II. See ////'/•</, pp. 'JO-iio. — TR.
UN HUMAN UNDERSTANDING
lu the year 1700 appeared the French translation of Locke's
work published by Pierre Coste;1 it was prepared according to
the fourth edition and contained accordingly the additions
which Locke had made to the previous editions of his book.
Leibnitz at once took occasion thereof to write a sketch for the
"Monatliche Auszug ~aus allerhand neu-herausgegebenen, niitz-
lichen und artigen Biichern," for the year 1700 (September, pp.
611-636). This follows here under Xo. III.3 together with the
supplement of the following year, 1701.4 In this sketch Leib
nitz discusses two of the weightiest of Locke's additions, filling
two separate chapters, viz.: chapter 33 of the second book,
wherein Locke treats of the Association of Ideas, and then
chapter 19 of the fourth book, in which he discourses of
Enthusiasm.
Through the French translation Leibnitz first gained real
access to Locke's work.5 He recognized the importance of its
contents in its fullest extent ; at the same time the extremely
large circulation and the universal recognition, which ex
pressed itself through the editions following each other in
rapid succession, must have made upon him a deep impression.
Evidently for these reasons Leibnitz conceived the plan of
1 Essai Philosophique concernant Fentendement humain, ou Ton montre,
qnelle est 1'enteiidue de nos Connoissances certaines et la maniere dont nous y
parvenons, traduit de 1' Anglais de Mr. Locke par Mr. Pierre Coste, sur la
quatrieme edition, revue, corrigee et augmentee par 1'Auteur. A Amsterd..
1700. 4. This first edition of Coste's translation was not accessible to me : I
have been able to make use of the second : Essai Philosophique concernant,
etc. Traduit de 1'Anglois par M. Coste. Seconde edition, revue, corrigee, et
augmentee de quelques Additions importantes de 1'Auteur qui n'ont paru
qu'apres sa mort, et de quelques Remarques du Traducteur. A Amsterd.,
1729. 4.
2 I.e. " ' Monatliche Auszug ' (Monthly Abstract) of the various newly pub-,
lished, profitable, and pleasing books." — TR.
8 See infra, pp. 24>-38. — TR.
4 This " Monatliche Auszug " appeared in three annual sets from 1700-1702.
Guhrauer (Leibnitz's deutsche Schriflen, 2ter Band) has tried to prove in a
very complete excursus that Leibnitz was the real editor of this Journal.
Certainly the sketch of Locke's work originated with him.
5 Leibnitz to Thomas Burnett, 17th-27th July, 1()9G: "I could wish I had
the same knowledge of the English language " (as of the French) ; " but, not
having had the occasion for it, all I can do is to understand passably the books
written in this language. And at the age at which I have arrived," I doubt if
I could ever make myself better acquainted with it." — Leibnitz to Coste. of
June 16, 1701: "I have followed your French version, because I thought it
proper to write my remarks in French, since nowadays this kind of investiga
tion is but little in fashion in the Latin Quarter."
LEIBNITZ'S CRITIQUE OF LOCKE
answering Locke's work with a more extensive writing. It
grew out of the often hastily-thrown-off remarks which he
occasionally put on paper in the years following that of 1700,
in which he was not permitted to undertake any continuous
work.1 In order to obliterate the traces of this method of
work, Leibnitz considered it advisable, before he published it,
to submit his book, as to composition and style, to the judg
ment of a native Frenchman. This revision was protracted
until the year 1705, as appears from a writing which has no
signature.2 Another delay occurred by reason of the fact that
Leibnitz in the following year, 1706, entered into correspond
ence with Pierre Coste, the translator of Locke's work ; Ooste
told him (April 20, 1707) that the translation of Locke itself
would be examined and furnished with important improve
ments ; he would urgently advise him (Leibnitz) to put off
the publication of his work until he obtained a knowledge of
these changes of Locke. This further consideration, that he
learned of the dissenting opinions of Locke in his corre
spondence with Molyneux, as also Locke's death, which had
1 " I have made these remarks in the leisure hours when I was travelling or
at Herrenhausen, where I could not apply myself to researches which required
more care " (besoin 1 in sense of soin ? — TR.).1
2 "The frequent diversions to which I have been exposed have prevented
me from pushing forward my remarks. Besides, I have been obliged to divide
my time between the reading of your work and the commissions with which I
have been entrusted by the Count de Schwerin, of which I must give account
to him. You will find few remarks upon this paper; but I have taken the
liberty of changing in the work itself a very large number of places in reference
to which I did not at all hesitate when I saw that I could do this without dis
arranging the rest of the writing. I have not touched what is properly called
the style ; but the confidence with which you have honored me obliges me to
say to you here that it greatly needs amendment, and that you seem too much
to have neglected it. You know, sir, to what excess our French people have
carried their well- or ill-founded delicacy. Too long periods are distasteful ;
an And (Et) or some other word too often repeated in the same period offends
them: unusual constructions embarrass them; a trifle, so to speak, shocks
them. It is proper, however, to accommodate yourself to their taste if you
wish to write in their language: and, in case you should decide to print your
work, I believe you will do well to retouch it with a little more severity. I
am certain that you will not be displeased at the freedom with which I speak
to you, since it conies from a person devoted to your service." — Feb. 'J,
1705.
1 W. T. Harris, editor of the "Journal of Speculative Philosophy," suggests that per
haps the reading was besogne (work) — instead of besoin. So that the passage read,
" researches which required more work (or labor)." — TR.
ON HUMAN UNDERSTANDING 9
already followed in the year 1704, altered Leibnitz's original
plan.1
In order to obtain an easier entrance for his own ideas, and
at the same time to make his reader familiar with those of
Locke, Leibnitz had composed his work in the form of a dia
logue. Two friends, Philalethes and Theophilus, converse
together ; the first states the views of Locke, the second joins
thereto his own (Leibnitz's) remarks. This form of composi
tion Leibnitz thought of abandoning. He writes to Thomas
Burnett, May 26, 1706: "The death of Locke has taken away
my desire to publish my remarks upon his works. I prefer
now to publish my thoughts independently of those of
another." On the other hand, he remarks, wellnigh it seems
in the opposite sense, to the same, three years later, May 12,
1709: "My remarks upon the excellent work of Locke are
almost finished ; although we are not of the same opinion, I
do not cease to value it and to find it valuable."
Leibnitz's work remained, in form at least, unfinished ; a
magnificent torso, and unpublished.2 He turned to the compo
1 Leibnitz to Coste, June 1(5, 1707 : " The great merit of Mr. Locke, and the
general, esteem which his work has with so much justice gained, united to
some intercourse by letters which I have had the pleasure of having with my
Lady Masham, caused me to employ some weeks in remarks upon this impor
tant work, in the hope of conferring upon them with Mr. Locke himself. But
his deatli shocked me, and caused my reflections to be behindhand, although
they are finished. My purpose has been to throw light upon things rather
than to refute the opinions of another. I shall be delighted, however, sir, to
receive the additions and corrections of this excellent man, in order to profit
from them." — Leibnitz to Remond, March 14, 1714: "He (Hugony) has also
seen my somewhat extended reflections upon Locke's work, which treats of
Human Understanding. But I dislike to publish refutations of dead authors,
although they might appear during their lifetime and be communicated to the
authors themselves. Some minor remarks escaped me, I know not how, and
were carried to England by a relative of the late Mr. Burnett, bishop of Salis
bury. Locke having seen them, spoke of them slightingly in a letter to
Molyneux, which may be found among some posthumous letters of Locke. I
learned his opinion of them only from this impression. I am not astonished
at it: we differed a little too much in principles, and the views I advanced
seemed to him paradoxical. However, a friend more biassed in my favor and
less so in favor of Locke informs me that those of my reflections there inserted
appear to him the best of the collection. I do not adopt this view, not having
examined the collection."
'2 Over the Preface, which certainly was composed after the completion of
the entire work, Leibnitz has written as the title of the work : Nourvanx Essnis
*>t,r Ventendeme.nt par VAnteur di< si/steme dc V Harmonic pre.establie. In the
Preface itself he leaves out the word "humain." The superscription of the
10 LEIBNITZ'S CRITIQUE OF LOCKE
sition of the "Theodicy." For the first time, fifty years after
his death, it was sent to the press in " CEuvres Philosophiques
latines et franchises de feu Mr. de Leibnitz. Tirees de ses
manuscrits qui se conservent dans la bibliotheque Royale a
Hanovre, et publiees par Mr. Rud. Eric. Raspe. Avec une
Preface de Mr. Kaestner, Professeur en. Mathematiques a
Gottingen. A Amsterdam et a Leipzig, 1765." The present
impression has been newly compared with the original, so far
as it is still extant.1 The corrections in reference to the style
proposed by the native Frenchman are not taken into consider
ation, in order not to obliterate Leibnitz's style of expression ;
they relate, indeed, only to the first books.
In the preface to his work, in which Leibnitz has put
together the points of difference between his system and that
of Locke, he remarks in the first place that Locke's Essay upon
Human Understanding is one of the most beautiful and valua
ble works of its time ; that he has determined to make some
remarks upon it, because he himself has considered the same
subject for a long time, and deemed it a good opportunity to
create a favorable entrance for his own ideas in this wray.
His own system differs, in truth, from Locke's considerably, in
so far as Locke's is more closely related to Aristotle, his own,
on the other hand, to Plato ; Locke's is more universally com
prehensible, his own more abstract. Meanwhile, by clothing
his own remarks in the form of a dialogue between twro per
sons, one of whom presents Locke's views, the other joins
thereto his own, he hopes to avoid the dryness belonging to
abstract remarks ; at the same time the reader is spared the
labor of comparing the passages from Locke's essay under dis
cussion. — The first important point of difference, wherein
Leibnitz distinguishes himself from Locke, is in the ques
tion whether the soul is in itself empty like a tabula rasa, as
Aristotle had already maintained, and that it receives every
thing through sense-perceptions and experience, or whether
fourth book runs thus: Nowiecmx Essays sur V entendement ; in the case of
the three first books we find the superscription: Nouveaux Essais sur I'cn-
tendement humaine.
1 In the original, Leibnitz has enclosed the words of Philalethes, who states
the views of Locke, in [], perhaps as an indication that they are not his own.
Raspe has omitted them. — GERHARDT'S NOTE. In this translation Gerhardt's
use of [ ] has been strictly followed. — TR.
ON HUMAN UNDERSTANDING 11
the soul originally has the principles of many conceptions and
doctrines, as Leibnitz with Plato thinks. Hence arises another
question, whether all truths depend upon experience, or whether
there is still another principle. The senses are necessary for
our actual knowledge, but they give us only examples, i.e. in
dividual truths, which are not adequate for grounding the uni
versal necessity of a truth. The necessary truths, which are
found in pure mathematics, appear to rest upon other princi
ples, whose proof depends not upon experience and the testi
mony of the senses, — a point to be well considered. Logic,
metaphysics, ethics, are full of such truths, which can arise
only from such principles as are called innate. It is neverthe
less possible, continues Leibnitz, that my opponent is not
wholly remote from my view. For after he has rejected
innate ideas in the first book of his essay, he begins the second
book with the statement that the ideas which have not their
origin in sensation arise through reflection. What, however,
is reflection but a regard for what is in us and born in us ?
Such are the ideas of being, unity, substance, etc. If, thinks
Leibnitz, an understanding with his opponent might easily,
perhaps, be re-established in reference to the above, yet it
might create more difficulty in reference to the affirmation
that the soul does not always think, just as bodies do not
always have motion. To this Leibnitz opposes the statement
that bodies are always in motion and that a substance cannot
exist without activity ; there are in the soul a multitude of
impressions too small to be separately distinguished, but which,
however, united produce an activity, although simply inarticu
late, like the noise of the waves. These little perceptions are
of greater significance than we think. By means of these in
sensible perceptions the pre-established harmony between the
soul and the body is explained. In the same manner they are
of great importance for Physics, for thereupon rests the law
of continuity. These minute insensible perceptions are also
the reason why there are not two perfectly similar souls or
things of the same kind.
Another point of difference between Leibnitz and Locke is
in reference to the conception of the nature of Matter. Locke
considered the smallest particles of matter to be rigid bodies,
and therefore assumed that space is empty, else were any mo-
LEIBNITZ'S CRITIQUE OF LOCKE
tion impossible. Leibnitz, on the other hand, supposes space
to be filled with a fluid matter which is divisible to infinity ;
he calls especial attention to the fact that Locke, who at first
professed the gravitation theory of Newton constantly contested
by Leibnitz, viz. : that bodies work upon each other from any
distance whatever without touching, at a later period freed
himself from this assumption of Newton.
In discussing the concepts of space, time, and number, Locke
had remarked that only with these concepts may that of infinity
be united. Leibnitz agrees with him in this, that there is
neither an infinite space, nor an infinite time, nor an infinite
number, that in general the infinite is not given in that which
is put together out of parts. But the true infinite, Leibnitz
adds, is in the Absolute, which is without parts. From this
proceeds the concept of tlie finite through limitation.
In the beginning of the third book Locke had undertaken
a discussion of language as the expression of the forms of
knowledge. He had made thereby a distinction between nom
inal and real being. Leibnitz rejects this distinction as a
perplexing innovation. Things, Leibnitz affirms, have only
one essence, but different definitions of them, nominal and real
definitions, are possible.
The contents of the fourth book, in which is treated the
knowledge of the truth, gives Leibnitz no occasion to raise an
important point of controversy. In reference to the axioms,
whose indispensableness to scientific investigations Leibnitz
affirms, Locke contests, the former enters into a more protracted
explanation. In like manner he turns against Locke's notion
that the use of Logic is rather unfruitful.
ON LOCKE'S ESSAY ON HUMAN UNDERSTANDING,1
1696
[From the French]
I FIXD so many marks of unusual penetration in what
Mr. Locke has given us on the Human Understanding and
on Education, and I consider the matter so important, that
I have thought I should not employ the time to no purpose
which I should give to such profitable reading ; so much the
more as I have myself meditated deeply upon the subject
of the foundations of our knowledge. This is my reason for
putting upon this sheet some of the reflections which have
occurred to me while reading his Essay 011 the Understanding.
Of all researches, there is none of greater importance, since
it is the key to all others. The first book considers chiefly
the principles said to be born with us. Mr. Locke does not
admit them, any more than he admits innate ideas. He has
doubtless had good reasons for opposing himself on this point
to ordinary prejudices, for the name of ideas and principles
is greatly abused. Common philosophers manufacture for
themselves principles according to their fancy ; and the
Cartesians, who profess greater accuracy, do not cease to
intrench themselves behind so-called ideas of extension, of
matter, and of the soul, desiring to avoid thereby the necessity
of proving what they advance, on the pretext that those who
will meditate on these ideas will discover in them the same
thing as they ; that is to say, that those who will accustom them
selves to their jargon and mode of thought will have the
same prepossessions, which is very true.
My view, then, is that nothing should be taken as first
principles but experiences and the axiom of identity or (what
1 Erdmann, Leibnitii Opera Philosophica, pp. 136-139. — TR.
13
14 LEIBNITZ'S CRITIQUE OF LOCKE [i
is the same thing) contradiction, which is primitive, since
otherwise there would be no difference between truth and
falsehood; and all investigation would cease at once, if to
say yes or no were a matter of indifference. We cannot, then,
prevent ourselves from assuming this principle as soon as we
wish to reason. All other truths are demonstrable, and I value
very highly the method of Euclid, who, without stopping at
what would be supposed to be sufficiently proved by the so-
called ideas, has demonstrated (for instance) that in a triangle
one side is always less than the sum of the other two. Yet
Euclid was right in taking some axioms for granted, not as
if they were truly primitive and indemonstrable, but because
he would have come to a standstill if he had wished to reach
his conclusions only after an exact discussion of principles.
Thus he judged it proper to content himself with having
pushed the proofs up to this small number of propositions,
so that it may be said that if they are true, all that he says
is also true. He has left to others the task of demonstrating
further these principles themselves, which besides are already
justified by experience ; but with this we are not satisfied in
these matters. This is why Apollonius, Proclus, and others
have taken the pains to demonstrate some of Euclid's axioms.
Philosophers should imitate this method of procedure in order
finally to attain some fixed principles, even though they be
only provisional, after the way I have just mentioned.
As for ideas, I have given some explanation of them in a
brief essay printed in the " Actes des Sgavans " * of Leipzig for
November, 1684 (p. 537), which is entitled Meditationes de
Cognitione, Veritate, et Ideis;2 and I could have wished that
Mr. Locke had seen and examined it ; for I am one of the most
docile of men, and nothing is better suited to advance our
thought than the considerations and remarks of clever per
sons, when they are made with attention and sincerity. I
shall only say here, that true or real ideas are those whose
1 The " Aeta Eruditorum," Lipsiae, 1682-1731. — TR.
2 Gerhardt, Vol. 4, pp. 422-420 ; Erdmann, pp. 78-81. Translated in part by
Sir William Hamilton, Lectures on Loyic, Lect. X., H XXX., pp. 127-129,
Amer. ed. ; and complete by George M. Duncan, The Philosophical Works
of Leibnitz, pp. 27-32, New Haven: Tuttle, Morehouse, & Taylor, 1890;
also by Professor Thomas Spencer Baynes, in the Appendix to his edition
of the Port Royal Logic. — TR.
0 ON HUMAN UNDERSTANDING 15
execution we are assured is possible ; the others are doubtful,
or (in case of proved impossibility) chimerical. Now the
possibility of ideas is proved as much a priori by demon
strations, by making use of the possibility of other more
simple ideas, as a posteriori by experience ; for what exists
cannot fail to be possible. But primitive ideas are those
whose possibility is indemonstrable, and which are in truth
nothing else than the attributes of God.
I do not find it absolutely essential for the beginning or for
the practice of the art of thinking to decide the question
whether there are ideas and truths born with us ; whether they
all come to us from without or from ourselves ; we will reason
correctly provided we observe what I have said above, and
proceed in an orderly way and without prejudice. The ques
tion of the origin of our ideas and of our maxims is not pre
liminary in Philosophy, and we must have made great progress
in order to solve it successfully. I think, however, that I can
say that our ideas, even those of sensible things, come from
within our own soul/ of which view you can the better judge by
what I have published2 upon the nature and connection of sub
stances and what is called the union of the soul with the body.
For I have found that these things had not been well under
stood. I am nowise in favor of Aristotle's tabula rasa; and
there is something substantial in what Plato called reminis
cence. There is even something more ; for we not only have a
reminiscence of all our past thoughts, but also a presentiment
of all our future thoughts. It is true that this is confused,
and fails to distinguish them, in much the same way as when
I hear the noise of the sea I hear that of all the particular
waves which make up the noise as a whole, though without
discerning one wave from another. Thus it is true in a cer
tain sense, as I have explained, that not only our ideas, but
also our sensations, spring from within our own soul, and that
the soul is more independent than is thought, although it is
always true that nothing takes place in it which is not deter-
1 The French is : " de nostre propre fonds." — TR.
2 In the "Journal des Savants," June, Ki'Jo. For the piece, cf. Gerhardt,
Vol. 4, pp. 477 sq. (first sketch 470 sq.) ; and the portion of his introduction
and notes referri7i£ to the same, Vol. 4, pp. 414-417; Erdmann, pp. 124-128;
cf. also pp. 129-130. For the translation, Appendix, pp. .— TB.
16 LEIBNITZ'S CRITIQUE OF LOCKE
mined, and nothing is found in creatures that God does not
continually create.
In Book II., which conies to the details of ideas, I admit that
the reasons brought forward by Mr. Locke to prove that the
soul sometimes exists without thinking of anything, do not ap
pear to me convincing, unless he gives the name of thoughts to
those perceptions only which are sufficiently noticeable to be
distinguished and retained. I hold that the soul (and even the
body) is never without action, and that the soul is never with
out some perception : even in dreamless sleep we have a con
fused and dull sensation of the place where we are ; and of
other things. But even if experience should not confirm the
view, I believe that it may be demonstrated. It is much the
same as we cannot prove absolutely by experience whether
there is a vacuum in space, and whether there is rest in matter.
Nevertheless, questions of this kind appear to me, as well as
to Mr. Locke, to be decided demonstratively.
I admit the difference which he puts with much reason be
tween matter and space ; but as for the vacuum, many clever
people have believed in it. Mr. Locke is of this number. I
was nearly persuaded of it myself ; but I gave it up long ago.
And the incomparable Mr. Huygens, who was also for the
vacuum and the atoms, began at last to reflect upon my
reasons, as his letters can testify. The proof of the vacuum
derived from motion, of which Mr. Locke makes use, assumes
that body is originally hard, and that it is composed of a cer
tain number of inflexible parts. For in this case it would be
true, whatever finite number of atoms might be taken, that
motion could not take place without a vacuum. But all the
parts of matter are divisible and even pliable.
There are also some other things in this second book which
arrest my attention: for example, when it is said (chap. 17)
that infinity should be attributed only to space, time, and num
bers. I believe, indeed, with Mr. Locke that, properly speak
ing, we may say that there is no space, time, nor number which
is infinite, but that it is only true that however great * may be
1 Gerhardt's text seems here, for some reason, to be defective. It reads
thus : " Mais qu'il est settlement vray que pour grand que luy sans fin," etc.
Erdmann's seems the more correct, and is therefore followed in the translation.
It reads thus: "Mais qu'il est seulement vrai que pour grand que soit un
espace, un terns, ou un nombre, il y en a toujours un autre plus grand que lui
i] ON HUMAN UNDERSTANDING 17
a space, a time, or a number, there is always another greater
than it without end ; and that thus the true infinite is not
found in a whole composed of parts. It is none the less, how
ever, found elsewhere ; namely, in the absolute, which is with
out parts, and which has influence over compound things,
because they result from the limitation of the absolute. The
positive infinite, then, being nothing else than the absolute, it
may be said that there is in this sense a positive idea of the
infinite, and that it is anterior to that of the finite. For the
rest, in rejecting a composite infinite, we do not deny the
demonstrations of the geometers cle Seriebus infinitis, and par-
ticul,arly what the excellent Mr. Newton has given us, not to
mention my own contributions to the subject.
As for what is said (chap. 30) cle ideis adcequatis, it is
allowable to give to the terms the signification wrhich one finds
pertinent. Yet without finding fault with Mr. Locke's mean
ing, I put degrees in ideas, according to \vhich I call those
adequate in which there is nothing more to explain, much the
same as in numbers. ISTow all ideas of sense-qualities, as of
light, color, heat, not being of this nature, I do not reckon
them among the adequate. So it is not through themselves,
nor a priori, but through experience, that we know their reality
or possibility.
There are further many good things in Book III. in which
he treats of words or terms. It is very true that everything
cannot be defined, and that sense-qualities have no nominal
definition : thus they may be called primitive in this sense ; but
they can none the less receive a real definition. I have shown
the difference between these two kinds of definition in the
meditation1 cited above. The nominal definition explains the
name by the marks of the thing; but the real definition makes
known a priori the possibility of the thing defined. For the
rest, I strongly commend Mr. Locke's doctrine of the demon-
strability of moral truths.
The fourth or last book, which treats of the knowledge of
truth, shows the use of what has just been said. I find in it,
as well as in the preceding books, an infinite number of beauti-
sans fin." p. 138 a. Cf. also Leibniz's Neio Essays concerning the Human
Understanding. — A Critical Exposition, by John Dewey, Ph.D. pp» 190.
Chicago: S. C. Griggs & Co., 1888. — TR.
1 I.e. Meditationes de Cognitionc, Veritate, et Ideis. — TR.
C
18 LEIBNITZ'S CRITIQUE OF LOCKE [i
ful reflections. To make suitable remarks upon them would
be to make a book as large as the work itself. It seems to me
that the axioms receive therein a little less consideration than
they deserve. The apparent reason for this is that, excepting
those of the mathematicians, we ordinarily find none which
are important and solid: I have tried to remedy this defect. I
do not despise identical propositions, and I have found that
they are of great use even in analysis. It is very true that
we know our own existence by an immediate intuition, and
that of God by demonstration; and that a mass of matter,
whose parts are without perception, cannot make a thinking
whole. I do not despise the argument invented some centuries
ago by Anselm, archbishop of Canterbury, which proves that
the perfect being must exist ; although I find that the argu
ment lacks something, because it assumes that the perfect
being is possible. For if this single point were proved in addi
tion, the whole demonstration would be complete.
As for the knowledge of other things, it is very well said,
that experience alone does not suffice for a sufficient advance
in Physics. A penetrating mind will draw more conclusions
from some quite ordinary experiences, than another could draw
from the most choice ; besides, there is an art of experimenting
upon and, so to speak, questioning nature. Yet it is always
true that we can make progress in the details of Physics only
in proportion as we have experience.
Our author shares with many able men the opinion that the
forms of logic are of little use. I should be quite of another
opinion, and I have often found that the paralogisms, even of
mathematics, are the faults of form. Mr. Huygens has made
the same observation. Much might be said upon this point,
and many excellent things are despised because the use of
which they are capable is not made of them. We are inclined
to despise what we have learned in the schools. It is true we
learn there many useless things ; but it is good to exercise
the function delta Crusca,1 i.e. to separate the good from the
bad.
1 "La Crusca, a celebrated academy of Florence, founded in 1582, for the
purpose of maintaining the purity of the Italian language, that is to say, of
separating the bran (crusca) from the flour : hence the name." Duncan's note.
Philos. Works of Leibnitz, p. 378.
!] ON HUMAN UNDERSTANDING 19
Mr. Locke can do this as well as any one whatsoever ; and in
addition he gives us important thoughts of his own invention ;
his penetration and fairness appear everywhere.1 He is not
only an assay er, but he is also a trans muter by the increase of
good metal he gives. Should he continue to present it to the
public, we should be greatly indebted to him.
1 Erdmann omits this clause. — TR.
II
SPECIMEN OF THOUGHTS UPON THE FIEST BOOK
OF THE ESSAY OX HUMAN UNDERSTANDING
[From the French]
Ix order to prove that there are no ideas born with us, the
excellent author of the Essay on Human Understanding ad
duces experience, which shows us that we need external occa
sions in order to think of these ideas. I agree with him, but
it does not seem to me that it follows that the occasions which
cause us to see them, cause them to spring into being. And
this experience cannot determine whether it is through immis-
sion of a species or by impression of outlines upon an empty
tablet, or whether it is by the development of what is already
in us that we perceive ourselves. It is not extraordinary that
there be somewhat in our mind of which we are not always
conscious. Reminiscence shows us that we often have diffi
culty in remembering what we know, and in seizing what is
already in the enclosure and possession of our understanding.
This proving to be the truth in acquired knowledge, nothing
prevents its being also true in the case of that which is innate.
And, indeed, there is still more difficulty in perceiving this
last, since it has not yet been modified and detailed by ex
perience, as is the acquired, of which often the circumstances
remind us.
The author undertakes to show in particular that impossibil
ity and identity, whole and part, etc., are not innate ideas. But
I do not understand the force of the proofs he brings. I ad
mit that it is difficult to make men perceive distinctly these
metaphysical notions, for abstraction and thought cost them
effort. But one may have in himself that which he has diffi
culty in distinguishing there. Something else, however, than
20
i] ON HUMAN UNDERSTANDING 21
the idea of identity is necessary to answer the question, which
is here proposed, viz. : Whether Euphorbus and Pythagoras
and the cock,1 in which the soul of Pythagoras dwelt for some
time, were always the same individual, and it does not at all
follow that those who cannot solve this question have no idea
of identity. What is clearer than the ideas of geometry ?
Yet there are some questions which we have not yet been able
to decide. But that one which considers the identity of Pytha
goras following the story of his metempsychosis is not one of
the most impenetrable.
Regarding the idea of God, he brings forward examples of
some nations who have had no such knowledge. M. Fabritius,
a very distinguished theologian of the late Elector Palatine
Charles Louis, has published the " L'Apologie du genre humain
contre Paccusation de 1'Atheisme," in which he replies to such
passages as are here cited. But I do not enter into this dis
cussion. Suppose there are men, and even peoples, who have
never thought of God; we may say that this fact proves only
that there has not been an occasion sufficient to awaken in
them the idea of the supreme substance.
Before passing to the complex principles or primitive truths,
I will say that I agree that the knowledge, or better, the actual
consideration (envisagement),of ideas and truths is not innate,
and that it is not necessary that we have distinctly known
them in a former state of being, according to Plato's doctrine
of reminiscence. But the idea being taken for the immediate
internal object of a notion, or of what the logicians call an
incomplex term, there is nothing to prevent its always being
in us, for these objects can subsist when they are not per
ceived. Ideas and truths may, furthermore, be divided into
primitive and derivative : the knowledge of the primitives
does not need to be formed ; they must be distinguished only ;
that of the derivative is formed by the understanding and by
the reason upon occasion. However, we may say in one sense,
that the internal objects of this knowledge, that is to say, the
ideas and truths themselves, primitive as well as derivative,
are all in us, since all the derivative . ideas and all the truths
deduced from them result from the relations of primitive ideas
which are in us. But usage makes it customary to call innate
: Cf. Locke, Philos. Works (Bohn's ed.), Vol. 1, p. 181 sq., and note. — TR.
22 LEIBNITZ'S CRITIQUE OF LOCKE [n
the truths to which credence is given as soon as they are
heard, and the ideas whose reality (that is to say, the possibility
of the thing which it represents) is of the number of these
truths, and needs not to be proved by experience or by reason ;
there is then considerable ambiguity in this question, and it
suffices at the last to recognize that there is an internal light
born with us, which comprises all the intelligible ideas and all
the necessary truths which are only a result of these ideas and
need not experience in order to be proved.
To reduce, then, this discussion to something practical, I
believe that the true end one should have is the determination
of the grounds of truths and their origin. I admit that con
tingent truths, or truths of fact, come to us by observation
and experience ; but I hold that necessary derivative truths de
pend upon demonstration, i.e. upon definitions or ideas, united
with the primitive truths. And the primitive truths (such as
the principle of contradiction) do not come at all from the
senses or from experience, and xjannot be perfectly proved, but
from the natural internal light, and this is what I mean in
saying that they are innate. The geometers also have very
well understood this. They could prove passably their proposi
tions (at least, the most important of them) by experience, and
I do not doubt that the ancient Egyptian and the Chinese
had such an experimental geometry. But the true geometers,
above all, the Greeks, have desired to show the force of rea
son, and the excellence of science, by showing that they can
in these matters foresee everything, by the internal light in
advance of experience. It must also be admitted that experi
ence never assures us of a perfect universality, and still less
of necessity. Some of the ancients laughed at Euclid because
he proved what a fool even is not ignorant of (as they say), viz. :
that in a triangle two sides together are greater than the third.
But those who know what genuine analysis is, are much
obliged to Euclid for his proof. And it is much that the
Greeks, if less exact in other things, have been so much so in
geometry. I attribute it to providence; and I believe without
that we should hardly know what demonstration is. I also
believe that it is principally in that respect that we are thus
far superior to the Chinese.
But it is needful further to look a little at what our clever
n] ON HUMAN UNDERSTANDING 23
and celebrated author says in chapters 2 and 3, to sustain his
point that there are no innate principles. He is opposed to
the universal consent alleged in their favor, maintaining that
many races doubt even this famous principle that two contra
dictories cannot be true or false at once, and that the greater
part of the human race ignores it altogether. I admit that
there are an infinite number of persons who have never made
a statement of them. I have indeed seen authors who desired
to refute them, apprehending them, without doubt, wrongly.
But where shall we find one who does not avail himself of
them in practical life, and who is not offended with a liar who
contradicts him ? Nevertheless, I do not ground myself wholly
upon universal consent ; and as for propositions which are ap
proved as soon as they are proposed, I admit that it is not at
all necessary for them to be primitive or proximate to them,
for they may be very common facts. As for this statement
which teaches us that one and one make two (which the author
brings forward as an example), it is not an axiom, but a defini
tion. And when he says that sweetness is a different thing
from bitterness, he states only a fact of primitive experience,
or of immediate perception. Or better, we have only to say
that the perception of what is understood by the term sweet
ness is different from the perception of that which is under
stood by the term bitterness. I do not here distinguish at all
the practical truths from the speculative; they are always the
same. And as we can say that it is one of the most manifest
truths, that a substance whose knowledge and power are
infinite should be honored, we can say that it emanates at
once from the light which is born with us, provided one can
give his attention to it.
SPECIMEN OF THOUGHTS UPON THE SECOND
BOOK
[From the French]
IT is very true that our perceptions of ideas come either
from the external senses or from the internal sense, which may
be called reflection ; but this reflection is not limited to the
24 LEIBNITZ'S CRITIQUE OF LOCKE [n
operations alone of the mind, as is stated (chap. 1, § 4) ; it
reaches even to the mind itself, and it is in the consciousness
of self that we perceive substance.
I admit that I am of the opinion of those who believe that
the soul always thinks, although often its thoughts are too
confused and too feeble for it to be able distinctly to remember
them. I believe I have certain proofs of the continual activity
of the soul, and I believe also that the body can never be
without motion. The objections raised by the author (Book
II., chap. 1, §§ 10 to 19) can be easily met by what I have just
said or am about to say. They are based upon the experience
of sleep, which is sometimes dreamless ; and in fact there are
some persons Avho do not know what it is to dream. How
ever, it is not always safe to deny everything that is not per
ceived. It is much the same as when there are people who
deny the corpuscles and insensible motions, and laugh at the
particles because they cannot be proved. But some one will
tell me that there are proofs which force us to admit them.
I reply that there are in like manner proofs which compel us
to admit perceptions which are not marked enough for us to
remember them. Experience, furthermore, favors this view ;
for instance, those who have slept in a cold place notice that
they have had while sleeping a confused and feeble sensation.
I know a person who wakes up when the lamp which he
always keeps lighted at night in his room goes out. But here
is something more precise, and which shows that if we did
not always have perceptions, we could never be waked up
from sleep. Let a man who is sleeping be called by several
persons at once, and let it be assumed that the voice of each
by itself is not loud enough to awake him, but that the noise
of all these voices together awakes him : let us take one of
them ; it is very necessary that he be touched by this voice in
particular, for the parts are in the whole, and if each one by
itself does nothing at all, the whole will do nothing, either.
Yet he would have continued to sleep, if the voice had been a
single one, and that, too, without remembering that he had been
called. Thus there are some perceptions too feeble to be
noticed, although they are always retained, but among an infi
nite number of other small perceptions which we have con
tinually. For neither motions nor perceptions are ever lost;
n] ON HUMAN UNDERSTANDING 25
both continue always, only becoming indistinguishable through
composition with many others. One might reply to this
reasoning, that each voice by itself effectively touches the
body, but that a certain quantity of it is needed in order that
the motion of the body may reach the soul. I reply, that the
least impression reaches the entire body, and consequently to
that part whose motions correspond to the actions of the soul.
And accordingly no principle of limitation can be found, how
ever necessary a certain quantity may be. I do not wish to
insist upon the interest that the immortality of the soul has
in this doctrine. For if the soul is passive, it is also without
life, and it seems that it can be immortal only by grace and by
miracle — a view which there is reason to disapprove. I admit,
however, that our interest is not the measure of truth, and I
do not wish to mix here theological reasons with those of
philosophy.
Ill
[From the German~\
Essai Philosophique concernant 1'Entendement humain, oil Ton montre,
quelle est 1'eutendue de nos connoissances certaiues et la mauiere dont nous y
parvenons, traduit de I'Anglois de Mr. Locke par Mr. Pierre Coste, sur la
quatrieme edition, revue, corrigee et augmentee par 1'Auteur. A Amsterd.
1700 in -ito.
Philosophischer Versuch, betreffend den Menschlichen Verstand, ahvo
gewiesen wircl, wie weit sich uusre gewisse Erkaiidtniissen erstrecken, uud
aut' wass Weise wir darzii gelangen ; ausz den Englischen iibersetzet von Hrn.
Peter Coste nach der vierten voni Autor selbst iibersehenen, verbesserten und
vermehrten Edition. 5. Alph. 12. Bog.
IT 1 is unnecessary for us to give a complete abstract of this
notable book, after the author himself has relieved us of this
task, since in the year 1688 he prepared such an abstract for
Mr. Clerc for insertion in his "Bibliotheque universelle," 2
T. VIII., p. 49 sqq., before he gave it to the press. In the year
1690 it appeared first in London in folio, and Mr. Clerc again
published lengthy excerpts in the said " Bibliotheque univer-
selle," T. XVII., p. 399. Soon afterwards a new English edition
appeared, enlarged with many pieces, and in particular with
an entire chapter 3 on Identity and Diversity, which he treats
in an exceedingly clear and excellent manner.
In the second edition mentioned, Locke acknowledges that
he erred in the first edition when he assumed, in accordance
with the common view, that what brings the will to any change
of action in the course of arbitrary actions is the assurance of
a much greater good. For when he considered the matter
more carefully, he found that a present unrest which consists
in desire or is constantly accompanied by the same, places its
limits upon the will. For the reasons for this view, see Book
1 From the " Monatliche Auszug," Sept. 1700, pp. ()ll-(i:>(i. — TR.
2 " Bibliotheque universelle et historique," Amsterdam, 1686-1(>93. — TR.
3 In the present edition this chapter is 27 in the second book. — Gerhardt's
note.
26
in] ON HUMAN UNDERSTANDING 27
II., chap. 21. He will gladly, however, be informed of a bet
ter view. Some time after, a third, and in the year 1699, a
fourth, edition appeared, in which last edition Locke either
further explained his previous thoughts by many additions or
supported them by wholly new grounds. Peter Coste made
his translation on the basis of this edition, and when Locke
sent him his manuscript, had worked upon the same for more
than two years. Locke himself considered this translation a
good one and presented his thanks accordingly, so that con
sequently it must be the more welcome by a great deal to us.
To enumerate all the new additions would take too long;
hence we will content ourselves with the mention of the two
most important, which make two separate chapters, of which
the first is Book II., chap. 33, and treats of the Association of
Ideas.
Locke says there is almost no one who does not find
something in the opinions, conclusions, and actions of other
people which seems to him fantastic and extravagant, and is so
in fact. Every one may have eyes keen-sighted enough to
mark the least fault of this kind in the case of another, if
only it may be distinguished from his own, and he himself may
have sufficient understanding to condemn the same, although
he also may have in his own opinions and his own conduct the
greatest errors of which he might be aware, and of which,
where not impossible, he may yet with difficulty be convinced.
This arises, he continues, not merely from self-love, although
this passion has often a great part therein. For one daily sees
such people lying sick with the same disease, who are otherwise
skilful and whole enough to make nothing of their own merits.
This defect of reason is customarily ascribed to education
and to the force of prejudice, and this, according to the common
opinion, not without cause, but according to Locke's statement,
this explanation reaches not to the root of the disease, and does
not show completely its origin and peculiarity.
He himself explains it as follows : Some of our ideas [his
own words] have among themselves an exact correspondence
and connection. The obligation and highest perfection of our
reason consists in the fact that it reveals such ideas and holds
them together in the selfsame unity and correspondence as
that which is grounded in their particular nature. There is
28 LEIBNITZ'S CRITIQUE OF LOCKE [in
besides this another bond of ideas which depends upon chance
or custom, so that the ideas which naturally are wholly unre
lated become so exactly united in the minds (esprit l ) of some
men, that they can with difficulty be separated from one
another. They accompany one another constantly, and one can
no sooner present itself to the understanding (intellectui)
than the others or, indeed, more of them, so united are they,
appear also, nor can they at all be separated from one another.
This association of ideas, which the mind makes in itself
either voluntarily or by chance, is the sole source of the defect
of which we now speak. And as this strong union of ideas is
not originally caused by nature, it is for this reason wholly dif
ferent in different persons, viz. : according to their different
inclinations, education, and self-interests.
That there are such associations of ideas, which custom
begets in the minds of most men, no one, according to Locke's
statement, can doubt, who with much earnestness considers
himself and other people. And to this cause can perhaps with
convenience and reason be ascribed the greater part of those
sympathies and antipathies which one finds among men, and
which work as strongly and produce as regular effects, as if
they were natural, which fact then makes them to be called so,
although at first view they had no other origin than the chance
connection of two ideas, which the strength of a first impres
sion, or of an excessively great compliance, so firmly united,
that they always thereafter remain together in the mind of
the man, as though only a single idea. Locke, however, in no
respect denies that there are wholly natural antipathies which
depend upon our original constitution and are born, with us.
He believes, however, that with proper consideration man
would recognize the most of those which have been regarded
as natural, as in the beginning caused by impressions which
were not heeded, whether they were suggested sufficiently
early or through a ridiculous fancy. Locke notices incidentally
the difference which may be made between natural and ac
quired antipathies, so that those who have children or who
1 This word I have voluntarily retained here and for the most part in what
follows, because it cannot be expressed quite clearly in German. — Leibnitz's
note, Gerhardt, p. 27.
Perhaps we should retain the word " esprit " in English. — TB.
m] ON HUMAN UNDERSTANDING 29
must educate them, may see how much heed they should take
of this principle, and with what care this disorderly union of
ideas in the mind of the youth should be prevented.
He thereupon points out by some examples how such a union
of ideas, which are not of themselves united, yet depend one
upon another, is sufficient to impede our moral and natural
action, yea more, our notions themselves.
The ideas of goblins or of spirits agree as little with dark
ness as with light ; if, however, a foolish maid instils and
awakens these different ideas in the mind of a child, as though
they were connected with each other, the child during his entire
life will perhaps not be able to separate them from each other;
so that the darkness ever more will seem to him to be accom
panied with these horrible ideas.
If any one has suffered a grievous wrong on account of
another, he thinks very often of the persons and the deed, and
while he thus strongly or for a long time thinks thereupon, he
at the same time glues these two ideas together so firmly, that
he makes them almost one, as it were, and never remembers the
person but that the wrong received also enters his head. And
while he can scarcely distinguish these two things, he has just
as much aversion for the one as for the other. Thence it
comes, Locke adds, that hatred arises from slight and worth
less reasons, and quarrels are taken up and continued in the
world.
One of Locke's friends was wholly cured of madness by a
certain man through a very painful operation, for which service
he acknowledged himself under great obligation to him through
out his life, as he was so circumstanced that he required from
no one a greater service during his life. Eeason or gratitude
might suggest to him what they would, yet he could never
bear the sight of this surgeon. For as the sight of him always
brought again to mind the idea of the very great pain which
he had been obliged to endure at his hands, he could not endure
this idea, so violent were the impressions it produced in his
mind.
Many children hold their books, which were the occasion
hereto, accountable for most of the ill treatment they endured
at school, and they unite these ideas so well that they regard
a book with great disgust, and all their life study and books
30 LEIBNITZ'S CRITIQUE OF LOCKE [m
cannot win their love, because to them reading, which might
otherwise have greatly delighted them, became a genuine tor
ture.
An example notable for its singularity is the following which
an eminent man, who assured him he had himself seen it, re
lates to Locke : A young man had learned to dance very prettily
and perfectly. There chanced to stand, however, in the hall
where he first learned, an old trunk, the idea of which com
bined so imperceptibly with his turns and steps in the dance,
that although he could dance incomparably well in this hall,
he could do this only when the old trunk was there ; in other
places, however, he could not dance at all, unless the old trunk
itself or one like it stood in its accustomed place.
The habitus intellectuales which are contracted through such
association of ideas, are, as Locke further informs us, just as
strong and numerous, even though very little heeded. Sup
posing the ideas of being and matter were very strongly united,
either by education or by an excessively great application to
these two ideas, according as they are combined in the mind,
what notions and reasonings w^ould they not produce concern
ing different spirits ? If a custom accepted from childhood
up had united a form or figure with the idea of God, into what
absurdities would such a thought in the contemplation of deity
not plunge us ? We shall no doubt find, Locke adds, that it
is nothing else than similar ill-grounded and unnatural combi
nations of ideas, which break the path for the many conflicting
sects in philosophy and religion; for it is not to be supposed
that each member of those different sects is willingly deceived,
and against his better knowledge and conscience rejects the
truth demonstrated to him by clear evidence. It is indeed
certain that sometimes interest assists greatly in this sort of
thing, yet no one could affirm that it could captivate and lead
astray whole societies, so that they all, none excepted, should
affirm plain and deliberate falsehoods. For it must be that
some at least do what others pretend to do, viz. : seek truth
sincerely.
Therefore there must be something which blinds their un
derstanding and hinders them from recognizing the falsehood
of what they consider as pure and refined truth. If now we
investigate accurately what takes reason prisoner and darkens
in] ON HUMAN UNDERSTANDING 31
the understanding of otherwise sincere people, we find that it
is simply and solely some free ideas, which, properly speaking,
really have no bond among themselves, but which, by educa
tion, custom, and uninterrupted action on their part, are so
united in the mind that they can no more be separated and
distinguished from one another than a single idea. Thence it
comes, Locke continues, that often the crudest things are
taken for worthy opinions, absurdities for demonstrations, and
intolerable and absurd results for strong and fluent reason
ings.
The other chapter we promised to present, treats of Enthu
siasm, and is the 19th in the 4th book. Locke's thoughts
thereupon are as follows : —
Whoever will earnestly seek for truth must first before all
things acquire a love for it. Whoever does not love the truth,
to him we must necessarily attribute the opposite. Hence we
can rightly say, that among .those who pretend to seek it,
there are very few who really love it. We may recognize a
genuine seeker of the truth, since he does not assume for a
statement any greater certainty than the proofs upon which
he grounds it warrant. Whoever steps beyond this limit lays
hold of the truth not out of love for it, but from another indi
rect purpose. For while the unquestionable clearness of a
statement truly consists in the evidence for it (excepting
those which are sufficiently clear of themselves), yet it is
plain that so far as space is given to assent beyond the unques
tionable clearness of a proposition, the remaining portion of
the assurance is not drawn from love for the truth, but from
another passion. For as it is impossible that love for the
truth can bring any one to give to any proposition an assent
greater than that certified by the truth itself, just so is it also
impossible that any one out of love for the truth can assent to
a statement in view of evidence of such a character that from
it he cannot see whether the statement is true ; which would
be actually equivalent to the assumption that the proposition
is a truth because possibly, or, indeed, probably, it seems not
to accord with the truth.
Locke adds, it follows indisputably from this evil disposi
tion of the mind, that men assume the authority to dictate
their own opinions to others. For how should one who has
32 LEIBNITZ'S CRITIQUE OF LOCKE [in
imposed on his own belief, not be willing also to impose on
the belief of others ? How is it to be expected that one will
use valid arguments and proofs in dealing with others, who is
riot accustomed to use them in dealing with himself, who does
violence to his own powers, who tyrannizes over his own mind,
and misuses the advantage which, truth alone has, viz. : that it
assents to nothing but what is indisputably true ?
After Locke has laid this foundation, he proceeds to the in
vestigation of Enthusiasm, to which some people ascribe as
much power as to faith and reason, and would establish revela
tion without the aid of reason, whereby, however, they would
at once destroy both reason and revelation, and without any
reason erect in their place the fancies forged in their own
brain, which they choose as the plumb-line of their opinions
and conduct. Eeason is nothing else than a natural revela
tion, whereby God bestows upon men that portion of truth
which he has poured into the capacity of their natural powers.
Revelation is natural reason, enlarged by a new set of discov
eries flowing immediately from God, the ground (raison) of
which is the truth by testimony and proof they otter that
these discoveries actually come from God.1 Whoever, there
fore, destroys reason to make room for revelation, extin
guishes both these lights at the same time. As, however, men
find that an immediate revelation is a much easier means of
strengthening their opinions and of directing their conduct
than the labor of arranging all according to strict reasoning,
which is usually irksome, prejudiced, and for the most part
without successful progress ; so it is not to be wondered at
that they often pretend revelations and persuade themselves
that God directs them in particular as regards their actions
and opinions, and especially in those things which they cannot
justify by the principles of reason. If their minds are once
possessed with this thought, the most absurd opinions winch
are firmly impressed upon their fancy, must seem to be illu
minations coming from the Spirit of God and having divine
authority. Every extraordinary thing to which they are led
by a strong impulse, they consider as certainly a divine call
1 On this whole discussion, cf. an article by the translator entitled "Reve
lation, Inspiration and Authority," in "The Andover Review," April 1891.
— TR.
m] ON HUMAN UNDERSTANDING 33
which they must follow, and as a command from, on high in
whose execution it is impossible to err.
This is, properly speaking, what is meant by Enthusiasm,
which is not adjusted to reason nor to divine revelation, but
springs forth only from the imagination of a heated and con
ceited spirit, and which, as soon as it has taken a little root,
plays much more strongly upon the opinion and actions of
men than reason or revelation separately or together.
Although now the extravagant actions and opinions, wherein
enthusiasm has involved men, should spur them on to be more
on their guard and to avoid the false principia, which lead
astray both their belief and their conduct; yet through its
love for the extraordinary, through its ease and illumined by
its glory, and through its extraordinary paths to knowledge it
has come to pass that the laziness, ignorance, and vanity of
many are so tickled, and they are brought to such a point, that
after they are captivated by such ways of an immediate reve
lation, of an illumination without search, of a certainty with
out proof and investigation, it is very difficult to bring them
out of it again.
They are transported beyond reason, and reason in their
case perishes. They see a light infused into their understand
ing and can no longer be deceived. This light visibly appears
as the clearest sunbeam and requires no other proof than its
own clearness. They feel, according to their statements, the
hand of God moving them within ; they feel the impulses of
the Spirit, and cannot be mistaken in their feeling. Thus
they persuade themselves that reason has nothing to do with
what they see and feel in themselves. The things which they
clearly experience are beyond all doubt, and need no proof ;
and so of all the rest of their strange talk. They are sure of
these things because they are sure of them, and their opinions
are correct because they are firmly fixed in their mind. For
this is the upshot of their words when stripped of the meta
phors of hearing and feeling in which they are clothed.
Locke investigates the g'round of, this inner light and feel
ing, upon which these people so firmly base themselves, and
speaks thus : Is this seeing of the light a perception of the
truth of a certain particular statement,, or perhaps of this, that
it is a revelation from God ? Is this feeling a perception of
34 LEIBNITZ'S CRITIQUE OF LOCKE [in
an inclination, which, comes from a fancy to do something, or
from the spirit of God, which begets in it this inclination?
These are two wholly different feelings, which must be care
fully distinguished from one another if we would not deceive
ourselves. I can perceive the truth of a proposition; but I
cannot thereby know as yet whether it is an immediate revela
tion from God. I can perceive the truth of a proposition in
Euclid without its being or my knowing that it is a revelation.
I may also know that I did not attain this knowledge through
natural, means, thence may indeed conclude that it is revealed
to me, but I cannot thereby yet know it is a revelation from
God; because there may be minds which without a divine
commission for this work arouse these ideas in me and set
them in such order in my mind that I may perceive their con
nection. So that the knowledge of a proposition, which enters
my head, I know not how, is thus not an evidence that it
comes from God. Still less is a firm persuasion that this
fancy is true, a certain evidence that it comes from God, or
that it is true.
We may call such a fancy sight or light, yet it is nothing
more than belief and confidence.1 For if the proposition under
discussion be one which they have imagined, but do not know
to be true, it cannot be seeing, but believing. One may also
give to such fancy any name he pleases. What I believe, I
must put forth as true upon another's testimony, and must
know certainly in the case that this testimony is given ; for
without this my belief would be groundless. I must see
whether God reveals this to me, or whether I see nothing.
Thus the issue is, that I know how I am to know that God
reveals something to me, that this impression in my soul
occurs through the Holy Spirit, and that consequently I am
bound to follow it. If I do not know this, my confidence,
great as it may be, is without the least foundation, and all the
light with which I perceive myself illumined, is but enthusi
asm. For whether the proposition supposed to be revealed,
be evidently true in itself, or visibly probable, or whether it
be difficult to vindicate it by the ordinary paths of knowledge,
this must nevertheless before all things be clearly established
and proved, that God has revealed this proposition, and that
1 The German is " Credulitiit und Coufidentz." — TR.
m] ON HUMAN UNDERSTANDING 35
what I take as a revelation certainly comes of itself into my
mind, and is no illusion, which some one else has thrust in or
my own fancy has awakened. Until one has come this far,
all confidence that this revelation comes from God is a mere
conjecture, and all this light which dazzles one is nothing but
an ignis fatuus, which will unceasingly lead us into this circle :
This is a revelation because I firmly believe it; and I believe it
because it is a revelation.
It follows from this that those who imagine that they have
such revelations of this or that truth must be assured that it
is God who has revealed it to them. For to say, as they gen
erally do, that they know it by the light which it brings with
it, which shines and flashes in their souls, and which they
cannot resist, means only that it is a revelation because
they believe it certainly is one ; since all the light of which
they speak is nothing but a strong imagination which is firmly
fixed in their mind, and yet has riot the least ground that it is
a truth. For they must consider that to assume accepted
grounds as reasonable and as a proof that it is a truth, is a nec
essary acknowledgment that they have no such (grounds).1
Because, if they have such, they receive this truth no longer
as a revelation, but as a truth established upon common
grounds. And if they believe it to be true, because it is no
revelation, and if they have no other reason to prove it a
revelation than simply because they are completely persuaded
of its truth, without any other ground and only on account of
this fancy, then they believe it to be a revelation only be
cause they strongly believe it to be a revelation. Who does
not see that if we build upon such grounds, we make our own
'fancy the only rule of our opinions arid conduct, and conse
quently subject ourselves to the strangest errors and vexa
tions. For once for all the strength of our opinions is no
proof of their correctness. Meanwhile men can approve an
error as a truth, as may be seen in the case of those zealous
people who maintain in the sharpest manner two propositions
contrary to one another.
In reference to which Locke well says, that if the light,
1 The text is: "Denn dieses miissen sie vor raisonable und von einigem
Beweise halten, der da zeige, dass es eine Warheit sey, genommene Griinde
annehmen, dass sie erkeunen miissen, wie sie dergleichen niclit habeu." — TR.
36 LEIBNITZ'S CRITIQUE OF LOCKE [m
which every one thinks he has in himself, and which in this
case is nothing but the strength of his own opinion, be a proof
that his thought comes from God, then we must conclude that
all contrary opinions have the right to pass as divine inspira
tions ; and God would be not only the father of light, but also
of wholly opposite lights, which lead men in ways wholly
contrary.
Therefore Locke concludes that he who does not wish to
fall into a mass of disorderly delusions and errors must first
test thoroughly this inner light which offers itself as a guide.
God, he says, does not destroy the man when he makes a
prophet. He leaves all his faculties in their natural condi
tion, so that he may thereby judge whether the inspirations
which he feels within have sprung from God or not. If God
will have us acknowledge the truth of a proposition, he permits
us to see this truth either through the ordinary paths of nat
ural reason, or he makes us know that it is a truth which we
must receive upon his authority, while he convinces us by
certain marks which reason cannot reject that it comes from
him. I will not, however, Locke adds, say by this, that we are
to examine by reason whether a proposition thus revealed to
us by God may be proved by natural principles, and if not we
may reject it; but I will say, that we must consult reason and
by its aid see whether it be a revelation from God or no.
For if reason finds it to be a divine revelation, it declares for
it as such from that hour on as well as for any other truth,
and makes it one of its rules, so that it cannot be rejected.
If this inner light, or a proposition which presents itself in
our mind as revealed, accords with the principles of reason or
with the word of God which is an attested revelation, we have
the. warrant of reason for it, and may accept this light as true,
and direct our faith and walk accordingly. If, however, this
light has the witness or proof of neither of these rules, we
cannot consider it as a revelation ; nay more, as a truth. For
if we at the same time believe it to be a revelation, that does
not, however, make it so ; it may, however, be shown by some
other mark to be really a revelation. The old prophets, when
they were to receive revelations from God, had other proof
than the inner light which assured them that these revelations
really came from God. They imagined not only that their
m] ON HUMAN UNDERSTANDING 37
imaginations came from God, but they had also external signs
which convinced them that God was the author of their reve
lation. And if they were to convince others of the same, they
received beforehand a special power to set forth the truth of
the commission given them of Heaven with visible signs. Thus
Moses saw a burning bush which was yet not consumed and
heard a voice out of the bush. This was something more than
an inner feeling of an impulse to free the children of Israel
from the hands of Pharaoh. Yet, Moses did not believe that
this was enough to warrant him in going into Egypt with God's
commission ; until God assured him by still another miracle, of
the rod changed into a serpent, that such was his real will, and
granted him the power to work precisely similar wonders in
the sight of Pharaoh. Precisely similar was it in Gideon's
case. These and other examples of the old prophets show
sufficiently that they did not believe that an inner vision or
their own imagination attested by no other affirmation a suffi
cient evidence that their imagination came from God ; although
the Scripture does not everywhere mention that they always
asked for or received such proofs.
These few passages from the clever work of Locke, under
the guidance of the accurate translator Coste, we have brought
forward as specimens. Perhaps we shall have further oppor
tunity to speak of it, when the Latin translation, with which
some one l is now occupied in England, is published.
In the " Monatliche Auszug " of the year 1701 is found (pp.
73-75) the following addition to the foregoing sketch : —
What Locke says of the connection and accompaniment of
ideas is not to be despised, and serves often to arouse the emo
tions; as for errors and false judgments, however, they spring
from other contiguous and peculiar causes, viz.: that one
assumes false principles, and imagines that he once had proof of
them in his mind, within which now a lapse of memory occurs ;
and then from incorrect conclusions which he produces from
these principles assumed as known, because he gives not the
time and labor to investigate all in a formal and orderly way.
1 Burridge of Dublin. The version appeared in 1701. — TR.
38 LEIBNITZ'S CRITIQUE OF LOCKE [m
Meanwhile it is true that the emotions greatly assist this credu
lity concerning principles and carelessness in false deduction ;
for one believes and easily draws the conclusion he would gladly
have. It is besides noticeable in this book of Locke's, that in
his last writings against the Rev. Lord Bishop Stillingfteet he
has changed a large part of his opinions concerning the nature
of the body contained in this Tentamen or Essay on Human
Understanding; while in this Tentamen he held opinions, in
common with modern philosophers, especially the followers
of Descartes and Gassendi, that in the body nothing is to be
met with but size, solidity or impenetrability, and motion or
change ; now, however, he begins to hold the opinion that there
is something to be found therein not revealed through these
qualities. He repudiates, besides, in this essay innate ideas
and the natural light, but appears not to distinguish suffi
ciently the necessary truths arising from possibility, from those
others whose ground must be assumed from the experience of
realities, and thus must be drawn from without.
Thus he accepts the tabula rasa of Aristotle, rather than
the implanted (ideas) of Plato. It is true that we do not
come upon thoughts in these most abstract matters, without
external sensations, but in the case of these necessary truths,
such sensations serve more as a reminder than as a proof ;
which (proof) must come simply and solely from internal
grounds, as those do not sufficiently understand who deal little
v?> demonstration proper.
NEW ESSAYS ON THE UNDERSTANDING
Bv THE AUTHOR OF THE SYSTEM OF PRE-ESTABLISHED
HARMONY
PREFACE
THE Essay on the Understanding, by a distinguished English
man, being one of the most beautiful and esteemed works of
this period, I have resolved to make some remarks upon it,
because having sufficiently meditated for a long time upon
the same subject and upon the greater part of the matters
therein touched upon, I have thought that it would be a
favorable opportunity to publish something under the title of
" Xew Essays on the Understanding," and to procure a favor
able reception to my thoughts, by putting them in so good
company. I l have thought also that I could profit from the
labor of another not only to lessen my own (since in fact it
is less difficult to follow the thread of a good author than to
work wholly independently), but further to add something to
what he has given us, which is always easier than to start from
the beginning ; for I think I have cleared up some difficulties
which he had left in their entirety, Thus his reputation is an
advantage to me ; having for the rest a disposition to render
justice, and very far from wishing to diminish the esteem in
which this work is held, I would increase it, if my approval
carried any weight. It is true I often differ in my views (from
1 Gerhardt's text reads as follows: "J'ai cru encor pouvoir profiler du
travail d'autruy non seulement pour diminuer le mien (puisqu'eii effect il y a
moins de peine a suivre le fil d'un bon atiteur qu'a travailler a nouveaux frais
en tout), mais encor pour adjouter quelque chose a ce qu'il nous a donne, ce
qui est tousjours plus facile que de commencer; car je crois d'avoir leve
quelques difficultes qu'il avoit laissees en leur entier. Ainsi sa reputation
m'est avantagnese ; estant d'ailleurs d'humeur a rendre justice et bien loin de
vouloir diminuer 1'estime qu'on a pour cet ouvrage, je 1'accroistrois, si raon
approbation estoit de quelque poids. II est vray que je suis souvent d'un autre
avis, mais bien loin de disconvenir du merite des Ecrivains celebres, on leur
rend temoignafre, en faisant counoistre en quoy et pour quoy on s'eloigne de
leur sentiment, quand on ju.^e necessaire d'empecher que leur autorite ne
prevaille a la raison en quelques points de consequence, outre qu'en satisfaisant
a de si excellens hommes. on rend la verite plus recevable, et il faut supposer
que c'est principalement pour elle qu'ils travaillent." — TR.
41
42 LEIBNITZ'S CRITIQUE OF LOCKE
him1), but very far from denying the merit of celebrated
writers, we bear witness to it, by making known in what and
why we differ from their views, when we judge it necessary
to prevent their authority from prevailing over reason on some
important points ; besides, by satisfying such excellent men,
we render the truth more acceptable, and it must be supposed
that it is principally for truth that they labor.
In fact, although the author of the Essay says a thousand
beautiful things which I commend, our systems are very dif
ferent. His has more relation to Aristotle, mine to Plato,
although we both differ in many things from the doctrine of
these two ancient philosophers. He is more popular, and I
am compelled sometimes to be a little more acroamatic and
more abstract, which is not an advantage to me, especially
when writing in a living language. I think, nevertheless, that
by making two persons speak, one of whom sets forth the
views drawn from the Essay of this author, and the other
joins thereto my observations, the parallel will be more to the
liking of the reader than wholly dry remarks, the reading of
which would be interrupted at every moment by the necessity
of recurring to his book in order to understand mine. It will
nevertheless be well still to compare sometimes our writings,
and not to judge of his views except by his own work, although
I have ordinarily preserved its expressions. It is true that the
constraint, which another's discourse, whose thread must be
followed, gives in making remarks, has prevented me from
thinking to secure the charms of which the dialogue is sus
ceptible ; but I hope the matter will make amends for the
defects of the style.
Our differences are upon subjects2 of some importance. The
question is to know whether the soul in itself is entirely empty
as the tablets upon which as yet nothing has been written
(tabula rasa) according to Aristotle, and the author of the
Essay, and whether all that is traced thereon comes solely
from the senses and from experience ; or whether the soul con
tains originally the principles of many ideas and doctrines
which external objects merely call up on occasion, as I believe
1 Erdmann and Jacques read : " que lui," which does not occur in Gerhardt's
text. — TR.
2 Erdmann and Jacques read : " objects." — TR.
ON HUMAN UNDERSTANDING 43
with Plato, and even with the schoolmen, and with all those
who interpret in this way the passage of St. Paul (Rom. 2 : 15)
where he states that the law of God is written in the heart.
The Stoics call these principles l prolepses, i.e. fundamental
assumptions, or what is taken for granted in advance. The
Mathematicians call them general notions (KOLVOJ. Iwouu). Mod
ern philosophers give them other beautiful names, and Julius
Scaliger in particular named them semina ceternitatis, also
zopyra, i.e. living fires, luminous flashes, concealed within us,
but which the encounter of the senses makes appear like the
sparks which the blow makes spring from the steel. And
the belief is not without reason, that these glitterings indicate
something divine and eternal which appears especially in the
necessary truths. Whence another question arises, whether
all truths depend upon experience, i.e. upon induction and
examples, or whether there are some which have still another
foundation. For if some events can be foreseen prior to any
proof which may have been made of them, it is manifest
that we ourselves contribute something thereto. The senses,
although necessary for all our actual knowledge, are not suffi
cient to give it all to us, since the senses never give us anything
but examples, i.e. particular or individual truths. Xow all the
examples which confirm a general truth, whatever their num
ber, do not suffice to establish the universal necessity of that
same truth, for it does not follow that what has happened will
happen in the same way. For example, the Greeks and the
Romans, and all the other peoples of the earth known to the
ancients, have always observed that before the lapse of twenty-
four hours day changes into night, and night into day. But
we would be deceived, if we believed that the same law holds
good everywhere else; for since then, the contrary has been
experienced in the region of Nova Zembla. And he would
still be in error who believed that, in our climates at least, this
is a necessary and eternal truth, which will always endure,
since we must think that the earth, and the sun even, do not
necessarily exist, and that there will perhaps be a time when
this beautiful star, together with its whole system, will not
longer exist, at least in its present form. Whence it appears
1 For a very full nomenclature of these principles, see Hamilton's Reid,
Note A., § V., Vol. II., pp. 755-770. 8th ed., Edinburgh and London, 1880. — TR.
44 LEIBNITZ'S CRITIQUE OF LOCKE
that necessary truths such as are found in pure mathematics,
and particularly in arithmetic and in geometry, must have
principles whose proof does not depend upon examples, nor
consequently upon the testimony of the senses, although with
out the senses it would never have occurred to us to think of
them. This distinction must be carefully made, and was so
well understood by Euclid, that he often proved by the reason,
what is sufficiently seen through experience and by sensible
images. Logic also, together with metaphysics and ethics, one
of which shapes theology and the other jurisprudence, both
natural (sciences), are full of such truths, and consequently
their proof can come only from internal principles which are
called innate. It is true that we must not imagine that these
eternal laws of the reason can be read in the soul as in an open
book, as the praetors edict is read upon his album without diffi
culty and research ; but it is sufficient that they can be discov
ered in us by dint of attention, for which the senses furnish
occasions, and successful experience serves to confirm reason,
in much the same way as proofs in arithmetic serve for the
better avoidance of error in calculating when the reasoning
is long. Herein, also, human knowledge differs from that
of the brutes : the brutes are purely empirics and only guide
themselves by examples ; for, so far as we can judge of them,
they never attain to the formation of necessary propositions ;
while men are capable of demonstrative sciences. It is also
for this reason that the faculty the brutes have for making
consecutions is something inferior to the reason of man. The
consecutions of the brutes are merely like those of simple
empirics, who claim that what has sometimes happened will
happen again in a case where something strikes them as similar,
without being able to judge whether the same reasons hold
good. This is why it is so easy for men to entrap the brutes,
and so easy for simple empirics to make mistakes. This is
why persons who have become skilful through age and experi
ence are not exempt (from error) when they depend too much
upon their past experience, as has happened to many in civil
and military affairs ; because they do not consider sufficiently
that the world changes, and that men become more skilful by
finding a thousand new dexterities, while the deer and hares
of the present do not become more cunning than those of the
ON HUMAN UNDERSTANDING 45
past. The consecutions of the brutes are only a shadow of
reasoning, i.e. are only connections of the imagination and
passages from one image to another, because in a new juncture
which appears similar to the preceding they expect anew that
connection which they formerly met with, as if things were
united in fact because their images are united in the memory.
It is true that reason also counsels us to expect ordinarily to see
that happen in the future which is conformed to a long past »
experience, but it is not on this account a necessary and iiifalli- 1
ble truth, and success may cease when least expected, when
the reasons change which have sustained it. Therefore the
wisest men do not so commit themselves to it as not to try to
discover, if possible, something of the reason of this fact in
order to judge when it is necessary to make exceptions. For
reason is alone capable of establishing sure rules, and supply
ing what is wanting to those which were not such by inserting
their exceptions ; and of finding at length certain connections
in the force of necessary consequences, which often furnish
the means of foreseeing the result without the necessity of
experiencing the sense-connections of images, to which the
brutes are reduced, so that that which justifies the internal
principles of necessary truths also distinguishes man from the
brutes.
Perhaps our clever author will not wholly differ from my
view. For after having employed the whole of his first book
in rejecting innate intelligence, taken in a certain sense, he
nevertheless, at the beginning of the second and in the sequel,
admits that ideas, which do not originate in sensation, come
from reflection. Now reflection is nothing else than attention
to what is in us, and the senses do not give us what we already
carry with us. That being so, can it be denied that there is
much that is innate in our mind, since we are innate, so to
speak, in ourselves ? and that there is in us : being, unity,
substance, duration, change, action, perception, pleasure, and
a thousand other objects of our intellectual ideas ? And these
objects being immediate to our understanding and always pres
ent (although they cannot always be perceived by reason of
our distractions and needs), what wonder that we say that these
ideas with all depending upon them are innate in us ? I have
made use also of the comparison of a block of marble which
46 LEIBNITZ'S CRITIQUE OF LOCKE
has veins, rather than of a block of marble wholly even, or of
blank tablets, i.e. of what is called among philosophers a tabula
rasa. For if the soul resembled these blank tablets, truths
would be in us as the figure of Hercules is in the marble, when
the marble is w_holly indifferent to the reception of this figure
or some other. But if tFere were veins in the block which
should indicate the figure of Hercules rather than other fig
ures, this block would be more determined thereto, and Her
cules would be in it as in some sense innate, although it would
be needful to labor to discover these veins, to clear them by
polishing, and by cutting away what prevents them from ap
pearing. Thus it is that ideas and truths are for us innate, as
inclinations, dispositions, habits, or natural potentialities, and
not as actions ; although these potentialities are always accom
panied by some actions, often insensible, which correspond to
them.
It seems that our clever author claims that there is nothing
virtual in us, and indeed nothing of which we are not always
actually conscious ; but he cannot take this rigorously, other
wise his opinion would be too paradoxical ; since, moreover,
acquired habits and the stores of our memory are not always
perceived and do not even always come to our aid at need,
although we often easily recall them to the mind upon some
slight occasion which makes us remember them, just as we
need only the beginning of a song to remember it.1 He limits
his thesis also in other places, by saying that there is nothing
in us of which we have not at least formerly been conscious.
f But besides the fact that no one can be assured by reason
; alone how far our past apperceptions, which Ave may have for
gotten, may have gone, especially according to the Platonic
doctrine of reminiscence which, wholly fabulous as it is, is in
no respect incompatible at least in part with reason wholly
pure : besides this, I say, why must we acquire all through
the perception of external things, and nothing be unearthed in
ourselves ? Is our soul then by itself such a blank that besides
the images borrowed from without, it is nothing ? This is not
an opinion (I am sure) that our judicious author could approve.
1 Erdmann and Jacques read : " le commencement d'une chanson pour nous
faire ressouvenir du reste," i.e. the beginning of a song to remind us of the
rest.— TR.
ON HUMAN UNDERSTANDING 47
And where do we find tablets that have no variety in them
selves ? For we never see a plane perfectly even and uniform.
Why, then, could we not furnish also ourselves with something
of thought from our own depths if we should dig therein?
Thus I am led to believe that at bottom his opinion upon this
point is not different from mine, or rather from the common
view, inasmuch as he recognizes two sources of our knowledge, ,
the Senses and Reflection.
I do not know whether it will be so 'easy to harmonize
him with us and with the Cartesians, when he maintains
that the mind does not always think, and particularly that
it is without perception when we sleep without dreaming;
and he objects x that since bodies can exist without motion,
souls can also exist without thought. But here I make
a somewhat different reply than is customary, for I hold
that naturally a substance cannot exist without action, and that
there is indeed never a body without movement. Experience
already favors me, and you have only to consult the book of
the distinguished Mr. Boyle against absolute rest, to be con
vinced of it ; but I believe reason favors it also, and this is one
of the proofs I have for doing away with atoms.
Moreover, there are a thousand indications which make us
think that there are at every moment an infinite number of — .-
perceptions in us, but without apperception and reflection, i.e. \
changes in the soul itself of which we are not conscious, be- -
cause the impressions are either too slight and too great in
number, or too even, so that they have nothing sufficiently
distinguishing them from each other; but joined to others,
they do not fail to produce their effect and to make themselves
felt at least confusedly in the mass. Thus it is that habit
makes us take no notice of the motion of a mill or a waterfall
when we have lived quite near it for some time. It is not
that the motion does not always strike our organs, and that
something no longer enters into the soul corresponding
thereto, in virtue of the harmony of the soul and the body,
but these impressions which are in the soul and the body, be
ing destitute of the attractions of novelty, are not strong
enough to attract our attention and our memory, attached to
objects more engrossing. For all attention requires memory,
1 Erdmann and Jacques read: " II dit que," i.e. He says that. — TR.
48 LEIBNITZ'S CRITIQUE OF LOCKE
and often when we are not admonished, so to speak, and
warned to take note of some of our own present perceptions,
we allow them to pass without reflection, and even without
being noticed ; but if any one directs our attention to them
immediately after, and makes us notice, for example, some
noise which was just heard, we remember it, and are conscious
\ of having had at the time some feeling of it. Thus there
were perceptions of which we were not conscious at once, con
sciousness arising in this case only from the warning after
some interval, however small it may be. And to judge still
better of the minute perceptions which wre cannot distinguish
in the crowd, I am wont to make use of the example of the
roar or noise of the sea which strikes one when on its shore.
To understand this noise as it is made, it would be necessary
to hear the parts which compose this whole, i.e. the noise of
each wave, although each of these little noises makes itself
known only in the confused collection of all the others, i.e. in
the roar itself, and would not be noticed if the wave which
makes it were alone. For it must be that we are affected a
little by the motion of this wave, and that we have some per
ception of each one of these noises, small as they are ; other
wise we would not have that of a hundred thousand waves,
since a hundred thousand nothings cannot make something.
One never sleeps so soundly as not to have some feeble and
confused sensation, and one would never be awakened by the
greatest noise in the world if he did not have some perception
of its small beginning; just as one would never break a rope
by the greatest effort in the world if it were not stretched
and lengthened a little by smaller efforts, although the slight
extension they produce is not apparent.
These minute perceptions are, then, of greater efficacy in
their results than one supposes. They form I know not what,
these tastes, these images of the sense-qualities, clear in the
mass, but confused in the parts, these impressions which sur
rounding bodies make upon us, which involve the infinite, this
connection which each being has with all the rest of the uni
verse. We may even say that in consequence of these minute
perceptions, the present is big with the future and laden with
the past, that all things conspire (o-v/ATn/oio. Trai/ra, as Hip
pocrates said), and that in the least of substances eyes as
ON HUMAN UNDERSTANDING 49
penetrating as those of God could read the whole course of
the things in the universe.
Quse sint, quse fuerint, quae mox futura trahantur.1
These insensible perceptions indicate also and constitute the
same individual who is characterized by the traces or expres
sions which they conserve of preceding states of this individual,
in making the connection with his present state ; and they can be
known by a superior mind, even if this individual himself should
not be awar&jQJ: them, i.e. when there would no longer be in him
the Express recollection of them. But they (these perceptions,
1 say) furnish, indeed, the means of finding again this recollec
tion at need by the periodic developments which may some day
happen. It is for this reason that death can be only a sleep, and
cannot, indeed, continue, the perceptions ceasing merely to be
sufficiently distinguished, and being reduced in the animals to a
state of confusion which suspends consciousness, but which can
not last always ; not to speak2 here of man, who must have in
this regard great privileges in order to preserve his personality.
It is also by means of the insensible perceptions that this
admirable pre-established harmony of the soul and the body,
and indeed of all the monads or simple substances, is ex
plained ; 3 which supplies the place of the unmaintainable
influence of one upon the others, and which in the judgment
of the author of the most excellent of dictionaries exalts the
grandeur of the divine perceptions beyond what has ever been
conceived. After this I would add little if I should say that
it • is these minute perceptions which determine us in many
junctures without being thought of, and which deceive the
vulgar by the appearance of an indifference of equilibrium, as
if we were entirely indifferent whether we turned (for ex
ample) to the right or to the left. It is not needful also that
I notice here, as I have done in the book itself, that they
cause that uneasiness which I show to consist in something
which differs from pain only as the small from the great, and
which, however, often constitutes our desire and even our
1 Erdmann reads : quse mox, etc. ; Jacques : quse, mox ventura trahantur.
Gerhardt's reading: " que " is evidently an error. — TR.
2 Erdmann and Jacques omit: "pour ne parler icy de 1'homme qui doit
avoir en cela des grands privileges pour garder sa personalite'." — TR.
3 Erdmann and Jacques read " j'explique," I explain. — TR.
E
50 LEIBNITZ'S CRITIQUE OF LOCKE
pleasure by giving to it an exciting flavor. It is also l the
insensible parts of our sensible perceptions, .which produce
a relation between the perceptions of colors, heat, and other
sensible qualities, and between the motions in bodies which
correspond to them ; while the Cartesians together with
our author, penetrating as he is, conceive the perceptions
which we have of these qualities as arbitrary, i.e. as if God
had given them to the soul according to his good pleasure,
without any regard to any essential relation between .these
perceptions and their objects : a view which surprises me
and which appears to me little worthy of the wisdom of
the Author of things, who does nothing without harmony and
without reason.
In a word, the insensible perceptions are as eminently use
ful in Pneumatology 2 as are the insensible corpuscles in
Physics, and it is equally unreasonable to reject the one or
the other under the pretext that they are out of reach of our
senses. Nothing is accomplished all at once, and it is one of
my great maxims, and one of the most verified, that nature
mcikesjio leaps : a maxim which I called the Laiv of Continuity,
when I spoke of it in the first "Xouvelles de la Republique
des Lettres," 3 and the use of this law is very considerable in
Physics. This law declares that we pass always from the small
to the great, and the reverse, through the medium, in degree as
in parts, and that motion never springs immediately from rest,
nor is reduced thereto save by a smaller motion, as one never
completes the survey of any line or length until he has com
pleted a smaller line, although hitherto those who have set
forth the laws of motion have not observed this law, believing
that a body can receive in a moment a motion contrary to the
preceding. And all this makes one indeed think that the
1 Erclmann and Jacques read : " Ce sont les memes parties insensibles," etc.,
It is the same insensible parts, etc. — TR.
2 I.e. Psychology. Cf. Hamilton's Reid, 8th ed., Vol. I., p. 217 a, and note.
— TR.
3 A literary journal published by Pierre Bayle at Amsterdam, 1084-1687 ;
afterwards continued, at Bayle's request, by Basnage, under the title " Histoire
de ouvra^es des Savants," 1687-1709. Leibnitz published in this journal in
July, 1698, his Eclair cissement des difficultes que M. Bayle a trouv^es dans le
si/steme nouveau de V union de I'dme et du corps. Gerhardt, Vol. 4, pp. 517-
524; Erdmann, pp. 150-154; Jacques, Vol. 1, pp. 481-487. Translation, Appen
dix, pp. . 706-712. — TR.
ON HUMAN UNDERSTANDING 51
noticeable perceptions also arise by degrees from those which
are too minute to be observed. To think otherwise, is to have
little knowledge of the immense subtilty of things which ~\
always and everywhere surrounds an actual infinite.
I have also noticed that in virtue of these insensible varia
tions, two individual things cannot be perfectly alike, and
that they must always differ more than niunero: a fact which
destroys the blank tablets of the soul, a soul without thought,
a substance without action, a vacuum in space, atoms and even
particles not actually divided in matter, absolute rest, entire
uniformity in one portion of time, place, or matter, perfect
globes of the second element, born of cubes perfect and orig
inal, and a thousand other fictions of philosophers which arise
from their incomplete notions, and which the nature of things
does not allow, and which our ignorance and the little atten
tion we give to the insensible let pass, but which cannot be
made tolerable unless they are limited to the abstractions of
the mind which protests that it does not deny what it puts
aside, and thinks should not enter into any present considera
tion. Otherwise if it were very well understood, viz. : that
things of which we are not conscious are neither in the soul
nor the body, we should be lacking in philosophy as in politics,
in neglecting TO ^iKpov, the insensible progressions, while an
abstraction is not an error, provided we know what it is that
we feign therein. Just as the mathematicians employ it when
they speak of the perfect lines which they propose to us, of
uniform motions and of other regulated effects, although matter
(i.e. the medley of the effects of the surrounding infinite) always
makes some exception. It is for the sake of distinguishing the
considerations and of reducing so far as we may do so the effects
to reasons, and of foreseeing some of their consequences, that
we proceed thus. For the more we are careful to neglect no
consideration that we can regulate, the more practice corre
sponds to theory. But it belongs only to the supreme Reason,
whom nothing escapes, distinctly to comprehend all the infinite
and to see all the reasons and all the consequences. All that
we can do in regard to infinites is to know them confusedly,
and to know at least distinctly that they are such ; otherwise
we judge very wrongly of the beauty and the grandeur of the
universe ; so also we could not have a sound Physics explaining
52 LEIBNITZ'S CRITIQUE OF LOCKE
the nature of bodies in general, and still less a proper Pneunia-
tology comprising the knowledge of God, of souls, and of simple
substances in general.
This knowledge of insensible perceptions serves also to
explain why and how two souls, human or otherwise,1 of one
and the same species never come forth perfectly alike from
the hands of the Creator and haye always each its original
relation to the points of view which it will have in the uni
verse. But this it is which already follows from the remarks
f I have made about two individuals, viz. : that their difference
i -is always more than numerical. There is, moreover, another
point of importance, in respect to which I am obliged to devi
ate not only from the opinions of our author, but also from
those of the majority of modern philosophers : I believe with
the majority of the ancients that all genii,2 all souls, all simple
created substances, are always joined to a body, and that there
are never souls entirely separated. I have a priori reasons for
my view ; but the doctrine will be found to have this advan
tage, that it resolves all the philosophical difficulties as to the
condition of souls, their perpetual conservation, their immor
tality, and their operation. The difference between one of
their states and another, never being and never having been
other than that of more sensible to less sensible, of more
perfect to less perfect, or the reverse, this doctrine renders
their past or future state as explicable as that of the present.
One feels sufficiently, however little reflection he makes, that
rthis is rational, and that a leap from one state to another
infinitely different could not be natural. I am astonished
that by leaving the natural without reason, the schoolmen
have been willing purposely to plunge themselves into very
great difficulties, and to supply matter for apparent triumphs
of the strong-minded, all of whose reasons fall at once by this
explanation of things, in which there is no more difficulty in
conceiving the conservation of souls (or rather, according to
my view, of the animal) than there is in conceiving the change
of the caterpillar into the butterfly, and the conservation of
thought in sleep, to which Jesus Christ has divinely well com
pared death. I have already said also that sleep could not
1 Erdmann reads : " on deux o-hos^s," or two things. — TR.
2 I.e. Angels and archangels. — TR.
ON HUMAN UNDERSTANDING
last always, and it will last least or almost not at all in the
case of rational souls who are always destined to preserve the
personality which has been given them in. the City of God,
and consequently remembrance : and this in order to be more
susceptible of chastisements and recompenses. And I add
further that in general no derangement of the visible organs
is capable of throwing things into entire confusion in the
animal or of destroying all the organs and depriving the soul
of all its organic body and of the ineffaceable remains of all
preceding traces. But the ease with which the ancient doc
trine of subtile bodies connecte'd with the angels (which was
confounded with the corporeality of the angels themselves)
has been abandoned, and the introduction of pretended sepa
rate intelligences in creatures (to which those who make the
heavens of Aristotle revolve have contributed much), and
finally the poorly understood view into which we have fallen,
that the souls of brutes could not be preserved without falling
into metempsychosis, and1 without conducting them from body
to body, and the perplexity into which men have fallen by
their ignorance of what to do with them, have caused us, in
iny opinion, to neglect the natural explanation of the conserva
tion of the soul. This has done much harm to natural relig-
.ion, and has caused many to believe that our immortality
was only a miraculous grace of God, of which also our cele
brated author speaks with some hesitation, as I shall presently
remark. But it would be well had all those who are of this
opinion spoken as wisely and in as good faith as he, for it is to
be feared that many who speak of immortality as a grace do
so only to keep up appearances, and resemble at bottom these
Averroists and some bad Quietists who picture to themselves
an absorption and the reunion of the soul with the ocean
of divinity : a notion whose impossibility my system alone
perhaps evinces.
It seems also that we differ further in regard to matter, in
that the author thinks that a vacuum is necessary to motion,
because he thinks that the minute parts of matter are rigid.
And I admit that if matter were composed of such parts,
1 Gerhardt's text is: "et sans les promener de corps en corps, et 1'embar-
ras ou 1'on a este' en ne sachant ce qu'on en devoit faire." Erdmann and
Jacques omit the clause. — TR.
54 LEIBNITZ'S CRITIQUE OF LOCKE
motion in a plenum would be impossible, as if a room were
full of a quantity of little pebbles without there being the
least empty space. But this supposition, for which there
appears also to be no reason, is not admissible, although this
learned author goes as far as to believe that rigidity or cohe
sion of the minute parts makes the essence of the body. It is
necessary rather to conceive space as full of a matter origi
nally fluid, susceptible of all the divisions, and even actually
subject to divisions and subdivisions to infinity, but with
this difference, however, that it is divisible and divided un
equally in different parts on account of the motions which
more or less concur there. This it is which causes matter to
have everywhere a degree of rigidity as well as of fluidity, and
no body to be hard or fluid in the highest degree, i.e. no atom
to be found of an insurmountable hardness nor any mass
entirely indifferent to division. The order, also, of nature, and
particularly the law of continuity, destroy equally the one and
the other.
I have also shown that cohesion, which by itself would not
be the effect of impulse or of motion, would cause a traction,
taken strictly. For if there were a body originally rigid, — for
example, an Epicurean atom, — which should have a part pro
jecting like a hook (since we can imagine atoms of all sorts of
shapes), this hook pushed would draw with it the rest of this
atom ; i.e. the part which is not pushed, and which does not
fall in the line of the impulsion. Our learned author, how
ever, is for himself opposed to these philosophic tractions,
such as were formerly attributed to the abhorrence of a
vacuum, and he reduces them to impulsions, maintaining with,
the moderns that one part of matter works immediately upon
another only by pushing it by contact, in which I think they
are right, because otherwise there is nothing intelligible in the
operation.
I must not, however, conceal the fact that I have noticed a
sort of retraction by our excellent author on this subject,
whose modest sincerity I cannot forbear praising in this
respect as much as I have admired on other occasions his
penetrating genius. It is in his reply to the second letter of
the late Bishop of Worcester,1 printed in 1699, p. 408, where,
i Edward Stillingfleet, 1635-1699: Bishop of Worcester, 1G89-KJ99. — TR.
ON HUMAN UNDERSTANDING 55
in order to justify the view which he had maintained' against
this wise prelate, viz. : that matter might think, he says among
other things : " / admit that I said (Essay on Understanding,
Book II. chap. 8, § 11) that body ads by impulse and not
otherwise. This also teas my vieiv when I wrote it, and even now
I cannot conceive its action in any other way. Bat since then I
have been convinced by the judicious Mr. Newton's incomparable
book that there is too much presumption in wishing to limit the
power of God by our limited conceptions. ( The gravitation of
matter towards matter in ways inconceivable to me, is not only a
demonstration that God, when it seems to him good, can put into
bodies powers and modes of acting which are beyond tvhat can be
derived, from our idea of body or explained by tvhat we know of
matter ; but it is furthermore an incontestable instance that he has
really done so. I shall therefore take co.re to correct this passage
in the next edition of my book." l I find that in the French
version of this book, made undoubtedly from the latest edi
tions, the matter has been put thus in this § 11 : It is evident,
at least so far as we can conceive it, that it is by impulse and
not otherwise that bodies act on each other ; for it is impossible
for us to understand how the body can act upon icliat it does not
touch, which is the same as to imagine that it can act where it
is not.
I can only praise this modest piety of our celebrated author,
who recognizes that God can do more than we can understand,
and that thus there may be inconceivable mysteries in the
articles of faith ; but I should not wish to be obliged to recur
to the miracle in the ordinary course of nature and to admit
powers and operations absolutely inexplicable. Otherwise too
much license will be given poor philosophers, under cover of
what God can do, and by admitting these centripetal virtues or
these immediate attractions from afar without being able to
make them intelligible, I see nothing to hinder our Scholastics
from saying that everything is done simply by their faculties
and from maintaining their intentional species which proceed
I 1 have retranslated the passage from the French version, as given by Ger-
hardt. For the original, cf. Locke, Philos. Works (Bohn's ed.), Vol. II., p. 395.
The entire letter is found in Locke's Works, Vol. I., pp. 578-774; this particu
lar passage, p. 754. Edition of 4 vols., 4to. 7th ed., 1768. Printed for H. Wood-
fall, A. Millar, and others. — TR.
50 LEIBNITZ'S CRITIQUE OF LOCKE
from objects even to us and find means of entering even into
our souls. If that is so,
Omnia jam fient, fieri quse posse negabain.
So that it seems to me that our author, quite judicious as he
is, goes here a little too much from one extreme to the other.
He makes a difficulty in regard to the operations of souls when
the question is only of admitting what is not sensible, and
behold he gives to bodies what is not even intelligible; granting
them powers and actions which surpass in my view all that a
created 'spirit can do and understand, since he grants them
attraction, and that even at great distances without limiting
them to any sphere of activity, and .this in order to maintain a
view which does not appear less inexplicable, viz. : the possi
bility of the thought of matter in the natural order.
The question which he discusses with the celebrated Prelate
who attacked him, is, whether matter can think, and as it is an
important point even for the present work, I cannot refrain
from entering upon it a little and from taking note of their
controversy. I will give the substance of their discussion
upon this subject, and take the liberty of saying what I think
of it. The late Bishop of Worcester, fearing (but in my
opinion without good reason) lest our author's doctrine of ideas
might be liable to certain abuses prejudicial to the Christian
faith, undertook to examine some points in it in his "Vindication
of the Doctrine of the Trinity " ; l and having rendered justice
to this excellent writer, by recognizing that he thinks the exist
ence of spirit as certain as that of body, although one of these
substances is as little known as the other, he asks (p. 241 sq.)
how reflection can assure us of the existence of spirit, if God
can give to matter the power of thought according to the view
of our author, Book IV., chap. 3, since thus the way of ideas
which must serve to discern - what may suit the soul or the,-
body, would become useless ; while he had said in Book II. of
the Essay on Understanding, chap. 23, §§ 15, 27, 28, that the
operations of the soul furnish us the idea of mind and the
1 Published in the autumn of 1696. Cf. Alexander Campbell Fraser, Locke*
pp. 245-246 (Philosophical Classics), Edinburgh: Wm. Blackwood and Sons,
1890. — TR.
2 Gerhardt reads: "discerner"; Erdmaun and Jacques: "dis.cuter," to
discuss, debate, argue. — TR.
ON HUMAN UNDERSTANDING 57
understanding, and the will renders this idea as intelligible to
us as the nature of body is rendered intelligible to us by solid
ity and impulse. This is how our author replies in his first
letter (p. 65 sq.) : " I believe I have proved that there is a spirit
ual substance in us, for ice experience in ourselves thought. Now
this action or this mode cannot be the object of the idea of a thing
subsisting by itself, and consequently this mode needs a support, a
subject, in which it may inhere, and the idea of this support forms
what we call substance. . . . For since the general idea of sub
stance is everywhere the same, it follows that the modification,
which is called thought or power of thinking, being joined to it,
there results a mind without the necessity of considering what
other modification it has besides; i.e. whether it has solidity or
not. And, on the other hand, the substance ivhich has the modifi
cation called solidity will be matter, whether thought is joined to it
or not. Bat if by a spiritual substance you mean an immaterial
substance, I admit that I have not proved that there is one in us,
and that it cannot be demonstrably proved on my principles. Al
though what I have said on the systems of matter (Book IV.,
chap. 10, § 16) in proving that God is immaterial, renders it in
the highest degree probable, that the substance ivhich thinks in us
is immaterial. . . . However, I have shown [the author adds,
p. 68] that the great ends of religion and of morals are assured
by the immortality of the soul, without the need of supposing its
immateriality." l
The learned Bishop in his reply to this letter, in order to
make it evident that our author held another view, when he
wrote the second book of the Essay, quotes, p. 51, this passage
(taken from the same book, chap. 23, § 15), where it is said, that
by the simple ideas which we have deduced from the operations of
our mind, we can form the complex idea of a mind. And that
putting together the ideas of thought, of perception, of liberty, and
of power to move our body, we have as clear a notion of immate
rial substances as of material He quotes still other passages
to show that the author opposes mind to body. And he says
(p. 54) that the ends of religion and of morals are the better
1 1 have retranslated the passage from the French version as given by Ger-
hardt. For the original, cf. Locke, Philo*. Works (Bonn's ed.), Vol. II.,
p. 387. The entire letter is found in Locke's Works, Vol. L, pp. 458-517 ; this
particular passage, p. 477. Edition of 4 vols., 4to. 7th ed., 17(i8. Printed for
H. Woodfall, A.' Millar, and others. — TR.
58 LEIBNITZ'S CRITIQUE OF LOCKE
assured by proving that the soul is immortal by its nature, i.e.
immaterial. He quotes also (p. 70) this passage, that the ideas
ice have of particular and distinct kinds of substances are nothing
else than different combinations of simple ideas;1 and that thus
the author believed that the idea of thinking and of willing
gave another substance different from that which the idea of
solidity and of impulse gives, and that (§ 17) he remarks that
these ideas constitute the body as opposed to mind.
The Bishop of Worcester might add that from the fact that
the general idea of substance is in the body and in the mind,
it does not follow that their differences are modifications of one
and the same thing, as our author has just said in the part of
his first letter which I have quoted. It is necessary carefully
to distinguish between modifications and attributes. The
faculties of having perception and of acting, extension, solid
ity, are attributes or perpetual and principal predicates ; but
/thought, impetuosity, figures, movements, are modifications of
/_.,these attributes. Furthermore, we must distinguish between
physical (or, rather, real) genus and logical or ideal genus.
Things which are of the same physical genus, or which are
homogeneous, are of the same matter, so to speak, and may
often be changed the one into the other by the change of mod
ification, as circles and squares. But two heterogeneous things
may have a common logical genus, and then their differences
are not simple accidental modifications of one and the same
subject, or of one and the same metaphysical or physical mat
ter. Thus time and space are very heterogeneous things, and
we should do wrong to imagine I know not what real common
subject which had only the continuous quantity in general,
and whose modifications should cause the rise of time and
space.2 Some one will perhaps laugh at these distinctions of
the philosophers of two genera, the one merely logical, the
other real ; and of two matters, the one physical, viz. : that of
bodies, the other metaphysical only or general ; as if some one
said that two parts of space are of one and the same matter,
or that two hours are likewise among themselves of one and
1 Locke, Philos. Works (Bohri's ed.), Vol. 1, p. 426, chap. 23. § 0. — TR.
2 Erdmann and Jacques add : " Cependant leur genre logique commun est la
quantite' continue," i.e. Nevertheless their common logical genus is the con
tinuous quantity. — TR.
ON HUMAN UNDERSTANDING 59
the same matter. Nevertheless, these distinctions are not dis- ^
tinctions of terms merely, but of things themselves, and seem /
to come in here very opportunely, where their confusion has
given rise to a false conclusion. These two genera have a
common notion, and that of the real genus is common to the
two matters, so that their genealogy will be as follows : —
f Logical merely,- varied by simple differences.
~ f Metaphysical only, where
1 Eeal, whose differences are modi- \ there is homogeneity.
[ fications, i.e. Matter. 1 Physical, where there is a
[ solid homogeneous mass.
I have not seen the second letter of the author to the
Bishop, and the reply which this prelate makes to it scarcely
touches the point relating to the thinking of matter. But the
reply of our author to this second answer returns to it. God
(says he, nearly in these words, p. 397) adds to the essence of
matter the qualities and perfections which please him, simple
movement in some parts, but hi plants, vegetation, and in ani
mals, sentiency. Those w-ho agree up to this point, cry out as
soon as we go a step farther, and say that God can give to matter
thought, reason, will, as if this destroyed the essence of matter.
But to prove it, they allege that thought or reason is not included
in the essence of matter, a point of no consequence, since move
ment and life are not included therein either. They assert, also,
that ive cannot conceive of matter as thinking; but our conception
is not the measure of God's power.1 After this he cites the ex
ample of the attraction of matter (p. 99, but especially p. 408),
where he speaks of the gravitation of matter towards matter,
attributed to Mr. Newton, (in the terms which I have quoted
above), admitting that we can never conceive the manner of it.
This is in reality to return to the occult, or, what is nTore, in
explicable qualities. He adds (p. 401) that nothing is more
calculated to favor the sceptics than to deny what we do not
understand ; and (p. 402) that we do not conceive even how the
soul thinks. He will have it (p. 403) that, since the two sub-
1 For the original, cf. Locke. Philos. Works (Bonn's ed.), Vol. 2, pp. 390, 3JH.
The entire letter is found in Locke's Works, Vol.1, pp. 578-774; this particu
lar passage, pp. 74!), 750. Edition of 4 vols., 4to. 7th ed., 1768. Printed for
H. Woodfall, A. Miller, and others. — TR.
60 LEIBNITZ'S CRITIQUE OF LOCKE
stances, material and immaterial, are capable of being conceived
in their naked essence without any activity, it depends upon
God to give to each the power of thought. And he wishes to
take advantage of the admission of his opponent, who had
granted sentiency to the brutes, but who would not grant them
any immaterial substance. He claims that liberty, conscious
ness (p. 408), and the power of abstract thought (p. 409) can
be bestowed upon matter, not as matter, but as enriched b}^ a
divine power. Finally, he quotes (p. 434) the remark of a
traveller as eminent and judicious as M. de la Loubere,1 that
the pagans of the East acknowledge the immortality of the
soul without being able to comprehend its immateriality.
On all this I would remark, before coming to the explana
tion of my view, that it is certain that matter is as little capa
ble of mechanically producing feeling, as of producing reason,
as our author admits ; that in truth I acknowledge that it is
not permissible to deny what we do not understand, but I add
.(that we are right in denying (at least in the natural order)
what is absolutely neither intelligible nor explicable. I main
tain, also, that substances (material or immaterial) cannot be
conceived in their naked essence without any activity ; that
activity belongs to the essence of substance in general ; that,
finally, the conception of creatures is not the measure of God's
power, but .that their concept! vity, or power of conception, is
the measure of nature's power; all this is in harmony with
the natural order, being capable of being conceived or under
stood by some creature.
Those who understand my system will think that I cannot
wholly agree with the one or the other of these two excellent
authors, whose discussion, however, is very instructive. But
to explain myself distinctly, it is necessary before all things
to consider that the modifications which may belong naturally
or without miracle to a subject must come to it from the limi
tations or variations of a real genus, or of a constant and abso
lute original nature. Tor it is thus that Philosophers dis-
i La Loubere, Simon de, 1642-1729. Sent by Louis XIV. in 1687 to Siam,
to establish diplomatic and commercial relations between that kingdom and
France. While there he collected a large amount of exact and interesting
information concerning the country, its history, customs, religion, etc., which,
on his return, he published in his Du royaume de Siam, Paris, 1691; English
translation, London, 1693. — TR.
ON HUMAN UNDERSTANDING 61
tinguish the modes of an absolute being from that being itself ;
as it is known that size, figure, and movement are manifestly \
limitations and variations of corporeal nature. For it is clear
how a limited extension gives figures, and that the change
which is made in it is nothing but motion. And whenever
we find any quality in a subject, we must believe that if we
understood the nature of this subject and of this quality, we
should conceive ho\v this quality can result therefrom. Thus
in the order of nature (miracles aside) it is not optional with
God to give to substances indifferently such or such qualities,
and he will never give to them any, save those which will be
natural to them, i.e. which can be derived from their nature as
explicable modifications. Thus it may be asserted that matter
will not naturally possess the attraction mentioned above, and
will not proceed of itself in a curved line, because it is impossi
ble to conceive how this takes place there, i.e. to explain it
mechanically, while that which is natural must be capable of
becoming distinctly conceivable if we wrere admitted into the
secrets of things. This distinction between what is natural
and explicable and what is inexplicable and miraculous
removes all the difficulties, and by rejecting it, we should
maintain something worse than the occult qualities ; and in so
doing would renounce philosophy and reason, by opening
retreats for ignorance and idleness, though a dead system,
which admits not only that there are qualities which we do not
understand, of which there are only too many, but also that
there are some which the greatest mind, if God gave him every
possible opening, could not comprehend, i.e. which would be
either miraculous or without rhyme and reason ; and also that
God should work miracles ordinarily would be without rhyme
and reason, so that this hypothesis would destroy equally our
philosophy which seeks reasons, and the divine wisdom which
furnishes them.
Now as to thought, it is certain, and the author admits it
more than once, that it could not be an intelligible modifica
tion of nature or one which could be comprised therein and
explained, i.e. that a being who feels and thinks is not a mech
anism like a watch or a mill, so that we might conceive sizes,
figures, and movements, whose mechanical conjunction might
produce something thinking, and even feeling in a mass in
G2 LEIBNITZ'S CRITIQUE OF LOCKE
which there was nothing of the kind, which would cease also
in the same manner upon the derangement of this mechanism.
It is not then a natural thing for matter to feel and think, and
this can happen within it only in two ways, of which one will
be that God should unite with it a substance to which thought
is natural, and the other that God by a miracle should put
thought therein. In this, then, I am wholly of the opinion of
the Cartesians, except that I extend it even to the brutes,
and that I believe they have sentiency and (properly speak-
| ing) immaterial souls, and are as imperishable as the atoms of
Democritus or Gassendi, while the Cartesians, perplexed with
out reason by the souls of brutes, and not knowing what they
are to do with them if they are preserved (for want of having
thought of the conservation of the same animal reduced to
miniature), have been compelled to refuse even sentiency to the
animals against all appearances and contrary to the judgment
of the human race. But if any one should say that God at
least may add the faculty of thinking to the prepared mechan
ism, I should reply that if this were done, and if God added
this faculty to matter without putting therein at the same
h* time a substance which was the subject of inhesion of this
; same faculty (as I conceive it), i.e. without adding thereto an
immaterial soul, it would be necessary that matter should be
miraculously exalted in order to receive a power of which it is
naturally incapable ; as some scholastics l claim that God ex
alts lire even to the point of giving it the force to burn imme-.
diately spirits separated from matter, a thing which would be1
a miracle, pure and simple. And it is enough that it cannot
be maintained that matter thinks without putting into it an
imperishable soul, or a miracle, and that thus the immortality
of our souls follows from what is natural, since their extinc
tion can be maintained only by a miracle, whether by exalting
matter or by annihilating the soul. For we know well that
God's power can make our souls mortal, wholly immaterial
(or immortal by nature alone) as they may be, since he can
annihilate them.
Now this truth of the immateriality of the soul is undoubt-
1 Erdmann and Jacques read : " Quelques scholastiques ont pretendu quelque
chose d'approchant savoir," i.e. Some scholastics have claimed something
like this: viz. — TR.
ON IIUMAX UNDERSTANDING 63
edly of importance. For it is infinitely more advantageous to
religion and morality, especially in our times (when many
people hardly respect revelation alone and miracles ]), to show
that souls are immortal by nature, — and that it would be a mir
acle if they were not, — than to maintain that our souls ought
naturally to die, but that it is in virtue of a miraculous grace
grounded in the promise of God alone that they do not die.
Also for a long time it has been known that those who have
desired to destroy natural religion and to reduce all to revealed
religion, as if reason taught us nothing regarding it, have been
looked upon with suspicion ; and not always without reason.
But our author does not belong to that number. He maintains
the demonstration of the existence of God, and he attributes
to the immateriality of the soul a probability in the liighest de
gree, which could consequently pass for a moral certainty, so
that I think that, having as much sincerity as penetration, he
could easily accommodate himself to the doctrine which I have
just set forth, and which is fundamental in every rational phi
losophy. For otherwise I do not see how one can prevent him
self from falling back into the fanatical philosophy,'2 such as the
"Philosophia Mosaica" of Fludd,3 which saves all phenomena by
attributing them to God immediately and by miracle ; or into
the barbaric philosophy like that of certain philosophers and
physicians of the past, which still manifested the barbarity of
their age, and which to-day is with reason despised, who saved
appearances by forging purposely occult qualities or faculties
which they imagined to be like little demons or goblins capa
ble of producing without ceremony what is demanded, just as
if watches marked the hours \)y a certain horodeictic faculty
without needing wheels, or as if mills ground the grain by a
fractive faculty without needing anything resembling mill
stones. As to the difficulty that many people have had in
conceiving an immaterial substance, it will easily cease (at
least in good part) if they will not demand substances sepa
rated from matter, as in fact I do not believe there ever are any
naturally among creatures.
1 Erclmann and Jacques omit this clause. — TR.
2 Erdmann and Jacques read : "la philosophic ou fanatique," i.e. philosophy
or fanaticism. — TR.
3 Robert Fludd (1574-1037), an English physician and mystical philosopher.
The Philosophia Mosaica was published at Gouda in 1G88. — TR.
NEW ESSAYS ON HUMAN UNDERSTANDING
BOOK I. — IXNATE IDEAS
CHAPTER I1
ARE THERE IXXATE PRINCIPLES IX THE MIND OF MAX ?
Philaletlies. Having recrossed the sea after finishing my
business in England, I thought at once of paying you a visit,
sir, in order to cultivate our former friendship, and to con
verse upon matters which lie close to our hearts, and upon
which I believe I have acquired some new light during my
long stay in London. When we were living formerly quite
near each other at Amsterdam, we both took much pleasure
in making researches into the principles and means of pene
trating into the heart of things. Although our opinions often
differed, this diversity increased our satisfaction, when, in our
conference together, notwithstanding the contrariety which
sometimes existed, there mingled nothing disagreeable. You
were for Descartes 2 and for the opinions of the celebrated
author2 of "The Search after Truth," and I found the opinions
of Gassendi,2 cleared up by Bernier, easier and more natural.
Now I feel myself greatly strengthened by the excellent work
which an illustrious Englishman, with whom I have the honor
of a particular acquaintance, has since published, and which
has several times been reprinted in England, under the modest
1 Book I. of Locke's Essay has four chapters, of which chap. 1 is introduc
tory. Chap. 1 of Leihnitz corresponds to chap. 2 of Locke. — TR.
2 Rene' Descartes, 1596-1650 ; Nicolas Malebranehe, 1638-1715, his chief
work, De la Recherche de la Verite, 1674; Pierre Gassendi, 1592-1655, Abreye
de la Philosophic de Gassendi, 8 vols., 1678, 2d ed., 7 vols., 1684, by Francois
Bernier. — TR.
64
CH. i] ON HUMAN UNDERSTANDING 65
title of "An Essay concerning Human Understanding." And
I am delighted that it has appeared lately in Latin and in
French, in order that it'may be more generally useful. I have
greatly profited by the reading of this work, and indeed from
the conversation of the author, with whom I have talked
often in London, and sometimes at Gates, at the house of my
Lady Masham,1 worthy daughter of the celebrated Cudworth,2
a great English philosopher and theologian, author of the
Intellectual System, from whom she has inherited the spirit
of meditation and the love for good learning, which appeared
particularly in the friendship which she kept up with the
author of the Essay. And, as he had been attacked by some
clever Doctors, I took pleasure in reading also the defence
which a very wise and very intelligent young lady made for
him, besides those which he made for himself. This author
writes in the spirit of the system of Gassendi, which is at
bottom that of Democritus ; 2 he is for the vacuum and for
atoms ; he believes that matter might think ; that there are
no innate ideas, that our mind is a tabula rasa, and that we do
not always think; and he appears disposed to approve the
most of the objections which Gassendi has made3 to Descartes.
He has enriched and strengthened this system by a thousand
beautiful reflections ; and I do not at all doubt that now our
party will triumph boldly over its adversaries, the Peripa
tetics and the Cartesians. This is why, if you have not yet
read this book, I invite you to do so, and if you have read it,
I ask you to give me your opinion of it.
Tlieophilus. I rejoice to see you, on your return after a long
absence, happy in the conclusion of your important business,
full of health, steadfast in your friendship for me, and always
transported with an ardor equal to the search for the most
1 The correspondence between Leibnitz and Lady Masham is given in full
by frerhardt, Vol. 3, pp. 331 sq. — TR.
. 2 Ralph Cudwortli, 1617-1688, his principal work, The True Intellectual
System of the U inverse, London, 1678; Democritus, born probably about the
middle of the fifth century B.C., as he says (Diog. L., IX., 41) he was •" still
young when Anaxagoras," 500-428 B.C., "was already old (ceos Ka.-ra irpea&vTr\v
'Ava£a-y6pav)." . . . "The year of his death is unknown," Zeller, Outlines
of the History of Greek Philosophy, pp. 76, 77, New York: H. Holt & Co.,
1886.— TR.
3 In Vol. 3 of his Opera, of which two editions were published: by Mont-
mort, 1655, 6 vols. folio, Lyftiis ; by Averauius, 1727, also 6 vols. folio. — TR.
F
66 LEIBNITZ'S CRITIQUE OF LOCKE [BK. i
important truths. I no less have continued my meditations
in the same spirit, and I believe I have profited as much as,
and, not to flatter myself, perhaps more than yourself. In
deed, my need therein was greater than yours, for you were
more advanced than I. You were more conversant with spec
ulative philosophers, and I was more inclined towards ethics.
But I have learned more and more how ethics receives strength
from the solid principles of true philosophy ; therefore I have
lately studied these principles more diligently, and have begun
meditations quite new. So that we shall have the means of
giving ourselves a reciprocal pleasure of long duration in com
municating the one to the other our solutions. But it is nec
essary for me to tell you, as a piece of news, that I am no
longer a Cartesian, and that, nevertheless, I am farther re
moved than ever from your Gassendi, whose knowledge and
merit I, for the rest, recognize. I have been impressed with
a new system, of which I have read something in the " Jour-
naux des Savans " of Paris, Leipzig, and Holland, and in the
marvellous Dictionary of Bayle, article " Rorarius " l ; and since
then I believe I see a new aspect of the interior of things.
This system appears to unite Plato 2 and Democritus, Aristotle 2
and Descartes, the scholastics with the moderns, theology and
ethics with the reason. It seems to take the best from all
sides, and then it goes much farther than any has yet
gone. I find in it an intelligible explanation of the union of
soul and body, of which I had before this despaired. I find
the true principles of things in the Unities of Substance, which
this system introduces, and in their harmony pre-established
by the primitive Substance. I find therein a wonderful sim
plicity and uniformity, so that it may be said that this sub
stance is everywhere and always the same thing, differing
only in degrees of perfection. I see now what Plato meant
when he assumed matter to be an existence imperfect and
transitory ; what Aristotle meant by his Entelechy ; what that
promise of another life is which Democritus himself made
according to Pliny ; how far the Sceptics were right in de
claiming against the senses ; how animals are in fact automata
1 Cf. Gerhardt, Vol. 4, pp. 524-554, the article " Rorarius " with Leibnitz's
remarks. — TR.
2 Plato, 427-347 B.C. ; Aristotle, 384-322 B.C. — TR.
CH. i] ON HUMAN UNDERSTANDING 67
according to Descartes, and liow they have, nevertheless, souls
and feeling according to the opinion of mankind ; how it is
necessary to explain rationally those who have lodged life and
perception in all things, as Cardan,1 Campanella,1 and, better
than they, the late Countess of Connaway, a Platonist, and our
friend, the late M. Francois Mercure van Helmont 2 (although
elsewhere bristling with unintelligible paradoxes), with his
friend, the late Mr. Henry More.2 How the laws of nature (a
good part of which were unknown before this system) have
their origin in principles superior to matter, and how, never
theless, everything takes place mechanically in matter, in
which respect the spiritualizing authors I just named have
failed with their Archaei,3 and even the Cartesians, in believ-
1 Girolamo Cardano, 1501-1576 ; Tommaso Campanella, 1568-1639 ; cf. Erd-
mann, Grundriss d. Gesch. d. Philos., 3d ed., Vol. 1, §§ 242, 246, Berlin: Wil-
helm Hertz, 1878, and the English translation of the same, London: Swan
Sonnenschein & Co., 1889; also the articles "Cardan" and " Campanella" in
the EncyclopsRdia Britannica, 9th ed. — TR.
2 Van Helmont, 1618-1698: Henry More, 1614-1687. — TR.
3 Archssus, i. Modern Latin, from the Greek apxcuo?, ap\r), that which is at
the beginning, source, origin, a first principle. Littre defines the term thus:
" Arche'e. Terme de physiologie ancienne. Principe immaterial different de
1'ame intelligent et qu'on supposait presider a tous les phenomenes de la
vie materielle." I.e. "A term of ancient physiology. An immaterial princi
ple different from the intelligent soul, and which is supposed to preside over
all the phenomena of the material life." The Century Dictionary gives the
following exposition and illustration: "In the philosophy of Paracelsus and
other spagyrics, mystics, and theosophists, a spirit or invisible man or animal
of ethereal substance, the counterpart of the visible body, within which it
resides, and to which it imparts life, strength, and the power of assimilating
food. The word is said to have been used by Basil Valentine, a German
chemist of the fifteenth century, to denote the solar heat as the source of the
life of plants. Paracelsus uses it with the above meaning. It is frequent in
the writings of Van Helmont, who explains it as a material pre-existence of the
human or animal form in posse. He regards the archreus as a fluid, i.e. as a
semi-material substance like air, and seems to consider it a chemical constituent
of the blood. Paracelsus has particularly made use of the hypothesis of the
archaeus to explain the assimilation of food. This function of the archeeus
became prominent in medicine. Van Helmont calls it the doorkeeper of the
stomach (janitor stomachi). There are further divarications of meaning.
Also spelled Archeus."
"As for the many pretended intricacies in the instance of the efformation
of Wasps out of the Carcase of a Horse, I say, the Archei that formed them
are no parts of the Horse's Soul that is dead, but several distinct Archei that
do as naturally joyn with the matter of his body, so putrified and prepared,
as the Crowes come to eat his flesh." — Dr. H. MORE, Antidote against
Atheism, app. xi.
Cf. Leibnitz: Considerations sur le Principe de Vie et sur les Natures Plas-
68 LEIBNITZ'S CRITIQUE OF LOCKE [BK. i
ing that immaterial substances altered if not the force, at
least the direction or determination, of the motions of bodies,
whereas the soul and the body retain perfectly each its own
laws, according to the new system, and yet one obeys the
other as much as is necessary. In fine, it is since I have med
itated upon this system that I have found out how the souls
of beasts and their sensations are in no sense prejudicial to
the immortality of human souls, or, rather, how nothing is
more suited to establish our natural immortality than to con
ceive that all souls are imperishable (morte carent animce),
without, however, the fear of metempsychoses, since not only
the souls, but further, the animals endure and will endure liv
ing, feeling, acting ; it is everywhere as here, and always and
everywhere as with us, according to what I have already said
to you, except that the conditions of animals are more or less
perfect and developed, without there ever being a need of
souls wholly separate, while we nevertheless have always
spirits as pure as possible, notwithstanding our (physical)
organs, which cannot disturb by any influence the laws of our
(spiritual) spontaneity. I find the vacuum and atoms excluded
in quite another way than by the sophism of the Cartesians,
grounded in the pretended coincidence of the idea of body and
extension. I see all things determined and adorned beyond
anything hitherto conceived; matter everywhere organic, no
sterile, neglected vacuum, nothing too uniform, everything
varied, but with order ; and, what passes imagination, the
entire universe in epitome, but with a different aspect in each
of its parts, and likewise in each of its unities of substance.
Besides this new analysis of things, I have a better compre
hension of that of notions or ideas, and of truths. I under
stand what a true, clear, distinct, adequate idea is, if 1 dare
adopt this word. I understand what are primitive truths, and
true axioms, the distinction between necessary truths and
tiqnc-s par V Auteur dc r Harmonic PreetabUe, published in the "Histoire des
Ouvrages des Savans," May, 1705, Gerhardt, Vol. (5, pp. 539-546; Erdmann,
pp. 429-432; translation, Duncan, Philo*. Works of Leibnitz, pp. K>3-1<>9. See
also Erdmann, Grundris* d. Gwh. '1. Philos. 3d ed., Vol. 1, § 241, 7, Vol.2,
§ 290, 12, or the English translation of the same. Slight additional information
may be found in the Encydop&clia Britannica, 9th ed., under the article,
''Medicine," in the part giving, an account of Paracelsus and Van Hel-
mont. — TK. "
c-j. i] ON HUMAN UNDERSTANDING 69
truths of fact, between the reasoning of men and the consecu
tions of animals, which are a shadow of the reasoning of men.
In short, you will be surprised to hear all that I have to say
to you, and, above all, to understand how much the knowledge
of the grandeur and of the perfection of God is therein exalted.
For I cannot conceal from you, from whom I have had nothing
concealed, how I have been thrilled now with admiration and
(if we may dare to make use of the term) with love for this
sovereign source of things and of beauty, having found that
what this system discovers surpasses everything one has hith
erto conceived. You know that I had gone a little too far
formerly, and that I began to lean toward the side of the
Spinozists/ who allow God only infinite power, without recog
nizing Either perfection or wisdom in his case, and regarding
with contempt the search for final causes, derive everything
from brute necessity. But these new lights have cured me of
this ; and since then I sometimes take the name of Theophilus.
I have read the book of this celebrated Englishman of whom
you have just spoken. I value it highly, and I have found in
it some good things. But it seems to me necessary to go
much farther, and necessary even to turn aside from his views,
since he has adopted 'some which limit us more than is neces
sary, and lower a little not only the condition of man, but,
besides, that of the universe.
Pli. You astonish me in fact with all the marvels which
you have recited to me in a manner a little too favorable for
an easy credence of them on my part. However, I will hope
that there will be something solid among so many novelties
with which you desfre to regale me. In this case you will find
me very docile. You know that it was always my disposition
to surrender myself to reason, and that I sometimes took the
name of Philaletlies. This is why. if you please, we will now
make use of these two names which are so congruous with our
mental constitution and methods. There are means of pro
ceeding to the trial, for — since you have read the book of the
1 On the relation of Leibnitz to Spinoza, see Leibniz 11. Spinoza. Em
Beit rag zur Entwicklungsgeschichte der Leibnizischeii Philosophic. Von Prof.
Dr. Ludwig Stein. Mit neunzehn Ineditis aus clem Nachlass von Leibniz.
Berlin: G. Reirner, ISM. pp. xvii., W2. Also " Mind," No. 02, p. 2!>8 ; No. 63, pp.
44."> sq., the latter an extended note on Stein's book 'by Prof. George Groom
Robertson, the late editor of " Mind." — TR.
70 LEIBNITZ'S CRITIQUE OF LOCKE [BK. i
celebrated Englishman, which gives me so much satisfaction
and which treats a good part of the subjects of which you
were just speaking, and above all, the analysis of our ideas and
knowledge — it will be the shortest way to follow the thread
of this work, and to see what you will have to say.
TIi. I approve your proposition. Here is the book.
§ 1. Ph. [I have read this book so thoroughly that I have
retained even its expressions, which I shall be careful to fol
low. Thus I shall not need to recur to the book, except at
certain junctures where we shall judge it necessary. We shall
speak first of the origin of ideas or notions (Book I.), then
of the different kinds of ideas (Book II.), and of the words
that serve to express them (Book III.), lastly of the knowl
edge and truths which therefrom result (Book IV.) ; and it is
this last part which will occupy us the most. As for the ori
gin of ideas, I believe, with this author and a multitude of
clever persons, that there are no innate ideas nor innate prin
ciples.] And, in order to refute the error of those who admit
them, it is sufficient to show, as it appears eventually, that
there is no need of them, and that men can acquire all their
knowledge without the aid of any innate impression.
Th. [You know, Philalethes, that I have been for a long
time of another opinion ; that I have always held, as I still
hold, to the innate idea of God, which Descartes maintained,
and as a consequence to the other innate ideas, which cannot
come to us from the senses. Now, I go still farther in con
formity to the new system, and I believe even that all the
thoughts and acts of our soul come from its own depths, with
no possibility of their being given to it by the senses, as you
shall see in the sequel. But at present I will put this investi
gation aside, and, accommodating myself to the received ex
pressions, since in fact they are good and tenable, and one can
say in a certain sense that the external senses are in part
causes of our thoughts, I shall consider how in my opinion
one must say even in the common system (speaking of the
action of bodies upon the soul, as the Copernicans speak with
other men of the movement of the sun, and with cause) ? that
there are some ideas and some principles which do not come to
us from the senses, and which we find in ourselves without form
ing them, although the senses give us occasion to perceive them.
CH. i] ON HUMAN UNDERSTANDING 71
I imagine that your clever author has remarked that under the
name of innate principles one often maintains his prejudices,
and wishes to free himself from the trouble of discussion, and
that this abuse doubtless has stirred up his zeal against this
supposition. He desired, no doubt, to combat the indolence
and the superficial manner of thinking of those who, under the
specious pretext of innate ideas and of truths naturally en
graved upon the mind, to which we readily give our consent,
care nothing about investigating or considering the sources,
the relations, and the certainty of this knowledge. In that I
am entirely agreed with him, and I go even farther. I would
that our analysis should not be limited, that definitions should
be given of all the terms which are capable of definition, and
that one should demonstrate, or give the means of demonstrat
ing, all the axioms which are not primitive, without distin
guishing the' opinions which men have of them, and without
caring whether they give their consent or not. There would
be more profit in this than one thinks. But it seems that the
author has been carried too far on the other side by his zeal,
otherwise very praiseworthy. He has not sufficiently distin
guished, in my opinion, the origin of the necessary truths,
whose source is in the understanding, from that of the truths
of fact drawn from the experience of the senses, and even
from those confused perceptions which are in us. You see,
then, that I do not agree with what you lay down as fact
— that we can acquire all our knowledge without the need of
innate impressions. And the sequel will show which of us is
right.]
§ 2. Ph. We shall see it indeed. I grant you, my dear The-
ophilus, that there is no opinion more commonly received than
that which establishes the existence of certain principles of
truth in which men generally agree ; this is why they are
called general notions, KOLVOL ci/votat ; whence it is inferred
that these principles must be so many impressions which our
minds receive with their existence. § 3. But though it were
certain that there are some principles in which the entire
human race is agreed, this universal consent would not prove
that they are innate if one can show, as I believe he can, an
other way through which men have been able to reach this
-imformity of opinion. § 4. But, what is much worse, this
72 LEIBNITZ'S CRITIQUE OF LOCKE [BK. i
universal consent is nowhere found, not even with regard to
these two celebrated speculative principles (for we shall speak
about the practical ones later), that ivhatever is, is; and that
it is impossible for a thing to be and not to be at the same
time. For there is a large part of the human race to which
these two propositions, which will pass doubtless for neces
sary truths and for axioms with you, are not even known.
Th. [I do not ground the certainty of innate principles upon
universal consent, for I have already told you, Philalethes,
that my opinion is that we ought to labor to be able to demon
strate all the axioms which are not primitive. I grant you
also that a consent very general, but which is not universal,
may come from a tradition diffused throughout the human
race, as the practice of smoking tobacco has been received by
nearly all nations in less than a century, although some island
ers have been found who, not being acquainted with fire even,
were unable to smoke. Thus some clever people, even among
theologians, but of the party of Arminius,1 have believed that
the knowledge of the Deity came from a very ancient and very
general tradition ; and I believe indeed that instruction has
confirmed and rectified this knowledge. It appears, however,
that nature has contributed to its attainment without learning ;
the marvels of the universe have made us think of a superior
power. A child born deaf and dumb has been seen to show
veneration for the full moon, and nations have been found,
who seemed not to have learned anything of other peoples,
fearing invisible powers. I grant you, my dear Philalethes, that
this is not yet the idea of God that we have and ask for ; but
this idea itself does not cease to be in the depths of our souls,
without being put there, as we shall see, and the eternal laws
of God are in part engraved thereon in a manner still more
legible and by a species of instinct. But they are practical
principles of which we shall also have occasion to speak. It
must be admitted, however, that the inclination we have to
recognize the idea of God is in human nature. And, even if
the first instruction therein should be attributed to revelation,
the readiness which men have always shown to receive this
doctrine comes from the nature of their souls.2 But Ave will
1 James Arminins, 15GO-1609, a distinguished Dutch theologian. — TR.
2 From this point on Gerhardt, whose edition, it -will be remembered, is the
CH. i] ON HUMAN UNDERSTANDING 73
suppose that these ideas which are innate comprehend incom
patible notions.
§ 19. Ph. Although you maintain that these particular and
self-evident propositions, whose truth is recognized as soon as
one hears them stated (as that green is not red), are received
as consequences of these other more general propositions,
which are regarded as so many innate principles, it seems that
you do not at all consider that these particular propositions
are received as indubitable truths by those who have no knowl
edge of these more general maxims.
Th. I have already replied to that above. We build on these
general maxims as we build upon the majors, which are sup
pressed when we reason by enthymemes ; for, although very
often we do not think distinctly of what we do in reasoning
any more than of what we do in walking and leaping, it is
always true that the force of the conclusion consists in part in
that which is suppressed and could not elsewhere arise, as you
will find should you wish to prove it.
§ 20. Ph. But it seems that general arid abstract ideas are
more foreign to our mind [than notions and particular truths ;
consequently particular truths will be more natural to the
mind than the principle of contradiction, of which you admit
they are only the application].
Th. It is true that we commence sooner to perceive particu-
basis of the present translation, transposes the text as given by Erdmann and
Jacques as follows: "Mais nous jugerons que ces idees qui sont innees, ren-
ferment des notions incompatibles," the first three words of which will be
found in Erdmann, p. 207, b., about two-thirds down the page, Jacques, Vol. 1,
p. 29, about two-thirds down, the remainder in Erdmann, p. 211, a., at the
middle of the page, Jacques, p. 36, first third, just preceding § 19 in each case,
whence the three texts go on in agreement until § 26, G., p. 72, E., p. 212, b.,
J. , p. 39. Here the Gerhardt text has the following : " S'il y a des verites innees,
ne faut il pas qu'il y ait dans la suite, que la doctrine externe ne fait qu'exciter
icy ce que est en nous " : taking up with the words " dans la suite," the text
as given by E., p. 207, b., J., p. 29, where it previously left it, the three texts
continuing again in agreement until the words " des qu'on s'appercoit," G., p.
79, last third, E., 211, a., at the middle, J., 36, first third, whence G. completes
his sentence with the last three words of the first sentence of § 26, as given by
E., 212, b., J., 39, from which point again the three texts substantially agree
to the end of Chap. 1. It may be added that the texts of Erdmann, Jacques,
and Janet follow the order of Locke's Essay. Why Gerhardt has transposed
the text in his edition, I do not know, as he has not alluded to the matter.
From his statement that " the present impression has been newly compared
with the original, so far as it is still extant " (Introduction, p. 10), I presume
that the transposition is due to his fidelity to this original. — TR.
74 LEIBNITZ'S CRITIQUE OF LOCKE [BK. i
lar truths when we commence with ideas more complex and
gross ; but that does not prevent the order of nature from com
mencing with the most simple, and the proof of the more par
ticular truths from depending upon the more general, of which
they are only examples. And when we wish to consider what
is in us virtually and before all apperception, we are right in
commencing with the most simple. For the general principles
enter into our thoughts, of which they form the soul and the
connection. They are as necessary thereto as the muscles and
sinews are for walking, although we do not at all think of
them, The mind leans upon these principles every moment,
but it does not come so easily to distinguish them and to rep
resent them distinctly and separately, because that demands
great attention to its acts, and the majority of people, little
accustomed to think, has little of it. Have not the Chinese
like ourselves articulate sounds? and yet being attached to
another manner of writing, they have not yet thought of
making an alphabet of these sounds. Thus it is that one
possesses many things without knowing it.
§ 21. Ph. If the mind acquiesces so promptly in certain
truths, cannot that acquiescence come from the consideration
itself of the nature of things, which does not allow it to judge
of them otherwise, rather than from the consideration that
these propositions are engraved by nature in the mind ?
Tk. Both are true. The nature of things and the nature of
mind agree. And since you oppose the consideration of the
thing to the apperception of that which is engraven in the
mind, this objection itself shows, sir, that those whose side you
take understand by innate truths only those which would be
approved naturally as by instinct, and even without knowing
it, unless confusedly. There are some of this nature, and we
shall have occasion to speak of them. But what is called nat
ural light supposes a distinct knowledge, and very often the
consideration of the nature of things is nothing else than the
knowledge of the nature of our mind, and of these innate ideas
which we have no need to seek outside. Thus I call innate
the truths which need only this consideration for their verifi
cation. I have already replied (§ 5) to the objection (§ 22)
which claimed that when it is said that innate notions are
implicitly in the mind, the statement must mean simply that
en. i] ON HUMAN UNDERSTANDING 75
it has the faculty of knowing them ; for I have pointed out
that besides this it has the faculty of finding them in itself,
and the disposition to approve them when it thinks of them as
it should.
§ 23. Ph. It seems, then, that you claim that those to whom
these general maxims are proposed for the first time learn
nothing which is entirely new to them. But it is clear that
they learn first the names, then the truths, and even the ideas
upon which these truths rest.
Th. The question here is not of names, which are in some
sense arbitrary, while ideas and truths are natural. But, with
respect to these ideas and truths, you attribute to us, sir, a
doctrine which we have strongly repudiated ; for I agree that
we learn ideas and innate truths either in considering their
source, or in verifying them through experience. Thus I do
not make the supposition which you aver, as if, in the case of
which you speak, we learned nothing new. And I cannot
admit this proposition : all that one learns is not innate. The
truths of numbers are in us, and we are not left to learn them,
either by drawing them from their source when we learn them
through demonstrative proof (which shows that they are in
nate), or by testing them in examples, as do ordinary arithme
ticians, who, in default of a knowledge of the proofs, learn
their rules only by tradition, and, at most, before teaching
them, justify them by experience, which they continue as far
as they think expedient. And sometimes even a very skilful
mathematician, not knowing the source of another's discovery,
is obliged to content himself with this method of induction in
examining it ; as did a celebrated writer at Paris, when I was
there, who continued a tolerably long time the examination of
my arithmetical tetragonism, comparing it with the numbers
of Ludolphe,1 believing he had found therein some error ; and
he had reason to doubt until some one communicated to him
the demonstration, which for us dispenses with these tests,
which could always continue without ever being perfectly
certain. And it is this very thing, namely, the imperfection
of inductions, which may yet be verified by instances of expe
rience. For there are progressions in which one can go very
1 John Job Ludolphe, 1049-1711: his Tetragonometria Tabular in, Frank
fort, 1690.— TR.
76 LEIBNITZ'S CRITIQUE OF LOCKE [BK. i
far before noticing the changes and the laws that are found
there.
Ph. But is it not possible that not only the terms or words
which we use, but even the ideas, come to us from without ?
Tit. It would then be necessary that we should be ourselves
outside of ourselves, for the intellectual or reflective ideas are
derived from our mind; and I should much like to know how
we could have the idea of being if we were not beings our
selves, and did not thus find being in ourselves.
Ph.' But what do you say, sir, to this challenge of one of my
friends ? If any one, says he, can find a proposition whose
ideas are innate, that he can name to me, he would do me a
very great favor.
Th. I would name the propositions of arithmetic and geome
try, which are all of this nature; and, as regards necessary
truths, no others could be found.
§ 25. Ph. That will appear strange to most people. Can it
be said that the most difficult and the most profound sciences
are innate ?
Tli. Their actual knowledge is not, but much that may be
called virtual knowledge is innate, as the figure traced by
the veins of the marble is in the marble, before one discovers
them in working.
Ph. But is it possible that children, while receiving notions
that come to them from without, and giving them their con
sent, may have no knowledge of those which you suppose to
be inborn with them, and to make, as it were, a part of their
mind, in which they are, you say, imprinted in ineffaceable
characters in order to serve as a foundation ? If that were so,
nature would have taken trouble for nothing, or, at least, she
would have badly engraved their characters, since they cannot
be perceived by the eyes which see very well other things.
Th. The apperception of that which is in us depends upon
attention and order. Now, not only is it possible, but it is also
proper, that children give more attention to the ideas of the
senses, because the attention is regulated by the need. The
outcome, however, shows in the sequel that nature has not
uselessly given herself the trouble of impressing upon us in
nate knowledge, since without it there would be no means of
attaining actual knowledge of the truths necessary in the
en. i] ON HUMAN UNDERSTANDING
demonstrative sciences, and the reasons of facts ; and we
should possess nothing above the beasts.
§ 26. Ph. If there are innate truths, does it not necessarily
follow that the external doctrine only stirs up here what is in
us'? I conclude that a consent sufficiently general among men
is an indication, and not a demonstration, of an innate princi
ple ; but that the exact and decisive proof of these principles
consists in showing that their certitude comes only from what
is in us. To reply further to what you say against the general
approbation which is given to the two great speculative prin
ciples, which are, nevertheless, the best established, I may say
to you that even if they were not known they would not cease
to be innate, because they are recognized as soon as heard ;
but I will add further that at bottom everybody knows them,
and makes use at every moment of the principle of contradic
tion (for example) without considering it distinctly ; and
there is no barbarian who, in an affair of any moment, is not
offended by the conduct of a liar who contradicts himself.
Thus, these maxims are employed without an express consid
eration of them. And in nearly the same way we have virtu
ally in the mind the propositions suppressed in enthymemes,
which are set aside not only externally, but further in our
thought.
§ 5. Ph. [What you say of this virtual knowledge and of
these internal suppressions surprises me] ; for to say that
there are truths imprinted upon the soul which it does not
perceive is, it seems to me, a veritable contradiction.
Tli. [If you are thus prejudiced, I am not astonished that
you reject innate knowledge. But I am astonished that the
thought has not occurred to you that we have an infinite amount
of knowledge of which we are not always conscious, not even
when we need it. It is for the memory to preserve this, and
for the reminiscence to represent it to us, as it often, but not
always, does at need. That is very well called remembrance
(subvenire), for reminiscence needs some aid. And it must
certainly be that in this multiplicity of our knowledge we are
determined by something to renew one part rather than another,
since it is impossible to think distinctly and at once of every
thing we know.]
Ph. In that I believe you are right ; and this too general
78 LEIBNITZ'S CRITIQUE OF LOCKE [UK. i
affirmation, that we always perceive all the truths which are
in our soul, escaped me without my having given it sufficient
attention. But you will have a little more trouble in reply
ing to what I am going to show you. That is, that if you can
say of some particular proposition that it is innate, you could
maintain by the same reasoning that all propositions which
are reasonable, and which the mind could always regard as
such, are already impressed upon the soul.
Th. I agree with you in regard to pure ideas, which I oppose
to the phantoms of the senses, and in regard to necessary
truths,- or those of the reason, which I oppose to truths of
fact. In this sense it must be said that all arithmetic and all
geometry are innate, and are in us virtually, so that we can
find them there if we consider attentively and set in order
what we already have in the mind, without making use of any
truth learned through experience or through the tradition of
another, as PJato has shown in a dialogue l in which he intro
duces Socrates leading a child to abstract truths by questions
alone without giving him any information. We can then
make for ourselves these sciences in our study, and even with
closed eyes, without learning through sight or even through
touch the truths which we need ; although it is true that we
would not consider the ideas in question if we had never seen
or touched anything. For through an admirable economy of
nature we cannot have abstract thoughts which have no need
whatever of anything sensible, when that would only be of
such a character as are the forms of the letters and the sounds,
although there is no necessary connection between such arbi
trary characters and such thoughts. And if the sensible out
lines were not requisite, the pre-established harmony between
soul and body, of which T shall have occasion to speak more
fully, would have no place. But that does not prevent the
mind from taking necessary ideas from itself. You see also
sometimes how it can go far without any aid, by a logic and
arithmetic purely natural, as that Swedish youth who, in culti
vating his own (mind), went so far as to make great calcula
tions immediately in his head without having learned the
common method of computation, or even to read and write, if
I remember correctly what has been told me of him. It is
i JA>no, 82 sq.— Tu.
CH. i] ON HUMAN UNDERSTANDING 70
true that he cannot work out intricate problems, such as those
which demand the extraction of roots. But that does not at
all prevent him from being able still to draw them from its
depths by some new turn of mind. Thus that proves only
that there are degrees in the difficulty of perceiving what is in
us. There are innate principles which are common and very
easy to all ; there are theorems which are discovered likewise
at once, and which compose the natural sciences, which are
more understood in one case than in another. Finally, in a
larger sense, which it is well to employ in order to have notions
more comprehensive and more determinate, all truths which
can be drawn from primitive innate knowledge can still be
called innate, because the mind can draw them from its own
depths, although often it would not be an easy thing so to do.
But, if any one gives another meaning to the terms, I do not
wish to dispute about words.
Ph. [I have agreed with you that we can have in the soul
what we do not perceive there, for we do not always remem
ber at once all that we know, but it must be always what we
have learned or have known in former times expressly. Thus]
if we can say that a thing is in the soul, although the soul
has not yet known it, this can only be because it has the
capacity or faculty of knowing it.
Th. [Why could not this have still another cause, such as
the soul's being able .to have this thing within it without its
being perceived ? for since an. acquired knowledge can be con
cealed therein by the memory, as you admit, why could not
nature have also concealed therein some original knowledge?
Must everything that is natural to a substance which knowa
itself be known by it actually at once ? Cannot and must not
this substance (such as our soul) have many properties andf
affections which it is impossible to consider all at once and all
together ? It was the opinion of the Platonists that all our
knowledge was reminiscence, and that thus the truths which
the soul has brought with the birth of the man, and which
are called innate, must be the remains of an express anterior
knowledge. But this opinion has no foundation; and it is
easy to believe that the soul must already have innate knowl
edge in the precedent state (if there were any pre-existence),
however remote it might be, entirely as here : it would then
80 LEIBNITZ'S CRITIQUE OF LOCKE [BK. i
have to come also from another precedent state, or l it would
be finally innate, or at least concreate ; or else it would be
needful to go to infinity and to make souls eternal, in which
case this knowledge would be innate in fact, because it would
never have commenced in the soul ; and if any one claimed
that each anterior state has had something from another more
anterior, which it has not left to the succeeding, the reply will
be made that it is manifest that certain evident truths must
have been in all these states ; and in whatever manner it may
be taken, it is always clear in all states of the soul that neces
sary truths are innate, and are proved by what is within, it
not being possible to establish them through experience, as we
establish truths of fact. Why should it be necessary also
that we could have no possession in the soul of which we had
never made use ? And is it the same thing to have a thing
without using it as to have only the faculty of acquiring it ?
If that were so, we should never possess anything but the
things which we enjoy ; instead of which, we know that, be
sides the faculty and the object, some disposition in the fac
ulty or in the object, or in both, is often necessary, that the
faculty may exercise itself upon the object.]
Ph. Taking it in that way, we could say that there are
truths written in the soul which the soul has, however, never
known, and which, indeed, it will never know. This appears
to me strange.
Th. [I see there no absurdity, although in that case you
could not be assured that there are such truths. For things
more exalted than those which we can know in this present
course of life may be developed some time in our souls, when
they are in another state.]
Ph. But suppose there are truths which could be imprinted
upon the understanding without its perceiving them ; I do
not see how, in relation to their origin, they could differ from
the truths which it is only capable of knowing.
Th. The mind is not only capable of knowing them, but
further of finding them in itself ; and, if it had only the sim
ple capacity of receiving knowledge, or the passive power there
for, as indeterminate as that which the wax has for receiving
figures and the blank tablet for receiving letters, it would not
1 The reading of Gerhardt and Erdmann ; Jacques has " oil," where. — TR.
en. i] OX HUMAN UNDERSTANDING 81
be the source of necessary truths, as I have just shown that it
is ; for it is incontestable that the senses do not suffice to
show their necessity, and that thus the mind has a disposition
(active as well as passive) to draw them itself from its own
depths; although the senses are necessary to give it the occa
sion and attention for this, and to carry it to some rather than
to others. You see, then, sir, that these elsewhere very clever
persons who are of another opinion appear not to have thought
enough upon the consequences of the difference which there is
between necessary or eternal truths and the truths of experi
ence, as I have already observed, and as all our discussion
shows. The original proof of the necessary truths comes
from the understanding alone, and the other truths come from
experience or from the observation of the senses. Our mind
is capable of knowing both; but it is the source of the former,
and, whatever number of particular experiences we may have
of a universal truth, we could not be assured of it forever by
induction without knowing its necessity through the reason.
Ph. But is it not true that if the words, to be in the under
standing, involve something positive, they signify to be per
ceived and comprehended by the understanding ?
Th. They signify to us wholly another thing. It is enough
that what is in the understanding can be found there, and that
the sources or original proofs of the truths which are in ques
tion are only in the understanding; the senses can hint at,
justify, and confirm these truths, but cannot demonstrate their
infallible and perpetual certainty.
§ 11. Ph. Nevertheless, all those who will take the trouble
to reflect with a little attention upon the operations of the
understanding will find that this consent, which the mind gives
vntlwi.it difficulty to certain truths, depends upon the faculty
of the human mind.
Th. Very well. But it is this particular relation of the
human mind to these truths which renders the exercise of the
faculty easy and natural in respect to them, and which causes
them to be called innate. It is not, then, a naked faculty
which consists in the mere possibility of understanding them ;
it is a disposition, an aptitude, a preformation, which determines
our soul and which makes it possible for them to be derived
from it. Just as there is the difference between the figures
82 LEIBNITZ'S CRITIQUE OF LOCKE [UK. i
which are given to. the stone or the marble indifferently, and
between those which its veins already indicate, or are disposed
to indicate, if the workman profits by them.
Ph. But is it not true that the truths are subsequent to the
ideas of which they are born ? Now, the ideas come from
the senses.
Th. The intellectual ideas, which are the source of neces
sary truths, do not coine from the senses ; and you admit that
there are some ideas which are due to the reflection of the
mind upon itself. For the rest, it is true that the express
knowledge .of truths is subsequent (tempore vel natura) to the
express knowledge of ideas ; as the nature of truths depends
upon the nature of ideas, before we expressly form one or the
other, and the truths, into which enter ideas which come from
the senses, depend upon the senses, at least in part. But the
ideas which come from the senses are confused, and the truths
which depend upon them are likewise confused, at least in
part; while the intellectual ideas, and the truths dependent
upon them, are distinct, and neither the one nor the other
have their origin in the senses, although it may be true that
we would never think of them without the senses.
Ph. But, in your view, numbers are intellectual ideas, and
yet it is found that the difficulty therein depends upon the
express formation of the ideas ; for example, a man knows
that 18 and 19 equal 37 with the same evidence that he knows
that 1 and 2 equal 3 ; but a child does not know the first propo
sition so soon as the second, a condition arising from the fact
that he has not formed the ideas as soon as the words.
Th. I can agree with you that often the difficulty in the
express formation of truths depends upon that in the express
formation of ideas. Yet I believe that in your example the
question concerns the use of ideas already formed. For those
who have learned to count as .far as 10, and the method of
passing farther on by a certain repetition of tens, understand
without difficulty what are 18, 19, 37 ; viz.. 1, 2, or 3 times 10
with 8, or 9, or 7 ; but, in order to draw from it that 18 plus
19 make 37, more attention is necessary than to know that 2
plus 1 are 3, Avhich at bottom is only the definition of 3.
§ 18. Ph. Furnishing propositions in which you infallibly
acquiesce as soon as you hear them is not a privilege attached
en. i] ON HUMAN UNDERSTANDING 83
to the numbers or to the ideas, which you call intellectual.
You meet these in physics and in all the other sciences, and
the senses even furnish them. For example, this proposition :
two bodies cannot be in the same place at the same time, is a
truth of which you are not otherwise convinced than of the
following maxims : It is impossible for a thing to be and not
to be in the same time; white is not red; the square is not a
circle; yellowness is not sweetness.
Th. There is a difference between these propositions. The
first, which declares the impenetrability of bodies, needs proof.
All those who believe in true and strictly formed condensa
tion and rarefaction, as the Peripatetics and the late Chevalier
Digby,1 reject it, in fact ; without speaking of the Christians
who believe, for the most part, that the contrary view —
namely, the penetration of space — is possible to God. But the
other propositions are identical, or very nearly so, and identi
cal or immediate propositions do not admit of proof. Those
who look upon the senses as furnishing them, as that one who
says that yellowness is not sweetness, have not applied the
general identical maxim to particular cases.
Ph. Every proposition composed of two different ideas, of
which one is the denial of the other — for example, that the
square is not a circle, that to be yellow is not to be sweet —
will be as certainly received as indubitable, as soon as its
terms are understood, as this general maxim : It is impossible
for a thing to be and not to be in the same time.
Th. That is, the one (namely, the general maxim) is the
principle, and the other (that is to say, the negation of one
idea by another opposed to it) is its application.
Ph. It seems to me rather that the maxim depends upon
this negation, which is its ground; and that it is, besides,
much easier to understand that what is the same thing is not
different, than the maxim which, rejects the contradictions.
Now, according to this statement, it will be necessary for you
to admit as innate truths an infinite number of propositions of
this kind which deny one idea by another without speaking
1 Sir Kenelm Digby, 1003-16G5, an eminent English physical philosopher,
who lived for a time in France, where he enjoyed the friendship of Descartes
and other learned men, and wrote his Treatise on the Nature of Bodies and
other works. — TR.
84 LEIBNITZ'S CRITIQUE OF LOCKE [KK. i
of other truths. Add to this, that a proposition cannot be
innate unless the ideas of which it is composed are innate ;
it will be necessaiy to suppose that all the ideas which we
have of colors, sounds, tastes, figures, etc., are innate.
Th. I do not well see how this : what is the same thing is
not different, is the origin of the principle of contradiction,
and easier ; for it appears to me that you give yourself more
freedom in. advancing that A is not P> than in saying that A is
not non-A. And the reason that prevents A from being B is
that B includes non-A. For the rest this proposition : the
sweet is not the bitter, is not innate, according to the sense
which we have given to the term innate truth. For the sen
sations of sweet and bitter come from the external senses.
Thus it is a mixed conclusion (hybrida condusio), where the
axiom is applied to a sensible truth. But as regards this
proposition : the square is not a circle, you can affirm that it
is innate, for, in considering it, you make a subsumption or
application of the principle of contradiction to what the un
derstanding itself furnishes as soon as you are conscious of
innate thoughts.
Th. Not at all, for the thoughts are acts, and the knowledge
or the truths, in so far as they are within us, even when we
do not think of them, are habitudes or dispositions ; and we
are well acquainted with things of which we think but little.
Ph. It is very difficult to conceive that a truth may be in
the mind if the mind has never thought of that truth.
Th. It is as if some one said it is difficult to conceive that
there are veins in the marble before we have discovered them.
This objection seems also to approach a little too much the
begging of the question.1 All those who admit innate truths,
without grounding them in the Platonic reminiscence, admit
some of which they have not yet thought. Besides, this
reasoning proves too much; for, if truths are thoughts, we
shall be deprived not only of the truths of which we have
never thought, but also of those of which we have thought,
and of which we no longer actually think ; and if truths are
not thoughts, but habits and aptitudes, natural or acquired,
nothing prevents there being in us some of which we have
never thought, nor will ever think.
1 Petitio princijjii. — TK..
en. ii] ON HUMAN UNDERSTANDING So
§ 27. Ph. If general maxims were innate, they would appear
more vividly in the mind of certain persons where, however,
we see no trace of them ; I may mention children, idiots, and
savages,1 for of all men these are they who have the mind
less altered and corrupted by custom and by the impress of
extraneous opinions.
Th. I believe we must reason here very differently. Innate
maxims appear only through the attention which is given to
them ; but these persons have little of it, or have it for
entirely different things. Their thoughts are mostly confined
to the needs of the body ; and it is reasonable that pure and
detached thoughts be the reward of cares more noble. It is
true that children and savages have the mind less altered by
customs, but they also have it exalted by the teaching which
gives attention. It would not be very just that the brightest
lights should shine better in minds which less deserve them,
and which are enveloped in thicker clouds. I would not then
have one give too much honor to ignorance and barbarism
when one is as learned and as clever as you are, Philalethes.
as well as your excellent author ; that would be lowering the
gifts of God. Some one will say that the more ignorant we
are, the more we approach the advantage of a block of marble
or of a piece of wood, which are infallible and sinless. But,
unfortunately, it is not by ignorance that we approach this
advantage ; and, as far as we are capable of knowledge, we
sin in neglecting to acquire it, and we shall fail so much the
more easily as we are less instructed.
CHAPTER II
XO IXXATE PRACTICAL PRINCIPLES
§ 1. Ph. Ethics is a demonstrative science, and yet it has
no innate principles. And. indeed, it would be very difficult
to produce a rule of ethics of a nature to be settled by an
assent as general and as prompt as this maxim : Wliatever
is, is.
1 For an excellent exposition of the content of the term savcir/p, cf. Andrew
Lang, Mi/th, Ritual, and Religion, Vol. 1, p. 31, and note; also chap. 3, pp.
4<> *'/., London: Longmans, Green, & Co., 1887. — TR,
80 LEIBNITZ'S CRITIQUE OF LOCKE [UK. i
Th. It is absolutely impossible that there be truths of
reason as evident as those which are identical or immediate.
And, although you can truly say that ethics has principles
which are not demonstrable, and that one of the first and most
practical is, that we ought to pursue joy and avoid sorrow, it
is needful to add that this is not a truth .which is known
purely by reason, since it is based upon internal experience, or
upon confused knowledge, for we do not feel what joy or
sadness is.
Ph. It is only through processes of reasoning, through lan
guage, and through some mental application, that you can be
assured of practical truths.
Th. Though that were so, they would not be less innate.
However, the maxim I just adduced appears of another na
ture ; it is not known by the reason, but, so to speak, by an
instinct. It is an innate principle, but it does not form a
part of the natural light, for it is not known luminously. But
this principle admitted, you can draw from it scientific con
sequences, and I commend most heartily what you just said of
ethics as a demonstrative science. Let us note also that it
teaches truths so evident that thieves, pirates, and bandits are
forced to observe them among themselves.
§ 2. Ph. But bandits keep the rules of justice among them
selves without considering them as innate principles.
Tit. What matters it ? Does the world concern itself about
questions of theory ?
Ph. They observe the maxims of justice only as convenient
rules, the practice of which is absolutely necessary to the con
servation of their society.
Th. [Very well. You could say nothing better in general in
respect to all men. And thus it is that these laws are written
in the soul, nameh', as the consequences of our preservation
and of our true welfare. Do you imagine that we suppose
that truths are in the understanding as independent the one of
the other as the edicts of the praetor were on his placard or
album? I put aside here the instinct which prompts man to
love man, of which I shall presently speak, for now I wish to
speak only of truths in so far as they are known by the reason.
I admit, also, that certain rules of justice cannot be demon
strated, in all their extent and perfection, without supposing
CH. nj ON HUMAN UNDERSTANDING 87
the existence of God and the immortality of the soul, and
these, where the instinct of humanity does not impel us, are
written in the soul only as other derivative truths.] Those,
however, who base justice only upon the necessities of this life
and upon the need they have of it, rather than upon the pleas
ure they ought to take in it, which is the greatest when God
is its ground, are liable to resemble a little the society of
bandits.
Sit spes t'allendi, miscebunt sacra profanis.1
§ 3. Ph. I agree with you that nature has put in all men
the desire for happiness and a strong aversion to misery.
These are the truly innate practical principles, and principles
which, according to the purpose of every practical principle,
have a continual influence upon all our actions. But they are
inclinations of the soul toward the good, and not impressions 2
of some truth which is written in our understanding.
Th. [I am delighted, sir, to see that you admit in effect
innate truths, as I shall presently say. This principle agrees
sufficiently with that which I just indicated, which prompts
us to seek joy and shun sorrow. For felicity is only a last
ing joy. Our inclination, however, does not tend to felicity
proper, but to joy — that is to say, to the present; it is the
reason which prompts to future and enduring welfare. Xow,
the inclination, expressed by the understanding, passes into a
precept or practical truth ; and if the inclination is innate, the
truth is innate also, there being nothing in the soul which
may not be expressed in the understanding, but not always by
a consideration actually distinct, as I have sufficiently shown.
The instincts also are not always practical ; there are some
which contain theoretical truths, and such are the internal
principles of the sciences and of reasoning, when, without rec
ognizing the reason in them, we employ them by a natural
instinct. And in this sense you cannot dispense with the
recognition of innate principles, even though you might be
willing to deny that derivative truths are innate. But this
would be a question of name merely after the explanation I
1 Cf. Hor. Eijist., 1, 16, 54. Horace has " miseehis." — TR.
2 Erdmann and Jacques read, " des imperfections de quelque verite." Ger-
hardt reads, "des impressions de qiielque verite." Locke lias, "impressions
of truth." Book I., chap. 3, § 3. Vol. 1, p. 158, line 5, Bohn's edition. — TR.
88 LEIBNITZ'S CRITIQUE OF LOCKE [BK. i
have given of what I call innate. And if any one desires to
give this appellation only to the truths which are received at
first by instinct, I shall not contest the point with him.]
Ph. That is well. But if there were in our soul certain
characters imprinted there by nature, like so many principles
of knowledge, we could only perceive them acting in us, as we
feel the influence of the two principles which are constantly
active in us — namely, the desire of happiness and the fear of
misery.
Tli. [There are principles of knowledge which influence us
as constantly in our reasoning processes as these practical prin
ciples influence us in our volitions ; for example, everybody
employs the rules of deduction by a natural logic without
being aware of it.
§ 4. Ph. The rules of Morality need to be proved ; they are
then not innate, like that rule which is the source of the vir
tues which concern society : Do to another only what you ivould
hare him do to yourself.
Th. You always make me the objection which I have al
ready refuted. I agree with you that there are moral rules
which are not innate principles ; but that does not prevent them
from being innate truths, for a derivative truth will be innate,
supposing that we can draw it from our mind. But there are
innate truths, which we find in us in two ways — by insight
and by instinct. Those which I have just indicated, show by
our ideas what natural insight accomplishes. But there are
conclusions of natural light which are principles in relation
to instinct. It is thus that we are prompted to acts of human
ity, by instinct because it pleases us, and by reason because it
is just. There are then in us truths of instinct, which are
innate principles, which we feel and approve, although we have
not the proof of them which we obtain, however, when we give
a reason for this instinct. It is thus that we make use of
the laws of deduction conformably to a confused knowledge,
and as by instinct, but logicians show the reason of them, as
mathematicians also give a reason for what they do without
thinking in walking and leaping. As for the rule which states
that we ought to do to others only what we would have them
do to us, it needs not only proof, but also to be proclaimed. We
should wish too much for ourselves if we could have our own
CH. n] ON HUMAN UNDERSTANDING 89
way ; shall we say then that we also owe too much to others ? 1
You will tell me that the rule means only a just will. But
thus this rule, very far from being adequate to serve as a
measure, would itself need one. The true sense of the rule
is, that the place of another is the true point of view for equi
table judgment when we attempt it.]
§ 9. Ph. Bad acts are often committed without any remorse
of conscience ; for example, when cities are carried by storm,
the soldiers commit, without scruple, the worst acts ; some
civilized nations have exposed their children, some Caribbees
castrate theirs in order to fatten and eat them. Garcilasso de
la Vega2 reports that certain peoples of Peru took prisoners in
order to make concubines of them, and supported the children
up to the age of thirteen, after which they ate them, and
treated in the same manner the mothers so soon 'as they no
longer bore children. In the travels of Baumgarten 3 it is re
lated that there was a Santon4 in Egypt who passed for a holy
man, eo quod non foeminarum unquam esset etc puerorum, sed
tantum asellarum concubitor atque mularum.
Tli. Moral science (over and above the instincts like that
which makes us seek joy and shun sadness) is not otherwise
innate than is arithmetic, for it depends likewise upon demon
strations which internal light furnishes. And as the dem
onstrations do not at once leap into sight, it is no great wonder,
if men do not perceive always and at once all that they pos
sess in themselves, and do not read quite readily the characters
of the natural laiv, which God, according to St. Paid,5 has tvrit-
ten in their minds. As morality, however, is more important
than arithmetic, God has given to man instincts which prompt
1 This sentence is found in the texts of Erdmann and Gerhardt ; it is want
ing in that of Jacques. — TR.
2 Garcilasso de la Vega, 1540-1G16, the son of an Inca princess, and a Span
ish conqueror, a companion of Pizarro. His Commentaries real?* was pub
lished in two parts, the first at Lisbon, 1G09, giving an account of the native
traditions, customs, and history previous to the Spanish conquest; the second
under the separate title of Historia General del Peru, Cordova, 1017, treating
of the Spanish conquest. The earlier and more important part of the work
has been translated, with "learned and ingenious notes," by Clements R.
Markham, and published in the collection of the Hakluyt Society, 2 vols.,
London: 1860, 1871. — TR.
3 Martin Baumgarten, 1473-1535, Trarels through Egypt, Arabia, etc. In
Churchill, O. and J. Col., Vol. 1, 1744. — TR.
4 Mahometan monk. — TR. 5 Rom. 2 : 15 ; rf. 1 : 19. — TR.
90 LEIBNITZ'S CRITIQUE OF LOCivE [BK. i
at once and without reasoning to some portion, of that which
reason ordains ; just as we walk in obedience to the laws
of mechanics without thinking of these laws, and as we eat
not only because eating is necessary for us, but further and
much more because it gives us pleasure. But these instincts
do not prompt to action in an invincible way ; the passions
may resist them, prejudices may obscure them, and contrary
customs alter them. Nevertheless, we agree most frequently
with these instincts of conscience, and we follow them also
when stronger impressions do not overcome them. The great
est and most healthy part of the human race bears them wit
ness. The Orientals, the Greeks and Romans, the Bible
and the Koran agree in respect to them; the Mahometan
police are wont to punish the thing Baumgarten tells of, and
it would be needful to be as brutalized as the American savage
111 order to approve their customs, full of a cruelty which sur
passes even that of the beasts. Yet these same savages per
ceive clearly what justice is on other occasions ; l and although
there is no bad practice, perhaps, which may not be authorized
in some respects and upon some occasions, there are few of
them, however, which are not condemned very frequently and
by the larger part of mankind. That which has not been at
tained without reason, and was not attained by reasoning alone,
should be referred in part to the natural instincts. Custom!
tradition, discipline, are mingled therein, but it is due to in
stinct (le naturel) that custom is turned more generally to the
good side of these duties. In the same way,2 the tradition of
God's existence is due to instinct (le naturel). Xow nature
1 f[f. .T. G. Schurman, TIic EMiirnl Import of Darwinism, pp. 256-200, Xew
York : Charles Scribner's Sons, 1887. He states that " some growings amid the
general darkness incline me, at least tentatively, to the belief that, apart from
the domestic virtues, there is no such great difference between the morals of
Christians and the morals of savages" (p. 25(5). This statemeiit is modified
further on, pp. 25S, 259, and finally takes the following form: " The fighting
men, actual and potential, in every uncivilized community recognize the same
rights, obligations, and duties toward one another as constitute the essence of
civilized morality. You never find a man without a moral nature, a nature
essentially like our own : but the objects he includes within the scope of its
outgoings vary" (p. 259). For the real significance of such facts, <•/. Ex-
Pres. E. G. Robinson, of Brown University, Principles and Practice of Moral
ity, p. 43, Boston: Silver, Burdett & Co., 1888. — TR.
2 Gerhardt reads, "C'est eomine le naturel" etc.; Erdmann and Jacques,
"Le naturel," etc. — TR.
en. n] ON HUMAN UNDERSTANDING 91
gives to man and also to most of the animals affectionate and
tender feeling for those of their species. The tiger even j>ar-
cit cognatis masculis;1 whence comes this bon mot of a Roman
jurisconsult, Qala inter o nines homines natura cognationem
constituit, uncle hominum homini insidiari nefas esse. Spiders
form almost the only exception, and these eat one another
to this extent that the female devours the male after having
enjoyed him. Besides this general instinct of society, which
may be called philanthropy in man, there are some more par
ticular forms of it, as the affection between the male and the
female, the love which father and mother bear toward the chil
dren, which the Greeks call aropyrjf and other similar inclina
tions which make this natural law, or this image of law rather,
which, according to Roman, jurisconsults, nature has taught
the animals. But in man in particular there is found a certain
regard for dignity, for propriety, which leads him to conceal
the things which lower us, to be sparing of shame, to have
repugnance for incests, to bury dead bodies, not to eat men at
all, no/ living animals. One is led further to be careful of his
reputation, even beyond need, and of life; to be subject to
remorse of conscience, and to feel these laniatus et ictus,
these tortures and torments of which Tacitus, following Plato,
speaks ;3 besides the fear of a future and of a supreme power
which arises, moreover, naturally enough. There is reality in
all that ; but at bottom these natural impressions, whatever
they may be, are only aids to the reason and indices of the
plan of nature. Custom, education, tradition, reason, contrib
ute much, but human nature ceases not to participate therein.
It is true that without the reason these aids would not suffice
to give a complete certitude to morals. Finally, will 3*011 deny
that man is naturally led, for example, to withdraw from vile
things, under a pretext that races are found who like to speak
only of filth, that there are some, indeed, whose mode of life
obliges them to handle excrements, and that there are people
of Boutan, where those of the king pass as an aromatic ? I
think that you are of iny opinion at bottom in regard to these
natural instincts which tend toward what is right and decent ;
1 Juv. Sat., 15, 159-100. — TR.
2 The reading (now. a-ropy*?) of Erdmann and Jacques. Gerhardt's reading,
bpyyv, is evidently an error. — TR. 3 Goryias, 524 E ; Ann. 6, 6. — TR.
92 LEIBNITZ'S CRITIQUE OF LOCKE [BK. i
although you will say, perhaps, as you have said with regard
to the instinct which prompts to joy and felicity, that these
impressions are not innate truths. But I have already replied
that every feeling is the perception of a truth, arid that the
natural feeling is the (perception) of an innate truth, but very
often confused, as are the experiences of the external senses ;
thus you can distinguish the innate truths from the natural
light (which contains only the distinctly knowable), as the
genus must be distinguished from its species, since the innate:
truths comprehend both the instincts and the natural light.]
§ 11. Ph. A person who knew the natural limits of justice
and injustice, and (who) would not cease confusing them with
each other, could only be regarded as the declared enemy of
the repose and the welfare of the society of which he is a mem
ber. But men confuse them every moment, consequently they
do not know them.
Th. [That is taking things a little too theoretically. It
happens every day that men act contrary to their knowledge in
concealing these (limits) from themselves when they turn the
mind elsewhere, in order to follow their passions ; otherwise,
we should not see people eating and drinking what they know
must cause them sickness and even death. They would not
neglect their business ; they would not do what entire nations
have done in certain respects. The future and reason rarely
make so strong an impression as the present and the senses.
That Italian knew this well, who, before being put to torture,
proposed to have the gallows continually in sight during the
torments in order to resist them, and they heard him say some
times, " lo ti vedo," which he explained afterward when he had
escaped. Unless you firmly resolve to look upon the true good
and the true evil with the purpose of following or shunning
them, you find yourself carried away, and it happens, with re
gard to the most important needs of this life, as it happens with
regard to paradise and hell in the case of those, indeed, who
believe in them the most : —
Cantantur h?ec, laudantur h?ec,
Dicuntur, audhmtur.
Scribuntur hsec, leguntur hsec,
Et lecta negliguntur.]
CH. n] ON HUMAN UNDERSTANDING 93
Ph. Every principle which you suppose innate can only be
known by each one as just and advantageous.
Th. [You always return to this supposition, which I have
refuted so many times, that every innate truth is known
always and by all.]
§ 12. Ph. But a public permission to violate the law proves
that this law is not innate; for example, the law requiring the
love and preservation of children was violated among the
ancients when they permitted their exposure.
Th. [This violation supposed, it follows only that you have
not well read these characters of nature written in our soul,
but sometimes obscure enough by reason of our excesses, not
to mention that, in order to have a perfectly clear perception
of the necessity of duties, men must see the demonstration of
them — a condition that is rarely fulfilled. If geometry were as
much opposed to our passions and present interests as is ethics,
we should contest it and violate it but little less, notwith
standing all the demonstrations of Euclid1 and of Archimedes,1
which you would call dreams and believe full of paralogisms ;
and Joseph Scaliger, Hobbes,2 and others, who have written
against Euclid and Archimedes, would not find themselves in
such a small company as at present. It was only the passion
for glory, which these authors believed they found in the quad
rature of the circle and other difficult problems, which could
1 Euclid, not to be confounded with Euclid of Megara, a pupil of Socrates,
founder of the Megari an school, the fundamental principle of whose philosophy
was the union of the Eleatic idea of beiny with the Socratic idea of the f/nufL
The date of neither his birth nor death is known. Proclus, the Neo-Platonist,
410-485 A.D., says that Euclid lived in the time of Ptolemy I., king of Egypt,
who reigned from 32:3-285 B.C., and that he was younger than Plato's associates,
but older than Eratosthenes, "27(5-2 — 196-2 B.C.," "the celebrated scholar
whose chronological dates were adopted for the history of philosophy " (Zeller,
Outlines, §§ 3, (5(5), and Archimedes, 287-212 B.C. Proclus preserves Euclid's
reply to King Ptolemy, who asked him if there were no easier way to learn
geometry than by studying his elements. "There is no royal road to geom
etry."— TR.
2 Thomas Hobbes, 1588-1070. The statement of his geometrical principles
in opposition to those of Euclid is found in the Appendix to the English trans
lation of the De Corpore, which appeared about the middle of 1(556, entitled
Six Lessons to the Professors of Mathematics, one of Geometry, the other of
Astronomy, in the University of Oxford, English Works, Vol. 7, pp. 181-350.
For an account of the controversy in which these appeared, cf. George Croom
Robertson, Hobbes, pp. 1(57-178 (Philosophical Classics). Edinburgh: William
Blackwood & Sons, 1886. — TR.
LEIBNITZ'S CRITIQUE OF LOCKE [KK. i
blind to such a point persons of so great merit. And if others
Lad the same interest, they would make use of it in much the
same manner.]
Ph. Every duty carries the idea of law, and a law cannot
be known or supposed without a legislator who has prescribed
it, or without reward and without punishment.
Tli. [There can be natural rewards and penalties without
a legislator ; intemperance, for example, is punished by disease.
As this, however, does not injure all at first, 1 admit that there
are few precepts to which you would necessarily be bound if
there were not a God who leaves no crime without chastise
ment, no good act without reward.]
Ph. The ideas of a God and of a life to come must then also
be innate.
Th. [I am agreed in the sense in which I have explained
myself.]
Ph. lUit these ideas are so far from being written by nature
in the minds of all men, that they even do not appear very clear
and very distinct in the minds of many students, who also pro
fess to examine things with some accuracy ; so far are they
from being known by every human being.
Th. You return again to the same proposition, which main
tains that what is not known is not innate, which I have, how
ever, refuted so many times. What is innate is not at first
known clearly and distinctly as such ; often much attention
and method is necessary in order to its perception, the student-
class do not always adduce it, still less every human being.
§ 13. Ph. But if men can be ignorant of or call in question
that which is innate, it is in vain for you to speak to us of in
nate principles, and to claim to show us their necessity; very
far from their being able to serve as our instructors in the truth
and certitude of things, as is maintained, we shall find our
selves, with these principles, in the same state of uncertainty
as if they were not in us.
Th. You cannot call in question all the innate principles.
You were agreed in regard to identical propositions or the
principle of contradiction, admitting that there are incontest
able principles, although you would not then recognize them
as innate ; but it does not at all follow that everything which
en. n] ON HUMAN UNDERSTANDING 95
is innate and necessarily connected with these innate princi
ples, is also at first indubitably evident.
Ph. ]STo one that I know of has yet undertaken to give us an
exact catalogue of these principles.
Th. But has any one hitherto given us a full and exact
catalogue of the axioms of geometry ?
§ 15. Ph. My Lord Herbert 1 has been pleased to point out
some of these principles, which are : 1. There is a supreme
God. 2. He ought to be served. 3. Virtue united with piety
is the best worship. 4. Repentance for sin is necessary.
5. There are penalties and rewards after this life. I agree
that these are evident truths and of such a nature that when
well explained a reasonable person can scarcely avoid giving
them his consent. But our friends say that they are very far
from being so many innate impressions, and if these five
propositions are common notions written in our souls by the
finger of God, there are many others which we ought also to
put into this class.
Th. I agree with you, sir, for I take all the necessary truths
as innate, and I connect with them also the instincts. But, I
agree with you, that these five propositions are not innate prin
ciples ; for I hold that they can and ought to be proved.
§ 18. Ph. In the third proposition, that virtue is the wor
ship most agreeable to God, it is not clear what is meant by
virtue. If you understand it in the sense most commonly
given to the term, 'I mean that which passes as praiseworthy
according to the different opinions which prevail in different
countries, this proposition is so far from being evident that it
is not even true. If you call virtue- the acts which are con
formed to the will of God, this will be almost idem per idem,
and the proposition will teach us nothing of importance ; for
it would mean only that God is pleased with that which is con
formed to his will. It is the same with the notion of sin in
the fourth proposition.
i Lord Edward Herbert of Cherlmry, 1581-1648. His DC Veritatc, Paris.
1G24, has had considerable influence on English philosophical and reli^ioub
thought, and is of some importance in the interpretation of the polemic oi
Locke's Essay. — TR.
'2 For an excellent but brief statement and discussion of the main theories of
virtue, <\f. E. G. Robinson: Principles and Practice of Morality, pp. 140-
180. — TR.
90 LEIBXITZ'S CRITIQUE OF LOCKE [BK. i
Th. I do not remember to have remarked that virtue is
commonly taken as something which depends upon opinion ;
at least, the philosophers do not make it that. It is true that
the name of virtue depends upon the opinion of those who
give it to different habits or actions, according as they deem
them good or bad and use their reason ; but all are sufficiently
agreed as to the notion of virtue in general, although they dif
fer in its application. According to Aristotle l and several
others, virtue is a habit of restraining the passions by the rea
son, and still more, simply a habit of acting according to rea
son. And that cannot fail to be agreeable to him who is the
supreme and final reason of things, to whom nothing is indif
ferent, and the acts of rational creatures less than all others.
§ 20. Ph. You are wont to say that the custom, the educa
tion, and the general opinions of those with whom you con
verse may obscure these principles of morality which you
suppose innate. But if this reply is a good one, it annihilates
the proof which you pretend to draw from universal consent.
The reasoning of many men reduces to this : The principles
which men of right reason admit are innate ; we and those
of our mind are men of right reason ; consequently our princi
ples are innate. A pleasant method of reasoning, which goes
straight on to infallibility !
Th. For myself, I make use of universal consent, not as a
principal proof, but as a confirmatory one ; for innate truths
taken as the natural light of reason bear their marks with
them as does geometry, for they are wrapped up in the im
mediate principles which you yourselves admit as incontesta
ble. But I grant that it is more difficult to distinguish the
instincts and some other natural habits from custom, although
it may very often be possible so to do. For the rest, it appears
to me that people who have cultivated their minds have some
ground for attributing the use of right reason to themselves
rather than to the barbarians, since in subduing them almost
as easily as they do animals they show sufficiently their supe-
1 Eth. Xic. II. 6, ad in it. Cf. Zeller : Outlines of the Hist, of Greek Philos.,
§ 61 ; and E. Wallace : Outline's of the Philos. of Aristotle, 3d ed., § 59, pp. 97-
99. Cambridge : University Press, 1883. In connection with each section of
his brief English statement and exposition, Wallace gives the Greek text of
" the more important passages in Aristotle's writings," with references to the
Berlin Academy edition of Aristotle. — TK.
CH. ii] ON HUMAN UNDP: R STANDING 97
riority. But if they cannot always succeed in this, it is be
cause just like the animals they conceal themselves in the
thick forests, where it is difficult to hunt them down and the
game is not worth the candle. It is doubtless an advantage to
have cultivated the mind, and if we may speak for barbarism
as against culture, we shall also have the right to attack rea
son in favor of the animals, and to take seriously the witty
sallies of M. Despreaux,1 in one of his satires, where, in order
to contest with man his prerogative over the animals, he asks,
whether,
The bear is afraid of the passer-by, or the passer-by of the bear ;
And if, by decree of the shepherds of Libya,
The lions would vacate the parks of Numidia, etc.
We must, however, admit that there are some points in which
the barbarians surpass us, especially as regards vigor of body ;
and as regards the soul even we may say that in certain respects
their practical morality is better than ours, because they have not
the avarice of hoarding nor the ambition of ruling. And we
may even add that association with Christians has made them
worse in many respects.2 They have taught them drunkenness
(when carrying them the water of life), swearing, blasphemy,
and other vices, which were little known to them. There is
with us more of good and of evil than with them : a bad Euro
pean is worse than a savage — lie refines upon evil.3 Still.
nothing should prevent men from uniting the advantages which
nature gives to these peoples with those which reason gives us.
1 Nicolas Boileau-Despreaux, 1 030-1711. The passage quoted is from Sat. 8,
62-64. The text as "I yen by all the editions I have been able to consult,
twelve, ranging from 1716-1 <S73, reads thus:
" L'onrs a peur du passant, on le passant do Fours;
Et si, sur nn edit des patres de Nnbie,
Les lions de Barca videraient la Lybie:'' etc.
Lines 63 and 64 of the text, as given by Leibnitz, editions of Gerhardt and
Erdmann, Jacques modernizing the spelling and correcting the misplacement
of " de " and " des " in line (53, read thns :
" Et si par un edit de pastres des Lybie
Les Lions vuideroient les pares de Nnmidie," etc.
It seems evident that Leibnitz misquoted the lines. — TK.
2 Compare J. G. Schurman : The Ethi<:u.l Import of Dan1: in ism, pp. 256-260
as above. — TK.
3 The French is : " il rafine sur le mal." — TR.
08 LEIBNITZ'S CRITIQUE OF LOCKE [UK. i
Ph. But what reply do 3*011 make, sir, to this dilemma of
one of my friends ? I would be pleased, he says, to have the
advocates of innate ideas tell me whether these principles can
or cannot be effaced by education and custom. If they cannot
be effaced we ought to find them in all men, and they should
clearly appear in the mind of each particular man. If they
can be altered by extraneous ideas, they ought to appear more
distinctly and with more lustre the nearer they are to their
source. I mean in children or illiterate people, upon whom
extraneous opinions have made less impression. Let them
take which side they please, they will clearly see, he says, that
it is contradicted by indubitable facts and by continual expe
rience.
Th. I am astonished that your clever friend has confounded
obscurity with ejfacement, as some in your party confound non-
being with non-appearance. Innate ideas and truths cannot
be effaced, but they are obscured in all men (as they are now)
by their inclination toward the needs of the body, aiid oftener
still by the occurrence of bad customs. These characteristics
of the internal light would always be shining in the under
standing and would give fervor to the will, if the confused
perceptions of sense did not engross our attention. It is the
straggle of which Holy Scripture no less than ancient and
modern philosophy speaks.
Ph. Thus, then, we find ourselves in darkness as thick and
in uncertainty as great as if there were no such light.
Th. God forbid ; we should have neither science nor law,
nay, not even reason.
§ 21, 22, etc. Ph. I hope that you will at least admit the
force of prejudice, which often causes that to pass as natural
which has come from the bad instruction to which children
have been exposed, and the bad customs which education and
association have given them.
Th. I admit that the excellent author whom you follow says
some very fine things upon that subject, and which have their
value if they are taken as they should be ; but I do not believe
that they are opposed to the doctrine properly understood of
nature or of innate truths. And I am confident that he will not
extend his remarks too far ; for I am equally persuaded that
a great many opinions pnss for truths which are only the effects
en. n] ON HUMAN UNDERSTANDING
of custom and of credulity, and that there are many such opin
ions, too, which certain philosophers would fain account for as
matters of prejudice, which are, however, grounded in right
reason and in nature. There is as much or more ground for de
fending ourselves from those who through ambition oftenest
make pretensions to innovation, than for challenging ancient im
pressions. And after having meditated sufficiently upon ancient
and modern thought, I have found that the majority of the re
ceived doctrines may bear a good sense. So that I wish that
sensible men would seek to satisfy their ambition by occupy
ing themselves rather in building and advancing than in retro
grading and destroying. And I desire them to resemble the
Komans who constructed beautiful public works, rather than
that Vandal king 1 whom his mother charged to seek the de
struction of these grand structures, since he could not hope for
the glory of equalling them.
Ph. The aim of the clever class who have contended against
innate truths has been to prevent men from handing round
their prejudices and seeking to cover their idleness beneath
this fair name.
Th. We are agreed upon this point, for, very far from ap
proving that doubtful principles be received, I would, for my
self, seek even the demonstration of the axioms of Euclid, as
some ancients also have done. And when you ask the means
of knowing and examining innate principles, I reply, following
what I said above, that with the exception of the instincts
whose reason is unknown, you must try to reduce them to first
principles, that is to say, to axioms identical or immediate by
means of definitions, which are nothing else than a distinct
exposition of ideas. I do not doubt even but that your friends,
who have hitherto been opposed to innate truths, would ap
prove this method, which appears consonant with their princi
pal aim.
1 Chrocus, who with the Sueves and Alans is said to have passed over the
Rhine near Mayence, and following the evil counsel of his mother, to have
ravaged in the most frightful manner in Germany as in Gaul. The story is
given in the Chronicle of Idatius, chap. G2. Cf. Bouquet, Reruin Gall, et
Franc. Scriptores, Torn. 2, p. 404. — TR.
100 LEIBNITZ'S CRITIQUE OF LOCKE [BK. i
CHAPTER III
OTHER CONSIDERATIONS TOUCHING INNATE PRINCIPLES, BOTH
SPECULATIVE AND PRACTICAL
§ 3. Ph. You wish to reduce truths to first principles, and
I grant you that if there is any such principle, it is without
gainsaying this ; it is impossible for a thing to be and not to
be at the same time. It appears, however, difficult to maintain
its innate character, since you must be convinced at the same
time that the ideas of impossibility and identity are innate.
Th. It is quite necessary that those who favor innate truths
maintain and be convinced that these ideas are also innate, and
I admit that I am of their opinion. The ideas of being, of
possibility of identity, are so completely innate that they
enter into all our thoughts and reasonings, and I regard them
as essential to our mind ; but I have already said that we do
not always pay them particular attention and that we discern
them only with time. I have said hitherto that we are, so to
speak, innate unto ourselves, and since we are beings, the being
we is innate ; and the knowledge of being is wrapped up in
that knowledge which we have of ourselves. There is some
thing similar in the case of other general notions.
§ 4. Ph. If the idea of identity is natural, and consequently
so evident and so present to the mind that we ought to recog
nize it from the cradle, I would be pleased to have a child of
seven years, and even a man of seventy, tell me whether a man
who is a creature consisting of body and soul, is the same (man)
when his body is changed, and whether, metempsychosis sup
posed, Euphorbus would be the same as Pythagoras.
Th. I have stated sufficiently that what is natural to us is not
known to us as such from the cradle; and even an idea may be
known to us without our being able to decide at once all ques
tions which can be formed thereupon. It is as if some one main
tained that a child cannot have a knowledge of the square and
its diagonal, because he will have difficulty in recognizing that
the diagonal is incommensurable with the side of the square.
As for the question itself, it appears to me demonstratively
en. in] ON HUMAN UNDERSTANDING 101
solved by the doctrine of Monads, which I have elsewhere l
shown in its true light, and we shall speak more fully of this
matter in the sequel.
1 Cf. the Essay, without title, Gerhardt, 4, 427 sq., written at the beginning
of 1686, and referred to as " un petit disco urs de Metaphysique," in Leibnitz's
letter, Feb. 1-11, 1686, to the Laudgraf Ernst von Hessen-Klieiufels, G. '2, 11.
This ' Discours,' regarded by Leibnitz as the beginning of his philosophy, con
tains a summary, centring about the idea of the individual substance, of all
his previous philosophical speculation. He gained this idea, and with it a
seemingly satisfactory solution of the principal philosophical problem, at the
end of 1685 or the beginning of 168(5. For this idea, still in process of devel
opment, possessing the elements of force and individuality, but lacking those
of continuity and perceptive activity evolved between 1686 and 1697, Leibnitz,
in 1697, when the idea possessed all the elements essential to its completeness
in his system, appropriated the term "monad." This term he borrowed, not
from Giord'auo Bruno, 1548-1600, who used it in a similar though not precisely
the same sense, but from Francois Mercure Van Helmont, 1618-1699. So far
as known, the term "monad" is h'rst mentioned in the letter to Fardella,
Sept. 3-13, 1696, first published by Foucher de Careil, Nouv. lettr. et opusc. de
Leibniz, p. 328, Paris, 1857. The doctrine in substance till 1697. and thereafter
in imme, Leibnitz frequently set forth with increasing clearness and complete
ness in letters to his numerous correspondents, and in the " Acta Eruditorum "
and the " Journal des Savans." Reference may be made, among others, to the
following: Correspondence with Antoine Arnauld, 1612-1694, especially the
letter dated Venice, Mar. 23, 1690, G. 2, 1:54 ; Erdmami, 107; Jacques, 1, 443;
trans., Appendix, ; the two systematic elaborations of his system of
the year 1695, the mathematical in the Specimen dynamicum pro adunrandis
naturx lef/ibiiK, etc., Gerhardt, Leibniz, math. Schrijt., 6, 234 sq.; the meta
physical in the tiysteme nou>:eau de la nature, etc., G. 4, 477; E. 124; trans.,
Appendix, ; De ipsa natura, etc., 1698, espec. §§ 11, 12, G. 4, 504 ; E. 154 ;
J. 1, 455 (in French) ; trans., Appendix, ; Response (Repliqite,Erdma.i\n)
anx reflexions continues dans la seconde edition da Dictionnaire Critique de
M. B«ijle, etc., 1702, G. 4, 554; E. 183; trans., Appendix, ; Letters to
Knd. Christ. Wagner De ri activa corporis, June 4, 1710. G. 7, 528: E. 465;
trans., Duncan, P/iilos. Wks. of Leibnitz, 190; to Bierling, Aug. 12. 1711,
G. 7, 500; E. 677: Principes de la nature, etc., c. 1714, G. 6, 598; E. 714;
trans., Duncan, 209: La Monad.olof/ie, 1714, G. 6, 607: E. 705: trans.. Duncan,
21S, F. H. Hedge, "Jour. Spec. Philos.," Vol. 1, p. 129: Letters to Des Bosses,
G. 2, 285 sq., passim, which present most penetrating discussions of Leibnitz's
metaphysic and form the most ample commentary on the Mo»<idoln</i<> ; to De
Voider, 1643-1709, G. 2, 139 sq.. pasxhn, proving the intimate connection of
Leibnitz's dynamic and metaphysic; to Bourguet, Dec. 1714, G. 3. 575; E. 720;
to Remond (de Montmort, E. 724), Feb. 11, 1715, §§ 3, 4, G. 3, 635; to Dangi-
court, Sept. 1716, Dutens, Lcibnit. opera omnia, 3, 499; E. 745. Of the pieces
cited the most important are : The Letter to Arnauld, Mar. 23, 1690, the Fyxteme
nonreau, the De ipsa natura, the Prinapes de la nature, and the M<>nad<>-
lot/ie. As Leibnitz was occupied, more or less as circumstances permitted,
with the composition and revision of his ' New Essays,' from 1700, when Coste's
translation of Locke's 'Essay' appeared, to 1709 and perhaps later (rid. ant<>,
p. 9 and note), possibly even as late as 1714 or 1716, the relative date of com
position of the several pieces here cited to that of the ' New Essays ' can easily
102 LEIBNITZ'S CRITIQUE OF LOCKE [UK. i
§ 0. Ph. [I see very well that to you I should object in vain
that the axiom which declares that the whole is greater than its
part is not innate, under pretext that the ideas of whole ami
part are relative, dependent upon those of number and exten
sion ; since you would apparently maintain that there are ideas
conditionally innate, and that those of number and extension
are to such a degree innate.1]
Tit. You are right, and indeed I rather believe that the idea
of extension is posterior to that of whole and part.
§ 7. Ph. [What say you of the truth that God should be
worshipped ; is it innate ?]
Th. I believe that the duty of worshipping God declares that
on occasion you ought to show that you honor him beyond
every other object, and that this is a necessary consequence of
the idea of him and of his existence ; which signifies with me
that this truth is innate.
§ 8. Ph. But the atheists seem to prove by their example
that the idea of God is not innate. And without speaking
of those whom the ancients have mentioned, have not entire
nations been discovered, who have no idea of God nor of the
terms which denote God and the soul, as at the bay of Soldania,
in Brazil, in the Caribbee Islands, in Paraguay ?
Tit. [The late Mr. Fabricius,2 a celebrated theologian of
Heidelberg, has made an apology for the human race in order
be approximated. On the whole subject, cf. L. Stein, Leibniz ti. Spinoza, chap. H,
pp. 111-219, Berlin: G. Reimer, 1800, who traces the history of the rise of the
monad-doctrine from 1(580 till all the elements of the complete conception were
present in 1(507: E. Dillmann, E. ncue Dar sty. d. Leibniz. Monadetilchrc <a<f
Grunt! <1. Q/ieUcn, Leipzig: O. R. Reisland, 1801, whose monograph is an elab
orate discussion of the entire subject with references to or quotations from all
the sources. — TH.
1 The French text is : " puisque vous soutiendres apparemment, qu'il y a des
ide'es innees respectives, et que celles des nombres et de 1'e'tendue sont inneVs
aussi." — TR.
- John Lewis Fabricius, 1632-1(507. Professor, first of Greek, then of Philos
ophy and Theology, at Heidelberg. In l(i(!4 he received the title of " Conseiller
eccle'siastique de 1'electeur palatin." Some years after, when Heidelberg was
burning, he saved the archives of the church and the university, carrying
thorn first to Eberbach, then to Frankfort, where he died. The title of the
work referred to in the text (rid. ante, p. 21 also, where the name is given
Fabritius, in accord with his own signature in the letter of Feb. If5, 1673, to
Spinoza, offering him the professorship of Philosophy at Heidelberg) is: Apol
ogia f/rnrris humftni f-onfra ra/mniu'mn fithfiuMf. It appeared in 1(502. H's
collected works, with a life, were published by J. H. Heidegger, Zurich, 1(508,
in 4to. — TR.
en. in] ON HUMAN UNDERSTANDING 103
to clear it of the imputation of atheism. He was an author of
great accuracy, and decidedly above much prejudice; '.I do not,
however, pretend to enter into this discussion of facts. I grant
that entire peoples have never thought of the supreme sub
stance, nor of the nature of the soul. And I remember, that
when you wished at my request, countenanced by the illus
trious Mr. Witsen, to obtain for me in Holland a translation of
the Lord's Prayer into the language of Barantola, you were
stopped at this point : hallowed be thy name, because you
could not. make the Barantoli understand what hallowed
meant. I. remember also that in the creed made for the Hot
tentots you were obliged to express Holy Spirit by words of
the country which signify a pleasant and agreeable wind.1
This was not unreasonable, for our Greek and Latin words
TTvcv/xa, auima, xpiritun, mean ordinarily only the air or wind
we breathe, as one of the most subtile things which we know
through, the senses ; and we begin through the senses to lead
men little by little to what is beyond the senses. All this diffi
culty, however, which you rind in attaining abstract knowledge
effects nothing against innate knowledge. There are peoples
who have no word corresponding to the word being ; does any
one doubt their knowledge of what being is, although they
seldom think of it in the abstract ? Besides I find what i
have read in our excellent author on the idea of God ( Essay on
Understanding, Book I., chap. 3,2 § 9) so beautiful and so to
my liking that I cannot refrain from quoting it.3 Here it is :
"Men can scarcely avoid having some kind of idea of tilings
of which those with whom they converse often have occasion
to speak under certain names, and if the thing is one which
carries with it the idea of excellence, of grandeur, or of some
extraordinary quality which interests in some point and which
impresses itself upon the mind under the idea of an absolute
and irresistible power which none can help fearing" (I add:
and under the idea of a superlatively great goodness which
none can help loving), "such an idea ought, according to all
1 Cf. Book III., chap. 1, § 5, Tli. (2). — TR.
2 Chap. 4, in Locke's treatise, Holm's ed. — TR.
3 The French translation of Locke's original, is, in my judgment, clearer in
form of statement and style than Locke himself. Hence I have retranslated the
French into English. If any reader prefers Locke's original, he can easily find
it in the Philos. Works, Holm's ed., Vol. 1, p. 188. — TR.
104 LEIBNITZ'S CRITIQUE OF LOCKE [BK. i
appearances, to make the strongest impression and to spread
farther than any other, especially if it is an idea which accords
with the simplest insight of reason, and which flows naturally
from every part of knowledge. Xow such is the idea of God,
for the brilliant marks of extraordinary wisdom and power
appear so plainly in all the works of the creation, that every
rational creature who will reflect thereupon cannot fail to dis
cover the author of all these marvels ; and the impression that
the discovery of such a Being must naturally make upon the
souls of all those who have once heard him spoken of is so great,
and carries with it thoughts of so great weight and so adapted
to spread themselves in the world, that it appears to me wholly
strange that an entire nation of men can be found upon the
earth so stupid as to have no idea of God. This, I say, seems
to me as surprising as to think of men who should have no
idea of numbers or of tire."
I would I might always be allowed to copy word for word a
number of other excellent passages of our author, which we are
obliged to pass by. I will only say here, that this author, in
speaking of the sinyrtest lir/Jtt* of reason., which agree with the
idea of God, and of that which naturally proceeds from it. ap
pears to differ but little from my view of innate truths ; and,
concerning this, that it appears to him as strange that there
may be men without any idea of God, as it would be surprising
to find men who had no idea of numbers or of fire, I will remark
that the inhabitants of the Marian Islands, to which has been
given the name of the Queen of Spain, who has protected mis
sions there, had no knowledge of fire when they were dis
covered, as appears from the narrative which Rev. Father
Gobien,1 a French Jesuit, charged with the care of distant
missions, has given to the public and sent to me.]
r? 16. Ph. If you are right in concluding that the idea of
God is innate, from the fact that all enlightened races have
had this idea, virtue ought also to be innate because enlightened
races have always had a true idea of it.
Tli. [Xot virtue, but the idea of virtue, is innate, and per
haps you intend only that.]
1 Charles le Gobien, 1053-1708. Professor of Philosophy at Tours: secre
tary and procurator of Chinese missionaries: wrote and published a number
of works on these missions in China; his Hintoire dcs Ixles Mariannes, Parist
1700, lL>mo. — TR.
en. in] ON HUMAX UXDP:RSTAXDIXG 105
Ph. It is as certain that there is a God, as it is certain that
the opposite angles made by the intersection of two straight
lines are equal. And there has never been a rational creature
who applied himself sincerely to the examination of the truth
of these two propositions who has failed to give them his con
sent. Nevertheless, it is beyond doubt that there are many
men who, having never turned their thoughts in. this direction,
are ignorant equally of these two truths.
Th. [I admit it ; but that does not prevent them from being
innate — that is to say, does not prevent you from being able
to hnd them in yourself.]
§ 18. Ph. It would be more advantageous to have an innate
idea of substance ; but it turns out that we do not have it,
either innate or acquired, since we have it neither through
sensation nor reflection.
Th. [I am of opinion that reflection suffices to discover
the idea of substance within ourselves, who are substances.
And this notion is one of the most important. But we shall
speak of it, perhaps more fully, in the sequel of our con
ference.]
§ 20.1 Ph. If there -are innate ideas in the mind without the
mind's being actually aware of their presence, they must at
least be in the memory, whence they must be drawn by means
of reminiscence — that is to say, be known, when memory re
calls them, as so many perceptions which have been in the
mind before, unless reminiscence can subsist without reminis
cence. For this conviction, where it is an inwardly certain
one, that a given idea has previously been in our mind, is
properly what distinguishes reminiscence from every other
kind of thinking.
Th. [In order that knowledge, ideas, or truths be in our
mind, it is not necessary that we have ever actually thought of
them ; they are only natural habitudes ; i.e. dispositions and
aptitudes, active and passive, and more than a tabula rasa.
It is true, however, that the Platonists believed that we have
already actually thought of that which we recognize in our
selves ; and to refute them it is insufficient to say that we do
not at all remember it, for it is certain that an infinite number
i Gerliardt's reading. So also Locke, Philos. Work*, Vol. 1, p. 197, Bohn's
ed. — TR.
100 LEIBXITZ'8 CRITIQUE OF LOCKE [BK. I
of thoughts recur to us which we have forgotten that we
had. It has happened that a man believed he had composed a
new verse, which it turned out he read word for word a long
time previous in some ancient poet. And often we have an
extraordinary facility of conceiving certain things, because we
formerly conceived them, without remembering them. It is
possible that a child, having become blind, forgets ever having
seen light and colors, as happened at the age of two and a half
years from small-pox in the case of the celebrated Ulric Schoen-
berg, a native of Weide, in the Upper Palatinate, who died at
Konigsberg, in Prussia, in 1649, where he taught philosophy
and mathematics to the admiration of every one. It may be
that such a man has remaining effects of former impressions
without remembering them. I believe that dreams often thus
revive in us former thoughts. Julius Scaliger,1 having cele
brated in verse the illustrious men of Verona, a certain self-
styled Brugnolus, a Bavarian by birth, but afterward estab
lished at Verona, appeared to him in a dream and complained
that he had been forgotten. Julius Scaliger, not remembering
to have heard him spoken of before, did not allow himself to
make elegiac verses in his honor in consequence of this dream.
At length, the son, Joseph Scaliger,2 travelling in Italy, learned
more particularly that there had been formerly at Verona a
celebrated grammarian or learned critic of this name, who had
contributed to the re-establishment of polite literature in Italy.
This story is found in the poems of Scaliger the father, to
gether with the elegy, and in the letters of the son. It is
related also in the "Scaligerana/'3 which are culled from the
1 Julius Cresar Scaliger, 1484-1558. His Latin verse appeared in successive
volumes in l.~);W, 1,~>:U, 15;!',), 154<>, 1574. His tastes were, however, philosophi
cal and scientific rather than literary. His scientific works, in the form of
commentaries, have only a historical interest. The Exoteric-arum cxerritatio-
num liber, Paris, 1557, 4to, a philosophical treatise on the De Subtilitnte, 1552.
of Cardan (vid. ante, p. (57, note 1), is the work which best makes known
Scaliger as a philosopher. It was a popular text-hook until the final fall of
Aristotle's physics. — TR.
'2 Joseph Justus Scaliger, 1540-1(509, reputed the greatest scholar of modern
times. He was the first to set forth and apply sound principles of textual
criticism and emendation in his editions of some of the classical authors, and
with him arose a new school of historical criticism. He reconstructed the lost
Chronicle of Eusebius, a work of considerable importance in the study of
ancient history. — TR.
3 Two collections of anecdotes concerning Joseph Scaliger, numbered accord-
en. ml ON HUMAN UNDERSTANDING 107
conversations of Joseph Scaliger. It is very likely that Julius
Scaliger had known something of Brugnol which he no longer
remembered, and that the dream was partly the revival of a
former idea, although he may not have had that reminiscence,
properly so called, which makes us know that we have already
had this same idea ; at least, I see no necessity which obliges
us to assert that there remains no trace of a perception when
there is not enough of it to remind us that we have had it.]
§ 24. Pit. [I must admit that your reply is natural enough
to the difficulties which we have framed against innate truths.
Perhaps, also, our authors do not contest them in the sense in
which you maintain them. Thus I return only to say to you, sir]
that we have had some reason to fear that the view of innate
truths serves as a pretext for laziness, for exempting ourselves
from the trouble of research, and gives opportunity to masters
and teachers to lay down as a principle of principles that
principles must not be questioned.
Tli. [I have already said that if it is the aim of your friends
to advise the search for the proofs of the truths which
they can receive, without distinguishing whether or not they
are innate, we are entirely agreed ; and the view of innate
truths, of the manner in which I take them, should deter no one
from such search, for, besides being well to seek the reason of
the instincts, it is one of my great maxims that it is good to
seek demonstrations of the axioms also, and I remember that
at Paris, when the late Mr. Koberval,1 already an old man, was
ing to their date of composition. The first was written in Latin by Francois
Vertunien, a friend of Scaliger, who took notes of his conversations with
Scaliger, especially of all criticisms or anecdotes worthy of preservation, and
afterwards wrote- them out. An advocate, Francois de Sigogne, bought the
MS. long after the author's death, and published it at Saumer in 1669. The
second was written in French and Latin by two youths named Vassal), who,
when students at Leyden, habitually conversed after supper with Scaliger, then
Professor of Belles Lettres there, and on their return to their rooms wrote out
all they could remember of his conversation. Their MS. was .finally published
at La Have, 16(56, by Isaac Vossius. The edition of the Sr<illf/t'ra>i<i , accounted
the best, is that of 1740, 12mo. The story is told at length, and the Elegy of
the elder Scaliger cited, in the Cologne ed. of the Scaliyerana, 1(595, pp. 6l>-
71. — TR.
1 Gilles Personne de Roberval, a French geometer, born 1602, at Roberval, a
small village of Beauvais, died 1675 at Paris. He was Professor of Mathematics
in the Royal College of France for many years. One of the conditions of the
tenure of this chair was that its holder should propose mathematical questions
for solution, and resign iu lavor of. any one solving them better than iiimself.
108 LEIBNITZ'S CRITIQUE OF LOCKE [UK. I
laughed at because he wished to demonstrate those of Euclid
after the example of Apollonius * and Proclus,2 1 illustrated the
utility of this investigation. As for the principle of those
who say that it is wholly unnecessary to argue against the one
who denies principles, it has no authority whatever in regard to
these principles which can admit neither doubt nor proof. It
is true that, in order to avoid scandal and disturbance, regula
tions may be made regarding public disputations and some
other lectures, in virtue of which the discussion of certain
established truths may be prohibited. But this is rather a
question of police than of philosophy.]
Roberval kept the chair till his death. He is best known for his original
method for the construction of tangents. — TR.
1 Apollonius of Perga, born probably about 250 B.C., died in the reign of
Ptolemy Philopater, 222-205 B.C. Next to Archimedes, he was the most noted
of the Greek geometers. His fame has been transmitted to modern times
chiefly by his treatise on the Conic Sections, the best edition of which, and the
only one containing the Greek text that has yet appeared, is : Apollonii
perr/aei conicorum libri octo, etc., ed. Halley : Oxford, 1710, folio. He was the
first to show that all three of the conic sections can be cut from the same cone
by changing the position of the intersecting plane. — TR.
2 Proclus Diadochus, 410-485, " the great schoolman of Neo-Platonism," the
doctrines of which received at his hands the final form in which they have
come down to us. He came to Athens in his twentieth year, and remained
there teaching and writing till his death. Among his writings now extant are
a Treatise on the Sphere, Commentaries on Euclid, and on several of Plato's
dialogues, and the wholly independent works Srotxe^o"1? ©eoAo-yt/c^ Or Institutes
of Theolofj]/, and the six books et? T^V HAaTioi'o? ©eoAoytar, or Platonic Theology.
His philosophical work is found for the most part in the Commentaries on Plato.
For his mathematical work, cf. In primurn Euclidis Elementorum librum
Coiiimentarii, ex recognitione G. Friedlein : Lipsire, 1873; also George Johnston
Allman, Greek Geometry from Thales to Euclid, Dublin: University Press,
18S9; and in " Hermathena," a series of papers on literature, science, and phi
losophy, by members of Trinity College, Dublin, Nos. 5, 7, 10-13, Dublin: 1878,
1881, 1884-1887. For his philosophy, cf. Zeller, Die Philos. d. Griech., 3d ed.,
1881, Vol. 3, pp. 774 sq., and Outlines, § 101 ; Hegel, Gesch. d. Philos., 2d ed.,
Vol. 3, pp. 01-79; Alfred William Benn, *The Greek Philosophers, Vol.2, pp.
358-300, London: Kegan Paul, Trench, & Co., 1882. The Philosophical and
Mathematical Commentaries on the First Book of Euclid's Elements, etc.,
were translated by Thomas Taylor, London, 1792, 2 vols. in 1, 4to. — TR.
NEW ESSAYS ON HUMAN UNDERSTANDING
BOOK II. — IDEAS
CHAPTER I
WHICH TREATS OF IDEAS IX GENERAL, AXD EXAMINES BY THE
WAY WHETHER, THE MIXD OF MAX ALWAYS THIXKS
§ 1. Ph. Having examined the question of innate ideas, let
us consider their nature and their differences. Is it not true
that the idea is the object of thought ?
Th. [I admit it, provided you add that it is an immediate
internal object, and that this object is an expression of the na
ture or the qualities of things. If the idea were the form of
thought, it would spring up and cease with the actual thought
to which it corresponds ; but being the object it may exist pre
vious to arid after the thoughts. External sensible objects are
only mediate because they cannot act immediately upon the
soul.1 God alone is the external immediate object. We might
say that the soul itself is its own immediate internal object ;
but it is this in so far as it contains ideas, or what corresponds
to things. For the soul is a little world,2 in which distinct
ideas are a representation of God, and in which confused ideas
are a representation of the universe.]
§ 2. Ph. We who suppose that at the beginning the soul is a
tabula rasa, void of all characters and without an idea, ask how
it comes to receive ideas, and by what means it acquires this
1 Cf. Book IV., chaps. 9 and 11. The opposition here set up between mediate
and immediate knowledge corresponds to Kant's a posteriori and a priori
knowledge. — TR.
2 Microcosm. — TR.
109
110 LEIBNITZ'S CRITIQUE OF LOCKE [UK. n
prodigious quantity of them ? To that question the reply in a
word is : From experience.
Tli. [This tabula rasa, of which so much is said, is in my
opinion only a fiction which nature does not admit, and which
is based only upon the imperfect notions of philosophers, like
the vacuum, atoms, and rest, absolute or relative, of two
parts of a whole, or like the primary matter1 which is con
ceived as without form. Uniform things and those which con
tain no variety are never anything but abstractions, like time,
space', and the other entities of pure mathematics. There is no
body whatever whose parts are at rest, and there is no sub
stance whatever that has nothing by which to distinguish it
from every other. Human souls differ, not only from other
souls, but also among themselves, although the difference is
not at all of the kind called specific. And. according to the
proofs which I believe we have, every substantial thing, be it
soul or body, has its own characteristic relation to every other;
and the one must always differ from the other by intrinsic
connotations. Xot to mention the fact that those who speak
so frequently of this tabula rasa after having taken away the
ideas cannot say what remains, like the scholastic philoso
phers, who leave nothing in their primary matter.1 You
may perhaps reply that this tabula rasa of the philosophers
means that the soul has by nature and originally only bare fac
ulties. But faculties without some act, in a word the pure
powers of the school, are also only fictions, which nature
knows not, and which are obtained only by the process of ab
straction. For where in the world will you ever find a faculty
which shuts itself up in the power alone without performing
any act? There is always a particular disposition to action,
and to one action rather than to another. And besides the
disposition there is a tendency to action, of which tendencies
there is always an infinity in each subject at once ; and these
tendencies are never without some effect. Experience is nec
essary, I admit, in order that the soul be determined to such
or such thoughts, and in order that it take notice of the ideas
which are in us ; but by what means can experience and the
senses give ideas ? Has the soul windows, does it resemble
tablets, is it like wax? It is plain that all who so regard the
i Mater ia Prima. — Tn.
CH. i] ON HUMAN UNDERSTANDING 111
soul, represent it as at bottom corporeal. You oppose to me this
axiom received by the philosophers, that there is nothing in the
soul ichich does not come from the senses. But you must except
the soul itself and its alt'ections. Nihil est in intellectu, quod
non faerit in sensu, excipe : nisi ipse intellectas. Kow the soul
comprises being, substance, unity, identity, cause, perception,
reason, and many other notions which the senses cannot give.
This view sufficiently agrees with your author of the Essay, who
seeks the source of a good part of ideas in the spirit's reflec
tion upon its own nature.
Pit. [I hope, then, that you will agree with this skilful
author that all ideas come through sensation or through re
flection, that is to say, from observations which we make either
upon objects exterior and sensible or upon the inner workings
of our soul.
Tli. [In order to avoid a discussion upon what has delayed
us too long, I declare to you in advance, sir, that when you
say that ideas come to us from one or the other of these causes,
I understand the statement to mean their actual perception,
for I think I have shown that they are in us before they are
perceived so far as they have any distinct character.
§ 9. Ph. [In the next place let us inquire when we must
say that the soul begins to perceive and actually to think of
ideas. I well know that there is an opinion which states that
the soul always thinks, and that actual thought is as inseparable
from the soul as actual extension is from the body. § 10. l>ut
I cannot conceive that it is any more necessary for the soul
always to think than for the body always to be in motion, per
ception of ideas being to the soul what movement is to the
body. That appears to me very reasonable at least, and I
would gladly know your view, sir, thereupon.
Th. You have stated it, sir. Action is no more connected
with the soul than with the body, a state without thought in
the soul and an absolute repose in the body appearing to me
equally contrary to nature, and without example in the world.
A substance once in action, will be so ahvays, for all the im
pressions remain and are merely mingled with other new ones.
Striking a body, we arouse therein or determine rather an
infinite number of vortices as in a liquid, for at bottom every
solid has a degree of liquidity and every liquid a degree of
112 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
solidity, and there are no means of ever stopping entirely these
internal vortices. Xow we may believe that if the body is
never at rest, the soul, which corresponds to it, will never be
without perception either.]
Ph. But it is. perhaps, a privilege of the author and conserve!*
of all things, that being infinite in his perfections, he never slum
bers nor sleeps. This is not granted to any finite being, or at
least not to such a being as is the soul of man.
Tti. [It is certain that we slumber and sleep, and that God
is exempt from both. But it does not follow that we have no
perception while asleep. Rather just the contrary is found to
be the case, if we consider it carefully.]
Ph. There is something in us which has the power to think ;
[but it does not thereby follow that it is always in action.]
Th. [Keal powers are never simple possibilities. They have
always tendency and action.
Ph. But this proposition — the soul always thinks — is not
self-evident.
Th. I do not say it is. A little attention and reasoning is
necessary to discover it ; the common people perceive it as little
as they do the pressure of the air or the roundness of the earth.]
Ph. I doubt if I thought last night ; this is a question of fact,
it must be decided by sensible experiences.
Th. [It is decided as it is proved, that there are imperceptible
bodies and invisible movements, although certain persons treat
them as absurd. There are also numberless perceptions little
noticed which are not sufficiently distinguished to be perceived
or remembered, but they become known through certain conse
quences.]
Ph. There was a certain author who raised the objection that
we maintain that the soul ceases to exist, because we are not
sensible of its existence during our sleep. But this objection
can arise only from a strange prepossession, for we do not say
that there is no soul in man because we are not sensible of its
existence during our sleep, but only that man cannot think
without being aware of it.
Th. [I have not read the book which contains this objection,
but it would not have been wrong merely to object to you that
it does not follow because the thought is not perceived, that it
ceases for that reason ; for otherwise it could be said for the
CH. i] OX HUMAN UNDERSTANDING 110
same reason that there is no soul during the time in which it
is not perceived. And to refute this objection it is necessary
to point out in particular the thought that it is essential to it
that it be perceived.]
§11. Ph. It is not easy to conceive that a thing can think
and not be conscious that it thinks.
Tit. There is, doubtless, the knot of the affair and the diffi
culty which has embarrassed able men. But here are the means
of extricating ourselves therefrom. We must consider that we
think of many things at a time, but we attend only to the
thoughts which are most distinct, and the process cannot go
on otherwise, for if we should attend to all, we would have to
think attentively of an infinite number of things at the same
time, all of which we feel and which make an impression upon
our senses. I say even more : there remains something of all
our past thoughts, and none can ever be wholly effaced. Xow
when we sleep without dreaming and when we are stunned by
some blow. fall, symptom, or other accident, an infinite number
of minute confused sensations take form within us, and death
itself can produce no other effect upon the souls of animals,
who ought, doubtless, sooner or later, to acquire distinct per
ceptions; for all goes on in an orderly way in nature. I admit,
however, that in this state of confusion, the soul would be with
out pleasure and without pain, for these are noticeable percep
tions.
§ 12. Ph. Is it not true that those with whom we have at
present to do. [i.e. the Cartesians, who believe that the soul
always thinks.] grant life to all animals, differing from man.
without giving them a soul which knows and thinks ; and that
these same (Cartesians) find no difficulty in saying that the soul
can think independently of a body ?
Tit. [For myself, I am of another opinion, for although I
agree with the Cartesians in their affirmation that the soul
thinks always. I am not agreed with them in the two other
points. 1 believe that the beasts have imperishable souls and
that human and all other souls are never without some body.
I hold also that God alone, as being an act us pxrxs. is wholly
exempt therefrom.]
Ph. If you had been of the opinion of the Cartesians, I should
have inferred therefrom, that the bodies of Castor or Pollux
i
114 LEIBNITZ'S CRITIQUE OF LOCKE [UK. 11
could be sometimes with, sometimes without a soul, though
being always alive, and the soul having the ability also to be
sometimes in one body and sometimes elsewhere, we might
suppose that Castor and Pollux had only a single soul, which
was active alternately in the body of these two men sleeping
and awake by turns ; thus it would be two persons as distinct
as Castor and Pollux could be.
Th. I, in my turn, will make you another supposition,
which appears more real. Is it not true that we must always
admit that after some interval or some great change, one may
fall into a state of general forgetfulness ? Sleidan l (they say),
before his death, forgot all he knew ; and there are many
other examples of this sad event. Suppose that such a man
became young again and learned all anew, will he be another
man on that account ? It is not then memory which, properly
speaking, makes the same man. Nevertheless, the fiction of a
soul which animates different bodies in turn, without concern
ing itself in one of these bodies with that which happens to it
in the other, is one of those fictions contrary to the nature of
things which arise from the imperfect notions of philosophers,
as space without body and body without motion, and which dis
appear when one penetrates a little deeper ; for you must know
1 John Sleidan, original name Philipsohn, c. 1506-1556, the annalist of the
Reformation. He was secretary for five years from 1536 to Cardinal dn Bellay,
minister of Francis I. of France. He was wont to copy all documents bearing
upon the Reformation to which he had access, and upon the suggestion of
Bucer to Philip of Hesse, after some delay was appointed, with the consent
of the heads of the Schmalkaldic League, historian of the Reformation, with a
salary and access to all necessary documents. He finished the first volume of
his great work in 1545. His work was then interrupted by a diplomatic mis
sion in a French embassy to Henry VIII. of England. While there he improved
every opportunity to collect materials for his history. In 1551 he was a mem
ber of the Council of Trent for Strassburg. On his return he was made Pro
fessor of Law at Strassburg, a position which enabled him to devote his whole
attention to his great work. It was finished for the press in 1554, and published
at Strassburg in 1555. It is entitled: Commentariorum de statu relit/ ionis et
reipnblicK Carolo Quinio, Cieaare, libri XXVI. The ed. of 1555 contained
only 25 books ; that of 1559 the 26th and an apology of Sleidan, written by
himself. The best edition is that of Francfort, 1785-86, 3 vols., 8vo. The work
is "the most valuable contemporary history of the times of the reformation,
and contains the largest collection of important documents." It is especially
noteworthy for its accuracy, impartiality, and purity of style. There are two
English translations, by John Daws, 1560, and (I. Bohnm, 1689. There are
also translations in other languages. (Jf. H. Baumgarten, lecher tileidanus
Leben und Briefwechsel, 1878; tileidans Briefwechsel, 1881. — TR.
CH. i] ON HUMAN UNDERSTANDING 115
that each soul preserves all its preceding impressions, and
cannot divide itself equally in the manner just mentioned; the
future in each substance is perfectly united to the past ; this
is what constitutes the identity of the individual. Memory,
furthermore, is not necessary, nor even always possible, because
of the multitude of present and past impressions which co-op
erate in our present thoughts, for I do not believe tha.t there
are in man thoughts of which there is not some effect at least
confused or some remnant mixed with subsequent thoughts. We
can forget many things, but we could also remember them long
after if we would recall them as we ought.
§ 13. Ph. Those who chance to sleep without dreaming can
never be convinced that their thoughts are active.
Th. [One is feebly conscious in sleep, even when it is dream
less. The process of waking up itself shows this, and the easier
you are awakened the more you are conscious of what goes on
without, although this consciousness is not always strong enough
to cause you to awake.]
§ 14. Ph. It appears very difficult to conceive that the soul
is thinking at this moment in a sleeping man and the next in
one awake, without remembering its thoughts.
Th. [Xot only is that easy to conceive, but also something
like it is observed every day that we are awake ; for we always
have objects which strike our eyes and ears, and, as a result,
the soul is touched also, without our taking notice of it, because
our attention is bent upon other objects, until this object becomes
strong enough to draw it to itself, by redoubling its action or by
some other means ; it is like a particular sleep with reference
to that object, and this sleep becomes general when our atten
tion ceases to regard all objects together. Division of attention,
in order to weaken it, is also a means of putting yourself to sleep.]
Ph. I learned from a man, who in his youth had applied him
self to study and had a tolerably felicitous memory, that lie
never had a dream until he had had the fever, from which he
had just recovered at the time he spoke with me, at the age of
twenty-five or twenty-six years.
Th. [I have also been tolj of a student, more advanced in
years, who never had a dream. But it is not upon dreams alone
that you must base the perpetuity of the soul's perception, since
I have shown how, even while asleep, it has some perception of
what goes on without.]
110 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
§ 15. P/i. To think frequently and not to preserve a single
moment the memory of your thought, is to think in a useless
manner.
Th. [All impressions have their effect, but all the effects are
not always perceptible ; when I turn to one side rather than to
the other, it is very often through a series of minute impressions
of which I am not conscious, and which render one movement
a little more uncomfortable than the other. All our unpre
meditated actions are the results of a concurrence of minute
perceptions, and even our customs and passions, which influ
ence so much our deliberations, come therefrom ; for these
habits grow little by little, and, consequently, without the
minute perceptions, we should not arrive at these noticeable dis
positions. I have already remarked that he who would deny
these effects in the sphere of morals, would imitate the poorly
taught class who deny insensible corpuscles in physics; and
yet I see that among those who speak of liberty are some who,
taking no notice of these unperceived impressions, capable of
inclining the balance, imagine an entire indifference in moral
actions, like that of the ass of Buridan 1 equally divided between
two meadows. Concerning this we shall speak more fully
later. I admit, however, that these impressions incline with
out necessitating.
Pit. Perhaps we might say that in the case of a man awake
who thinks, his body counts for something and that memory
is preserved by means of marks in the brain, but when he is
asleep the soul thinks apart by itself.
1 John Buridan, a celebrated Nominalist of the 14th century, the date of
whose birth and death is unknown. He studied at Paris under William of
Occam (died 1347) and was for many years Professor of Philosophy in the
University of Paris, and in 1327 its rector. In philosophy his only authority
was reason. In the third book, first question, of his Quassti'mea in dcfcm lihrox
ef/iif-orum Arixtotelis. 1489, he discussed in an "independent and interesting
manner" the question of the freedom of the will, reaching conclusions similar
to those of Locke. In his view the liberty possessed by the soul consists in
" a certain power of suspending the deliberative process, and determining the
direction of the intellect ; otherwise the will is entirely dependent on the view
of the mind, the last result of examination." The story of the ass as an illus
tration of the indeterminism of the wilhj" is not," as Sir William Hamilton
says (Reid, 8th ed., Vol. 1, p. 238, note) he has ascertained, " to be found in
his writings." On Buridan, cf. Ueberweg, Hist, of Philos., English transla
tion, Vol. 1, pp. 46r>-4M; Prantl, Gesch. d. Logik, Vol. 4, 14-38; Stockl, Gesch.
d. Philos. d. Mittelalters, Vol. 2, 1023-1028. — TK.
CH. i] ON HUMAN UNDERSTANDING 117
Tli. I am very far from saying that, since I believe there
is always an exact correspondence between the body and
the soul, and since I employ the impressions of the body
of which we are not conscious, whether awake or asleep, in
order to prove that the soul has in itself similar ones. I
maintain even that something goes on in the soul which cor
responds to the circulation of the blood and to ail the internal
movements of the viscera, of which we are never conscious
however, just as those who live near a water-mill do not per
ceive the noise it makes. In fact, if there were impressions
in the body during sleep or waking hours, by which the soul
was not touched or in any wise affected, limits would be given
to the union of the soul and of the body, as if corporeal
impressions required a certain form and size in order for the
soul to perceive them ; which is not at all tenable if the soul
is incorporeal, for there is no relation between an incorporeal
substance and this or that modification of matter. In a
word, it is a great source of error to believe that there is no
perception in the soul besides those of which it is con
scious.
§ 16. Ph. The greater part of the dreams which we remem
ber are extravagant and incoherent. We should then say that
the soul owes the power of rational thought to the body, or
that it retains none of its rational soliloquies.
Tli. [The body responds to all the soul's thoughts, rational
or not, and dreams have also their marks in the brain as well
as the thoughts of those who are awake.
§ 17. Ph. Since you are so sure that the soul is always
actually thinking, I wish you would tell me what the ideas
are which are in the child's soul before it is united to the body,
or just at the time of its union, before it has received any idea
by means of sensation.
Tli. It is easy to satisfy you by our principles. The soul's
perceptions correspond always naturally to the constitution of
the body, and when there are a multitude of movements con
fused and little distinguished in the brain, as happens in the
case of those who have little experience, the soul's thoughts
(following the order of the things) cannot be more distinct. Yet
the soul is never deprived of the help of sensation, because it
always expresses its body, and this body is always impressed
118 LEIBNITZ'S CRITIQUE OF LOCKE [UK. n
by its surroundings l in an infinite number of ways, but which
often give only a confused impression.
§ 18. Ph. But here is still another question which the
author of this Essay asks. I very much wish (says he) that
those who maintain so confidently that the soul of man or
(what is the same thing) man thinks always, would tell me
how they know it?
Th. [I do not know but that more confidence is necessary to
deny that anything goes on in the soul of which we are not
conscious ; for that which is perceivable must be composed of
parts which are not so, nothing can spring into being at once,
thought no more than motion. In short, it is as if some one
asked to-day how we know the insensible corpuscles.
§ 19. Ph. I do not remember that those who tell us that
the soul always thinks ever say that man always thinks.
Th. [I think that is because they understand their state
ment of the separated soul, and yet they voluntarily admit that
man always thinks during the union. For myself, who have
reasons for holding that the soul is never separated from the
entire body, I believe that we can state absolutely that man
always does and will think.]
Ph. To say that the body is extended without having parts,
and that a thing thinks without being conscious that it thinks,
are two assertions which appear equally unintelligible.
Th. [Pardon me, sir; I am obliged to tell you that when
you advance the statement that there is nothing in the soul of
which it is not conscious, you beg the question which has al
ready prevailed in all our former discussion, or you have been
desirous to use it to destroy innate ideas and truths. If we
agree to this principle, in addition to the fact that we believe
it contrary to experience and reason, we should surrender with
out reason to our feeling, which, I believe, I have rendered
sufficiently intelligible. But besides the fact that our oppo
nents, skilful as they are, have brought no proof of that which
they urge so often and so positively, it is easy to show them
the contrary ; i.e. that it is impossible for us always to think
1 Gerhardt reads: " frappe par les ambians d'une infinite de manieres, mais
qui souvent ne donnent qu'une impression confuse." Erdmann and Jacques
read: "frappe' par les autres, qui 1'environnent, d'une infinite de manieres,
mais qui souvent ne font qu'une impression confuse." — TR.
en. i] ON HUMAN UNDERSTANDING 119
expressly upon all our thoughts ; otherwise, the spirit would
reflect upon each reflection to infinity without ever being able
to pass to a new thought. For example, in my consciousness
of some present feeling, I should always think that I think,
and still think that I think of my thought, and thus to infinity.
But it is very necessary that I cease reflecting upon all these
reflections, and that there be at length some thought which is
allowed to pass without thinking of it ; otherwise, we should
dwell always upon the same thing.]
Ph. But would there not be as good ground for maintaining
that a man is always hungry, by saying that he can be hungry
without feeling it ?
Th. There is just the difference ; hunger has particular rea
sons which do not always exist. Nevertheless, it is true also
that even when you are hungry you do not think of it every
moment; but when you do think of it you feel it, for it is a
very marked disposition ; there is always irritation in the
stomach, but it is necessary for it to become very strong to
cause hunger. The same distinction ought always to be made
between thoughts in general and remarkable thoughts. Thus,
what appears to put a ridiculous construction upon our opinion,
serves to confirm it.]
§ 23. Ph. One can now ask, when man begins to have ideas
in his thought ? And it seems to me that the reply must be,
when he has some sensation.
Tit. [I am of the same opinion; but it is by a principle a
little peculiar, for I believe that we are never without thoughts,
and also never without sensation. I distinguish only between
ideas l and thoughts ; for we always have all pure or distinct
ideas independently of the senses ; but thoughts always corre
spond to some sensation.]
§ 25. But the mind is passive only in the perception of
simple ideas, which are the rudiments or materials of knowl
edge, while it is active when it forms complex ideas.
Th. [How can it be that the mind is passive merely with
regard to the perception of all simple ideas, since, accord
ing to your own admission, there are simple ideas whose per-
1 Gerhardt reads: " Je distingue seulement entre les idees et les pensees " ;
Erdmann and Jacques read: " Je distingue seulement entre sensations et
pensees." — Tit.
120 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
ception comes from reflection, and since the mind l gives itself
thoughts from reflection, for it is itself which reflects ?
Whether it can refuse them is another question, and doubtless
it cannot (refuse them) without some reason, which turns it
aside from them, when there is some occasion for it.]
Pit. [It seems that hitherto we have discussed ex profexso.
Xow that we are going to come to the detail of ideas, I hope
that we shall be more agreed, and that we shall differ only in
some particulars.]
Th. [I shall be delighted to see able men adopting the
views which I hold to be true, for they are adapted to improve
them and to show them in a good light.]
CHAPTER II
SIMPLE IDEAS
§ 1. Ph. I hope then that you will admit that there are
simple and complex ideas ; thus heat and softness in wax, and
cold in ice, furnish simple ideas, for the soul has a uniform
conception of them, which is not distinguishable into different
ideas.
Th. [I believe that we can affirm that these sense-ideas are
simple in appearance, because, being confused, they do not give
the mind the means of distinguishing their contents. In like
manner distant things appear round, because their angles can
not be discerned, although some confused impression of them
is received. It is manifest, for example, that green arises
from a mixture of blue and yellow ; thus it is possible to
believe that the idea of green is also composed of these two
ideas. And yet the idea of green appears to us as simple as
that of blue or that of warmth. So we are to believe that the
ideas of blue and warmth are not as simple as they appear. I
readily consent, however, to treat these ideas as simple ideas,
because at least our apperception does not divide them, but it
1 Gerhardt reads : " et que 1 'esprit se donne " ; Erdmann and Jacques read :
" et qu'au moins 1'esprit se donne," and since the mind at least gives itself.
— TR.
CH. in] ON HUMAN UNDERSTANDING 121
is necessary to proceed to their analysis by means of other
experiences and by reason, in proportion as they can be ren
dered more intelligible.1 And it is also seen thereby that
there are perceptions of which we are not conscious. For the
perceptions of ideas simple in appearance are composed of per
ceptions of the parts of which these ideas are composed, with
out the mind's being conscious of them, for these confused ideas
appear simple to it.]
CHAPTER III
OF IDEAS WHICH COME TO US BY ONE SEXSE ONLY
Ph. Xow we can arrange simple ideas according to the
means by which we perceive them, for that is done, 1, by
means of one sense only ; 2, by means of more than one sense ;
3, by reflection , or 4, by all the ways 2 of sensation as well as
by reflection. Thus of those which enter by a single sense
which is particularly adapted to receive them, light and colors
enter only by the eyes ; all kinds of noises, sounds, and tones
enter by the ears ; the different tastes by the palate ; and odors
by the nose. These organs or nerves carry them to the brain,
and if any one of these organs chance to be disordered, these
sensations cannot be admitted by any artificial gate. The
most considerable qualities belonging to the touch are cold,
heat, and solidity. The others consist either in the configura
tion of the sensible parts, as smooth and rough, or in their
union, as compact, hard, soft, brittle.3
Th. [I quite agree, sir, with what you say, although I may
remark that, according to the experiment of the late M.
Mariotte 4 upon the defect of vision with regard to the optic
1 Erdmann's and Jacques's texts of chap. 2 end here; Gerhardt's text adds
the following: " Et Ton voit encor par la qn'il y a des perceptions dont on ne
s'appercoit point. Car les perceptions des idees simples en apparence sont
composees des perceptions des parties dont ces idees sont composees, sans qne
1'esprit s'en appercoive, car ces idees confuses luy paroissent simples." — TK.
2 Locke's expression, rfiilox. Worku, Vol. 1, p. 227, Bonn's ed. — TR.
3 Locke uses these forms, instead of the more common abstract forms end
ing in -ness. Hence I have used them in the translation. — TR.
4 Edme Mariotte, a celebrated French physicist, born about 1020, died 1084.
He was in some sense the initiator of experimental physics in France. The
experiment here referred to, and the resulting discovery of the blind spot at
122 LEIBNITZ'S CRITIQUE OF LOCKE [BK. u
nerve, it seems to me that the membranes receive the sensa
tion rather than the nerves, and there is an irregular en
trance for the hearing and the taste, since the teeth and the
vertex assist in causing any sound to be heard, and that tastes
make themselves known to some extent through the nose, by
reason of the connection of these organs. But all that makes
no change in the foundation of things as regards the explica
tion of ideas. As for the qualities belonging to touch, you
can say that smoothness or roughness, hardness or softness,
are only modifications of resistance or solidity.]
CHAPTER IV
OF SOLIDITY
§ 1. Ph. You will doubtless agree that the idea of solidity
is caused by the resistance we find in a body to the en
trance of another body into the place it occupies until it has
left it. That which thus hinders the approach of two bodies
when they are moved one toward another I call solidity. If
any one finds it more to the purpose to call it impenetrability, 1
give my consent. But I believe that the term solidity bears
a more positive character. This idea seems most intimately
connected with and essential to body, and can be found only
in matter.
Tli. It is true that we find resistance in touch, when another
body reluctantly gives place to our own. and it is also true
that bodies dislike to occupy the same place. Many, how
ever, doubt whether this repugnance is invincible, audit is well
also to consider that the resistance which is found in matter is
derived in more than one way and by means of reasons quite
different. A body resists another either when it must leave
the place which it has already occupied, or when it fails to
enter the place into which it was ready to enter, because the
other tries to enter also, in which case it may happen that, the
one not yielding to the other, they stop or mutually repel each
the entrance of the optic nerve, was made in 1(5(38. An account of it is sjiven
in a short paper in the second volume of his collected works. (Eavres de
Mariotte, 2 vols., Leyden: 1717, 4to. — TR.
CH. iv] ON HUMAN UNDERSTANDING 123
other. The resistance is seen in the change of that (body) to
which resistance is offered, whether it loses its force, changes
its direction, or both happen at once. Now you can say in
general that this resistance arises from the repugnance which
two bodies have to occupy the same place, which may be
called impenetrability. Thus when one body makes an effort
to enter, it at the same time forces the other to attempt to
leave or to prevent its entrance. But that kind of incompati
bility which makes one or the other, or both together, yield,
being once assumed, there are several reasons besides the one
named which make one body resist another which endeavors
to compel its departure. They are either in it or in the neigh
boring bodies. There are two which are in itself ; one is pas
sive and constant, the other active and variable. The first is
what I call inertia,1 after Kepler 2 and Descartes, which impels
matter to resist motion, and which it is necessary to destroy
by force in order to move a body, supposing that there were
neither gravity nor adhesion. Thus a body which undertakes
to drive forward another, experiences for that reason this re
sistance. The other cause, which is active and variable, con
sists in the impetuosity of the body itself, which does not
yield without resistance at the moment its own impetuosity
carries it into a place. The same reasons reappear in the
neighboring bodies when the body which resists is unable to
yield without causing the others to yield also. But then a
new consideration comes in — viz.: compactness (fermete) or
the adhesion of one body to another. This adhesion3 makes
it impossible to move one body without at the same time mov
ing the other to which it adheres, and this causes a kind of
traction in reference to this other. This adhesion so acts thot,
even should we put aside inertia and manifest impetuosity,
there would be resistance ; for if space is conceived as tilled
with matter perfectly fluid, and if a single hard body were
placed within it, this hard body (supposing there were in the
fluid neither inertia nor impetuosity) wrill be moved therein
without finding any resistance; but if space were full of" little
1 Gerhardt reads " incertie ": evidently an error. — TR.
2 John Kepler, 1571-1 (>.'>(), one of the creators of modern astronomy. His
complete works were edited by Dr. Ch. Friseh, Joannis Kcpleri opera omnia,
8 vols., Frankfort: 1858-1 871. — TR.
3 Erdmaim and Jacques add " souvent," often. — TR.
124 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
cubes, the 'resistance which, the hard body would find, should
it be moved among the cubes, would come from the fact that
the little hard cubes, 011 account of their hardness or because
of the adhesion of their parts one to another, would with diffi
culty be separated as much as would be necessary to make a
circle of movement, and to fill up the place of the body moved
at the moment it departs. But if two bodies should enter at
the same time by the two ends into a tube open on both sides,
and should fill it to its capacity, the matter in this tube, how
ever fluid it be, would resist by its impenetrability alone.
Thus, in the resistance of which we are here treating, we have
to consider the impenetrability of bodies, inertia, impetuosity,
and adhesion. It is true that, in my opinion, this adhesion of
bodies arises from a more subtile motion of one body toward
another ; but, as this is a point which may be disputed, it must
not be assumed at first. And for the same reason we must
only assume at first an original, essential solidity, which makes
the place always equal to the body, that is to say that the in
compatibility, or, to speak more accurately, the non-consistence1
of bodies in the same place is a perfect impenetrability which
receives neither more nor less, since many maintain that sensi
ble solidity can arise from a repugnance on the part of bodies
to be found in the same place, but which will not prove to be
an invincible repugnance. For all the ordinary Peripatetics
and many others believe that the same matter can fill more or
less space, which phenomenon they call rarefaction or conden
sation, not in appearance only (as when water is squeezed from
a sponge), but rigorously, like the scholastic conception of the
air. I am not of this opinion ; but I do not think that I ought
at first to assume the opposite opinion, the senses, apart from
the reasoning faculty, not sufficing to establish this perfect im
penetrability, which I hold to be true in the order of nature,
but which is not learned by sensation alone. .And some one
may claim that the resistance of bodies to compression arises
from an effort of the parts to spread themselves when they
have not their entire liberty. For the rest the eyes aid
greatly in proving these qualities, coming to the assistance of
1 Leibnitz's word is " 1'mconsistence," and, as it is apparently technical, I
have decided to transfer it, merely changing the form of the negative in- to
non- to avoid ambiguity. — TR.
en. iv] OX HUMAN UNDERSTANDING 125
touch. And at bottom solidity, so long as it presents a dis
tinct idea, is conceived by pure reason, although the senses
furnish the reasoning faculty with the proof that it is in
nature.
§ 4. Ph. We are at least agreed that the solidity of a body
carries with it the tilling of the space it occupies in such a
way as absolutely to exclude every other body [if a space can
be found in which there was none before], while hardness [or
the consistence rather which some call compactness (fer-
mefa')], is a strong union of certain parts of matter, which
make up masses of a sensible size, so that the whole mass does
not easily change its form.
Th. [This consistence, as I have already remarked, is pre
cisely what makes it difficult to move one part of a body with
out the other, so that when one part is pushed, the other,
which is not pushed, and which does not fall within the line
of tendency, is nevertheless induced to go from that side by a
kind of traction; and, further, if this last part finds any obsta
cle which holds or pushes it back, it draws it along, or holds
back, also, the first part ; and this action is always reciprocal.
The same thing sometimes happens in the case of two bodies
which do not touch and which do not form a continuous body
whose parts are contiguous ; and yet, the one pushed compels
the other to go without pushing it, so far as the senses can
give us knowledge. Of this the animant,1 electrical attraction,
1 See Krauth-Fleming, Vocal). Philos. Sciences, pp. 28, 29, and 571, edition
of 1877, Xew York: Sheldon & Co., 1883. The animant is that which pos
sesses and imparts life. Together with its cognates animality, animalish,
animalist, used frequently by Cudworth. See Iiitcll. Synt., 514, " i't tit
Animans, that it be Animant, or endued with Life, Sense, and Understand
ing." Ibid., li)8. "But no Atheist ever acknowledged conscious animal/tu
to be a first principle in the -universe ; nor that the whole was governed by
any animalist, sentient, and understanding nature, presiding over it as the
head of it." The term being technical, and, with its cognates, more or less
current in the seventeenth century, it seemed best to retain it, denning and
illustrating as above. Its meaning is, I think, sufficiently evident. It is to
be noticed, however, that Erdmann, in his Error es Typoyr aphid, prefixed
to his edition, reads aimant instead of animant. Jacques's text also has
«im<(nt. The translation would then be: The loadstone or rnaf/net ; and
Schaarschmidt, following this reading, renders it " der Magnet," in his German
translation of the Noureaity. Esscris, in J. H. v. Kirchmann's Philos. BibliotJiek,
Berlin, 1873. As I translate on the basis of Gerhardt's text I retain his read
ing and its translation, with the note explaining the term, although at the
present writing the reading of Erdmann and Jacques seems more congruous
with the context, and so more likely to be the true one. — TB.
126 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
and that which was formerly ascribed to the fear of a vacuum,
furnish examples.]
Ph. It seems that, in general, hard and soft are names which
we give to things solely as related to the particular constitu
tion of our bodies.
Tli. [But then many philosophers would not ascribe hard
ness to their atoms. The notion of hardness does not depend
upon the senses, and its possibility can be conceived by the
reason, although we are further convinced by the senses that
it is actually found in nature. I should, however, prefer the
word compactness — fermete (if I were allowed to use the word
in this sense) — to that of hardness, for there is some compact
ness even in soft bodies. I seek even a more suitable and
general term, like consistence or cohesion.' Thus I would
oppose hard to soft, solid to fluid, for wax is soft, but, unless
melted by heat, it is not fluid and preserves its bounds ; and
in fluids even there is ordinarily cohesion, as is shown in drops
of water and of mercury. I am also of opinion that all bodies
have some degree of cohesion, as I also believe that there are
none which do not have some fluidity, and whose cohesion is
not capable of being overcome ; so that, in my opinion, the
atoms of Epicurus,1 whose hardness is supposed to be invinci
ble, cannot occur any more than the subtile, perfectly fluid
matter of the Cartesians. But this is not the place to justify
this opinion or to explain the rationale of cohesion.
Ph. The perfect solidity of bodies seems to be justified by
experiment. For example, water incapable of yielding, passed
through the pores of a hollow globe of gold, in which it was
confined, when this globe was put under pressure in Florence.
Tli. [There is something to be said as to the inference which
you draw from this experiment, and from what happened in
the case of the water. The air as well as the water is a body,
which is compressible at least ad sensum, and those who would
maintain a complete rarefaction and condensation will say that
water is already too compressed to yield to our machines, as
air very much compressed would resist also a further compres
sion. I admit, however, on the other hand, that if any slight
change should be noticed in the volume of the water, it might
be ascribed to the air which is enclosed in it. Without enter-
1 Epicurus, December, 312, or January, 3il-270 B.C. — TB.
CH. iv] ON HUMAN UNDERSTANDING 127
ing now into the discussion whether pure water is not itself
compressible, as it is found that it is dilatable when it evapo
rates, I am, nevertheless, decidedly of the opinion of those who
believe that bodies are perfectly impenetrable, and that there
is, save in appearance, neither condensation nor rarefaction.
But this kind of experiment is as little capable of proving this
as the tube of Torricelli l or the machine of Guerike - are suffi
cient to prove a perfect vacuum.'1
§ o. Ph. If the body were strictly capable of rarefaction
and compression, it might change in volume or extension, but
that not being so, it will be always equal to the same space ;
and, moreover, its extension will be always distinct from that
of space.
Tli. [The body might have its own extension, but it does not
thereby follow that it would be always determinate or equal
to the same space. Nevertheless, although it may be true that
in the conception of body something besides space is conceived
of, it does not thereby follow that there are two extensions —
that of space and that of body ; for it is as when in conceiving
several things at once, one conceives something besides the
number, viz. : res numerator; and, moreover, there are not two
multitudes, the one abstract — i.e., that of number; the other
concrete — i.e., that of the things enumerated. Likewise one
can say that it is not necessary to think of two extensions —
the one abstract, of space, the other concrete, of body, the con-
1 Evangelista Torricelli, 1(508-104:7, a celebrated Italian physicist and mathe
matician, the inventor of the mercurial barometer, long called the "Torricel
lian tube." He had a controversy with Roberval (vi<L ante, p. 107 and note) as
to the discovery of the quadrature of the cycloid. Torricelli found the area of
the curve, and furnished the demonstration of it, which he published in a tract,
De mot n fjracium notaraliter accelerato in his Opera yeonietrica, Florence,
1644.— TR.
'2 Otto von Guerike, 1 (502-1 f 580, a German physicist, who devoted himself
especially to experimenting upon the vacuum, and who, after many attempts,
finally, in 1(554, hit upon an air machine, which enabled him to undertake
a series of experiments upon the different effects of vacuum. His labors and
principal observations have been published under the title, Ej'perimenta nova,
ut vorant, Mac/deburffica, de vai-no $j->atio. etc., Amsterdam, 1(572. — TR.
3 Descartes maintained the impossibility of a vacuum. Cf. Prin. Philos., II.,
§ 1C; English translation by John Veitch, LL.D., The Method, Meditations,
and Selections from the /Vm<"?/>/'-.s of Descartes, etc., 8th ed., p. 241, Edin
burgh : William Blackwood & Sons, 1881: also rid. mite, p. K>, and the fifth
letter to Samuel Clarke, § :U, Gerhardt, Vol. 7, p. WO; Erdmaim, p. 706, b:
translation, Duncan, Philos. IVorks of Leibnitz, p. 2152. — Tit.
128 LEIBNITZ'S CRITIQUE OF LOCKE [UK. n
crete existing as such only through the abstract. And as
bodies pass from one part of space to another — i.e., change
order among themselves — things also pass from one part of
the order or of a number to the other,, when, for example, the
first becomes the second and the second the third, etc. In
fact, time and space are only kinds of order/ and in these
orders the vacant place (which in relation to space is called
vacuum), if there were any, would show the possibility only of
that which is lacking together with its relation to the actual.
Ph. I am nevertheless very glad that you agree with me
that matter does not change in volume. But you seem to go
too far, sir, in not recognizing two extensions, and you re
semble the Cartesians, who do not distinguish space from mat
ter.- Xow it seems to me that if a class is found who, not
having these distinct ideas (of space and of solidity which fills
it), blends them and makes of the two one only, we cannot see
how these persons can converse with others. They are like a
blind man who, when another man speaks to him of scarlet,
thinks it resembles the sound of a trumpet.
Th. [But I hold at the same time that the ideas of exten
sion and solidity, like that of scarlet-color, do not consist in an
I know not ichat.3 I distinguish extension and matter, contrary
1 Cf. Letter toDes Bosses, June If), 1712, Gerharrlt, Vol. 2, p. 450; Erdmaini,
p. 682, b: 4i Spatium tit ordo coexistentiuni phaenomenorum, ut tenipus succes-
sivorum," i.e. " Space is the order of co-existing, as time of successive phe
nomena "; also the letters to Clarke, Gerhardt, Vol. 7, pp. 345 sq.; Erdmann,
pp. 74(3*2., translation, Duncan, Philos. Works of Leibnitz, pp. 238 sq.; Kant,
Kritik f.l. r. Vernunft, Erst. Th., Absch. 1 und 2, §§ 2-7, and translations of
Max Miiller, and Watson in The Philoxoph;/ of Kant, an contained in extracts
from ftis oirn writi/i;/s. New York: Macmillan & Co., 1888. — TR.
- Cf. Descartes, Prin. Philos. II., §§ 8-15; Veitch's translation, pp. 236-240.
-TR.
3 Leibnitz's expression is " un je ne say qiioi." Schaarschmidt trans
lates it " ein undenkbares Eticas." It seems to be equivalent to an indef
inite somewhat which is the ultimate essence of things, and which is the
cause of, and by differentiation becomes, the particular. Leibnitz, then,
means to say that the ideas of extension and solidity are distinct. Cf. John
Dewey, Ph.D., Leibniz's New Essays concerninr/ the Human Understanding,
a Critical Exposition, p. 134. As applied to personal beings, it seems to be
equivalent to the "unconscious presentations" — i.e. "the dark side of the
soul-life," " the proper basis of Individuality." " Genius, disposition, feeling,
are the terms by which a later time has designated what Leibnitz calls the
je ne sais quoi, whereby every one is preformed by nature to something par
ticular " (" Ganz wie bei dem blossen Monaden ihre individuelle Beschaffen-
heit in dem Momente der Schranke, der mater ia prima, lag, ganz so werden
en. v] ON HUMAN UNDERSTANDING 129
to the view of the Cartesians. Still I do not believe that there
are two extensions ; and since those who dispute over the dif
ference between extension and solidity are agreed on several
truths upon this subject and have some distinct notions, they
can find therein the means of extricating themselves from their
disagreement ; thus the assumed difference upon ideas ought
not to serve as a pretext for eternal disputes, although I know
that certain Cartesians, otherwise very able, are accustomed
to intrench themselves in the ideas which they pretend to
have. But if they would avail themselves of the means which
I have before given for recognizing ideas true and false, and
of which we shall speak also in the sequel, they would retire
from a position which is not tenable.
CHAPTER V
OF SIMPLE IDEAS WHICH COME BY DIFFERENT SEXSES
Ph. The ideas, the perception of which conies to us from
more than one sense, are those of space, or extension, or fig
ure, of motion and rest.
Th. [The ideas which are said to come from more than one
sense, like those of space, figure, motion, rest, are rather from
common-sense, that is to say, from the mind itself, for they
are ideas of the pure understanding, but related to externality,
and which the senses make us perceive ; they are also capable
of definition and demonstration.]
hier diese unbewussten Yorstellungen, d. h. Avird die dunkle Seite des Seelen-
lebens, als der eii;entlirhe Grand der Individuality bestinnnt. Genius,
Gemiith, Gefiilil sind die Worte, niit denen eine spiitere /eit das bezeiehnet
hat, was Leibnitz das j<> n<> .s-rr/.s- qtini nennt, wodurrh Jeder von Xatur zu
etwas Besondereni praformirt ist." Erdmann, Gnniclritts d. Gext-h. d. Philox.,
3te Autia.u-e 2te Bd. § 288, 5, s. 1(51. Berlin, 1878 : English translation. Vol. 2,
p. T.il, London: Swan Sonnenschein & Co., 188!)). Cf. also Leibnitz, New
Esstiifa, Preface, ri<1. mitr, pp. 47 sq., Book II., chap. 1, § l.~>, Th., xq., and
Erdinann's exposition of the same, o/>. cit., s. 100, 101. Also Professor Dewey's
most excellent work cited above. — TR.
130 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
CHAPTER VI
OF SIMPLE IDEAS WHICH COME BY REFLECTION
Ph. The simple ideas which come by reflection are the ideas
of the understanding and of tie will [for we ourselves per
ceive them in reflecting upon ourselves.]
Th. [It is doubtful if all these ideas are simple, for it is
clear, for example, that the idea of the will includes that of
the understanding, and that the idea of motion contains that
of figure.
CHAPTER VII
OF IDEAS WHICH COME BY SENSATION AXD REFLECTION
§ 1. Ph. There are some simple ideas which make themselves
perceived in the mind by all the avenues of sensation and by
reflection also — viz.: pleasure, pain, power, existence, unity.
Th. [It seems that the senses cannot convince us of the exist
ence of sensible things without the aid of the reason. Thus I
should think that the idea1 of existence comes from reflection.
That of power also and of unity come from the same source,
and are of a wholly different nature from the perceptions of
pleasure and pain.]
CHAPTER VIII
OTHER CONSIDERATION'S UPON SIMPLE IDEAS
§ 2. Ph. What shall we say of ideas of privative qualities?
It seems to me that the ideas of rest, darkness, and cold are as
positive as those of motion, light, and heat. Nevertheless, in
proposing these privations as the causes of privative ideas I
follow the common view; but in the main it will be difficult
1 The French is " la consideration de 1'existence." — TR.
CH. vin] ON HUMAN UNDERSTANDING 131
to determine whether there is really any idea which arises
from a privative cause until it has been determined whether
rest any more than motion is a privation.
Th. [I had not believed that we could have reason to doubt
the privative nature of rest. It suffices it that motion in the
body be denied, but .it does not suffice for motion to deny rest,
and it is necessary to add something more to determine the de
gree of motion, since it receives materially more or less, while
all rest is equal. It is another thing when we speak of the
cause of rest, which must be positive in the secondary l matter
or mass. I should furthermore regard the very idea of rest as
privative — i.e., that it consists only in negation. It is true
that the act of denial is positive.]
§ 9. Ph. The qualities of things being the faculties they have
of producing in us perception of ideas, it is well to distinguish
these qualities. They are primary and secondary. Extension,
solidity, figure, number, mobility are the original qualities
inseparable from body which I call primary. § 10. But I call
1 Leibnitz constantly distinguishes between primary and secondary matter.
Primary matter is the primitive passive power belonging to each separate
being as such, by which it is distinguished from God and in which is grounded
the possibility of representing itself as different. It is essential to and insepa
rable from the &u±elechy.or principle of actiyity^jwhich it completes, the two
united producing^the ^perfect substance or monad. By itself it is a^fmre
"attraction or~potentiality, and noTa'substance. Tt is equivalent to confused
ideas, thus to an imperfect manifestation or phenomenon of spirit — since all
matter is ultimately spirit or has its final reason or source in spirit — but a
potentiality of spirit capable sometime of realizing perfectly all its intrinsic,
but now latent, activity. Secondary matter is a mass resulting from the union
of many monads or complete substances, each having its own primary matter
and its own entelechy, with their derived forces, activities, receptivities. It
is not, however, a substance ; and its extension resulting from the union of
non-extended simple substances is only phenomenal, though not on that
account unreal, being due to our confused perception, and consisting in the
impenetrability, resistance, or inertia of the monad on its passive .side ; an
extension which will disappear when the activity of the monad becomes pure
and perfect. Of. Letters to Tolomei, Dec. 17, 1705, Gerhardt, Vol. 7, pp. 407-
468; Des Bosses, March 11, Oct. 16, 1706, March 16, 170!), Gerhardt, Vol. 2,
pp. 304, 324, 368 ; Erdmann, pp. 435, 440, 456; De aniwa brtttonim, 1710, G. 7,
328; E. 463; Letters to Rud. Christ. Wagner, June 4, 1710, G. 7, 528, E. 465;
translation, Duncan, Philos. Works of Leibnitz, p. 190 sq. • Bierling, Aug. 12,
1711, G. 7, 500-502, E. 677-678 ; Remond, Nov. 4, 1715, G. 3, 056-660 ; E. 735-
737 ; Feb. 11, 1715, § 4 (reply to Remond's fourth difficulty stated in his letter to
Leibnitz, Jan. 9, 1715), G. 3, 63(5, E. 725 ; also the writing dated July, 1714, and
first published by Gerhardt, 3, 622-624. Of. also Erdmann, Grund. d. Gesch.d.
Philos., '3d ed., § 288, 2, 3 ; Dewey, Leibnitz, New Essays, chaps. 7 and 8. — TR.
132 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
secondary qualities the faculties or powers of bodies to produce
certain sensations in us, or certain effects in other bodies, as
the fire, for example, produces a certain effect in the wax when
melting it.
Th. [I think we can say that when the power is intelligible,
and can be distinctly explained, it should be reckoned among
the primary qualities ; but when it is only sensible and gives
only a confused idea, it should be put among the secondary qual
ities.^
§ 11. Ph. These primary qualities show how bodies act upon
one another. Now, bodies act only by impulse, at least so far
as we can conceive the process, for it is impossible to under
stand how bodies can act upon what they do not touch, which
is equivalent to imagining that they can act where they are
not.
Th. [I am also of the opinion that bodies act only by impulse.
Yet, there is some difficulty in the proof of what I have just
heard ; for attraction sometimes occurs without contact, and we
can touch and draw without any visible impulse, as I have
shown above 1 in speaking of hardness. In the case of the atoms
of Epicurus, the one part pushed would draw the other with
it, and would touch it in putting it in motion without impulse.
And in the case of attraction between contiguous things we
cannot say that the one which draws with itself acts where it
is not. This reason would militate only against attractions
from a distance, as would be the case in reference to what are
called vires centripetal advanced by some scholars.]
§ 13. Ph. Xow, certain particles, striking our organs in a cer
tain way, cause in us certain sensations of colors or tastes or
other secondary qualities which have the power of producing
these sensations. And it is no more difficult to conceive that
God can attach such ideas (as that of heat) to motions, with
which they have no resemblance, than it is difficult to conceive
that he has attached the idea of pain to the motion of a piece
of iron which divides our flesh; which motion the pain in no
manner resembles.
Th. [It is not necessary to suppose that ideas like those of
color or of pain are arbitrary and without relation or natural
connection with their causes ; it is not the custom of God to
1 Cf. Bk. II., Chap. 4, § 4, Th., ante, p. 125, *?. — TR.
CH. vin] ON HUMAN UNDERSTANDING 133
act with so little order and reason. I should rather say that
there is a kind of resemblance, not complete and, so to speak,
in terminis, but expressive, or a kind of orderly relation, as an
ellipse, and even a parabola or hyperbola resemble in some
sense the circle of which they are a projection upon a plane,
since there is a certain exact and natural relation between
what is projected and the projection which is made, each point
of the one corresponding by a certain relation to each point of
the other. This the Cartesians do not sufficiently consider,
and for once you have deferred to them more than has been
customary with you, and without reason for so doing.]
§ 15. Ph. I tell you what appears to me, and the appear
ances are that the ideas of the primary qualities of bodies
resemble these qualities, but the ideas produced in us by the
secondary qualities resemble them in no way.
Th. [1 have just shown how there is resemblance or exact
relation in respect to the secondary as well as the primary
qualities. It is certainly reasonable that the effect correspond
to its cause ; and how assert the contrary, since you know dis
tinctly neither the sensation of blue (for example) nor the
motions which produce it ? It is true that pain does not
resemble the motion of a pin, but it may very well resemble
the motions which this pin causes in our body, and represent
these motions in the soul, as I have no doubt it does. It is
also for this reason that we say that the pain is in our body
and not that it is in the pin ; but we say that the light is in the
fire, because there are in the fire motions which are not dis
tinctly sensible apart from it. but whose confusion or con
junction becomes sensible, and is represented to us by the idea
of light.
§ 21. Ph. But if the relation between the object and the
sensation be natural, how can it be, as we notice in fact, that
the same water may appear warm to one hand and cold to the
other ? which shows that the heat is no more in the water
than the pain is in the pin.
Th. [This proves all the more that heat is not a sensible
quality or power of making itself felt absolutely all at once,
but that it is relative to the suitable organs ; for a particular
motion in the hand may be mixed with it and change its appear
ance. Light, furthermore, does not make itself evident to
134 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
badly constituted eyes, and when they are themselves filled
with a great light, they are insensible to a less. Even the
primary qualities (according to our classification) — for ex
ample, unity and number — may not appear as they should;
for, as Descartes has already stated, a globe touched by the
fingers in a certain way appears double, and mirrors or glasses
cut in facets multiply the object. It does not then follow that
what does not always appear the same is not a quality of. the
object, and that its image does not resemble it. And as for
the heat, when our hand is very warm, the medium heat of the
water does not make itself felt, and modifies rather that of
the hand, and consequently the water appears to us cold ; as
the salt water of the Baltic Sea mixed with the water of the
Sea of Portugal1 would lessen its specific saline quality,
although the former be itself salt. Thus, in any case, we can
say that the heat belongs to the water of a bath, although it
may appear cold to any one, as honey is called absolutely
sweet, and silver white, although the one appears bitter, the
other yellow to some diseased persons, for the classification is
made upon the basis of the most common (conditions) ; and
yet it remains true that, when the organ and the medium are
constituted as they should be, the internal motions and the
ideas which represent them to the soul resemble the motions
of the object which cause color, heat, pain, etc., or, what is
here the same thing, express it by means of a relation suffi
ciently exact, although this relation does not distinctly appear
to us, because we cannot disentangle this multitude of small
impressions either in our soul or our body or in what is with
out.
§ 24. Ph. We consider the qualities which the sun has of
blanching or melting wax or hardening mud only as simple
powers, without thinking of anything in the sun correspond
ing to this blanching, softness, or hardness ; but heat and light
are commonly regarded as real qualities of the sun. Properly
considered, however, these qualities of light and heat which in
me are perceptions are not in the sun in any other manner
than the changes produced in the wax when it is blanched or
melted.
1 Obsolete name for that part of the Atlantic which washes the coast of
Portugal. — TR.
CH. ix] ON HUMAN UNDERSTANDING 135
Th. [Some have pushed this doctrine so far that they have
desired to persuade us that if any one could touch the sun he
would find there no heat. The counterfeit sun which makes
itself felt in the focus of a mirror or a burning-glass may disa
buse people of this notion. But as to the comparison between
the power of heating and that of melting, I dare affirm that if
the melted or blanched wax had feeling, it would feel some
thing similar to what we feel when the sun warms us, and
would say, if it could, that the sun is warm, not because its
whiteness resembles the sun — for when faces are tanned in
the sun their brown color should likewise resemble it — but
because there are in the wax motions which are related to
those in the sun which cause them ; its whiteness may come
from another cause, but not the motions which it has had in
receiving it (whiteness) from the sun.]
CHAPTER IX
OF PERCEPTION
§ 1. Ph. Come we now to the ideas of reflection in particu
lar. Perception is the first faculty of the soul which is occu
pied with our ideas. It is also the first and simplest idea
which we receive by reflection. Thought signifies often the
mind's working upon its own ideas, when it acts and considers
a thing with a certain degree of voluntary attention : but in
what we call perception the mind is ordinarily purely passive,
not being able to avoid perceiving what it actually perceives.
Th. [We might perhaps add that the animals have percep
tion, and that it is not necessary that they have thought, that
is to say, that they have reflection or \vhat may be its object.
We ourselves also have minute perceptions of which we are not
conscious in our present state. It is true that we might very
well perceive them ourselves, and reflect upon them, if we
were not turned aside by their multitude, which distracts our
mind, or if they were not effaced, or rather obscured, by
greater ones.
§ 4. Ph. I admit that when the mind is strongly occupied
136 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
in contemplating certain objects it does not perceive in any
way the impression which certain bodies make upon the organ
of hearing, although the impression may be quite strong ; but
no perception arises therefrom if the soul takes no cognizance
thereof.
Th. [I should prefer to distinguish between perception and
consciousness (s'appercevoir).1 The perception of light and
color, for example, of which we are conscious, is composed of
many minute perceptions, of which we are not conscious ; and
a noise which we perceive, but of which we take no notice,
becomes apperceptible by a little addition or increase ; for if
what precedes make no impression upon the soul, this little
addition would also make none, and the whole would make
no more. I have already touched upon this point (Ch. II,2 of
this book, §§ 11, 12, 15, etc.)].
§ 8. Ph. It is proper to remark here that the ideas which
arise from sensation are often altered by the mental judgment
of grown persons without their perceiving the fact. A flat
circle with various light and shade represents the idea of a
globe of uniform color. But, as we are accustomed to distin
guish the images of bodies and the changes of the reflections
of light according to the figures of their surfaces, we put in the
place of what appears to us the cause the image itself, and
confuse the judgment with the appearance.
Th. Xothing is truer, and this it is which gives to painting
the means of deceiving us by the artifice of a very extended
perspective. When bodies have flat surfaces, they can be rep
resented without employing shadows by giving only their con
tours and by simply making pictures after the fashion of the
Chinese, but better proportioned than theirs. The same
1 Cf. Leibnitz, Principes de In nature et tie la f/race f on tie's en raj son, § 4.
" It is well to make a distinction between the perception, which is the internal
condition of the monad representing external tilings, and ctppwpptinn, which
is consciousness or the reflective knowledge of this internal state: the latter
not being given to all souls, nor at all times to the same soul." For the
entire piece, which is a brief statement of his philosophical system prepared
by Leibnitz himself, with the greatest care, about 1714, rf. Gerhardt, Vol. 0,
pp. 508-(>0(>; Erdmann, pp. 714-718; translation, Duncan. Phil™. Works nf
Leibnitz, pp. 2011-217, and note (>fi. p. 387 op. df. Also Hamilton's Reid, Stii
ed., Vol. 2, p. 877, note, and Krautli-Floming. Vnt-nh. PhiJos., ed. of 1877,
articles "Apperception," p. 38, "Consciousness." pp. 100-113.013, "Percep
tion," pp. 37:?-374. 807-800, "Perceptions (Obscure)," pp. 374-370. — TR.
2 This should be chap. 1, I think. — TR.
en. ix] OX HUMAN UNDERSTANDING 137
custom is observed in designing medals, in order that the
draughtsman may be less likely to depart from the precise
form of the antique. But we cannot distinguish exactly by
means of the design the interior of a circle from the interior of
a spherical surface bounded by this circle without the aid of
shadows, the interior of each having neither points distin
guished nor distinguishing features, although there is, however,
a great difference which ought to be indicated. Desargues l
has accordingly given precepts Upon the force of tints and
shades. When, then, a painting deceives us there is a double
error in our judgments; for first we put the cause for the effect,
and think we see immediately the cause of the image, in which
we resemble a little a dog who barks at a mirror ; for, properly
speaking, we see only the image, and we are affected only by
the rays of light. And since the rays of light require time (how
ever little it be), it is possible for the object to be destroyed in
this interval, and for it no longer to exist when the ray reaches
the eye, and that which no longer exists cannot be the object
present to the sight. In the second place, we further deceive
ourselves when we put one cause for another, and think that
what comes only from a flat picture is derived from a body, so
that in this case there is in our judgments all at once a me
tonymy and a metaphor ; for even the figures of rhetoric pass
into sophisms when they impose on us. This confusion of the
effect with the cause, whether true or false, often enters into
our judgments, moreover, upon other things. Thus we feel
our bodies, or what touches them, and we move our arms by
means of an immediate physical influence, which we think
1 Gaspare! Desargues, 1503-16(52, a French geometer and engineer, a friend
of Descartes, Gassendi, Pascal, and Roberval, who wrote on the application of
geometry to the arts as well as on geometry itself. These writings have been
lost and their titles are known only through the engraver Bosse. Of his
Method? umversell? de mettre en perspective des objects donnes reellement,
on en derix, arec lenrs proportions, metres, eloiynments, sons employer
aurun point qui soit hors du champ de roiivrrtf/e, 1030 or 1636, Descartes thus
speaks in a letter to Mersenne ("written toward the end of April, 1(537,"
according to Cousin, fEwws de Descartes, Vol. 6, pp. 250-250, Paris : 1824-
1826), "Je n'ai recu qne depuis pen de jours le petit livre in folio, qni traite
de la perspective: il n'est pas a desapprouver, outre que la curiosite et la
nettete du langage de son auteur sont a estimer," I received only a few
days ago the little book in folio treating of perspective: it is not to be con
demned : further the exactness and perspicuity of the author's language are to
be admired. — TR.
138 LEIBNITZ'S CRITIQUE OF LOCKE [HK. n
constitutes the connection of the soul with the body, while in
truth we feel and change in that way only what is in us.
Ph. I will at this time propose to you a problem which the
learned Mr. Molyneux,1 who employs so profitably his excel
lent genius in the promotion of the sciences, communicated to
the illustrious Mr. Locke. Here it is nearly in his own
terms : Suppose a man blind from birth, now grown up, who
has learned to distinguish by touch a cube from a globe of the
same metal, and almost of* the same size, so that when he
touches the one or the other he can tell which is the cube and
which the globe. Suppose that the cube and the globe being
placed upon the table, this blind man comes to enjoy his sight.
The question is, if in seeing them without touching them he
could distinguish them, and tell which is the cube and which
the globe. I pray you, sir, tell me what is your opinion upon
the matter.
Th. I ought to give some time to thought upon this ques
tion, which appears to me quite curious : but since you press
me for an immediate reply, I would venture to say between
ourselves that I think that supposing the blind man knows
that these two figures which he sees are those of the cube and
the globe, he could distinguish them and say, without touch
ing. This is the globe, this the cube.
Ph. I fear lest it may be necessary to put you in the crowd
of those who have failed to answer Mr. Molyneux ; for he sent
word in the letter which contained this question, that, having
proposed it upon the occasion of Mr. Locke's Essay on Under
standing to different persons of very penetrating minds, he
had found scarcely one among them who at once gave such a
reply upon that point as he thinks should be made, although
they were convinced of their error after having heard his
reasons. The reply of this penetrating and judicious author
is negative ; for (he adds) while this blind man has learned
by experience of some kind the globe and the cube as they
affect his touch, he does not, however, yet know that what
affects the touch in such or such manner must strike the eyes
1 William Molynenx, 1650-1098, an eminent mathematician. He founded in
Dublin, in January, KiS4, a Philosophical Society on the model of the Royal
Society at London. His principal work, l)i«}itrica Nova, in two parts, was
published at London in lo(J2-170'J, in 4to. — TB.
CIL ix] ON HUMAN UNDERSTANDING 139
in such or such manner, nor that the projecting angle of the
cube, which presses his hand in an unequal manner, must
appear to his eyes as it appears in the cube. The author of
the Essay declares himself at once of the same opinion.
Tli. Perhaps Mr. Molyneux and the author of the Essay are
not so far from my opinion as at first appears, and the reasons
for their view, contained apparently in the letter of the for
mer, who has employed them with success in order to convince
men of their error, have been purposely suppressed by the
latter in order to give more exercise to the minds of his
readers. If you will weigh my reply, you will find, sir, that
I have placed therein a condition which can be considered as
comprised in the question — viz. : that the question is that of
distinguishing alone, and that the blind man knows that the
two figured bodies, which he should distinguish, are there, and
that thus each of the appearances which he sees is that of the
cube or that of the globe. In this case it appears to me
beyond doubt that the blind man who ceases to be such can
distinguish them by the principles of reason, united with that
sense-knowledge with which touch has before furnished him.
For I do not speak of that which he will do perhaps in fact
and immediately, dazzled and confused by the novelty, or from
some other cause little accustomed to draw inferences. The
basis of my view is that in the globe there are no points dis
tinguished by the side of the globe itself, all there being level
and without angles, while in the cube there are eight points
distinguished from all the others. If there were not this
means of discerning the figures, a blind man could not learn
the rudiments of geometry by touch. But we see that those
born blind are capable of learning geometry, and have indeed
always certain rudiments of a natural geometry, and that
most often geometry is learned by sight alone, without the
use of touch, as indeed a paralytic or other person to whom
touch has been almost denied might and even must do.
And these two geometries — that of the blind man and that of
the paralytic — must meet and agree, and indeed return to the
same ideas, although there are no common images. This again
shows how necessary it is to distinguish images from exact
ideas, which consist in definitions. It would really be very
interesting and instructive to make a complete examination of
140 LEIBNITZ'S CRITIQUE OF LOCKE [UK. n
the ideas of a man born blind, to understand the descriptions
he makes of figures. For he may come to this, and he may
even understand the doctrine of optics, so far as it is depend
ent upon distinct and mathematical ideas, although he could
not attain to a conception of dair-confus, that is to say, the
image of light and of colors. This is why a certain one born
blind, after having attended lessons in optics, which he
appeared fully to understand, replied to some one who asked
him what he thought light was, that he thought it must be
something pleasant like sugar. It would likewise be very
important to examine the ideas which a man born deaf and
dumb may have of things not figured, whose description we
usually have in words, and which he must have in a manner
wholly different from, though it may be equivalent to ours, as
Chinese writing is in fact equivalent to our alphabet, although
it is infinitely different, and might appear to have been in
vented by a deaf man. I learn, through the favor of a great
prince, of one born deaf and dumb in Paris, whose ears have
at last attained to the performance of their function, that he
has now learned the French language (for it is from the court
of France that he was summoned not long since), and that he
could say very curious things about the conceptions he had in
his former condition and about the change of his ideas when
he commenced to exercise the sense of hearing. These per
sons born deaf and dumb can go farther than we think.
There was one in Oldenburg in the time of the last Count
who became a good painter, and showed himself very rational
in other respects. A very learned man, a Breton by nation,
told me that at Blainville, about ten leagues from Xantes,
belonging to the Duke of Kohan, there was, about 1690, a
poor man, who lived in a hut near the castle outside of the
town, who was born deaf and dumb, and who carried letters
and other things to the town and found the houses, following
some signs which the persons accustomed to employ him
made him. Finally the poor man became blind also, but did
not give up rendering some service and carrying letters into
the town to whatever place they indicated to him by touch.
He had a board in his hut which, extending from the door to
the place where his feet were, informed him by its motion
when any one entered his house. Men are very negligent in
CH. ix] ON HUMAN UNDERSTANDING 141
not obtaining an exact knowledge of the modes of thought
of such persons. If he no longer lives, there is probably
some one in the vicinity who could still give some information
respecting him, and make us understand how they showed him
the things he was to do. But to return to what the man born
blind, who begins to see, would think of the globe and the
cube, seeing them without touching them, I reply that he will
distinguish them, as I have just said, if any one informs him
that the one or the other of the appearances or perceptions
which he has of them belongs to the cube or to the globe ;
but, without this previous instruction, I admit that he will
not at first venture to think that the kinds of pictures which
they make of themselves in the depths of his eyes, and which
might come from a flat picture upon the table, represent the
bodies, until touch convinces him of the fact, or until, by
force of reasoning upon the rays of light according to optics,
he understands by the lights and shades that there is a some
thing which arrests these rays of light, and that it must be
exactly what remains for him in touch, which result he will
finally reach when he sees this globe and this cube revolve,
and change the shadows and the appearances in accordance
with the motion, or even when, these two bodies remaining at
rest, the light which illumines them changes its place, or his
eyes change their position. For these are about the means
we have of distinguishing from afar a picture or a perspec
tive, which represents a body, from the body itself.
§ 11. Ph. [Let us return to perception in general.] It dis
tinguishes animals from inferior beings.
Tli. [I am inclined to the belief that there is some percep
tion and appetition also in the plants, because of the great
analogy which exists between plants and animals ; and if, as
is commonly supposed, there is a vegetable soul, it of necessity
has perception. Yet I do not cease to attribute to mechanism
all that takes places in the bodies of plants and animals,
except their first formation. Thus I agree that the move
ment of the plant called sensitive arises from mechanism, and
I do not approve of having recourse to the soul when the
question is that of explaining the detail of the phenomena
of plants and animals.]
§ 14. Ph. It is true that for myself, indeed, I cannot help
142 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
believing that even in those kinds of animals which are like
the oysters and mussels there is some feeble perception ; for
quick sensations would serve only to discommode an animal
which is constrained to live always in the place where chance
has put it, where it is watered with water, cold or warm, pure
or salt, according as it comes to it.
Th. [Very well, I also believe that we can say almost as
much of plants ; but in man's case, his perceptions are accom
panied with the power of reflection, which passes to the act
when there is any occasion. But when he is reduced to a state
in which he is as it were in a lethargy and almost without
feeling, reflection and consciousness cease, and universal truths
are not thought of. But the innate and acquired faculties and
dispositions, and even the impressions which are received, in
this state of confusion, do not cease on that account, and are
not effaced, though they are forgotten. They will even have
their turn one day in contributing to some notable result, for
nothing is useless in nature ; all confusion must develop
itself; the animals even, having attained to a condition of
stupidity, ought some day to return to perceptions more ele
vated ; and, since simple substances always endure, we must
not judge of eternity by a few years.]
CHAPTER X
OF RETENTION
§§ 1, 2. Ph. The other faculty of the mind, by which it
advances farther toward the knowledge of things than by sim
ple perception, is that which I call retention, which conserves
the knowledge received by the senses or by reflection. Reten
tion works in two ways : in actually conserving the present
idea, which I call contemplation; and in preserving the power
to bring them again before the mind, and this is what is called
memory.
Th. [One retains also and contemplates innate knowledge,
and very often one cannot distinguish the innate from the
acquired. There is also a perception of images — either those
CH. xi] ON HUMAN UNDERSTANDING 143
which have already existed for some time, or those which are
formed anew in us.]
§ 2. Ph. But you believe with us that these images or ideas
cease to be anything as soon as they are not actually matters
of consciousness ; and that to say that there are ideas reserved
in the memory means at bottom only that the soul has in some
instances the power of reviving the perceptions it has already
had with a feeling which at the same time convinces it that it
has previously had these kinds of perceptions.
Tli. [If ideas were only forms or modes of thoughts, they
would cease with them ; but you yourself have admitted, sir,
that they are internal objects, and in this way can subsist.
And I am astonished that you can always be satisfied with
these naked powers or faculties, which you w^ould apparently
reject in the scholastic philosophers. It would be necessary
to explain a little more distinctly in what this faculty consists
and how it is exercised; and that would make known that
there are dispositions which are the remains of past impres
sions in the soul as well as in the body, but of which we are
conscious only when the memory finds some occasion for them.
And if nothing restored past thoughts, as soon as we no longer
think of them, it would be impossible to explain how the
memory can preserve them ; and to recur for this purpose to
this naked faculty is to speak nowise intelligibly.
CHAPTER XI
OF DISCERNMENT OR THE FACULTY OF DISTINGUISHING IDEAS
§ 1. Ph. Upon the faculty of distinguishing ideas depends
the evidence and certainty of several propositions which pass
for innate truths.
Th. I admit that to think of these innate truths and to
unravel them discernment is necessary ; but they do not on
that account cease to be innate.]
§ 2. Ph. Xow, vivacity of mind consists in recalling
promptly ideas ; but judgment in representing them clearly
and distinguishing them exactly.
144 LEIBNITZ'S CRITIQUE OF LOCKE [UK. n
Th. [Perhaps each is vivacity of imagination, and judg
ment consists in the examination of propositions according to
reason.]
Ph. [I am not averse to this distinction of mind and judg
ment. And sometimes there is judgment in not employing it
too much. For example : to examine certain witty thoughts
by the severe rules of truth and good reasoning is in a certain
sense an insult.
Th. [This remark is a good one; witty thoughts must have
at least some apparent foundation in reason, but it is not
necessary to examine them minutely with too much scrupu
lousness, as it is not necessary to look at a picture from a
position too near it. It is in this, it seems to me, that
Father Bouhours fails more than once in his Art de penser
dans les ouvrages d' esprit1 as when he despises this sally of
Lucan : 2
Victrix causa diis placuit, sed victa Catoni.
§ 4. Ph. Another operation of the mind in respect to its
ideas is the comparison it makes of one idea with another as
regards extension, degrees, time, place, or some other circum
stance ; it is upon this that the great number of ideas com
prised under the term relation depends.
Tli. [According to my view, relation is more general than
comparison, for relations are either of comparison or of concur
rence. The first concern the congruity or incongruity (I take
these terms in a less extended sense) which comprises resem
blance, equality, inequality, etc. The second comprise some
connection, as that of cause and effect, of whole and parts, of
position and order, etc.]
§ 6. Ph. The composition of simple ideas, for the purpose
of making complex ideas, is also an operation of our mind.
We may refer to this the faculty of extending ideas by uniting
those of the same kind, as in forming a dozen from several
units.
Th. [The one is doubtless as much composition as the
1 Dominique Bouhours, 1628-1702, one of the ablest masters of the French
language in the seventeenth century. The title of his work here given follows
Gerhardt's text. The correct title is: Maniere de bien penxer dans les
outrages d' esprit, Paris, 1G87. There were several editions. — TB.
, 128. — TB.
en. xi] ON HUMAN UNDERSTANDING 145
other ; but composition of similar ideas is simpler than that of
different ideas.]
§ 7. Ph. A dog will nurse young foxes, will play with
them, and will have for them the same fondness as for her
own puppies, if they can be made to suck her so long as is
needful for the milk to spread through their entire body.
Moreover it does not appear that animals, who have a large
number of young at once, have any knowledge of their num
ber.
Th. [The love of animals arises from a pleasure which is
increased by habit. But as for the precise number, men even
can know the numbers of things only by some skill, as in using
numerical names in order to count, or figural arrangements
which make them know at once without counting if anything
is wanting.]
§ 10. Ph. Animals do not form abstract thoughts.
Th. [I agree. They apparently recognize whiteness, and
notice it in the chalk or the snow ; but this is not yet abstrac
tion, for that demands a consideration of what is common,
separated from what is particular, and consequently there
enters into it the knowledge of universal truths, which is not
given to the animals. It is well said also that the animals
which speak do not use words to express general ideas, and
that men deprived of the use of speech and of words do not
cease to invent other general signs. I am pleased also to see
that you here and elsewhere so well observe the advantages of
human nature.]
§ 11. Ph. If animals have some ideas, and are not pure ma
chines, as some maintain, we cannot deny that they have reason
in a certain degree, and, for myself, it appears as evident that
they reason as that they feel. But it is only upon particular
ideas that they reason according as their senses represent these
ideas to them.
Th. [Animals pass from one imagination to another by the
connection which they have felt here before ; for example, when
his master takes a stick, the dog fears a whipping. And in
many instances children with the rest of mankind proceed
nowise differently in their passages from thought to thought.
This might be called consecution and reasoning in a very broad
sense. But I prefer to conform to the received usage in conse-
L
146 LEIBNITZ'S CRITIQUE OF LOCKE
crating these terms to man and in limiting them to the knowl
edge of some reason of the connection of perceptions, which
sensations alone cannot give ; their effect being only to cause
us naturally to expect at another time this same connection
-'hich we have noticed before, although perhaps the reasons
are no longer the same, a fact which often deceives those who
are governed only by the senses.]
§ 13. Ph. Idiots lack vivacity, activity, and movement in
the intellectual faculties, whereby they are deprived of the use
of reason. Madmen seem to be at the opposite extreme, for it
does not appear to me that these latter have lost the power to
reason, but having wrongly united certain ideas, they take
them for truths, and deceive themselves in the same way as
those who reason justly upon false principles. Thus you will
see a madman who thinks he is king maintaining by a just
consequence that he should be served, honored, and obeyed
according to his rank.
Th. [Idiots do not exercise reason, and they differ from some
stupid per sons who have good judgment, but, not having prompt
conception, they are despised and disturbed as he would be
who wished to play ombre with persons of distinction and
thought too long and too often of the part he must take. I
remember a learned man who, having lost his memory by the
use of certain drugs, was reduced to this condition, but his
judgment always appeared. A man wholly mad lacks judg
ment on nearly every occasion ; but the vivacity of his imagi
nation may make him agreeable. But there are particular
madmen who make a false supposition at an important point
in their lives, and reason justly thereupon, as you have well
said. There is such a man, well known at a certain court,
who believes himself destined to redress the affairs of the
Protestants and to bring France to reason, for which purpose
God caused the greatest personages to pass through his body
in order to ennoble it ; he desires to marry all the princesses
he sees to be marriageable, but after having made them holy,
in order to have a holy progeny who are to rule the land :
he attributes all the misfortunes of war to the little attention
paid to his advice. In speaking with a certain sovereign,
he takes every necessary measure not to lower his dignity.
When they enter into conversation with him, he maintains
CH. xn] ON HUMAN UNDERSTANDING 147
himself so well that I have doubted more than once whether
his madness is not feigned, for he is not inconvenienced by
it. However, those who know him more intimately assure me
that his madness is wholly genuine.]
CHAPTEE XII
OF COMPLEX IDEAS
Ph. The understanding bears not a little resemblance to
a room wholly dark, which has only certain small openings to
let in from outside exterior and visible images, so that if these
images, coming to be painted in this dark room, could remain
there and be placed in order, so that they could be found upon
occasion, there would be a great resemblance between this
room and the human understanding.
Th. [To make the resemblance greater, you should suppose
that in this room there was a canvas to receive the images, not
even, but diversified by folds, representing the (kinds of) in
nate knowledge ; further, that this canvas or membrane being
stretched would have a kind of elasticity or power of action,
and also an action and reaction accommodated as much to the
past folds as to the newly arrived kinds of impressions. And
this action would consist in certain vibrations or oscillations,
such as are seen in a stretched string so touched that it gives
forth a kind of musical sound. For not only do we receive
images or outlines in the brain ; but we form besides new ones,
when we look at complex ideas. Thus the canvas that repre
sents our brain is necessarily active and elastic. This com
parison would explain tolerably well what passes in the brain;
but as for the soul, which is a simple substance or monad, it
represents without extension these same varieties of extended
masses and perceives them.1]
§ 3. Ph. Now complex ideas are either modes or substances
or relations.
1 According to the principle of Pre-established Harmony. Cf. Systeme
nouveau de la nature, etc., 1(!95, §§ 14, 15; Gerhardt, 4, 484, 485; Erdmann,
127, 128; Jacques, 1, 475, 476; translation, Appendix, p. .— TB.
{48 LEIBNITZ'S CRITIQUE OF LOCKE [UK. n
Th. [This division of the objects of our thought into sub
stances, modes,1 and relations is sufficiently to my taste. I be
lieve that qualities are only modifications of substances, and
that the understanding adds thereto the relations.2 From this
follows more than you think.]
Ph. Modes are either simple (as a dozen, a score, which are
composed of simple ideas of the same kind, i.e. of units) or
mixed (as beauty), into which enter simple ideas of different
kinds.
Th. Perhaps dozen or score are only relations, and are con
stituted only in connection with the understanding. Units are
separate, and the understanding gathers them together how
ever dispersed they be. Yet, although relations are from the
understanding, they are not groundless or unreal. For in the
first place understanding is the origin of things ; and indeed
the reality even of all things, simple substances excepted, ulti
mately consists only of perceptions of the phenomena of sim
ple substances. It is often the same with regard to the mixed
modes ; i.e. it is necessary to refer them rather to the rela
tions.]
§ 6. Ph. The ideas of substances are certain combinations of
simple ideas, which are supposed to represent particular and
distinct things, subsisting by themselves, among which ideas
the obscure notion of substance, which is assumed without
knowing what it is in itself, is always considered as the first
and chief.
Th. [The idea of substance is not so obscure as you think.
You can know what it ought to be, and what it knows of itself
in other things ; and indeed the knowledge of the concrete
always precedes that of the abstract ; the hot (thing) rather
than the heat.]
§ 7. Ph. In regard to substances there are also two kinds of
ideas: the one of single substances, like that of a man, or a
sheep; the other of several substances joined together, as of
an army of men, or a flock of sheep. These collections form
also a single idea.
1 Cf. Descartes, Prin. Philos.. I.. § 50; Veitch's translation, 8th ed., p. 217:
Spinoza, EtJiira, Pt. I., Def. 3; Elwes' translation, Vol. 2. p. 4(5; Locke, Essay,
Bk. II., chap. 12, § 4, Vol. 1, p. 280 (Bonn's ed.).— TR.
'2 Cf. Leibnitz, New Essays, Bk. II., chap. 30, § 4. — TR.
cir. xin] ON HUMAN UNDERSTANDING 149
Tli. [This unity of the idea of aggregates is very true : but
ultimately you must admit that this collective unity is only a
congruity or relation, whose ground is in that which is found
in each of the single substances separately. Thus these beings
by aggregation have no other completed unity than the mental ;
consequently their entity also is in some mental shape or phe
nomenon, as that of the rainbow.]
CHAPTER XIII
OF SIMPLE MODES, AXD FIKST OF THOSE OF SPACE
§ 3. Ph. Space considered with respect to the length which
separates two bodies is called distance; with respect to length,
breadth, and depth it may be called capacity.
Tli. [To speak more distinctly, the distance between two
fixed things (be they points or extensions) is the length of the
shortest possible line that can be drawn from one to the other.
This distance may be considered absolutely or in a certain
figure which comprises the two distant things. For example,
the straight line is absolutely the distance between two points.
But these two points, being in the same spherical surface, the
distance of these two points in this surface is the length of
the shortest great arc of a circle, which may be drawn from
one point to the other. It is well also to notice, that distance
is not only between bodies, but also between surfaces, lines,
points. It may be said that the capacity or rather the interval
between two bodies or two other extensions, or between an
extension and a point, is the space constituted by all the
shortest lines which may be drawn between the points of each.
This interval is filled, except when the two fixed things are
in the same surface, when the shortest lines between the
points of the fixed things must also fall in this surface or
must there be expressly formed.]
§ 4. Ph. Besides that which is in nature, men have estab
lished in their minds the ideas of certain determinate lengths,
as an inch or a foot.
Tli, [They cannot do it. For it is impossible to have the
150 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
idea of a precisely determined length. You can neither say
nor understand by the mind what an inch or a foot is. And
you can preserve the meaning of these terms only by real
measures, which you suppose unchanging, by means of which
you can always recover them. Thus Mr. Greaves,1 an Eng
lish mathematician, desired to make use of the pyramids of
Egypt, which have endured a long time and will endure appar
ently some time longer, to conserve our measures, by showing
posterity the propositions 2 which have been sketched in defi
nite lengths in one of these pyramids. It is true that a little
after it was discovered that pendulums serve to perpetuate
measures (mensuris rerum ad posteros transmittendis) , as Huy-
gens,3 Mouton,4 and Buratini, formerly maistre de monnoye in
Poland, have demonstrated 5 by showing the proportion of our
measures of length to that of the pendulum, which beats pre
cisely a second (for example), i.e. the 86400th6 part of a
revolution of the fixed stars, or of an astronomical day ; and
Buratini has composed a treatise expressly thereupon, which
1 John Greaves, 1602-1052, Savilian Professor of Astronomy at Oxford,
1643-1648. His Pyramidographia, or a Discourse on the Pyramids in Eyypt,
1646. — TR.
2 Gerhardt and Erdmann read: "propositions"; Jacques reads: "propor
tions " ; Schaarschmidt translates " Verluiltnisse." — TR.
3 Christian Huygens, 1629-1695, a Diitch physicist, geometer, and astronomer.
He discovered the laws of double refraction, and was the first to establish on
a sure foundation the wave theory of light, in his Traite de la lumiere,
Leyden, 1690. His researches in physical optics constitute his chief claim to
scientific immortality. His application of the pendulum to regulate the move
ment of clocks, arising from his felt need of an exact measure of time in
astronomical observations, dates from 1(556. He published his Description
de I'horloye a pendule in 1G57, and presented his first "pendulum-clock" to
the States-General June 16, 1657. This Description was republished as chap. 1
of his maaiium opus, the Horoloyium oscillator inm, sive de motu pendulorum
ad horolof/ia adaptato, dedicated to Louis XIV., March 25, 1073. In chap. 4 of
this work he determined the centre of oscillation of a pendulum, and conse
quently the length of the simple isochronous pendulum. His' works were
published in two vols. 4to, Opera varia, Leyden, 1724, and two supplementary
vols. 4to, Opera reliqua, Amsterdam, 1728. — TR.
4 Gabriel Mouton, 1018-1694, a French mathematician and astronomer,
principally known by his Observationes diametrorum solis et lunse apparen-
tium, Lyons, 1670. His principal title to honorable mention in the history
of science is the invention of the method of differences for the calculation of
tables of every kind, afterwards reduced to a system by Sir Isaac Newton,
1042-1727, and known by us as our method of interpolation. — TR.
5 Erdmann and Jacques read : " pre'tendu montrer," i.e. claimed to demon
strate. — TR.
6 Erdmann and Jacques read : " 864,000th," evidently an error. —TR.
CH. xin] ON HUMAN UNDERSTANDING 151
I have seen in manuscript. But there is, however, this imper
fection in this measure of pendulums, which must be limited
to certain countries, for pendulums to beat in the same time
need to be shorter at the equator. And it is furthermore
necessary to assume the constancy of the really fundamental
measure, viz. : the length of a day or of a revolution of the
globe of the earth around its axis, and also of the cause of
gravitation, not to speak of other circumstances.]
§ 5. Ph. Observing how extremities are terminated either
by straight lines which form distinct angles, or by curved lines
in which no angle can be perceived, we form the idea of figure.
Tli. [A superficial figure is terminated by a line or by lines :
but the figure of a body can be limited without determined
lines, as for example that of a sphere. A single straight line
or plane surface cannot enclose any space or make any figure.
But a single line can enclose a superficial figure, for example
the circle, the oval, as also a single curved surface can enclose
a solid figure, like the sphere and the spheroid. Yet, not only
several straight lines or plane surfaces, but also several curved
lines or several curved surfaces, can concur together and form
even angles between themselves, when the one is not the tan
gent of the other. It is not easy to give the definition of figure
in general according to the usage of geometers. To say that it
is a limited extension would be too general, for a straight line,
for example, although terminated by the two ends, is not a
figure and even two straight lines cannot make one. To say
that it is an extension limited by an extension is not general
enough, for the entire spherical surface is a figure and yet it is
not limited by any extension. It may be said, however, that
figure is a limited extension, in which there are an infinite num
ber of paths from one point to another. This definition com
prises limited surfaces without terminating lines which the
preceding definition did not comprise, and excludes the lines,
because from one point to another in a line there is only one
path or a determined number of paths. But it will be still
better to say that figure is limited extension, which may admit
an extended section, or better which has breadth, a term which
hitherto had not been further defined.]
§ G. Ph. At the least all figures are only simple modes of
space.
152 LEIBNITZ'S CRITIQUE OF LOCKE [UK. n
Th. [According to your view, the simple modes repeat the
same idea, but in figures there is not always the repetition of
the same mode. Curves differ much from straight lines and
between themselves. So I do not know how the definition of
the simple mode will be in place here.]
§ 7. Ph. [We need not take our definitions too strictly.
But let us pass from figure to place.'] When we find all the
pieces upon the same squares of the chess-board where we left
them, we say that they are all in the same place, although per
haps the chess-board has been moved. We say also that the
chess-board is in the same place, if it remains in the same part
of the cabin of the vessel, although the vessel has sailed. The
vessel is also said to be in the same place supposing it
keeps the same distance with reference to the parts of the
neighboring countries, although the earth has perhaps turned
round.
Th. [Place is either particular when considered with regard
to certain bodies, or universal when it relates to all, and with
reference to which all the changes possible in relation to any
body are taken into- account. And if there were nothing fixed
in the universe, the place of each thing could still be deter
mined by reasoning,1 if there were means of making a record of
all the changes, or if the memory of a creature could suffice for
them, as they say, the Arabs play chess by memory and on
horseback. What we cannot understand, however, is neverthe
less determined in the truth of things.]
§ 15. Ph. If any man asks me what space is, I am ready to
tell him when he tells me what extension is.
Th. [I wish I could speak of the nature of fever or any other
malady with the same certainty with which I believe the nature
of space is expounded. Extension is the abstract of the ex
tended. Xow the extended is a continuum whose parts are
coexistent, or exist at the same time.]
§ 17. Ph. If any one asks whether space without body is
1 Schaarschmidt says that the statements here made by Leibnitz have since
found their confirmation and accomplishment through Gauss' Theoria motus
corporum coelestium. The work was published at Hamburg, in 180!>, and
"gave a powerful impulse to the true methods of astronomical observation."
The author, Carl Friedrich Gauss, 1777-1855, was an eminent German mathe
matician. His collected works, edited by E. J. Schering, have been published
by the Royal Society of Gottingen, 7 vols., 4to. Gottingen : 18G3-1871. — TR.
en. xin] ON HUMAN UNDERSTANDING 153
substance or accident, I should reply without hesitation that I
know nothing about it.
Th. [I fear you may think me vain in wishing to determine
what you, sir, admit you do not know. But if it is expedient
to judge, (I fear) that you know more about the matter than
you state or think you do. Some have believed that God is
the place of things.1 Lessius and Guericke, if I am not mis
taken, were of this opinion, but then place contains something
more than what we attribute to the space which we deprive of
all activity ; and in this way it is no more a substance than
time, and if it has parts it cannot be God. It is jijrelation, an.
order, not ojily_betiy££ji_£xistences, but also between possibili
ties as they may exist. But its truth and reality, like all
eternal truths, is grounded in God.]
Ph. [I am not far from your view, and you know the pas
sage of St. Paul, who says that we live and move and have
our being in God.2 Thus, according to different ways of con
sidering the matter, it may be said that space is God, and also
that it is only an order or a relation.]
Th. [The better statement then will be that space is an
order, but that God is its source.]
§ 18. Ph. [Yet to know whether space is a substance, it
would be needful to know in what the nature of substance in
general consists. But in this there is a difficulty. If God,
finite spirits, and bodies participate in common in an identical
substantial nature, would it not follow that they differ only as
different modifications of this substance ?]
1 This doctrine appeared very early. Schaarschmidt refers to the collection
of poems of uncertain origin called Orphica, where (Fragt. vi.,p. 457, ed. Her
mann, v. 8 and 9) it is poetically expressed thus : " All that has heen and here
after will be, is formed together in the bosom of Zeus." Again (v. 17-20) :
"One is the ruling Being, in whom the All moves, tire, water, earth and air,
day and night, reason, the first principle and joyful love — all this lies in the
great bosom of Zeus," etc. Malebranche represents a phase of the same view
in his doctrine that we see all things in God. Cf. his De la Recherche de la
Verite, III., ii., 6: " We abide thus in the view that God is the intelligible
world or the place of spirits, just as the material world is the place of bodies.
From His power they receive all their modifications, in His wisdom they find
all their ideas, by His love they are moved in all their moral inclinations. But
because His power and His love are nothing else than Himself, we will believe
with St. Paul, that He is not far from any one of us, and that in Him we live
and move and have our being." Cf. also James Martineau, Ti/pcs of Ethical
Theory, 2d ed., Vol. 1, p. 170 sq. New York : Macmillan & Co., 1886. — TR.
2 Acts 17 :28. — TR.
154 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
Th. [If this result follows, it would follow also, that God,
finite spirits, and bodies, participating in common in an iden
tical nature of being, would differ only as different modifica
tions of this being.]
§ 19. Ph. Those who first thought of regarding accidents as
a kind of real beings, which need something in which to inhere,-
were constrained to invent the word substance to serve as a
support to the accidents.
Th. [Do you then think, sir, that the accidents can subsist
apart from the substance ? or do you mean that they are not
real beings ? You seem to multiply difficulties without reason,
and I have remarked above that substances or concretes are
conceived rather than accidents or abstracts.]
Ph. The words substance and accident are in my view of
little use in philosophy.
Th. [I admit that I am of another opinion, and I believe
that the consideration of substance ] is one of the most important
and fruitful points of philosophy.]
§ 21. Ph. [We have now spoken of substance only by the
way, while asking if space is a substance. But it is sufficient
for us that it is not a body.] No one will dare to make body
infinite like space.
Th. [Descartes and his followers have said, nevertheless,
that matter has no limits, in making the world indefinite, so that
it is not possible for us to conceive of its extremities. And
they have changed the term infinite into indefinite with some
reason ; for there never is an infinite whole in the world,
1 Cf. New Essays, Bk. II. , chap. 23, § 2; De primie philosophise cinendn-
tlone et de notions substantive, 1694, Gerhardt, Vol. 4, pp. 408— 170; Erdmann,
pp. 121-122; A. Jacques, (Euvres de Leibniz, Vol. 1, pp. 452-454 (in French) ;
translation, Appendix, pp. ; Systeme nouveau de la nature et de la
communication des substances, auxxi bien que de V union qu'il y a entre Vi'nne
et le corps, 1695, §§ 2, 3, Gerhardt, Vol. 4, pp. 477 sq. ; Erdmann, pp. 124-128;
Jacques, Vol. 1, pp. 469 sq.; translation, Appendix, pp. ; DC ipxa
natura, sire de vi insita act ionib usque creaturum, 1698, Gerhardt, Vol. 4, pp.
504-510; Erdmann, pp. 154-160; Jacques, Vol. 1, pp. 455-468 (in French) ; trans
lation, Appendix, pp. ; Considerations sitr le principc de rie et sur
les natures plastiques, 1705, Gerhardt, Vol. 6, pp. 539-540 ; Erdmann, pp.
429-432; translation, Duncan, Philos. Works of Leibnitz, pp. 163-109; Prin
cipe s de la nature et de la f/racefondes en raison, c. 1714, Gerhardt, Vol. 0,
pp. 598-606; Erdmann, pp. 714-718 : translation, Duncan, op. cit., pp. 2051-217:
La Monadoloaie, 1714, Gerhardt, Vol.6, pp. 607-623; Erdmann, pp. 705-712;
translation, Duncan, op. cit., pp. 218-232 ; alsoF. H. Hedge, in "The Jour. Spec.
Philos.," Vol. 1, pp. 129-137. — TR.
CH. xiv] ON HUMAN UNDERSTANDING 155
although there are always soine wholes greater than others to
infinity, and the universe even cannot pass for a whole as I
have elsewhere l shown.
Ph. Those who take matter and extension as one and the
same thing maintain that the inner sides of a hollow vacuous
body would touch. But the space which is between two bodies
suffices to prevent their mutual contact.
Tli. [I am of your opinion, for although I do not admit a
vacuum, I distinguish matter from extension, and I admit that
if there were a vacuum in a sphere, the opposite poles in the
hollow space would not on that account touch. But I believe
that this is a case which the divine perfection does not allow.]
§ 23. Ph. It seems, however, that motion proves a vacuum.
When the least part of the divided body is as large as a grain
of mustard-seed, a void space equal to the size of a grain of
mustard is requisite in order to make room for the parts of
this body to move freely ; the same condition will hold good
when the parts of the matter are one hundred million times
smaller.
Th. [It is true, that if the world were full of hard corpus
cles, which could neither yield nor divide, as the atoms are
depicted, motion would be impossible. But in truth, there is no
original hardness ; on the contrary, fluidity is the original
condition, arid, bodies are divided as needful, since there is
nothing. to prevent it. This takes away all the force in the
argument for a vacuum drawn from motion.]
CHAPTEK XIV
OF DURATION AND ITS SIMPLE MODES
§ 10. Ph. To extension corresponds duration. And a part
of duration in which we remark no successions of ideas we
call an instant.
Th. This definition of an instant ought (I believe) to mean
the popular notion, like that which the common people have
1 Cf. ante, pp. 16, 17; also yew JZwnjx, Bk. II., chap. 17, § 1. The proof that
the universe is not, strictly speaking, a whole, is .u'iven in the letter to Des
Bosses, March 11, 170(3, Gerlmrdt, Vol. 1', p. 304 yq., Erdmann, pp. 435-436. — TR.
150 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
of a point. For strictly the point and the instant are not
parts of time or space, neither have they parts. They are
extremities only.
§ 16. Ph. It is not motion, but a constant succession of
ideas which gives us the idea of duration.
T/L [A_succession of perceptions awakes in us the idea of
duration, but it does not make it. Our perceptions never have
a succession sufficiently constant and regular to correspond to
that of time, which is a continuum uniform and simple, like a
straight line. Changing perceptions furnish us the occasion
for thinking of time, and we measure it by uniform changes.
But were there nothing uniform in nature, time could not be
determined, as space likewise could not be determined if there
were no fixed or immovable body. So that knowing the rules
of different motions, we can always refer them to the uniform
intelligible motions, and see beforehand by this means what
will happen through the different motions taken together.
And in this sense time is the measure of motion, i.e. uniform
motion is the measure of non-uniform motion.]
§ 21. Ph. No two parts of duration can certainly be known
to be equal; [and you must admit that observations can attain
only approximate equality.] After exact research the dis
covery has been made that there is really an inequality in the
diurnal revolutions of the sun, and we do not know but that
the annual revolutions are unequal also.
Tli. [The pendulum has made us realize and see the in
equality of the days from one noon to another : Solein dicere
falsiim audet. It is true that men knew this already, and that
this inequality has its rules. As for the annual revolution,
which makes good the inequalities of solar days, it may change
in the course of time. The revolution of the earth about its
axis which is commonly attributed to the primum mobile,1 is our
best measure up to the present time, and clocks and watches
serve to divide it for us. Furthermore this same daily revolu-
1 In Aristotle's philosophy, ™ Trpurov KIVOVV, i.e. God, who, himself unmoved,
is. the necessary first and unceasing source of the eternal movement of the uni
verse. Cf. Metaphys., A, 6-10, 1071 sq.; Phys., VIII.,6, 258& 10; also Zeller,
Outlines, § 56, 3, and Die Philos. d. Griech., 3d ed., 1879, Vol. 4, p. 358;
Wallace, Outlines of the Philos. of Aristotle, 3d ed., § 39; Hegel, Gesch. d.
Philos., 2d ed., Vol. 2, p, 289 sq.; Benn, The Greek Philosophers, Vol. 1, pp.
348-350. — TR.
CH. xiv] ON HUMAN UNDERSTANDING 157
tion of the earth may also change in the course of time : and
if any pyramid could endure long enough, or if we should build
new ones we could perceive it by observing there the length of
pendulums a known number of whose beats occurs now during
this revolution ; we could also know in some way the change
by comparing this revolution with others, as with those of
Jupiter's satellites, for it is not apparent that, if there is any
change in one or the other, it will always be proportional.
Ph. Our measure of time would be more exact if we could
preserve a past day in order to compare it with the days to
come, as we preserve the measures of space.
Th. [But instead of that we are reduced to preserving and
watching bodies which move in nearly equal times. Also we
cannot say that a measure of space, as for example, an ell
which is preserved in wood or metal remains perfectly the
same.]
§ 22. Ph. INOW since all men manifestly measure time by
the motion of the heavenly bodies, it is very strange that one
is not permitted to define time as the measure of motion.
Th. [I just stated (§ 16) how that should be understood. It
i-s true that Aristotle says1 that time is the number and not the
measure of motion. And in fact, it may be said that duration
is known by the number of periodic equal motions of which
one begins when another ends, for example, by so many revolu
tions of the earth or the stars.]
§ 24. Ph. Xevertheless to anticipate these revolutions and
say that Abraham was born in the year 2712 of the Julian era,
is to speak as unintelligibly, as if you counted from the begin
ning of the world, although you suppose that the Julian era
commenced several hundred years before there were any days,
nights, or years marked by any revolution of the sun.
Th. [This vacuum which may be conceived in time, indicates,
like that of space, that time and space extend to the possible as
well as to the actual. Besides, of all the chronological methods,
that of reckoning the years since the beginning of the world is
the least convenient, although this would be, without touching
upon other reasons, only because of the great difference exist
ing between the Septuagint and the Hebrew text.]
1 Phys., IV., 11, 219M, 219b8; cf. Wallace, Outlines of the Philos. of Aris
totle, 3d ed., § 44. Wallace quotes the Greek of the first passage here referred
to. — TB.
158 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
§ 26. Ph. One may conceive the beginning of motion, al
though he may not comprehend that of duration taken in all
its extension. One may give limits to the body, but cannot do
it with regard to space.
Tli. [It is as I just said that time and space indicate the
possibilities beyond the supposition of existences. Time and
space are of the nature of eternal truths which consider equally
the possible and the actual.]
§ 27. Ph. In fact the ideas of time and eternity come from
the same source, for we can in our thought add certain lengths
of duration to one another as often as we please.
Th. [But in order to draw from them the notion of eternity.
it is necessary to think besides that the same reason always
exists for going farther. It is this rational consideration which
achieves the notion of the infinite or the indefinite in possible
progress. Thus the senses alone cannot suffice to cause the
formation of these notions. And ultimately it may be said
that the idea of the absolute1 is anterior in the nature of things
to that of the limits which are added, but we notice the former
only as we commence with what is limited and strikes our
senses.]
CHAPTER XV
OF DURATION AXD EXPANSION CONSIDERED TOGETHER
§ 4. Ph. One admits more easily an infinite duration of
time than an infinite expansion of space, because we conceive
infinite duration in God, and attribute extension only to matter
which is finite, and call the space beyond the universe imaginary.
But (§2) Solomon seems to have other thoughts when, speak
ing of God, he says : the heaven and the heaven of heavens can
not contain Thee;'2 and for myself I believe that he magnifies
too highly the capacity of his own understanding who imag
ines he can extend his thoughts farther than the place where
God exists.
1 The idea of the absolute belongs to our reason as such, cf. New Essays,
Bk. II., chap. 17, § 3, Th., § 16, Th., though we first become aware of it through
our consciousness of the particular ideas of the reason as limitations of the
idea of the absolute. — Tit.
2 1 Kings 8 : 27; 2 Chron. 6 : 18. — TR.
OX HUMAX UNDERSTANDING
Tli. If God were extended, he would have parts. But dura
tion grants these only to his works. However in relation to
space immensity must be attributed to him, which gives also
parts and order to the immediate works of God. He is the
source of possibilities as of actualities, of the one by his
essence, of the other by his will. Thus space like time has
its reality only from him, and he can fill the void when it
seems to him good. Thus it is that in this respect he is
everywhere.1]
§ 11. Ph. We do not know what relations spirits have with
space, nor how they participate therein. But we know that
they participate in duration.
Tli. [All finite spirits are always united to some organic
body, and they represent to themselves other bodies by means
of relations to their own. Thus their relation to space is as
evident as that of bodies. For the rest, before leaving this
subject, I would add a comparison between time and space to
those which you have given; viz. : — if there were a vacuum
in space (as, for instance, if a sphere were hollow within), you
could determine its size; but if there were a vacuum in time,
i.e. a duration without changes, it would be impossible to
determine its length. Whence it comes that you may refute
the one who would maintain that two bodies, between which
there is a vacuum, touch ; for geometry defends the proposition
that two opposite poles of a hollow sphere would not touch :
but you cannot refute the one who would maintain that two
worlds, the one of which succeeds the other, touch as to dura
tion, so that the one necessarily begins when the other ends,
without the possibility of an interval. You could not refute
it, I say, because this interval is indeterminable. If space
were only a line, and if body were immovable, it would no
longer be possible to determine the length of the vacuum
between two bodies.
1 God, according to Leibnitz, is actvs purus, a pure spirit, without body and
without extension. All other beings require bodies. His omnipresence is
dynamic. Cf. New Essays, Bk. II., chap. 1, § VI. Th.. ante, p. 113; Letter to
Des Bosses, Oct. 16, 170G, Gerhardt, Vol. 2, p. 325, Erdmann, p. 440, b. — TR.
100 LEIBNITZ'S CRITIQUE OF LOCKE [BK= 3:.
CHAPTER XVI
OF NUMBER
§ 4. Ph. In numbers ideas are both more precise and more
accurately to be distinguished the one from the other than in
extension, where you cannot observe or measure each equality
and each excess of size as easily as in. numbers., because in
space we cannot by thought attain a certain definite smallness
beyond which we cannot go, like the unit in number.
Tk. [That should be understood of the integer. For other
wise number ni its extent, comprising the fraction, the surd, the
transcendent, and all that may be assumed between two inte
gers, is proportional to the line, and there is there as little of
a minimum as in the continuum. Thus the definition of num
ber as a multitude of units is in place only among the integers.
The precise distinction of ideas in extension does not consist
in size : for to distinguish size clearly one must have recourse
to integers, or to other (measures) known by means of inte
gers ; thus from continuous quantity it is necessary to recur to
discrete quantity, in order to have a distinct knowledge of size.
Thus the modifications of extension, when not joined to num
bers, cannot be distinguished by figure, taking this term so
generally that it means everything which makes two exten
sions dissimilar the one to the other.]
§ 5. Ph. By repeating the idea of a unit and joining it to
another unit, we make a collective idea, which we call two.
And whoever can do that and advance always by adding one
more to the last collective idea to which he gives a particular
name, can count so long as he has a set of names and sufficient
memory to retain them.
Tli. [By this means alone one cannot advance very far.
For memory would be too heavily loaded if it must retain an
entirely new name for each addition of a new unit. That is
why a certain order and a certain repetition of these names is
necessary by recommencing in accordance with a certain pro
gression.]
Ph. The different modes of numbers are capable of no other
CH. XVH] ON HUMAN UNDERSTANDING 161
difference than that of more or less ; [this is why there are
simple modes like those of extension.]
Th. [That may be said of time and of the straight line, but
not of figures, and still less of numbers, which are not only
different in size but further unlike. An even number may be
divided into two equal numbers, but not an uneven. Three
and six are triangular numbers, four and nine are squares,
eight is a cube, etc. And this principle has plaqe in numbers
still more than in figures, for two unequal figures may be per
fectly similar to each other, but never two numbers. But I
am not astonished that you are often deceived thereupon, be
cause one does hot commonly have a distinct idea of what is
similar or dissimilar. You see then, sir, that your idea or
your application of simple or mixed modes is greatly in need of
correction.]
§ 6. Ph. [You were right in remarking that it is well to
give numbers their own names to be retained.] Thus I believe
that it would be convenient in computation to say a billion for
brevity's sake instead of a million of millions, and instead of a
million of millions of millions, or a million of billions, to say
a trillion, and thus in order to nonillions, for there is little
need of going farther in the use of numbers.
Th. These denominations are good enough. Let a* = 10.
That posited, a million will be it-8, a billion a;12, a trillion a;18,
etc., and a nonillion ar54..
CHAPTER. XVII
OF INFINITY
§ 1. Ph. One of the most important notions is that of
the finite and the infinite, which are regarded as modes of
quantity.
Th. [Properly speaking, it is true that there is an infinite
number of things, i.e. that there are always more of them than
can be assigned. 3>ut there is no infinite number, neither line
nor other infinite quantity, if these are understood as veritable
wholes, as it is easy to prove. The schools have meant or have
been obliged to say that, in admitting a syncategorematic in-
M
102 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
finite,1 as they call it, and not a categorematic infinite. The
true infinite exists, strictly speaking, only in the absolute, which
is anterior to all composition, and is not formed by the
additions of parts.2]
P/i. When we apply our idea of the infinite to the first
Being, we do it primarily in respect to his duration and ubi
quity, and, more figuratively, to his power, his wisdom, his
goodness, and his other attributes.
Tli. [Xot more figuratively, but less immediately, because
the other attributes make their importance known through
relation to those into which enters the consideration of
parts.]
§ 2. Pli. I thought it was established that the mind regards
the finite and the infinite as modifications of extension 3 and
duration.
Tli. [I do not find that it has been established that the con
sideration of the finite and the infinite takes place wherever
there is bulk and magnitude. And the true infinite is not a
modification, it is the absolute ; on the contrary, when it is
modified, it is limited and forms a finite.]
§ 3. Ph. We have believed that since the power of the
mind to expand without limit its idea of space by new addi
tions is always the same, it is thence that the idea of an infi
nite space is derived.
Tli. [It is well to add that this is because the same ratio is
seen always to hold good. Let us take a straight line and
prolong it until it is double the length of the first. Now it
is clear that the second line, being perfectly similar to the
first, may be itself doubled in order to have a third, which is
still similar to the preceding ; and the same ratio holding
good always, it is never possible to stop the process ; thus
the line may be prolonged to infinity, so that the consideration
of the infinite arises from that of similarity or from the same
ratio, and its origin is the same with that of universal and
necessary truths. This shows us how what gives completion
1 An incompletely defined infinite, capable of or needing still further defini
tion, but infinite only so far as it cannot really be defined, the indefinite-
injinite (infinitiim-indefinitum) . — TR.
2 Cf. ante, pp. 16, 17 ; also New Essays, Bk. II., chap. 13, § 21. — TR.
3 Locke has: "expansion," Philos. Works, Vol. 1, p. 331 (Bonn's ed.).—
TR.
CH. xvn] ON HUMAN UNDERSTANDING 163
to the conception of this idea is found in ourselves, and can
not come from the experience of our senses, just as necessary
truths cannot be proved by induction nor by the senses. The
idea of the absolute is in us internally, like that of being ; these
absolutes are nothing else than the attributes of God, and it
may be said that they are not less the source of ideas, because
God is himself the principle of beings. The idea of the abso
lute in relation to space, is only that of the immensity of
God, and so of the others. But you deceive yourself in wish
ing to imagine an absolute space which is an infinite whole
composed of parts ; there is none such, it is a notion which
implies a contradiction, and these infinite wholes, and their
opposed infinitesimals, are used only in the calculations of
geometers, just like the imaginary roots of algebra.]
§ 6. Ph. [We conceive furthermore a magnitude without
understanding thereby parts outside of parts.] If to the most
perfect idea I have of the whitest w7hiteness, I add another of
an equal or less brilliant whiteness (for I cannot add the idea
of a whiter than I have, which I suppose the whitest that I
actually conceive), it neither increases nor extends my idea in
any way ; therefore the different ideas of whiteness are called
degrees.']
Th. [I do not fully understand the force of this reasoning,
for nothing prevents me from receiving the perception of a
whiter whiteness than what is actually conceived. The true
reason why we are inclined to believe that wrhiteness cannot be
infinitely increased is because it is not an original quality ;
the senses give us only a confused knowledge of it ; and when
we have a distinct knowledge of it, we shall see that it arises
from the structure, and is limited by that of the organ of
vision. But as regards original or distinctly knowable quali
ties, we see that there are sometimes means of going to
infinity, not only in the case of extension or, if you prefer,
diffusion or what the scholastic philosophy calls paries extra
paries, as in time and place, but also in the case of intention or
degrees, for example, as regards velocity.]
§ 8. Ph. We have no idea of infinite space, and nothing is
plainer than the absurdity of an actual idea of an infinite
number.
Th. [I am of the same opinion. But this is not because we
164 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
cannot have the idea of the infinite, but because the infinite
cannot be a true whole.]
§ 16. Ph. For the same reason we have then no positive
idea of an infinite duration or of eternity, any more than of
immensity.
Th. [I believe we have a positive idea of both, and this
idea is a true one, provided it is not conceived as an infinite
whole, but as an absolute or attribute without limits which
exists in reference to eternity, in the necessity of the existence
of God, without depending upon parts and without the notions
being formed by an addition of time. We see furthermore in
that way, as I have said already, that the origin of the notion
of the infinite comes from the same source as that of necessary
truths.]
CHAPTER XVIII
OF OTHER SIMPLE MODES
Ph. There are besides many simple modes formed from
simple ideas. Such are (§ 2) modes of motion, as sliding,
rolling; those of sound (§ 3) which are modified by notes and
airs, as colors by degrees, not to speak of tastes and smells
(§0). These always1 have neither measures nor distinct
names any more than in the case of the complex modes (§ 7),
because use regulates them, and we will speak of them more
fully when we come to words.
Th. [The majority of modes are not sufficiently simple and
can be reckoned with the complex, for example, to explain what
sliding and rolling is besides motion, you must consider sur
face-resistance-.]
CHAPTER XIX
OF THE MODES OF THINKING
§ 1. Ph. [Let us pass from the modes which come from the
senses to those given us by reflection.] Sensation is, so to
speak, the actual entrance of ideas into the understanding by
1 Locke: "ordinarily," Philos. Works, Vol. 1, p. 34(5 (Bolm's ed.).— Tit.
CH. xix] ON HUMAN UNDERSTANDING 165
means of the senses. When the same idea comes again into
the mind, without the action upon our senses, of the external
object which at first caused it to spring up, the act of the
mind is called remembrance ; if the mind tries to recall it, and
only after considerable effort finds and brings it to view, it is
recollection (recueillement).1 If the mind looks upon it atten
tively for a long time it is contemplation; when the idea floats
about in the mind without any attention on the part of the
understanding, it is called reverie. When the mind reflects
upon ideas, which present themselves, and when it, so to speak,
registers them in its memory, it is attention ; and when the
mind fixes itself upon an idea Avith much application, considers
it on all sides, and will not be turned aside notwithstanding
other ideas which come in the way, we call it study or intense-
ness of thought. Slee$) accompanied by no dream is a cessa
tion of all these things ; and dreaming is having these ideas in
the mind while the outer senses are closed, so that they do
not receive the impressions of external objects with their
usual quickness. It is, I say, having ideas without any sug
gestion from any external objects or known occasion, and
apart from any choice or determination in any way of the
understanding. As for that which we call ecstasy, I leave
others to judge whether it is not dreaming with the eyes open.
Tli. [It is well to clear up these notions and I will try to
aid in the work. I will say then that it is sensation when an
external object is perceived; that remembrance consists in the
repetition without the reappearance of the object ; but when
we know we have had it, it is memory. Recollection (recneille-
ment) is commonly understood in a sense different from yours,
viz. : as a state in which we disengage ourselves from things
in order to apply ourselves to some meditation. But since
there is no word known to me corresponding to your notion,
sir, one may apply to it that which you employ. We give
attention to objects which we distinguish and prefer to others.
Attention continuing in the mind, whether the external object
continues or not, and even whether it is found there or not, is
1 Cf. below, where the French " recueillement," here employed as ;i trans
lation of the English "recollection," is shown to have a different meaning
and use from that of the English word. As " recueillement " is, however, used
as an equivalent for the English word, I have translated it in the second para
graph accordingly. — Tit.
1G6 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
consideration; which tending to knowledge without reference
to action, will be contemplation. • Attention, whose aim is to
learn (i.e. the attainment of knowledge for the sake of keep
ing it), is study. To consider in order to form a plan is to
meditate ; but reverie appears to be nothing else than following
certain thoughts for the pleasure one takes therein, with no
other end ; this is why reverie may lead to madness ; we forget
ourselves, we forget the die cur hie, wre approach dreams and
chimeras, we build castles in Spain. We can distinguish
dreams from sensations only because they are not united with
them, they are like a world apart. Sleep is a cessation of sen
sations, and in this way ecstasy is a very deep sleep from which
one finds difficulty in being awakened, a condition which arises
from some internal passing cause, which is added in order to
exclude this profound sleep, arising from some narcotic or
from some continuous injury to the functions, as in lethargy.
Ecstasy is sometimes accompanied with visions; but there is
vision without ecstasy, and vision seems to be nothing but a
dream which passes for a sensation just as if it acquainted us
with the truth of objects. And when visions are divine, there is
actually truth in them, which may be known for instance when
they contain particular prophecies which the outcome justifies.]
§ 4. Ph. From the different degrees of intensity l or relaxa
tion of the mind, it follows that thought is the act and not the
essence of the soul.
Th. [Doubtless thought is an act and cannot be the essence :
but it is an essential act, and all substances are of this charac
ter. I have shown above that we always have an infinite
number of little perceptions, without being conscious of them.
We are never without perceptions, but we are necessarily often
without apperceptions, viz. : when there are no distinct per
ceptions. It is from not having considered this important
point that a relaxed philosophy, as little noble as solid, has
prevailed with so many excellent minds, and that we have
hitherto almost ignored that which is most beautiful in the
soul. This is also the reason why so much probability has
been found in that error, which teaches that souls are by
nature perishable.]
1 Locke has: "intention and remission," Philos. Works (Bonn's ed.), Vol.
1, p. 349. — TR.
CH. xx] ON HUMAN UNDERSTANDING 167
CHAPTER XX
OF MODES OF PLEASURE AXD PAIN
§ 1. Ph. As the sensations of the body,. like the thoughts
of the mind, are either indifferent or followed by pleasure or
pain, the ideas of them cannot be described any more than all
other simple ideas, nor can the words which serve to designate
them be denned.
Th. [I believe that there are no perceptions which are
wholly indifferent to us, but it is enough that their effect be
not notable in order that they may be thus spoken of, for
pleasure and pain appear to consist in a notable aid or impedi
ment. I admit that this definition is not at all nominal and
that one may give none at all.]
§ 2. Ph. The good is that which is fitted to produce and
increase pleasure in us, or to diminish and cut short some
pain. Evil is fitted to produce or increase pain in us, or to
diminish some pleasure.
Th. [I am also of this opinion. The good is divided into
the virtuous, the agreeable, and the useful, but ultimately I
believe that it must be either agreeable itself, or serving some
thing else which may give us an agreeable feeling, that is to
say, the good is agreeable or useful, and virtue itself consists
in a pleasure of mind.]
§§ 4, 5. Ph. From pleasure and pain come the passions.
We have love for that which can produce pleasure, and the
thought of sadness or of pain that a present or absent cause
can produce is hatred. But hatred or love which relates to
beings capable of happiness or misery is often an uneasiness or
delight which we feel to be produced in us by the considera
tion of their existence or of the happiness which they enjoy.
Th. [I also gave nearly this definition of love when I
explained the principles of justice, in the preface to my
" Codex juris gentium diplomat icue," l viz. : that to love is to
1 The Codex juris yentium diplomatics, 1693, a collection of public acts
and treatises, etc. An excerpt from the Preface of this work, entitled De no-
tionibus juris et jttstitise, is given by Erdmann, pp. 11H-120; translation, Dun
can, Philos. Works of Leibnitz, note 48, pp. 379-382. — TR.
168 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
be inclined to take pleasure in the complete perfection or hap
piness of the object loved. And for that reason one neither
considers nor asks for any other pleasure proper than that
indeed which is found in the good or pleasure of the one who
is loved ; but in this sense we do not, properly speaking, love
what is incapable of pleasure or happiness, and we enjoy things
of this nature without loving them for that reason, unless by
a prosopopoeia, and as if we imagined that they themselves
enjoy their perfection. It is not, then, properly love when
one says that he loves a beautiful picture for the pleasure
which he takes in feeling its perfections. But it is allowable
to extend the sense of terms, and their usage varies. Philoso
phers and theologians even distinguish two kinds of love, viz. :
the love which they call the love of complacency, which is
nothing but the desire or feeling which we have for the one
who gives us pleasure, without concerning ourselves whether
he receives it; and the love of benevolence, which is the feeling
that one has for the one who, by his pleasure or happiness,
gives us some. The first makes us have in view our pleasure
and the second that of another, but as making or rather consti
tuting ours, for if it did not reflect upon us in some way we
could not concern ourselves with it s^nce it, is impossible,
although they affirm it, to be separated from the good proper.
And see how it is needful to understand disinterested or non-
mercenary love, in order to reach a favorable conception of
nobility and not to fall meanwhile into the chimerical one.]
§ 6. Ph. The uneasiness (French inquietude) which a man
feels in himself at the absence of anything which if present
would give him pleasure is called desire. Uneasiness is the prin
cipal, not to say the only stimulus which excites human industry
and action for whatever good is proposed to man ; if the absence
of this good is followed by no displeasure or pain, and he who is
deprived of it can be content and at his ease without its pos
session, he does not think of desiring, and less still of making
any efforts to enjoy it. He feels for this kind of good only a
bare velleity,1 the term used to signify the lowest kind of desire,
1 Schaarschmidt translates the French " velleite " by the German " Willens-
neig-unjj," i.e. inclination of will. The term is borrowed from the Scholastic
"velleitas," and is here equivalent to int perfect rolition (imperfe<>ta rolitio)
or that condition of the soul in which the will, though not in a state of indii't'er-
CH. xx] ON HUMAN UNDERSTANDING 169
which approaches nearest to that state in which the soul finds
itself with regard to anything which is wholly indifferent to
it, when the displeasure which the absence of anything causes
is so inconsiderable that it is carried only to feeble longings
without being compelled to avail itself of the means of obtain
ing it. Desire is moreover extinguished or abated by the
opinion that the wished for good cannot be obtained in propor
tion as the soul's uneasiness is cured or allayed by that con
sideration. [For the rest, I have found what I stated to you
about uneasiness in this celebrated English author, whose
views I often relate to you. I was a little in difficulty as to
the definition of the English word uneasiness. But the French
translator l whose skill in the fulfilment of this task cannot
be called in question, remarks at the foot of the page (chap.
20, § C,) that by this word the English author understands
the state of a man not at his ease, the lack of ease and of tran
quillity of soul, which in this regard is purely passive, and that
it must be translated by the (French) word inquietude, which
does not express exactly the same idea, but approaches it very
nearly. This caution (he adds) is above all needful with
regard to the following chapter, " Of Power," in which the
author reasons much upon this kind of uneasiness ; for if you
should not attach to this word the idea which has just been
indicated, it would be impossible exactly to understand the
matters treated of in this chapter and which are the most
important and delicate in the entire work.]
Tk. [The translator is right and the reading of his excellent
author shows me that this consideration of uneasiness is a capi
tal point, in which this author has particularly shown his pene
trating and profound mind. For this reason I gave it some
attention, and after having well considered the matter, it al
most appears to me that the (French) word inquietude (restless
ness), if it does not express quite the meaning of the author,
nevertheless sufficiently agrees with the nature of the thing ;
and that the (English) word uneasiness, if it indicated a dis
pleasure, fretf ulness (chagrin), inconvenience, in a word some
effective pain, would not suit his meaning. For I should pre-
ence, has not as yet sufficient force to pass over into action (volitio). Cf. New
Esmi/s, Bk. II., chap. 21, § 5 sq., also § 30, Th. — TR.
i M. Pierre Coste. — TR.
170 LEIBNITZ'S CRITIQUE OF LOC&E [BK. n
fer to say that in the desire in itself there is rather a disposi
tion and preparation for pain than pain itself. It is true that
this perception sometimes differs from that which is in pain
only more or less, but it is the degree which is the essence of
pain, for it is a notable perception. The same is also seen in
the difference between appetite and hunger, for when the
stomach's irritation becomes too strong it is uncomfortable, so
that we must also apply here our doctrine of perceptions too
small to be perceived, for if that which goes on in us when we
have appetite and desire, were great enough, it would cause us
pain. Hence the infinitely wise author of our being arranged
it for our good, when he so arranged it that we should often
be in ignorance and among confused perceptions, in order to
act more promptly by instinct, and in order not to be disturbed
by too distinct sensations of a multitude of objects, which do
not recur immediately and the nature of which could not go on
to obtain their ends. How many insects we swallow without
noticing them, how many persons we see who, having a too
penetrating odor, are annoying, and how many disgusting ob
jects we should see if our vision were penetrating enough. It
is also for the sake of this skill that nature has given us the
stimuli of desire, like the rudiments or elements of pain, or so
to speak, of semi-pains, or (if you wish to speak extravagantly
in order to express yourself more forcibly) the little impercep
tible pains, in order that we might enjoy the advantage of evil
without its inconvenience ; for otherwise if this perception
were too distinct, we would always be miserable while await
ing the good, while this continual victory over these semi-
pains which are felt in pursuing our desire and satisfying in
some way this appetite, or this longing, gives us a quantity of
semi-pleasures, whose continuity and mass (as in the continuity
of the impulse of a heavy body which falls and acquires im
petuosity) becomes at last a complete and genuine pleasure.
And finally, without these semi-pains there would be no pleas
ure at all, nor any means of perceiving that something aids
and relieves us while there are some obstacles which prevent
us from putting ourselves at ease. It is furthermore in this
that we recognize the affinity of pleasure and pain which Soc
rates in Plato's " Phsedo," l noticed when his feet itched. This
1 Phxdo, GOB. — Tn.
CH. xx] ON HUMAN UNDERSTANDING 171
consideration of little aids or little releases and imperceptible
deliverances from the fixed tendency, whose result at last is a
notable pleasure, serves also to give a more distinct knowl
edge of the confused idea which we have, and ought to have, oj
pleasure and of pain ; just as the sensation of heat and of light
results from a quantity of little motions which express those
of objects, as I said above (chap. 9, § 13) and differ from them
only in appearance and because we ourselves are not conscious
of this analysis : while many to-day believe that our ideas of
sense-qualities differ toto genere from notions and from all that
goes on in objects, and are something primitive and inexpli
cable, and indeed arbitrary, as if God made the soul sensible of
whatever seems good to him, instead of what goes on in the
body, a view which is far removed from the true analysis of our
ideas. But to return to uneasiness, that is to say to the little
imperceptible solicitations which keep us always in suspense ;
these are confused determinations, so that often \ve do not
know what we lack, while in the case of the inclinations and
passions we at least know what we ask for, although confused
perceptions enter also into their methods of acting, and the
passions themselves also cause this uneasiness or longing.
These impulses are like so many little springs which try to
release themselves, and which make our machine go. And I
have already remarked above that it is in this way that we are
never indifferent, when we most appear to be so, for example,
in turning to the right rather than to the left at the end of a
path. For the side we take arises from these insensible deter
minations, mixed with the actions of objects and the interior of
the body, which makes us find ourselves more at ease in the one
or the other manner of bestirring ourselves. The pendulum of
a clock is called Unruhe in German, i.e. uneasiness. TVe may
say that the same condition exists in our body -which can
never be perfectly at ease ; because if it might be so. a new
impression of objects, a slight change in the organs, in the ves
sels and in the viscera would at once alter the balance and
cause them to make some slight effort to put themselves again
in the best state possible : this produces a perpetual strife,
which causes, so to speak, the uneasiness of our clock, so that
this appellation is quite to my taste.]
§ 6. Ph. Joy is a pleasure felt by the soul when it consid-
172 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
ers the possession of a present or future good as assured, and
we are in 2~>ossession of a good when it is so in our power that
we can enjoy it when we wish.
Th. [Languages lack words sufficiently suitable to distin
guish kindred notions. Perhaps the Latin gaudium draws
nearer this definition of joy than IcKtitia, which is also trans
lated by the word joy; but then it appears to me to signify a
state in which pleasure predominates in us, for during the pro-
foundest sorrow and in the midst of the most poignant grief
one may take some pleasure as in drinking or hearing music,
but the unpleasant feeling predominates and so in the midst
of the most acute pain the mind can be joyful, as in the case
of the martyrs.]
§ 8. Ph. Sorrow is an uneasiness of the soul when it
thinks of a lost good which it might have enjoyed a longer
time, or when it is tormented by an actually present evil.
Th. [Not only the actual presence, but also the fear of
coming evil may make one sad, so that I believe the definitions
of joy and sorrow which I have just given agree the better
with usage. As to uneasiness, there is in pain and consequently
in sorrow something more : and there is uneasiness even in
joy, for it makes a man awake, active, full of hope to go farther.
Joy has been capable of causing death by excess of emotion,
and then there was in it still more than uneasiness.]
§ 9. Ph. Hope is the contentment of the soul which thinks of
the enjoyment which it is destined probably to have in a thing
suited to give it pleasure. § 10. And fear is an uneasiness
of the soul, at the thought of a future evil that may happen.
Th. [If uneasiness signifies trouble I admit that it always
accompanies fear ; but taking it as this insensible spur which
pushes us on, it may be applied also to hope. The Stoics
regarded the passions as thoughts ; thus hope was to them the
thought of a future good, and fear the thought of a future
evil. But I prefer to say that the passions are neither satis
factions nor displeasures, nor thoughts, but tendencies or
rather modifications of the tendency, which come from thought
or feeling and which are accompanied by pleasure or displeas
ure.]
§ 11. Ph. Des2mir is the thought one has that a good
cannot be obtained, causing sometimes pain and sometimes
rest.
en. xx] ON HUMAN UNDERSTANDING 173
Th. [Despair taken as passion is a kind of strong tendency
which finds itself suddenly arrested, a condition which causes
a violent struggle and much displeasure. But when despair
is accompanied with rest and indolence it is rather a thought
than a passion.]
§ 12. Ph. Anger is the uneasiness or discomposure we feel
after having received some injury, and which is accompanied
with a present desire to avenge ourselves.
Th. [Anger seems to be something simpler and more gen
eral, since animals are susceptible to it to whom no injury is
done. There is in anger a violent effort tending to annul the
evil. The desire for vengeance may remain when one is in
cold blood and has hatred rather than anger.]
§ 13. Ph. Envy is the uneasiness (displeasure) of the soul
which arises from the consideration of a good we desire, but
which another possesses, who in our opinion should not have
had it in preference to ourselves.
Th. [According to this notion envy would be always a
praiseworthy passion and always based upon justice, at least
in our opinion. But I know not whether men do not often bear
envy towards recognized merit, which they would not hesitate
to treat ill, if they had the power. They even bear envy
towards persons regarding a good which they themselves
would not care to have. They would be content to see them
deprived of it, without thinking of profiting from their despoil
ments, and indeed without being able to hope for it. For
some good things are like pictures painted in fresco, which can
be destroyed, but which cannot be taken away.]
§ 17. Ph. Most of the passions make in many persons
impressions on the body, and cause therein various changes,
but these changes are not always sensible ; for example, shame
which is a felt uneasiness of the soul when it comes to consider
that it has done something indecent or which may lessen the esti
mate others have of us, is not always accompanied by blushing.
Th. [If men would study to observe more closely the ex
ternal movements which accompany the passions, it would be
difficult to conceal them. As for shame, it is worthy of consid
eration that modest persons sometimes feel movements similar
to those of shame, when they are witnesses only of an indecent
action.]
174 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
CHAPTEE XXI
OF POWER AXD FREEDOM
§ 1. Ph. [The mind observing how one thing ceases to be,
and how another which was not before comes to exist, and
concluding that there will be in the future parallel cases, pro
duced by parallel agents, comes to consider in one thing the
possibility that one of its simple ideas may be changed, and in
another the possibility of producing that change, and in that
way the mind forms the idea of power.]
Th. [If power corresponds to the Latin potentia, it is opposed
to act, and the passage from power to act is change. This is
what Aristotle understands by the word motion, when he says l
that it is the act or perhaps the actuation of that which is in
power. It may be said then that power in general is the possi
bility of change. Now change or the act of this possibility,
being action in one subject and passion in another, there
will be two powers, one passive, the other active. The active
may be called faculty, and perhaps the passive might be called
capacity or receptivity. It is true the active power is sometimes
taken in a more complete sense, when besides the simple faculty
there is a tendency ; and it is thus that I take it in my dynamical
considerations.2 The word force might be appropriated to it
in particular ; and force would be either entelechy or effort ;
for entelechy (although Aristotle takes it so generally that it
comprises also all action and all effort) appears to me more
appropriate to primitive acting forces, and that of effort to the
derivative. There is even also a kind of passive power more
particular and more endowed with reality ; namely, that which
is in matter in which there is not only mobility, which is the
1 Cf. Fhi/s. III., 1, 201«10; Metaphys. K, 9, 1065'' 16. — TR.
2 Cf. DC primse philosophise emendatione, etc., published in the " Acta
Eruditorum," 1694, p. 110 xq., Gerhardt, Vol. 4, pp. 4(58-470; Erdmann, pp.
121-122; Jacques, Vol. 1, pp. 452-154, in French; translation, Duncan, PhiLoK.
Works of Leibnitz, pp. 68-70; also, Beilac/e,, May, 1702, appended by Gerhardt
to the letter to Fabri, Gerhardt, Leibnizcns Math, tichriften, Vol. (5, pp. 98 sq.,
especially p. 101 ; Specimen difmtniicum, published in the " Acta Erudi
torum." April, 1695, Gerhardt, Leibnizens Math, tichriflen, Vol.6, pp. 234 sq
— Tu.
CH. xxi] ON HUMAN UNDERSTANDING 175
capacity or receptivity for motion, but also resistance, which
includes impenetrability and inertia. Entelechies, i.e. primitive
or substantial tendencies, when accompanied by perception, are
souls.]
§ 3. Ph. The idea of power expresses some kind of relation.
But what one of our ideas of whatever kind does not include some
relation? Our ideas of extension, of duration, of number, do
they not all contain in themselves a secret relation of parts ?
The same thing is noticed in a still more visible manner in
figure and motion. Sensible qualities, what are they but the
powers of different bodies in relation to our perception, and
do they not depend in themselves upon bulk, figure, the con
texture and motion of the parts ? which puts a kind of rela
tion between them. Thus our idea of power may very well be
placed in my opinion among the other simple ideas.
Tit. [At bottom the ideas which we have just enumerated
are composite ; those of sensible qualities hold their place
among the simple ideas only because of our ignorance, and the
others which we know distinctly, keep their place only by an
indulgence which it were better they should not have. It is
almost the same with regard to the common axioms, which
might be and which deservedly should be proved among the
theorems, and which are allowed to pass nevertheless as
axioms, as if they were primitive truths. This indulgence
does more harm than we think. It is true we are not always
in a position to do without it.]
§ 4. Ph. If we consider the matter carefully, bodies do not
furnish us by means of the senses with so clear and so distinct
an idea of active power as that which we have from reflection
upon the workings of our mind. There are, I believe, but two
kinds of actions of which we have an idea, viz. : thinking and
motion. Of thought, body gives us no idea, and it is only
through reflection that we have it. Neither have we from the
body any idea of the beginning of motion.
Tit. [These considerations are most excellent, and although
here I take thought in a manner so general that it includes all
perception, I do not wish to dispute the use of terms.]
Ph. When the body is itself in motion, this motion in the
body is an action rather than a passion ; but when a billiard-
ball yields at the stroke of the cue, it is not an action of the
ball, but a simple passion.
170 LEIBNITZ'S CRITIQUE OF LOCKE |_BK. n
Tli. [There is something to be said upon that point, for the
bodies did not receive motion in the impact, according to the
laws observed therein, if they already had not motion in
themselves. But pass we now this point.]
Ph. The same is true when it pushes another ball which it
finds in its way and puts in motion ; it only communicates to
it the motion it had received, and itself loses just as much.
Th. [I see that this erroneous view, which the Cartesians
have brought into fashion, as if bodies lost as much motion as
they give to others, which is to-day overthrown by experi
ments and by reason, and abandoned moreover by the illustri
ous author of " The Search after Truth," 1 who has published
a brief treatise for the express purpose of retracting it, still
gives scholars occasion to be mistaken in constructing trains
of reasoning upon so ruinous a foundation.]
Ph. The transfer of motion gives us only a very obscure
idea of an active power of motion in the body so long as we
see nothing else than that the body transfers motion but does
not in any way produce it.
Th. [I do not know whether they here maintain that motion
passes from subject to subject, and that the same motion (idem
numero) is transferred. I know that some, contrary to the
view of the entire scholastic philosophy, have gone that far,
among others the Jesuit, Father Casati. But I doubt whether
this is your view or that of your scholarly friends, ordinarily far
removed from such fancies. If, however, the same motion is
not transferred, we must admit that a new motion is produced
in the body which receives it : thus the one which gives
would really act, although it would be passive at the same
time while losing its force. For although it is not true that
the body loses as much motion as it gives, it is always true
that it loses some motion and that it loses as much force as it
gives, as I have elsewhere explained, so that it is always nec
essary to admit in it force or active power. I understand
power in the more noble sense which I have explained a little
before, in which tendency is united with faculty. Nevertheless,
1 Malebranche, De la Recherche de la Veriie, 1G74. The "brief treatise"
referred to is entitled: Traite de la communication da movement, and may
be found in Vol. 3 of the German translation of Malebranche's works, Halle,
1777-80. — TB.
CH xxi] ON HUMAN UNDERSTANDING 177
I am always agreed with you, that the clearest idea of
active power comes to us from the mind. It is also only
in things which are analogous to the mind, that is to say, in
entelechies, for matter properly speaking shows only passive
power.]
§ 5. Ph. We find in ourselves the power to begin or not to
begin, to continue or to end many actions of our soul and
many motions of our body, and this simply by a thought or
choice of our mind, which determines and commands, so to
speak, that such a particular action be done or not done. This
power we call Will. The actual use of this power is called
Volition ; the cessation or production of the action which fol
lows such a command of the soul, is called voluntary, and all
action done without such direction of the soul is called invol
untary.
T/i. [I find all that very good and just. However, to speak
more fairly, and to go perhaps a little farther, I will say that
volition is the effort or tendency (conatus) towards what is
considered good and against that considered bad, so that this
tendency results immediately from the consciousness one has
of them. And the corollary of this definition is this cele
brated axiom : that will and power united, action follows,
since from all tendency action follows when it is not hin
dered. Thus not only the internal voluntary actions of our
minds follow from this conatus, but also the external, that is to
say, the voluntary movements of our bodies, in virtue of the
union of the soul and the body, the reason of which I have
elsewhere given. There are besides the efforts resulting from
the insensible perceptions, of which we are not conscious,
which I prefer to call appetitions rather than volitions (al
though there are also apperceptible appetitions), for those
actions alone are called voluntary of which we may be con
scious, and upon which our reflection may fall when they fol
low the consideration of good and evil.]
Ph. The power of perceiving we call understanding: it in
cludes the perception of ideas, the perception of the signifi
cation of signs, and, finally, the perception of the agreement
or disagreement existing between any of our ideas.
Tli. [We perceive many things within and without us,
which we do not understand, and we understand them, when
N
178 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
we have distinct ideas of them, together with the power of
reflection and of drawing from them necessary truths. Ani
mals therefore have no understanding, at least in this sense,
although they have the faculty of perceiving impressions
more remarkable and more distinct, as the boar perceives a
person who shouts at him, and goes straight for this person, of
whom he had had before only a cloudy perception, but con
fused as of all other objects which fell under his eyes, and
whose rays struck his crystalline humor. Thus in my view
the understanding corresponds to what among the Latins is
called intellectus, and the exercise of this faculty is called
intellection, which is a distinct perception united with the fac
ulty of reflection, which is not in animals. Every perception
united with this faculty is a thought, which I do not accord to
the animals any more than understanding, so that we may say
there is intellection when thought is distinct. For the rest,
the perception of the signification of signs does not deserve
to be distinguished here from the perception of the ideas
signified.]
§ 6. Ph. It is commonly said that the understanding and
the will are two faculties of the soul, a term suitable enough if
used as we ought to use all words, taking care that they cause
no confusion to spring up in the thoughts of men, as I suspect
has happened here in the case of the soul. And when we are told
that the will is that superior faculty of the soul which rules
and orders all things, that it is or is not free, that it deter
mines the lower faculties, that it follows the clictamen of the
understanding ; although these expressions may be understood
in a sense clear and distinct, I fear, however, that they have
caused to arise in many persons the confused idea of so many
distinct agents acting distinctly in us.
T/i. The question has exercised the scholastics a long time
whether there is a real distinction between the soul and its
faculties, and whether one faculty is really distinct from
another. The Realists have said yes, and the Nominalists,
no, and the same question has been agitated as to the reality
of many other abstract entities, which should meet the same
fate. But I do not think we need here decide this question
and plunge into these difficulties, although I remember that
CH. xxi] ON HUMAN UNDERSTANDING 179
Episcopius l found it of such importance that he thought he
could not maintain the freedom of man if the faculties of the
soul w«-e real entities. However, if they were real and dis
tinct entities, they can pass for real agents only in extravagant
speech. It is not the faculties or qualities which act, but sub
stances by means of the faculties.
§ 8. Ph. So long as man has the power to think or to
refrain from thinking, to move or not to move according to
the preference or choice of his own mind, so long he is free.
Th. [The term freedom is very ambiguous. There is free
dom of right and of fact. As regards that of right a slave is
not at all free, a subject is not wholly free, but a poor man is
as free as a rich man. Freedom of fact consists either in the
power to will as one ought, or in the power to do what one wills.
It is of the freedom to do of which you speak, and it has its
degrees and varieties. Generally he who has the most means
is the freest to do what he wills : but in particular freedom is
understood of the use of things which are ordinarily in our
power, and above all, of the free use of our body. Thus the
prison and the diseases which prevent us from giving to our
body and our limbs the motion we wish and which we can
ordinarily give them detract from our freedom : thus a prisoner
is not at all free, and a paralytic has no free use of his limbs.
Freedom of icill is furthermore understood in two different
senses. The first is when it is opposed to the imperfection or
the slavery of the spirit, which is a coactioii or constraint, but
internal like that arising from the passions. The other sense
has place when freedom is opposed to necessity. In the first
sense the Stoics said that the wise man alone is free ; and in
fact the spirit is not at all free when it is filled with a great
passion, for one cannot then will as he should, that is to say,
with the deliberation which is requisite. Thus God alone is
perfectly free, and created spirits are so, only to the extent
that they are superior to their passions. And this freedom
concerns properly our understanding. But the freedom of
spirit, opposed to necessity, concerns the naked will, and in so
far as it is distinguished from the understanding. This is
1 Simon Episcopius, 1583-1(>43. The piece referred to is the De libero ctrbi-
trio, particularly the second chapter; it is found in his Opera Theolofjica, Vol.
1 , p. 198, Div. II., 2d ed. London and Rotterdam, 10(55-1678, 2 vols.. t'ol. — TR.
180 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
what is called free-will (franc arbitre) and it consists in this,
that we will that the strongest reasons or impressions which
the understanding presents to the will do not preventTthe act
of the will from being contingent, and do not give it an abso
lute, and, so to speak, metaphysical necessity. And it is in
this sense that I am accustomed to say that the understanding
can determine the will, according to the prevalence of percep
tions and reasons, in a manner which, even where it is certain
and infallible, inclines without compelling.1
§ 9. Ph. It is well also to consider that no one has yet
thought of taking as a/ree agent a ball, whether in motion by
the stroke of a racket or at rest. This is because we do not
conceive of a ball as thinking or as having any volition, which
makes it prefer motion to rest.
Tli. [If that were //•?<? which acts without hindrance, a ball
once in motion in' a level horizon would be a free agent. But
Aristotle has already well remarked that to call acts free, we
demand not only that they be spontaneous, but further that
they be deliberate.-^
Ph. This is why we consider the motion or rest of balls
under the idea of a necessary thing.
Tli. [The appellation necessary requires as much circumspec
tion as that of free. This conditional truth, viz.: supposing the
ball to be in motion in a level horizon without hindrance, it will
continue the same motion, may pass as in some sort necessary,
although at bottom this consequence is not entirely geometri
cal, being only presumptive, so* to speak, and based upon the
wisdom of God who changes not his influence without a
reason, which it is presumed is not at present to be found.
But this absolute proposition : the ball here is now in motion in
this plane, is only a contingent truth, and in this sense the ball
is a contingent, not a free, agent.^
§ 10. Ph. Suppose that a man, while in a profound sleep, is
carried into a room, where is a person, whom lie much longs to
1 Cf. Essais de Theodicee, Pt. I., §§ 51, 52, Gerhardt, <>, 130-131 ; Erdmann,
517 ; also Eduard Dillmann, Eine neue Darstelluny der Leibnizischen Monad-
enlehre auf Grand der Quellen, pp. 41(5 sq. ; Leipzig: O. R. Reisland, 1891. —
TR.
a Cf. Eth. Nic., III., 4, ad fm.j 5; 1111 sq. ; translation by F. H. Peters,
M.A., London: C. Kegaii Paul & Co., 1881. — TR.
OX HUMAN UNDERSTANDING 181
see and to meet, and that the door is locked upon him ; this
man wakes up and is delighted to find himself with this per
son, and lives thus in the room with pleasure. I think no one
presumes to doubt that he remains voluntarily in that place.
Yet he is not at liberty to go out if he wishes. Thus freedom
is not an idea belonging to volition.
Tli. [I find this example very well chosen to show that in a
sense, an act or a state may be voluntary without being free.
Still when philosophers and theologians dispute upon/ree ivill,
they have altogether another sense in view.]
§ 11. Ph. Freedom is wanting when paralysis prevents the
limbs from obeying the determination of the mind, although,
in the case of the paralytic even, to remain sitting still might
be voluntary so long as he prefers sitting still to changing
his place. Voluntary is not then opposed to necessary, but to
involuntary.
Tli. [This precision of expression would be agreeable enough
to me, but usage is far from it ; and those who oppose freedom
to necessity, mean to speak not of external acts, but of the act
itself of willing.]
§ 12. Ph. A man awake is no more at liberty to think or
not to think, than he is at liberty to prevent or not to prevent
his body from touching any other body. But to transfer his
thoughts from one idea to another is often within his deter
mination. And in that case he is as much at liberty as regards
his ideas, as he is as regards the bodies upon which lie rests,
being able to transfer himself from one to the other as the
fancy arises. There are, however, ideas, w7hich, like certain
(bodily) movements, are so fixed in the mind, that, in certain
circumstances, you cannot avoid them whatever effort you
make. A man upon the rack is not at liberty to put aside the
idea of pain, and sometimes a violent passion acts upon our
mind as the most violent wind acts upon our body.
Tli. [There is order and connection in ideas, as there is in
(bodily) movements, for the one corresponds perfectly to the
other, although the determination in the movements be uncon
scious and free, or with choice in the thinking beinq: whom good
and evil only cause to incline without forcing him. For the soul,
while representing bodies, preserves its (own) perfections, and
although dependent upon the body (in seizing the good) in the
182 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
voluntary acts, it is independent and makes the body depend
upon itself in others. But this dependence is only metapliysical,
and consists in the considerations which God has for the one
while ruling the other, or rather for both, according to the
original perfections of each ; whilst physical dependence would
consist in an immediate influence, which the one would receive
from the other on which it depends. For the rest, there come
to us involuntary thoughts, partly from outside by means of
objects which strike our senses, and partly from within by
reason of the impressions (often insensible) which remain
from preceding perceptions whose action continues and which
mingle with those which appear for the first time. As regards
these we are passive, and even when we wake up, images
(under which designation I include not only the representa
tions of figures, but also those of sounds and other sensible
qualities) come to us, as in dreams, without being called.
The German language calls them ftiegende Gedanken, that is,
flying thoughts (pensees volantes), which are not within our
control, and among which there are sometimes many absurdi
ties which raise scruples in good people, and furnish exercise
to casuists and directors of consciences. It is as in the magic
lantern, which makes figures appear upon the wrall according
as something within is turned. But our mind, perceiving
some image which recurs to it, may say : stop there, and, so to
speak, arrest it. Moreover, the mind enters, as seems good
to itself, into certain trains of thought, which lead it on to
others. But this is true only when internal or external impres
sions do not at all prevail. It is true that in this thing men
differ very much, both according to their temperament and
according as they have exercised their control, so that one can
master impressions where another lets them go.
§ 13. Ph. Necessity takes place wherever thought is wholly
wanting. And this necessity, when found, is an agent capable
of volition, and when the commencement or continuation of
any action is contrary to the preference of his mind, I call it
compulsion; when the hindering or stopping of an action is
contrary to his volition, I may call it restraint. Agents which
have absolutely neither thought nor volition are in all respects
necessary agents.
Th. [It seems to me that, properly speaking, although
CH. xx j] OX IIUMAX UNDERSTANDING 183
volitions are contingent, necessity should not be opposed to
volition, but to contingency, as I have already remarked in § 9,
and that necessity should not be confounded with determina
tion, for there is no less connection or determination in thoughts
than in movements (to be determined being a wholly different
thing from being pushed or forced by compulsion). And if
we do not always notice the reason which determines us or
by which we determine ourselves, it is because we are as
little capable ourselves of perceiving the entire play of our
mind and its thoughts, very often imperceptible and confused,
as we are of recognizing all the machinery which nature causes
to play in the body. Thus, if by necessity, you mean the cer
tain determination of man, which a perfect knowledge of all
the circumstances within and without could make a perfect
mind foresee, it is certain that thoughts being as determined
as the motions they represent, every free act would be a neces
sary act. But necessity must be distinguished from contingency
although determined; and not only are contingent truths not
at all necessary, but further, their connections are not always
of an absolutely necessary character ; for it must be admitted
that there is some difference in the manner of determining
between consequences which take place in necessary matter
and those which take place in contingent matter. Geometrical
and metaphysical consequences necessitate, but physical and
moral incline without necessitating ; the physical even having
something of the moral and voluntary as related to God, since
the laws of movement have no other necessity than that of (the
principle, or choice, of — Tit.) the best. Now God chooses freely
although he is determined to choose the best ; and as bodies
themselves do not choose (God having chosen for them), usage
has decided that they be called necessary agents, to which I am
not opposed, provided we do not confound the necessary and
the determined, and do not suppose that free beings act in
an indeterminate manner, an error which has prevailed in cer
tain minds and which destroys the most important truths, even
this fundamental axiom: that nothing happens icithout reason,
without which neither the existence of God nor other great
truths could be satisfactorily demonstrated. As for compulsion
it is well to distinguish two kinds, the one physical, as when
a man is carried in spite of himself into prison, or thrown
184 LEIBNITZ'S CRITIQUE OF LOCKE [UK. n
down a precipice ; the other moral, as, for example, the con
straint of a greater evil, and this act/ although in a sense
forced, does not cease to be voluntary.2 One may be compelled
also, by the consideration of a greater good, as when a man is
tempted by proposing to him a too great advantage, although it
is not customary to call this constraint.]
§ 14. Ph. Let us see now if we cannot put an end to that
long agitated, and in my opinion very unreasonable, because
unintelligible, question:. Whether man's will ix free or no.
Th. [There is much reason for the exclamation with respect
to the strange manner of men who torment themselves by agi
tating badly conceived questions : They seek for what they know,
and know not for what they seek.~\
Ph. Freedom, which is only a power, belongs only to agents
and cannot be an attribute or modification of the will, which is
itself nothing else than a power.
Th. [You are right, sir, according to the proper use of
words. One can, however, in some measure excuse received
usage. Thus it is customary to attribute power to heat or to
other qualities, i.e. to the body in so far as possessed of that
quality : and in like manner the intent here is to ask if man is
free in willing.]
§ 15. Ph. Freedom is the power a man has of doing or not
doing any act conformably to his will.
Th. If men understood only that by freedom, when they ask
whether the will, or the arbiter is free, their question would be
truly absurd. But you will see presently what they ask, and
indeed I have already touched upon it. It is true but by
another principle, that they (at least many) do not cease to
ask for the absurd and the impossible, in desiring a freedom
of equilibrium absolutely imaginary and impracticable, and
which indeed would not serve them, were it possible for them
to have it, i.e. to have the freedom of willing against all the
impressions which can come from the understanding, which
would destroy true freedom together with the reason, and lower
us below the beasts.
1 Gerhardt reads: " et cette action, qnoyque forcee en quelque facon " ;
Erdmann and Jacques: " car 1'action, qu'elle fait 1'aire," i.e. for the act which
it makes you do. — TR.
2 Cf. Kant, Kritik <L pntkt. Vernunft, Th. I., Bd. I., Hpst. 1, § (>, Anm.;
translation by T. K.Abbott, 1th ed., revised and enlarged. London : Longmans.
1889. — TR.
en. xxi] ON HUMAN UNDERSTANDING 185
§ 17. Ph. He who should say that the power of speaking
directs the power of singing, and that the power of singing l
obeys or disobeys the power of speaking, would express him
self in as proper and intelligent a manner, as he who says, as
has been usual, that the will directs the understanding, and
that the understanding obeys or disobeys the will. § 18.
Nevertheless this manner of speaking has prevailed, and has
caused, if I am not mistaken, much confusion, although the
power of thinking operates no more upon the power of choos
ing and the contrary, than the power of singing upon that of
dancing. § 19. I grant that this or that thought may furnish
man the occasion of exercising his power of choosing and that
the mind's choice may be the cause of its actually thinking on
this or that thing, just as actually singing a certain tune may
be the occasion of dancing such a dance.
Th. [There is a little more than the furnishing of occasions,
since there is some dependence ; for you can will only what
you find to be good, and according as the faculty of under
standing is improved the choice of the will is better, as on the
other hand, according as man has vigor of ivill he determines
his thoughts according to his choice, instead of being deter
mined and carried away by involuntary perceptions.]
Ph. Powers are relations, not agents.
Th. [If the essential faculties are only relations and add
nothing whatever to the essence, the qualities and the faculties
that are accidental or subject to change are something else, and
we may say of these last that the one often depends upon the
other in the exercise of their functions.]
§ 21. Ph. In my opinion the question should not be, whether
the will is free, — that is to speak in a very improper manner,
— but whether the man /,s free. That granted, I say that so
long as any one can by the direction or choice of his mind
prefer the existence of an action to its non-existence, and the
contrary, i.e. can make it exist or not exist according as he
wills, so long he is free. And we can scarcely say how we
could possibly conceive a being freer than so far as he is able
to do what he wills. So that man seems to be as free in refer-
1 Gerhardt reads: "parler," a MS. or typographical error; cf. Locke,
Philos. Works (Bohn's ed.), Vol. 1, p. 370. Erdmann and Jacques read:
"chanter," which the translation follows. — TR.
186 LEIBNITZ'S CRITIQUE OF LOCKE [HK. n
ence to those actions which depend upon this power he finds
in himself, as it is possible for freedom to make him, if I may
so express myself.
Th. [ When we reason about the freedom of the will or upon
free-will (franc arbitre), we do not ask if man can do what
he wills, but if there is enough independence in his will itself.
We do not ask if he has free limbs or elbow-room, but if he
has a free spirit, and in what it consists. In this respect one
intelligence might be freer than another, and the supreme
intelligence will exist in perfect freedom of which creatures
are not at all capable.]
§ 22. Ph. Men naturally inquisitive, and who love to remove
as much as they can from their minds the thought of guilt,
although it be by reducing themselves to a state worse than
that of a fatal necessity, are not, however, satisfied with this.
Unless freedom extends still farther, it is not to their taste,
and in their opinion it is a very good proof that man is not at
all wholly free, unless he has as well the freedom to will as that
of doing what he wills. § 23. Concerning which I believe-
that man cannot be free in reference to this particular act of
willing an action which is in his power, when this action has
been once proposed to his mind. The reason therein is wholly
manifest, for the action depending upon his will, must una
voidably exist or not exist, and its existence or non-exist
ence following without fail exactly the determination and
choice of his will, he cannot avoid willing the existence or
non-existence of this action.
Th. [I should think he could suspend his choice, and that
this happens very often ; above all, when other thoughts inter
rupt deliberation : thus, although the action deliberated upon
necessarily exists or not, it does not at all follow that you
must necessarily determine upon its existence or non-existence ;
for non-existence may happen again for want of resolution.
Thus the Areopagites actually released the man whose case
they had found too difficult to decide, deferring it to a term
far distant, and taking a hundred years to consider it.]
Ph. In making man free in this fashion, I mean in making
the act of willing depend upon his will, another will or ante
rior faculty of volition is necessary in order to determine the
acts of this will, and another to determine that, and thus to
CH. xxi] ON HUMAN UNDERSTANDING 187
infinity ; for wherever you stop, the actions of the last will
could not be free.
Th. [It is true you speak incorrectly when you speak as if
we willed to will. We do not will to will, but we will to do,
and if we willed to will, we should will to will to will, and
this would go on to infinity : meanwhile it is not necessary to
conceal that by some voluntary acts we contribute often indi
rectly to other voluntary acts, and although one cannot will
what he will, as he cannot even judge what he will,1 he can,
however, so act in advance that he judges or wills at the time
what he would wish to be able to will or judge to-day. Men
attach themselves to persons, lectures, and considerations favor
able to a certain party, they give no attention to that which
comes from the opposite party, and by these addresses and a
thousand others which they employ, most frequently without
definite design and without thought, they succeed in deceiving
themselves or at least in changing and converting or per
verting themselves according to what they meet.]
§ 25. Ph. Since then it is evident that man is not at lib
erty to ic ill to ivill or not, the next thing demanded is, whether
man is at liberty to ivill which of the two he pleases, for example,
motion or rest? But this question is in itself so visibly absurd
that it may suffice to convince any one who will reflect that
freedom in no case concerns the will. For to ask whether a man
is free to will what he pleases, motion or rest, speech or silence,
is to ask whether a man can will what he wills, or be pleased
with that with which he is pleased, a question which, in my
opinion, needs no answer.
Th. [It is true, nevertheless, that men find here a difficulty
which deserves to be removed. They say that after having
known and considered all, it is still within their power to will
not only what pleases them the most, but furthermore wholly
the contrary, merely to show their freedom. But you must
consider that this caprice or obstinacy, or at least this reason
which hinders them from following other reasons, also enters
into the balance and makes that please them which would
otherwise not do so, so that choice is always determined by
perception. They do not then will what they would, but what
1 The French is: " et qnoyqu' on ne puisse point vouloir ce qu' on veut,
comrae on ne pent pas meme jnger ce qu' on veut." — Tit.
188 LEIBNITZ'S OIUTIQUE OF LOCKE [BK. n
pleases, although the will can contribute indirectly and as it
were from afar to make anything pleasurable or otherwise, as
I have already remarked. And as men scarcely recognize all
these separate considerations, it is not astonishing that the
mind is so perplexed in regard to this matter which has so
many concealed windings.]
§ 29. Ph. When men ask what it is that determines the
will, the true reply is, the mind. If this answer is not satis
factory, it is plain that the meaning of the question reduces to
this: What moves the mind on each particular occasion to deter
mine to such particular motion or rest its general power of direct
ing its faculties towards motion or rest? To this I reply that
what leads us to remain in the same state or continue the
same action, is solely the present satisfaction we find therein.
On the other hand, the motive which incites to change is
always some uneasiness.
Th. [This uneasiness, as I have shown (in the preceding-
chapter), is not always a displeasure, as ease when found is
not always a satisfaction or pleasure. It is often an insensible
perception, which cannot be distinguished or recognized, which
makes us lean to one side rather than the other, without our
being able to give a reason for so doing.]
§ 30. Ph. Will and desire should not be confounded : a man
desires to be freed from the gout, but understanding that the
removal of this pain may cause the transfer of a dangerous
humor into some more vital part, his will cannot be determined
to any action, which may serve to remove this pain.
Th. [This desire is a kind of an inclination of will (velleite)1
as compared with a complete volition. We should will, for
example, if there were no greater evil to be feared, if we
obtained what we wish, or if perhaps there were a greater
good to be hoped for if we went forward. But we can say
that man wills to be delivered from the gout with a certain
degree of volition, but which does not always go on to the last
effort. This volition is called Velleity when it includes some
imperfection or impotency.]
§ 31. Ph. It is well to consider, however, that what deter
mines the will to act is not the greater good, as is ordinarily
supposed, but rather some actual uneasiness, and ordinarily
1 Cf. New Essays, Book. II., chap. 20, § <>, Ph. and note, ante, p. 168. — TR.
en. xx i] ON HUMAN UNDERSTANDING 189
that which is most pressing. We may give it the name of
desire, which is really an. uneasiness of mind, caused by the
want of some absent good, over and above the desire of being
freed from pain. All absent good does not produce a pain
proportionate to the degree of excellence which it has or which
we acknowledge it to have ; whilst all pain causes a desire
equal to itself; because the absence of good is not always an
evil, as is the presence of pain. Therefore we can look upon
and consider an absent good without pain. But in proportion
as there is anywhere desire, so is there uneasiness. § 32. Who
is there who has not felt in desire what the wise man says
of hope, " that being deferred it makes the heart sick "
(Prov. 13:12) ? Rachel cries "Give me children, or I die"
(Gen. 30:1). §34. When man is perfectly content with
the state he is in, or when he is absolutely free from all
uneasiness, what will can remain to him but to continue
in that state ? Thus the wise Author of our being has
put in men the inconvenience of hunger and thirst and other
natural desires, in order to arouse and determine their wills to
the proper conservation and continuation of their species.
" It is better to marry than to burn," says St. Paul (1 Cor. 7:9).
So true it is that the present sensation of a little burning has
more power over us than the attractions of greater pleasures
looked at in tho distance. § 35. It is true that this maxim,
it is the good and the greatest good which determines the
will, is so firmly established that I am not at all surprised at
having formerly regarded it as beyond doubt. But after strict
inquiry I am forced to conclude that the good and the greatest
good, although judged and acknowledged such, does not deter
mine the will ; unless coming to desire it in a manner propor
tional to its excellence this desire makes us uneasy at our
deprivation of it. Suppose a man convinced of the utility of
virtue so far as to see that it is necessary to the man who pro
poses anything great in this world, or hopes to be happy in
the other : but until this man hungers and thirsts after right
eousness, his will will never be determined to any action in
search for this excellent good, and any other uneasiness com
ing in the way will drag his will to other things. On the
other hand, suppose a man given to wine considers that by
leading the life he leads he is ruining his health and wasting his
loo LEIBNITZ'S CKiTiQn
property, that he is coining to be dishonored in the world, to
bring upon himself disease and to fall at last into poverty
until he no longer has wherewith to satisfy this passion for
drink which so strongly possesses him : nevertheless, the
returns of uneasiness which he feels in being absent from his
companions in debauch, drag him to the tavern at the hours he
has been wont to go there, though at the time he has before
his eyes the loss of his health and estate, and perhaps even
that of the happiness of the other life, happiness which he
cannot regard as a good inconsiderable in itself, since he
admits that it is much more excellent than the pleasure of
drinking or the vain chatter of a company of debauchees. It is
not then for want of casting the eyes upon the sovereign good
that he persists in this intemperance ; for he sees it and
acknowledges its excellence, to the extent that during the
time that intervenes between his drinking hours, he resolves
to apply himself to the search for this sovereign good ; but
when the uneasiness of being deprived of his accustomed
pleasure comes to torment him, this good which he acknowl
edges more excellent than that of drinking, has no longer
power over his mind, and it is this actual uneasiness which
determines his will to the action to which it is accustomed,
and which thereby making very strong impressions prevails
again at the first occasion, although at the same time he binds
himself, so to speak, by secret promises no longer to do the
same thing, and imagines that this will be the last time that
he will act against his highest interest. Thus he finds himself
from time to time reduced to saying:
Video meliora proboque,
Deteriora sequor. 1
i see the better way, I approve it. and I take the worse.
This sentence which we acknowledge as true, and which is
only too well confirmed by a constant experience, is easy to
understand in this way, and there is perhaps no other sense in
which it can be taken.
Tli. [There is something beautiful and solid in these consid
erations. But I would not have you believe on that account
that we must abandon those ancient axioms that the will
HUMAN UNDERSTANDING
follows the greatest good, or that it flies from the greatest evil
that it perceives. The source of the little application to true
goods arises mainly from the fact that in matters and on the
occasions where the senses act but little, the greater part of our
thoughts are, so to speak, surd1 (I call them coyitationes catctn
in Latin) i.e. void of perception and feeling, and consisting
in the wholly empty employment of characters, as happens in
the case of those who make algebraic calculations without con
sidering from time to time that the geometrical figures in
question and the words ordinarily produce the same effect in
this regard as the characters of arithmetic or algebra. One
often reasons in words without having quite the same object
in mind. Now this knowledge cannot move ; something living
is necessary in order to arouse us. But thus it is that men
most frequently think of God, of virtue, of happiness ; they
speak and reason without definite ideas. Not that they can
not have them, since they are in their mind. But they do not
trouble themselves to press their analysis. Sometimes they
have ideas of an absent good or evil, but very feeble. It is
then no wonder that they are scarcely affected. Thus if we
prefer the bad it is because we perceive the good which it
includes without perceiving either the bad therein or the good
in tho contrary consideration. We assume and believe, or
rather we make the statement merely upon another's belief, or
at most upon belief in the memory of our past reasonings, that
the greatest good is on the better side, or the greatest evil on
the other. But when we do not look at these at all, our
thoughts and reasonings contrary to the feeling are a kind of
pxittdfixin ~ which furnishes nothing at present to the mind ;
and if we take no measures to remedy it, it is idle talk, as 1
have already remarked above (Bk. 1., chap. 2, § 11), and the
most beautiful precepts of morality together with the best
rules of prudence take effect only in a soul which is sensible
(cither directly, or, because that cannot always be, -at least i»-
((ir<-<'tlj{, as I shall show presently) and which is no longer
sensible to that which is contrary thereto. Cicero well says
i The French is: "sourdes/' Cf. p. 10H, near the end of Th. — TR.
'2 Littre' thus defines " psittacisme," quoting this passage and the one further
on. § .".7, Th., by way of illustration: " Etat dYsprit dans lequel on ne pense on
T i.arle qn'en perroqnet," i.e. a state of the mind in which one thinks or
> • .ui,s only as a parrot. — Tit.
192 LEIBNITZ'S CRITIQUE OF LOCKE [nit. n
somewhere l that if our eyes could see the beauty of virtue, we
should love it warmly ; but that not being at all the case, nor
anything equivalent, we must not be astonished if in the strug
gle between the flesh and the spirit, the spirit so many times
yields, since it does not clearly perceive its advantages. The
struggle is nothing else than the opposition of different ten
dencies, which spring from confused and distinct thoughts.
Confused thoughts often make themselves clearly felt, but
our distinct thoughts are ordinarily clear only potentially ;
they might be clear, if we would apply ourselves to the
penetration of the sense of the words or characters ; but not
doing so, either through negligence, or because of the shortness
of time, we oppose mere words, or at least, too feeble images
to living feelings. I knew a man influential in church and
state, whose infirmities made him resolve to diet ; but he ad
mitted that he had not been able to resist the odor of the
viands, which, passing before his apartment, were carried to
others. It is doubtless a disgraceful weakness, but it is just
what men have done. But if the mind made good use of its
advantages, it would triumph grandly. It would be necessary
to begin with education, which should be so regulated as to
render true good and true evil as sensible as possible, by in
vesting the notions which are formed of them with circum
stances more suited to this design; and a full-grown man who
lacks this excellent education should commence rather late,
than never, to seek pleasures enlightened and reasonable, in
order to oppose them to those of the senses, which are con
fused but impressive. And in fact, divine grace itself is a
pleasure 2 which gives light. Thus when a man is in the midst
of good impulses, he ought to make laws and regulations for
1 Perhaps in De Fin., 2, 16, § 52: " Oeulorum, inquit Plato, est in nobis
sensus acerrimus, quibus sapientiam non cernimus. Quain ilia ardentes amores
excitaret sui, si videretur," where, however, the discourse is concerned with
the particular virtue of wisdom, rather than with virtue in general. The pas
sage of Plato referred to is in the Phsedrus, 250 D. Of. also, De Off., 2, 37:
" Quis non admiretur splendorem pulchritudinemque virtutis " ; and De Off.,
1, 5: " Formam quidem ipsam, Marce fili, et tanquam faciem honest! vides;
quse si oculis cerneretur, mirabiles amores excitaret sapientiae." — TR.
2 Cf. Spinoza, Ethica, Part V., Props., 32, 33, sq. ; translation by R. H. M.
Elwes, The Chief Works of Benedict de Spinoza, Vol. 2, pp. 2(53 sq. (Bonn's
Philos. Library), London: George Bell & Sons, 1884. The best edition of
Spinoza's Works is that of Van Vloten and Land, The Hague, 1882-1883. — Tn.
CH. xxi] ON HUMAN UNDERSTANDING 193
the future, and execute them rigorously, tearing himself away
from those causes able to corrupt him, either brusquely or
gradually, according to the nature of the circumstances. A
journey expressly undertaken will cure a lover; a retreat will
draw us from the companions who support us in some bad in
clination. Francis of Borgia, General of the Jesuits, who has
at last been canonized, being wont to drink largely when he
was a man in high life, reduced himself little by little upon a
small scale, when he thought of retiring (from the world) by
causing a drop of wax to fall daily into the bottle which he
was wont to empty. To dangerous sensibilities we shall op
pose some other innocent sensibility, as agriculture, garden
ing ; we shall shun idleness ; we shall collect curiosities of
nature and art ; we shall make experiments and researches ;
we shall engage in some indispensable occupation, if we have
none, or in conversation, or useful and agreeable reading.
In a word, we must profit from good impulses as from the
voice of God which summons us to make effective resolutions.
And as we cannot always analyze the notions of true goods
and true evils until we perceive the pleasure and pain they in
clude, we must once for all make this law in order to be moved
by them : to attend to and follow henceforth the conclusions
of reason once for all understood, although perceived after
ward and ordinarily only by thoughts surd1 merely, and desti
tute of sense attractions ; and this in order to put yourselves
finally in possession of control over the passions as well as of the
insensible inclinations or uneasinesses, by acquiring this habit
of acting according to reason, which makes virtue pleasant,
and as it were natural. But it is not our business here to give
and teach the precepts of morality, or the spiritual directions
and address for the exercise of true piety ; it is enough that
in considering the procedure of our soul, we see the source of
our weaknesses, the knowledge of which gives, at the same
time, that of their remedies.]
§ 36. Ph. The present uneasiness which presses us, works
only upon the will, and naturally determines it in view of that
happiness to which we all aim in all our actions ; because every
one regards pain and uneasiness (i.e. the restlessness, or rather
inconvenience, which prevents us from being at our ease) as
1 Cf. p. 191, near the beginning of Th., and note. — TR.
104 LKIBMTZ'S CRITIQUE OF L<>CKK
incompatible with happiness. A little pain suffices to corrupt
nil the pleasures we enjoy. Consequently that which deter
mines incessantly the choice of our will to the succeeding
action will always be the removing of pain, as long as we fed
any touch of it ; this removal being- the first step towards
happiness.
Th. If you take your uneasiness or inquietude as a veritable
displeasure, in this sense I do not admit that it is the sole in
centive. Most frequently these are the little insensible per
ceptions which might be called imperceptible pains if the,
notion of pain did not include cqrperc^ption. These little im
pulsions consist in delivering themselves continually from
little obstacles towards which our nature works without think
ing of them. This uneasiness consists in truth in this, that
we feel without knowing it, which fact makes us act in passion
as well as when we appear most tranquil ; for we are never
without some action and motion, which arises only from the
fact that nature always labors to put herself more at her ease.
And this it is which determines also before all consultation in
the cases ichidi appear to us the most indifferent, because we are
never perfectly in suspense and we cannot be exactly equally-
divided between two cases. Now if these elements of pain
(which degenerate into veritable pain or displeasure sometimes
when they overgrow) were true pains, we should always be
miserable in pursuing the good that we seek with uneasiness
and spirit. But it is wholly the contrary; and as I have
already said above (§ 6 of the preceding chapter), the mass
of these continual little successes of nature, which puts it more
and more at ease in reaching for the good and enjoying its
image, or lessening the feeling of pain, is already a consider
able pleasure, ajid often worth more than the enjoyment even
of the good; said very far from being obliged to regard thts un
easiness as incompatible with happiness, I find that uneasiness is
essential to the happiness of created beings which never con
sists in complete possession,1 — this makes them insensible, and
1 Cf. the famous passage of Lessing, 1729-1781, regarding the ' search after
truth, rather than its possession,' in the The<>lo</. Streitschriften, Eine Duplik.
1778, I. ad fin., Werke, Bd.10, s. 19, Stuttgart, 1S(>5): " Xieht die Wahrheit, in
deren Besitz irgend ein Menseh ist. oder zu sein vermeint, sondern di«- ant-
rirhtige Miihe, die er ange\vandr hat, hinter die Wahrheit /u kommen. nun-ln
den Werth des Mensrhen. I)enn nicht dmvh den Besitx, sondern duivh die
en. xxi] ON HUMAN UNDERSTANDING 1!>5
as it were stupid, — but in a progress continuous and uninter
rupted towards the greatest good, which cannot fail to be ac
companied by a desire, or at least, a continual uneasiness, but
which, as 1 have just explained, does not go so far as to incon
venience, but limits itself to those elements or rudiments of
pain, partly unconscious, which do not cease to be sufficient to
serve as an incentive and to arouse the will ; as does appetite
in a man who is well when it does not go to that inconvenience
which makes us impatient and torments us by a too great at
tachment to the idea of what we lack. These appetitions, small
or great, are what are called in the schools motus primo primi,
and are truly the first steps which nature makes us take not
so much towards happiness as towards joy, for they relate only
to the present ; but experience and reason teach us to rule
these appetitions and to control them so that they may con
duce to happiness. I have already spoken to 'this effect (Hook
I., chap. 2, § 3}. The appetitions are like the natural ten
dency of the stone, which goes the most direct, but not always
the best path towards the centre of the earth, not being able
to see beforehand that it will meet rocks upon which it will
break in pieces, whilst it would approach its end more directly
if it had mind and the means of turning aside from them.
Thus it is that going straight towards present pleasure we
sometimes fall over the precipice of misery. Hence, reason
opposes thereto images of the greatest good or evil to come,
and a firm resolution and habit of thinking before acting, and
then of following what shall have been recognized as the best,
Xachforschung der Wahrheit erweitern sich seine Kriifte, vvorin allein seine
iinmer wachsende Vollkommenheit besteht. Der Besit/ maeht ruhig, trilge,
stolz . . ." ; i.e. '' Not the truth, in possession of which at any time a man is,
or thinks he is, but the .genuine effort he has made to disc-over the truth, con
stitutes the worth of the man. For not through possession, but through the
search after the truth, are his powers expanded, wherein alone consists his ever
growing perfection. Possession makes (him) quiet, lazy, proud . . ."
The real significance of this famous passage in relation to the problem of
knowledge is not that knowledge is impossible, i.e.. Agnosticism, for this is
strictly the meaning of the term ; but rather that the attainment of truth is
possible, and that the human mind, having in its very constitution infinite
dements and a capacity for an infinite ideal, can never rest satisfied with any
1 »resent attainment or form of expression a,s final, but must continue to strive
after the perfect truth as embodied in the infinite. ('/. an article by the
Translator, entitled " Revelation, Inspiration, and Authority," in '• The Andover
Review," April, 1S91 . -— TR,
196 LEIBNITZ'S CRITIQUE OF LOCKE [BK. u
even when the sensible reasons of our conclusions are no longer
present in the mind, and consist of scarcely more than feeble
impressions or even of sard thoughts, which give words or
signs destitute of an actual explanation, so that all consists in
the: Consider it well, and in the: Be mindful; the first in
order to the making of laws, the second for their following,
even when you do not think of the reason which has called
them into existence. It is, however, well to think of them as
much as possible, in order that the soul may be filled with a
rational joy and a pleasure accompanied with light.]
§ 37. Ph. These precautions are doubtless so much the
more necessary as the idea of an absent good can counter
balance the feeling of some uneasiness or displeasure by which
we are at present tormented, only so far as this good arouses
any desire in us. How many men there are to whose minds
the unspeakable joys of paradise are represented' by lively
pictures which they recognize as possible and probable, who
nevertheless would willingly content themselves with the hap
piness which they enjoy in this world. It is the uneasiness of
their present desire getting the better of them and bearing
them rapidly towards the pleasures of this life which deter
mines their wills to seek them : and during all this time, they
are wholly insensible to the goods of the other life.
Tli. [This arises in part from the fact that men very often
are but little persuaded ; and, although they say they are, a
hidden unbelief reigns in the depths of their souls ; for they
have never understood the excellent reasons which verify this
immortality of souls, worthy of the justice of God, which is
the foundation of true religion, or rather they no longer re
member that they understood them, one or the other of which
conditions however is necessary in order to conviction. Few
men indeed think that the future life, as true religion and
indeed true reason teaches it, is possible, and they are still
farther from thinking it probable, not to say certain. All that
they do think about it is but a psittacism, or gross and vain
images after the Mahometan fashion, in which they them
selves see little likelihood. For they are very far from being
moved by them, as (according to report) were the soldiers
of the Prince of the Assassins, the Old Man of the Moun-
CH. xxi] ON HUMAN UNDERSTANDING 197
tain,1 who were carried away wrhen fast asleep into a place full
of delights, where, believing themselves in the paradise of Ma
homet, they were imbued by the angels or counterfeit saints with
such opinions as this prince desired, and whence after having
been stupefied anew they were carried to the place whence they
had been taken; this emboldened them afterwards to undertake
everything, even attempts upon the lives of princes, enemies of
their chief. I do not know whether this Lord2 or Old Man of the
Mountain was injured ; for not a few great princes may be named
whom he had caused to be assassinated, although you may see
in the English historians the letter, attributed to him, exon
erating King Richard I. of the assassination of a Count or
Prince of Palestine,3 whom this Old Man of the Mountain ad
mitted he had had killed because he had been insulted by him.
1 The usual translation of " Sheikh-al Jebal," the title of the supreme ruler
of the Assassins, a secret society whose distinguishing feature was the employ
ment of secret assassination against all enemies ; a practice introduced by
Hassan Ben Sabbah, the first chief of the sect. Otherwise the principles of
the society were the same as those of the Ismaelites, viz. 1. No fixed rules
of religion or morality, all actions indifferent, internal disposition alone of
value. 2. Belief that the Immams of Ismael's line were now invisible, hence
implicit obedience on part of true believers due to their vicegerents on earth.
3. Allegorical interpretation of the Koran, defending or rejecting any doctrine
at pleasure, as occasion required.
The society was made up of seven ranks or orders: 1. The Sheikh ; 2. the
Daial-Kirbal, or grand-priors; 3. the Dais, or priors; 4. Refiks, associates
not initiated, as were the former, into all the secret doctrines: 5. the Fedais,
"devoted ones," a band of youths uninitiated and blindly obedient to the
chief; (i. Lasiks, or novices; 7. common people, laborers, and mechanics. On
these was enjoined the most rigid observance of the Koran. The initiated
regarded all positive religion and morality as worthless. The Fedais were the
assassins proper. Whenever the chief wished for their service he had them
intoxicated with hashish, or the hemp-plant, and transported into his splendid
gardens, where they were surrounded with every sensual pleasure, and by this
foretaste of Paradise which the chief alone could grant led to obey his slightest
command implicitly, even to the surrender of their own lives. From this cir
cumstance they were called Hashishin, or hemp-eaters. This word the Euro
peans changed into Assassins, and thus it was transplanted into the Western
languages with the signification of murderers. See Von Hammer, Geschirhte
der Assassinrn, 1818; Michaud, Hixtoire des Croisadcs, 2, pp. 465-484;
F. Walpole, The Ansaj/rii, or Assassins, 3 vols., 1851; Gayard, Fragments
relatifx a la Doctrine des Ismaelis, 1874; De Sacy, Memoires de V Institat, 4,
1818, discusses the etymology fully. — TR.
2 Gerhardt reads : " Seigneur ou Senior (Vieux) de la Montagne." — TR.
3 The Margrave Conrad of Montferrat, one of Saladin's brave adversaries.
Cf. Gibbon, Decline and Fall, Milman's ed., chap. 5*), and note 74, also Milman's
note ; Weil, Gesch. d. Chalifcn, Vol. 3, p. 423; Wilken, Gesch. d. Kreuzziige,
Vol.4, p. 485.S9. — TR.
11)8 LEIBNITZ'S CKITIQL'E OF LOCKE [MK. n
Although that may be so, it was perhaps because of his great
zeal for his religion that this Prince of the Assassins wished
to give his people a favorable idea of paradise which should
always accompany their thoughts of it and prevent them
from being surd; without claiming on that account that they
should believe that they had been in paradise itself. I>ut
supposing he had made this claim, it would not necessarily be
astonishing if these pious frauds had been more efficacious than
the truth badly managed. Yet nothing would be stronger than
truth if we devoted ourselves to its complete knowledge and
cultivation ; and we should have in it without doubt the means
of strongly influencing men. When I consider how much
ambition or avarice can accomplish in all those who once
place themselves in this course of life, almost destitute of sen
sible and present attractions, I despair of nothing, and 1 hold
that virtue would be infinitely more effective accompanied as
it is by so many solid goods, if some happy revolution of the
human race brought it for a day into demand and made it as
it were fashionable. It is very certain that we could accustom
the youth to find their greatest pleasure in the practice of vir
tue. And even grown up men could make themselves laws
and a habit of conforming to them, which would influence them
as strongly and with as much uneasiness if they were tun KM!
aside from them, as a drunken man would feel when he is
prevented from going to the ale-house. I am very happy to
add these considerations upon the possibility and even upon the
ease of the remedies for our evils, in order not to assist in dis
couraging men from the pursuit of true goods by the men1-
exposition of our weaknesses.]
§ 39. Pit. [Xearly everything consists in making constant
the desire for true good.] And it rarely happens that any
voluntary action is produced in us unless some dexire accom
panies it; this is why ivill and desire are so often confounded.
Hut we must not regard the uneasiness which makes a part of.
or which at least accompanies most of the other passions, as
entirely excluded in this case. For hatred, fear, anger, envy,
shame, have each their uneasiness, and thereby influence the
will. I doubt if any one of these passions exists entirely alone.
1 believe indeed that it would be difficult to find any passion
unaccompanied by dexfre. I am sure, however, that wherever
rn. xxi] ON HUMAN rXDKKSTANDlNlr 100
there is uneasiness there is desire. And as our eternity does
not depend on the present moment, we look beyond the present,
whatever be the pleasures which we actually enjoy, and desire,
accompanying these glances anticipative of the future, always
impels the will to follow ; so that even in the midst of joy
that which maintains the action upon which the present pleas
ure depends, is the desire to continue it, and the fear of being
deprived of it, and whenever a greater uneasiness than that
takes possession of the mind it immediately determines the
mind to a new action and the present pleasure is neglected.
T/i. [Many perceptions and inclinations concur in perfect
volition, which is the result of their conflict. There are
some imperceptible by themselves, whose mass makes an un
easiness which impels us without our seeing the cause; there
are many joined together which tend to some object or which
remove it, and then it is desire or fear accompanied also by
an uneasiness, but which does not always go so far as pleasure
or displeasure.1 Finally, there are impulses really accompanied
by pleasure and by pain, and all these perceptions are either
new sensations or ideas resting upon some past sensation
(accompanied or not by memory), which renewing the attrac
tions these same images had in the preceding sensations, renew
also the former impulses in proportion to the vividness of the
idea. From all these impulses results at last the prevailing
effort which makes the will complete. 'But the desires and
tendencies which are perceived are often also called voli
tions though less complete, whether they prevail and influence
or not. It is thus easy to believe that volition can have but
little force without desire and without aversion (fuite) ; for
such I believe we may call the opposite of desire. Uneasi
ness exists not only in the troublesome passions, as hatred,
fear, anger, envy, shame, but further in their opposites, as
love, hope, favor, and glory. We may say that whenever
there is desire, there will lie uneasiness; but the contrary is
not always true, because often one is in a state of uneasiness
without knowing what lie wants, and then there is no full-
grown desire.]
55 40. Ph. Ordinarily the most pressing of the uneasinesses
1 (Jei-lianlt ;i<Ms: "on deplaisir.'' — TK.
200 LEIBNITZ'S CKITIQUE OF LOCKE [UK. n
which are judged capable of being removed at that time deter
mines the will to action.
Th. As the result of the balance makes the final deter
mination, I should think it may happen that the most press
ing uneasiness does not prevail; for though it might prevail
over each of the opposed tendencies taken by themselves, the
others united may overcome it. The mind can indeed use
skilfully the dichotomies in order to cause sometimes the one,
sometimes the others, to prevail, as in an assembly we can
cause one party to prevail by plurality of votes, according as
we shape the order of the question. It is true the mind
ought to look far into the future ; for in the moment of
struggle there is no time to use these artifices. All that then
makes an impression, bears hard upon the balance, and helps
to form a compound direction almost like that in mechanics,
and which without some prompt diversion we cannot stop.
Fertur equis auriga iiec audit currus habenas.1
§ 41. Ph. If you ask further lohat it is that arouses desire,
I reply, happiness and nothing else. Happiness and misery
are the names of two extremes of whose utmost bounds we
are ignorant. It is what "eye hath not seen, ear hath not
heard, and the heart of man hath never conceived." 2 But both
make in us lively impressions by means of different kinds
of satisfaction and joy, of torment and sorrow, which for
brevity's sake I comprehend under the names of pleasure and
pahij both of which happen to the mind as well as to the
body, or, to speak more accurately, pertain only to the mind,
although sometimes they originate in 'the mind upon the
occasion of certain thoughts, and sometimes in the body
from certain modifications of motion. § 42. Thus happiness,
taken in its full extent, is the utmost pleasure of which we are
capable, as misery, taken in the same way, is the greatest
pain we can feel. And the lowest degree of what can be
called happiness is that state, in which delivered from all
pain, we enjoy such measure of present pleasure that we can
not be content with less. We call that a good which is
adapted to produce in us pleasure, and we call that an evil
which is adapted to produce in us pain. But it often happens
1 Verg. Georg. 1 : 514. — TB. 21 Cor. 2:9. — TR.
en. xxi] OX HUMAN UNDERSTANDING 201
that we do not so name it when one or another of these goods
or of these evils is found in competition with a greater good
or a greater evil.
Th. [I do not know whether the greatest pleasure is possi
ble. I should think rather that it can grow infinitely ; for
we know not how far our knowledge and our organs may
be carried in all that eternity which awaits us. I should
think then that happiness is a lasting pleasure ; which can
not exist without a continual progression to new pleasures.
Thus of two, one of whom will advance incomparably more
rapidly and by greater pleasures than the other, each will be
happy in himself although their happiness will be unequal.
Happiness is then so to speak a road through pleasures, and
pleasure is only a step and an advance towards happiness, the
shortest that can be made according to present impressions,
but not always the best, as I said towards the end of § 36.
One may miss the true road, in desiring to follow the short
est, as the stone going straight may meet too soon obstacles
which prevent it from advancing directly towards the centre
of the earth. Thus we know that it is the reason and the
will which lead us towards happiness, but that feeling and
appetite carry us only towards pleasure. Now although
pleasure cannot receive a nominal 1 definition, any more than
light or color, it can nevertheless receive like them a causal,1
and I believe that at bottom, pleasure is a feeling of perfec
tion and pain a feeling of imperfection, provided it be marked
enough to make us capable of perceiving it : for the little
insensible perceptions of a perfection or imperfection, which
are like the elements of pleasure and pain, and of which I have
spoken so many times, form the inclinations and propensities,
but not yet the passions themselves. Thus there are insensi
ble inclinations and these we do not perceive; there are sensi
ble ones whose existence and object we know, but whose
formation we do not feel, and there are confused inclinations
which we attribute to the body, although there is always
something corresponding in the mind ; finally, there are dis
tinct inclinations, which reason gives us, whose force and
formation we feel ; and the pleasures of this kind which are
found in the knowledge and production of order and harmony
1 Cf. Neic Essays, Bk. III., chap. 3, § 18. — TR.
20i' LK1 KMT/AS CRITIQUE OF LOCKE [HK. n
are rhe most estimable. You are right in saying that in
general all these inclinations, passions, pleasures and pains
belong only to the mind or soul ; I will add, indeed, that their
origin is in the soul itself, taking things in a certain meta
physical strictness, but that, nevertheless, you are right in say
ing that confused thoughts come from the body, because
thereupon the consideration of the body — and not that of
the soul — furnishes something distinct and explicable. The
good is that which conduces or contributes to pleasure, as the
evil is, that which contributes to pain. But in collision with a
greater good, the good of which we should be deprived would
become in truth an evil, in so far as it should contribute to
the pain which would spring from it.
$ 47. Pit. The soul has the power of suspending the accom
plishment of some of these desires, and is consequently at lib
erty to consider one after another and to compare them. In
this consists the freedom of man, and what we call, though in
my view improperly, free-will ; and it is from the bad use we
make of it that all this variety of mistakes, errors, and faults
proceeds, into which we rush when we determine our will too
promptly or too late.
Th. The execution of our desire is suspended or stopped
when this desire is not strong enough to move us and to over
come the trouble or inconvenience there is in satisfying it ;
and this trouble consists sometimes only in an inactivity or
insensible lassitude which discourages without our taking
notice of it, and which is greatest in persons reared in indo
lence or whose temperament is phlegmatic, and in those who
are discouraged by age or by poor success. But when desire
is strong enough in itself to move, if nothing prevents it, it
can be stopped by contrary inclinations ; whether they consist
in a simple propensity which is as it were the element or be
ginning of desire, or go as far as desire itself. But as these
inclinations, these propensities, and these contrary desires are
to be found already in the soul, it does not have them in its
power, and consequently it could not resist them in a free and
voluntary way in which the reason can share, if it had no
other means of diverting the mind elsewhere. But how does
it presume to do it in case of need ? For there is the point,
especially when one is occupied with a very strong passion.
en. xxi ] ON HUMAN UNDERSTANDING 203
It is then necessary for the mind to be prepared in advance1,
and to find itself already in process of going from thought to
thought, in order not to hesitate too much at a slippeiy and
dangerous step. It is well for that reason to accustom our
selves in general not only to think as it were in passing of
certain things in order the better to preserve the freedom of
the mind; but it is better to accustom ourselves to proceed
methodically, and to fasten ourselves to a train of thoughts
whose connection reason and not chance (i.e. insensible and
casual impressions) makes. And for this purpose it is well
from time to time to accustom ourselves to collect our thoughts
and to raise ourselves above the present tumult of impres
sions, to go forth, so to speak, from the place where we are, to
say to ourselves: ''Die cur hie? respice fine/in? where are we
then '/ or let us come to the purpose,- let us come to the point.''
Men would very often need some one officially appointed (as
IMiilip, the father of Alexander the Great, had) to interrupt
and call them to their duty. But in default of such an officer,
it is well for us to be accustomed to render ourselves this ser
vice. Xow being once in a condition to stop the effect of our
desires and passions, i.e. to suspend (their) action, we can find
means to combat them, whether by contrary desires or inclina
tions or by diversion, i.e. by occupations of another nature.
It is by these methods and artifices that we become as it were
masters of ourselves, an<,l can make ourselves think and do at
the time what \ve should wish to will and what reason com
mands. But it is always through determined paths, and never
without a reason or by means of the imaginary principle of
perfect indifference or equilibrium, in which some would make
the essence of freedom to consist; as if one could determine
himself without a subject, and even against every subject, and
go directly against the entire prevalence of impressions and
propensities. Without a reason, I sav. i.e. without the opposi
tion of other inclinations, or without being in advance dis
posed to turn aside the mind, or without any other means
equally explicable : (to act) otherwise is to recuv to the chimer-
: Literally: Why arc \ve here? Consider the end ! — TR.
- Erdmann and Jacques omit: "<m venous au propos," found in Ger
hard r. — TK.
204 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
ical, as in the empty faculties or occult qualities of the scho
lastics, in which there is neither rhyme nor reason.]
§ 48. Ph. [I am also for this intelligent determination of
the will by what is in the perception and the understanding.]
To will and do conformably to the final result of a sincere
examination is rather a perfection than a defect of our nature.
And this so far from being a suppression or an abridgement
of freedom, is its greatest perfection and advantage. And the
more we are prevented from determining ourselves in this
way, the nearer we are to misery and slavery. In fact, if you
suppose in the mind a perfect and absolute indifference which
cannot be determined by the final judgment which it makes of
good or evil, you put it in a very imperfect state.
Tli. [All this is very much to my taste, and shows that
the mind has not entire and direct power always to stop its
desires, else it would, never be determined, whatever examina
tion it might make, and whatever good reasons or efficacious
sentiments it might have, and it would always remain irreso
lute and fluctuate eternally between fear and hope. It must,
then, after all, be determined, and thus it could itself oppose
only indirectly its desires, by itself preparing in advance the
arms which fight them in time of need ; as I have just ex
plained.]
Ph. But a man is at liberty to lift his hand to his head or
to let it lie quiet. He is perfectly indifferent regarding either
of these acts, and it would be an imperfection in him if he
lacked that power.
Th. [To speak accurately, one is never indifferent regard
ing two alternatives,1 whatever they may propose ; for exam
ple, turning to the right or the left,2 putting the right foot
forward (as was necessary in the case of Trimalchio) or the
left ; for we do the one or the other without thinking of it,
and this is an indication that a concurrence of internal disposi
tions and external impressions (although insensible) deter
mines us to the side that we take. But the prevalence is very
1 After "partis," Gerhardt reads: "quelsqu'on puisse proposer," which
Erdmann and Jacques omit.- — TR.
2 After " gauche," Gerhardt reads : " de mettre le pied droit devant (comme
il falloit chez Triraalcion) on le gauche, "which Erdmann and Jacques omit.
For the allusion cf. Petronius, Satyricon, chap. 30. — TR.
CH. xxi] ON HUMAN UNDERSTANDING 205
small, and in case of need it is as if we were indifferent in this
respect, since the least sensible subject which presents itself
to us is capable of determining us without difficulty to one
rather than to the other; and although there is a little trouble,
in lifting the arm to raise the hand to the head, it is so small
that we overcome it without difficulty ; otherwise, I admit it
would be a great imperfection if man were less indifferent,
and if he were wanting in power to determine easily to raise
or not to raise his arm.]
Ph. But it would be as great an imperfection if lie had the
same indifference on all occasions, as when he would defend
his head or his eyes from a blow, by which he saw he was
about to be struck. [That is to say, it were as easy for him
to stop this movement as others of which we have just spoken,
and in which he is almost indifferent ; for that would make
its influence insufficiently strong and prompt in time of need.
Thus determination is useful to us, and, indeed,1 very often
necessary ; for if, we were less determined on every sort of
occasion, and as it were insensible to reasons drawn from the
perception of good or evil, we would be without effective
choice.] And2 if we were determined by something else than
the final result, which we have formed in our own mind accord
ing as we have judged a certain action good or evil, we should
not be free.
Tli. [Nothing is truer, and those who seek another free
dom know not what they ask.]
§ 49. Ph. The superior beings who enjoy perfect happi
ness are determined in the choice of the good more strongly
than we, and yet we have no reason to think them less free
than ourselves.
Tli. [For this reason theologians say that these blessed
substances are confirmed in the good and exempt from all
danger of falling.]
Ph. I believe indeed that, if it were proper for poor finite
creatures like ourselves to judge of what an infinite wisdom
and goodness could do, we could say that God himself can
not choose what is not good, and that the freedom of this all
1 Gerhardt omits "ineme," which Erdmann and Jacques insert after
"et."— TR.
2 Gerhardt reads : "it"; Erdmann and Jacques, " comme." — TR.
206 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
powerful being does not hinder him from being determined by
what is best.
Th. [I am so persuaded of this truth that I believe we can
boldly assure ourselves of it, wholly poor and finite creatures
that we are, and that we should be very wrong in doubting
it; for by so doing we should derogate from his wisdom,
goodness and other infinite perfections. But choice, however
determined the will be, should not be called necessarily and
rigorously absolute; the prevalence of perceived good in
clines without necessitating, although considered as a' whole,
this inclination is determinate and never fails to produce its
effect.]
§ 50. Ph. To be 'determined by the reason to the best,
is to be the freest. Who would wish to be foolish for the
reason that a fool is less determined by wise reflections than
a man of good sense ? If freedom consists in throwing off
the yoke of reason, fools and madmen will be the only free
men ; but I do not believe that for love of such freedom
any one would wish to be a fool, save he who is one already.
Th. [There are people to-day who consider it clever to
declaim against reason, and to treat it as an inconvenient
pedant. I see little books, discourses about nothing, which
make great pretensions, and I sometimes see verses even too
beautiful to be employed in such false thoughts. In fact,
if those who mock at reason spoke in earnest, it would be a
new kind of extravagance unknown to past centuries. To
speak against reason is to speak against truth ; for reason is a
concatenation of truths. It is to speak against one's self,
against one's good, since the principal point of reason con
sists in knowing the truth and following the good.]
§ 51. Ph. As then the highest perfection of an intelligent
being consists in applying himself carefully and constantly to
the search for true happiness, so the care we should employ
not to take as real happiness that which is only imaginary, is
the foundation of our freedom. The more we are bound to
the invariable search for happiness in general winch never
ceases to be the object of our desires, the more our will finds
itself freed from the necessity of being determined by the
desire which bears us towards some particular good, until we
have examined whether it agrees with or is opposed to our
true happiness.
CH. xxi] ON HUMAN UNDERSTANDING 207
Tit. The true good should always be the object of our
desires, but there is room for doubt whether it is so : for often
one thinks but little of it, and I have remarked here more
than once, that unless appetite is guided by reason it tends to
present pleasure and not to happiness, i.e. to enduring pleas
ure, although it tends to protract it ; see § 36 and § 41.
§ 53. Ph. If some extreme disturbance takes entire pos
session of our mind, as the pain of a cruel torture, we are not
enough masters of our mind. But in order to control our
passions as much as possible, we should make our mind relish
good and evil really and effectively, and not permit an ex
cellent and considerable good to escape our mind without leav
ing there some relish, until we have excited in ourselves
desires proportioned to its excellence so that its absence
renders us uneasy as well as the fear of losing it when we
enjoy it.
Tli. [That sufficiently agrees with the remarks I have
just made in §§ 31 and 35, and with what I have said more
than once of luminous pleasures, where we understand how
they improve us without putting us in danger of some greater
imperfection, as do the confused pleasures of sense, against
which we must guard ourselves, especially when we have not
learned by experience that we shall be able surely to avail
ourselves of them.]
Ph. And let no one say here that he cannot master his pas
sions nor hinder them from breaking loose and forcing him to
act; for what he can do before a prince or great man, he can
do, if he will, when alone or in the presence of God.
Tli. [That remark is very good and worthy of frequent
reflection.]
§ 54. Ph. But the different choices men make in the world,
prove that the same thing is not equally good for each of
them. And if the interests of men did not extend beyond
this life, the reason of this diversity which causes, for exam
ple, these to plunge into luxury and debauchery, and those to
prefer temperance to pleasure, would arise only from the fact
that they placed their happiness in these different things.
Th. [Jt arises thence even now, although they all have or
should have before their eyes this common object of the
future life. It is true that the consideration of true happi-
208 LEIBNITZ'S CRITIQUE OF LOCKE [UK. n
ness, even in this life, should suffice to make those who dis
card it prefer virtue to pleasure ; although the obligation
would not then be so strong or so decisive. It is also true
that men's tastes are different, and it is said that we should
not dispute about tastes. But as these are only confused per
ceptions, we should hold fast to them only in the case of ob
jects found to be indifferent and incapable of harm ; otherwise,
if one had a relish for poisons which would kill him or render
him miserable, it would be ridiculous to say that his taste
should not be called in question.]
§ 55. Ph. If there is nothing to hope for beyond the grave,
the inference is certainly very just : let us eat and drink, let
us enjoy all that gives us pleasure, for to-morrow ice die.
Th, [There is something to be said, in my opinion, regard
ing this inference. Aristotle and the Stoics and many other
ancient philosophers held another view, and I believe, indeed,
that they were right. If there were nothing beyond this life,
the peace of the soul and health of the body would not cease
to be preferable to the pleasures which would be contrary
thereto. And it is no reason whatever for neglecting a good
because it will not endure forever. But I admit that there
are cases where there would be no means of demonstrating
that the most virtuous course would be the most useful. It is
then the thought of God and of immortality only which ren
ders the obligations of virtue and justice absolutely indispen
sable.]
§ 58. Ph. It seems to me that the present judgment we
make of good and evil is always right. And as for present
happiness or misery, when reflection goes no farther, and all
consequences are wholly put aside, man never chooses amiss.
Th. [That is to say, if everything were limited to the pres
ent moment, it would not be right to refuse the pleasure which
presents itself. In fact, I remarked above that all pleasure is a
feeling of perfection. But there are certain perfections which
bring with them greater imperfections. If some one devoted
himself during his entire life to throwing peas against pins, in
order to learn not to fail to make them pierce them, after the
example of him to whom Alexander the Great caused to be
given as a recompense a bushel of peas, this man would attain
a certain perfection, but very slight and unworthy of being
cir. xxi] ON HUMAN UNDERSTANDING 209
compared with so many other very necessary perfections
which he would have neglected. Thus the perfection which
is found in certain present pleasures should yield especially
to the regard for the perfections which are necessary ; in ordev
that we be not plunged into misery, which is the state in
which we go from imperfection to imperfection, from pain to
pain. But if there be only the present, it would be necessary
to be contented with the perfection which is present, i.e. with
present pleasure.]
§ (Y2. Ph. No one would voluntarily render his condition
unhappy unless he were led by false judgments. I do not
speak of mistakes which are the result of invincible error,
and which scarcely deserve the name of false judgment, but
of that false judgment which every man must confess in
himself to be such. § Go. In the first place, then, the soul
is mistaken when we compare present pleasure or pain with
one to come which we measure by the different distance at
which they are found with respect to us : like a spendthrift
heir who for the present possession of a little something
would renounce a large heritage, which could not fail him.
Every one should recognize this false judgment, for the future
will become present, and will then have the same advantage
of nearness. If at the moment the man takes the glass in
his hand, the pleasure of drinking were accompanied with the
headache and pains in the stomach, which will follow in a
few hours, he would not in the least wish to taste the wine.
If a little difference in time causes so much illusion, with
much stronger reason a greater distance will produce the
same effect.
Th. There is some congruity here between the distance
of places and that of times. But there is also this difference,
that visible objects diminish their action upon the sight
very nearly in proportion to their distance, and it is not
at all the same as regards the future objects which act upon
the imagination and the mind. A^isible rays are straight
lines proportionally distant, but there are curved lines which
after some distance appear to fall into the straight line
and are no longer sensibly divergent: thus are made the
asymptotes, whose apparent interval diverges from the straight
lines, although in the truth of things they abide eternally
210 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
separate. We find indeed that at last the appearance of ob
jects does not diminish in proportion to the increase of the
distance, for the appearance soon l disappears entirely al
though the distance be not infinite. Thus a short distance of
time robs us entirely of the future, as if the object had en
tirely disappeared. There often remains only the name in
the mind and that kind of thoughts of which I have already
spoken, which are surd, and incapable of making an impres
sion, unless you have attended to them methodically and
habitually.]
Ph. I do not speak here of that kind of false judgment
by which what is absent is not only diminished but suddenly
annihilated in men's minds, when they enjoy all they can
obtain for the present, and then conclude that no evil will
happen to them.
TJt. [It is another kind of false judgment when the expec
tation of good or evil to come is annihilated, because the
result drawn from the present is denied or made doubtful1,
but beyond that, the error which annihilates the thought of
the future is the same thing as this false judgment of which
I have already spoken, which arises from a too feeble repre
sentation of the future, which is considered only a little
or not at all. For the rest, we might perhaps distinguish
here between bad taste and false judgment, for often we
do not even question whether the future good should be pre
ferred, and act only upon impression without presuming to
come to the examination. But when we think, one of two things
happens, either we do not continue sufficiently our thought,
and we pass on without pressing the question which has
been touched ; or we pursue the examination and form a
conclusion. And sometimes in each case there remains greater
or less self-condemnation : sometimes also there is no formido
opi-ositi or scrupulousness at all, whether the mind turns aside
at once, or is deceived by its prejudices.]
§ G4.2 Ph. The limited capacity of our mind is the cause
of the false judgments we make in comparing good and evil.
We cannot well enjoy two pleasures at once, and still less can
1 Gerhardt reads after " entierement," " bientost," which Erdmann and
Jacques omit. — TR.
2 Gerhardt. So also Locke, Philos. Works, Vol. 1, p. 402 (Bohn ed.). Erd
mann has § 25) : Jacques, § 59. — TR.
CH. xxi] ON HUMAN UNDERSTANDING 211
we enjoy any pleasure in the time that we are beset by pain.
A little bitterness mixed in the cup prevents us from tasting
its sweetness. The evil we feel is always the worst; we cry :
Ah ! any other pain rather than this !
Th. [There is much variety in all this according to men's
temperaments, the force of their feelings, and the habits they
have contracted. A man who has the gout might be joyful
because a large fortune fell to him, and a man who swims in
delights, and who might live at his ease upon the earth, is
plunged into sadness because of a disgrace at court. The fact
is, joy and sadness arise from the result or from the prevalence
of pleasures or pains, when there is a mixture of them. Lean-
der scorned the inconvenience and danger of swimming over
the sea at night, urged on by the attractions of the beautiful
Hero.1 There are people who can neither drink nor eat2 nor
satisfy other appetites without much pain, on account of some
weakness or inconvenience ; and yet they satisfy these appe
tites even beyond necessity and just limits. Others are so
effeminate or so delicate that they refuse pleasures with which
any pain, disgust or any inconvenience is mingled. There
are some persons who bravely place themselves beyond pains
and pleasures present and ordinary, and act almost alone
through fear and hope. Others are so effeminate that they
complain of the least inconvenience, or run after the least sen
sible and present pleasure nearly like children. These are
the people to whom the present pain or pleasure always ap
pears the greatest ; they are like preachers or panegyrists of
little judgment, with whom, according to the proverb : The idol
of the day is always the greatest saint of paradise.3 But what
ever variety is found among men. it is always true that they
act only according to present perceptions, and when the future
impresses them, it is always by means of an image they have
of it, or by resolution and habit which they have contracted
1 Cf. Vergil, Geor;/. :?, 258; Ovid, Ikroidex, IS, 19 (17, 18, Ocul Opera, ex
recog. Rud. Merkelii, Vol. 1, p. 141 ,sv/., Lipsia> : B. G. Teulmer, 1S87) : and, for
" the final form "of " this poem of love and death," the poem of 340 hexameters
by Mnsams, the grammarian of the fifth century A.D., an extended abstract of
which is given in J. A. Symonds' MurUesof the Greek Poets, Vol. 2, chap. 22,
pp. IU,j-3()2. New York : Harper & Bros., 1880. — TR.
2 Gerhardt reads after " manger," "on qui ne sauroient satisfaire d'autres
appetits," which Erdrnann and Jacques omit. — TR.
3 The italics are mine. — TR.
LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
in following even a simple name or other arbitrary character,
without having any picture or natural sign, because it would
not be without uneasiness, and sometimes without a feeling of
chagrin, that they would oppose themselves to a strong reso
lution already made, and, above all, to a habit.]
§ 65. Ph. Men are apt enough to diminish future pleasure,
and to conclude in themselves that, when it comes to trial, it
may perhaps not correspond to the hope it gives nor to the
opinion they generally have of it; having often found by their
own experience that not only the pleasures which others have
magnified have appeared to them very insipid, but that what
has caused themselves much pleasure at one time, has offended
and displeased them at another.
Tli. [These are mainly the reasonings of voluptuaries, but
we ordinarily find that the ambitious and avaricious judge
wholly otherwise honors and wealth, although they enjoy
only moderately, and often, indeed, very little, these same
goods when they possess them, being always occupied in going
farther. I find it a beautiful invention of nature's architect
to have rendered men so sensible to what appeals so little to
their senses ; and if they could not become ambitious or avari
cious, it would be difficult in the present state of human nature
for them to be able to become virtuous and reasonable enough
to labor for their perfection in the face of the present pleas
ures which turn them aside from it.
§ 66. Ph. As to things good or bad in their consequences
and by their aptness to procure us good or evil, we judge
them in different ways ; either when we judge them incapable
of really doing us as much evil as in fact they do, or when
we judge that while the consequence is important it is not so
certain that it may not happen otherwise, or at least that it
may not be avoided by some means, as by industry, address,
change of conduct, repentance.
Th. It seems to me that if by the importance of the conse
quence we understand that of the consequent, i.e. the great
ness of the good or evil that may follow, we must fall into the
preceding kind of false judgment, in which future good or
evil is poorly represented. Thus there remains only the sec
ond kind of false judgment, of which we shall presently treat,
namely, that in which the consequence is doubtful.]
CH. xxi] ON HUMAN UNDERSTANDING 213
Ph. It would be easy to show in detail that the subterfuges
which I have just alluded to are so many unreasonable judg
ments ; but I shall content myself with remarking in general
that it is acting directly contrary to reason to hazard a greater
good for a less [or to expose1 ourselves to misery in order to
acquire a little good or to avoid a little evil], and that, too,
upon uncertain conjectures and before we have entered upon a
due examination.
Tli. [As these are two heterogeneous considerations (i.e.
considerations which cannot be compared with each other),
that of the greatness of the consequence and that of the
greatness of the consequent, moralists in desiring to compare
them are much perplexed, as appears in the case of those who
have treated of probability. The truth is that here as in
other estimates disparate and heterogeneous and, so to speak,
of more than one dimension, the greatness of that which is
discussed is in reason composed of both estimates, and is li'ke a
rectangle, in which there are two considerations, viz. that of
length and that of breadth ; and, as for the greatness of the
consequence and the degrees of probability, we still lack that
part of Logic which is to estimate them,2 and the most of the
1 Gerhardt reads : " exposer " ; Erdmann and Jacques : " opposer." — TR.
2 I.e. the Calculus of Probabilities, the founder of which was Pascal,
162.3-1662, who developed the mathematical theory of probability in his cor
respondence with Fermat, 1601-1665, concerning certain questions on the
equitable division of the stakes in games of chance proposed to Pascal by the
Chevalier de Mere. Cf. I. Todlmnter, History of the Theory of Probability
from the time of Pascal to that of Laplace, pp. 7-21, 8vo. Cambridge and
London, 1865. Contributions were made to the theory by many of the dis
tinguished mathematicians of the period and after, including James Bernoulli,
1654-1705; Huygens (vid. ante, p. 150, note 3) ; Demoivre, 1667-1754, in his
Doctrine of chances, or method of calculating the probabilities of events at
plail, .">d ed., London, 1756; Laplace, 1749-1827, in his Theorie analijtiqne des
probabilities (Vol. 7 of his CEurres completes, pnbliees sons les auspices de
I' Academic des Sciences, seven vols.. 4to Paris, 1878-1886), since which
but little advance has been made in the theory; and Poisson, 1781-1840, in
his RechercJies sn.r la probabilite des jut/ements oi matieres criminelles, etc.,
4to Paris, 1837. Leibnitz became acquainted with Pascal's labors during
his residence in Paris, 1672-167(5: cf. Guhrauer. L'ihnitz. Leben, 1, 113 sq.
He recognized the immense importance of tbis new " part of Logic," and
thought to substitute it for the old and crude casuistry which had so long
prevailed. In tbe letter to Bourguet, March 22, 1714, Gerhardt, 3, 570: Erd
mann, 723, Leibnitz glances briefly at the historical rise of tbe calculus of
probabilities. For the philosophical side of the question, cf. J. S. Mill, Lof/ic,
Bk. III., chaps 18, 23, pp. 379 sq., 416 sq., 8th ed., Harper and Bros., New
214 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
casuists who have written on probability have not even under
stood its nature, founding it with Aristotle,1 upon authority,
instead of founding it as they ought upon likelihood (vraisem-
blance), authority being only one of the reasons which pro
duce likelihood.]
§ 67. Ph. Here are some of the ordinary causes of this
false judgment. First, ignorance, second, inattention., when a
man does not reflect upon that of which he is aware. This
is an affected and present ignorance which misleads the judg
ment as well as the will.
Th. [It is always present, but not always affected ; for we
do not always take it into our heads to think, when it is
necessary, of what we know and the memory of which we
should recall if we were master of it. Affected ignorance is
always mixed with some attention at the time it is affected ; in
the future, it is true, it may ordinarily include somewhat of in
attention. The art of thinking in time of need of what we know
would be one of the most important if it were found ; but I
do not see that men up to the present time have even thought
of forming the elements of it, for the art of memory - of
which so many authors have written is wholly another thing.]
Ph. If then they bring together in confusion and hastily
the reasons from one side and allow through neglect several
sums which ought to enter into the reckoning to escape, this
York, 1881; F. H. Bradley, The Principles of Lor/ic, Bk. I., chap. 7, §§ 32
sq., pp. 201 6'</., Kegan Paul, Trench and Co., London, 1883; J. Venn, The
Lo<jic of Chance, 3d ed., Maemillan and Co., London, 1888; W. S. Jevons, The
Principles of Science, 3d ed., Maemillan and Co., London, 1889. — TR.
1 For Aristotle's definition of probability, cf. Anal. Prior., II., 27, 70a3:
"The probable is a generally admitted proposition. For what is known for
the most part as thus happening or not happening, or being or not being, this
is probable "; cf. also Wallace, Outline*, § 21, who quotes the Greek of the
passage. Rhet.l., 2, 1357a34: "For the probable is that which for the most
part happens." Aristotle accordingly rests much more upon experience
than upon authority, and Leibnitz has not given his definition accurately.
" The probable conclusion,1" says Schaarschmidt, is for Aristotle, "an incom
plete induction, whose problematic character he well understood, but did not
determine more closely. Later Greek philosophers of a sceptical creed began
to speak of grades of probability, but the moderns have been the first to
fall upon the fruitful thoughts of a mathematical estimate of probability."
-TR.
2 Mnemonics, the invention of which was ascribed to the poet Simonides,
of Ceos, 5f>(>-469 B.C., perhaps because he was famous for the strength of his
own memory. Cf. Cicero, l)e Oratore, Bk. II., chap. 82. — TR.
CH. xxi] ON HUMAN UNDERSTANDING
haste produces no less false judgments than if it were perfect
ignorance.
Tli. [In reality many things must be taken into account, as
should be the case, when the balance of reasons is discussed ;
and the process is almost like that in the account-books of
merchants. For no sum must be neglected, each must be
properly estimated by itself, they must be properly arranged,
and finally an exact collection must be made of them. But
we neglect many weighty points either by its not occurring to
us to think of them or by passing lightly over them ; and we
do not give each its proper value, like the book-keeper, who
.was careful properly to calculate the columns of each page,
but who calculated very badly the particular sums of each
line or posting, before putting them in the columns ; this
causes the examiners to be deceived, who look principally at
what is in the columns. Finally, after having carefully noted
all, they may be deceived in the collection of the sums of the
columns and even of the final collection, in which is the sum
of the sums. Thus we should still need the art of thinking
and that of estimating probabilities, and besides the knowl
edge of the value of goods and evils in order properly to
employ the art of consequences ; and furthermore, attention
and patience would be necessary after all that, in order to
push to the conclusion. Finally, a firm and constant resolu
tion to execute the conclusion arrived at is necessary ; and
address, method, particular laws, and habits entirely formed
in order to maintain the course in the future, when the con
siderations, which have caused it to be taken, are no longer
present to the mind. It is true, thank God, that in what is of
the greatest importance and which concerns the summam
rerum, happiness and misery, there is no need of so much
knowledge, aid, and address, as it would be necessary to have
in order properly to judge in a council of state or of war, in
a tribunal of justice, in a medical consultation, in some theo
logical or historical controversy, or in some point of mathe
matics or mechanics ; but as a recompense more firmness and
habit is necessary, in what concerns this great point of fe
licity and virtue, in order always to adopt good resolutions
and to follow them. In a word, for true happiness less
knowledge suffices with more good will ; so that the greatest
LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
idiot may attain it as easily as the most learned and most skil
ful.]
Ph. You see then that without liberty the understanding
would be of no use, and that liberty without understanding
would signify nothing. If a man could see what may do him
good or evil without being able to move a step in advance
towards the one or in removal from the other, would lie be
the better for the sight ? He would be indeed more miserable
for this reason, for he would uselessly pine after the good and
would fear the evil, that he sees is inevitable ; and he who is
at liberty to run here and there in the midst of perfect dark
ness, in what respect is he better than if he were tossed about
at the pleasure of the wind ?
Th. [His caprice would be a little better satisfied, but lie
would be in no better condition to meet good or to shun evil.]
§ 68. Ph. Another source of false judgment. Content with
the first pleasure which comes to hand or which custom has
rendered agreeable, we do not look farther. This then is
also an occasion for men to judge wrongly when they do not
regard as essential to their happiness that which really is so.
Th. [It seems to me that this false judgment is comprised
under the preceding kind where one is mistaken as to the
consequences.]
§ (>9. Ph. The inquiry remains whether a man has the
power to change the pleasure or displeasure which accom
panies any particular action. In many cases he can. Men
may, and ought to, correct their palates and make them acquire
a taste. They can change also the taste of the soul. A due
consideration, practice, application, custom will bring about
this result. Thus it is that men accustom themselves to
tobacco, which usage or custom at last makes them find agree
able. It is the same as regards virtue. Habits have powerful
charms and we cannot depart from them without uneasiness.
You will, perhaps, regard it as a paradox that men can make
things or actions more or less agreeable to themselves, so much
do they neglect this duty.
Th. [I have already made this statement above, § 37.
towards the end, and § 47, also towards the end. We can
make ourselves will anything and form our taste.]
§ 70. Ph. Morality, established upon true foundations, can
en. xxi] OX HUMAN UNDERSTANDING 217
only determine to virtue : it suffices that infinite happiness
and misery after this life are possible. We must admit that
a good life, joined with the expectation of possible eternal
felicity, is preferable to a bad life, accompanied by the fear of
terrible misery, or, at least, of the terrible and uncertain hope
of annihilation. All this is in. the highest degree self-evident, •
although virtuous men should have only evil to endure in this
world, and the wicked should taste therein perpetual pleas
ure, which is ordinarily quite otherwise. For rightly consid
ering all things, I believe they have the worst part even in
this life.
T/L [Thus were there no life beyond the grave an epicurean
life would not be the most reasonable. And I rejoice, sir, that
you rectify what you said to the contrary above, § 55.]
Ph. Who could be so foolish, as to resolve (if he had his
senses) to expose himself to a possible danger of being infin
itely unhappy so that he has nothing to gain therefrom for
himself but pure annihilation ; instead of putting himself in
the condition of the good man who has nothing to fear but
annihilation, and who has eternal felicity to hope for ? I
have forborne to speak of the certainty or probability of the
future state, because I have no other design in this place than
to show the false judgment of which each should acknowledge
himself guilty on his own principles.
Th. [The wicked are very prone to believe that the other
life is impossible. But they have no reason for their belief
other than that which compels them to limit themselves to
what they learn by their senses, and that no one to their
knowledge has come back from the other world. There was a
time when upon the same principle we could reject the anti
podes, when we were unwilling to unite mathematics and the
popular notions ; and we could do so with as much reason as
we can now have in rejecting the other life, when we are
unwilling to unite true metaphysics and the notions of the
imagination. For there are three degrees of notions or ideas,
viz. : popular, mathematical, metaphysical. The first do not
suffice to make us believe in the antipodes ; the first and the
second do not yet suffice to make us believe in the other
world. It is true they furnish already favorable conjectures ;
but if the second established certainly the antipodes before
LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
the experience we now have of it (I speak not of the inhabi
tants, but of the place at least which the knowledge of the
roundness of the 'earth gave them among geographers and
astronomers), the last give no less certitude of another life
from this time, and before you have gone to see.]
§ 72. Ph. Let us now return to power which is properly
the subject of this chapter, liberty being only one form of it,
but the most important. In order to have more distinct ideas
of power, it will be neither beside the purpose nor useless to
obtain a more exact knowledge of what is called action. I
said at the beginning of our discourse on power that there
are two kinds of actions, of which we have some idea, viz. :
motion and thought.1
Th. [I thought you could avail yourself of a more general
term than that of thought, viz. : that of perception, attributing
thought only to minds, while perception belongs to all the
entelechies. But I do not wish, however, to contest with any
one the liberty to take the term thought in the same general
way. And for myself indeed I shall perhaps do so some time
without being aware of it.]
Ph. Xow, although we give to those two things the name of
action, we shall find however that it does not always suit them
perfectly, and that there are some examples which we shall
recognize rather as passions. For in these examples sub
stance, in which we find movement or thought, receives purely
from without the impression through which action is com
municated to it, and acts only by the sole capacity it has
of receiving this impression, which is only a passive power.
Sometimes substance or the agent puts itself in action by its
own power, and it is there properly an active power.
Th. I have already said that, taking action in metaphysical
strictness as that which takes place in substance spontaneously
and from its own depths, that alone is, properly speaking, a
substance which is active,2 for all arises for it from itself after
God ; it being impossible for one created substance to have
1 Locke has: "thinking," Philos. Works, Vol. 1, p. 413 (Bonn's ed.).— TR.
2 Cf. De ipsa nature., etc., 1(598, § 9 ad fin.; Gerhardt, 4, 509; Krdmann,
157; Jacques, 1, 401 (in French); J. H. v. Kirchmaim, Die klcin. philos.
U'icht. Schrift. v. G. W. Leibniz (Philos. BiWiotliek, Bd. 81), p. 121 (in Ger
man), Erick Koschny, Leipzig, 1879 ; also Kuno Fischer, Gesrh. d. ncucrn Philos.,
Vol. 2 (G. W. Leibniz), p. 334, 3d ed., Heidelberg: C. Winter, 1889. — TR.
en. xxi] ON HUMAN UNDERSTANDING 219
influence upon another. But taking action as an exercise of
perception and passion as its contrary, there is action in true
substance only when their perception (for I grant it to all) is
developed and becomes more distinct, as there is passion only
when it becomes more confused ; so that in substances capable
of pleasure and of pain, all action is a step towards pleasure
and all passion a step towards pain. As for motion, it is
only a real phenomenon, because matter and mass to which
motion belongs is not properly speaking a substance. But
there is an image of action in motion as there is an image of
substance in mass ; and in this respect we can say that the
body acts (a git) when there is spontaneity in its change and
that it is passice (patit) when it is urged on or hindered by
another ; as in the veritable action or passion of a veritable
substance we may take as its action, and attribute to itself,
the change by which it tends to its perfection. And in the
same manner we can take as passion and attribute to a
foreign cause the change by which the contrary happens to it ;
although this cause is not immediate, because, in the first case,
the substance itself, and in the second the foreign things serve
to explain this change in an intelligible way. I allow bodies
only an image of substance and action, because that which is
composed of parts cannot pass, to speak accurately, as one
substance, any more than a flock; but we can say that there
is therein something substantial, of which the unity, that
which makes it as it were one being, comes from thought.]
Ph. I have thought that the power to receive ideas or
thoughts by the operation of some foreign substance was
called power of thought, although at bottom it is only a pas
sive power or a simple capacity making abstraction from the
reflections and internal changes which always accompany the
received image, for the expression,1 which is in the soul is, as
it should be, that of a living mirror ; but the power which we
have of recalling absent ideas at our choice, and of comparing
together those that we think to the purpose, is truly an active
power.
Tit. [This also agrees with the notions I have just pre
sented, for there is in this a passage to a more perfect state.
1 Gerhardt and Erdmann read: " 1'expressiou " ; Jacques: " 1'impres-
sion." — TK.
LEIBNITZ'S CRITIQUE OF LOCKE [HK. n
But I should suppose that there is also action in sensations so
far as they give us more distinct perceptions and consequently
the opportunity of making remarks and so to speak of devel
oping ourselves.]
§ 73. Ph. Now I think it appears that we can reduce the
primitive and original ideas to this small number : extension,
solidity, mobility (i.e. passive power, or rather capacity of
being moved), which come to us in the mind by way of reflec
tion, and finally, existence, duration, and number, which come
to us by the two ways of sensation and reflection ; for by
these ideas we could explain, if I am not mistaken, the nature
of colors, sounds, tastes, odors, and all the other ideas we
have, if our faculties were subtile enough to perceive the dif
ferent motions of the minute bodies which produce these sen
sations.
Tli. To speak the truth, I believe that these ideas, which
you here call original and primitive, are for the most part not
wholly so, being susceptible in my view of further resolution ;
but I do not blame you at all, sir, for having limited yourself
and for not having pushed the analysis farther. Moreover,1 I
believe that if their number can be diminished by this means,
it can be increased by adding other ideas more original or as
much so. As to the question concerning their arrangement, I
should consider, following the order of the analysis, exist
ence anterior to the others, number to extension, duration to
motivity or mobility ; although this analytic order is not
ordinarily that of the occasions which make us think of them.
The senses furnish us the material for reflection and we should
not even think of thought, if we did not think of something
else, i.e. of the particular things which the senses furnish.
And I am persuaded that created souls and minds are never
without organs and never without sensations, as they cannot
reason without characters. Those who have desired to main
tain a complete separation and mode of thinking in the sepa
rated soul, inexplicable by all that we know, and separated
1 Gerhardt reads: " D'ailleurs je crois que si le nombre en pourroit estre
diminue par ce moyen, il pourroit estre augmente," etc. ; Erdmann and Jacques
read : " D'ailleurs si c'est vrai, que le nombre en pourroit etre diminue' par ce
moyen, je crois qu'il pourroit etre augumente en y ajoutant d'autres Idees
plus originales ou autant." — TR.
CH. XXH] ON HUMAN UNDERSTANDING 221
not only from our present experiences, but, what is much
more, from the general order of things, have given too much
influence to so-called strong minds, and have made the finest
and the grandest truths objects of suspicion to many people,
having indeed deprived themselves thereby of some excellent
means of proving them, which this order furnishes us.]
CHAPTER XXII
OF MIXED MODES
§ 1. Ph, Pass we on to the mixed modes. I distinguish
them from the more simple modes, which are composed only of
simple ideas of the same kind. Moreover, the mixed modes
are certain combinations of simple ideas which are not re
garded as characteristic marks of any real being, which has a
fixed existence, but as scattered and independent ideas which
the mind joins together; and they are thereby distinguished
from the complex ideas of substances.
Tli. [Properly to understand these we must recall our for
mer divisions. According to you ideas are simple or complex.
The complex are either substances, modes, or relations. Modes
are either simple (composed of simple ideas of the same kind)
or mixed. Thus, in your view, there are simple ideas, ideas
of modes, both simple and mixed, ideas of substances and
ideas of relations. We could, perhaps, divide the terms or
the objects of ideas into abstract and concrete ; the abstract
into absolute and into those which express relations; the
absolute into attributes and into modifications ; both into
simple and composite; the concrete into substances and into
substantial things, made up of or the resultants of true and
simple substances.]
§ 2. Ph. The mind is purely passive, respecting its simple
ideas, which it receives as sensation and reflection present
them to it. But it often acts by itself, .indeed, in reference
to the mixed modes, for it can combine the simple ideas in
making complex ideas without considering whether they so
exist united in nature. This is why we give to these kinds of
ideas the name of notion.
222 LEIBNITZ'S CRITIQUE OF LOCKE [UK. 11
Th. [Hut reflection which makes us think of simple ideas
is often voluntary also, and, moreover, the combinations, which
nature has not made, can produce themselves in us, as it were
in dreams and reveries by means of memory alone, without
the mind's acting more than in the simple ideas. As for the
term 'notion, many apply it to all sorts of ideas or conceptions,
to the original as well as to the derived.]
§ 4. Ph. The mark of several ideas combined in one alone
is the 'name.
Th. [That means, if they can be combined, in which respect
they are often lacking.]
Ph. The crime of killing an old man, not having a name
like parricide, is not at first regarded as a complex idea.
Th. [The reason why the murder of an old man has no name
is that, the laws not having attached thereto a particular pun
ishment, this name would be useless ; but ideas do not depend
on names. An ethical author who should invent one for the
crime and treat in a special chapter of Gerontopliony, showing
what is due to old men and how it is a barbarous act not to
spare them, would not on that account present us with a new
idea.]
§ 0. Ph. It is always true that the manners and usages
of a nation, making combinations familiar to it, cause each
language to have particular terms, which cannot always be
translated word for word. Thus ostracism among the Greeks
and prowriptio among the Romans were words which other
languages cannot express by equivalent words. Therefore,
change of customs makes also new words.
Th. [Chance also plays its part, for the French do not use
horses as much as other neighboring peoples ; but having
abandoned their old word, which corresponded to the cavalcar
of the Italians, they are forced to say by paraphrase : aller <\
cheval — to go on horse-back.]
§ 9. Ph. We acquire ideas of mixed modes by observation,
as when we see two men wrestling ; we acquire them also by
invention (or a voluntary union of simple ideas), thus, he who
invented printing had the idea of it before this art existed.
We acquire them finally by explaining terms, affecting actions
which we have never seen.
Th. [We can further acquire them while dreaming or in a
en. xxn] ON HUMAN UNDERSTANDING
state of revery without the combinations being voluntary, for
example, when we see in a dream a golden palace without
having thought of it before.]
§ 10. Ph. The simple ideas which have been most modified
are those of thought, motion, and power, whence actions are
conceived to flow; for the great business of mankind consists
in action ; all actions are thoughts or motions. The power or
aptitude to do anything which is found in man constitutes
the idea which we call habit, when this power has been
acquired by often doing the same thing; and when we can
force it to action upon each occasion that presents itself, we
call it disposition. Thus, tenderness is a disposition to friend
ship or love.
Th. [By tenderness you understand here, I presume, the
tender heart, but elsewhere you seem to me to regard tender
ness as a quality which one has, as a lover, which renders him
very sensible to the good and evil of the object loved. This it
is to which it seems to me the chart of affection is moving in
the excellent romance Cldie.1 And, as charitable persons love
their neighbor with some degree of tenderness, they are sensi
ble to the good and evil of another, and generally those who
have the tender heart have some disposition to love with ten
derness.]
Pit. Boldness is the power to do or say before others what
you wish without being put out of countenance, a self-confi
dence, which, in relation to this last part which concerns dis
course, had a particular name among the Greeks.
Th. [It would be well to seek a word for this notion, which
is here attributed to that of boldness, but which is often em
ployed wholly otherwise, as when we say Charles the Bold.
Not to be put out of countenance is a strength of mind, but
one which bad men abuse when they have become impudent;
as shame is a weakness, but excusable and even praiseworthy
in certain circumstances. As for pari'hesia,2 which you per
haps understand by the Greek word, it is still attributed to
writers who speak the truth without fear, although, then not
1 Clelie, Histoire Romainc, a romance by Mile. Scudery, 1607-1701. The
s-ene is laid early in Roman history ; the heroine is Cloelia, who escaped from
Porsena by swimming the Tiber. — Tn.
,. — TH.
224 LEIBNITZ'S CRITIQUE OF LOCKE [UK. n
speaking in the presence of people, they are not liable to be
discountenanced. ]
§ 11, Ph. As poicer is the source whence proceed all actions,
the name of cause is given to the substances in which these
powers reside, when they reduce their power to act; and they
call effects the substances produced by this means, or rather
the simple ideas (i.e. the objects of simple ideas), which, by
the exercise of power are introduced into a subject. Thus the
efficacy by which a new substance or idea (quality) is pro
duced, is called action in the subject exercising this power and
passion in the subject in which some simple idea (quality) is
altered or produced.
Th. [If poicer is taken as the source of action, it means
something more than an aptitude or facility, by which power
was explained in the preceding chapter ; for it includes, be
sides, tendency as I have already more than once remarked.
This is why in this sense I have been wont to appropriate to
it the term entelechy, which is either %)rimitive and answers to
the soul taken as an abstract thing, or derivative as it is con
ceived in conation (le couatus) and in vigor and impetuosity.
The term cause is here understood only as efficient cause; but
it is also understood as final or the motive, not to speak here
of matter and form which are also called causes in the schools.
I do not know whether we can say that the same being is
called action in the agent and passion in the patient, and is
thus found in two subjects at once like relation, and, whether
it is not better to say that there are two beings, one in the
agent, the other in the patient.]
Ph. Many words which seem to express some action signify
only the cause and the effect ; as creation and annihilation
contain no idea of action or of the manner, but simply of the
cause and the thing which is produced.
Th. [I admit that in thinking of creation, we do not con
ceive a mode of acting, capable of any detail, which cannot
indeed there be expedient; but, since we express something
besides God and the world, for we think that God is the cause
and the world the effect, or else that God has produced the
world, it is manifest that we think still of action.]1
1 Leibnitz regards the concept of creation in the sense of the origination of
substances as incapable of further explanation because we can form no idea
CH. xxni] ON HUMAN UNDERSTANDING 225
CHAPTER XXITI
OF OUR COMPLEX IDEAS OF SUBSTANCES
§ 1. Ph. The mind notices that a certain number of simple
ideas constantly go together, which, presumed to belong to one
thing only, are called by one name when thus united in one
subject. Whence it comes that, although this is in truth a
mass of many ideas joined together, we are afterwards led by
inadvertence to speak of them as a single, simple idea.
Th. [I see nothing in the accepted expressions which de
serves to be taxed with inadvertence ; and although we recog
nize only one subject and one idea, we do not recognize only
one simple idea.]
Ph. Not being able to imagine how these simple ideas can
subsist by themselves, we are accustomed to assume something
which sustains them (substratum}, in which they subsist or
whence they result, to which for this effect we give the name
of substance.^
Th.1 [I believe that there is reason in thus thinking, and
we have only to accustom ourselves to it or to assume it, since,
at first, we conceive several predicates in one and the same
subject, and these metaphorical words, support (soutien) or sub
stratum mean only this ; so that I do not see why it should
cause any difficulty. On the contrary, it is rather the concretum,
as wise, warm, shining, which arises in our mind, than the
abstractions or qualities (for these and not the ideas are in
the substantial object), as knowledge, heat, light, etc., which
are much 'more difficult to comprehend. We may even doubt
whether these accidents are veritable existences, as in fact
they are very often only relations. We know also that it is
these abstractions which cause the greatest difficulties to
spring up when we wish to examine them minutely, as those
of the process. For some other expressions concerning it, cf. La Monodo-
loffie, § 47, Gerhardt, 6, 614 ; Erdmann, 708, b. ; Letter to Bayle, Gerhardt, 3,
58; Erdmann, 191. Gerhardt, 3. 01. and note, says the original is without
date; Erdmann gives it 1702. TV', also Dillmann, *Eine neue Darstg. d. Leib
niz. Monadenlehre, p. 451 sq. — TR.
1 Erdmann has " Ph.," a typographical error. — TR.
Q
LKIIJNITZ'S CRITIQUE OF LOCKE
know who are familiar with the subtilties of the scholastics,
the most intricate of which falls at once if we will banish
abstract existence and resolve to speak ordinarily only by
concretes and admit no other terms in scientific demonstra
tions but those which represent substantial subjects. Thus it
is nodum quaerere in scirpo,1 if I may so speak, and reversing
things to take the qualities or other abstract terms as the
easier and the concrete as something very difficult.]
§ 2. Ph. We have no other notion at all of pure substance
in general, than of an indescribable subject, which is to us
altogether unknown and which is supposed to be the support
of qualities. We speak like children to one who has no
sooner asked them what a certain thing unknown to them is,
than they make this reply very satisfactory to their taste that
it is something, but, which employed in this way, means that
they do not know what it is.
Th. [In distinguishing two things in substance, the attri
butes or predicates, and the common subject of these predi
cates, it is no wonder that we can conceive nothing particular
in this subject. It must be so, indeed, since we have already
separated from it all the attributes in which we could conceive
any detail. Thus to demand something more in this pure subject
in general than what is necessary in order to conceive that it
is the same thing (for example, which understands and wills,
which imagines and reasons), is to demand the impossible,
and to act contrary to our own supposition, which has been
made in making abstraction and conceiving separately the
subject and its qualities or accidents. We could apply the
same pretended difficulty to the notion of being and to all that
is clearer and more primitive ; for we could demand of the
philosophers what they conceive when conceiving pure being
in general ; for all detail being excluded by that means there
will also be little to say, when we are asked what is pure sub
stance in general. Thus I believe that the philosophers do
not deserve to be laughed at, as is here done, in comparing
them with an Indian philosopher, who, being asked upon what
the earth rested, replied, upon a great elephant; and then
when asked what sustained the elephant, replied, a great tor-
1 To seek a knot in a bulrush, to find a difficulty when there is none. C/.
Plaut. Men. 2, 1, 22 ; T'-r. And. ."». 4. •'«. — TH.
en. xxmj OX HUMAN UNDERSTANDING 227
toise; and, at last, when pressed to say upon what the tortoise
rested, was compelled to say something. I know not what. But
this consideration of substance,1 entirely slender as it appears,
is not so empty and sterile as you think. It gives rise to
many consequences of greatest importance in philosophy, and
which are capable of giving it a new aspect.]
§ 4. Ph. We have no clear idea of substance in general, and
§ 5, we have as clear an idea of mind as of body ; for the
idea of corporeal substance in matter is as far from our con
ceptions as that of spiritual substance. It is almost as the
promoter said to this young doctor of law, who cried to him
in the solemnity, to say utnusqtte : You are right, sir, for you
know as much in the one case as the other.
Tit. [As for myself, I believe that this opinion of our igno
rance arises from that which demands a kind of knowledge of
which the object does not admit. The true mark of a clear
and distinct notion of an object is the means we have of
knowing therein many truths by a priori - proofs, as I have
shown in a discourse on truths and ideas/'' published in the
"' Actes de Leipzig " of the year 1684.
§ 12. Ph. If our senses were sufficiently penetrating, the
sensible qualities, for example, the yellow color of gold, would
disappear, and instead of that we should see a certain admir
able contexture of parts. This appears evident by means of
microscopes. This present knowledge is suitable to the state
in which we find ourselves. A perfect knowledge of things
1 In Leibnitz's philosophy substance is a unitary, individual, spontane
ously active being, as opposed to the " empty and sterile " conception of Aris
totelian scholasticism; cf. ante, p. 15-1 and note. Locke's criticism concerns
the scholastic conception only. — TR.
2 Cf. New Essays, Bk. IV., chap. 17, § 1, Tli.; Theodicee, I., § 44, Gerhardt,
6, 127; Erdmann, 515, b. For a brief critical history of the concepts of the
<? priori and the a posteriori, cf. Rudolph Eucken, The fundamental Concepts
of Modern Philosophic Thought, pp. 81-1)1, D. Appleton and Co., New York,
1880 ; and for Leibnitz's use of the terms, op. eit., p. 82, with the note contain
ing references to the places where a priori occurs in Erdmann 's and Foucher
de Careil's editions of Ins works. — TR.
3 Meditat tones de Cof/nitione, Veritate et Ideis, in the " Acta Eruditorum,"
Nov., 1684. Gerhardt, 4, 422 sq. ; Erdmann, 7!) .sv/. The passage referred to
is found in Gerhardt, 425 ; Erdmann, 80 b.; translation, Duncan, Philos. Works
of Leibnitz, 30. The piece has been translated into German, with notes, by
j. H. v. Kirchmann in his Philos. ftiblinthek, Bd. 81, /He klcin. philos. wicht.
Schriften r. G. W. Leibniz ; Bd. 82, Erldvtervnyen. — TR.
228 LEIBNITZ'S CRITIQUE OF LOCKE [UK. n
which surround us, is, perhaps, beyond the capacity of every
finite being. Our faculties suffice to make us know the Crea
tor, and to instruct us as to our duties. Should our senses
become more acute, such change would be incompatible with
our nature.
Th. [All that is true ; and I have said something to the
same effect above. But the color yellow does not cease to
be a reality like the rainbow, and we are apparently destined
to a state far beyond the present, and can even go on to the
infinite, for there are no elements in the corporeal nature. If
there were atoms, as the author appeared to believe in another
place, perfect knowledge of the body could not be beyond
every finite being. For the rest, if some colors or qualities
should disappear from our eyes better armed or become more
penetrating, others would apparently spring into being, and
it would require a new growth of our perspicacity to make
these also disappear, and this could go on to infinity, as the
actual division of matter effectively proceeds.]
§ 13. Ph. I do not know but that one of the great advan
tages which some spirits have over us consists in the fact that
they can assume to themselves organs of sensation which are
precisely suited to their present design.
Th. [We do this indeed in making for ourselves micro
scopes ; but other creatures can go much farther. And. if we
could transform our eyes themselves, which we do effectively
to some extent According as we wish to see near at hand or at
a distance, we should be obliged to have something1 belonging
more exclusively to us than they in order to shape them by
its means, for it is necessary, at least, that all be done mechan
ically, because the mind cannot operate immediately upon the
body. For the rest, I am also of the opinion that genii per
ceive things in a manner which is somewhat related to ours,
even if they should have the agreeable advantage which the
imaginative Cvmno2 attributes to some animated natures in
1 I.e. the soul to make use of the capacity of the eyes for accommodation.
— TR.
2 Cyrano de Bergerac, c. 1020 — 1655, in his philosophical romance, Histoire
comique des etats et empires du soldi. He was author also of the Histoire
comique des etats et empires de la lune, or, as the title is sometimes given,
Voyage dans la lane. — TR.
en. xxin] ON HUMAN UNDERSTANDING 229
the sun, composed of an infinite number of little winged crea
tures, which, by transporting themselves according to the
command of the ruling soul, form all kinds of bodies. There
is nothing so marvellous that the mechanism of nature cannot
produce it ; and I believe that the learned fathers of the
Church were right in attributing bodies to the angels.1]
§ 15. Ph. The ideas of thinking and of moving a body,
which we find in that of the mind, can be conceived as clearly
and distinctly as those of extension, solidity, and mobility,
which we find in matter.
Th. [As regards the idea of thought I agree. But I am
not of this opinion as regards the idea of moving bodies, for,
according to my system of Pre-established Harmony, bodies
are so made that being once put in motion, they continue
therein, according as the actions of the mind require. This
hypothesis is intelligible ; the other is not.]
Ph. Each act of sensation gives us an equal view of things
corporeal and spiritual ; for while sight and hearing give me
the knowledge that there is some corporeal being without me,
I know in a way still more certain that there is within me a
spiritual being which sees and hears.
Th. [It is very well said and very true that the existence
of the spirit is more certain than that of sensible objects.2]
§ 19. Ph. Spirits as well as bodies can operate only where
they are and in different times and places ; thus I can only
attribute change of place to all finite spirits.
Th. [I believe that is reasonable, place being only an order
of coexistences.]
Ph. It is only necessary to reflect upon the separation of
the soul and the body by death to be convinced of the move
ment of the soul.
Th. [The soul might cease to operate in this visible body ;
and if it could cease thinking all at once, as the author has
maintained above, it might be separated from the body with
out being united to another ; thus its separation would be
without movement. But for myself, I believe that it thinks
1 Cf. Letters to Des Bosses, Sept. 20, Oct. 4, 1706, Gerhardt, 2, 316, 319;
Erdraann, 439. Also Descartes' letters, passim. — TR.
2 Cf. Descartes, Meditations, especially II. and VI. Veitch's translation,
8th ed., pp. 104 sq., 151 sq. — TR.
2:-JO LEIBNITZ'S CRITIQUE OF LOCKE [»K. n
and feels always, that it is always united to some body, and,
indeed, that it never leaves entirely and all at once the body
to which it is united.]
§ 21. Ph. If anyone says that spirits are not in loco sed in
ali(jno -nbi I do not suppose that now we would rely much
upon tliis method of speaking. But if anyone thinks that
it can receive a reasonable sense, 1 pray him to express it in
language generally intelligible, and to draw therefrom after
wards a* reason showing that spirits are not capable of motion.
Tli. [The schools have three kinds of Ubeity, or modes of
existing somewhere. The first is called circumscriptive, which
they attribute to bodies in space which are there punctatim, in
such wise that they are measures according to which we can
assign the points of the thing placed corresponding to the
points of space. The second is the definitive, when we can
define, i.e. determine, that the situated thing is in such a space,
without being able to assign the precise points or the peculiar
places exclusive of what is there. Thus it has been con
sidered that the soul is in the body, not supposing it possible
to assign a precise point at which the soul or some portion of
the soul is, without its being also at some other point. More
over, many learned men have thus viewed the matter. It is
true that Descartes desired to place narrower limits to the
soul by locating it properly in the pineal gland.1 Neverthe
less he did not dare to say that it is exclusively at a certain
point in tliis gland ; and this not being so he gains nothing,
and it is in this respect precisely as if he gave it the entire
body as its prison or place. I believe that nearly the same
statement as that made regarding souls, must be made in
respect to the angels, whom the great doctor, a native of
Aquino, believed to be in a place only by operation - which in
my view is not immediate and reduces itself to pre-established
harmony. The third ubeity is the repletive, which is attrib
uted to God, who fills all the universe in a still more eminent
degree than the disembodied spirits, for he works immediately
1 Cf. Descartes, Dioptrica, IV., 1 *(?.,• Pctssiones Animse, I., )>1 sq.: also
Pnn. Philox., IV,, 18!), 1%, 197, although here the point of contact in the
brain of the soul and body is not designated by name. — TR.
2 Cf. Thomas Aquinas, 1225 or 1227-1274, Summa Theoloyica, Pt. I. Quest.
52, Article, 2; also Quest. 53. — TR.
en. xxni] ON HUMAN UNDERSTANDING
upon all creatures by continually producing them, while finite
spirits cannot exercise any immediate influence or operation.
L do not know whether this doctrine of the schools deserves
to be ridiculed, as it seems some try to do. "But we can
always attribute a kind of movement to souls at least in rela
tion to the bodies with which they are united, or in relation
to their mode of perception.]
§ 23. Ph. If any one says he knows not how he thinks, I
reply that he knows no more how the solid particles of the
body are united to make an extended whole.
Tli. [It is difficult enough to explain cohesion ; but this
cohesion of parts does not appear necessary to make an
extended whole, since we can say tfrat matter perfectly subtile
and fluid constitutes an extension, without the particles being
united the one to the other. But, to speak the truth, I
believe that perfect fluidity belongs only to the primary
matter,1 i.e. matter in the abstract, and, as an original quality,
just as repose ; but not to secondary matter, such as is
actually found, invested with its derivative qualities; for, I
believe that there is no mass, which is of the utmost subtil-
ity ; and that there is more or less connection everywhere,
which arises from movements so far as they are conspirant
and would be disturbed by separation, which cannot take
place without some violence and resistance. For the rest, the
nature of perception and thus of thought furnishes a notion
of the most original conditions. I believe, further, that the
doctrine of substantial unities or monads will throw much
light upon it.]
Ph. As for cohesion, many explain it by means of the sur
faces by which two bodies touch, which an ambient fluid- (for
example, the air) presses one against another. It is very
true that the pressure § 24 of an ambient fluid can hinder the
avulsion of two polished surfaces from one another in a line
perpendicular to them ; but it cannot hinder them from separat
ing by a movement parallel to these surfaces. This is why,
if there were no other cause of the cohesion of bodies, it
would be easy to separate all their parts, by making them thus
1 Cf. ante, p. 131 and note. — TR.
2 Locke's term, Philos. Works, Vol. 1, p. 438, § 24 (Bohn's ed.). — TR.
232 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
slide laterally, taking therefor any plane you wish which
intersects any mass of matter.
Th. [Yes, no doubt if all the smooth particles applied to
each other were in one and the same plane or in parallel
planes ; but that not being so nor capable of so being, it is
manifest that in trying to make the one slide, you will act
altogether differently upon an infinite number of others, whose
plane will make an angle with the first ; for you must know
that it is difficult to separate two congruent surfaces, not only
when the direction of the movement of separation is perpen
dicular, but further when it is oblique to the surfaces. Thus
it may be conceived that there are leaves applied to one
another in every direction in the polyhedral bodies that nature
forms in ores and elsewhere. But I admit that the pressure
of the ambient fluid upon smooth surfaces applied to each
other does not suffice to explain the basis of all cohesion, for
it is tacitly assumed that the tables applied the one against
the other already have cohesion.]
§ 27. Ph. I have always supposed that the . extension of a
body was something else than the cohesion of solid particles.
Th. [That does not appear to me to agree with your own
preceding explanations. It seems to me that a body in which
there are internal movements or whose particles are in the act
of detaching themselves one from another (as I believe hap
pens always) cannot be extended. Thus the notion of exten
sion appears to me wholly different from that of cohesion.]
§ 28. Ph. Another idea we have of body is the power of
communicating motion by impulse; and another we have of the
soul is the power of producing motion by thought. Experience
clearly furnishes us each day these two ideas ; but if we wish
to investigate further how this is done, we find ourselves
equally in the dark. For, as regards the communication of
motion, wherein one body loses as much motion as another
receives, which is the most ordinary case, we conceive there
nothing else than a motion which passes from one body into
another ; which is, I think, as obscure and as inconceivable
as the manner in which our mind moves or stops our bodies by
thought. It is still more difficult to explain the increase of
motion by means of impulse, which is observed or believed to
happen in certain cases.
CH. xxin] ON HUMAN UNDERSTANDING 233
Th. [I am not astonished that you find insurmountable dif
ficulties where you seem to assume a thing so inconceivable
as the passage of an accident from one subject to another ;
but I see nothing which compels us to an assumption which is
no less strange than that of the scholastics of accidents with
out a subject, which they have taken care however to attribute
only to the miraculous action of the divine omnipotence,
while here this passage would be- merely an ordinary one. I
have already said something about it above (chap. 21, § 41),
where I also remarked that it is not true that a body loses as
much motion as it gives to another ; which they seem to conceive
as if motion were a substantial thing and resembled salt dissolved
in water, which comparison is actually the one M. Eoliaut,2 if
I mistake not, has used. I add here that this is not even the
most usual case, for I have elsewhere demonstrated that the
same quantity of motion is maintained only when the two
bodies which come into collision proceed in one and the same
direction before the collision and still proceed in one and the
same direction after the collision. It is true that the 'veritable
laws of motion are derived from a cause superior to matter.
As for the power of producing motion by thought, I do not think
we have any idea of it, as we have no experience of it. The
Cartesians themselves admit that souls cannot give a iiewr
force to matter, but they pretend that they give it a new
determination or direction of the force it has already. For
myself, I maintain that souls change nothing in the force nor
in the direction of bodies ; that the one would be as incon
ceivable and unreasonable as the other, and that you must
avail yourself of the pre-established harmony in order to
explain the union of the soul and the body.]
Ph. It is worth our consideration whether active power is
not the proper attribute of spirits and passive power of
bodies ? Whence we might conjecture that created spirits,
1 Cf. ante, p. 176. — TR.
2 James Rohaut or Rohault, 1020-1(575, a French physicist, a follower of
Descartes. His chief work, the Physics, was written in French, and trans
lated into Latin, with valuable notes, by Dr. Samuel Clarke, 1675-1725), and
into English by his brother Dr. John Clarke. It was a text-book in the Uni
versity of Cambridge, until supplanted by the treatises of Sir Isaac Newton.
The original work first appeared in 1671, and enlarged, in two vols., in 1682.
Clarke's Latin version, 8vo., in 1697; the 4th and best edition, Jucobi Rohaulti
Phyawa, 8vo., 1718.— TR.
234 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
being active and passive, are not totally separate from simply
passive matter ; and that these other beings, which are active
and passive at the same time, partake of both.
Th. [These thoughts greatly please me and entirely express
my conviction, provided you explain the word spirit so gener
ally that it comprises all souls, or rather (to speak still more
generally) all the entelechies or substantial unities, which are
analogous to spirits.]
§ 31. Pli. I much wish that you would show me in the
notion we have of spirit anything more confused ] or nearer a
contradiction than what the very notion of body includes. 1
mean infinite divisibility.
Th. [What you here say further in order to make evident
that we understand the nature of the spirit as well or better
than that of the body is very true ; and Fromondus,2 who has
published a book, De compositione continui, was right in enti
tling it Labyrinth. But the question arises from a false idea
you have of the nature of body as well as of space.]
§ 33. Ph. The idea of God indeed comes to us as others
do, the complex idea of God we have being composed of the
simple ideas which we receive from reflection and which we
extend by the idea we have of the infinite.
Th. [Upon that question I refer to what I have already
said in several places in order to make evident that all these
ideas, and particularly that of God, are in us originally, and
that we only make ourselves take notice of them, and that
above all, the idea of the infinite is not formed by an extension
of finite ideas.3]
§ 37. Ph. The majority of the simple ideas which compose
our complex ideas of substances are, properly considered, only
powers, whatever our inclination to take them as positive quali
ties.
1 Locke's word is "perplexed," Philox. Works, Vol. 1, p. 443 (Bohn's ed.).
-TR.
- Libert Froidmont or Fromont — Latin, Fromondus — 1587-1G53, a Flemish
theologian, Professor of Philosophy and Theology in the University of Lou-
vain. His theological, philological, and scientific knowledge was very exten
sive. Descartes esteemed highly both his knowledge and his person. Cf.
Descartes' letters. His hook, Labyrinthus sire de compositione contiutrl, ap
peared at Antwerp in 1(531. — TR.
3 Cf.ante, pp. 1(5, 17; New Essays, Book II.. chap. 14, § 27, Th., and note 1,
ante, p. 158; chap. 17, § 1, Th., ante, p. 1(52. — TR.
en. xxv] OX HUMAN UNDERSTANDING
Tit. [I think that the powers, which are, not essential to
substance and which include not only an aptitude, but also a
certain tendency, are properly what is or ought to be under
stood by real qualities.'}
CHAPTER XXIV
OF COLLECTIVE IDEAS OF SUBSTANCES
§ 1. Ph. After simple substances we come to the aggregates.
Is it not true that the idea of this mass of men composing an
army, is as much a single idea as that of one man?
Th. [You are right in saying that this aggregate (ens per
aijiji'^ijationem, to use the language of the school), makes one
single idea, although, properly speaking, this mass of sub
stances does not form in truth one substance. This is a result
to which the soul by its perception and its thought gives its
last achievement of unity. You may, however, say in a sense
that it is something substantial, i.e. comprising substances.]
CHAPTER XXV
OF RELATION
§ 1. Ph. It remains to consider the ideas of relations which
are the poorest in reality. When the mind regards one thing
in comparison with another, this is a relation or respect,1 and
the denominations or relative terms, which are produced, are
like so many marks which serve to lead our thoughts beyond
the subject to something distinct from it, and these two arc
called subjects of the relation (relata).
Tli. [Relations and orders have something of the essence of
reason, although they have their foundation in things ; for we
can say that their reality, like that of eternal truths and possi
bilities, comes from the supreme reason.]
§ ,">. Ph. There may, however, be a change of relation with
out any change happening in the subject. Titius, whom to-
i Locke's word, PhiJmt. Wurk'tt, Vol. 1, p. 449 (Bolm's ed.).— TK.
236 LEIBXITZ'S CRITIQUE OF LOCKE [BK. n
day I consider as a father, ceases to be such to-morrow without
any change being made in himself, by the sole fact of his
son's death.
Th. [That statement may very well be made in view of
things which are perceived ; although in metaphysical strict
ness it is true that there is no entirely exterior denomination
(denominatio pure extrinseca) because of the real connection ol
all things.]
§ C. Ph. [I think that relation is only between two things.]
Th. [There are, however, examples of relation between sev
eral things at once, as that of order or that of a genealogical
tree, which expresses the rank and connection of all the terms
or members, and even a figure like that of a polygon includes
the relation of all the sides.]
§ 8. Ph. It is well to consider also that the ideas of rela
tions are often clearer than those of the things which are the
subjects of the relation. Thus the relation of father is clearer
than that of man.
Th. [That is because this relation is so general that it may
also suit other substances. Moreover, as a subject may have
clearness and obscurity, the relation might be grounded in the
clear. But if the form itself of the relation involved the
knowledge of that which is obscure in the subject, it would
participate in this obscurity.]
§ 10. Ph. The terms which necessarily lead the mind to other
ideas than those which are supposed really to exist in the
thing to which the term or word is applied are relative ; the
others are absolute.
Th. [You have well added this " necessarily " and you might
add " expressly " or " at first," for you can think of black, for
example, without thinking of its cause ; but it is by remaining
within the limits of a knowledge which presents itself at first
and which is confused or very distinct, but incomplete ; the
one when there is no resolution of the idea, the other when
you limit it. Otherwise there is no term so absolute or so
loose as not to include relations and the perfect analysis of
which does not lead to other things and even to all others ; so
that you can say that relative terms indicate expressly the rela
tion they contain. I here oppose the absolute to the relative,
and it is in another sense that I have opposed it above to the
limited.']
CH. xxvi] ON HUMAN UNDERSTANDING
CHAPTER XXVI
OF CAUSE AXD EFFECT AND SOME OTHER RELATIONS
§§ 1, 2. Ph. Cause is that which produces a simple or in-
complex idea ; effect is that which is produced.
Th. [I see, sir, that you often understand by idea the objec
tive reality of the idea or the quality which it represents. You
define only efficient cause, as I have already remarked above.
You must admit that, in saying that efficient cause is that
which produces and effect that which is produced, you make
use only of synonyms. It is true that I have heard you say a
little more distinctly, that cause is that which makes another
thing commence to exist, though this word "makes" passes
over also the principal difficulty entirely. But that will be
explained better elsewhere.]
Ph. In order further to touch some other relations, I remark
that there are terms employed to designate time which are
ordinarily regarded as signifying only positive ideas, which
are nevertheless relative, as young, old, etc., for they involve a
relation to the ordinary duration of the substance to which
you attribute them. Thus a man is called young at the age of
twenty years, and very young at the age of seven years. But
we call a horse old at twenty years, and a dog at seven. But
we do not say that the sun and the stars, a ruby or a diamond,
is young or old, because we do not know the ordinary periods
of their duration. § 5. The same is true regarding place or
extension, as when a thing is said to be liujli or low, great or
small. Thus a horse which will be large according to the idea
of a Welshman, appears very small to a Fleming ; each thinks
of the horses which are raised in his country.
Th. [These remarks are very good. It is true we some
times swerve a little from this sense, as when we say that a
thing is old when comparing it not with those of its kind, but
with other kinds. For example, we say that the world or the
sun is very old. Some one asked Galileo if he believed that
the sun was eternal. He replied: etertio nd ma ben antico —
eternal, no, but very ancient.
238 LEIBNITZ'S CRITIQUE OF LOClvE [BK. n
CHAPTER XXVII
WHAT IDEXTITY OK DIVERSITY IS
§ 1. Ph. A relative idea of the greatest importance is that
of identity or diversity. We never find and we cannot conceive
it possible that two things of the same kind exist in the same
time in the same place. Therefore when we ask whether a
thing is the same or not, the question always relates to a thing
which at such a time exists in such a place ; whence it follows
that a thing cannot have two beginnings of existence, nor two
things one beginning only in relation to the time and the
place.
Tli. [It is always necessary that besides the difference of
time and place there be an internal principle of distinction, and,
though there are many things of the same kind, it is never
theless true that none of them are ever perfectly alike : thus
although time and place (i.e. external relation) serve us in
distinguishing things which we do not easily distinguish by
themselves, the things do not cease to be distinguishable in
themselves. The essence (le precis) of identity and diversity
consists, then, not in time and place, although it is true that
the diversity of things is accompanied by that of time or of
place, because they bring with them different impressions of
the thing ; not to say that it is rather by the things that one
place or one time must be distinguished from another, for in
themselves they are perfectly alike, but they are not, there
fore, substances or complete realities. The mode of distin
guishing which you seem to propose here, as unique in things
of the same kind, is based upon the supposition that penetra
tion is not conformable to nature. This supposition is reason
able, but experience indeed makes it evident that it is not
closely applied here, when the question concerns distinction.
We see, for example, two shadows or rays of light which in
terpenetrate, and we might invent for ourselves an imaginary
world wherein bodies would act in the same way. But we do
not cease to distinguish one ray from another by the very
rate of their passage even when they cross each other.]
CH. xxvn] OX HUMAN UNDERSTANDING 239
§ 3. Ph. What is called the principle of individuation (prin-
cipiuni individuatioms) in the schools, where they torment
themselves so much to know what it is, consists in existence
itself which determines each being to a particular time and
place incommunicable to two beings of the same kind.
Th. The principle of individuation l reappears in individuals
in the principle of distinction of which I just spoke. If two
individuals were perfectly alike and equal and (in a word')
indistinguishable in themselves, there would be no principle
of individuation; and I even venture to assert that there
would be no individual distinction or different individuals
under this condition. This is why the notion of atoms is
chimerical, and arises only from the incomplete conceptions
of men. For if there were atoms, i.e. bodies perfectly hard
and perfectly unalterable or incapable of internal change and
capable of differing among themselves only in size and shape,
it is plain that in the possibility of their being of the same
shape and size they would then be indistinguishable in them
selves, and could be distinguished only by means of external
denominations without an internal basis, which is contrary to
the highest principles of reason. But the truth is that every
body is alterable, and indeed actually changes so that it differs
in itself from every other. I remember that a distinguished
princess,2 who is of a pre-eminently excellent mind, said one
1 Leibnitz discussed this principle in his disputation for the decree of
Bachelor of Philosophy, entitled, Disputatio metaphysica de principio itidi-
ridiii, which in his sixteenth year he publicly defended at Leipzig, March 30,
1663; cf. Guhrauer, Leibniz. Leben, 1, 27 xq. This piece is found in Gerhardt,
4, 15-26, where the title-page gives the date of the public defence, May 30,
1663; Erdmann, 1-5; it has also been edited, with an extended critical intro
duction, from a copy found in the Library at Hannover by Dr. G. E. Guhrauer,
and published at Berlin in 1837. J. H. von Kirchmann has published a German
translation with elaborate and extensive notes in his Philos. liibliothek, Bd.
81, Die Me in. philoft. wichtt Schriften G. W. Leibniz ; Bd. 82, Erlauterunyen.
For a recent discussion of the principle of individuality, cf. R. Eucken, The
Fundamental Concepts of Mod. Philos. Thought, pp. 231-248. New York,
1880. — TR.
2 Sophie Charlotte, 1668-1705, the first Queen of Prussia, the friend and in
a certain sense the pupil of Leibnitz in philosophy. The Theodicee originated
in his philosophical conversations with her. Cf. Gerhardt, 6, 39; Erdmann,
474 b. Leibnitz's correspondence with her is found in O. Klopp, J)ie Werke
von Leibniz, Vol. 10, Hannover, 1877 ; the letters of philosophical importance
in Gerhardt, 3. 343 sq. ; 6, 488 sq. ,- 7, 544 ; the letter in G.6, 499s<7. is translated
in Duncan, Philos. Works of Leibnitz, 149 xq. Cf. also Kuno Fischer, Gesch.
d. n. Philots., Vol. 2, p. 261 sq., 3d ed., 1889. — TR.
240 LEIBNITZ'S CKITIQUE OF LOCKE [BK. IT
day while walking iu her garden that she did not believe
there were two leaves perfectly alike. A gentleman of dis
tinction, who was walking with her, thought he would easily
h'nd some. But although he searched long, he was convinced
by his eyes that he could always note the difference. We see
by these considerations, hitherto neglected, how far Ave have
wandered in philosophy from the most natural notions, and
how far we have departed from the great principles of true
metapliysic.]
§ 4. Ph. That which constitutes the unity (identity) of one
and the same plant is the possession of such an organization
of parts in a single body, as participates in a common life
which endures while the plant subsists, although the parts
change.
Th. [The organization or configuration without an existing
principle of life, which I call a monad, would not suffice to
cause the continuance of idem numero or the same individual ;
for the configuration can abide specifically without abiding l
individually. When a horseshoe is changed into copper in a
mineral spring of Hungary, the same figure in kind remains,
but not the same as an individual; for the iron is dissolved,
and the copper, with which the water is impregnated, is pre
cipitated and insensibly takes its place. Now figure is an
accident which does not pass from one subject to another (de
subjecto in subjectum). So we must say that .bodies as well
organized as others do not remain the same in appearance,
and, speaking strictly, not at all. It is almost like a river
which always changes its water, or like the ship of Theseus
which the Athenians were always repairing.2 But as regards
1 Erdmann and Jacques omit " specifiquement, sans demeiirer," the reading
of Gerhard t. — TR.
2 Cf. Plato, PhsBdo. 58 A; Xenophon, Memorabilia, 4, 8, 2. The sacred
ship, sent yearly to Delos by the Athenians in consequence of a vow made to
Apollo by Theseus when on his way to Crete with the seven youths and seven
maidens, the annual tribute of the Athenians to the Minotaur, that- if rescued
he would send annually to Delos a ship with gifts and saci'ifices as a thank-
offering for their deliverance, was repaired piece by piece as necessary, so
that in form and appearance it remained the same old ship in which Theseus
himself sailed, while its substance continually changed. The vessel served
the philosophers as an instance in discussions concerning identity and what
constitutes it, and as an illustration of a numerical substance continuously
the same, though constantly changing by the decay and rejection of old and
the growth and acquisition of new parts, as in the case of the living body.
— TK.
CH. xxvii ] ON HUMAN UNDERSTANDING 241
substances, which are in themselves a true and real substantial
unity, to which may belong actions properly called vital, and
as regards substantial beings, quce uno spiritu continentur, in
the words of an. ancient jurisconsult,1 i.e. which a certain
indivisible spirit animates, you are right in saying that they
remain perfectly the same individual through this soul or this
spirit which constitutes the ego in thinking beings.]
§ 5. Ph. The case is not very different in animals and in
plants.
Th. [If vegetables and animals have no soul, their identity
is only apparent ; but if they have, individual identity is in
truth strictly speaking there, although their organized bodies
do not preserve it.]
§ 6. Ph. This also shows wherein the identity of the same
man consists, viz. in the fact alone that he enjoys the same
life, continued by particles of matter which are in a perpetual
flux, but which in this succession are vitally united with the
same organized body.
Th. [That may be understood in my sense. In fact, the
organized body is not the same from one moment to another ;
it is only equivalent. And if it were not related to the soul,
there would no longer be the same life or vital union. Thus
this identity would be only apparent.]
Ph. Whoever shall connect the identity of man with any
thing else than a well-organized body, in a certain instant, and
which thence continues in this vital organization by a succes
sion of different particles of matter which are united to it,
will have difticulty in making an embryo, a man of years, a
fool, and a wise man the same man, unless it follows from this
supposition that it is possible for Seth, Ismael, Socrates, Pilate,
St. Augustine 2 to be one and the same man, . . . and this would
agree still worse with the notions of those philosophers who
recognize transmigration and believe that men's souls can be
sent for punishment of their irregularities into the bodies of
animals ; for I do not believe that any one who was assured
that the soul of Heliogabalus existed in a hog would mean
that this hog was a man, and the same man as Heliogabalus.
1 Sextus Pomponius, died 138 A.D. The phrase occurs in the Digest, 41, 3,
30, Vol. 2, }>. 51% ed. Th. Mornmsen, Berlin: Weidmann, 1870. — TR.
a Locke has " St. Austin," Philvx. Works, Vol. 1, p. 463 (Bolm's ed.). — Tu.
K
242 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
Th. [There is here a question of name and of thing. As for
the thing, the identity of one and the same individual sub
stance can be maintained only by the conservation of the same
soul, for the body is in a continual flux, and the soul does not
dwell in certain atoms appropriated to itself, nor in a little
incorruptible (indomptable) bone, such as the Luz l of the
Rabbis. Moreover there is no transmigration by which the
soul wholly leaves its body and passes into another. It keeps
always, even in death, an organized body, a part of the pre
ceding, although what it keeps is always subject to insensible
dissipation and to reparation, and indeed to undergoing in a
certain time a great change. Thus instead of a transmigra
tion of the soul there is a transformation, envelopment, or
development, and finally a fluxion of the body of this soul.
Van Helmont,2 the son, thought that souls pass from body to
body, but always within their kind, so that there will always
be the same number of souls of one and the same kind, and
consequently the same number of men and of wolves, and that
the wolves if diminished or extirpated in England would be
proportionally increased elsewhere. Certain meditations pub-
1 The bone which the Jews regarded as incapable of decay, remain ing until
the last clay and forming the nucleus of the resurrection body. Schaarschmidt
says: " According to the opinion of the Rabbis, says Ulrich in his note to this
place, the body which we are to receive at the resurrection is already at hand
in our backbone. This body or bone, l*h (Luz), as it is properly called, tiiey
held for this reason to be incorruptible. In the Jalkut chadasch, Fol. 142,
title Maschiach, n. 44, the following account is given of it: This bone decays
not, and the holy giving God will make it soft with the dew, and out of it will
build the body. The reason why this little bone is not to be exposed to cor
ruption, they place in the fact that it has not enjoyed the pleasures of this
world, as the rest of the members. This doctrine is with them no empty
speculation. The old Rabbis of blessed memory have not only seen this bone,
but have found it actually so strong and hard that their hammer and rock
flew in pieces before this little bone was injured in the least. See Ankath
Rochel in the 4th part," etc. — TR.
2 Fran£ois Mercure van Helmont, 1618-1698, a particular friend of the
Countess of Connaway, in whose Opuscnla philosophi<-a, Bk. I., chap. 6, §§ 7,
8, and chap. 7, § 4, London, 1690, this view of his is found in detail. On
Leibnitz's relations with Van Helmont, cf. Stein, Leibniz and Spinoza, pp.
210 sq., and the references in Stein's notes; also Beilayen, XV., XVI., op. cit.
pp. 329-337. Leibnitz composed for him, at the request of his cousin, the
Baroness of Merode, a Latin epitaph; cf. Burckhard, Historia Biblioth. A\t-
(justsK, II., p. 326; also Stein, op. cit. pp. 336-337. Leibnitz treats of him and
his doctrine in his Miscellanies, cf. Otium Hanoveranum, ed. J. F. Feller,
pp. 22(3-230, Lipsise, 1718. — TR.
CH. xxvnj ON HUMAN UNDERSTANDING 243
lished in France would also seem to tend in that direction. If
transmigration is not taken strictly, i.e. if any one thought
that souls dwelling in the same subtile body change only from
a coarser body, it would be possible, even to the passage of
the same soul into a body of a different kind after the fashion
of the Brahmins and Pythagoreans. But all that is possible
is not for that reason conformed to the order of things. But
the question whether, in case such a transmigration were true,
Cain, Ham, and Ismael, supposing, according to the Rabbis,
they were the same soul, would deserve to be called the same
man, is only one of name ; and I have observed that the cele
brated author, whose opinions you have maintained, recognizes
and explains it very well (in the last paragraph of this chapter).
The identity of substance would occur therein, but in case
there were no connection of memory between the different
persons, as the same soul would make, there would not be
sufficient moral identity to say that it would be one and the
same person. And if God willed that the human soul should
go into the body of a hog, forgetting the man and performing
no rational acts, it would not constitute a man. But if in the
body of the animal it had the thoughts of a man, and even of
the man whom it animated before the change, like the Golden
Ass of Apuleius, one would perhaps have no difficulty in say
ing that the same Lucius, who had come into Thessaly to see
his friends, lived under the ass's hide, where Photis had put
him in spite of herself, and wandered from master to master
until the roses he ate restored him to his natural form.1
i Cf. Apuleius, Metamorph., Bk. III., Vol. 1, pp. 229 sq. ,- Bk. XI., pp. 770 sq.,
edition in 6 vols., paging continuous, A. J. Valpy, London, 1825. The Meta
morphoses is in contents very similar to a work entitled, AOU'KIOS 77 o^os (Lucius
or Ass), ascribed to Lucian, a contemporary of Apuleius who flourished about
160 A.D., and is most probably an imitation of it. The incidents and adven
tures in both are nearly identical, the names only being changed, both writers,
however, calling the hero Lucius. In the course of his adventures Lucius
became involved in a love-affair with a waiting-woman by the name of Fotis,
whose mistress practised the art of magic, and changed at will herself and
others into various animals by the use of certain ointments. Lucius, very
desirous to learn all about- this wonderful art, finally persuaded Fotis, who
claimed that she understood her mistress's art, to try it on him. She did so,
intending to change him into an owl, into which form her mistress in the
sight of them both had just changed herself, but in her haste and confusion
using the wrong ointment, she changed him, "in spite of herself," into an ass.
The work of Apuleius is much more extended than that of Lucian, and, in
244 LEIBNITZ'S CRITIQUE OF LOCKE [UK. n
§ 9. Ph. I think we can boldly advance the idea that who
ever of us saw a creature made and formed like himself,
although it had never exhibited more reason than a cat or a
parrot, would not cease to call it a man ; or if he heard a
parrot discoursing rationally and in a philosophical manner
would call or think it only a parrot, and would say of the
former of these animals that it is an uncultivated man, dull
and destitute of reason, and of the latter that it is a parrot full
of intelligence and good sense.
Th. [ I should be more of the same opinion upon the second
point than upon the first, although there is still something to
be said thereupon. Few theologians would be venturesome
enough to agree at once and absolutely to the baptism of an
animal in human form, but without appearance of reason, if
he were taken while young in the woods and some priest of
the Roman church should perhaps say conditionally, if you
are a man I baptize you; for they would not know whether
he is of the human race and whether a rational soul dwells
therein, and this might be an ourang-outang, an ape externally
very like a man, such as that one whom Tulpius x speaks of as
having seen, and that one an account of whose anatomy a
learned physician has published. It is certain (I admit) that
man can become as stupid as an ourang-outang, but the interior
of a rational soul would abide there in spite of the suspension
of the exercise of reason as I have explained above ; thus it is
a point of which we cannot judge by appearances. As for the
second case, nothing prevents there being rational animals of
a different kind from ourselves, as those inhabitants of the
poetic kingdom of the birds in the sun, where a parrot having
come from this world after its death, saved the life of a trav
eller who had treated him well here below. But if it hap
pened, as it happens in the country of the fairies or of Mother
spite of its irony, abounds in a mysticism not found in the \VKIOS ^ oi/o?. A brief
sketch of Lucian's work may be found in the Encyclopaedia Britannica,
9th ed., under the article "Lucius." On Apuleius, and the relation of his
work to that of Lucian, cf. Teuffel, Gexch. d. Rom. Lit., § 367, 3, 4th ed.,
Leipzig: B. G. Teubner, 1882; § 367, 1, 5th ed. by Ludwig Sclnvabe, Leipzig:
Teubner, 1890, and from this ed., the English translation in 2 vols., by Geo.
C. W. AVarr, M.A., Geo. Bell and Sons, London, 1891. — TR.
1 Nicolas Tulp, 1593-1674, a Dutch physician and magistrate, in Bk. III.,
chap. 56, of his Observationum weclico.rum libritres, Amsterdam, 1641, 8th ed.,
revised with additions, Leyden, 1752. — TR.
CH. xxvn] ON HUMAN UNDERSTANDING 245
Goose, that a parrot was a transformed daughter of a king and
became known as such while speaking, doubtless her father
and mother would caress her as their daughter whom they
thought they possessed though concealed under this strange
form. I should not oppose myself, however, to him who should
say that in the Golden Ass as the self or the individual re
mained for the sake of the same immaterial spirit, so Lucius
or the person remained for the sake of the apperception of
this ego, but that this is no longer a man ; as in fact it seems
necessary to add something of the figure and constitution of
the body to the definition of man, when we say that he is a
rational animal ; otherwise in my view the genii would also be
men.]
§ \). Ph. The word person carries with it a thinking and
intelligent being, capable of reason and reflection, that can
consider itself indeed as the same, as one and the same thing
which thinks at different times and in different places ; which
it does only by that consciousness l which it has of its own
acts. And this knowledge always accompanies our sensations
and our present perceptions [when they are sufficiently dis
tinguished, as 1 have more than once before remarked] and it
is by this that each one is to himself what he calls himself.
It is not considered in this case whether the same self is con
tinued in the same or in different substances. For since
consciousness 2 always accompanies thought, and is that which
makes each one to be what he calls himself and by which he
is distinguished from every other thinking being ; it is also in
this alone that personal identity consists, or that which makes
a rational being always to be the same ; and as far as this
consciousness can be extended over actions or thoughts already
past, so far the identity of this person extends, and the self
is at present the same as it was then.
Th. [I am also of this opinion that consciousness or the
perception of the ego proves a moral or personal identity.
And it is by this that I distinguish the incessdbility 3 of the
soul of an animal from the immortality of the soul of man ;
1 The French is "sentiment." — TR.
2 The French text is "la conscience (consciousness on conscienciosite),"
Gerhardt ; " consciosite," Erdmann and Jacques. — TR.
3 The French is " incessabilite," i.e. continuity or perpetuity. — TR.
246 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
both preserve physical and real identity, but as for man, he is
conformed to the rules of divine providence so that the soul
preserves also identity moral and apparent to ourselves, in order
to constitute the same person, capable consequently of feeling
chastisements and rewards. It seems that you, sir, hold that
this apparent identity could be preserved, if there were no
real identity. I should think that that might perhaps be by
the absolute power of God, but according to the order of things,
identity apparent to the person himself who perceives' the
same, supposes real identity to every proximate transition,
accompanied by reflection or perception of the ego, a perception
intimate and immediate naturally incapable of deception. If
man could be merely a machine and witli that have conscious
ness, it would be necessary to be of your opinion, sir ; but I
hold that this case is not possible at least naturally. Neither
would I say that personal identity and even the self do not
dwell in us and that I am not this ego which has been in the
cradle, under pretext that I no more remember anything of
all that I then did. It is sufficient in order to find moral
identity by itself that there be a middle bond of consciousness
between a state bordering upon or even a little removed from
another, although a leap or forgotten interval might be mingled
therein. Thus if a disease had caused an interruption of the
continuity of the bond of consciousness so that I did not know
how I came into the present state, although I remember things
more remote, the testimony of others could fill the void in my
memory. I could even be punished upon this testimony, if I
had just done something bad of deliberate purpose in an inter
val that I had forgotten a little after on account of this
disease. And if I had just forgotten all past things and1
would be obliged to let myself be taught anew even to my
name and even to reading and writing, I could always learn
from others my past life in my previous state, as I have kept
my rights without its being necessary for me to share them
with two persons, and to make me the heir of myself. All
this suffices to maintain moral identity, which makes the same
person. It is true that if others should conspire to deceive
me (as I might indeed be deceived by myself, by some vision,
dream, or illness, believing that what I had dreamed had hap-
1 Gerhardt reads: "et"; Erdmann and Jacques: " que," so that. — TK.
CH. xx vi i] ON HUMAN UNDERSTANDING 247
pened to me) the appearance would be false. But there are
cases in which we can be morally certain of the truth upon the
relation of another, and with God whose social connection
with us constitutes the principal point of morality, the error
cannot have place. As for the self, it will be well to dis
tinguish it from the phenomenon of self and from conscious
ness. The self constitutes identity real and physical, and the
phenomenon of self, accompanied by truth, joins thereto per
sonal identity. Thus not wishing to say that personal iden
tity extends no farther than memory, I would say still less
that the self or physical identity depends upon it. Eeal and
personal identity is proved with the utmost possible certainty
by present and immediate reflection ; it is proved sufficiently
for ordinary purposes by our memory of the interval or by the
conspiring testimony of others. But if God should change in
an extraordinary manner real identity, personal identity would
remain, provided man preserved the appearances of identity,
as well the internal (that is to say, consciousness) as the
external, like those which consist in that which appears to
others. Thus consciousness is not the sole means for consti
tuting personal identit}^ and the testimony of another or even
other proofs can supply it. But there is some difficulty if
contradiction occurs between those diverse appearances. Con
sciousness may be silent as in forgetfulness ; but if it should
alter very clearly things which were contrary to the other
appearances, we should be embarrassed in the decision and as
it were suspended sometimes between two possibilities, that
of the error of our memory and that of some deception in
external appearances.]
§ 11. Ph. [You will say] that the members of the body of
every man are a part of himself [and that thus, the body
being in a perpetual flux, the man cannot remain the same].
Th. [I should rather prefer to say that the I and the He are
without parts, because it is said, and with reason, that the
same substance, or the same physical ego, is really preserved.
But we cannot say, speaking according to the exact truth of
things, that the same whole is preserved when a part is lost.
Xow whatever has corporeal parts cannot fail to lose some of
them at every moment.]
§ 13. Ph. The consciousness which one has of his past
LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
actions cannot be transferred from one thinking substance to
another [and it would be certain that the same substance
abides, because we feel ourselves the same], if this conscious
ness were a single and indeed an individual act [i.e. if the act
of reflecting were the same as the act upon which you reflect
in perceiving it]. But as it is only an actual representation
of a past act it remains to be shown how it is impossible for
what has never really been to be represented to the mind as
truly having been.
Th. [Memory after an interval may deceive ; we have ex
perienced it often, and there are means of conceiving a natural
cause of this error. But present or immediate memory, or the
memory of what passed immediately before, i.e. the conscious
ness or reflection which accompanies internal action, cannot
naturally deceive ; otherwise we should not be certain indeed
that we think of this or that thing, for this statement is
made internally only of the action already past, and not in
connection with the action itself. Now if these internal,
immediate experiences are not certain, there will be no truth
of fact of which we can be assured. And I have already said
that there may be intelligible reasons for the error which ex
poses itself in perceptions mediate and external, but in those
immediately internal we cannot find any unless by recurring
to the omnipotence of God.]
§ 14. Pit. As for the question whether the same immaterial
substance remaining there may be two distinct persons, see
upon what it is based. It is this : If the same immaterial
being can be deprived of all consciousness (sentiment) of its past
existence, and lose it wholly, without the power of ever recov
ering it, so that beginning, so to speak, a new account from a
new period, it has a consciousness (conscience) which cannot
extend beyond this new state. All those who believe in the
pre-existence l of so^ds are evidently of this mind. I have seen
1 I.e. existence before this earthly life. The doctrine was set forth with
more or less fulness by the Pythagoreans, Plato, Philo, Origen, and more
recently, among others, by Lessing, Erziehunfi des Meiisc/ienf/eschlechtes,
§ 94 SQ. ; Kant, Die Religion innerhalb der Grenzen der blossen Vernunft,
Bk. I., 4; Julius Miiller, Die christ. Lchre von der Stinde. Bk. IV., chap. 4,
Vol. 2, pp. 486 .<?(/., Breslau, 1844, and English translation of the same, 2d ed.,
from the 5th German eel., Halle, 186(5, Vol. 2, pp. 357 sq., Edinburgh: T. & T.
Clark, 1868. The doctrine has been used chiefly to explain the origin of
CH. xxvn] ON HUMAN UNDERSTANDING 249
a man who was persuaded that his soul had been the soul of
Socrates ; and I can assure you that in the post he filled and
which was not one of little importance he passed for a very
rational man, and he appeared by his works which have seen
the light to lack neither intelligence nor learning. Now souls
being l indifferent to any portion of matter whatever this may be,
as far as we can know it by their nature, this supposition
(of the same soul passing into different bodies) involves
no apparent absurdity. But he who now has no conscious
ness of that which Nestor or Socrates ever did or thought,
does he or can he conceive himself the same person as Nestor
or Socrates? Can he take part in the actions of these two
ancient Greeks? Can he attribute them to himself or think
them his own actions rather than those of some other man
who has already existed? He is no more the same person
with one of them than if the soul now present in him had
been created when it began to animate the body which it now
possesses. This would no more contribute to make him the
same person as Nestor, than if some of the particles of matter
which once formed part of Nestor were now a part of this
man. For the same immaterial substance without the same
consciousness no more makes the same person to be united to
such or such a body than the same particles of matter, united to
a body without a common consciousness, can make the same
person.
Th. [An immaterial being or a spirit cannot be stripped
of all perception of its past existence. There remain for it
some impressions of all that has formerly happened to it, and
it even has some presentiments of all that will happen to it ;
but these feelings are most often too small to be capable of
being distinguished and perceived, although they may perhaps
sometime be developed. This continuation and bond of per-
evil or sin ; but it is an explanation which does not explain, its assumed solu
tion being merely an evasion of the real difficulty by pushing the problem
back unsolved into past time. Cf. O. Prleiderer, Religionsphilosophie auf
gesch. Grundlage, Vol. 2, p. 382, 2d ed., Berlin: G. Reimer, 1884; English
translation, Vol. 4, p. 29, London : Williams & Norgate, 1888. For a critique
of the theory as held by Julius Miiller, c/. I. A. Dorner, System, d. christUchen
Glaubenslehre, § 77, 3; § 82, 2, Berlin : AVm. Hertz, 1881 ; English translation,
Edinburgh: T. & T. Clark, 1882. — TR.
1 Gerhardt and Jacques read: "les ames estant" ("e'tant," J.) ; Erdmann
reads: "taut." — TR.
250 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
ceplions constitutes in reality the same individual, but the
apperceptions (i.e. when past feelings are perceived), prove
besides a moral identity and make real identity appear. The
pre-existence of souls does not appear to us through our per
ceptions, but if it were true, it might sometime make itself
known. Thus it is not reasonable that the restitution of
memory becomes forever impossible, the insensible percep
tions (whose use I have set forth on so many important occa
sions) serving here, moreover, to preserve the seeds. The late
Henry More, a theologian of the English church, was con
vinced of the truth of pre-existence and has written in its
defence.1 The late M. Van Helmont, the son, went much
farther, as I just said, and believed in the transmigration of
souls, but always into bodies of one and the same species, so
that according to him the human soul always animated a man.
He believed with some Kabbis in the passage of the soul of
Adam into the Messiah as into the new Adam. And I do not
know but that he thought he had himself been some ancient,
altogether clever man that he was elsewhere. Now if this pas
sage of souls was true, at least in the possible way that I have
explained above (but which does not appear probable), i.e.
that souls, keeping their subtile bodies, pass at once into other
coarse bodies, the same individual would always subsist in
Nestor, in Socrates, and in any modern, and he could even
make his identity known to any one who would penetrate
sufficiently into his nature, on account of the impressions or
marks which would there remain of all that Nestor or Soc
rates have done, and which any genius sufficiently penetrat
ing could there read. But if the modern man had no means
internal or external of knowing what he had been, it would be
as far as the moral is concerned as if he had not been. But
it appears that nothing is neglected in the world in relation
even to the moral, because God is the monarch thereof \\ hose
government is perfect. Souls according to my hypothesis are
not indifferent regarding any portion of matter whatever, as it
seems to you ; on the contrary, they originally express those
portions to which they are and ought to be united by nature.
1 Cf. Opera, 1, 750-754, London, 1679; following the Kabbala, he thinks all
souls were created at the same time as the world, 2, 530; and, like Leibnitz,
regards them as always united with some kind of matter, 2, 395, 396. — TR.
CH. xxvn J ON HUMAN UNDERSTANDING 251
Thus, if they pass into a new body coarse or sensible, they
would always preserve the expression x of all that they had
perceived in the old, and it would even be necessary for
the new body to manifest it so that the individual continuity
will always have its real marks. But whatever our past state
may have been, the effect it leaves cannot always be for us
apperceivable. The clever author of the Essay on Understand
ing, whose views you had espoused, 'had remarked (Bk. II.,
chap. 27. On Identity, § 27) that a part of these suppositions
or fictions of the passage of souls, assumed as possible, is
founded upon the common view of the mind as not only inde
pendent of matter but also as indifferent to every sort of mat
ter. But I hope that what you have said, sir, on this subject
here and there will serve to clear up this doubt and to make
better known what is naturally possible. We see thereby
how the acts of an ancient might belong to a modern who had
the same soul, although he did not perceive them. But if he
should come to recognize it, still more would personal identity
follow. For the rest a portion of matter passing from one
body into another does not constitute the same human indi
vidual, nor what is called the ego, but it is the soul which
constitutes it.]
§ 16. Ph. It is, however, true that I am as much concerned
and as justly responsible for an action done a thousand years
since, which is now adjudged as mine by this present con
sciousness (self-consciousness2) thereof, as having been done
by myself, as I am for what I have just done in the preced
ing moment.
Th. [This view of having done something may deceive in
distant actions. Men have taken as true by force of repetition
what they dreamed, or what they invented ; this false view
may embarrass, but it cannot make them punishable, unless
others agree therewith. On the other hand, you can be respon
sible for what you have done, when you have forgotten it,
provided the action be verified elsewhere.]
§ 17. Ph. Every one finds every day that while his little
1 Gerhardt and Erdmann read: " 1'expression " ; Jacques: "I'impression."
— TR.
- Gerhardt's reading ; Erdmann and Jacques have, as before (p. 245, note 2),
"consciositc ou consciousness." — TR.
LEIBNITZ'S CRITIQUE OF LOCKE [UK. n
finger is comprehended under this consciousness, it constitutes
as much a part of himself (of him) as that which is most so.
Tli. [I have said (§11) why 1 would not advance the view
that my linger is a part of me ; but it is true that it belongs to
me and that it constitutes a part of my body.]
Ph. [Those who hold another view will say that] in the
event of this little linger being separated from the rest of the
body, if this consciousness accompanies the little finger and
leaves the rest of the body, it is evident that the little finger
would be the person, the same person, and that then the self
would have nothing to do with the rest of the body.
Tli. [Nature does not admit these fictions, which are de
stroyed by the System of Harmony or the perfect correspon
dence of the soul and the bod}7.]
§ 18. Ph. It seems, however, that if the body should con
tinue to live and to have its particular consciousness, in which
the little finger had no share, and that meanwhile the soul
was in the finger, the finger could not own any of the actions
of the rest of the body, and we could no longer impute them
to it.1
Tli. [The soul also which would be in the finger would not
belong to this body. I admit that if God caused conscious
nesses to be transferred to other souls, it would be necessary
to treat them in accordance with moral notions, as if they
were the same ; but this would disturb the order of things
without reason, and make a divorce between the appercepti-
ble and the truth, which is conserved by the insensible percep
tions, which would not be reasonable, because the perceptions
insensible at present may some day be developed, for there is
nothing useless, and eternity gives a large field for changes.]
§ 20. Ph. Human laws do not punish the madman for the
acts which the sober 2 man does, nor the sober man for what
the madman does, thereby making them two persons. Thus
they say : he is beside himself.
Th. [The laws threaten to chastise and promise to recom
pense in order to prevent bad and further good acts. Now a
madman may be such that the threats and promises do not
operate sufficiently upon him, reason no longer being master ;
1 Locke reads: " him," Philos. Work*, Vol. 1, p. 475 (Bohn's ed.). — TR.
2 Locke's word; Philos. Works, Vol. 1, p. 475 (Bohn's ed.). — TR.
CH. xxvii] ON HUMAN UNDERSTANDING 253
thus in proportion to his weakness the severity of the pain
should cease. On the other hand we wish the criminal to feel
the effect of the evil he has done in order that he may fear
further to commit crimes, but the madman not being sensitive
enough, we are well content to wait a good while in order to
execute the sentence which punishes him for what he did
when sober. Thus what the laws or the judges do in these
instances comes not from the conception of two persons.]
§ 22. Ph. In fact in the party whose opinions I represent
to you, this objection is made, that if a man who is drunk and
who is afterwards no longer drunk, is not the same person, he
should not be punished for what he did while drunk, since he
is no longer conscious of his act. But they reply that he is
altogether as much the same person as a man who during his
sleep walks and does many other things and who is responsi
ble for all the evil he has happened to do in that state.
Th. [There is much difference between the acts of a
drunken man and those of a true and recognized somnambu
list. We punish drunkards because they can avoid drunken
ness and can even have some memory of pain while drunk.
But it is not so much within the power of somnambulists to
abstain from their nocturnal walk and from what they do.
But if it were true that by giving them a good flogging we could
make them stay in bed, we should be right in doing it, and we
should not fail either, although this would be rather a remedy
than a punishment. In fact it is said that this remedy has
restored them.]
Ph. Human laws punish both in accord with a justice con
formed to the mode in which men understand things, because
in these sorts of cases they cannot certainly distinguish what
is real from what is counterfeit ; thus ignorance is not re
ceived as an excuse for what they have done while drunk or
asleep. The deed is proved against the one who has done it,
and you cannot prove in his case lack of consciousness.
Th. [The question is not so much about this, as about what
must be done when it has been verified, as it may be, that the
drunkard or somnambulist were beside themselves. In this
case the somnambulist would be considered only as a maniac ;
but as drunkenness is voluntary, and the disease is not, the one
is punished but not the other.]
254 LEIBNITZ'S CRITIQUE OF LOCKE [KK. n
Ph. But in the great and terrible day of judgment, when
the secrets of all hearts shall be uncovered, it is right to think
that no one will have to answer for what is wholly unknown
to him and that each one will receive what is due him, his
own conscience accusing or excusing l him.
Th. I do not know whether it will be necessary for the
memory of man to be exalted at the day of judgment in order
for him to remember all he had forgotten, or whether the
knowledge of others and above all of the just judge who can
not be deceived will not suffice. We might devise a fiction lit
tle agreeing with the truth, but nevertheless conceivable, to the
effect that a man at the day of judgment believed he had
been bad and that the same appeared true to all other created
spirits, who would be able to judge of it, without its having
been true : could we say that the supreme and just judge, who
alone knows the contrary, could condemn this person and
judge contrary to his knowledge ? - Yet it seems that that
would follow from the notion you gave of moral personality.
You will perhaps say that if God judges contrary to appear
ances he will not be sufficiently glorified and will bring pain
upon others ; but the reply could be made that he is for him
self his unique and supreme law, and that in this case others
should consider themselves mistaken.]
§ 23. Ph. Could we suppose either two distinct and incom
municable consciousnesses acting by turns in the same body,
the one constantly during the day, the other by night, or that
the same consciousness acts at intervals in two different bodies;
I ask if, in the first case, the day and night man, if I may
so express myself, would not be two as distinct persons as
Socrates and Plato, and in the second case would he not be a
single person in two distinct bodies ? It matters not that this
same consciousness which affects two different bodies, and
these consciousnesses which affect the same body at different
times, belong the one to the same immaterial substance, and
the two others to two distinct immaterial substances, which
introduce these different consciousnesses into these bodies,
1 Erdmann and Jacques omit: " on excuse." — TR.
2 Gerhardt reads : " juger centre ce qu'il sait?" Erdmann and Jacques:
" juger contre ce qu'ils font?" i.e. "pass a judgment contrary to what they
do." — TR.
en. xxvn] ON HUMAN UNDERSTANDING 255
since personal identity would equally be determined by the
consciousness, whether that consciousness were attached to
some individual immaterial substance or not. Further, an
immaterial thinking thing may sometimes lose sight of its
past consciousness, and recall it anew. Now suppose these
intervals of memory and forgetfulness return with every day
and night, then you have two persons with the same immate
rial spirit. Whence it follows that the self is not determined
by the identity or diversity of substance, which it cannot be
sure of, but only by the identity of consciousness.
Th. [I admit that if all the appearances were changed and
transferred from our spirit to another, or if God made an
exchange between two spirits, giving the visible body and the
appearances and consciousnesses of the one to the other, per
sonal identity, instead of being attached to that of substance,
would follow the constant appearances which human morality
must have in view ; but these appearances would not consist
in the consciousnesses alone ; and it will be necessary for God to
make the exchange not only of the apperceptions or conscious
nesses of the individuals in question, but also of the appear
ances which present themselves to others regarding these
persons, otherwise there would be a contradiction between
the consciousnesses of the one and the testimony of the others,
which would disturb the moral order of things. But you
must also agree with me that the divorce between the insensi
ble and sensible world, i.e. between the insensible perceptions
which would remain in the same substances, and the appercep
tions which would be changed, would be a miracle, as when
you suppose that God makes the vacuum ; for I have stated
above why that is not in agreement with the natural order.
Here is another supposition much more suitable : it may be
that in another place in the universe or at another time a globe
may be found which does not differ sensibly from this earthly
globe, in which we live, and that each of the men who inhabit
it does not differ sensibly from each of us who corresponds to
him. Thus there are at once more than a hundred million pairs
of similar persons, i.e. of two persons with the same appear
ances and consciousnesses ; and God might transfer spirits
alone or with their bodies from one globe to the other without
their perceiving it ; but be they transferred or let alone, what
256 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
will you say of their person or self according to your authors?
Are they two persons or the same? since the consciousness
and the internal and external appearance of the men of these
globes cannot make the distinction. It is true that God and
the spirits capable of seeing the intervals and external rela
tions of times and places, and even internal constitutions,
insensible to the men of the two globes, could distinguish
them ; but according to your hypotheses consciousness alone
discerning the persons without being obliged to trouble itself
with the real identity or diversity of the substance, or even
of that which would appear to others, how is it prevented
from saying that these two persons who are at the same time
in these two similar globes, but separated from each other by
an inexpressible distance, are only one and the same person ;
which is, however, a manifest absurdity. For the rest, speak
ing of what may be in the course of nature, the two similar
globes and the two similar souls of the two globes would
remain so only for a time. For since there is an individual
diversity, this difference must consist at least in the insensible
constitutions which must be developed in the course of time.]
§ 26. Ph. Suppose a man punished now for what he has
done in another life and of which he could cause himself to
have absolutely no consciousness ; what difference is there
between such treatment and that which would be done him in
creating him miserable ?
Tli. [The Platonists, disciples of Origen, some Hebrews
and other defenders of the pre-existence of souls believed that
the souls of this world were placed in imperfect bodies, in
order to suffer for the crimes committed in a preceding world.
But it is true, if they neither know nor have ever learned the
truth, neither by recall of memory, nor by any traces, nor by
the knowledge of another, you cannot call it punishment ac
cording to ordinary notions. There is, however, some room
for doubt, while speaking of punishments in general, whether
it is absolutely necessary that those who suffer should one day
learn the reason for their suffering, and whether it would not
very often suffice that better informed minds should find
therein a motive for glorifying the divine justice. However,
it is more likely, at least in general, that the sufferers will
know the reason of their suffering.]
en. xxvn] ON HUMAN UNDERSTANDING 257
§ 29. Ph. [Perhaps in the main you can agree with my
author who concludes his chapter on identity by saying : that
the question whether the same man abides, is a question of
name, according as you understand by man either the rational
spirit alone or the body alone of this form which is called
human, or finally the spirit united to such a body. In the first
case the spirit separated (at least from the coarse body) will
be still the man ; in the second an ourang-outang, perfectly
similar to us, reason excepted, would be a man ; and if man
were deprived of his rational soul and received a soul of an
animal, he would continue the same man. In the third case
both must remain together with the union itself; the same
spirit, and the same body in part, or at least equivalent, as
far as the sensible corporeal form is concerned. Thus you
could continue the same being physically or morally, i.e. the
same person without remaining man, in case you consider this
figure an essential to man according to this last sense.]
Th. [I admit that in this respect it is a question of name,
and in the third sense the same animal is as it were now
caterpillar or silk-worm and now butterfly, and some as it
were have imagined that the angels of this world were men in
a past world. But we have devoted ourselves in this confer
ence to discussions more important than those about the
meaning of words. I have shown you the source of true
physical identity ; I have made it appear that morality con
tradicts it no more than memory ; that they cannot always
assign physical identity to the person indeed, whose (iden
tity) is at stake, nor to those who are in connection with him;
but that nevertheless they never contradict physical identity
and never are completely1 divorced from it; that there are
always some created spirits who know or may know what it
is ; but that there is room to consider that what is indifferent
regarding the persons themselves can be so only for a time.]
1 Erdmann and Jacques omit : "entier." — TR.
LEIBNITZ'S CRITIQUE OF LOCKE [UK. n
CHAPTER XXVIII
OF SOME OTHER RELATIONS, AND ESPECIALLY OF MORAL
RELATIONS
§ 1. Ph. Besides the relations founded upon time, space,
and causality, of which we have just been speaking, there are
an infinite number of others, some of which I am going to
propose for discussion. Every simple idea capable of parts
and of degrees, furnishes an occasion for comparing the sub
jects in which it is found, for example, the idea of more (or
less or equally) white. This relation may be called propor
tional.
Th. [There may be, however, excess without proportion ;
and this is in reference to a magnitude which I call imperfect,
as when we say that the angle which the ray makes with the
arc of its circle is less than a right angle, for it is impossible
that there be a proportion between these two angles, or
between one of them and their difference, which is the angle
of contingence.]
§ 2. Ph. Another occasion of comparing is furnished by
the circumstances of origin which found the relations of father
and child, brothers, cousins, countrymen. With us people
seldom think of saying this bull is grandfather of such a calf,
or these two pigeons are cousins-german ; for languages are
proportioned to use. But there are countries in which men less
curious about their own pedigree than about that of their
horses have not only names for each particular horse, but also
for their different degrees of relation.
Th. [We can furthermore join the family idea and names
to those of relationship. It is true we do not observe under
the empire of Charlemagne and for a sufficiently long time
before and after family names in Germany, France, and Lom-
bardy. It is moreover not long that there have been families
(even noble) in the North who had no name, and in which a
man would be recognized in his natal place only by calling his
name and that of his father, and besides (in case he trans
planted himself) by joining to his own the name of the place
en. xxvin] ON HUMAN UNDERSTANDING 259
whence he came. The Arabs and the Turcomans have also the
same custom (I believe), having but few particular family
names, and content themselves with naming the father and
grandfather, etc., of any one, and they pay the same honor to
their valuable horses, which they call by a proper name and
the name of the father and even beyond. Thus they spoke of
the horses which the Monarch x of the Turks sent to the
emperor after the peace of Carlowitz ; 2 and the late count
of Oldenburg, the last of his branch, whose studs wrere
famous, and who lived a very long time, had genealogical
trees of his horses so that he could prove their nobility,
and went so far as to have portraits of their ancestors (imag
ines ma jorum) which were so much in demand among the
liomans. But to return to men, there are among the Arabs
and the Tartars names of tribes, which are like great families,
which are much enlarged in the course of time. And these
names are taken either from the progenitor as in the time of
Moses, or from the place of abode, or from some other circum
stance. Mr. Worsley, an observing3 traveller, who is informed
of the present state of Arabia Deserta, where he has been for
some time, affirms that in all the countries between Egypt and
Palestine, and where Moses passed, there are to-day only three
tribes, who can bring together five thousand men, and that
one of these tribes is called Sali from the progenitor (as I
believe) whose tomb posterity honors as that of a saint, casting
upon it dust which the Arabs put upon the heads of themselves
and their camels. For the rest consanguinity exists when there
is a common origin of those whose relation is considered; but
we could say there is alliance or affinity between two persons,
when they may have consanguinity with one and the same
person without there being any for that reason between them
selves, which happens through the intervention of marriages.
But as it is not customary to say that there is affinity between
husband and wife, although their marriage may cause affinity
in relation to other persons, it would perhaps be better to
say that there is affinity between those who would have con-
1 Erdmann and Jacques read: "grand Seigneur." — TR.
2 Jan. 2(5, 1(599. — TR.
3 Erdmann and Jacques read : "curieux"; Gerhardt reads: " observatif."
— TR.
260 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
sanguinity between themselves if husband and wife were
taken as one and the same person.
§ 3. Ph. The foundation of a relation is sometimes a moral
right, as the relation of a general of an army or of a citizen.
These relations depending upon the agreements men have
made between themselves are voluntary or by institution, and
may be distinguished from the natural. Sometimes the two
correlatives have each its name, as patron and client, general
and soldier. But it is not so always ; as, for example, it is not
so in the case of those who are related to the chancellor.
Tli. [There are sometimes natural relations which men have
invested and enriched with certain moral relations, as, for
example, children have the right to claim the legitimate por
tion of the estate of their fathers or mothers ; young persons
are under certain restraints and the aged have certain immu
nities. But it also happens that some relations are taken as
natural which are not so ; as when the laws say that the
father is he who married the mother within the time which
makes it possible for the child to be attributed to him ; and
tliis substitution of the instituted in the place of the natural is
sometimes only presumption, that is to say, a judgment which
causes that to pass as true which perhaps is not so, whilst its
falsity is not at all proved. Thus it is that the maxim : pater
est quern nuptice demonstrant is understood in Roman law and
among the most of the peoples where it is received. But they
tell me that in England it avails nothing in proving his alibi ;
provided he has been in one of the three kingdoms, so that
the presumption in that case changes into fiction or into what
some doctors c&ll prcesumtio juris et de jure.~\
§ 4. Ph. A moral relation is the conformity or disagreement
which is found between the voluntary acts of men and a rule
which makes us judge whether they are morally good or bad.
§ 5. And moral good or moral evil is the conformity or the
opposition which is found between voluntary acts and a cer
tain law which brings upon us good or evil (physical) by the
will and power of the lawgiver (or of him who wills to main
tain the law) and it is this we call reward and punishment.
Tli. [Authors, as clever as he whose views you, sir, repre
sent, are allowed to adapt their terms as they think proper.
But it is also true that according to this notion one and the
CH. xxvin] OH HUMAN UNDERSTANDING 261
same act would be morally good and morally bad at the same
time under different legislators, entirely as our clever author
understood virtue above as that which is praised, and conse
quently the same act would be virtuous or not according to
the opinions of men. ~Now that not being the ordinary sense
that is given to morally good and virtuous acts, I prefer for
myself, to take as the measure of moral good and of virtue
the invariable rule of reason which God is charged with main
taining. We can also be assured that by his mediation all
moral good becomes physical,1 or as the ancients say, every
thing virtuous is useful2; while in order to express the notion
of the author, it would be necessary to say that moral good or
evil is an imposed or instituted good or evil, which he who has
the power tries to make us follow or shun by punishments
and rewards. The good is that which by the general institu
tion of God is conformed to nature or to reason.]
§ 7. Ph. There are three sorts of laws: the divine law, the
civil law, and the law of opinion or reputation. The first is
the rule of sins or duties, the second of actions criminal or
innocent, the third of virtues or vices.
Th. [According to the ordinary sense of terms virtues and
vices differ from duties and sins only as habits differ from
1 What does Leibnitz here mean by " physical " ? Possibly " physical" is
here equivalent to " real," i.e. actual, concrete, objectively realized as distin
guished from that which is purely subjective and abstract, and exists in idea
only (<•/-'. Bk. II., chap. 27, § 9, Th. propejin., ante, p. 247, line 7, where the two
terms are united in one phrase " real and physical," and seem to be mutually
interpretative and emphatic). Or, possibly, "physical" is here used in the
sense of "natural," the meaning of the passage being that moral good is
realized by the mediation of God through the natural forces and in accord
with the natural laws of the universe, which with Leibnitz have their ultimate
source and ground in the nature of God and his choice of " the best and most
perfect," as the universal principle of creation. The true view of the world
is, according to Leibnitz, both physico-mechanical and moral-teleological, the
two finding a higher unity in this principle of "the best and most perfect,"
the moral-teleological prevailing in case of collision, because of this princi
ple and because the physical is in its last analysis and ground spiritual and
possessed of an inner teleological character which is realized by means of
mechanism while resting upon the principle of the divine choice of the best.
Cf. Discours de Metaphysique, § 19 sq., Gerhardt, 4, 444 sq. ; letter to Bayle,
G. 3, 54; Erdmann, 10H. — TR.
2 Cf. Cicero, De Offlciis, Bk. III., chaps. 3 and 7, who shows on the author
ity of Pansetius and others that the virtuous and the useful — honestum and
it tile — are identical, a chief point of the Stoic philosophy. Cf. also Zeller,
Die Philos. d. Griech., III., 1 [Vol. 5] , p. 212, 3d ed. 1880. — TR.
262 LEIBNITZ'S CRITIQUE OF LOCKE
actions, and virtue and vice are not understood as something
dependent upon opinion.1 A great sin is called a crime, and
the innocent is not opposed to the criminal but to the blame
worthy. The divine law 2 is of two sorts, natural and positive.
Civil law is positive. The law of reputation deserves the
name of law only improperly, or is comprised under the
natural law, as though I said, the law of health, the law of
the family, when actions naturally attract some good or evil,
as the approbation of another, health, gain.]
§ 10. Ph. The claim is in fact everywhere made that the
terms virtue and vice signify actions good and bad in their
nature, and so far as they are really applied in this sense, vir
tue agrees perfectly with the divine (natural) law. But what
ever the claims of men, it is evident3 that these names, con
sidered in their particular applications, are constantly and
solely attributed to such or such actions as in each country or
in each society are reputed honorable or shameful : otherwise
men would condemn themselves. Thus the measure of what is
called virtue and vice is this approbation or this contempt,
this esteem or this blame, which is formed by a secret or tacit
consent. For although men united in political societies have
resigned into the hands of the public the disposition of all
their forces, so that they cannot employ them against their
fellow-citizens beyond what the law permits, they nevertheless
always retain the power of thinking well or ill, of approval
or disapproval.
Th. [If the clever author, who thus explains himself, should
declare with you, sir, that it has pleased him to assign this
present arbitrary nominal definition to the terms virtue and
vice, we could only say that it is allowed him in theory for the
1 Leibnitz maintains, as against Locke's theory of relativity, the absolute
and objective character of Moral Law. It is objective and universal, not sub
jective and particular ; not dependent upon the opinions of men, but grounded
in "the general institution of God," and ultimately in his infinitely perfect
moral nature, and is thus valid for and binding upon all moral beings as such.
This is Moral Law absolute and ideal which changes not ; it is progressively
and approximately attained or realized in the history of the individual and
the race according to men's apprehension of its nature and requirements and
their strength of purpose and effort in its pursuit. — TR.
2 Cf. the discussion of Moral Law, in Principles and Practice of Morality,
pp. 79s</., by E. G. Robinson, D.D., LL.D., Ex-President of Brown University.
Boston: Silver, Burdett & Co., 1888. —TR.
3 Locke has: "visible," Philos. Works, Vol. 1, p. 488 (Bonn's ed.). — TR.
CH. xxvin] ON HUMAN UNDERSTANDING 263
convenience of expression for want perhaps of other terms ; but
we shall be obliged to add that this meaning is not conformed
to usage, nor indeed useful for edification, and that it would
sound ill in the ears of many people, if any one should intro
duce it into practical life and conversation, as this author
seems himself to admit in his preface. But it is (for us) to
go on farther here, and although you admit that men claim to
speak of that which is naturally virtuous or vicious according
to immutable laws, you maintain that in fact they mean to
speak only of that which depends 011 opinion. But it seems
to me that by the same reasoning you could further maintain
that truth and reason and all that could be named as most real,
depends upon opinion, because men are mistaken when they
judge of it. Is it not better then on all accounts to say, that
men understand by virtue as by truth, that which is conformed
to nature, but that they are mistaken often in its application ;
besides they are mistaken less than they think, for what they
praise ordinarily deserves it in certain respects. The virtue
of drinking, i.e. of well carrying wine, is an advantage, which
served Boiiosus, in conciliating the Barbarians and in drawing
from them their secrets.1 The nocturnal powers of Hercules, in
which the same Bonosus claimed to resemble him, were no less
a perfection. The craft of thieves was praised among the
Spartans, and it is not the skill, but the unseasonable use
which has been made of it, which is blamable, and those whom
we harass in (time of) complete peace may serve sometimes as
excellent partisans in time of war. Thus all depends upon the
application and the good or bad use of the advantages you pos
sess. It is also very often true and should not be taken as a
very strange thing, that men condemn themselves, as when they
do what they blame in others, and there is often a contradiction
between actions and words which scandalizes the public, when
what a magistrate or preacher does and defends leaps to the
eyes of the whole world.]
§ II.2 Ph. Everywhere that which passes as virtue is that
which is thought worthy of praise. Virtue and praise are often
designated by the same name. Sunt hie etiam sua prcemia
laudi, says Vergil (Aen. I. 461) and Cicero, Nihil habet natura
1 Cf. Vopiscus, Script, hist. Auyust., Vol. 2, pp. 213, 214, ed. Peter. — TR.
2 Gerhardt and Louke; Erdmann and Jacques have § 12.— TR.
264 LEIBNITZ'S ClilTTQUE OF LOCKE [UK. n
praestantius quam honestatem, quam laudem, quam dignitatem,
quam decus.1 (Qucest. Tuscul. Bk. 2. chap. 20) and he adds
a little after : Hisce ego pluribus nominibus unam rem declarari
volo.1
Tli. [It is true that the ancients have designated virtue by
the name honesty (Vhonneste), as when they have praised in-
cocttim generoso pectus honesto.2 It is true also that honesty
(Vhonneste) has its name of honor or of praise. But this
means not that virtue is that which is praised but that it is
that which is worthy of praise and which depends upon truth,
and not upon opinion.]
Ph. Many do not think at all seriously of the law of God, or
hope that they will one day be reconciled with its author, and
as regards the law of the state they flatter themselves with im
punity. But they do not think that he who does anything
contrary to the opinions of those with whom he associates, and
to whom he wishes to commend himself, can avoid the pain of
their censure and of their disdain. Xo one who retains any
consciousness of his own nature can live in society constantly
despised; this is the force of the law of reputation.
Tli. [I have already said that it is not so much the pain of a
law, as a natural pain wrhich the act draws upon itself. It is,
however, true that many people are but little concerned a.bout
it, because ordinarily, if they are despised by some on account
of some blameworthy act, they find accomplices or at least
partisans, who do not despise them, if they are ever so little
commendable in some other respect. They . forget even acts
the most infamous, and it often suffices to be bold and im
pudent like that Phormio of Terence in order that all may be
overlooked. If excommunication produced a truly constant
and general contempt, it would have the force of this law of
which our author speaks : and it had in fact this force with the
first Christians and for them took the place of the right, which
they lacked, to punish the guilty ; nearly as artisans maintain
certain customs among themselves in spite of the laws, through
1 The quotation is not exact. Cf. op. cit., ed. Klotz, Lipsiae, B. G. Teub-
ner, 1870, where the text reads thus: " Nihil onim habet prsestantius, nihil
quod magis expetat quam honestatem, quam laudem, quam dignitatem, quam
decus. Hisce ego pluribus nominibus unam rem declarari volo, sed utor, ut
quam maxime significem, pluribus." — TK.
2 Persius. /Sat. 2, 74. — TB.
CH. xxix] ON HUMAN UNDERSTANDING 265
the contempt which they show for those who do not observe
them. And it is this which has also maintained duels con
trary to the ordinances. It would be desirable for the public
to agree with itself and with reason in its praise and blame ;
and that the great above all do not encourage the bad by laugh
ing at their bad actions, in which it ofteiiest seems that not he
who has done them, but he who has suffered them is punished
by contempt and ridiculed. We shall see also generally that
men despise not so much vice as weakness and misfortune.
Thus the law of reputation would need to be greatly reformed,
and also to be better observed.]
§ 19. Ph. Before leaving the consideration of relations, I
would remark that we usually have a notion as clear or clearer
of the relation than of its ground. If I believed that Sempronia
took Titus from beneath a cabbage, as they used to tell little
children, and that afterwards she had had Cains in the same
manner, I should have as clear a notion of the relation of
brother between Titus and Caius, as if I had all the knowledge
of the mid wives.
T/i. But when they once said to a child, that his little
brother, who had just been born, had been drawn from a well
(a reply which they make use of in Germany to satisfy the
curiosity of children upon this subject) the child replied that
he wondered that they did not throw him back again into the
same well when he cried so much and disturbed his mother.
The fact is this explanation did not make him know any rea
son for the love his mother showed for the child. We can say
then that those who do not know the ground of relations have
only concerning them what I call thoughts, surd in part and
insufficient, although these thoughts may suffice in certain
respects and upon certain occasions.]
CHAPTER XXIX
OF CLEAR AND OBSCURE, DISTINCT AND CONFUSED IDEAS
§ 2. Ph. We come now to some differences of ideas. Our
simple ideas are clear when they are such as the objects them
selves, from whence they are received, represent or may
206 LEIBNITZ'S CRITIQUE OF LOCKE [UK. n
represent them with all the circumstances requisite to a well-
ordered sensation or perception. While the memory retains
them in this way, they are in this case clear ideas, and so far
as they lack this original exactness or have lost anything so
to speak of their first freshness, and are, as it were, tarnished
or faded by time, so far are they obscure. Complex ideas are
dear, when the simple ideas which compose them are clear and
the number and order of these simple ideas are fixed.
Th. [In a brief discourse on ideas,1 true or false, clear or
obscure, distinct or confused, inserted in the " Leipsic Acts "
of the year 1684, I have given a definition of clear ideas,
common to the simple and complex and which gives the rea
son of what you say here. I said then that an idea is clear
when it suffices to recognize and distinguish the thing: as
when I have a very clear idea of a color, I shall not take
another instead of that which I ask for, and if I have a .clear
idea of a plant, I shall distinguish it among other neighboring
ones; without this the idea is obscure. I believe that we have
but few perfectly clear ideas of sensible things. There are
colors which approach each other in such a way that we can
not distinguish them by memory, and yet we will sometimes
distinguish them by placing one near the other. And when
we think w^e have fully described a plant, we can bring one
from the Indies which will have all we have put into our
description and which will not cease making itself known as
a different species : thus we can never perfectly determine
species iiifamce, or the lowest species.]
§ 4. Ph. As a clear idea is that whereof the mind has such
a full and evident perception as it receives from an external
object operating duly upon a well-disposed organ ; so a distinct
idea is that wherein the mind perceives a difference, which
distinguishes it from every other idea ; and a confused idea is
that which cannot be sufficiently distinguished from another
from which it should be different.
Th. [According to this notion which you give of the dis
tinct idea, I do not see how you distinguish it from the clear
idea. This is why I have been wont to follow here the lan
guage of Descartes, with whom an idea may be clear and con-
1 Meditationes de Cof/nitione, Veritate et Ideis. Cf. ante, p. 14, note 2;
p. 227, note 3. — TR.
CH. xxix] ON HUMAN UNDERSTANDING 267
fused at the same time ; and such are the ideas of sensible
qualities, appropriate to the organs, such as color or heat. They
are clear, for they are easily recognized and distinguished the
one from the other, but they are not distinct, because they are
not distinguished by what they include. Thus we cannot give
a definition of them. We make them known only by examples,
and for the rest we must say it is an indefinite somewhat,
until we can decipher its contexture. Thus although in
our view distinct ideas distinguish one object from another ;
nevertheless, as the ideas clear, but confused in themselves, do
so also, we call distinct not all those which are very discrimi
nating or which distinguish objects, but those which are well
distinguished, i.e. which are distinct in themselves and 'dis
tinguish in the object the marks which make it known, which
an analysis or definition of it gives ; otherwise we call them
confused And in this sense the confusion which reigns in
ideas can be exempt from blame, being an imperfection of our
nature ; for we cannot discern the causes, for example, of odors
and tastes, nor the content of these qualities. This confusion
can, however, be blameworthy, when it is important and
within my power to have distinct ideas, as, for example, if I
took adulterated gold as the true, for want of making the
necessary assays which contain the marks of good gold.
§ 5. Ph. But you will say that there is no idea confused (or
rather according to your view, obscure) in itself1 for it can be
only such as it is perceived by the mind, and that distin
guishes it sufficiently from all others. § 6. And in order to
remove this difficulty it is needful to know that the defect of
ideas is related to names, and what renders it faulty is the
fact that it can as well be designated by another name as the
one which we use to express it.
Th. [It seems to me that we ought not to make this depend
upon names. Alexander the Great had seen (they say) in a
dream a plant able to cure Lysimachus, which has since
been called Lysimachia, because it effectually cured this friend
of the king. When Alexander had a quantity of plants
brought, among which he recognized that which he had seen
in his dream, if unfortunately he had not had a sufficient idea
of it to recognize it and had needed as Nebuchadnezzar a
1 Erdmann and Jacques omit: " en elle ineme." — TB.
268 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
Daniel to enable him to recall his dream, it is plain that the
idea he would have had of it would have been obscure and
imperfect (for it is thus I should prefer to call it rather than
confused), not for want of appositeness in a certain name, for
there was none, but for want of application to the thing, i.e.
to the plant which was to heal. In this case Alexander would
be reminded of certain circumstances, but he would have been
in doubt about others ; and the name serving us to designate
anything makes us, when we fail in the application to names,
fail ordinarily in regard to the tiring which is promised by
this name.]
§ 7. Ph. As complex ideas are the most subject to this
imperfection, it may arise from the fact that the idea is
composed of too small a number of simple ideas, as is, for
example, the idea of an animal which has the skin spotted, (a
term) which is too general, and which does not suffice to dis
tinguish the lynx, the leopard, or the panther, which are
besides distinguished by particular names.
Th. [If we were in the condition Adam was in before he
had given names to the animals, this defect would not cease
to have place. For supposing we knew that among the
spotted animals there is one which has extraordinarily pene
trating sight, but that we did not know whether it is a tiger
or a lynx, or some other species ; it is an imperfection not
to be able to distinguish it. Thus the question is not so
much about the name as about that which may give occa
sion for it, and which renders the animal worthy of a particu
lar name. It thereby appears also that the idea of a spotted
animal is good in itself, and without confusion and obscurity,
when it is to serve only the genus ; but when joined with
some other idea which is not sufficiently remembered it is
to designate the species, the complex idea is obscure and
imperfect.]
§ 8. Ph. There is an opposite defect when the simple ideas
which make up the complex idea are sufficient in number, but
too confused and involved, like some pictures, which appear
so confused that they must be only the representation of the
sky covered with clouds, in which case also we could not say
that there is confusion any more than if it were another pic
ture made to imitate that one ; but when we say that this
CH. xxix] ON HUMAN UNDERSTANDING 269
picture should make us see a portrait, we shall have reason
to say that it is confused because we cannot say whether
it is that of a man, or of a monkey, or of a fish, but it may be
that when we look at it in a cylindrical mirror, the confusion
will disappear, and that we shall see that it is a Julius Csesar.
Thus some mental paintings (if I may so express myself) can
not be called confused from any way in which the parts are
joined together ; for whatever these paintings are, they can
obviously be distinguished from every other, until they are
ranked under some ordinary name, to which we cannot see
that they belong any more than to some other name of a
different signification.
Th'. [This picture whose parts we see distinctly, without
noticing the result to which they in a certain way point,
resembles the idea of a heap of stones, which is truly confused
not only in your sense, but also in mine, so far as we have
distinctly conceived their number and * other properties. If
there were thirty-six of them (for example), we would not
know, looking at them heaped together without arrangement,
that they may produce a triangle or indeed a square, as in
fact they can, because thirty-six is a square as well as a tri
angular number. Thus it is that, in looking at a figure of a
thousand sides, we shall have only a confused idea of it, until
we know the number of the sides which is the cube of ten.
The question, then, is not of names but of the distinct proper
ties which are to be found in the idea when we have cleared
up its confusion. And it is sometimes difficult to find the
key, or the manner of looking at it from a certain point, either
by the intervention of a certain mirror or glass in order to see
the purpose of him who has caused the thing.]
§ 9. Ph. It cannot be denied that there is yet a third defect
in ideas, which depends in truth upon the bad use of names ;
it is when our ideas are uncertain or undetermined. Thus
we may see every day men who, making no difficulty of
availing themselves of the ordinary words of their mother
tongue, before they have learned their precise meaning, change
the idea which they attach to them almost as often as they
use them in their discourse. § 10. Thus we see how much
names contribute to this denomination of ideas distinct and
confused, and, without the consideration of distinct names
270 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
understood as signs of distinct things, it will be very difficult
to say what a confused idea is.
Tli. [I have, however, just explained it without considering
the names, whether in the case where the confusion is under
stood with you as what I call obscurity, or in that where it is
understood in my sense as the defect in the analysis of the
notion we have. And I have also shown that every obscure
idea is in fact indeterminate or uncertain, as in the example
of the spotted animal we have seen, where we know that some
thing further must be added to this general notion, without
clearly remembering it ; so that the first and third defect
which you have specified come to the same thing. It is, how
ever, very true that the abuse of words is a great source
of errors, for a kind of error in calculating occurs therefrom,
as if in calculating we did not notice carefully the place of
the counter, or if we wrote the figures so badly that we could
not distinguish a 2 from a 7, or if we omitted or changed
them through inadvertence. This abuse of words consists
either in not connecting ideas with the whole or in connecting
them with an imperfect one, of which a part is empty and
abides so to speak in blank ; and in these two cases there is a
certain void and surd in the thought which is filled only
by the name. Or, finally, the defect is in attaching to the
word different ideas, whether we are uncertain which should
be chosen, which makes the idea obscure as well as when a
part of it is surd ; or whether we select them by turns, and
avail ourselves sometimes of one, sometimes of the other as
the sense of the same word in one and the same course of
reasoning in a way capable of causing error, without consider
ing that the ideas do not agree. Thus the uncertain thought
is either void and without idea, or fluctuates between several
ideas. This does harm whether l we wish to designate some
definite thing or whether we wish to give a word a certain
sense corresponding either to that of which we have already
availed ourselves, or to that which others have used, above
all in ordinary language, common to all, or to the artisans.
And from this arise an infinite number of vague and vain dis
putes in conversation, in lecture-rooms, and in books, which we
1 Erdmann and Jacques omit: " soit qu'on veuille designer quelque chose
determiuee," the reading of Gerhardt. — TR.
CH. xxix] ON HUMAN UNDERSTANDING 271
may sometimes avoid by distinctions, but which most fre
quently serve only to confuse the more, by putting in the
place of a vague and obscure term other terms still more
vague and obscure, as those often are which the philosophers
employ in their distinctions, without having good definitions
of them.]
§ 12. Ph. If there is any other confusion in ideas, than this
which has a secret relation to names, this at least casts more
disorder than any other into the thoughts and discourse of
men.
Th. [I agree, but most frequently some notion of the thing
and the purpose which we have in availing ourselves of
the name is mixed with it ; as, for example, when we speak
of the church, many have in view a government, while others
think of the truth of the doctrine.]
Ph. The way to prevent this confusion is constantly to
apply the same name to a certain mass of simple ideas united
in a fixed number and into a determined order. But as that
suits neither the laziness nor the vanity of men, and as it can
be used only in the discovary and the defence of the truth,
which is not always the end they propose to themselves, such
precision is one of the things that is rather to be wished than
hoped for. The vague application of names to ideas inde
terminate, variable, and almost wholly empty (in the surd
thoughts) is on one side a covering of our ignorance and
on the other a confusing and embarrassing of others, which
passes as true learning arid as a mark of superiority in point
of knowledge.
Th. [The affectation of elegance and wit has further con
tributed much to this intricacy of language ; for in order to
express thoughts beautifully and agreeably we make no diffi
culty of giving words in a tropical manner a sense different
from the ordinary, sometimes more general or more limited,
which is called synecdoche., sometimes transferred according to
the relations of things whose names we change, either by
concurrence in metonymy, or by comparison in metaphor, not
to speak of iron//, which makes use of a term in a sense
directly opposite to its real meaning. Thus these changes are
named when recognized ; but they are recognized only rarely.
And in this indeterminateness of language, in which there is
272 LEIBNITZ'S CRITIQUE OF LOCKE [HK. n
lacking a kind of law which regulates the meaning of words,
as there is something in the title of the digests of the Roman
Law, De Verborum Siynificationibus, persons the most judic
ious, when they write for ordinary readers, would be deprived
of that which gives charm and force to their expression if
they should confine themselves rigorously to the fixed mean
ings of terms. They need only take care that their variation
does not cause any error or false reasoning to spring up. The
distinction of the ancients between the exoteric,1 i.e. popular,
and the acroamatic l mode of writing, which belongs to those
who are occupied in the discovery of truth, has place here.
And if any one wished to write in mathematical fashion in
metaphysics or ethics, nothing would prevent him from so
doing with rigor. Some have professed to do this, and we
have a promise of mathematical demonstrations outside of
mathematics ; but it is very rare that they have been success
ful. This is, I believe, because they are disgusted with the
trouble it is necessary to take for a small number of readers
where they could ask as in Persius : Quis leget haec, and
reply : Vel duo vel nemo.12 I believe, however, that if they
would undertake it in the proper way they would not be
likely to repent it. And I have been tempted to try it.]
§ 13. Ph. You will agree with me, however, that complex
ideas may be very clear and distinct in one aspect, and very
obscure and confused in another.
Th. [There is no reason to doubt it ; for example, we have
very distinct ideas of a good part of the solid visible parts
of the human body, but we have but few of the liquids which
enter therein.]
Ph. If a man speaks of a figure of a thousand sides, the
i Of. Leibnitz, De Stilo philos. Nizolii, Gerhardt, Vol. 4, p. 146 ; Erdmann,
p. 63. " Acroamatic " (ante, p. 42), from a/cp6a^a, anything heard, the verb
iicpoao-flai, the regular word for hearing or attending lectures, the adjective
a/cpoa/u-ariKo?, designed for hearing only, and, when used of the doctrines of
philosophers, meaning the esoteric, i.e. the doctrines in their most rigorous
and exact scientific form, their custom being to give these orally to their
pupils, while treating them in a more popular, exoteric manner in their writ
ings. Such was the method of Plato and of Aristotle, one of whose works is
called 4>v<r<.Kr) d*cp6a<ri9. Schaarschmidt refers to Bernays, Die Dialoge d. Aris-
totles, p. 30 sq. Berlin, 1863, and Madvig, Excursus VII. to his edition of
Cicero's De Finibus. — TB.
2,Saf. 1, lines 2, 3. — TR.
CH. xxix] ON HUMAN UNDERSTANDING 273
idea of this figure may be very obscure in his mind, although
that of the number may be very distinct therein.
Th. [This example is not in point here ; a regular polygon
of a thousand sides is known as distinctly as the millenary
number, because we may discover and demonstrate all kinds
of truth.]
Ph. But we do not have a precise idea of a figure of
a thousand sides, so that we can distinguish it from another,
which has only nine hundred ninety-nine.
Th. [This example shows that you here confound the idea
with the image. If any one places before me a regular poly
gon, sight and imagination cannot make me comprehend the
millenary therein ; I have only a confused idea both of the
figure and of its number, until I distinguish the number by
counting. But having found it, I know very well the nature
and the properties of the proposed polygon, as far as they
are those of the chiliagon, and consequently I have this idea
of it ; but I cannot have the image of a chiliagon, and it would
be necessary to have senses and imagination more exquisite
and better exercised in order to distinguish it thereby from
a polygon which had one side less. But the knowledge of
figures no more than that of numbers depends upon the imag
ination, although it is of service therein ; and a mathematician
can know exactly the nature of a nonagon and a decagon,
because he has the means of making and examining them,
though he could not discern them at sight. It is true that a
workman or an engineer, who does not perhaps know their
nature sufficiently, can have this advantage beyond a great
geometer that he can discern them by sight only without
measuring them, as there are some street-porters1 (faquins) or
pedlers, who will state the weight of what they are to carry
within a pound, in which respect they will surpass the most
skilful statistician in the world. It is true that 2 this empiri
cal knowledge acquired by a long practice may be very useful
for prompt action, such as an engineer very often needs to
perform because of the danger to which he is exposed in
delaying. But this dear image or this feeling which we may
1 Erdmann and Jacques omit: " faquins on," the reading of Gerhardt. — TR.
2 Erdmann and Jacques omit: " II est vray que," the reading of Gerhardt.
-Tit.
T
274 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
have of a regular decagon or of a weight of ninety-nine pounds
consists only in a confused idea, since it is of no avail in dis
covering the nature and properties of this weight or of this
regular decagon, which demands a distinct idea. And this
example conduces to the better understanding of the differ
ence of ideas, or rather that of the idea and the image.]
§ 15. l Ph. Another example : We are led to believe that we
have a positive and complete idea of eternity, which is as
much as to say that there is no part of that duration which
is not clearly known in our idea ; but, however great may be
the duration that is represented, as it is a question of an
extension without limits, there always remains a part of the
idea beyond what is represented which continues obscure and
undetermined; and thence it comes that, in discussions and
reasonings concerning eternity or any other infinite, we are
apt to involve ourselves in manifest absurdities.
Tli. [This example does not appear to me to square with
your design either; but it is very appropriate to mine, which
is to disabuse you of your notions on this point. For
the same confusion of the image with the idea reigns here.
We have a complete or just idea of eternity, since we have a
definition of it, although we have no image of it. But the
idea of the infinite is not formed by the composition of parts,
and the errors which we meet in reasoning upon the infinite
do not arise from the defect of the image.2]
§ 16. 3 Ph. But is it not true that when we speak of the
infinite divisibility of matter, although we have clear ideas of
the division, we have only very obscure and very confused
ideas of the parts ? For I ask whether a man taking the
1 Erdmann and Jacques have § 25. Gerhardt and Locke, Philos. Works,
Vol. 1, p. 505 (Bolm's ed.), have § 15. — TR.
a The difficulties and errors in the discussion of the infinite arise not " from
the defect of the image" but from the attempt to imagine or picture that
which can only be thought. We can think the infinite and absolute, but we
cannot form an adequate image or picture of it. The " confusion of the image
with the idea," which Leibnitz here speaks of, is one of the causes vitiating
much of the "reasoning upon the infinite" in the history of thought, and
lying at the basis of all theories, like those of Hamilton, Mansel, and Spencer,
which maintain the impossibility on man's part of a knowledge of the infinite.
Of. John Caird, An Introduction to the Philos. of Religion, p. 36. New York :
Marmillan & Co., 1880. — TR.
3 So Gerhardt and Locke, Philos. Works (Bolm's ed.), Vol. 1, p. 505; Erd-
maun has § 18 ; Jacques § 30. — TR.
CH. xxx] ON HUMAN UNDERSTANDING 275
smallest atom of dust he ever saw has any distinct idea
of the difference between the one hundred thousandth1 and
the millionth part of this atom ?
Th. It is the same qui pro quo of the image for the idea,
which I am astonished to see so confused. The possession of
an image of so great a smallness is not at all the question,
It is impossible according to the present constitution of
our body, and if we could have it, it would be much the same
as that of those things which now appear to us apperceptible ;
but in compensation what is now the object of our imagination
would escape us and become too great to be imagined. Size
has no images in itself, and those which it has depend only
upon comparison with the organs and other objects, and it is
useless here to employ imagination. Thus it appears by all
that you, sir, have said to me here that you are ingenious
in devising difficulties without reason, in demanding more
than is necessary.]
CHAPTER XXX
OF REAL AND FANTASTICAL IDEAS
§ 1. Ph. Ideas in relation to things are real or fantastical,
adequate or inadequate, true or false. By real ideas I under
stand those which have a foundation in nature, and which are
conformed to a real being, to the existence of things, or to
their archetypes ; otherwise they are fantastic or chimerical.
Tli. [There is a little obscurity in this explication. The
idea may have a foundation in nature, without being con
formed to this foundation, as when we maintain that the per
ceptions we have of color arid heat do not resemble any orig
inal or archetype. An idea is also real when it is possible,
although no existing being corresponds thereto. Otherwise
if all the individuals of a species were lost, the idea of the
species would become chimerical.]
§ 2. Ph. Simple ideas are all real, for, although [according
to many] whiteness and coldness are no more in snow than is
pain, yet their ideas are in us as effects of powers connected
1 Erdmanu and Jacques read : " la 10,000me et la lOOOme." — TR.
276 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
with external things, and these constant effects serve us in
distinguishing things as much as if they were exact images of
that which exists in the things themselves.
Tli. [I have examined this point above : but it appears
thereby that you do not always demand a conformity to an
archetype, and, according to the opinion (which, however, I do
not approve) of those who think that God has arbitrarily
assigned us ideas, destined to mark the qualities of objects
without any resemblance or even natural relation, there would
be also in that case less conformity between our ideas and
the archetypes than there is between the words which we use
by institution in language and the ideas, or the things them
selves. ]
§ 3. Ph. The mind is passive as regards its simple ideas;
but the combinations it makes of them to form complex ideas,
where many simple ideas are comprised under one and the
same name, have somewhat of the volitional element ; for one
man admits into the complex ideas he has of gold or of
justice simple ideas which another does not admit.
Th. [The mind is, however, active in reference to simple
ideas when it detaches them one from another to consider
them separately, — an act which is voluntary as well as the
combination of many ideas ; whether it is done to call atten
tion to a complex idea resulting therein, or whether it is the
purpose to comprehend them under the name given to the
combination. And the mind cannot be deceived therein pro
vided it does not unite incompatible ideas and provided this
name is still virginal, so to speak, that is to say, a name to
which some notion has not already been attached, which might
cause confusion with that which is newly attached thereto, and
make arise either impossible notions by joining together what
cannot take place, or notions superfluous and containing some
obreption,1 by joining ideas, one of which may and ought to
be derived from the other by demonstration.]
§ 4. Ph. Mixed modes and relations having no other reality
than that which they have in men's minds, all that is requisite
to make these sorts of ideas real is the possibility of existence
or of compatibility together.
Th. [Relations have a reality dependent upon the mind
1 I.e. Concealment of the truth. — TB.
CH. xxx] ON HUMAN UNDERSTANDING 277
like truths ; but not the mind of men, since there is a supreme
intelligence which determines them all for all time. Mixed
modes, which are distinct from relations, may be real acci
dents. But be they dependent or not dependent upon the
mind, it suffices for the reality of their ideas that these modes
be possible or, what is the same thing, distinctly intelligible.
And for this result it is necessary that their ingredients be
compossible, i.e. capable of existing together.]
§ 5. Ph. But the complex ideas of substances, as they are
all formed in relation to things existing outside of us, and
as representative of substances such as really exist, are real
only so far as they are combinations of simple ideas really
both united and coexisting in things coexisting without us.
On the contrary those are chimerical l which are composed of
such collections of simple ideas as have never been really
united and found together in any substance ; like those which
form a centaur, a body resembling gold, save in weight, and
lighter than water, a body similar in relation to the senses,
but endowed with perception, voluntary movement, etc.
Th. [If I take in this manner the terms real and chimeri
cal otherwise in relation to the ideas of the modes than in
relation to those which form a substance, I do not see what
common notion in each case you give to real or chimerical
ideas ; for the modes are real to you when they are possible,
and substances have real ideas with you only when they
are existent. But in desiring to tally with existence, we
can determine but little whether an idea is chimerical or
not, because what is possible, although not found in our
place or time, may have existed formerly or will perhaps
some day exist, or may indeed be found already present in
another world, or even in ours without our knowing it, like
the idea which Democritus had of the Milky Way2 which the
telescopes have verified : so that it seems better to say that
possible ideas only become chimerical when we attach to them
without foundation the idea of effective existence, as those do
who promise themselves the philosopher's stone or, as those
1 Locke has: "fantastical," Philos. Works, Vol. 1, p. 510 (Bohn's ed.)- —
TR.
2 Cf. Aristotle, Meteorologica, Bk. I., chap. 8, 345«, 25: "The Milky Way
is the light of certain stars." Zeller, Die Philos. d. Griech., 3d ed., Vol. 1,
p. 724, note 1 ; 5th ed., 1892, I. 2 [Vol. 2] , p. 897, note 8. — TR.
278 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
would do who should believe that there had been a nation
of centaurs. Otherwise in not regulating ourselves by exist
ence we shall deviate unnecessarily from the received language,
which does not allow us to say that he who speaks in winter
of roses or pinks speaks of a chimera, unless he imagines he is
able to find them in his garden, as the story is told of Albert
the Great1 or of some other pretended Magician.]
CHAPTER XXXI
OF ADEQUATE2 AND INADEQUATE IDEAS
§ 1. Ph. Real ideas are complete when they represent per
fectly the originals whence the mind supposes them to be
taken, which they represent, and to which it refers them.
Incomplete ideas represent only a part of these originals.
§ 2. All our simple ideas are complete. The idea of white
ness or of sweetness, which is noticed in sugar, is complete,
because it suffices for this, — that it corresponds entirely to the
powers that God has put into this body to produce these
sensations.
Th. [I see, sir, that you call complete or incomplete ideas
those which your favorite author calls idece adwqiuitoe ant
inadcequatw; you might call them perfect or imperfect. I
have sometimes denned idea adwquata (a perfect idea} as that
which is so distinct that all its ingredients are distinct, and
such is nearly the idea of a number. But when an idea is
distinct and contains the definition or the reciprocal marks
of the object, it may be inadcequata or imperfect, viz. : when
i Albertus Magnus, 1193-1280. Schaarschmidt states that "like many other
scholars of those dark centuries (Michael Scotus, Roger Bacon, etc.) he was
suspected of Magic," and adds that " Trithemius in particular, who, moreover,
takes the philosopher into his protection, gives an account thereof in his An-
nftles Hirsaugienses, Vol. 2, p. 40. Naude in his Apologie des Grands Hommes
Soupr;onn€s de Mayie, chap. 18, Bayle in his Dictionary, see under Albert
Le Grand, and Brucker. Hist. Philosophise, 3, 793 sq., have likewise defended
him." On his life and philosophy, cf. Erdmann, Grundriss d. Gesch. d.
Philos. §§ 199-202, Vol. 1, pp. .350 sq., and English translation of same; also
Stockl, Gexch. d. Philos. d. Mittelalters, Vol. 2, pp. 352 sq., §§ 101-119. — TR.
2 Locke's title; the French might be rendered " complete and incomplete,"
«ts in the text. — TR.
CH. xxxi] ON HUMAN UNDERSTANDING 279
these marks or these ingredients are not also all distinctly
known ; for example, gold is a metal which resists the cupel
and aqua fortis ; it is a distinct idea, for it gives the marks
or the deliiiition of gold; but it is not perfect for the nature
of cupellation and the working of aqua fortis is not sufficiently
known to us. Whence it conies that, when there is only an
imperfect idea, the same subject is susceptible of many defini-
tions independent the one of the other, so that we cannot
always derive one from the other nor see beforehand that they
must belong to one and the same subject, and then experience
alone teaches us that they all belong to it at once. Thus gold
may still be defined as the heaviest of our bodies, or the most
malleable, without speaking of other definitions which might
be invented. But we shall be able to see why it belongs
to the heaviest of metals to resist these two tests of the assay-
ers only when men shall have penetrated farther into the
nature of things ; whilst in geometry, where we have perfect
ideas, the case is different, for we can prove that the sec
tions of the cone and of the cylinder, made by a plane, are the
same, viz. ellipses, and this cannot be unknown to us, if we
take notice of it, because the notions we have of them are
perfect. With me the division of ideas into perfect and im
perfect is only a sub-division of distinct ideas, and it appears
to me that only the confused ideas, like that we have of sweet
ness, of which you, sir, speak, deserve this name ; for although
they express the power which produces the sensation, they
do not express it wholly, or at least we cannot know this, for
if we comprehended what is in this idea of sweetness we have
we could judge whether it is sufficient as a rational expression
of all that experience causes us to notice therein.]
§ 3. Ph. From simple ideas let us come to the complex;
they are either of modes or of substances. Those of modes
are the voluntary collections of simple ideas which the mind
puts together without regard to certain archetypes or real and
actually existing models ; they are complete and cannot be
otherwise, because not being copies but archetypes, which the
mind forms in order to avail itself of them in ranking things
under certain denominations, they can lack nothing, because
each includes such a combination of ideas as the mind has
desired to form, and consequently such perfection as it had
280 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
planned to give thereto, and we cannot conceive that the
understanding of any one can have a more complete or more
perfect idea of a triangle than that of a figure of three sides
and three angles. He who put together the ideas of danger,
of execution, of the trouble that fear produces, of a calm con
sideration of what it would be reasonable to do, and of an
actual application to its execution without being frightened
by the danger, formed the idea of courage, and had what he
desired, viz. : a complete idea conformed to his good pleasure.
It is otherwise in our ideas of substances in which we main
tain that which really exists.
Th. [The idea of triangle or of courage has its archetype in
the possibility of things as well as the idea of gold. And it is
a matter of indifference, so far as the nature of the idea
is concerned, whether it was invented in advance of experi
ence, or whether it was retained after the perception of a
combination which nature had made. Combination also,
which produces the modes, is not wholly voluntary or arbi
trary, for we can put together what is incompatible, as those
do who invent machines for perpetual motion, while others
can invent those which are good and practicable which have
no other archetypes with us than the idea of the inventor
which has as its archetype the possibility of things or the
divine idea. Now these machines are substances. We can
also invent impossible modes, as when we maintain the
parallelism of parabolas, by imagining that we can find two
parabolas parallel to each other, like two straight lines or
two circles. An idea, then, whether it be that of a mode, or
that of a substance, may be complete or incomplete according
as we understand well or ill the partial ideas which form the
total idea : and it is a mark of a perfect idea when it makes
known perfectly the possibility of the object.]
CH. xxxin] ON HUMAN UNDERSTANDING 281
CHAPTER XXXII
OF TRUE AND FALSE IDEAS
§ 1. Ph. As truth1 or falsehood belongs only to proposi
tions,2 it follows that when ideas are termed true or false
there is some tacit proposition or affirmation; § 3. or a tacit
assumption of their conformity to something, § 5. above all
with what others designate by this name (as when they speak
of justice) item to what really exists (as man exists but not
the centaur) item to the essence, upon which depend the prop
erties of the thing ; and in this sense our ordinary ideas of
substances are false when we think of certain substantial
forms. Besides, ideas deserve rather to be called accurate
or faulty, than true or false.
Th. I believe that true or false ideas might be so under
stood, but as these different senses do not agree between them
selves and cannot be conveniently ranked under a common
notion, I prefer to call the ideas true or false in relation to
another tacit affirmation which they all include, which is that
of possibility. Thus possible ideas are true, impossible false.~\
CHAPTER XXXIII
OF THE ASSOCIATION OF IDEAS
§ 1. Ph. We often notice something odd in the reasonings
of people, and everybody is subject to this. § 2. It is not
alone obstinacy or self-love ; for often people who are well
disposed are guilty of this fault. It does not indeed suffice to
1 Cf. New Essays, Bk. IV., chap. 5. — TB.
2 Cf. Aristotle De Anima, III. 6,430*, 27, and E. Wallace, Aristotle's Psychol
ogy in Greek and English, with Introduction and Notes, pp. 160, 161, Cam
bridge: University Press, 1882; also De Interpret. 1, 16a, 12, and E. Wallace,
Outlines of the Philos. of Aristotle, 3d ed., § 11, p. 27. For Leibnitz, the true
is the thinkable, i.e. that which is free from contradiction in itself and of
other truth. Thought-necessity is his criterion of possibility and of truth. —
TB.
282 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
attribute it to education and to prejudice. § 4. It is rather
a kind of madness, and we should be foolish if we should
always act thus. § 5. This fault arises from a non-natural
connection of ideas, which has its origin in chance or custom.
§ 6. Inclination and interest enter into it. Certain tracts of
the repeated course of animal spirits become beaten roads ;
when we know l a certain air, we find it as soon as we begin
it. § 7. Thence arise the sympathies or antipathies which
are not born with us. A child has eaten too much honey and
has been surfeited by it, and then having become a full-grown
man, he cannot hear the name honey without a rising of the
stomach. § 8. Children are very susceptible to these impres
sions, and it is well to be careful of them. § 9. This irregu
lar association of ideas has a great influence in all our actions
and passions natural and moral. § 10. Darkness revives the
idea of ghosts in children because of the stories told them
about them. § 11. You do not think of a man whom you
hate without thinking of the evil he has done or may do.
§ 12. You shun the room in which you have seen a friend die.
§ 13. A mother who has lost a very dear child sometimes
loses with it all her joy, until time effaces the impression
of this idea, which sometimes never2 happens. § 14. A man
perfectly cured of madness by an extremely painful operation
acknowledged all his life his obligation to the one who per
formed this operation ; but it was impossible for him to
endure the sight of the operator. § 15. Some hate books all
their life because of the bad treatment they received in school.
Some one having once gotten the upper hand of another upon
some occasion keeps it always. § 16. A man was found
who had learned to dance finely, but could not execute the
dance unless there was in the room a trunk like the one
which had been in the room where he had learned. § 17.
The same non-natural bond is found in the intellectual habits;
you bind matter to being, as if there were nothing immaterial.
§ 18. The sectarian party in philosophy, religion, and the
state is attached to its opinions.
Tli. [This remark is important and wholly to my taste, and
can be fortified by an infinite number of examples. Descartes
1 Gerhardt reads: <!sait"; Erdmann and Jacques: "suit," follow. — TR.
2 Gerhardt reads: " jamais " ; Erdmann and Jacques: " pas." — TR.
CH. xxxin] ON HUMAN UNDERSTANDING 283
having had in his youth some affection for a squint-eyed per
son could not prevent himself from having all his life an incli
nation towards those who had this defect. Hobbes, another
great philosopher, could not (they say) remain alone in a
dark place, without having his mind frightened by images of
ghosts, although he did not believe in them, this impression
having remained from the stories told to children. Many
persons well informed and sensible, and who are decidedly
superior to superstition, cannot bring themselves to be thir
teen at a repast without being extremely disconcerted, having
sometime been impressed by the fancy that one of them must
die during the year. ' There was a gentleman who, having
been injured, perhaps in his infancy, by a badly fastened pin,
could not see one in this condition without being ready to fall
into a swoon. A prime minister, who bore in the court of his
master the name of President, was offended by the title of the
book of Ottavio Pisani, called Lycuryus, and wrote against this
book, because the author, in speaking of the officers of justice
whom he thought superfluous, had named also the Presidents,
and although this term in the person of this minister meant a
totally different thing, he had so attached the word to his
person that he was wounded in this word. And this is a case
of the most usual of the non -natural associations, capable of
misleading, as those of words to things, when indeed there is
any ambiguity. In order the better to understand the source
of the non-natural bond of ideas, you must consider what I
have already said above (Chap. 11, § 11 ]), in speaking of the
reasonings of animals, that man as well as the animal is
inclined to put together in his memory and imagination- what
he has observed united in his perceptions and experience. It
is in this that all the reasoning, if so it may be called, of
animals consists, and often that of men, so far as they are
empirical and govern themselves only by the senses and
examples, without examining whether the same reason still
has force. And as often the reasons are unknown to us, we must
have regard to the examples in proportion to their frequency,
for then the expectation or the reminiscence of one perception
1 Cf. ante, p. 145. Gerhardt has § 1 ; Erdmann and Jacques § 11 ; the latter
reference is the correct one, and has therefore been placed in the text of the
translation. — TR.
284 LEIBNITZ'S CRITIQUE OF LOCKE [BK. n
on the occasion1 of another perception which is ordinarily
connected therewith is reasonable; particularly when the
question is about taking precautions. But as the vehemence
of a very strong impression often produces as much effect
at once as the frequency and repetition of many moderate
impressions would be able to make in a long time, it happens
that this vehemence engraves upon the fancy an image as
profound and as vivid as long experience.2 Whence it comes
that a chance but violent impression unites in our imagination
and memory two ideas, at that time together there,3 altogether
as strongly and durably and gives us the same inclination to
connect them and to attend to them one* after the other, as if a
long usage had verified the connection ; thus the same result
of association is found, although the same reason does not
exist. Authority, party,4 custom, produce also the same effect
as experience and reason, and it is not easy to deliver one's
self from these inclinations. But it would not be very
difficult to keep one's self from being deceived in these judg
ments, if men would attach themselves seriously enough to
the search for truth, or proceed methodically, when they
recognize that it is important to them to find it.]
1 Gerhardt reads: " d'une perception a 1'occasion," which Erdmann and
Jacques omit. — TR.
2 Erdmann and Jacques add : " auroit pu le faire," could have done. — TR.
3 Gerhardt reads: " qui y estoient ensemble alors, tout aussi fortement et
durablement; et nous donne," etc. Erdmann and Jacques, " qui de'ja y
e'taient ensemble, et nous donne," etc. — TR.
4 Erdmann and Jacques omit : " le parti." — TR.
NEW ESSAYS ON HUMAN UNDERSTANDING
BOOK III.-- WORDS
CHAPTER I
OF WORDS OR LANGUAGE IN GENERAL
§ 1. Ph. God having made man to be a social being, has not
only inspired him with the desire, and placed him under the
necessity of living with those of his species, but has given
him also the faculty of speech which is to be the great instru
ment and common bond of this society. Hence it is that
words arise, which serve to represent and also to explain
ideas.
Tli. [I rejoice to see that you are averse to the view of
Hobbes,1 who did not admit that man was made for society,
i Thomas Hobbes, 1588-1679, in bis De Give, 1642, and Leviathan, 1651,
maintained that man, being by nature a selfish and solitary animal, had no
natural impulse for society, and that social union sprang simply from fear
and from motives of gain, the natural condition being that of universal war.
Leibnitz maintains, in agreement with Aristotle and Hugo Grotius, 1583-1645,
that Nature herself has destined man for society in order not only that he
may the better and more easily realize his highest being, but that he may
realize it at all, such realization being impossible in isolation and solitude.
Cf. Aristotle, Polit. I., 2, 1253a, 2: on riav <f>v<rei ij TroAis e<jTt, /ecu on aV#pu>7ros $v<rei
7roAinKbj> £wov; HI., (}f 1278h, 19: 4>vo-et /u.eV etrnv a.vOpiano<; £<Zov TroAiTiKoV, 6ib KOI
/j.rjSei' Seo/xei'Oi TTJ? Trap' aAArjAioi' /3or)#e<.'a<r OVK e\arrov bpeyovrai rov ffv^v^ English trans
lation by B. Jowett, Vol. 1, pp. 4, 78, Oxford: Clarendon Press, 1885; also Eth.
NlC. IX., 9, 1169% 3 Sq., CSpeC. 16-19: Zrorrov 6' "t<™? <ai TO ^ovcinjv iroteZv TOV
/xoxapioi' * ouflel? -yap e'Aoir' ay ica.9' avrbv ra TTO.VT' e\eiv ayaOd ' TTO\LTLKOV yap 6 avQpunros
Kal av&v Tre^u/co?, I., 1, 1094h, 6 sq., English translation by F. H. Peters, pp. 307
sq., 3 ; cf. also Zeller, Philos. d. Griech., II., 2 [Vol. 4], pp. 680, 662, 3d ed., 1879.
Grotius, De Jure Belli et Pads, 1625, Preliminary Discourse, § 6: " Amongst
the things peculiar to man, is his desire of society, that is, a certain inclination
to live with those of his own kind, not in any manner whatever, but peace-
285
280 LEIBNITZ'S CRITIQUE OF LOCKE [UK. in
conceiving that he has been forced into it by necessity and by
the wickedness of those of his species. But he did not con
sider that the best men, free from all wickedness, united them
selves the better to obtain their purposes, as the birds flock
together the better to travel in company, and the beavers unite
in large numbers to make great dams, in which work a small
number of these animals could not succeed ; and these dams
are necessary to them, to provide reservoirs of water or little
lakes, in which they build their huts and catch the fish upon
which they feed. This then is the foundation of the society
of the animals which are adapted to it, and nowise the fear of
their kind, which is rarely found among animals.]
Ph. Very true, and it is the better to cultivate this society
that man by nature has his oryans so fashioned that they are
adapted to the formation of the articulate sounds which we
call words.
Th. [As for organs, monkeys have them apparently as suit
able as ours for the formation of words, but they do not take
the least step in this direction.1 Thus it must be that they
lack an invisible something. We must also consider that we
ably, and in a community regulated according to the best of his understand
ing, which disposition the Stoicks termed otKeiWi? " : quoted from English
translation with "all the large notes of Mr. J. Barbeyrac," etc., London:
Printed for W. Innys and R. Manby, and others, 1738. A French translation
by Jean Barbeyrac., professor of law at Groningen, "with the author's notes
which had not, yet appeared in French, and new notes by the translator,"
2 vols., 4to, Amsterdam, 1724; a later translation into English by Whewell,
3 vols., 8vo, Cambridge, 1853; a German translation in J. H. v. Kirchmann's
Philos. BibliotheJf, 3 vols., 12mo, Leipzig. 1879.
In the formation of society, language — A6yo?, rational speech — plays an
important part, serving as a special means of communication between men.
Cf. Aristotle, PolH. I., 2-18, 1253'' ; Grotins, De Jure Belli et Paris, Prelim.
Disc. § 7: "A man grown up . . . has besides an exquisite desire of society,
for the satisfaction of which he alone of all animals has received from nature
a peculiar instrument, viz. the use of speech." — TR.
1 Schaarschmidt states that "this earlier generally diffused view, that the
apes had organs of speech — an opinion still at the present day firmly held by
the negroes — has already been refuted by Peter Camper," 1722-1789, a dis
tinguished Dutch anatomist and naturalist, in his Natuurkundige Verhand-
elinr/en orer den Oranrf-Outan;/ an ccni'ie andere Anpsoortrn; cf. p. 147 *f].,
of the German translation by J. F. M. Herbell. Diisseldorf, 1791, 4to. The
most important of Camper's works bearing on comparative anatomy, trans
lated into French by H. C. Jansen, were published in (Eurres de P. Camper
qui ont pour objct r'histoire nattirellr>, la physiologic, ct V anatomic comparer.
Paris, 1803, 3 vols., 8vo. The piece referred to in this note is found in Vol. 1
of this ed. — TR.
en. i] OX HUMAN UNDERSTANDING 287
could speak, i.e. make ourselves understood by the sounds of
the mouth without forming articulate sounds, if we availed
ourselves of musical tones for this effect ; but more art would
be necessary to invent a language of tones, whilst that of
ivords may have been formed and perfected gradually by per
sons who found themselves in a state of natural simplicity.
There are, however, people like the Chinese, who by means of
tones and accents vary their words, of which they have only a
small number. Thus it was the opinion of Golius,1 a cele
brated mathematician and great linguist, that their language is
artificial, i.e. had been invented all at once by some clever man
in order to establish verbal intercourse between the large num
ber of different nations inhabiting this great country which
we call China, although this language may now be found
altered by long use.]
§ 2. Ph. [As orang-outangs and other monkeys have organs
without forming words, we can say that parrots and some
other birds have words without language], for we can train
these birds and many others to form sounds quite distinct ;
but they are nowise capable of language. Man only is in a
condition to avail himself of these sounds as signs of internal
conceptions, in order that thereby they may be manifested to
others.
Tit. [I believe in fact that apart from the desire of making
ourselves understood we should never have formed language ;
but being formed, it further serves man in reasoning within
himself, both by the means words give him of remembering
his abstract thoughts, and the benefit he finds in availing him
self in reasoning of characters and surd thoughts ; for he
would require too much time, if he were obliged to explain
everything and always to substitute definitions in the place of
terms.]
§ ,'>. Ph. But as the multiplication of words would produce
1 Jacob Gobi — Latin, Golius — 159(>-1(>(>7, an eminent Dutch orientalist,
who distinguished himself at Leyden University in classics, mathematics, and
philosophy, was a pupil of Erpenius in Arabic, and in 1(>24 succeeded him as
professor of Arabic at Leydeu. In l(j'29 he returned from Asia Minor and the
East, where he had spent four years, bringing with him a large and valuable
collection of Mss. which he placed in the library of the university. His prin
cipal work, still to-day esteemed, is the Lexicon Arabico-Latinum, 1(55;},
folio.— TR.
288 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
confusion in their use, if a distinct term were necessary to
designate each particular thing, language has been further
perfected by the use of general terms when they signify general
ideas.
Tli. [General terms serve not only for the perfection of
languages, but they are necessary even to their essential
constitution. For if by particular things we mean individual
things, it would be impossible to speak if there were only
proper names and not appellatives, i.e. if there were words
only for the individuals, since at every moment something
now presents itself (to the mind) when individuals, accidents,
and particularly acts, which are most frequently designated,
are in question. But if by particular things we understand
the lowest species {species infimce), besides the fact that it is
difficult very often to determine them, it is manifest that they
are already universals formed upon similitude. Then as the
question is only of a similitude more or less extended, accord
ing as we speak of genera or species, it is natural to indicate
every sort of similitude or agreement and consequently to
employ general terms of all degrees ; and indeed the most
general being less burdened with relation to the ideas or
essences they include, although they are more comprehensive
in relation to the individuals to which they apply, were very
often the easiest to form and are the most useful. Thus you
see that children and those who know only little of the lan
guage which they wish to speak, or of the matter of which
they speak, avail themselves of general terms as thing, plant,
animal, instead of employing the proper terms which they lack.
And it is certain that all proper or individual names were
originally appellative or general.1]
1 Leibnitz seems here to be in error in deciding from a logical or meta
physical point of view that language originated in or proceeded from general
terms and relations rather than in those which are individual. In the order
of experience the individual thing or relation is first, and first receives its
name either wholly arbitrarily or by convention, or by this in combination
with natural imitation or suggestion ; the generalizing process and its result,
the general name or term, comes afterwards. Children, it is true, use terms
of general import, but with no consciousness that they are general. Every
thing is for them individual, particular, separate and by itself until continued
observation and increasing knowledge enable them to detect similarities and
differences and to classify arid generalize accordingly. Then only do they,
strictly speaking, possess or use general terms. — TR.
CH. i] ON HUMAN UNDERSTANDING 289
§ 4. Ph. There are also words which men employ not to
signify an idea, but the lack or absence of a certain idea, as
nothing, ignorance, sterility.
Th. [I do not see why we could not say that there are
privative ideas, as there are negative truths, for the act of
denial is positive. I had already touched upon this.]
§ 5. Ph. Without disputing about this point, it will be more
useful to approach a little nearer the origin of all our notions
arid knowledge, to observe how the words employed to form
actions and notions wholly removed from the senses, derive
their origin from sensible ideas, whence they are transferred
to significations more abstruse.
Th. [The fact is our needs have compelled us to leave the
natural order of ideas, for this order would be the same for
angels, men, and all intelligences in general, and would have to
be followed by us, if we had no regard for our interests. It
has been necessary to attach thereto what the occasions and
accidents to which our species is subject have furnished us ;
and this order gives not the origin of the notions, but so to speak
the history of our discoveries.1^
Ph. [Very true, and it is the analysis of words which may
teach us by means of the names themselves this concatenation
which that of the notions cannot give by means of the reason,
which you have brought forward.] Thus the following words :
imagine, comprehend, to attach, conceive, instit, disgust, trouble,
tranquillity, etc., are all derived from the operations of sensible
things and applied to certain modes of thought. The word
spirit in its primary signification is breath,2 and angel signifies
a messenger. Whence we can conjecture what kind of notions
1 "The natural order of ideas," according to Leibnitz, proceeds from the
general to the particular, from the abstract to the concrete, while language
shows that "we have advanced from sense-impressions to abstract ideas,"
arid thus " expresses not the essence of our knowledge, but only the history of
its development. In a still broader sense the history of language is the history
of the development of the human spirit in general." — TR.
2 Cf. the Hebrew Pin (Spinoza, Trad. Theol. Polit., chap. 1, Opera, ed. Van
Vloten and Land, Vol. 1, p. 384; English translation by Elwes, Vol. 1, p. 19) ;
the Greek TTVMV.O. from wlv (Cremer, Bib. Theol. Lexicon of N. T. Greek, 2d
English from 2d German ed., p. 504, Edinburgh : T. and T. Clark, 1878, says
that as " the element of life " ..." in a physiological sense, we often find it
(< TTvevna.'} in profane Greek, especially in the poets and in later Greek; in a
psychological sense, as the element of human existence and personal life,
never") ; and the Latin spiritus from spirare. — TR.
U
LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
they had who spoke these first languages and how nature will
suggest unexpectedly to men the origin and the principle of all
their knowledge by the terms themselves.
Th. [I have already remarked to you that in the credo of
the Hottentots they called the Holy Spirit by a term which
signifies among them a breath of air benign and sweet.1 The
same is true as regards the majority of other words, and indeed
the fact is not always recognized because most frequently the
true etymologies are lost. A certain Dutchman, with little
regard for religion, abused this truth (that the terms theology,
ethics, arid metaphysics are taken originally from gross things)
in order to ridicule theology and the Christian faith in a little
Flemish dictionary, in which he gave to the terms definitions
or explications not such as usage demands, but such as the
original force of the words seemed to bear, and put upon them
a malicious interpretation ; and as he elsewhere had given
indications of impiety he is said to have been punished in the
Raspel-huys? It will, however, be well to consider this analogy
of sensible and non-sensible things which has served as the basis
of tropes : a matter that you will understand the better by con
sidering a very extended example such as is furnished by the
use of prepositions, like to, with, from, before, in, without, by, for,
upon, toivards (a, avec, de, devant, en, hors, par, pour, sur, vers),
which are all derived from place, from distance, and from
motion, and afterwards transferred to every sort of change,
order, sequence, difference, agreement. To (<Y) signifies
approach, as in the expression : I go to (&) Rome. But as in
order to attach anything we bring it near that to which we
wish to unite it, we say that one thing is attached to (d)
another. And further, as there is, so to speak, an immaterial
attachment, when one thing follows the other from moral
reasons ; we say that what follows the movements and voli
tions of any one belongs to (d) that person or adheres to him
as if it gave signs to this person to go near it or with it. A
1 Cf. Book I., chap. 3, § 8, Th. The Apostle's Creed, the Ten Command
ments, and the Lord's Prayer in the Hottentot language, as sent to Leibnitz
by N. Witsen, are given in Dutens, Leibnit. opera omnia, Vol. 6, Pt. 2, pp.
204-20(5. Schaarschmidt remarks that " this observation of both philosophers,
that the meaning of words has proceeded and still proceeds from the concrete
to the abstract, is the guide to sound etymology and word-explanation." — TR.
2 Erdmann and Jacques have: " Raspel-huyss." — TR.
CH. u] ON HUMAN UNDERSTANDING 291
body is with (avec) another when they are in the same place ;
but they say also that a thing is with (avec) that which is found
in the same time, in the same order, or part of an order, or
which concurs in one and the same act. When we come from
(de) any place, the place has been our object through the
sensible things it has furnished us, and it is still in our
memory, which is entirely filled with it; and thence it comes,
that the object is signified by the preposition of (de) as in the
expression, the question is of (de) that, they speak of (de)
that, i.e. as if it arose from it. And as what is included in
any place or in any whole is supported by and carried away
with it, the accidents are in the same way considered as in
(dans) the subject, sunt in subjecto, inhcerent subjecto. The
particle upon (sur) is also applied to the object ; they say he
is upon (sur) this matter, very much as a workman is upon
(sur) the wood or upon (sur) the stone, that he cuts or forms;
and as these analogies are extremely variable and do not de
pend on any determinate notions, it thence comes that
languages vary much in the use of these particles and cases
which the prepositions govern, or rather in which they are
found as things understood and virtually included.]
CHAPTER II
OX THE SIGNIFICATION' OF WORDS
§ 1. Ph. Now as words are employed by men as signs of
their ideas, we may ask in the first place how their words have
been determined ; and we find that it is not by any natural
connection existing between certain articulate sounds and cer
tain ideas (for in this case there would be only one language
among men), but by an arbitrary institution in virtue of which
a given word has been purposely made a sign of a given idea.1
1 For early discussions of the nature and origin of language, and the ques
tion whether words were given by nature or convention, cf. Plato, t'ruti/lus,
English translation by B. Jowett, The Dialogues of Plato, 2d ed., 1875, Vol. 2,
p. 203 *q. ; 3d ed., 1892, Vol. 1, p. 323 sq., New York : Macmillan & Co. ; Aristo
tle, De Interpret., 2, 16", 19 *q.; E. Wallace, Outlines of the Philos. of Aris
totle, 3d ed., § 11, p. 27. For modern discussions, cf. W. D. Whitney, Language
292 LEIBNITZ'S CRITIQUE OF LOCKE [BK. m
Th. [I know it has been customary to say in the schools
and almost everywhere else that the meanings of words are
arbitrary (ex institute) and it is true that they are not deter
mined by a natural necessity, but they are nevertheless
determined by reasons sometimes natural, in which chance has
some share, sometimes moral, where choice enters. There are
perhaps some artificial languages which are wholly of choice
and entirely arbitrary, as that of China is believed to have
been, or as those of George Dalgarno 1 and the late Mr. Wil-
kins,1 bishop of Chester. But those which are known to have
been coined from languages already known, are from choice
mixed with what there is of nature and chance in the lan
guages they suppose. Thus it is in the case of those languages
which thieves have coined in order to be understood only by
those of their gang, which the Germans call Jtothicelsch,2 the
and the Study of Language, Lect. XI., p. 395 sq. , 4th ed., New York, 1869;
B. Jowett, in his Introduction to Plato's Cratylus, op. cit., 2d ed., Vol. 2, p. 189
sq. ; 3d ed., Vol. 1, p. 281 sq. ; H. Steinthal, Einleitung in die Psychologic, mid
Sprachwissenschaft ; Herm. Paul, Principien der Sprachgeschichte, Halle,
1880; B. Delbriick, Einleitung in das Sprachstudium, Leipsic, 1880, 2d ed.,
1884. Leibnitz rightly points out that both nature and freedom of choice
share in the formation of language. " Nature furnishes to a certain extent
the material which the mind in its progressive self-absorption shapes within
certain limits arbitrarily ; and every human individual in the use of the
language already formed is himself still so situated as to be able up to a
certain point freely to appropriate and use that which is given." — TR.
1 George Dalgarno, c. 162(3-1(387, published at London in 1661, his Ars sig-
norum, vulgo character universalis et lingua philosophica. Qua poterunt,
homines dirersissimorum idiomatum, spatio duarum septimanarum , omnia
animi sua sensa (in rebus familiaribus) non minus intelligibiliter, sive scri-
bendo, sire loquendo, mutuo communicare, quam linguis propiis vernaculis,
from which Bishop John AVilkins, 1614-1672, derived the idea of his Essay
toioards a real character and a philosophical language ivith an alphabetical
dictionary. London, 1668. For Leibnitz's plan of a General Characteristic
(Characteristics Universalis — Specieuse generate) and the extent to which
he followed Dalgarno and Wilkins, cf. Trendelenburg's paper: Ueber Leibni-
zens Entwurf einer allgemeinen Charakteristik, in his Historische Beitrilge
zur Philos., Vol. 3, p. 1 sq., Berlin, 1867 ; cf. also Gerhardt, Die philos. Schrift.
v. G. W. Leibniz, Vol. 7, p. 3 sq. ; Vol. 3, p. 216; Dutens, Leibnit. opera omnia,
Vol. 6, p. 262. Dalgarno is credited with the invention of the first manual
alphabet. His works were reprinted at Edinburgh, 1834, 4to. — TR.
2 Cf. Ave Lallemant, Das deutsche Gauverthum, 4 vols., Leipzig, 1858-1862,
in which, says Schaarschmidt, " the so-called Rothwalseh, the artificial lan
guage of thieves in Germany, prominent already in the sixteenth and more so
in the seventeenth century, is treated with especial thoroughness of detail.
In this work it is shown that the Hebrew especially has contributed to the
Gaunersprache a strong word-contingent, while its grammar is conformed to
CH. n] ON HUMAN UNDERSTANDING 293
Italians Lingua Zerga,1 the French. Narquois, but which they
usually form upon (the basis of) the languages commonly
known to them, either by changing the received significations
of the words by means of metaphors, or by making new words
by means of a composition or derivation in their own fashion.
Languages are also formed through the intercourse of different
peoples, either by mingling indifferently neighboring lan
guages, or as most frequently happens, by taking the one as a
base which is mutilated and altered, mixed and corrupted by
neglecting and changing that which it observes, and even by
grafting thereupon new words. The Lingua Franca, which is
used in the commerce of the Mediterranean, is made from
the Italian, and no regard is paid to the rules of grammar.
An Armenian Dominican, with whom I conversed at Paris,
had himself made, or perhaps learned from his fellows, a kind
of Lingua Franca, made from Latin, which I found intelligible
enough, although it had neither case, nor tense, nor other
inflections, and he spoke it with ease, being accustomed to it.
Father Labbe,2 a French Jesuit, very learned, known by many
other works, has made a language of which Latin is the base,
which is easier and has less constraint than our Latin, but
which is more regular than the Lingua Franca. He has made
a book expressly of it. As for the languages which are found
made a long time ago, there are but few which are not greatly
the German. In Italy the Gaunersprache bears the name Gergo, which corre
sponds to the French Argot. To what extent in Leibnitz's time attention was
directed to the Rothwiilsch the romance literature shows ; but especially the
Gesichte Philanders von Sittewald," a remarkable work, in which, under the
name of Philander von Sittenwald, the author, Joh. Mich. Moscherosch, 1600-
1669, a German litterateur, whose true name was Kalbkopf , has given a series
of satirical pictures of the caprices and the vices of society in his time, and
which placed him among the best prose writers of his century. It was pub
lished at Strasburg, 1644-1650, 2 vols., 8vo. — TB.
1 Erdmann and Jacques read : " Gergo." — TR.
2 Philip Labbe, 1607-1667, a learned French chronologer, a man of vast
memory, astonishing erudition, and great mental activity; a voluminous
writer, and though gentle in personal character, a fierce and abusive contro
versialist. Leibnitz mentions him in a letter, July 15, 1709, to Geheimrath
von Ilgen; cf. Gerhardt, Leibniz, philos. Schrift., 7, 36: "nodi des P. Labbe'
(der die Lateinische mittelst einiger Veranderungen zur allgemeinen Sprach
machen wollen)." He was the author of Concordia chronologica, technica et
historica, 1656; but is chiefly known to-day by his work on Latin pronuncia
tion, Eniditss pronuntiationis catholici indices, enlarged by E. Leeds, and'
republished in London, 1751.— TR.
294 LEIBNITZ'S CRITIQUE OF LOCKE [UK. in
altered to-day. This is evident by comparing them with their
ancient books and monuments which remain. The old French
approached nearer the Provei^al and the Italian, and we see
the Theotisque 1 with the French or llomance rather (some
times called Lingua Romana rustica) as they were in the
ninth century after Jesus Christ in the forms of the oaths of
the sons of the Emperor Louis le Debonnaire, which Nithard,
their kinsman, has preserved for us." We find little elsewhere
of so old French, Italian, or Spanish. But for the Theotisque,
or ancient German, there is the gospel of Otffied,3 a monk of
1 Cf. Grimm, Deutsches Worterbuch, sub " Deutsch." — TB.
2 For the text of these famous oaths, taken at Strasburg, Feb. 14, 842, cf.
Nithard, c. 790-c. 858, Hist., written, at the command of Charles the Bald,
between 841 and 843, Bk. III., chap. 5, pp. 38, 39, ed. Pertz, and Pertz, Monu-
menta Germanise Historica, Vol. 2, pp. 6(55, 666, where they are preserved in the
old Romance — lingua Romana rustica — and old German — lingua Teotisca
— languages. Cf. also Dutens, Leibnitii opera omnia, Vol. 6, Pt. II., pp. 141-
144, where " utramque formulam (' jurarunt Ludoricus Romane, Carolus
Teutonice ') eodem significatu, conceptis verbis ex Nithardo exhibebimus
iuterlineariter colligatam, quia sibi verbotenus respondent, et ipso parallelismo
illustrantur." The best edition for the study of the old German part of the
oaths is in Karl Mullenhoff u. Wilhelm Scherer, Denkmdler deutscher Poesie
u. Prosa aus VIII-X1I Jahrh., Denkm. No. 67, 2 Ausg. Berlin, 1873; 3 Ann.
bearbeitet v. E. Steinmeyer. Vol. 2 contains notes summing up the best results
of critical study. Explanations of the old German text have also been made
by ,T. Grimm, 1785-1863, in his Kleinere Schriften, Vol. 6, pp. 403 sq., see
also Monumenta Germanise Historica, Vol. 2, pp. 465 sq. ; and by H. F.
Massmann, 1797-1874, in his Die kleinen Sprachdenkmale des VIII bis XII
Jahrh. Quedlinburg u. Leipzig, 1839. Fr. Ch. Diez, 1794-1876, "the real
founder of Scientific Romance philology and linguistics," in his Altromanische
tiprachdenkmaler, Bonn, 1846, has explained the Romance portion of the text,
and gives, op. cit. pp. 3-5, a good portion of the literature on this interesting
linguistic monument. The best textual notes on the Romance or old French
part of the oaths are in W. Foerster u. E. Koschwitz, Altfranzosisches Uebangs-
buch, Heilbroun, 1884; while the best facsimile of the whole fragment, both
French and German, is the Album of the Societe des anciens textes francais
(Les phis ancients monuments de la langue fran';aise), Paris, 1875. The old
Romance text, the earliest specimen of French in existence, with a modern
French translation, is found in Brachet, A Historical Grammar of the French
Tongue, 6th English, from 20th French ed., pp. 17, 18, Oxford: Clarendon
Press, 1884 ; while to these a Latin version is added for comparison in the
article on the "Latin Language" prope Jin., in the Encyclop. Brit., 9th ed.,
Vol. 14, pp. 340, 341 (American Reprint). — TR.
8 The gospel of Otfrid, usually called the Life of Christ, was written in the
South-Frankish dialect of the Old High German in 867 or 868, and dedicated
to King Louis the German. Editions of it were published by Matthias Flacius
Illyricus, 1520-1575, at Basle in 1571, 8vo, "a book as curious as rare," and
by Schilter-Scherz in the Thesaurus antiquitatum teutonicum, Vol. 1. Ulmae,
1727-1728, 3 vols., fol. These have now no critical worth, but merely an historical
en. ii J ON HUMAN UNDERSTANDING 295
Weissenburg of this same time, which Flacius has published
and which Sehilter1 wished to edit anew. The Saxons who
passed into Great Britain have left us books still more ancient.
They have a version or paraphrase of the beginning of Genesis
and of some other parts of the Sacred History, made by a
(Jyedmon whom Bede already mentions.2 But the most ancient
book, not only of the Germanic languages, but of all the lan
guages of Europe, except Greek and Latin, is that of the
gospel of the Goths of the Pontus Euxinus, known by the
name of Codex Argenteusf written in characters entirely pecu-
interest and value. Cf. H. Paul, Grundriss d. f/erm. PJiiloloyie, II, 214, Stras
burg, 1889—. It has also been edited by E. Th. Graff, Konigsberg, 1831, 4to, an
edition good in its day, but now antiquated ; and more recently by J. Kelle,
with grammar and glossary in 3 vols., Regensburg, 1856-1881 ; by P. Piper,
Paderborn, 1878, containing the fullest critical apparatus; and by Erdmann,
Halle. 1882, the most convenient. Piper has also published a student's edition,
Freiburg, 1884; and Kelle a translation, Christi Leben und Lekre besunyen
von Off rid, Prag. 1870. Cf. also W. Scherer, Gesch. d. deutschen Lit. 6th ed.,
pp. 48-51. Berlin, 1891; Eng. trans., from 3d Germ, ed., Vol. 1, pp. 44-4(5,
Xew York, Chas. Scribner's Sons, 1886. To Otfrid is due, for the most part,
the introduction into German poetry, in place of the earlier alliterative metre,
of the rhymed stanza imitated from that of the Latin Church hymns. — TR.
1 John Schilter, 1632-1705, a distinguished German jurisconsult and archae
ologist, Professor of Law at Strasburg, and author of the work referred to in
note 3, Thesaurus antiquitatuni teutonicum, which was edited, after Schilter's
death, by Job. Geor. Scherz, and is filled with documents of great value for
the civil and literary history of Germany at the time of the Carlovingians.
Schilter was led to linguistic studies through his legal and antiquarian investi
gations. Cf. Dutens, Leibnit. opera omnia, 6, Pt. II., p. 222, where Leibnitz
remarks: "I am told that Mr. Schilter, of Strasburg, is none too well, and
as he is an old man, I fear that his edition of Notger and Otfried will not
appear. . . . Mr. Schilter makes use, moreover, of the Gothic Gospels of
Ulh'las, of the Anglo-Saxon, and also of the Icelandic, as well as of other old
books and glossaries; for we must unite the different dialects of all the Teu
tonic peoples in order to explain the old books." — TR.
2 On Crtjdmon, died 680, <•/. Bede, Eedcs. Ilixt., Bk. IV., chap. 24, pp. 217-
220, 5th ed. (Bohifs Lib.), London: Geo. Bell and Sons, 1884; H. Morley, EIKJ-
lixh Writers, Bk. II., chap. 4, Vol. 2, p. 71 xq., London: Cassell and Co., 1888;
B. Ten Brink, Early Ena. Lit., trans, by H. M. Kennedy, pp. 39-48 and 371-
386, New York : Henry Holt & Co., 1884 ; S. A. Brooke, Jl'ist of Early En;/. Lit.,
pp. 275-1540, Xew York: Macmillan & Co., 1892. For the text of the poems
ascribed to him, cf. Benj. Thorpe, Csedmon's Metrical Paraphrase of Part of
the Holy Scripture in Analo-Saxon; with an Ena. Trans., Notex, and a Verbal
Index, London: 1832; C. W. M. Grein, Bibliothek der Angel-Sachsischen
Poenie, 1857, Vol. 1 ; new ed. by R. Wiilker, Vols. 1-3, 1883-1889, still in prog
ress ; the vol. containing Caedmon has not yet (1892) appeared; T. W. Hunt,
Cssdmon's Exodus and Daniel, Boston: Ginn & Co., 4th ed., 1889. — TR.
3 The Codex Argenteus — Silver Codex — so called because written in silver
and gold letters upon purple-stained vellum and bound in silver, as was the
296 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
liar, which was found in the ancient monastery of the Benedic
tines of Werden in Westphalia, and has been carried into
Sweden, where it is preserved, as with reason it should be,
with as much care as the original of the Pandects in Florence,
although this version wras made by the Eastern Goths and in a
dialect far removed from the Scandinavian German ; but it is
because they believe, with some probability, that the Goths
of the Pontus Euxinus came originally from Scandinavia, or
at least from the Baltic Sea. Now the language or the dialect
of these ancient Goths is very different from the modern
German, although it has the same linguistic basis. The
ancient Gallic was still more different, to judge by the lan
guage most nearly approaching the true Gallic, which is that
of the country of Wales, Cornwall, and Basse-Bretagne ; but
the Irish differs therefrom still more and shows us traces of a
Britannic, Gallic, and Germanic language, still more ancient.
But all these languages come from one source, and may be
case with costly Mss. in those days, originally consisted of 330 leaves con
taining the Gospels in the following order: Matt., John, Luke, Mark, trans
lated into the Gothic language, about the middle of the fourth century, by
Bishop Ulfilas (Vulfila), 311-383. Only 177 leaves now remain. Cf. F. L.
Stamm, Ulfilas, 1872, new ed. by M. Heyne, Paderborn, 1885, Einleitung, p. ix.
The Ms., like all existing Gothic Mss., seems to have been written in Italy
during the rule of the East Goths in the first half of the sixth century, and,
after many adventures, was at last carried in 1669 to Upsala, wheYe it now
is. It is one of the few sources of our knowledge of Gothic, and, as Ulfilas
was a fine scholar, and made his translation of the New Testament from the
Greek original, with frequent comparison of the Latin versions, it is of some
value in New Testament textual criticism. Editions of Ulfilas may be named
as follows: The two earlier, by H. C. v. d. Gabelentz and J. Loebe, 3 vols.,
Altenburg u. Leipzig, 1843-1846, and H. F. Massmann, Stuttgart, 1855-1856,
2 vols. 8vo, rest upon still older single editions with many faults. Cf.
H. Paul, Grundriss d. germ. Philologie, II, 69, Anm. 2. The critical editions
of A. Uppstrb'm : Codex Argenteus, Upsala, 1854-1855 ; Decem codicis arg.
rediviva folia, ib. 1857; Fragmenta gothica selecta, ib. 1861; Codices gothici
Ambrosiani, Stockh. u. Leipzig, 1864-1868, in whose work for the first time
was laid an entirely secure foundation for Gothic text-criticism, and upon
whom the later editions rest. Cf. H. Paul, op. cit.; and Stamm-Heyne,
Ulfilas, Einl. p. xi. The larger ed. of E. Bernhardt, Vulfila, oder die gotische
Sibel, Halle, 1875, is the best for comparison with the Greek ; while his smaller
ed., Die gotische Bibel des Vulfila, Halle, 1884, and that of Stamm-Heyne cited
above are the most convenient. The best introduction to Gothic in English is
J. Wright, A Primer of Gothic, London and New York, Macmillan & Co.,
1892. Cf. also W. Scherer, Gesch. d. deutschen Lit., 6th ed., pp. 33-36, Eng.
trans., Vol. 1, pp. 28-32; Waitz, Das Leben des Ulfilas, 1840; Krafft, Kirchen-
geschichte d. Deutschen Vdlker, Abth. 1, 1854, and article " Ulfilas," in Herzog,
ftealencyklopadie, Vol. 16, 1885. — TB.
CH. n] ON HUMAN UNDERSTANDING 297
taken as modifications of one and the same language, which
may be called the Keltic. Thus the ancients called both the
Germans and the Gauls Kelts ; and in going back farther in
order to understand the origin both of the Keltic and the
Latin and the Greek, which have many roots in common with
the Germanic or Keltic tongues, we may conjecture that this
fact arises from the common origin of all these peoples de
scended from the Scythians, who, having come from the Black
Sea, passed the Danube and the Vistula, and of whom one part
may have gone into Greece, the other have filled Germany and
the Gauls ; a consequence of the hypothesis which makes the
Europeans come from Asia. The Sarmatian (supposing it to
be the Sclavonic) has at least half its origin either Germanic
or common with the Germanic. The case appears to be some
what similar, indeed, in the Finnish language, which is that of
the most ancient Scandinavians, before the Germanic peoples,
i.e. the Danes, Swedes, and Norwegians, had taken possession
of the land which is the best and nearest the sea; and the
language of the Finns or of the northeast of our continent,
which is also that of the Lapps, extends from the German or
Norwegian Ocean even to the Caspian Sea (although inter
rupted by the Sclavic peoples which have been thrust in
between the two) and has some relation to the Hungarian,
having come from the countries which are now in part under
the Muscovites. But the Tartar language, which has filled the
northeast of Asia, with its variations, appears to have been that
of the Huns and Cumans as it is of the Uzbeks or Turkomans,
of the Kalmuks and of the Mongols. Now all these languages of
Scythia have many roots common among themselves and with
ours, and it is found that even the Arabic (under which the
Hebrew, the ancient Punic, the Chaldee, the Syriac, the Ethi-
opic of the Abyssinians are to be comprised) has so great a
number of them and an agreement so manifest with ours that
it cannot be attributed to chance alone, nor even to commerce
alone, but rather to the migrations of the peoples. So that
there is nothing in this to combat and not rather to favor the
view of the common origin of all nations, and of a primitive
root language.1 If the Hebrew or the Arabic approaches the
1 Leibnitz was the first who, from the point of view of a presentiment of the
kindred connection, first of the European, and then of tha remaining Ian-
298 LEIBNITZ'S CRITIQUE OF LOCKE [UK. in
nearest to it, it must be at least much changed, and the
German seems to have preserved more completely the natural
and (to use the language of Jacob Boehme) the Adamic;1 for
if we had the primitive language in its purity, or sufficiently
preserved to be recognizable, the reasons of the connections
whether natural or of an arbitrary institution would necessa
rily appear wise and worthy of the primitive author. But
supposing that our languages are derivative as regards their
foundation, they nevertheless have something primitive in
themselves which has arisen from them in relation to new
root words2 since formed among them by chance but upon
natural grounds. Those which signify the sounds of animals
or have come from them furnish examples. Such, for exam
ple, is the Latin coaxare attributed to the frogs, which has
some relation to couaqueti or quake n in German. Now it
guages, demanded and himself urged on the comparative study of languages,
and in this, as in so many other things, was far in advance of his time. For
his linguistic work, cf. Dutens, Leibnit. opera omnia, Vols. 5 and 6. — TR.
1 Jacob Boehme, 1575-16124, a celebrated theosophist, in whom Protestant
mysticism reached its highest point. He is called philosophus teutonicus, and
" in reality through him, for the first time in Germany, did philosophy come
forward with a characteristic stamp " ; Hegel, Vorlesung. it. d. Gesch. d. Philos.,
Vol. 3, p. 270, 2d ed., Berlin, 183-3. O. Ptieiderer, Religionsphilosophie, Vol.
1, p. 20, 2d ed., Berlin, 1883, says, "The theosophy of Boehme shows itself as
the direct forerunner of the metaphysic of Leibnitz, 1646-1716, Schelling, 1775-
1854, Baader, 17(55-1841, Schopenhauer, 1788-18(50, etc." For his philosophy,
etc., <-f. his Siimmtliche Werke, hrsg. v. K. W. Schiebler, Leipzig, 1831-47, 2d
ed., 1861 sq. ; also Hegel, op. cit., Vol. 3, pp. 270-21)7; Stoekl, Gesch. d. Philos.
d. Mittelalters, Vol. 3, pp. 569-608, §§ 122-128; O. Ptieiderer, op. Ht., Vol. 1,
pp. 15-23, Eng. trans., Vol. 1, pp. 13-23; B. Piinjer, Gesch. d. Christ. Relif/ions-
philos., 1880-83, Vol. 1, pp. 180-194; Eng. trans., Vol. 1, pp. 243-265, T. and
T. Clark, Edinburgh, 1887. Vaughan, Hours with the Mystics, Vol.2, pp. 79-125,
3d cd., London : 1879. According to Boehme, cf. Das dreyfache Leben, chap. 8,
2-4; Princ., 10, 8-12: Myst. Afctf/., chap. 15, 1-9, etc.; also Stoekl, op. cit., §§
125, 126, Vol. 3, pp. 586 sq. ; A'dam, who stands here in Leibnitz's text " as the
symbol and representative of the original unity of the race," and of its lan
guage, " was destired to propagate his race in angel-like purity without
endangering its integrity." Leibnitz, while acquainted with Boehme's writ
ings, made little use of them in his own thinking, and speaks thus of them in
a letter to Fr. S. Loeffler. Jan. 13, 1693, cf. Dutens, op. fit.. Vol. 5, p. 409 : " The
controversies over the opinions of Boehme I consider idle, and think that he
neither understood himself nor have others understood him." — TR.
2 Gerhardt's text reads: " Qui leur est survenu par rapport a des mots
radicaux nouveaux, forme's depuis chez elles." etc. Erdmann and Jacques
read: " qui leur est survenu par rapport a des mots radicaux et nouveaux
radicaux forme's depuis chez elles." etc.; i.e. new root words and new roots
since formed among them, etc. — TR.
CH. n] ON HUMAN UNDERSTANDING
seems that the noise of these animals is the primordial root of
other words of the German language. For as these animals
make much noise, the term is attributed to-day to idle talk and
to babblers, who are called quakeler in the diminutive form ;
but apparently this same word quaken was formerly under
stood in a good sense and signified all sorts of sounds made
with the mouth not even excepting speech. And as these
sounds or noises of animals are an evidence of life, and as we
know thereby before we see it that there is life there, quek in
old German has come to signify life or living, as may be
observed in the most ancient books, and there are also traces
of the same in the modern language, for Quecksilber is quick
silver (vif-argent), and erquicken is to strengthen, and, as it
were, to vivify or recreate after exhaustion or some great
labor. Certain weeds are called also in Low German Quaken,
alive so to speak and running, as they say in German, which
spread and propagate themselves easily in the fields to the
detriment of the grain ; and in English quickly means promptly
and in a wide-awake manner. Thus we may consider that as
regards these words the German language may pass as the
primitive, the ancients having no need to borrow elsewhere a
sound which is the imitation of that of the frogs. And there
are many others in which the same tiling appears. For it
seems that the ancient Germans, Kelts, and other peoples
allied to them have employed by a natural instinct the letter K
to signify a violent movement and a noise like that of this
letter.1 It appears in pew, flno, rinnen, riiren (fluere), rutir
(fluxion), the Rhine. Rhone, Roer (RJienus, Rhodanus, Erida-
uux. Rum), rauben (rapere, ravir), Radt (rota), radere (raser),
rausclien, a word difficult to translate into French ; it signifies
a noise like that which the wind or a passing animal stirs up
in the leaves or the trees, or is made by a trailing dress ;
reckken (to stretch with violence), whence it comes that reiclten
is to reach ; that der Rick signifies a long stick or perch useful
for suspending anything, in this kind of Plat-tiitsch or Low
Saxon which is (spoken) near Brunswick; that Rfge, Reihe,
1 f!f. Pluto, Crati/lu$,W: sq.; English Translation by B. Jowett; 2d ed.,
1875, Vol. 2, p. 25<» .SY-; 3:1 ed., 1892, Vol. 1, p. 381 sq., where the author has
already made an attempt, similar to that made here and many times before
by Leibnitz:, to fix the original significance of single letters in the formation
of words. — TR.
300 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
regida, regere, refer to length or a straight course ; and that
Reck has signified a thing or person very extended and long,
and in particular a giant, and then a powerful and rich man,
as it appears in the reich of the Germans and in the riche or
ricco of the Semi-Latins. In Spanish ricos hombres means the
nobles or chief men ; and this makes it plain at the same time
how metaphor, synecdoche, and metonymy have caused words
to pass from one signification to another without our being
able always to trace them. This noise and violent movement
is noticed also in Miss (rupture) with which the Latin rumpo,
the Greek pyywfu, the French arracher, the Italian straccio are
connected. Now as the letter R signifies naturally a violent
movement, the letter L designates a gentler one. Thus we see
that children and others who find the R too harsh or too diffi
cult to pronounce substitute for it the letter L, saying, for
example, mon levelend pele.1 This gentle movement appears in
leben (vivre — live), laben (conforter — comfort, faire vivre —
make live), lind, lenis, lentus (lent — slow), lieben (aimer —
love), lauffen (glisser promptement comme I'eau qui coule — to
glide quickly like flowing water), labi (glisser — to touch
lightly, labitur uncta vadis abies2), legen (mettre doucement — to
place gently), whence comes liegen (coucher — to lie down),
lage or laye (un lit, comme un lit de pierres — a bed, as a bed of
rocks), Lay-stein (pierre & couches, ardoise — slate), lego, icli lese
(je remasse ce qu'on a mis — I collect what has been invested,
it is the opposite of mettre — to place, and then je Us — I read,
and finally among the Greeks je parle — I speak3), Laub
(feuille — leaf), a thing easy to stir, to which are related also
lap, lid,4 lenken, luo, Xvw (solvo), leien5 (in Low-Saxon) to dis
solve, to melt like the snow, whence the Leine has its name,
a river of Hanover, which, rising in the mountainous coun
tries, is greatly enlarged by the melted snows ; not to speak
of an infinite number of other similar appellations, which prove
that there is something natural in the origin of words which
indicates a relation between things and the sounds and move-
i I.e. " Reverend pere." — TR. 2 Cf. Vergil, &n. 8, 91. — TR. _
3 Erdmann and Jacques omit: "Et puis je lis et enfin chez les Grecs je
parle," the reading of Gerhardt. — TR.
4 Gerhardt's reading; Erdmann and Jacques have "liel." — TR.
5 Gerhardt's reading; Erdmann and Jacques have "lien." — TR.
CH. n] ON HUMAN UNDERSTANDING 301
ments of the vocal organs ; and it is furthermore for that
reason that the letter L joined to other nouns makes their
diminutives with the Latins, the Semi-Latins, and the High
Germans. But it must not be pretended that this reason can
be noticed everywhere, for the lion, the lynx, the wolf, are
anything but gentle. But it may be attached to another acci
dent, the speed (lauf), which makes them feared or compels
flight ; as if the one who sees such an animal coming should
cry to the others: lauf (fuyez ! — fly!); besides by many acci
dents and changes the majority of words are very much
altered and diverted from their pronunciation and original
signification.
Ph. Yet an example would make it better understood.
Tli. Here is one plain enough and which comprehends man}
others. The word oail (eye) and its parentage may serve us.
To show it I will begin a little further back. A (the first
letter) followed by a little aspiration makes Ah, and as this
is an emission of the air which produces a sound clear enough
at its beginning and then vanishing, this sound naturally sig
nifies a light breath (spiritus lenis) when A and H are not
very strong. Thence it is that aw, aer, aura, laugh, halare,
haleine, ar/xo?, Athem, Odem (in German) have had their origin.
But as water is also a fluid and makes a noise, it has come
(it seems) that ah made rougher by doubling, i.e. aha or ahha,
has been taken as water. The Teutons and other Kelts, the
better to indicate the motion, have placed their W before
both. Thence wehen, Wind, vent, indicate the motion of the
air, and waten, vadum, water, motion of or in the water. But
to return to aha, it appears to be (as I have said) a kind of
root which means water. The Icelanders, who preserve some
what of the Scandinavian Teutonic, have lessened the aspira
tion of some by saying aa; others, who say Aken (meaning
Aix, Aquae grant1}, have increased it, as do also the Latins in
their aqua, and the Germans in certain places, who say ach
in compositions to indicate water, as when Schwarzach2 means
black water, Biberach water of the beavers. And instead of
Wiser or Weser they said Wiseraha in the old titles, and
Wisurach 2 among the ancient inhabitants, of which the Latins
1 I.e. Aquis Granum, Aix-la-Chapelle. — TR.
2 Gerhard t's reading; Erdrnann and Jacques read: " Schwartzach,"
" Wiser ach." — TR.
302 LEIBNITZ'S CRITIQUE OF LOCKE [BK. m
have made Visurgis, as from Her, llerach, they have made
Ilargus. From aqua, aigues, auue the French have finally
made eau, which they pronounce oo, in which there no longer
remains anything of its origin. Auwe, Auge with the Ger
mans is to-day a place which water often overflows, suitable
for pasturage, locus irriguus, pascuus; but more particularly
it signifies an island, as in the name of the monastery of
Reichenau (Augia dives), and many others. And this (process)
must have gone on among many of the Teutonic and Keltic
peoples, for thence it has come that everything which is, as
it were, isolated in a kind of plain has been called Auge or
Otige, oculus. Thus it is they name spots of oil upon water
among the Germans ; and among the Spaniards ojo is a hole.
But Auge, Ooge, oculus, occhio, etc., have been applied more
particularly to the oeil, as it were, pre-eminently, which makes
this isolated brilliant foramen in the countenance; and doubt
less the French oeil comes from it also, but its origin is not
at all recognizable, unless by the concatenation I have just
given ; and the o/x/x,a and oi//t? of the Greeks appear to come
from the same source. Oe or Oeland is an island among the
inhabitants of the North, and there is some trace of it in the
Hebrew, where *i^, Ai, is an island. Bochart l believed that
the Phoenicians derived the name which he thinks they gave
to the ^Egean Sea, full of islands, from the same source.
Augere, augmentation, comes also from Auue or Auge, i.e. from
the effusion of waters, as ooken, auken in old Saxon was to
augment ; and Augustus, when speaking as Emperor, was trans
lated by Ooker. The river of Brunswick, which comes from
the Hartz Mountains, and consequently is much subject to
sudden accretions, is called Ocker, formerly Ouacra. And I
mention in passing that the names of rivers, having ordinarily
1 Samuel Bochart, 1599-1667, an eminent French scholar and Protestant
theologian, a distinguished orientalist, and a man of profound erudition,
thoroughly familiar with all the principal oriental languages, including
Hebrew, Chaldaic, Syriac, and Arabic, and so enthusiastic in linguistic studies
that even when far advanced in years he desired to learn Ethiopia. His
favorite study was Phoenician, and though modest and candid he seeks to
derive all languages etymologic-ally " from the Hebrew or Phoenician," a pro
cedure which led him into many fanciful etymologies. Cf. Dutens, Leibnit.
opera omnia, Vol. 6, Pt. II., pp. 223, 226. His complete works were published
under the title, Sam. Bochart, opera omnia. Leyden, 1675, 2 vols. fol., 1692.
1712, 3 vols. fol. Leibnitz prized and often cited them. — TR.
en. n] ON HUMAN UNDERSTANDING 303
come from the farthest known antiquity, show best the old
language and the ancient inhabitants ; hence they deserve
particular investigation. And languages in general being the
most ancient monuments of peoples, before writing and the
arts, show best the origin of cognations and migrations.
Hence etymologies much extended would be curious and sig
nificant ; but it is necessary to unite the languages of many
peoples, and not to make too many leaps from one nation to
another far distant without having good verifications, in which,
process it is especially useful to have intervening peoples aa
guarantees. And in general credence must be given to ety
mologies only when there is a quantity of concurrent evidence ;
to do differently is to goropise.
Ph. To goropise? What does that mean?
Tli. It means that the strange and often ridiculous etymol
ogies of Goropius Becanus,1 a learned physician of the sixteenth
century, have passed into a proverb, although otherwise he
may not have been excessively wrong in claiming that the
German language, which he calls Cimbric, has as many, yes,
more, marks of a primitive character than the Hebrew itself.
I remember that the late Mr. Clauberg,2 an excellent philoso-
1 John Becan, 1518-1572, a Belgian physician and scholar, whose real name
was Van Gorp — Latinized as Goropius Becanus. He practised medicine for
some years at Antwerp, but finally gave himself wholly to the study of
antiquity, belles-lettres, and ancient languages. In a public lecture at Liege,
he attempted to demonstrate that the language of Adam was the Flemish or
Teutonic, a view which he set forth at length in his Origines Antwerpianse sive
G'inimeriorum Secceselana, etc., Antwerp, 1569, i'ol. ; and, as at that time he
considered the Netherlands to be the site of Paradise, to derive language in
general from the Low-German, which he calls the Cimbric, in his paper
Hermathena, Bk. II., p. 25 sq. Cf. Joannis Goropii Becani opera hactenus in
lurem non edita ; nempe, Hermathena, etc., Antwerp, 1580, fol. — TR.
2 John Clauberg, 1622-1665, a German philosopher of the Cartesian school,
who, first as a commentator merely and afterwards more independently,
introduced and expounded the philosophy of Descartes in the universities at
Herborn and Duisburg, where he was professor siiccessively of theology and
philosophy. He wrote a commentary on the Meditations of Descartes, and in
his own speculations anticipated much of the subsequent development of Car-
tesianism. In his De conjunctione aninife et corporis humcnii srriptum, he
maintained that bodily movements are antecedents only and not strictly causes
of mental action, a view similar to that of Malebranche. He proposed for
metaphysics the name Ontosophy or Ontology, a hint which Christian Wolf,
1679-1754, afterwards followed. Cf. Erdmann, Grund. d. Gesch. d. Philos.,
§§ 268, 4, 290, 4, Vol. 2, pp. 3,'i, 187, '«d ed., Berlin, 1878, and English trans, ad
loc. His Ontosophia, de cognitions Dei et nostri appeared at Muhlberg, 1687,
304 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
pher, has published a brief essay upon the sources of the
German language which makes one regret the loss of that
which he had promised upon this subject. I have myself
published some thoughts upon the subject, besides inducing
the late Gerard Meier,1 a theologian of Bremen, to work- upon
it, wrhich he did till death interrupted him. I hope, however,
that the public will yet one day profit from his labors as well
as from the similar labors of Mr. Schilter,2 a celebrated juris
consult at Strasburg, but who also has just died. It is certain
at least that the Teutonic language and antiquities enter into
the majority of the researches into European origins, customs,
and antiquities. And I wish that learned men would make
as much of them in the languages of the Wallachians, Bis-
cayans, Slavonians, Finns, Turks, Persians, Armenians, Geor
gians, and others, the better to discover the harmony which
would particularly be of service, as I have just said, in clearing
up the origin of nations.]
§ 2. Ph. [This design is important, but at present it is time
to leave the matter of ivords, and to return to their form, i.e. to
1 vol., 12mo; and his Opera philosophica at Amsterdam, 1691, 2 vols., 4to.
Leibnitz had a high regard for him, both as a philologist and philosopher,
and in one expression apparently places him even above Descartes; " Carte-
sius voluit qusedam emendare in physicis, displicet tamen audacia et fastns
nimius conjunctus cum stili obscuritate, confusione, maledicentia. Longe magis
mini probatus Claubergius, discipulus ejus, plenus, perspicuus, brevis, method-
icus." Cf. Otium Hanoveranum, ed. J. F. Feller, p. 181, Lipsiae, 1718; Dutens,
Leibnit. opera omnia, Vol. 6, Pt. I., p. 311. Leibnitz frequently mentions him
and his works, particularly the Meditationes et collectanea lingux Teutonic-SB,
Duisburgi, 1663, and the booklet Ars etitmolor/ica Teutonum; cf. Dutens,
op. cit., Vols. 5, p. 334; 6, Pt. II., pp. 28, 179, 220! In the Ars etymol. Teuton.
Clauberg puts it forth as a fundamental proposition that the German must be
explained as an original language. Cf. L. Neff., G. W. Leibniz als Sprach-
forscher nnd Etymoloye, Pt. I., p. 16 .<?<?., Heidelberg, 1870. — TR.
1 Gerard or Gerhard Meier or Meyer, who was incited by Leibnitz to the
study of German philology, and collected an abundance of select materials for
a Grammatica Germanica and Glossarium Savonicnm, but was prevented
from completing the work begun by his early and sudden death; cf. Eccard,
Collectanea etymologica, 2 vols., 8vo, Hannoverse, 1717, Einleitung, p. 52, and
Dutens, Leibnit. opera omnia, Vol. 6, Pt II., p. 145, note. Leibnitz states that
the Glossar. Saxon, was planned and undertaken with his encouragement, and
that it will contain much erudition; cf. Dutens, op. cit., Vols. 5, p. 115; 6, 114,
and note. For the correspondence between Meyer and Leibnitz, which exhib
its Meyer's method in his etymological work, cf. Dutens, op. cit., Vol. 6, Pt.
II., pp. 145-176. Leibnitz says : " His learning and character are esteemed by
all " — " Doctrina ejus, et virtus apud omnes in pretio habentur," Dutens, op.
cit., Vol. 5, p. 105. — TR. 2 Cf. ante, p. 295, note 1. — TR.
en. nj ON HUMAN UNDERSTANDING 305
the meaning which is common to the different languages.]
Now you will agree with me in the first place, sir, that when
one man speaks to another it is of his own ideas that he wishes
to give signs ; the words cannot be applied by him to things
which he does not know. And until a man has ideas of his
own he cannot suppose them to correspond to the qualities of
things or to the conceptions of another.
Tli. [It is true, however, that he intends very often to
indicate what others think rather than what he himself
thinks, as happens only too much in the case of the laity,
whose faith is implicit. But I admit that he always means
something general, however hollow and destitute of intelli
gence the thought may be ; and he takes pains at least to
arrange his words according to the custom of others, content
ing himself with the belief that their sense can be apprehended
at need. Thus he is sometimes only the interpreter (truclie-
man} of thoughts, or the bearer of the word of another, just as
a letter would be ; and indeed this is the case oftener than you
think.]
§ 3. Ph. [You are right in adding that he always means
something general, however idiotic it may be.] A child hav
ing noticed in what he hears called gold only a brilliant yellow
color, gives the name of gold to this same color wrhich he sees
in a peacock's tail; others will add great weight, fusibility,
malleability.
Tli. [I admit it ; but often the idea you have of the object
of which you speak, is still more general than that of this
child, and I doubt not that a blind person can speak pertinently
of colors and make a speech in praise of the light which he
does not know, because he has learned its effects and circum
stances.]
§ 4. Ph. Your remark is quite true. Men often apply their
thoughts more to words than to things, and because they have
learned most of these words before becoming acquainted with
the ideas which they signify, not only children, but also grown
up men often speak like parrots. § 5. But men ordinarily mean
to indicate their own thoughts, and further they attribute to
words a secret relation to the ideas of another and to things
themselves. For if the sounds were attached to another idea
by the one with whom we are conversing, it would be necessary
x
306 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
to speak two languages. It is true that one does not stop too
much to examine what the ideas of others are, and our idea is
supposed to be that which the common people and the scholars
of the country attach to the same word. § 6. This is particu
larly the case as regards simple ideas and modes ; but as
regards substances the belief* is more particularly that the
words signify also the reality of things.
T/L [Substances and modes are equally represented by
ideas; and things, as well as ideas, in both cases are indi
cated by words ; thus I see but little difference, save that
ideas of substances and of sensible qualities are more fixed.
For the rest, it sometimes happens that our idaas and thoughts
are the matter of our discourse and constitute the thing itself
which we desire to signify, and that reflective notions enter
more than we think into those of things. We speak, indeed,
sometimes of words in a material way, without in this case
being able to substitute with precision in the place of the
word its signification or its relation to the ideas or things.1
1 Leibnitz here points out a source of manifold, far-reaching and influential
errors, especially fatal in philosophy, viz. the hypostasizing of concepts, i.e.
regarding and using universal thought-symbols as substances, a consequence
of the excessive use of abstract terms. To these errors thus arising from the
imperfection and abuse of words and their influence on the mind, Francis
Bacon, 1561-162(>, in his Nor. Ory. Bk. I., Aphor. 43, 59, 60, gives the name
of idolufori, idols of the market-place, and says they are "omnium molestis-
sima " — " the most troublesome of all." These words are either names merely
of non-existent things or of things supposed to exist because of these names,
or are names obtained by " vicious and unskilful abstraction" -"mala et
imperita abstractione " — from a few objects and indiscriminately applied to
all other things having the faintest analogy thereto. The best ed. of Bacon's
Workx is that of Ellis, Spedding, and Heath, 2d ed., 7 vols., London: Long
mans, 1870-72. The Nov. Ory., in Latin, is in Vol. 1, the Eng. trans, in Vol. 4
of this ed. Editions of the Nov. Ory. (Latin) have been published with Eng.
notes, and an Eng. trans, in a separate vol., by G. W. Kitchin, Oxford: Clar
endon Press, 1855; and with Introd., Notes, etc., by Thos. Fowler, Oxford:
Clarendon Press, 1878.
For Leibnitz's estimate of Bacon, whose DC -Any- Scient. he mentions
among the writings which happily chanced to come into his hands when a
youth, and with otbers helped to direct his studies in the right path, whom he
enumerates among " the founders of modern philosophy," and whose method
he applied in his reform of the science of language, '.•/. Gerhardt, Die philos.
Schrift. »\ G. W. Leibniz, Vols. 1 : 196; 3 : 7, 1(5; 4 : 143, Erdmann, Leibnit.
opera philos., p. 61, b; G. 4 : 64, E. 23, a; G. 4 : 105, E. 45, a, also G. 7 : 325,
E. 110, b; G. 4 : 337, 343; 7 : 52, 53, E. 91, b, 92; G. 7 : 07; 7 : 495, Dutens.
Lfibnit. opera omnia, 5: 368; 6 : 303: G. 7 : 518, E. 421, a. Cf. also John
Mchol, Bacon, Vol. 2, pp. 238-239 (Philos. Classics), Edinburgh: Wm. Black-
CII. ni] ON HUMAN UNDERSTANDING 307
This occurs not only in speaking as a grammarian, but also in
speaking as a lexicographer, in giving the explication of the
term.]
CHAPTER III
OF GENERAL TERMS
§ 1. Ph. Although particular things alone exist, the larg
est number of words are general terms, because it is impossible,
§ 2, for each particular thing to have a particular and distinct
name; besides the fact that in such case a prodigious memory
would be necessary, in comparison with which that of certain
generals who could call by name all their soldiers would be
nothing. The matter indeed becomes infinite, if every animal,
every plant, and even every leaf of a plant, every grain, in
short every grain of sand, which might need a name must
have its name. [And how name the parts of things sensibly
uniform, as water, fire ?] § 3. Besides, these particular names
would be useless, the principal end . of language being to
excite in the mind of him who listens to me an idea similar to
mine. [Thus the similitude suffices, which is indicated by
general terms.] § 4. And particular words alone would not
serve to extend our knowledge, [nor to make us judge of
the future by the past, or of one individual by another.]
§ 5. But as it is often necessary to mention certain individuals,
particularly of our species, use is made of proper names; which
are given also to countries, towns, mountains and other dis
tinctions of place. And horse-jockeys give proper names
even to their horses, as well as Alexander to his Bucephalus,
in order to be able to distinguish this or that particular horse
when he is out of their sight.
Th. [These remarks are good, and some of them agree
with those I was about to make. But I would add, in accord
ance with the observation I have already made, that proper
n((/nes have been ordinarily appellatives, that is to say, general
wood & Sons, 1889. For a brief comparison of Leibnitz and Bacon and of
their philosophies, rf. J. T. Merz, Leibniz, pp. 21, 71 (Blackwood's Philos.
Classics) , Edinburgh : 1884. — TR.
308 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
in their origin, as Brutus, Caesar, Augustus, Capito, Lentulus,
Piso, Cicero, Elbe, Rhine, Ruhr, Leine, Ocker, Bucephalus,
Alps, Brenner or Pyrenees ; for you know that the first
Brutus had this name from his apparent stupidity, that
Caesar was the name of a child drawn by incision from the
womb of his mother, that Augustus was a name of veneration,
that Capito is a large head as also Bucephalus, that Lentulus,
Piso, and Cicero were names given in the beginning to those
who cultivated in particular certain kinds of vegetables. I
have already said what the names of these rivers signify,
Rhine, Ruhr, Leine, Ocker. And you know that all rivers are
still called Elbe in Scandinavia. Finally Alps are mountains,
covered with snow (with which agrees album, white) and
Brenner or Pyrenees signifies a lofty pride, for bren was high
or chief (as Brennus) in Keltic, as also brinck with Low-
Saxons is pride, and there is a Brenner between Germany and
Italy as the Pyrenees are between Gaul and Spain. Thus I
would venture to say that nearly all words are originally gen
eral terms, because it will only rarely happen that an express
name will be invented without reason to indicate one such
individual. We can say then that the names of individuals
were names of a species which was given par exceUen<;e or
otherwise to some individual, as the name large head to that
one of the whole city who had the largest or who was the
most important of the large heads which were known. Thus
it is indeed that we give names of genera to the species, i.e.
that we shall content ourselves with a term more general or
more vague to designate more particular species, when we
have no concern for their differences. For example, we are
contented with the general name, wormwood, although there
are so many species of it that one of the Bauhins1 has filled a
book expressly with them.]
1 Jean Bauhin, 1541-1613, a Swiss physician and naturalist, who devoted
himself chiefly to hotany, and with his brother Gaspard, 15<iO-l(>24, also a
physician and botanist, was born at Basel, whither his father, an eminent
French physician, had fled in exile because of his conversion to Protestant
ism. He studied with the celebrated botanist Fuchs at Tubingen, and after
travelling and collecting plants in the Alps, in France, and in Italy, became,
in 1570, physician to Duke Ulrich of Wurtemberg at Montbeliard, where he
remained till his death. The work of his to which Leibnitz here alludes is
entitled De plantis absinthii nomen habentibus. It appeared at Montbeliard
CH. in] ON HUMAN UNDERSTANDING
§ 6. Ph. Your reflections upon the origin of proper names
are very just; but to come to that of appellative names or
general terms, you will doubtless agree, sir, that words
become general when they are signs of general ideas, and
ideas become general when separated by abstraction from
time, place, or such other circumstances as may determine them
to this or that particular existence.
Th. [I do not deny this use of abstraction, but it is rather
in ascending from species to genera than from individuals
to species. For (paradoxical as it may appear) it is impos
sible for us to have the knowledge of individuals, and to
obtain the means of determining exactly the individuality of
anything, at least of keeping it by itself ; for all the circum
stances may reappear ; the smallest differences are to us insen
sible ; place or time, far from determining themselves, need
themselves to be determined by the things they contain. The
most important factor in the problem is the fact that individu
ality includes infinity, and only he who is capable of com
prehending it can have the knowledge of the principle of
individuation of this or that thing. This arises from the
influence (understanding it healthfully) of all things in the
universe upon each other. It is true that this would be
the case, if the atoms of Democritus existed, but in that case
also there would be no difference between two different individ
uals of the same form and size.]
§ 1. Ph. It is, however, wholly evident that the ideas which
children frame of persons with whom they converse (to con
fine ourselves to this example) are similar to the persons
themselves, and particular only. The ideas they have of
their nurse and their mother are very well traced in their
minds, and the names nurse and mamma, which children use,
relate only to these persons. Afterwards when time has
shown them that there are many other beings resembling
in 1593. His most important work, composed with the assistance of his fellow-
countryman and son-in-law Cherler, and containing descriptions of about 5000
plants with 3577 figures, is the Historia ttnirersalis plantarum nova et absolu-
tissima, Yverdun, 1050-1(551, 3 vols., fol. An abridgment of this great work
was published by Chabree, of Geneva, with the title Sriayraphin, 106(5, con
taining in one volume all the figures, together with all of importance on the
nomenclature and number of species in the great work. He was one of the
founders of modern botany. — TK.
310 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
their father or mother, they form an idea in which they find
that all these particular beings equally share, and they, as
others, give it the name of man. § 8. They acquire in the
same way names and notions more general ; for example, the
new idea of animal is not produced by any addition, but only
by removing the figure or the particular properties of man,
and retaining a body accompanied by life, feeling, and spon
taneous movement.
Th. [Very well; but that shows only what I just said; for
as the child advances by abstraction from the observation of
the idea of man to that of the idea of animal, he has come
from the more specific idea observed in his mother or father
and in other persons to that of human nature. For in order
to discern that he had not the precise idea of the individual,
it is sufficient to consider that an ordinary resemblance would
deceive him easily and make him take as his mother another
woman. You know the story of the false Martin Guerre,1 who
deceived even the wife of the true, and the near relatives, by
resemblance united with skill, and embarrassed for a long
time the judges, even when the true Martin had arrived.]
§ 9. Ph. Thus this whole mystery of genus and species,
which makes so much noise in the schools, but which outside
of them is with reason so little regarded, this whole mystery,
I say, reduces itself solely to the formation of abstract ideas
more or less extended, to which certain names are given.2
1 Cf. Essais de Theodicee, Discours preliminaire, § 42, Gerhardt, 6, 74,
Erdmann, 491, b, Jacques, 2, 48. In the sixteenth century, Martin Guerre, a
gentleman of Gascony, disappeared from home. After a long absence, a man
by the name of Arnaud du Thil suddenly appeared, claiming to be Martin
Guerre, and was acknowledged by the wife of Guerre as her husband. She
had by him two children. Learning, afterwards, that her true husband was
in Flanders, she angrily delivered the impostor into the hands of justice. The
long trial, one of the most celebrated cases of the century, was brought to an
end by the sudden and unexpected arrival of the true Martin Guerre, and
Du Thil was sentenced to death. For further details, and the sentence in full,
cf. P. Larousse, Grand Diet. Universel de XIXs Siecle, Vol. 8, p. 1603, b, c.
A parallel case in recent times was the Tichborne trial in England. — TR.
2 The philosophies of Locke and Leibnitz present a sharp contrast on the
question of genera and species, and the real existence of the universal. Accord
ing to Locke, the question is a wholly empty one, an inheritance from the
unprofitable discussions of scholasticism. The general term, the universal, is
a purely subjective product of the more or less arbitrary activity of man in
abstraction, and has nothing whatever to do with reality. Leibnitz maintains
that the universal is the inner essence of things, and that the formation of
CH. in] ON HUMAN UNDERSTANDING 311
Th. [The art of classifying things into genera and species
is of no little importance and of much use both to the judg
ment and the memory. You know how important this is in
botany, not to speak of animals and other substances, and
without mentioning also beings moral and notional,1 as some
call them. Order largely depends upon it, and many good
authors so write that their entire discourse can be reduced to
divisions and subdivisions, according to a method which has
some relation to genera and species, and is of use not only in
retaining things, but also in finding them.2 And they who
have arranged all sorts of notions under certain titles or pre
dicaments subdivided have done a very useful thing.]
§ 10. Ph. In defining words, we avail ourselves of the germs
general terms is not a mere thought-expedient, but a legitimate and proper
apprehension of the true and the real. Cf. G. Harteustein, Locke's Lehre v. d.
mentichl. Erkenntniss in Veryleichuny m. Leibniz's Kritik derselbe'n, V.,
pp. 52 sq., also in his Histor. Philos. Abhandl., Leipzig, 1870, pp. 162 sq. — TR.
1 Notional or conceptional beings, begriffliche Wesen, entia rationis, are
those which, as Schaarschmidt says, ''serve to indicate that which without
being in the ordinary sense of the word substantial (first substance in the
language of Aristotle," <\f. Cntcyor. 5, 2a, 11; Wallace, Outlines of the Philos.
of Aristotle, §10, p.25; Zeller, Philos. d. Griech., II., 2 [Vol. 4], p. 304 *g., 3d eel.,
1879", but cf. also, Metaphys. VII., 7, 10:32i>, 2; Wallace, op. cit. § 34, p. (57,
Zeller, op. cit. II. 2 [Vol. 4], p. 344 sq.) " can still lay claim to an ideal reality."
For further discussion of the subjects of this and the note next preceding,
cf. Neiv Kxxai/s, Bk. III., chaps. 5, 0, Bk. IV., chaps. 4, 6. — TR.
2 Cf. Gerhardt, Leibniz, philos. Schrift. 7, 07: " Fuere tamen autores non
contemneudi, qui method um rebus junxere lit Theodorus Zwingerus, Job.
Thomas Freigius, Barthol. Kechermannus, et diligentissimus Job. Henr.
Alstedius, cujus Encyclopaedia mihi pro captu illorum temporum laudanda
videtur." Alsted, 1588-1(138, was Professor of Philosophy and Theology at
Herborn in Nassau, but applied himself chiefly to systemizing the several
branches of art and science. His Enci/dopfedia, Herbornire, 1(530, 7 vols., fol.,
reprinted Lugduni, 1049, 4 vols., fol. Leibnitz often mentions it (cf. G. 4, (i2,
74, E. 22, a, 28, b; Dutens, Leibnit. opera omnia, 5, 405, 507), and wrote down
some thoughts — cof/itata qiifcdam — for its enlargement and improvement;
cf. Dutens, 5, 183-185. The classified contents of the work are given in ihe
article "Encyclopaedia," in the Encydop. Brit. 9th ed., Vol. 8, p. 17(5. b
(American Reprint). Schaarschmidt states that the different works of R.
Goclen, as well as those of Alsted, are of the kind alluded to in the text.
Goclcn, 1547-1020, was Professor of Philosophy at Marburg, and published a
Lexicon philosophicurn , Marburg, 1(513, 1 vol., 4to, which, though of little
value, enjoyed from its novelty considerable celebrity at the time of its appear
ance. Leibnitz refers to this work in his third letter to Clarke: cf. G. 7, 305,
E. 752, b, J. 2, 420, I). 2, 122. Goclen was the 'discoverer and signalizer ' of
the Inverse, Regressive, or Goclenian Sorites, in comprehension ; cf. Hamilton,
Lects. on Lot/ic, XIX., p. 273, Amer. ed., and Goclenii Isayoye in Oryanum
Aristotelis, p. 255, Francof. 1598. — TR.
312 LEIBNITZ'S CRITIQUE OF LOCKE [UK. in
or the next general term ; and this is for the purpose of spar
ing ourselves the trouble of counting the different simple ideas
which this genus signifies, or sometimes perhaps for the pur
pose of sparing ourselves the disgrace of being unable to make
this enumeration. But although the shortest way of defining
is by means of genus and difference, as the logicians say, it may
be doubted, in my opinion, whether it is the best ; at least it
is not the only way. In the definition which states that man
is a rational animal (a definition which is perhaps not the
most exact, but which serves well enough the present pur
pose), instead of the word animal you might put its definition.
And this shows the little necessity of the rule which requires
that a definition must be composed of genus and difference,1 and
the little advantage there is in its strict observance. Thus
languages are not always made according to the rules of logic,
so that the meaning of each term may be exactly and clearly
expressed by two others. And those who made this rule have
done ill in giving us so few definitions conformable to it.
Tli. [I agree with your remarks ; it would be advantageous,
however, for many reasons, if definitions might consist of two
terms : it would without doubt greatly shorten them, and all
divisions could be reduced to dichotomies which are the best
species of divisions, and are particularly useful for invention,
judgment, and memory. I do not, however, think logicians
always demand that the genus or the difference be expressed
in a single word ; for example, the term regular polygon may
pass as the genus of the square, and in the figure of the circle
the genus might be a plane curvilinear figure, and the dif
ference might consist in the fact that all points of the circum
ference are equally distant from a certain point as centre.2
1 Cf. Aristotle, Topica, VI., 4, 141&, 26: 5ei Mei' Siarov -yeVov? *ai. TCOI/ 6ia(/>opd>v
6pi£ecrdai TOV xaAio? bpi^o/j-fvov f also I., 8, lOo*3, 15 : eTreifirj 6 optcr/ubs e/c •yeVovs (cat Sta^opajv
eo-TeV, and Wallace, Outlines, §§ 14, 15, 25; Zeller, Philos. d. Griech., I.L, ^
[Vol.4], p. 2r>5.— TR.
2 Leibnitz rightly takes exception to Locke's censure of Aristotle's rule
regarding definition, given in the preceding note, viz. : that it must consist of
the genus and the species-forming difference, remarking that genus and dif
ference may very often be interchanged, the possibility of this interchange
depending upon the principle on which, or the point of view from which, the
classification is made, or upon the closeness with which the genus and the
species-forming difference approach each other, it being essential to valid
interchange that they be actually alike, or so nearly so that the difference is
cii. in] ON HUMAN UNDERSTANDING 313
For the rest, it is also well to remark that very often the genus
may be changed into a difference and the difference into a
genus. For example, the square is a regular quadrilateral, or
rather a four-sided figure that is regular, so that the genus
or the difference seems to differ only as the substantive and
adjective ; as if, instead of saying that man is a rational living
being (animal raisonnable) , language allowed the statement
that man is a living rational being (rational animable), i.e.
a rational substance endowed with an animal nature ; while
genii l are rational substances whose nature is not animal or
common with the animals. And this interchange of genera
and differentia 'depends upon the variation of the order of the
sub-divisions.]
§ 11. Ph. It follows from what I have just said, that what
is called general and universal belongs not to the being (exist
ence)2 of things, but that it is a work of the understanding,
§ 12, and the essences of each species are only abstract ideas.
Th. [I do not quite see this consequence. For generality
consists in the resemblance of separate things among them
selves, and this resemblance is a reality.]
§ 13, Ph. I was going myself to say to you that these species
are founded upon resemblances.
Th. [Why, then, not seek therein also the essence of genera
and species ?]
§ 14. Ph. You wrill be less surprised to hear me say that
these essences are the work of the understanding, if you con
sider that there are at least complex ideas which in the minds
of different persons are often different collections of simple
ideas, and thus what is avarice in the mind of one man is not
so in the mind of another.
practically of no account. Cf. New Essays, Bk. III., chap. 3, ante, p. 308.
Such definitions, while not strictly logical or scientific in the full sense of these
terms, but tentative rather, and, as it were, popular, are nevertheless useful,
and indeed necessary, in ordinary life and in science, where we must classify
to a certain extent for the sake of relative clearness, but where strict logical
definition is not essential, or is impossible because of the insufficiency of our
knowledge. Logically exhaustive definition, save in the realm of pure thought
and in such sciences as the pure mathematics, is possible only to an infinite
mind who possesses exhaustive knowledge of all principles and facts involved.
Exhaustive knowledge of an individual demands an exhaustive knowledge of
all other individuals. Cf. N. E., Bk. III., chap. 3, § 6, Th., ante, p. 309.— TR.
1 I.e. angels and archangels. — TR.
2 Locke has : " real existence," Philos. Wks., Vol. 2, p. 14 (Bonn's Ed.).— TR.
314 LEIBNITZ'S CRITIQUE OF LOCKE [BK. m
Th. [I admit, sir, that there are few cases in which I have
less understood the force of your inferences than here, and
this troubles me. If men differ in the name; does it change
the things or their resemblances ? If one applies the name
avarice to one resemblance, and another to another, there will
be two different species designated by the same name.]
Ph. In that species of substance which is most familiar to
us and with which we are most intimately acquainted, it has
many times been doubted whether the offspring brought into
the world by a woman was a man,1 even to discussing whether
he should be fed and baptized. This could not be if the ab
stract idea or the essence, to which the name man belongs,
were the work of nature, and not a diverse, uncertain collection
of simple ideas which the understanding put together, and to
which it attached a name, after having made it general by
way of abstraction. So that at bottom each distinct idea,
formed by abstraction, is a distinct essence.
Th. [Pardon me for telling you, sir, that your language
perplexes me, for I do not see its connection. If we cannot
always discern by the outside the internal resemblances, are
there less of them in nature ? When we doubt whether a
monster is a man, we doubt whether it has reason. When we
know it has, the theologians will order it to be baptized, and
the jurisconsults, to be fed. It is true that we may dispute
about the lowest species logically considered, which vary by
accidents in one and the same physical species, or species by
direct descent (tribu de generation),2 but we do not need to
determine these ; we may, indeed, vary them infinitely, as is
seen in the great variety of oranges, lemons, and citrons, which
experts know howr to name and distinguish. The same thing
was seen in tulips and pinks when these flowers were in
fashion. For the rest, the fact that men unite these or those
ideas, or even that nature actually unites them or riot, makes
no difference as regards essences, genera, or species, since the
question only concerns possibilities, which are independent of
our thought.]
1 Cf. Locke, Philos. Works, Vol. 2, p. 17, and note (Bohn's Ed.). — TR.
2 Cf. Neiv Essays, Bk. III., chap. (>, § 14, Gerhardt, 5, 288, line 14; Erdmann,
31,3, a; Jacques, 1, 234. The term "species," in Leibnitz's day, denoted not
merely similarity of external form and characteristics, but more essentially
the genetic relationship of common descent. — TR.
CH. in] ON HUMAN UNDERSTANDING 315
§ 15. Ph. The species of each thing is ordinarily supposed
to have a real constitution, and 'it is beyond doubt that some
real constitution must exist upon which every collection of
simple ideas or qualities co-existing in this thing must depend.
But as it is evident that things are ranked in sorts or species
under certain names only as they agree with certain abstract
ideas to which we have attached these names, the essence of
each genus or species comes thus to be nothing else than the
abstract idea signified by the general or specific name, and we
shall find this to be the import of the word essence, according
to its most ordinary use. It would not be a bad thing, in my
opinion, to designate these two kinds of essences by two
different names, and to call the one real, and the other, nominal
essence.
Th. [It seems to me that our language makes extreme inno
vations in the method of expression. We have indeed spoken
hitherto of nominal and causal or real definitions, but not
within my knowledge of essences other than real, at least by
nominal essences have not been understood false and impos
sible essences, which appear to be essences, but are not; as,
for example, would be that of a regular decahedron, i.e. of a
regular body comprised within ten planes.1 Essence is at
bottom nothing less than the possibility of that which we
think. What we assume as possible is expressed by the defi
nition; but this definition is only nominal when it does not
express at the same time, possibility ; for then we may doubt
whether this definition expresses anything real, i.e. possible,
until experience comes to our aid to make us know this reality
a posteriori? when the thing is actually found in the world :
and this suffices for the defect of the reason, which made us
know the reality a priori 2 by exposing the cause or the possible
generation of the definite thing. It does not then depend on
us to unite ideas as seems good to us ; at least, this combination
is not justified either by reason which shows it as possible, or
by experience which shows it as actual, and consequently, also
possible. In order the better to distinguish, also, essence and
1 This figure is impossible, the only possible regular polyhedrons being
the tetrahedron, hexahedron, octohedron, dodecahedron, and icosahedron. —
TR.
2 Cf. ante, p. 227, note 2. — TR.
310 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
definition, you must consider that there is only one essence of
the thing, but that there are many definitions which express
one and the same essence, as the same structure or the same
city may be represented by different scenographies according
to the different sides from which it is regarded.]
§ 18. 1 Ph. You will, I think, agree with me that the real
and the nominal are always the same in simple ideas and in
the ideas of the modes ; but in the ideas of substances, they
are always entirely different. A figure which bounds a space
by three lines is the real as well as the nominal essence of
the triangle ; for it is not only the abstract idea to which the
general name is annexed, but the essence or proper being of
the thing, or the foundation whence proceed its properties,
and to which they are annexed. But it is wholly otherwise
as regards gold. The real constitution of its parts, upon which
its color, weight, fusibility, firmness, etc., depend, is unknown
to us ; and, having no idea of it, we have no name that is its
sign. Yet these are the qualities which cause the matter to
be called gold, and are its nominal essence, i.e. which give it a
right to the name.
Tli. [I should prefer to say, in accord with received usage,
that the essence of gold is that which constitutes it and whicli
gives it these sensible qualities, which make it known and
which make its nominal definition, while we should have the
real and causal definition if we could explain this contexture
or internal constitution. But the nominal definition is here
found real also, not by itself (for it does not make known
a priori the possibility or the genesis of bodies), but by experi
ence, because we have experience of a bod}^ in which these
qualities are found together : but without this we might doubt
whether so much weight would be compatible with so much
malleability, as it may be doubted, even at present, whether a
glass malleable by cold is possible in nature.2 I am not, for
the rest, of your opinion, sir, that there is here the difference
1 § 18, in Locke, Philos. Works, 2, p. 19 (Bohn's ed.) ; so Gerhardt : Erdmann,
Jacques, and Schaarschmidt in his German translation, have § 19. — TR.
2 Cf. Pliny the Elder, 23-79, Histor. Natur., Bk. 36, chap. 66 ; Eng. trans.
(Bohn's Class. Lib.), Vol. 6, p. 381, London, 1857. " In the reign of Tiberius,
it is said, a combination was devised which produced a flexible glass. . . . This
story, however, was, for a long time, more widely spread than well authenti
cated " — " fama crebrior quam certior." — TR.
en. in] OX 11U.MAN UNDERSTANDING 317
between the ideas of substances and the ideas of predicates, as
if the definitions of predicates (i.e. of the modes and the
objects of simple ideas) were always real and nominal at
the same time, and that those of substances were only nominal.
I quite agree that it is more difficult to have real definitions
of bodies, which are substantial existences because their con
texture is less sensible. But it is not the same with all sub
stances ; for we have a knowledge of true substances or unities
(as God and the soul) as intimate as we have of the most of
the modes. Besides, there are some predicates as little known
as the contexture of bodies ; yellow or bitter, for example,
are objects of simple ideas or notions (phantasies1), and yet we
have only a confused knowledge of them.2 The case is the
same in mathematics, where one and the same mode may have
a nominal as well as a real definition. Few people have
clearly explained in what consists the difference between these
two definitions which must distinguish, also, essence and prop
erty. In my opinion, this difference is that the real shows
the possibility of the thing defined, and the nominal does not.3
1 Schaarschinidt translates : " die Gegenstande einfacher Vorstellungen oder
Phantasiebilder." — TR.
2 'Cf. New Essays, Preface, ante, p. 48, ad Jin, and Bk. IV., chap. 6, § 7, Th.
(2) , infra, p. 458. According to Leibnitz, sense-knowledge is confused, and needs
to be developed into clearness and consistency by the discriminative analysis
and unifying power of thought. Phenomena such as colors, sounds, etc., the
subjective counterpart or resultant of specific sense-energies, resist all further
analysis, and while clear as wholes, are composite, insoluble, and so confused
as regards their single elements. Such wholes admit only descriptive, not,
strictly speaking, logical definition. Cf. Med. de Cor/., Ver., ct Id. ad init.,
Gerhardt, 4. 422, Erdmann, 78, a, trans. Duncan, Philos. Works of Leibnitz, 27.
-TR.
3 Cf. ante, pp. 17, 201, and Med. de Cor/., Ver., et Id., Gerhardt, 4, 424,
Erdmann, 80, b, trans. Duncan, Philos. Works of Leibnitz, 30; also G. 0,
405, E. (5:57, a, Dutens, Leibnit. opera omnia, I, 439; 6, 44; G. 7. 194 and note.
As the nominal definition explains a thing according to the name, \ve may have
nominal definitions of objectively non-existent or of impossible things, as
centaurs, griffins, or any of the creatures of the fancy or the imagination, or
the decahedron mentioned in § 15, Th., of this chapter, ante p. 315. The real
definition explains the thing to be defined by exhibiting its cause or generation,
its rise out of its conditions, i.e., its possibility; it is thus identical with the
genetic definition, and Leibnitz accordingly calls it the causal definition, ante
p. 31(>. Cf. also Dewey, Leibniz's New fissays, 210; Hamilton, Logic, 343;
Trendelenburg, Ueber d. Element d. Definition in Leibniz. Philosophie in
Histor. Beitr. z. Philos., Berlin, 1867, Vol. 3, pp. 48-62. Trendelenburg calls
special attention to the fact that Leibnitz, in definition, has in mind especially
the analytical element, explaining definition as an unfolding of the concept,
318 LEIBNITZ'S CRITIQUE OF LOCKE [UK. in
The definition of i\\To parallel straight lines, which states that
they are in one and the same plane and will not meet although
continued to infinity, is only nominal, for we could at once
doubt whether that is possible. But when we have under
stood that we can draw a straight line in a plane parallel to
a given straight line provided we take care that the point of
the style describing the parallel remains always equally distant
from the given line, we see at once that the thing is possible,
and why they have this property of never meeting, which con
stitutes their nominal definition, but which is the sign of the
parallelism only when the two lines are straight, while if one
at least were curved, they might be by nature unable ever to
meet, and yet not on that account be parallel.
§ 19. Ph. If essence was something else than the abstract
idea it would not be ingenerable 1 and incorruptible. A uni
corn, a mermaid, a perfect circle, perhaps do not exist in the
world.
Th. [I have already told you, sir, that essences are perpetual,
because here the question concerns only the possible.]
CHAPTER IV
OF THE NAMES OF SIMPLE IDEAS
§ 2. Ph. I confess I have always believed that the forma
tion of the modes was arbitrary : but as regards simple ideas
and those of substances, I have been persuaded that, besides
possibility, these ideas should signify a real existence.
Tli. [I see no necessity for it. God has ideas before creating
the objects of these ideas, and nothing prevents Him from
being able also to communicate such ideas to intelligent creat
ures : there is also no exact demonstration proving that the
objects of our senses and of the simple ideas which the senses
or its resolution into several concepts equivalent to the one concept — " definire
est explicare notionem, resolvere in plures notiones uni aequivalentes ; " <-;/'.
Dutens, op. cit.,±, (58 : " definitio nihil aliud, quam accurata nominis explicatio
est": G. 4, 140, P". (iO, b : "definitio enim nihil aliud est, quam significatio
verbis expressa, sive brevius, significatio signifieata." — TR.
1 Locke's word, Philos. Works, Vol. 2, p. 20 (Bonn's ed.). — TR.
OH. iv] ON HUMAN UNDERSTANDING 319
present to us are outside us.1 This fact has especial weight
in the case of those who believe with the Cartesians and with
our distinguished author, that our simple ideas of sensible
qualities have no resemblance to that which is outside us in
the objects ; there would then be nothing requiring these ideas
to be grounded in any real existence.2]
§§ 4, 5, 6, 7. Ph. You will grant me at least this other
difference between simple and complex ideas, that the names
of simple ideas cannot be denned, while those of complex ideas
can be. For definitions should contain more than one term,
each of which signifies one idea. Thus you see what can or
cannot be defined, and why definitions cannot go on to infinity ;
a remark which no one, so far as I know, has up to this time
made.
Th. [I have also made the statement in the brief Essay
upon Ideas? inserted in the " Actes de Leipzic" about twenty
years since, that simple terms cannot have nominal definitions ;
but I have there added at the same time the statement that
terms, when they are simple only as regards us (because we
have no means of analyzing them so as to reach the elementary
1 The demonstrability of the reality of that which lies at the basis of the
phenomena of the senses is one of the most difficult problems in the theory of
knowledge — Erkenntnisslehre. Leibnitz seems nowhere to have discussed the
question, at least in this form, nor to have asked himself how, agreeably to
his philosophical system, a knowledge of the reality of the external world
could be demonstrated or a belief therein justified. So far as his system sug
gests any answer consistent with itself, that answer is found in his doctrine of
pre-established harmony, in the consciousness of which we pass immediately
from our inner representative world of ideas to belief in the reality of the
external things thus ideally represented. This, however, like Descartes'
attempt to bridge the chasm from the subjective to the objective by his doctrine
of God's veracity, is mere assumption, not "exact demonstration." The
problem belongs to both psychology and metaphysics, and is satisfactorily
discussed and solved only when considered in these two aspects. Leibnitz was
an idealist in psychology, and a realist in metaphysics, and never really har
monized or united these two points of view. For him, therefore, there could
be ''no exact demonstration" of the external reality of "the objects of our
senses and of the simple ideas which the senses present to us." Cf. Discount
de Metaphj/sique, §§ 2<i so., Gerhardt, Leibniz, philos. tfc/iriff., 4. 451 sq., E.
Caird, The Crit. Philos. of Jmmanuel Kant, I, <%-i)5. New York, Macmillan
& Co., 1889. — TR.
2 Cf. New Essay*, Bk. II., chap. 8, §§ 21, 24, ante, pp. 1 83-135 ; also Bk. IV.,
chap. 11. The constancy of sense-phenomena is the constraining reason for
referring them to something real. Cf. Dewey, Leibniz's New Essays, 173 sq.;
Gerhardt, Leibniz, philos. Schrift. 7, .">19 sq. — TK.
3 Cf. ante, p. 14, note 2; p. 227, note 3. — TR.
320 LEIBNITZ'S CRITIQUE OF LOCKE [UK. in
perceptions of which they are composed), as heat, cold, yellow,
green, can receive a real definition which would explain their
cause. Thus, the real definition of green is that of an entity
composed of blue and yellow thoroughly mixed,1 although
green is no more susceptible of a nominal definition by which
we may recognize it than blue or yellow. Terms on the other
hand which are simple in themselves, i.e. whose conception is
clear and distinct, cannot receive any definition, whether
nominal or real. You will find in this little Essay, placed in
the " Actes de Leipzic," the foundations of a large part of
the doctrine concerning the understanding, briefly explained.]
§§ 7, 8. Ph. It were well to explain this point and to indi
cate what can be defined, what not. And I am tempted to
believe that often great disputes are raised and much nonsense
introduced into men's discourse from a failure to consider this
matter. These celebrated trifles about which so much stir is
made in the schools have arisen from the fact that no attention
has been paid to this difference which is found in ideas. The
greatest masters in the art have been constrained to leave
the majority of simple ideas without defining them, and when
they have undertaken to define them, they have not succeeded.
What more superfine nonsense, for example, could the mind of
man invent than that which is contained in this definition
of Aristotle : Motion is the realization of that which is 2^ossible
so far as it is possible ?2 § 9. And the moderns who define
motion as passage from one place into another, merely put one
synonymous word in the place of another.
Tli. [I have already remarked in one of our past conferences
that you consider many ideas as' simple which are not so.
Motion is of this number which I believe to be definable ; and
the definition which states that it is a change of place is not
to be despised. Aristotle's definition is not so absurd as you
1 This is true of pigments, but not of lights. Blue and yellow lights when
mixed produce white light. — TR.
2 Cf. New Essays, Bk. II., chap. 21, § 1, Th. ante, p. 174. For Aristotle's
definition, Cf. PhyS. AcrOUS., III., 1, 201&, 4: 1? roO dwarov, y Swarov, evTe\eXei.a
<f>avepbv ore Kivrjerts e<niv, 201a, 11 : *j Tc3 6vva/u.ei OVTOS evreAexeia, 77 TOIOVTOV, K^Tjert?
eo-Tiv, MetCtphyS. K, 9, 1065b, 16 : iV ™i) Swdpei. # TOIOVTOV eanv evepyiav Ae-ya>
Kivrjo'LV, 23 '. V S*? TOW Suva/uei OVTO?, orav evre\t\eia bv evepyrj rj avrb r) aAAo 17 KIVJ^TOV,
Kivwis eanv, also 33 ; Wallace, Outlines of the Philos. of Aristotle, § 42, p. 77 ;
Zeller, Philos. d. Griec., 3d ed., 1879, II., 2 [Vol. 4], p. 350 sq., with the notes.
— TR.
CH. iv] ON HUMAN UNDERSTANDING 321
think, this supposed absurdity arising from the failure to
understand that the Greek KU/^O-I? with him did not signify
wjiat we call motion, but what we would express by the word
change, whence it comes that he gives it a definition so abstract
and metaphysical, while what we call motion is called by him
<f>opd, latio, and is found among the species of change
§ 10. Ph. But you will not apologize, at least, for the same
author's definition of light as the action of the transparent.2
Th. [I find it, as you do, very useless ; 3 and he makes too
frequent use of his action, which does not tell us much.
Diaphanous is for him a medium across which we can see ;
and light is, according to him, that which consists in the
actual passage. Well and good.]
§ 11. Ph. We agree, then, that our simple ideas cannot
have nominal definitions, as we cannot know the taste of pine
apples by the accounts of travellers, unless able to taste things
by the ears, as Sancho Panza had the power to see Dulcinea by
hearsay,4 or as that blind man who, having been heard to speak
boldly of the brilliancy of scarlet, thought it must resemble
the sound of the trumpet.
Th. [You are right ; and all the travellers in the world
1 Cf. P/ll/S. Ad'OaS., VII. 2, 243a, (5 Sq. .' ^^ 5e rpeZ? eio-t Kifr/creis, rj re Kara -roirov
<f>opa, T; <5e Kara TO iroCov aAAoiWis, 17 Se Kara TO •novov avf rjeri? /cal <j>0i<rt.<;, Eill. NIC. X.,
3, 1174a, 30: ei ydp «<"-ii> »j «/>opA KiVijo-ts woOev nol (Alex. Grant, The Elki<:s of
Arintotle, Vol. 2, p. 324, line 17, 3d ed., London: Longmans, Green, & Co.,
1874); Wallace, Outline*, § 42; Zeller, P/tilos. d. Griec., 3d ed., 1879, II., 2
[Vol. 4], p. 389 57.— TR.
'•2 (Jf, Jjf, Anil)l<'l, II., 7, 418^, 9: <f><ii)S 6e kativ r\ TOUTOV ei'e'pyeta TOU fitaqbayoCs r\
Sia^avts, 419a, 11 : ') 5' evTcAe^eia TOV 8ia<l>avov<; </)d)? eart't'. E. Wallace, Aristotle's
Psychology in Greek in id Entjli^h w. Introd. and Notes. Cambridge: Univ.
Press, 1882, pp. 95, 97, translates the two passages: " Light then is the expres
sion of the pellucid (jua pellucid," "The full play of this pellucid constitutes
light," and, in his Introd., p. Ixxi., combines them thus : " Light therefore may
itself be defined as the actual expression or full play of the pellucid as pellucid."
Cf. also Zeller, Philos. d. Griec.. 3d ed., 1879, II., 2 [Vol. 4], p. 477, note 2.
3 Schaarschmidt calls attention to "a bad typographical error" in the text
of Raspe's edition of the Nouveaux Essais at this point. Raspe reads '; fort
utile," for which Schaarschmidt proposes "futile." Gerhardt, Erdmann, and
Jacques all read " fort inutile," which gives the requisite sense, and is accord
ingly followed in the translation. — TR.
4 Cf. Cervantes, 1547-1610, Don Quixote, Pt. 2, chap. 9, ad med. ; also, Pt. 1,
chap. 31. — TR.
Y
322 LEIBNITZ'S CRITIQUE OF LOCKE [UK. in
could not give by their words what we owe to a gentleman
of this country who cultivates successfully pine-apples three
leagues from Hannover, almost upon the bank of the Weser,
and who has found means of multiplying them to such an
extent that some day we can perhaps have them of our own
growing in as great abundance as the oranges of Portugal,
though there would apparently be some loss in the flavor.]
§§ 12, 13. Ph. It is wholly otherwise with complex ideas.
A blind man can understand what a statue is ; and a man who
had never seen the rainbow could understand what it is, pro
vided he had seen the colors which compose it. § 15. But
though simple ideas are inexplicable, they are the least doubt
ful. [For experience accomplishes more than definition.]
Tli. [There is, however, some difficulty as to the ideas which
are only simple as regards us. For example, it would be diffi
cult to indicate precisely the limits of blue and of green, and in
general to discriminate colors closely approaching one another,
while we can have precise notions of the terms used in arith
metic and geometry.]
§ 16. Pit. Simple ideas have further this peculiarity that
they have very little subordination in what the logicians call
the line of predication (ligne predicamentale) ,l from the lowest
1 Leibnitz here refers to the Tabula loyica, in which Porphyry, 233-304, and
after him the Scholastic logicians, such as Lambert of Auxerre, c. 1250, Petrns
Hispanus, c. 1226-1277, Raimund Lulli, 1234-1315, the Pseudo-Thomas, and
Johannes Majoris Scotus, 1478-1540, sought, in connection with the live pre-
dicables, to arrange in strict logical subordination by the process of dicho
tomic or bifurcate division, all genera and species from the highest genera to
the lowest species, between which is found the scale of subordinate notions
which are at the same time both genus and species. This Tabula logica was
called by the later commentators, who added the diagram illustrating it, not
found in Porphyry, the arbor Porphyriana or the arbor praedicamentalis, and
the line of subordination from the highest genus to the lowest species was called
the linea praedicamentalis or praedicabilis, or the or do praedicamentalis. Cf.
Porphyry, Eto-ayto-yT? chap. 2, 1 b. 40 sq. (in Aristotle, ed. Berl. Acad., Vol. 4,
p. 1) ; "'Efijyijo-is, f. 18 b., Paris, 1543, 4to ; Prantl, Gesch. d. Loaik im Abend-
lande, Leipzig, 1855-1870, Vol. 1, pp. 627-8, note 41, 633-4, note 07, Vol. 3, pp.
28, note 14: " Praedicamentum autem nihil aliud est, quam ordinatio prae-
dicabilium in linea praedicabile secundum sub et supra et a latere et in linea
recta, . . . unde ilia tota ordinatio, quae est inter genus generalissimum et
speciem specialissimam et genera subalterna et differential collaterals, voca-
tur unum praedicamentum, sicut patet in arbore Porphyrii in tractatu Prae-
dicabilium." (Lambert of Auxerre, Summa loyicae, Paris, MS., Cod. Sorbonn.
1797), 46, note 168, 151, note 42, 252, note 315, c/. n. 311, Vol. 4, p. 249, note
434; also, Jevons, Elementary Lessons in Logic, p. 103 sq. — TR.
CH. iv] ON HUMAN UNDERSTANDING 323
species to the highest genus. The reason is that the lowest
species being only a simple idea, nothing can be taken from
it; for example, nothing can be taken from the ideas of white
and red in order to retain the common appearance in which
they agree. For this reason, they are included with yellow
and others, under the genus or the name, color. And when
men wish to frame a still more general term, comprising, also,
sounds, tastes, and tangible qualities, they avail themselves of
the general term, quality, in the sense ordinarily given it to
distinguish these qualities of extension, number, motion, pleas
ure, and pain, which act upon the mind and introduce into it
their ideas by more than one sense.
TIi. [I have something more to say upon this remark. I
hope that here and elsewhere you will do me the justice, sir,
to believe that this is not from a spirit of contradiction,
and that the subject seems to demand it. It is not an advan
tage that the ideas of sensible qualities have so little subordina
tion and are capable of so few subdivisions ; for it arises only
from the fact that we know little of them. But the fact itself
that all colors have the common property of being seen by
the eyes, of all passing into bodies from which one or more
of them reappear, and of being reflected from the polished
surfaces of bodies which do not allow them to pass, shows us
that something can be taken from the ideas we have of them.
Colors may indeed be divided with good reason into extremes
(one of which is positive, viz. white ; and the other privative,
viz. black) ; and into means, which are called colors,1 however,
in a particular sense, and which spring from light by refrac
tion ; which furthermore may be subdivided into those of the
convex side, and those of the concave side of the broken ray.
And these divisions and subdivisions are of not a little conse
quence.]
Ph. But how can you find genera in simple ideas ?
Th. [As they are simple only in appearance, they are
accompanied by circumstances which are bound up with them,
1 Gerhardt reads: " et en moyens qu'on appelle encor couleurs dans un
sens particulier et qui naissent de la lumiere par la refraction ; qu'on pent
encor," etc. ; Erdmann and Jacques read: " et en moyens qu'on appelle encore
sous-diviser," etc. ; i.e. and into means which you are further called upon to
subdivide, etc. — TR.
324 LEIBNITZ'S CRITIQUE OF LOCKE [UK. in
although this bond is not understood by us, and these circum
stances furnish somewhat that is explicable and susceptible
of analysis, which gives also some hope that hereafter the
reasons of these phenomena may be discovered. Thus it
happens that there is a kind of pleonasm in our perceptions of
sensible qualities, as well as sensible masses ; and this pleonasm
is, that we have more than one notion of the same subject.
Gold may be denned nominally in several ways ; you may say
that it is the heaviest of our bodies, that it is the most malle
able, that it is a fusible body which resists the cupel and aqua
fortis, etc. Each of these marks is good and is sufficient for
the recognition of gold, at least provisionally and in the present
state of our bodies, until a heavier body is found, as some
chemists maintain is the case in their philosopher's stone, or
until that Luna Jixa 1 is shown, which is a metal said to have
the color of silver, and almost all the other qualities of gold,
and which Chevalier Boyle - seems to say he has produced.
Thus you may say that in matters which we know only
empirically, all our definitions are merely provisional, as I
believe I have already remarked above. It is then true that
we do not know demonstratively whether a color may not pos-
1 Of. Fratris Bosilii Valentini Benedict iner Ordens CJii/mische Schrift.,
Hamburg, 1700, Ft. I., p. 272: " AVenn das Gold seiner Aniwa auch verlustig
wird / giebt es ein weiss Corpus und einen fixen weissen Gold-Leib / der von
den suchenden Studenten / und von den Jiingern der Kunst eine Luna fix a
getaufft und genanntwird: " Ft. II., p. 381, Schluss-Reden Fr. Basilii Valentini,
Tract. 1, Sectio iii., De Magneta vulgi, § 3: "Mitdem Magnet und Antimonio
wird auch eine Lnnafixa gemacht / welche alsdann durch das Oleum Mart is
& Veneris f/radirt [sir], und zu Gold gemacht wird: Jedorh kan mans mi t
Antimonio und Eisen auch verrichten." Martin Ruland, Lexicon alchemize,
Francofurti, 1K12, p. 308: "Luna compacta est argentum fixum vel aurum
album : Silber fix oder weiss Gold." Robert Boyle, Works, ed. Birch, 5 vols.,
fol. : London, 1744, A7ol. 1, p. 215; 2d ed., 6 vols., 4to : London, 1772, Vol. 1, p.
335, Vol.3, p. 28. — TR.
2 Robert Boyle, l(>27-lf>91, a distinguished natural philosopher and chemist,
the discoverer of the law of the compressibility of gases, which, confirmed by
its independent discovery by Mariotte in 1(57(5, has since been known as
" Boyle and Mariotte's Law." He was one of the founders of the Royal Society
of London, and by his will established the "Boyle Lectures." Leibnitz often
refers to him, cf. New Essans, Preface, ante, p. 47. — The title of Boyle's work
there referred to is, Of Absolute Rest in Bodies, Works, ed., Birch, (> vols.,
4to, London, 1772, Vol. 1, pp. 443-457, in which he opposes the doctrine with
convincing reasons; — Bk. IA\, chap. 12, § 13, Th., infra, p. 526; Gerhardt,
Leibniz philos. Schrift., 7, 342 ; Dutens, Leibnit op. om., 5, 98: 6, 107; Leib
nitz's estimate of his experiments, 6, 318; Eulogy, 0, Ft. II., 217. — TR.
CH. v] ON HUMAN UNDERSTANDING 325
sibly be produced by reflection alone without refraction, and
whether the colors we have hitherto noticed in the concavity
of the angle of ordinary refraction are not found in the con
vexity of a kind of refraction hitherto unknown, and vice versa,
Thus the simple idea of blue would be stripped of the genus
which we have assigned it in our experiences. But it is well
to stop at the blue we have and at the circumstances attending
it. And it is something that they furnish us the means of
making genera and species.]
§ 17. Ph. But what say you of the remark that has been
made that simple ideas, since they are taken from the existence
of things, are nowise arbitrary, while those of the mixed modes
are wholly so, and those of substances to some extent ?
Tli. [I believe that the arbitrary quality is found only in
the words, and not at all in the ideas. For they express
only possibilities. Thus, if there had never been a parricide,
and if all the legislators had been as cautious as Solon in
speaking of it, parricide would be a possible crime, and its
idea would be real. For ideas are in God from all eternity ;
and indeed they are in us before we actually think of them,
as I have shown in our previous conversations.1 If any one
wishes to take them as the actual thoughts of men, it is per
mitted him to do so, but he will oppose himself without reason
to the accepted language.
CHAPTER V
OF THE NAMES OF MIXED MODES AND RELATIONS
§§ 2, 3, seq. Ph. But does not the mind form mixed ideas
by bringing together simple ideas as suits its purpose, without
the need of a real model ; while simple ideas arise for it
1 Cf. New Essai/s, Preface, ante, p. 42, sq., Bk. I., chap. 1, § 1, sq., ante,
p. 70, xtj., where Leibnitz develops more fully the thought repeated here.
Leibnitz assumes that ideas — the pure truths of reason— exist in man, and
come into consciousness by the self-development of the spirit. These ideas
contain in themselves the potential representation of all possible reality, the
realization of which is directly proportional to the measure of man's self-
development. In God this realization is complete, since in his thought all
real possibility is always actually represented. — TB.
326 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
without choice, through the real existence of things? Is not
the mixed idea often seen before the existing thing ?
Tli. If you take the ideas as actual thoughts, you are right.
But I do not see that it is necessary to apply your distinction
to that which concerns the form itself, or the possibility of
these thoughts, and yet this is the question in the ideal world
which is distinguished from the existing world. The real
existence of beings which are not at all necessary is a matter
of fact or of history ; but the knowledge of possibilities and
necessities (for necessary is that the opposite of which is not
at all possible) constitutes the demonstrative sciences.1]
Ph. But is there more connection between the ideas of
killing and of man than between the ideas of killing and of a
sheep? Is parricide composed of more connected notions than
infanticide ? And is it more natural that what the English
call stabbing, i.e., murder by a thrust, or by striking with the
point, which is a greater wrong with them than killing by
striking with the edge of the sword, should have deserved a
name and an idea which is not accorded, for example, to the
act of killing a sheep, or of killing a man by cutting ?
Th. [If the question concerns only possibilities, all these
ideas are equally natural. Those who have seen sheep killed
have had an idea of this act in thought, although they have
not deigned to give it their attention.2 Why, then, limit our
selves to names, when the question concerns ideas themselves,
and why occupy ourselves with the worth of the ideas of
the mixed modes, when the question concerns these ideas in
general ?]
§ 8. Ph. Men form arbitrarily different kinds of mixed
modes, so that words are found in one language for which
there are no corresponding words in another. There are no
words in other languages corresponding to the word Versura '3
1 Cf. New Essays, Preface, ante, p. 43. — TB.
2 Erdmann reads : " qnoiqu'ils ne lui aient point donne de nom et ne 1'aient
point daigne de leur attention; " Jacques reads, after "daigne," "honorer,"
otherwise like Erdmann. The rendering then is : although they have not
given it a name, nor have they vouchsafed (to honor — Jacques) it (with)
their attention. — TR.
3 "Versura," literally "a turning round," means, in classical usage, "the
borrowing of money to pay a debt," a process which resulted simply in
changing one's creditor, not in extinguishing the obligation. Cf. Cicero, Episl.
CH. v] ON HUMAN UNDERSTANDING 327
used among the Romans, nor to Corban,1 used by the Jews.
We boldly translate the Latin words hora. pes, and libra, by
hour, foot, and pound ; but the ideas of the Romans were very
different from ours.
Th. I see that many things which we discussed when the
question was that of ideas themselves and their kinds, come
back now, under cover of the names of these ideas. The
statement is true as regards the names and the customs of
men, but it changes nothing in the sciences and in the nature
of things. It is true that he who would write a universal
grammar would do well to pass from the essence of languages
to their existence, and compare the grammars of many lan
guages. In like manner, an author who should write a univer
sal jurisprudence drawn from reason, would do well to unite
with it the parallel laws and customs of peoples, which would
be of service not only in practical life, but also in his reflec
tions, and would give him occasion to consider many points
which would otherwise escape him. But in science itself,
apart from its history or existence, it is of no consequence
whether people are or are not conformed to the dictates of
reason.]
§ 9. Ph. The doubtful signification of the word species makes
the statement that the species of mixed modes are made by
the understanding offensive to some people. But I leave it to
others to consider who fixes the limits of each sort or species,
for these two words are for me wholly synonymous.
ad Atticum, 5, 15, 2; Tacitus, Ann., 6, 1G. As a proverb, the word means
"to get out of one difficulty by getting into another." Cf. Terence, Phormio,
5, 2, 15; Lactantius, 2, 8, 24. — TR.
1 "Corban," Hebrew JS"^, N.T. /cop^av, i.e. fiwpoi', originally an offering to
God of any kind, particularly in fulfilment of a vow. The original use was
in course of time altered by the traditionalists, and the offerer of the gift
interdicted from using it for himself, or giving it toothers. The " corban "
furnished a ready means to any one who wished to relieve himself from any
inconvenient obligation, as of assisting his parents in poverty or distress ; he
simply brought his gift to the temple and offered it to God, saying, "Let it
be corban," and departed free, as he said, from any further responsibility in
the matter. It was this utter perversion of the spirit of the law, with its
resultant positive wrong-doing, that Christ so severely rebuked. Cf. Mark
7: 11-1-3; Matt. 15:5, <>; and H. A. AV. Meyer, Krit. Excti. Kowmmtar if. d.
N.T., (>th ed., Gottingen, 187(5— I., 2 [Vol. 2], p. 104; I., 1 [Vol. 1], p. 333;
Smith's Diet, of the Bible, ed. Hackett and Abbot, New York, 1877, Vol. 1,
p. 491. — TR.
328 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
Tli. [The nature of things ordinarily fixes the limits of
species ; for example, of man and beast, of cut and thrust. I
admit, however, that there are some notions in which the limit
is truly arbitrary ; for example, the question of determining a
foot, for, the straight line being uniform and indefinite, nature
indicates therein no limits. There are also essences, vague
and imperfect, into which opinion enters ; as when you ask
how little hair must be allowed a man in order that he be not
bald. This was one of the sophisms of the ancients, when one
pressed upon his adversary:
Dum cadat elusus rations mentis acervi.1
But the true answer is that nature has not determined this
notion, and that the opinion has its share therein that there
are some persons regarding whom it may be questioned whether
they are bald or not, and that there are some doubtful persons
who will pass as bald with some and not with others, as you
remarked that a horse which will be considered small in
Holland, will pass as a large one in the country of the Gauls.
There is indeed something of this nature in simple ideas, for
I just observed that the final limits of colors are doubtful.
There are also essences truly half-nominal, in which the name
enters into the definition of the thing ; for example, the degree
or quality of doctor, chevalier, ambassador, king, is recognized
when a person has acquired the recognized right to avail him
self of this name. And a foreign minister, however complete
his power and however extended his train, will not pass as
an ambassador unless his letter of credence gives him the
name. But these essences and ideas are vague, doubtful, arbi
trary, nominal, in a sense a little different from those which
you have mentioned.]
§ 10. Ph. But it seems that the name often conserves the
essences of the mixed modes which you think are not arbitrary ;
for example, without the name triumph, we should have but
little idea of what took place among the Bomans upon that
occasion.
Tli. [I agree that the name serves to call attention to things
and to conserve the memory and the actual knowledge of them ;
i Horace, Epist. 2, 1, 47. — TR.
CH. v] ON HUMAN UNDERSTANDING 329
but that accomplishes nothing as regards the point in question,
nor does it render the essences nominal ; and I do not under
stand why you gentlemen absolutely require that the essences
themselves should depend upon the choice of names. It would
have been desirable that your distinguished author, instead of
insisting upon that, had preferred to enter into a much more
detailed account of ideas and of modes, and to have set them
in order and developed the varieties. 1 would have followed
him on this road with pleasure and with proht. For he would
doubtless have given us much light.]
§ 12. Ph. When we speak o£ a horse, or of iron, we regard
them as the things which furnish us the original patterns of
our ideas ; but when we speak of mixed modes or, at least,
of the most important of these modes, which are moral entities,
— for example, justice, gratitude, — we consider their original
modes as existing in the mind. Therefore we say the notion
of justice, of temperance ; but we do not say the notion of a
horse, of a stone.
Th. [The patterns of the ideas of the one are as real as
those of the ideas of the other. The qualities of the mind
are not less real than those of the body. It is true you do
not see justice as you see a horse, but you understand it no
less, or rather you understand it better ; it is no less in acts
than directness or obliqueness is in motions, whether you
consider it or not. And to show you that men are of my
opinion, and men, indeed, the most capable and most experi
enced in human affairs, I have only to avail myself of the
authority of the Roman jurisconsults, followed by all others,
who call these mixed modes or these moral entities, things,
and in particular, incorporeal things. For servitudes,1 for ex
ample (like that of the passage through the ground of one's
neighbor), are writh them res incorporates, in which there is a
property which may be acquired by long use, and may be
possessed and reclaimed. As for the word notion, many clever
people have considered it as large as that of idea ; Latin usage
1 Qf. Sandars, Institutes of Justinian, Lib. II., Tit. III., p. 118, 8th ed.,
London: Longmans, Green, & Co., 1888; Poste, Gains, Elements of Roman
Law, Bk. II., 29, 31, pp. 165-6, .'id ed., Oxford, 1890; Mommsen, Digest, Lib.
VIII., 1, Vol. 1, p. 250, Berlin: Weidmann, 1870; Hadley, Introd. to Roman
Law, pp. 158-161, 180-196, New York, D. Appleton & Co., 1881. — TR.
330 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
is not opposed thereto, nor do 1 know whether that of the
English or the French is contrary to it.1]
§ 15. Ph. It is further to be remarked that men learn the
names before the ideas of the mixed modes : the name showing
^
them that this idea deserves to be observed.
Th. [This remark is a good one, although it is true that
now-a-days children, with the aid of nomenclators, ordinarily
learn the names not only of the modes, but also of substances,
before the things, and indeed rather the names of substances
than of the modes; for it is a defect in these same nomen-
clators that they employ nouns^ only, and not verbs ; not con
sidering that verbs, although signifying the modes, are more
essential in conversation than the majority of nouns, which
indicate particular substances.2]
CHAPTER VI
OF THE NAMES OF SUBSTANCES
§ 1. Ph. The genera and species of substances, as of other
beings, are only sorts. For example, suns are a sort of stars,
i.e. they are fixed stars, for it is not without reason that we
think each fixed star would make itself known as a sun to
a person placed at a proper distance. § 2. Xow that which
limits each sort is its essence. It is known either by its
interior structure, or by external indications which make us
recognize it and call it by a certain name : and thus it is that
we may recognize the clock of Strasburg either as the clock-
maker who made it, or as a spectator who sees its effects.
Th. [If this is your statement, I have nothing to oppose
to it.]
1 Cf. New Esscn/s, Bk. II., chap. 22, § 2, Th. ante, p. 222; Discours de Metn-
phi/siqiie, l(58fi, § 29, Gerhardt, 4, 452. For the meaning and use of these terms :
in Latin, iile.a, notin, concepts* or conreptio ; in French, idee., notion, concep
tion ; in German, Idee., VorsteUtnif/, Ber/riff; in English, idea, notion, con-
c.option or concept, which varies according to the period in the history of
thought in which they are employed, and according to the theory of knowledge
implicitly or consciously held by the author using them, cf. Krauth-Flemming,
Vocnb. of the Philos. Sciences, ed. of 1S77, sub roc. — Tit.
"For," as Schaarschmidt says, " the activity is first perceived, and hy its
means the substance recognized and formulated." — TR.
CH. vi] ON HUMAN UNDERSTANDING 331
Ph. I express myself in a way suited not at all to renew
our discussions. But I add that the essence is related only
to sortSj and that nothing is essential to individuals. An
accident or a disease may change my color or shape ; a fever
or a fall may take away my reason or memory ; apoplexy
may leave me neither feeling, understanding, nor life. If
you ask me if it is essential to me to have reason, I reply :
no.
Tk. [I think that there is something essential to individuals
and more than you suppose. It is essential to substances to
act, to created substances to suffer, to minds to think, to bodies
to have extension and motion. That is, there are some sorts
or species to which an individual cannot (naturally at least)
cease to belong, when it has once been of their number, what
ever revolutions may happen in nature. But there are some
sorts or species, which are accidental (I admit) to the indi
viduals, which may cease to belong to them. Thus you
may cease to be healthy, beautiful, wise, and indeed to be
visible and palpable, but you cannot cease to have life and
organs and perception. I have stated sufficiently, above, why
it appears to men that life and thought sometimes cease,
although they cease not to endure and to have their effects.]
§ 8. Ph. Many individuals ranked under a common name,
considered as belonging to one species only, have nevertheless
very different qualities depending upon their real (particular)
constitutions. This is easily observed by all those who ex
amine natural bodies; and chemists often are convinced of it
by sad experience, when they vainly seek in one portion of
antimony, sulphur, and vitriol for the qualities which they
have found in other portions of these minerals.
Th. [Xo statement has more truth, and I could myself even
furnish intelligence concerning it. Books have also been written
expressly de infido experimentorum chymicorum muressu. But
the error consists in taking these bodies as similar or uniform,
while they are more mixed than we suppose; for in di.^hnilar
bodies we are not surprised to remark differences between
individuals, and physicians do not know how much the tem
peraments and natural dispositions of human bodies differ.
In a word, we shall never find the final logical species, as I
have already remarked above, and two real or complete indi-
LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
viduals of one and the same species are never perfectly
alike.1]
Ph. We do not notice all these differences, because we do
not know the little parts, nor consequently the interior struct
ure of things. Thus we do not avail ourselves of them in
order to determine the sorts or species of things, and if we
wished to do so by means of these essences, or by what the
schools call substantial forms, we should be like a blind man
who desired to arrange bodies according to colors. § 11. We
do not indeed know the essences of spirits, we know not how
to form distinct specific ideas of angels, although we well
know that there must be many kinds, of spirits. Thus it
seems that in our ideas we put no difference between God and
the spirits by any number of simple ideas, save that we attribute
infinity to God.
Th. [There is, however, another difference in my system
between God and created spirits, viz. that in my view all
created spirits must have bodies, just as our soul has one.2]
§ 12. Ph. I think at least that there is this analogy between
bodies and spirits, that as there is no gap in the varieties of
the corporeal world, so there will be no less variety in intelli
gent creatures. Commencing from ourselves and proceeding
even to the lowest things, a descent is made by very small
1 Cf. New EKSOI/S, Preface, ante, p. 51, Bk. II., chap. 27, ante, p. 238 sq. ;
De ipsa natura, § 13, Gerhardt, 4, 512, Erdmann, 158, b, Jacques, 1, 464 (in
French), trans. Duncan, Philos. Works of Leibnitz, 122,123; Monadolof/ie, § 9,
G. (5, 608, E. 705, J. 2, 392, trans. D. 219, 'F. H. Hedge, "Jour. Spec. Philos.,"
1, 129; 4th letter to Clarke, §§ 4 *</., G. 7, 372, E. 755, h, J. 2, 432, trans. D.247,
5th letter to Clarke, § 21, G. 7, 393, E. 765, J. 2, 449, trans. D. 258. This is the
principle of the identity of indiscernibles, principuim identitatis indiscerni-
bilium — i.e. that " things qualitatively undistinguishable are absolutely identi
cal." According to Leibnitz, there are' no such things, there being in the
universe no two objects perfectly alike ; though abstractly possible, they are
inconsistent with the order of things, and with the divine wisdom, which
admits nothing therein without reason. Cf. also Kant's development and
criticism of Leibnitz's principles in his Dilucidatio nova, 1755. Werke, ed.
Rosenkranz & Schubert, Leipzig, 1838-42, Vol. 1, p. 1; ed. Hartenstein, Leipzig,
1867-1)8, Vol. 1, p. 365, Krit. d. r. Vermmft, V. d. Amphibolie d. Reflexions-
bef/Htfe, ed. R. & S. 2, 214, ed. H. 3, 225, 4th ed., J. H. v. Kirchmann, 'Leipzig,
1877, p. 268 SQ., E. Caird, The Crit. Philos. of Immanuel Kant, 1, 106 sq., 445
sq., 500 sq., New York, Macmillan & Co., 1889; Ueberweg, Hist, of Philos.,
2, 144, 173, Ueberweg-Heinze, Gesch. d. Philos., 7th ed., 3, 215, 259. — TR.
2 Cf. Neic Essaj/s, Preface, ante, p. 52, Bk. II., chap, 1, § 12, Th. ante, p. 113,
chap. 15, § 4, Th. ante, p. 159, and note. — TR.
CH. vi] ON HUMAN UNDERSTANDING 333
degrees, and by a continued series of things, which in each
remove differ very little one from the other. There are fishes
that have wings, and to whom the air is not strange, and there
are birds inhabiting the water whose blood is cold like that of
the fishes, and whose flesh so strongly resembles theirs in
taste that the scrupulous are allowed to eat them on fish-
days. There are animals so closely approaching the species
of birds and of beasts that they hold the middle ground between
them. The amphibia contain both terrestrial and aquatic ani
mals. Seals live upon the land and in the sea; and porpoises
(whose name signifies sea-hog) have the warm blood and the
entrails of a hog. Not to speak of that which is reported of
sea-men,1 there are some animals who seem to have as much
knowledge and reason as some that are called men ; and there
is so close a relation between animals and vegetables, that
if you take the most imperfect of the one and the most perfect
of the other, you will scarcely perceive any considerable dif
ference between them. Thus, until we reach the lowest and
least organized parts of matter, we shall find everywhere species
bound together, and differing only by degrees almost impercept
ible. And when we consider the wisdom and infinite power of
the Author of all things, we have reason to think that it is con
formed to the magnificent harmony of the universe and to the
great design as well as to the infinite goodness of this sovereign
architect, that the different species of creatures ascend, also,
little by little from us towards his infinite perfection. Thus
we have reason to be persuaded that there are many more
species of creatures above us than below us, because we are
much more distant in degrees of perfection from the infinite
being of God than from that which approaches nearest to
nothing. Yet we have no clear and distinct idea of all these
different species.
Th. [I had intended in another place to say something not
unlike what you, sir, have just set forth ; but I am glad to
have been anticipated when I see that you state things better
than I could hope to have done. Clever philosophers 2 have
1 I.e. mermaids; so Locke, "mermaids or sea-men," Philos. Works, Vol. 2,
p.. 49 (Bohn'sed.). — TR.
2 Cf. Thdodicee, Pt. I., § 14, Gerhardt, 0, 110, Erdmann, 507, b, Jacques,
2, 80, Dutens, 1, 131 (in Latin) ; Reply to Bayle, ad fin., G. 4, 570, E. 1<H), b,
334 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
discussed this question: utrum detur vacuum formarum, i.e.
whether there are possible species, which, however, do not
exist, and which nature may seem to have forgotten. I have
reason to believe that all possible species are not compossible
in the universe, great as it is, and that, too, not only in rela
tion to things which exist contemporaneously, but also in
relation to the whole series of things. That is to say, I believe
that there are of necessity species which have never existed
and never will exist, not being compatible with this series of
creatures- which God has chosen. But I believe that all things,
which the perfect harmony of the universe can receive, exist
therein. That there may be intermediate creatures between
those which are far apart is in conformity with this same
harmony, although this is not always in one and the same
globe or system, and that which is between two species is
sometimes so in relation to certain circumstances and not in
relation to others. Birds, so different from man in other
things, approach him in speech ; but if monkeys could speak
like parrots, they would go farther. The law of continuity l
declares that nature leaves no gap in the order she follows ;
but every form or species is not the whole order. As for
spirits or genii, as I hold that all created intelligences have
organized bodies, whose perfection corresponds to that of the
intelligence, or the mind, which is in this body in virtue of
the pre-established harmony, I hold that in order to gain any
conception of the perfections of spirits above us, it will be of
great service to imagine these perfections also in bodily organs
which surpass our own. It is a case in which the liveliest
D. 2, 93: " II se peut cependant, que ce Chevalier ait encor eu quelque bon en-
thousiasme, qui 1'ait transports dans ce nwnde invisible, et dans cette etendue
infinie, dont il parle, et que je crois estrecelle des idees ou des formes, dont out
parle encor quelques Scholastiques en mettant en question, utruni detur
vacuum formarum." — TR.
1 Cf. New Essays, Preface, ante, p. 50, Bk. IV., chap. 16, § 12, Th., infra,
p. 552; Theodicee, III., § 348, Gerhardt, 6, 321, Erdmann, 605, b, Jacques, 2,
270; Letter to Bayle, in the " Nouvelles de la Republique des Lettres," July,
1687, G. 3, 52, E. 104, trans. Duncan, Philos. Works cf Leibnitz, 33; Letter to
Arnauld, 16'JO, G. 2, 136, E. 107, b, J. 1, 444, trans. D. 38. Animadversiones in
parteut generalem Princlpiorum Cartesianorum, Ft. II., ad Art. 45, G. 4, 375,
Duncan, 61 ; Guhrauer, G. W. Freiherr v. Leibniz, eine -Biographic, 1, 264,
and notes, pp. 31-33, a letter to an unknown person, Oct. 16, 1707, containing
a very clear statement of the principle or law of continuity; translation,
Appendix, pp. 712-714. — TR.
CH. vi] ON HUMAN UNDERSTANDING 335
and richest imagination, and, to avail myself of an Italian
term which. I cannot well express otherwise, the invenzione la
piu vaga, will be most timely in raising us above ourselves.
And what I have said in justification of my system of harmony,
which exalts the divine perfections beyond what we had dared
to think, will assist us also in having ideas of creatures in
comparably grander than we have had hitherto.
§ 14.1 Ph. To return for a little to the reality of species
even in substances, I ask you if water and ice are different
species ?
Th. [I, in my turn, ask you if gold melted in the crucible
and gold cooled in bullion are of one and the same species ?]
Ph. He does not reply to the question, who proposes an
other,
Qui litem lite resolvit.'2
But you thereby admit that the reduction of things to species
relates solely to the ideas we have of them, which suffice to
distinguish them by names ; but if we suppose that this dis
tinction is founded upon their real and internal constitution,
and that nature distinguishes existing things into so many
species by their real essences, in the same manner as we
ourselves distinguish them into species by these or those
names, we shall be liable to great mistakes.
Th. There is some ambiguity in the term species, or a being
of a different species, which causes all this confusion ; and
when we have removed it, there will no longer be discussion
save perhaps as regards the name. We may take species
mathematically and physically. In mathematical strictness
the least difference making two things in any respect dissimilar,
makes them different in species. Thus, in geometry, all circles
are of one and the same species, for they are all perfectly alike,
and for the same reason all parabolas are also of the same
species ; but it is not the same with ellipses and hyperbolas, for
of these there is an infinite number of sorts or species, as
well as an infinite number of each species. All the numberless
1 Locke has § 13, Philos. Work*, Vol. 2, p. 50. The numbering § 14 in the
French text of all the editions is an error, as will he seen upon comparing
the numbering of the next §, also 14, with Locke's text. Here also the texts
coincide with Locke's. — TR.
2 Cf. Horace, Satires, 2, 3, 103. — TR.
336 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
ellipses, in which the distance of the foci has the same ratio to
the distance of the apices, are of one and the same species ; but
as the ratios of these distances vary only in size, it follows that
all these infinite species of ellipses make only one genus, and that
there are no subdivisions. On the other hand, an oval of three
foci would have indeed an infinite number of such genera, and
would have an infinitely infinite number of species, each genus
having a number of them simply infinite. In this sense two
physical individuals will never be perfectly similar, and what is
more, the same individual will pass from species to species, for it
is never wholly similar to itself even for more than a moment.
But the men who establish physical species do not adhere to
this strictness, and it depends upon them to say that a mass
which they can make return to themselves under its first form
continues to be one and the same species in their view. Thus
we say that water, gold, quicksilver, common salt, continue
the same, and are only disguised in ordinary changes ; but
in organized bodies, or in species of plants and of animals, we
define species by generation, so that this similarity, which
comes or may have come from one and the same origin or
seed, would be of one and the same species.1 In man, besides
human generation, we fasten upon the attribute rational animal ;
and, although there are men who live like beasts all their
lives, we presume that it is not for want of faculty or principle,
but that it is through impediments which stand in the way
of this faculty. But it is not yet determined as regards all
the external conditions which we wish to regard as sufficient
to give this presumption. But whatever regulations men
make for their denominations and for the rights attached to
names, provided that their regulation is followed or made fast
and intelligible, it will be founded in reality, and they will
not be able to imagine species which nature, which includes
even possibilities, has not produced or distinguished before
them. As for the interior, although there is no external ap
pearance which is not based upon the internal constitution, it
is nevertheless true that one and the same appearance may
sometimes result from two different constitutions. But in
i Cf. New Essays, Bk. III., chap. 3, § 14, Th. (2), ante, p. 314; Dewey, Leib
niz's New Essays, p. 215 sq. — TR.
CH. vi] ON HUMAN UNDERSTANDING 337
that case there will be something in common, and this is what
we philosophers call the proximate formal cause. But although
this should not be, as if according to Mariotte l the blue of
the rainbow had an entirely different origin from the blue
of the turquoise, unless there were a common formal cause (in
which opinion I do not at all agree with him), and although
we should agree that certain apparent natures which make us
give names have nothing internal in common, our definitions
would not cease to be grounded in real species ; for the
phenomena themselves are realities. We can say, then, that
all which we truthfully distinguish or compare, nature dis
tinguishes or makes agree also, although she has distinctions
and comparisons which we do not know and which may per
haps be better than ours. Thus much care and experience is
yet necessary in order to assign genera and species in a manner
sufficiently like nature. Modern botanists think that the dis
tinctions taken from the forms of flowers most resemble the
natural order.2 But they find therein, however, still much
difficulty, and it would be advantageous to make comparisons
and arrangements not only upon a single character, like that
of which I have just spoken, which is taken from flowers,
and is perhaps the most suitable up to this time for a possible
system and convenient for learners, but also upon characters
taken from other parts and relationships of plants : each
basis of comparison deserving tables of its own ; 3 without
which we shall allow many subaltern genera, .and many com
parisons, distinctions, and useful observations to escape. But
the more thoroughly we examine the generation of species,
and the more we follow in the classifications the conditions
which are there requisite, the closer we shall approach the
natural order. Therefore, if the conjecture of some intelligent
persons were found true, that there is in the plant besides the
1 Cf. ante, p. 121, note 4. — TR.
2 Cf. Dutens, Leibnit. opera omnia, Vol. 2, Pt. II., p. 169 sq., Epistola G. G.
Leihnitii ad A. C. Gackenholtzium, M. D. De Methodo Botanica, April 23,
1701. -TR.
3 Cf. Mor. Wilh. Drobisch, Nene Darstg. d. Lor/ik, 3d ed., Leipzig, 1863,
p. 141 sq., where the so-called Collateral Distributions or Co-divisions, which
Leibnitz here calls to mind, and " which are of especial importance in Statis
tics," are discussed. Drobisch's work is considered " one of the most perfect
presentations of the subject-matter from the point of view of formal logic."
— TR.
LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
seed (la graine) or the recognized seed (la semence) correspond
ing to the egg of the animal, another seed which would deserve
the name masculine, i.e. a powder (pollen, visible very often,
though sometimes, perhaps, invisible, as the seed (la graine)
itself is in certain plants) which the wind or. other ordinary
accidents scatter in order to unite it with the seed which comes
sometimes from one and the same plant, and sometimes, also
(as in the hemp), from another neighboring plant of the same
species, which plant consequently will be analogous to the
male, though perhaps the female is never wholly destitute of
this same pollen; if this conjecture, I say, were found true,
and if the mode of generation of plants became better known,
I do not doubt that the varieties which would be noticed would
furnish a basis for very natural divisions. And if we had the
penetration of some superior geniuses and knew enough about
things, perhaps we should find therein fixed attributes for
each species, common to all the individuals and always sub
sisting in the same living organism, whatever alterations or
transformations may happen to it, as in the best known of the
physical species, the human, reason is such a fixed attribute,
granted to each individual, and never to be lost, although
it cannot always be perceived. But in default of this knowl
edge we avail ourselves of the attributes which appear to us
most convenient for distinguishing and comparing tilings, and
in a word, for recognizing in them species or sorts ; and these
attributes have .always their real grounds.]
§ 14. Ph. In order to distinguish substantial beings accord
ing to the usual supposition, that there are certain essences or
precise forms of things, whereby all existing individuals are
naturally distinguished into species, it would be necessary to
be assured, § l.">. first, that nature always proposes, in the
production of things, to make them participate in certain
regular and established essences, as models; and, § 16. sec
ondly, that nature always attains this end. But monsters
give us reason to doubt both. § 17. It would be necessary
to determine, in the third place, whether these monsters are
really a distinct and new species, for we find that some of
these monsters have few or none of those qualities which are
supposed to result from the essence of that species whence
they derive their origin, and to which they seem to belong in
virtue of their birth.
CH. vi] ON HUMAN UNDERSTANDING 339
Th. When it is a question of determining whether monsters
belong to a certain species, we are often reduced to conjecture.
This shows us that we are not, then, limited to external con
siderations, since we should divine whether the internal nature
(as, for example, reason in man) common to the individuals of
such a species, still suits (as birth makes us conjecture) these
individuals, in whom a portion of the external characteristics,
ordinarily found in this species, is lacking. But our incerti
tude nowise affects the nature of things, and if there is such
a common internal nature, it will or will not be found in
the monster, whether we know it or not. And if the internal
nature of any species is not found therein, the monster will be
of its own species. But if there were no such internal nature
in the species under discussion, and if the question was not
decided by birth either, then the external marks alone would
determine the species, and monsters would not belong to that
species from which they deviate, unless taken in a manner a
little va.gue and with some latitude ; and in this case, also,
our trouble in desiring to divine the species would be in vain.
This is perhaps what you mean by all the objections you make
to species taken as real internal essences. You ought then to
prove, sir, that no common internal specific mark exists, since
the external is wholly missing. But the contrary is found in
the human species in which sometimes children who have
some monstrosity reach an age in which they exhibit reason.
Why, then, could there not be something similar in other
species ? It is true that for want of knowledge of them we
cannot avail ourselves of it to define them, but the exterior
takes its place, although we recognize the fact that it is insuffi
cient for an exact definition, and that the nominal definitions
themselves in these instances are only conjectural ; and I
have already stated above how sometimes they are only pro
visional. For example, we might find a way to counterfeit
gold so that it might satisfy all the tests which we have up to
the present time ; but we might also then discover a new method
of testing which would give the means of distinguishing natural
gold from this ichich is artiJiciaUy made. The old journals at
tribute both (discoveries) to Augustus, Elector of Saxony;1
1 Augustus I., the brother of Maurice, was Elector 1553-158G, and, according to
Schaarschmidt, " shared with his wife, Anna of Denmark, the love for alchemy."
— Tit.
340 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
but I am not the man to guarantee this fact. But if it
were true, we could have a more perfect definition of gold
than we have at present, and if artificial gold could be made
in quantity and cheap, as the alchemists claim, this new proof
would be important ; for by its means we could preserve for
the human race the advantage which natural gold gives us in
commerce by its rarity, while furnishing ourselves with a
substance which is durable, uniform, easy to divide and to
recognize, arid precious in small volume. I wish to avail
myself of this occasion to remove a difficulty (see § 50 of the
chapter, u On the Names of Substances," in the author of
the Essay on Understanding}. The objection is made that in
saying : All gold is fixed, if we understand by the idea of gold
the mass of certain qualities in which fixedness is comprised,
we make only an identical and useless proposition, as if we
said : Fixedness is fixedness ; but if we understand thereby a
substance given a certain internal essence, of which fixedness
is a result, we shall not speak intelligibly, for this real essence
is wholly unknown. I reply that the body given this internal
constitution is designated by other external marks in which
fixedness is not comprised, as if any one said : the heaviest
of all bodies is also one of the most fixed. But all that is
only provisional, for we might some day find a volatile body,
as a new mercury, which would be heavier than gold, and upon
which gold would float, as lead floats upon our mercury.
§ 19. Ph. It is true that in this way we can never know
precisely the number of properties depending on the real
essence of gold unless we know the essence of gold itself.
§ 21. [But if we limit ourselves precisely to certain properties,
that will be sufficient to enable us to have exact nominal
definitions which will serve us for the present, reserving to
ourselves the privilege of changing the signification of names,,
if any new useful distinction is discovered.] But it is neces
sary at least that this definition correspond to the use of the
name, and be capable of being put in its place. This serves
to refute those who maintain that extension constitutes the
essence of body, for when it is said that one body gives an
impulse to another, the absurdity would be manifest, if substi
tuting extension (for body) we should say that one extension
puts in motion another extension by means of an impulse, for
CH. vi] ON HUMAN UNDERSTANDING 341
in addition solidity is necessary. In like manner no one will
say that reason, or that which makes man rational, makes
conversation ; for reason does not constitute the entire essence
of man ; there are rational animals who converse with each
other.
Th. I think you are right : for the objects of abstract and
incomplete ideas are not sufficient to give the subjects of all
the actions of things. But I think that conversation agrees
with all minds who can interchange their thoughts. The
scholastics are greatly troubled regarding the angelic method
of communication ; but if they would accord the angels subtile
bodies, as I do, following the ancients, they would experience
no further difficulty in that regard.1
§ 22. Ph. There are some creatures in the world which
have forms similar to ours, but are hairy and use neither
language nor reason. There are imbeciles 2 among us who
have exactly the same form as ourselves, but who are destitute
of reason, and some of them make no use of language. There
are some creatures, as it is said, which, with the use of lan
guage and of reason and a form similar in every other respect
to ours, have hairy tails ; at least, it is not impossible that
there are such creatures.3 There are others, where the males
have no beard, and others, where the females have. If you
ask whether all these creatures are men or not, whether they
1 Cf. New Essay x, Preface, ante, p. 52, Bk. III., chap. 6, ante, p. 332, note
2 ; also letters to Des Bosses, Sept. 20, Oct. 4, 1706, Gerhardt, 2, 316, 319,
Erdniann, 43!), 440. — TR.
'2 Locke has: "naturals," Phflos. Works, Vol. 2, p. 53 (Bohn's ed.). — TR.
3 The myth of men with tails, here mentioned and accepted as credible by
Locke, arose either from the superficial observation of African travellers, or
from their uncritical acceptance and rehearsal of the stories of such Negroes
as claimed to have seen such beings, assumed by them to be endowed with
reason, although covered with hair and furnished with tails — stories which
seem to rest upon a confusion of men with man-like apes, a confusion the
more naturally suggested as many tribes of negroes regard the apes as rational
but uncivili/ed human beings. The myth has been exploded in our day by the
knowledge furnished by scientific explorers into the interior of Africa (the
assumed abode of these beings), such as Dr. Georg August Schweinfurth, who
states that among the tribes of Central Africa the Dyoor, the Niam-niam, and
the Bongo, fasten upon themselves behind, as a part of their dress, the tails
of animals, as, for example, that of "the quereza monkey (Colobns)," or tails
"composed of the bast of the Sanseviera." Cf. his Im Herzen von Afrika,
English trans, by Ellen E. Frewer, 2 vols., New York: Harper & Bros.', 1874,
Vol. 1, pp. 201, 21)4-6, Vol. 2, pp. 2, 6, 11, 137. —TR.
342 LEIBNITZ'S CRITIQUE OF LOCKE [BK. m
belong to the human species, it is plain that the question
refers only to the nominal definition, or to the complex idea
we have made for ourselves in order to indicate it by this
name ; for the internal essence is absolutely unknown to us,
although we have reason to think that where the faculties, or
rather the external figure, are so different, the internal consti
tution is not the same.
Tit. I think we have in the case of man a definition at once
real and 'nominal. For nothing can be more internal to man
than reason, and ordinarily it makes itself well known. There
fore the beard and the tail will not be considered in comparison
with it. A man of the forest, though hairy, will make himself
recognized : and it is not the hair of a niagot l which excludes
him. Imbeciles lack the use of reason; but as we know by
experience that reason is often bound and cannot appear, and
as this happens in the case of men who have exhibited and
will exhibit reason, we make, probably, the same judgment
regarding these imbeciles upon other indications, i.e. upon
their bodily figure. It is only by these signs, united with
their birth, that we presume that infants are men, and will
manifest reason; and we are seldom deceived. But if there
were rational animals with an external form a little different
from ours, we should be embarrassed. This shows that our
definitions, when dependent upon the exterior of bodies, are
imperfect and provisional. If any one called himself an
angel, and knew, or knew how to do. things much above us, he
might be believed. If some one else, like Gonzales.2 came
from the moon by means of some extraordinary machine, and
told us credible things about his native country, he would pass
1 The Barbary ape. — TR.
2 Cf. T/Homme dans la Ivne, ou le voyaae clr'nneriqne fait cm inondc de la
lime, nouvellement de con vert par Dominique, Goinalcs, avanturier Expar/nol,
oiitremcnt dit le, Courier volant, mis, en. nostre lanr/iie pur J. B. I). (Jean Bau-
doin), Paris, U548, 8vo, pp. 17(5; reprinted Paris, 1000, with illustrations, and
also Paris. 1731, 1'Jnio. Brunet states that this is the French translation of
Franc. Godwin, Tito Man in the Moon, or a ilixmnrw of a. ro//ar/e tltiilier bi/
Dorninr/o Gonsales, London, 1038, also 1057, etc., 12nio; that it had some suc
cess, and that it is supposed that Swift hoi-rowed some passages from it for his
Gnllirer'K Travels. Cf. E. A. Poe, Works. New York, 1867, Vol. 1, p. 49, who
gives, in a note at the end of the story of " The unparalleled adventure of one
Hans Pfaall," the full title of the French hook, together with some account of
its contents, including the machine of Gouzales. — TR.
CH. vi] ON HUMAN UNDERSTANDING 343
as a lunar being, and yet we might accord him indigineity and
the rights of citizenship, with the title of man, entire stranger as
he would be to our globe ; but if he asked for baptism and
wished to be received as a proselyte of our law, I think that
we should see great discussions arise among the theologians.
And if communication were opened with these planetary men,
sufficiently approaching ourselves according to Huygens,1 the
question would require a universal council in order to know
whether we ought to extend the care of the propagation of the
faith even beyond our globe. Many would doubtless maintain
that the rational animals of these countries,, not being of the
race of Adam, have no part in the redemption of Jesus Christ ;
but others would perhaps say that we have not sufficient
knowledge either of the place where Adam has always been,
or of what has been done with all his posterity, since there
have been theologians, indeed, who believed that the moon
was the place of paradise ; and perhaps that with the plurality
we should conclude for the surest thing, viz., to baptize these
men upon condition that they be susceptible of baptism; but
I doubt whether we should ever wish to make them priests
in the Roman Church, because their consecration would always
be doubtful, and we should expose the people to the danger
of a material idolatry, according to the hypothesis of this
church. Happily the nature of things exempts us from all
these embarrassments ; but these bizarre fictions are useful in
speculation, in order rightly to know the nature of our ideas.
§ 2.3. Ph. Xot only in theological questions, but also on
other occasions some would perhaps wish to regulate them
selves by the race, and to say that in animals propagation by
the copulation of the male and the female, and in plants by
means of the seeds, keeps the supposed real species distinct and
entire. But this would serve only to fix the species of animals
and vegetables. What must be done about the rest ? And
even as regards these it is not sufficient, for if history is to be
believed, women have been gotten with children by magots.
And here is a new question : Of what species must such a
production be ? You often see mules and jumarts (see Diotion-
1 Cf. cnitc, p. l.r>0, note 3. Leibnizens u. Htn/f/hen's Briefwechseln, v. E.
Gcrlftnd, Berlin, 1HS1. — Tu
344 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
naire Etymologique de M. Menage 1), the first begotten bjr an
ass and a mare, the last by a bull and a mare. I have seen an
animal begotten of a cat and a rat, which had visible marks of
these two animals.2 Whoever will add thereto the monstrous
productions, will find that it is very hard to determine species
by generation ; and if it can only be done by that means, must
I go to the Indies to see the father and mother of a tiger, and
the seed of the tea-plant, and could I not otherwise decide
whether the individuals which come to us are of these species ?
Tli. Generation or race gives at least a strong presumption
(i. e. a provisional proof) and I have already said that very
often our signs are only conjectural. The race has sometimes
been contradicted by the figure, as when the child is unlike
the father and mother, and the mixture of figures is not
always the sign of the mixture of races ; for it may happen
that a female gives birth to an animal which seems to belong
to another species and that the mother's imagination alone
has caused this irregularity : to say nothing of what is called
mola* But as meanwhile we judge provisionally the species
by the race, we also judge the race by the species. For when
a forest child,4 taken from among the bears, who had many of
their ways, but who made himself known at last as a rational
animal, was presented to John Casimir,5 king of Poland, he
did not scruple to believe him of the race of Adam, and to
baptize him under the name of Joseph, although perhaps upon
the condition, si baptizatus non es, according to the usage of
the Roman church, because he might have been carried off by
a bear after baptism. We have not as^et sufficient knowledge
1 Cf. Dutens, Leibnit. op. om., 5, 350, 543; 6, Pt. II., 21, Gerhardt, 2, 530,
539. Grilles Menage, 1(513-1092. The first ed. was entitled Orif/ines dc la lanc/ue
fran<;oise, Paris, 1050, 4to. A new ed. appeared at Paris, 1094, fol., under the
name, Dictionnaire Etymologique de In lanc/ue fran^oise, etc.: and this was
afterwards enlarged and edited by A. F. Jault, Paris, 1750, 2 vo.ls., fol.— TR.
2 An instance of superficial observation and hasty inference, like that of
the men with tails above mentioned, ante, p. 341, note 3. — TR.
3 An amorphous fleshy mass in the uterus. — TR.
4 Sehaarschmidt states that J. H. F. Ulrich, in his German trans., with ad
ditions and notes, Halle, 1778-SO, of Raspe's CEuvres philosoph. latin.es etfran-
(;aises de feu Mr. Leibniz, "gives in a note, p. 139-140, information concerning
the child of the bears found in the forest, without, however, quoting the source
of his communications." — TR.
s John II., Casimir V., 1(509-1072. He was elected king of Poland in 1014,
and abdicated in 1(588. — TR.
CH> vi] ON HUMAN UNDERSTANDING 345
of the effects of the intermixture of animals : and often mon
sters are destroyed, instead of being brought up, whilst they
are seldom long lived. The belief is that mixed animals do
not multiply ; but Strabo l attributes propagation to the mules
of Cappadocia, and letters from China tell me that in neigh
boring Tartary there are race-mules. We see also that the
mixtures of plants are capable of preserving their new spe
cies.2 We do not always indeed know in the case of animals
whether it is the male or the female, or both, or neither,
which determines the species. The doctrine concerning the
eggs of females which the late Mr. Kerkring3 made famous,
seemed to reduce the males to the condition of moist air as
related to plants, which furnishes seeds with the means of
pushing and raising themselves from the earth ; following the
verses of Vergil which the Priscillianists 4 were wont to repeat :
1 Of. Geographica, p. 212, ed. Casaubon, 1620; Bk. V., chap. 1, § 4, ed. by
Gustav Kramer, Berlin, 1844-52, 3 vols., 8vo; English trans. Vol. 1, p. 316
(Bonn's Class. Lib.), London, 1887. — TR.
2 Of. C. Darwin, 1809-1882, Origin of Species, and the new inquiries and
investigations consequent upon it. — TR.
3 Theodore Kerkkrinck, 1640-1693, a Dutch physician, born at Amsterdam,
died at Hamburg, a fellow-pupil with Spinoza, 1632-1677, of a physician,
Francis Van der Ende, and author of works on medicine, anatomy, and chem
istry, among which was the one here referred to by Leibnitz: Anthropogenic
ichnographia sive conformatio foetus ab ovo usque ad ossificationis principia,
in siipplementum osteogenise fietuum, 4to, Amstelodami, 1671. His Opera
omnia anatomica, 2d ed., 4to, Lugd. Bat., 1717. Cf. Dutens, Leibnit. op. om.,
5, 173. 199; F. Pollock, Spinoza: His Life and Philosophy, p. 13. — TR.
4 The Priscillianists were an heretical sect which appeared in Spain toward
the close of the fourth century, and continued till about the middle of the
sixth. Their speculative doctrines are a combination of Christianity with
Gnosticism and Manichreism. Their moral system was rigidly ascetic, and
celibacy was required. The charges of immorality and licentiousness so fre
quently brought against them by their adversaries, "are, to say the least, not
sufficiently well authenticated." The information that they made use of these
verses of Vergil, to which they attached a religious dogma, as a foundation
for their heresy and alleged sexual license comes from a letter of Jerome,
c. 346-420, to Ctesiphon, Epist. 133 ad Ctesiphontem, Opera, ed. Vallarsi,
Verome, 1734-42, Vol. 1, p. 1029, a; 2d ed., Venetiis, 1766-72; J. P. Migne,
Patrol, s. Lat., Vol. 22, p. 1150-51, Paris, 1845, latest ed., Paris, 1864-6(5. Cf.
also Sulpicius Severus, 363-40(5, or 410, Histor. Sacra, or Chronica, Bk. II.,
chaps. 46-51, and Dialog., III., 11-13, ed. C. Halm, Vienna, 1866 (Vol. 1 of the
Corpus Script. Eccles. Latinorum), and J. Bernays, Die Chronik des Sulp.
Severus, Berlin, 1861: A. Neander, Hist, of the Christ. Relig. and Church, 2,
771-779, Boston, Hough ton, Mifflin & Co.; Gibbon, Decline and Fall, Milman's
ed., chap. 27 ; Smith and Wace, Diet, of Christ. Biog., 4, 470-478, London, John
Murray, 1887.— TR.
346 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
Cum pater onmipotens fcecundis imbribus sether
Conjugis in Isetse gremium descendit et omnes
Magnus alit magno commistus corpore foetus.1
In a word according to this hypothesis the male would no
longer be more than the rain. But Leeuwenhoek2 has reha
bilitated the masculine genus, and the other sex is in its turn
degraded, as if it performed only the earth's function as
regards seeds, by furnishing them place and nourishment ; a
view which might obtain even if we still maintained the
theory of the eggs. But this does not prevent the imagination
of the female from having a great influence upon the form
of the foetus, even if we supposed that the animal has already
come from the male. For this is a condition destined ordi
narily to a great change, and much more susceptible also to
extraordinary changes. It is asserted that the imagination of
a woman in this condition, who was shocked by the sight of a
cripple, caused the separation of the hand of the foetus very
near its term, and that this hand was subsequently found in
the after-birth ; a statement, however, which requires confir-
1 Georg., 2, 325-327. — TR.
2 Antoon van Leeuwenhoek, 1632-1723, a distinguished Dutch naturalist,
"the father of scientific microscopy," who shares with Malpighi, 1628-1694,
the discovery of the capillary circulation of the blood, thus completing the
doctrine of Harvey, 1598-1G57, and with his own pupil, Ludwig Hamrn, the
discovery of the active moving constituents of the seminal fluid, which he called
" animalcula spermatica," or ''spermatozoa." Leeuwenhoek communicated
his discovery, 1677, of the spermatozoa in a letter to Sir Christopher AVren,
1631-1723, President of the Royal Society, 1681, " De ovario, et imaginovis ejus
ovis; homo ex animalcule oritur." The letter is found in Leeuwenhoek's
Arcana naturse detecta sive epistolse ad societatem Reyiam Anyliam scriptse,
Delft, 1695, 4to, p. 28 sq. Leeuwenhoek strenuously opposed the doctrine of
"spontaneous generation," and did more than any other naturalist to over
throw it. Cf. Dutens, Leibnit. op. om., 5, 173, 174, 319, 337; 6, Pt. I., 211, 213,
218, Gerhardt, Leibniz, philos. Schrift., 3, 562, 565, 571, 579, 580, Dutens, 2,
Pt. I., 329, 330; Pt. II., 214, Protoyssa, § 17; Si/stem e nouveau, § 6, Ger
hardt, 4, 480, Erdmann, 125, b, Jacques, 1, 471, trans. Duncan, Philon. Wks. of
Leibnitz, 73; Principes de la Nature et de la Grace, § 6, G., 6, 601, E., 715, b,
trans. D., 212 ; G., 7, 568. He published the greater part of his discussions and
investigations in 112 papers in the Philos. Transactions of the Royal Society,
and in 2(5 papers in the Memoirs of the Paris Academy of Sciences, of both
of which bodies he was a member. The most complete collection of his works
is the Opera omnia sen arcansd naturse ope microscopiorum detecta, Leyden,
1719-22, 4 vols., 4to; from this, Select Works, trans, by Samuel Hoole, London,
1800-1807, 2 vols, 4to, does not contain the letter to Wren. There is a Life in
Dutch by Haaxman, Leyden, 1875. — TR.
CH. vi] ON HUMAN UNDERSTANDING 347
mation. Perhaps some one will arise who will maintain that,,
although the soul can come only from one sex, both sexes
furnish something of the organism, and that from the two
bodies one is made, just as we see that the silk-worm is as it
were a double animal, and encloses a flying insect under the
form of the caterpillar : in such darkness are we still upon so
important a point. Some day perhaps the analogy of plants
will give us some light, but at present we have but little in
formation regarding the generation of plants themselves, the
surmise concerning the pollen which has been remarked, as
that which might correspond to the^ masculine semen, not
yet being very clear. Besides a slip of a plant is very often
capable of giving a new and complete plant, to which no
analogy is as yet seen in animals ; also we cannot say that
the foot of an animal is an animal, as each branch of the tree
seems to be a plant capable of fruit-bearing by itself. Fur
thermore the intermixture of species, and even the changes
in one and the same species often go on with much success
in plants. Perhaps at some time or place in the universe
the species of animals are, or were, or will be more subject
to change than they are at present with us, and many animals
who have somewhat of the cat, as the lion, the tiger, and the
lynx, might have been of one and the same race and may now
be as it were new subdivisions of the ancient species of cats.
Thus I always return to what I have more than once said that
our determinations of physical species are provisional and
proportional to our knowledge.1
§ 24. Ph. Men at least in making their divisions of species
have never thought of substantial forms, save those who, in
this single comer of the world where we are, have learned the
language of our schools.
Th. It seems that lately the term substantial forms has
come into disrepute with certain classes and that they are
ashamed to speak of them. Meanwhile there is perhaps in
that circumstance more of fashion than of reason. The scho
lastics employed inaptly a general notion, when they used it
to explain particular phenomena ; but this abuse does not de
stroy the thing. The soul of man is a little disconcerting to
1 Leibnitz here touches upon the theory of evolution, or development, hut
keeps himself within very moderate limits in the statement of his views. - TR.
348 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
the dogmatism of some of our moderns. There are some who
admit that it is the form of man ; but they also affirm that it
is the only substantial form of known nature. Descartes thus
speaks of it, and he censures Regius1 because he contested this
quality of a substantial form of the soul and denied that man
was a unnm per se, a being endowed with a veritable unity.2
Some think that this excellent man did this as a matter of
policy. I doubt this a little because I think he had reason
for so doing. But this privilege is not given to man only, as if
nature were made of broken sticks. There is room for the
judgment that there is an infinite number of souls, or, to speak
more generally, of primitive entelechies, which have something
analogous to perception and appetite, and which are all, and
remain always, substantial forms of bodies. It is true that
species apparently exist which are not truly a unum per se (i.e.
bodies endowed with a veritable unity, or with an invisible
essence which makes their entire active principle), any more
than a mill or watch might be. The salts, the minerals, and
the metals may be of this nature, i.e. simple contextures or
masses in which there is a certain regularity. But the bodies
of both, i.e. animate bodies as well as the contextures without
life will be specified by their internal structure, since in those
indeed which are animate, the soul and the machine,3 each by
1 Pierre Sylvain Regis— Latin, Regius — 1632-1707, a celebrated Cartesian,
at first destined for the church, but who, on going to Paris to study theology
at the Sorbonne, heard Rohault (cf. ante, p. 233, note 2) on Cartesianism,
became a zealous adherent of the doctrine, renounced the priesthood, and gave
himself up to teaching the new philosophy. His enormous success aroused the
opposition of Harlay, the Archbishop of Paris, who forbade his teaching. He
therefore turned to composition, expounding his philosophical ideas in his
Cours entier dc philosophic, or Systeme general selon lev principes de Des
cartes, 4 vols., 4to, Paris, 1(590, 2d ed., 3 vols., Amsterdam, 1691. He inter
preted Descartes in the sense of empiricism, and thus drew upon himself the
philosopher's censure, cf. Descartes, Remarks on the Programme of Regius,
Work*, ed. Cousin, Paris, 1824-26, Vol. 10, pp. 70-111; see also Veitch, The
Method, Meditations (tnd Selections from the Principles of Descartes, 8th ed.,
Edinburgh, 1881, pp. 278, 287. His doctrines were a reaction against the ultra
idealism of Malebranche. Other works of his are Response a la censura
philosophise cartesiante, 12ino, Paris, 1691; L' Usage de la Raison et dc la Foi,
4to, Paris, 1704. — TR.
2 Cf. Descartes, 1596-1650, JKpi»t.t L, 89, pp. 292-293, ed. of 1668, p. 261, ed.
of 1692, Cousin's ed., Vol. 8, pp. 579-583; Gerhardt, Leibniz, philos. Schrift.,
6,547, 550.ST/.— TR.
3 I.e. body, according to the linguistic usage of the Cartesians. — TR.
CH. vi] ON HUMAN UNDERSTANDING 349
itself, suffice for the determination ; for they agree perfectly,
and although having no immediate influence the one upon the
other, they are mutually expressive, the one having concen
trated into a perfect unity all that the other has dispersed in
the manifold. Thus, when the arrangement of species is the
question, it is useless to dispute about the substantial forms,
although it may be well for other reasons to know if there are
any and what their nature is ; for without this one would be a
stranger in the intellectual world. For the rest the Greeks
and the Arabians have spoken of these forms as well as the
Europeans, and if the common people do not speak of them,
no more do they speak of algebra or of surds.1
§ 25. Ph. Languages were formed before the sciences, and
ignorant and unlettered people reduced things to certain
species.
1 The doctrine of the substantial forms, of which the Mediaeval schoolmen
made so much use, finds its origin and point of departure in the eZ6o? and ovaia
of Plato and Aristotle. Aristotle used ova-ia in two senses ; in its primary and
proper signification, as a concrete and individual substance, a compound
Ovi/oAoiO of matter ({iAr;) and the determining principle, form (e!8os), in which
sense individual things were called "first substances" (rcpurai ova-inn ) ; sec
ondly, as applied to the genus, in which sense species were called " second
substances" (Sevrepai ouo-i'ai). According as they were nominalists or realists,
the Schoolmen, in their interpretation of Aristotle, regarded the substantial
forms as mere concepts of genus and species, the product of the abstraction-
power of the mind, which might correspond to, though they did not constitute,
the reality of tilings; or, as real universals existing in concrete things, consti
tuting their inmost essence and determining its nature. Locke adopts the
nominalistic view of these forms as purely subjective having no corresponding
reality in nature. Leibnitz maintains them in the realistic, sense as expres
sions of the reality of the " first substances," and in direct connection with
them develops his doctrine of monads. Cf. DIM-OUTS de Metaphys., 1080, § 10
sq.. Gerhardt, 4, 443; fy/sterne noureax, 1095, §§ 3, 4, 11, G. 4, 478 sq. (also
ibid, first draft, G. 4, 473), Erdmann, 124, Jacques, 1, 470, trans. Duncan,
PJiilos. Wk*. of Leibnitz. 72; De ipsa nnturn, 1098, §§ 11, 12, G. 4, 510, E. 157,
J. 1, 402, D. 120; also G. Hartenstein, Ueber Leibniz's Lc.hr e v. d. Verhaltniss
d. Monaden z. Korperwelt, in his Histor. philos. AbhandL, Leipzig, 1870, 409
sq., Stein, Leibniz u. Spinoza, Berlin, 1890. 158 sq., Dillmann, Eine n. Darstr/.
d. Leibniz. Monadenlehre, Leipzig, 1891, 225 sq. For Leibnitz's theological
use of Aristotle's forms — el&y — ef. Theodicee, Ft. III., §§ 335-0, and J. H. v.
Kirchmann's note 240 thereto, Band 80, p. 133, and note 02 f., Bd. 82, p. 87, of
his Philos. Bibliothek. Leipzig, 1879. On the eI6o? and oixria of Plato and Aris
totle, ff. Wallace, Outlines of the Philos. of Aristotle, §§ 10, 31, 32, 34, 37, and
Zeller, Philos. d. Griech.,IL,\ [Vol.3], 058 sq., 4th ed. 1889, II. 2 [Vol. 4], 304
sq., 3d ed., 1879. For the Scholastic doctrine, cf. B. Haureau, Histoire de la
philos. seholastique, 2d ed., Paris, 1872-80; A. Stockl, Gesrh. d. Philos. d.
Mittelfdters, Mainz, 1802-00; C. Prantl, Gesch. d. Lor/ik im Abendlande, Leip
zig, 1855-1870, passim. Cf. also G. 1, 10, 22 sq. , 4, 208.— TR.
350 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
Tli. True, but persons who study these matters rectify the
popular notions. Assayers have found exact means of dis
cerning and separating the metals ; botanists have enriched
wonderfully the doctrine of plants, and the experiments made
upon insects have opened for us a new path in the knowledge
of animals, but we are still very far distant from the half of
our course.
§ 26. Ph. If species were a work of nature they could not
be conceived so differently by different persons. Man appears
to one person an animal without feathers, with two feet and
with large nails, and another after a more profound exami
nation adds to these reason. Many people, however, deter
mine the species of animals by their external form rather than
by their birth, since the question has been put more than once
whether certain human foetuses should be admitted to baptism or
not, for the sole reason that their external configuration differed
from the ordinary form of infants, without knowing whether
they were not as capable of reason as infants cast in another
mould, some of whom are found, who, although of an approved
form, are never able to exhibit during their entire life as much
reason as appears in an ape or elephant, and who never give
any indication of being governed by a rational soul. Whence
it appears evident that the external form which alone has
found mention, and not the faculty of reasoning which no one
could know would be wanting in its time, has been regarded
essential to the human species. And in these circumstances
theologians and jurisconsults the most learned have been
compelled to renounce their sacred definition of rational
animal, and to put in its place some other essence of the
human species. "Mr. Menage," (Menagiana Tom. I. p. 278,
of the Dutch edition of 1G94,)1 " furnishes us the example of a
certain abbot of St. Martin, which deserves to be related.
When this abbot of St. Martin, he says, came into the world,
he had so little the figure of a man, that lie resembled rather
a monster. For some time they deliberated whether he
should be baptized, lie was baptized however, and declared a
man provisionally, i.e. till time should show what he was. He
1 M'e/Hif/icm't sivc cv.ccrpta ex ore ^n'xlii Mrnnr/u, 1st ed., 1 vol., 12mo,
Paris, K503, 3d ed., enlarged and corrected by La Monnoye, Paris, 1715. ]•><!-
maim, Jacques, and Schaarschmidt in his German trans, erroneously read l(!4-!>.
— TR.
CH. vij ON HUMAN UNDERSTANDING 351
was so disfigured by nature, that they called him all his life
the Abbot Malotru. He was of Caen." There Avas a child
who came very near being excluded from the human species
simply because of his shape. He narrowly escaped as it was,
and it is certain that a figure a little more deformed would
have deprived him of it for ever and have caused him to
perish as a being Avho ought not to pass for a man. Yet no
reason can be given why a rational soul could not have been
lodged in him, if the lineaments of his face had been a little
more altered ; why a visage a little longer, or a flatter nose, or
a wider mouth could not have subsisted as well as the rest of
the irregular figure with a soul and with qualities which made
him capable, wholly disfigured as he was, of being clothed
with dignity in the church.
Th. Up to the present time, no rational animal has been
found with an external figure very different from ours, there
fore, when the question arose of baptizing a child, race and
figure have always been considered only as marks by which to
judge whether it was a rational animal or not. Thus theo
logians and jurisconsults have never needed to renounce for
that reason their sacred definition.
§ 27. Ph. But if that monster, of which Licetus,1 Bk. I.,
chap. 3, speaks, with a man's head and a hog's body, or other
monsters, with the heads of dogs and of horses, etc., upon the
bodies of men had lived and could have spoken, the difficulty
would be much greater.
1 Fortunio Liceti, 1577-1057, a celebrated Italian physician and scholar, who
taught logic at Pisa, 1600-1(509 ; philosophy at Padua till 1631 ; then philosophy
at Bologna; and finally, theoretic medicine at Padua from 164-5 till his death.
He was a great admirer of Aristotle, and wished to admit nothing beyond his
doctrines, and thus contributed to render both philosophy and medicine sta
tionary. For the matter to which Leibnitz here refers, >•/. Licetus, De spontanco
viventixm ortn, lib. quat., fol., Vicentire, 1(518, Bk. I., chap. 28, pp. 34-36, Sexta
coniirmatio spontanei ortus hominum petita ex humanis tiguris in bclluis, ac
lapidibus enodatnr aperiendo talium rigurarum caussas, in which chapter
Licetus treats of various monsters, referring to his De monstrorum mentioned
below, and to his father's, Giuseppe Liceti, an Italian physician, died 1599,
Di<dof/us de gcnitalium nsu e,t diynitate, or II Ceca, dell' ouvero eceellenza cd
UKO <!<'' r/enitrdi, 1598, DC monstrorum orwss/.s, tuitura, et differentiis lib. duo,
2d ed., 4to, Petavii, 1634, pp. 13, 183, 194 : " I)e monstrorum humanorum reale
existent-ire"; the same, with additions by (lerard Blasius, 4to, Amstelodami,
16(55, pp. 13, 183, 194; the same, in the French trans., Traite den monxtres, by
Jean Palfyn, 1(550-1730, in his Description anatomique dex parties de lafemme
qui sercent a la generation, etc., 4to, Leyden, 1708, pp. 13, 197, 208. — TR.
352 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
Th. I admit it, and if that occurred and if any one had done,
as a certain writer, a monk of the olden time, named Hans
Kalb (Jean le veau — John the calf) who l painted himself
with a calf's head, the pen in his hand, in a book he had
written, which procedure caused some foolishly to think that
this writer had in reality a calf's head, — if, I say, that hap
pened, we should be more cautious hereafter in getting rid of
monsters. For there is some probability that reason would
maintain it with theologians and with jurisconsults in spite of
the figure and even in spite of the differences which the
anatomy would furnish to the physicians, which would as
little injure the quality of man as the reversal of the viscera
in that man whose anatomy some persons of my acquaintance
have seen at Paris, which has made some stir, in which nature
" Feu sage et sans doute en debauche
Plac,a le foye au coste gauche
Et de meme vice versa
Le coeur a la droite pla^a,"
i.e. "unwise and doubtless in debauch placed the liver upon the
left side and likewise vice versa the heart upon the right,"
if I rightly remember some of the verses which the late Mr.
Alliot2 the father (a famous physician because he passed as
skilful in the treatment of cancers) showed me of his own
making upon this prodigy. It is a matter of course, provided
the variety of conformation does not go too far in the case
of rational animals and that no return is made to the times
when animals spoke, for then we should lose our especially
peculiar advantage of reason 3 and should henceforth be more
attentive to birth and the external in order to be able to dis-
1 Erdmann and Jacques add " qui " after " le veau." — TR.
2 Pierre Alliot, a French physician of the seventeenth century, born at
Bar-le-Duc, reputed to have great skill in the treatment of cancer and other
malignant ulcers. His most distinguished patient was Anne of Austria, the
mother of Louis XIV., whom he treated unsuccessfully in Paris in 1065. Not
withstanding his failure, he was appointed physician to the king. His published
works include Theses medicse de tnotii sanguinis circulate et de m orb is ex sere,
Pont-a-Mousson, 1663, 8vo; Epistola de cancro apparente, and Nuntius profli-
gati sine ferro et igne carcinomatis, hoth Bar-le-Duc, 1664, 12mo. His son,
Jean Baptiste Alliot, was physician to Louis XIV., and published Traite du
cancer ou Von expliqne sa nature et ou Von propose les moyens les plus surs
pour le guerir methodiquement, Paris, 1698, 12mo. — TR.
3 The French text is : " nostre privilege de la raison en preciput," etc. — TR.
CH. vi] ON HUMAN UNDERSTANDING 353
cern those of Adam's race from those who may descend from
a king or patriarch of some canton of apes in Africa; and our
learned author was right in his remark (§ 29) that if Balaam's
ass had all her life discoursed as rationally as she did once
with her master (supposing it was a prophetic vision), she
would always have had difficulty in obtaining rank and a seat
among women.
Ph. You laugh, I see, and perhaps the author laughed also ;
but, to speak seriously, you see that you cannot always assign
fixed limits to species.
Th. I have already agreed to this ; for when the question
concerns fictions and the possibility of things, the passage
from species to species may be insensible, and to discern them
would sometimes be about as impossible as to decide how
much hair a man must be allowed that he may not be bald.
This indeterminateness would be true even when we knew
perfectly the internal nature of the creatures under discussion.
But I do not see that it can prevent things from having real
essences independent of the understanding, and us from know
ing them. It is true that the names and limits of species
would sometimes be like the names of measures and weights,
where choice is necessary in order to have fixed limits. But
ordinarily there is nothing of the kind to fear, species too
much alike seldom occurring together.
§ 28. Ph. It seems we agree here at bottom, although we
differ somewhat in terms. I also admit that there is less
arbitrariness in the denomination of substances than in the
names of the mixed modes. For few venture to unite the
bleating of a sheep with the figure of a horse, or the color of
lead with the weight and fixedness of gold, and we prefer to
draw copies after nature.1
Th. This is not so much because in substances regard is
had only to that which exists effectively, as because there is no
certainty in the case of physical ideas (which are not very
thoroughly understood) that their union is possible and useful,
if there is no actual existence to guarantee it. But this also
takes place in the modes, not only when their obscurity is
impenetrable by us, as sometimes happens in physics, but also
1 That is, to follow experience in the formation of our ideas, and to conform
our inner world in general to that furnished by nature. — TR.
2A
354 LEIBNITZ'S CEITIQUE OF LOCKE [BK. in
when it is difficult of penetration, enough examples of which
occur in geometry. For in both of these sciences it is not
within our power to make combinations according to our fancy,
otherwise we should be right in speaking of regular decahedrons,
and should seek in the semicircle1 a centre of magnitude, as
there is in it a centre of gravity. For it is in fact surprising
that the first is there, and that the second cannot be. Now
while in the modes the combinations are not always arbitrary,
we find -on the other hand that in substances they sometimes
are so ; and it often depends on ourselves to make combina
tions of qualities in order further to define substantial beings
in advance of experience, when we understand enough of these
qualities to judge of the possibility of the combination. Thus
it is that expert gardeners in the orangery can rationally and
successfully propose to produce some new species and give it
a name in advance.
§ 29. Ph. You will always agree with me that when the
question arises of defining species, the number of ideas com
bined depends upon the different application, industry, or fancy
of the one forming this combination, as it is the figure which
regulates most frequently the determination of the species of
vegetables or animals, and likewise as regards the majority, of
natural bodies which are not produced by seeds, it is the color
which is most strongly adhered to. § 30. In truth these are
often only confused conceptions, gross and inexact, and it is
very essential that men agree as to the precise number of
simple ideas or qualities which belong to a given species or a
given name, for pains, skill, and time are needed to find simple
ideas which are constantly united. However a few of the
qualities composing these inexact definitions are ordinarily
sufficient in conversation ; but in spite of the stir about gen
era and species, the forms, of which so much has been said in
the schools, are only chimeras which avail us nothing in fur
nishing an entrance into the knowledge of specific natures.
Th. Whoever makes a possible combination, is not at all
mistaken therein, nor in giving it a name ; but he is mistaken
1 Such combinations of essentially self-contradictory ideas may easily be
united in a complex term, and be apparently clear and possible, until analyzed
and compared with reality, when their confusion and impossibility is at once
made evident. — TR.
en. vi] ON HUMAN UNDERSTANDING 355
if he thinks that his conception is altogether that which others
more expert have conceived under the same name or in the
same body. He perhaps conceives a genus too common instead
of another more specific. There is nothing in all this contrary
to the schools, and I do not see why you return here to the
charge against genera, species, and forms, since it is necessary
for you to recognize indeed the genera, species, and even the
internal essences or forms, which we do not pretend to employ
in order to know the specific nature of the thing, although we
admit we are still ignorant of them.
§ 30. Ph. It is at least evident that the limits we assign to
species are not exactly conformed to those established by nature.
For in our need of general names for present use, we do not
put ourselves to the trouble of discovering the qualities which
would give us superior knowledge of their most essential dif
ferences and agreements, but we ourselves distinguish them
into species in virtue of certain appearances which are mani
fest to everybody, that we may more easily communicate with
others.
Th. If we combine compatible ideas, the limits we assign to
species are always exactly conformed to nature ; and if we are
careful to combine ideas actually found together, our notions
are also conformed to experience; and if we consider them
as provisional only for actual bodies, without excluding ex
periment made or to be made for further discovery therein,
and if we have recourse to experts, when a definite question
arises with reference to what is openly understood by the
name, we shall not err in the matter. Thus nature may
furnish ideas the most perfect and most convenient, but she
will not give the lie to those we have which are good and
natural, although not perhaps the best and most natural.
§ 32. Ph. Our generic ideas of substances, as that of metal,
for example, do not follow exactly the models set them by
nature, since you cannot find any body including simply malle
ability and fusibility without other qualities.
Th. No one asks for such models and it would not be reason
able to ask for them ; furthermore they do not occur in the
most distinct notions. We never find a number in which there
is nothing to notice but multitude in general, an extension in
which there is only extension, a body in which there is only
356 LEIBNITZ'S CRITIQUE OF LOCKE [BK. m
solidity, and no other qualities ; and when the specific differ
ences are positive and contrary it is very essential that the
genus share in them.
Ph. If, then, any one thinks that a man, a horse, an animal,
a plant, etc., are distinguished by real essences made by nature,
he must think that nature is very liberal icith these real essences,
if she produces one of them for the body, another for the
animal, and still another for the horse, and that she bestows
freely all these essences upon Bucephalus ; whilst genera and
species are only signs more or less comprehensive.
Th. If you take real essences as these substantial models,
which exist as a body and nothing more, an animal and nothing
more specific, a horse without individual qualities, you are
right in treating them as chimeras. And no one has main
tained, I think, not even the greatest Realists of former times,
that there are as many substances confining themselves to the
generic as there are genera. But it does not follow that if
general essences are not this, they are merely signs; for I have
many times remarked to you that there are possibilities in the
resemblances. In like manner from the fact that colors are not
always substances or extracted dyes, it does not follow that
they are imaginary. For the rest you cannot think nature too
liberal ; she is so beyond all that we can invent, and all advan
tageous compatible possibilities are found realized upon the
grand theatre of her representations. There were formerly
two axioms among philosophers : that of the Realists seemed
to make nature prodigal, and that of the Nominalists seemed
to declare her stingy. The one says that nature suffers no
vacuum, and the other that she does nothing in vain. These
two axioms are good provided you understand them ; for nature
is like a good economist, who saves where it is necessary in
order to be grand at times and places. She is grand in effects,
and sparing in the causes she employs.
§ 34. Ph. Without amusing ourselves longer with this dis
cussion upon real essences, it is enough that we obtain the pur
pose of language and the usage of words which is to indicate
our thoughts in an abridged form. If I wish to speak to any
one of a species of birds three or four feet in height, whose
skin is covered with something between feathers and hair, of a
dark brown color, without wings, but in their place two or
CH. vi] ON HUMAN UNDERSTANDING 357
three small branches, like those of the broom, which descend
to the lower part of the body, with long and large legs, the
feet armed only with three claws and without a tail 5 I am
compelled to make this description whereby I can make myself
understood by others. But when I am told that the name of
this animal is Cassowary, I can then use this name to designate
in discourse this entire complex idea.
Th. Perhaps a very exact idea of the covering of the skin
or of some other part would suffice by itself alone to distin
guish this animal from every other known, as Hercules was
known by his gait, and as the lion was recognized by his claw
according to the Latin proverb. But the more circumstances
you heap up, the less provisional is your definition.
§ 35. Ph. We may curtail the idea in this case without
prejudice to the thing; but when nature curtails it, it is a
question whether the species remains. For example : if a
body existed having all the qualities of gold except mallea
bility, would it be gold ? it depends upon men to decide.
They are then the ones who determine the species of things.
Th. Xot at all ; they would determine only the name. But
this experience would teach us that malleability has no neces
sary connection with the other qualities of gold taken together.
It would teach us then a new possibility and consequently a
new species. As for gold which is eager 1 or brittle, this comes
only from additions, and is not consistent with the other tests
of gold ; for the cupel and antimony remove this eagerness
from it.
§ 36. Ph. A portion of our doctrine follows that will appear
very strange. Each abstract idea having a certain name forms
a distinct species. But what of that, if nature so wills it ? I
should be glad to know why a lap-dog and a greyhound are not
as distinct species as a spaniel and an elephant.
Th. I have distinguished above the different senses of the
word spedes. Taking it logically, or mathematically rather,
the least dissimilitude may suffice. Thus each different idea
will give another species, and it makes no difference whether
it has a name or not. But, physically speaking, we do not at
tend to all the varieties, and we speak either distinctly when the
question concerns only appearances, or conjecturally when the
1 Cf. Locke, Philos. Works, Vol. 2, p. (>5 (Bolm's ed.). — TR.
358 LEIBNITZ'S CRITIQUE OF LOCKE [UK. in
question concerns the inner truth of things, presuming therein
some essential and immutable nature, like reason in man.
We presume then, that whatever differs only by accidental
changes, like water and ice, quicksilver in the liquid form and
as sublimate, is of the same species : and in organic bodies the
provisional mark of the same species is usually placed in the
generation or race, as in those most alike it is placed in repro
duction. It is true we cannot judge with precision, for lack
of knowledge of the inner nature of things : but, as I have
said more than once, we judge provisionally and often con-
jecturally. But when we wish to speak only from the external,
for fear of saying nothing certain, there is some latitude ; and
to dispute then whether a difference is specific or not is to
dispute about the name ; and in this sense there is so great a
difference between dogs, that we may very well say that the
house-dogs of England and the dogs of Boulogne belong to
different species. It is not impossible, however, that they
belong to a remote identical or similar race, which we should
find if we could go back very far, and that their ancestors
were alike or identical, but that after great changes, some of
the posterity have become very large and others very small.
We may indeed believe also without offending reason that
they have in common an inner nature, constant, specific, which
is no longer subdivided thus, or which is not found here in
several other such natures, and consequently is no longer
varied save by accidents ; although there is also nothing to make
us judge that this must necessarily be so in all that which we
call the lowest species (species infima). But there is no likeli
hood that a spaniel and an elephant are of the same race, and
that they have such a specific common nature. Thus in the
different sorts of dogs, speaking of appearances, we may dis
tinguish species, and speaking of the inner essence we may be in
suspense : but comparing the dog and the elephant there is no
reason for attributing to them externally or internally that
which would make us think them of one and the same species.
So there is in this case no occasion for suspense in the face of
the presumption. In man we can also distinguish species
logically speaking, and if we stopped with the external we
should find also, speaking physically, differences which could
pass as specific. Thus a traveller was found who thought
en. vi] ON HUMAN UNDERSTANDING 359
that the Negroes, Chinese, and finally the Americans were not
of one and the same race among themselves nor with the
peoples resembling us. But as we know the essential inner
nature of man, i.e. the reason, which dwells in the man him
self and is found in all men, and as we notice nothing fixed
and internal among us which forms a subdivision, we have no
reason to judge that there is in men, according to the truth of
the inner nature, an essential specific difference, while such
difference is found between man and beast, supposing that the
beasts are only empirical, according as I have explained above,
as in fact experience gives us no reason for forming any other
judgment.
§ 39. Ph. Let us take the example of an artificial thing
whose internal structure is known to us. A time-piece that
only indicates the hours, and one that strikes, are of one
species only for those who have only one name by which to
designate them ; but for him who designates the first by the
name watch, and second dock, they are in relation to him dif
ferent species. It is the name and not the inner disposition
which makes a new species, otherwise there would be too
many species. There are watches with four wheels, and
others with five ; some have strings and fusees,1 and some not ;
some have a free balance, and others are regulated by a spiral
spring and others by hog's bristles. Does any one of these
things suffice to make a specific difference ? I say no, so
long as these time-pieces agree in name.
Th. And I for my part say yes, for without stopping at
names, I should consider the varieties of contrivance and
especially the differences of the balance ; for since a spring
has been applied which governs the vibrations according to
its own and consequently renders them more equal, pocket-
watches have changed their character, and have become in
comparably more accurate. I have indeed mentioned before
another principle of equality which might be applied to
watches.
Ph. If any one wishes to make divisions based upon the
differences which he knows in the internal configuration he
may do so; but they would not "be distinct species with rela
tion to the people who are ignorant of this construction.
1 Locke has "physies," Philos. Works, Vol. 2, p. 07 (Bohn's ed.). — TR.
360 LEIBNITZ'S CRITIQUE OF LOCKE [BK. m
Th. I do not know why those with you always wish to
make virtues, truths, and species depend upon our opinion or
knowledge. They exist in nature, whether we know it and
approve or not. To speak otherwise is to change the names
of things and received language without any reason. Men up
to the present time have believed that there are many kinds
of clocks or watches, without informing themselves in what
they consist or how they may name them.
Ph. You have however recognized not long since that when
men wish to distinguish physical species by appearances, they
limit them in an arbitrary way, where they find it to the pur
pose, i.e. according as they find the difference more or less
considerable and according to the end they have. And you
yourself have made use of the comparison of weights and
measures, which are regulated and given their names accord
ing to the good pleasure of man.
Th. It is since then that I have begun to understand you.
Between specific differences purely logical, for which the least
variation of assignable definition suffices, however accidental
it be, and between specific differences purely physical, based
upon the essential or immutable, we may place a mean, which
cannot be precisely determined ; it is regulated by the most
important appearances, which are not altogether immutable,
but which do not change easily, the one approaching the
essential more than the other. And as a connoisseur too may
go farther than another, the thing appears arbitrary and has
some relation to men, and it appears convenient to regulate
names also according to these principal differences. We can
then speak thus, that there are specific civil differences and
nominal species which must not be confounded with what I
have called above nominal definitions, and which have place
in differences specifically logical as well as physical. For the
rest, besides common usage, the laws themselves may give
authority to the significations of words, and then the species
would become legal, as in the contracts which are called
nominati, i.e., designated by a particular name. For example
as the Roman Law made the age of puberty commence at the
end of the fourteenth year. This entire consideration is not
to be despised, but I do not see that it is of very much use
here, for besides the fact that you have appeared to me to
CH. vi] ON HUMAN UNDERSTANDING 361
apply it sometimes where it did not apply, we shall accom
plish nearly the same result if we consider that it rests with
men to proceed in subdivisions as far as they find them to
the purpose, and to abstract ulterior differences without the
necessity of denying them ; and that it also rests with them
to choose the certain, notwithstanding the uncertain, in order
to fix some notions and measures by giving them names.
Ph. I am much pleased that we are here no longer so far
apart as we appeared. § 41. You agree then, sir, I see, that
artificial as well as natural things are species contrary to the
view of some philosophers. § 42. But before leaving the
names of substances, I would add that of all the diverse ideas
we have, they alone are ideas of substances which have proper
or individual names ; for it rarely happens that men need to
make frequent mention of any individual quality or other
individual accident. Besides individual acts perish at once
and the combination of circumstances which thereby comes
about only subsists as in the substances.
Tli. There are, however, cases where it has been necessary
to remember an individual accident and to give it a name ;
thus your rule is ordinarily good, but there are exceptions to
it. Religion furnishes us with them ; for example we cele
brate each year the memory of the birth of Jesus Christ. The
Greeks call this event Theogeny, and that of the adoration of
the Magi, Epiphany. And the Hebrews call the Passah par
excellence the passage of the angel who caused the death of
the eldest sons of the Egyptians without touching those of the
Hebrews ; and this is why they were to celebrate its memory
every year. As for the species of artificial things, the scholastic
philosophers found difficulty in admitting them into their pre
dicaments ; but there was little necessity for their hesitation
since these predicamental tables were destined for use in mak
ing a general review of our ideas. It is well however to rec
ognize the difference existing between perfect substances and
between the assemblages of substances (aggregata) which are
substantial entities composed either by nature or by the art of
man. For nature has also such aggregates, as the bodies whose
mixture is imperfect (imperfecte mixta) to use the language of
our philosophers, which constitute no unum per se and do not
possess in themselves a perfect unity. I believe however that
LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
the four bodies which they call elements, and think simple, and
the salts, metals, and other bodies which they think are per
fectly mixed, and to which they attribute their temperaments,1
are not unum per se either; so much the more as we must
judge that they are uniform and homogeneous only in appear
ance, and even a homogeneous body would not cease to be a
mass. In a word, the perfect unity must be reserved to bodies
animated, or endowed with primitive entelechies; for these
entelechies are analogous to souls and are as individual and
imperishable as they ; and I have elsewhere affirmed that their
organic bodies are practically machines, but which surpass the
artificial machines of our invention as much as the inventor of
the natural machines surpasses us. For these natural machines
are as imperishable as the souls themselves, and the animal
with the soul subsists always : it is (the better to explain my
self by something pleasing, wholly laughable as it is,) as if a
harlequin wished to strip himself in the theatre, but could not
succeed because he had an indefinite number of garments one
upon another ; although these infinite replications of organic
bodies, which exist in an animal, are not so similar nor so
applied the one to the other, as the garments, nature's art
being of a wholly different subtility. All this shows that the
philosophers have not been wholly in the wrong in putting so
great distance between artificial things and between natural
bodies endowed with a real unity. But it belonged only to
our time to develop this mystery and make understood its
importance and consequences in order thoroughly to establish
natural theology and what is called Pneumatics,- in a manner
1 Leibnitz here alludes to the four elements of Empedocles, c. 492-c. 4-32,
B. c., viz., tire, air, earth, water, adopted by Plato and Aristotle and called by
the Peripatetics warmth, cold, dry ness, humidity, a mixture of which in vary
ing proportions constituted all bodies. Cf. Zeller, Philox. <l. Gricc.. I. 2 [Vol.
2], 758 (tq., 5th eel., 1892, II. 1 [Vol. ,'j], 796 sq., 4th ed., 1889, II, 2 [Vol. 4]. 4.°»1,
f<q., 8:52 *f/., :>d ed., 1879. The state of a body resulting from the proportional
disposition of these primary constituent elements or qualities was called its
temperament, the character of the temperament varying according to the pre
dominance of one or more of the elements. The scholastics discussed the
question whether the temperament comprised these four primary qualities, or
whether it did not consist in a fifth simple quality, the outcome of the recipro
cal action of the four primary qualities, which resulted in their entire destruc
tion. Cf. also (-jrerli&rdt, Leibniz. ]>}ii!ox. X<-1irift., 4. 207. — TK.
2 Cf. ant<>, p. 50, note 2. Schaarschmidt states that Pneumatics — Pneumatik
— with the meaning — Doctrine of the Spirit, Lchre vom Geiste — Psychology
en. vi] ON HUMAN UNDERSTANDING
truly natural and in agreement with our experiments and
understanding, and requiring the loss of none of the important
considerations they are destined to furnish, or rather enhanc
ing their value, as does the system of pre-established harmony.1
And I believe that we can best conclude this long discussion
of the names of substances only by that means.
— occurs in Alsted's Encyclop&die, Herborniae, 1630, cf. ante, p. 311, note 2, and
that Stephen Chauvin in his Lexicon philosophicum, Leovardiae, 1713, adopted
it and explained it by Pnenmatology and Pneumatosophy. The term is now
confined to physical science, and denotes that department of hydrodynamics
which treats of the properties of gases as distinguished from liquids. Cf.
Krauth-Flemming, Vocab. of the Philos. Sciences, p. 388, New York, Sheldon
& Co., 1883. — TR.
1 Cf. Neio Essays, Bk. IV., chap. 10, §§ 7 and 9, infra, pp. .505, 507 ; Sj/steme
nouveau, §§ 14-16, Gerhardt, 4, 484-86, Erdmann, 127, a-128, Jacques, 1, 475-77,
trans. Duncan, Philos. Wks. of Leibnitz, 77-79 ; Considerations sur lea principes
de vie, etc., G. 6, 541, E. 4:50, trans. D. 165; Principes de la nature et de In
grace, §§ 7-13, G. (5, 602-604, E. 71(5. trans D. 212-215; Animadrersioncs in
partem generalem Principiorum Cartesianorum, Pt. I. ad Art. 14, G. 4, .".58,
trans. D. 50; Leibniz gcgen Descartes and den Cartesianismtts, G. 4, 292-294,
401-403, 405-406, E. 176, trans. D. 132-138, and his note 49, p. 382; Med. dc Cog.
Ver. et Ideis, G. 4, 424, E. 80, a, trans. D. 30. According to Leibnitz, his
doctrine of monads requires as its necessary complement the existence- of God,
since the single monads, expressing in their own experience all that is beyond
them, yet without influence on other monads, cannot furnish a sufficient
ground or reason for the harmony and connection of tilings in a universal
world-order. This harmonious world-order existing, its sufficient ground or
reason must be found in the absolute being, God, who has given to each
monad the nature which makes it capable of developing itself in its extreme
individuality in accord and correspondence with every other. The pre-estab
lished harmony is thus an actual proof, in accord with experience, of the
existence of God, and the suggestion of reason in the ontological argument as
improved by Leibnitz, is confirmed by the comparative and comprehensive
study of the phenomena of nature. For expositions and criticisms of Leibnitz's
doctrine, cf. Dawey, Leibniz's A>/y; Essai/s, chaps. 11, 12; E. Zeller, Gesch*d.
deutschen Philns. seit .Leibniz, 2d ed., Munchen, 1875, pp. 88-98, 124-127; F. A.
Lange, GescJi,. d. Materialismus, 3d ed., Leipzig u. Gerlohn, 1875 #•'/., Bk. I.,
Sect. IV., chap. 4, Eng. trans, by E. C. Thomas, 3 vols., Boston, Vol. 2, pp.
124 sq. ,- Kuno Fischer, Gcvh. d. n. Philos., Bd. II., Leibniz, 3d ed., Heidelberg,
1889, pp. 455 sq., 539 sq. — TR.
364 LEIBNITZ'S CRITIQUE OF LOCKE [UK. in
CHAPTER VII
OF PARTICLES
§ 1. Ph. Besides the words which are used to name ideas, we
need those which signify the connection of ideas or proposi
tions. This is, this is not, are general signs of affirmation or
negation. But besides the parts of propositions the mind also
binds together sentences and entire propositions, § 2. availing
itself of words expressing this union of different affirmations
and negations and which are called particles; in whose proper
use the art of speaking well principally consists. It is in
order that reasoning be consecutive and methodical that terms
showing the connection, restriction, distinction, opposition, em
phasis, etc., are needed. And when they are despised the
hearer is embarrassed.
Tli. I admit that particles are very useful ; but I am not
aware that the art of speaking well consists principally in
their proper use. If any one presents only aphorisms or
detached theses, as they often do in the universities, or as in
the case of that which they call among the jurisconsults an
articulate libel, or as in the articles which are offered to the
witnesses, then provided we arrange these propositions well
we shall accomplish very nearly the same result in making
them understood as if we had put in the connective and the
particles ; for the reader supplies them. But I admit there
would be trouble if you put in the particles badly, and much
more than if you omitted them. Particles seem to me also
to unite not only the parts of discourse composed of proposi
tions and the parts of the proposition composed of ideas, but
also the parts of the idea, composed in many ways by the
combination of other ideas. And it is this last connection
which is indicated by the prepositions, while the adverbs
modify the affirmation or negation in the verb ; and the con
junctions modify the connection of different affirmations or
negations. But I doubt not that you have noticed all this
yourself, although your words seem to state otherwise.
§ 3. Ph. The part of grammar which treats of particles has
CH. vn] ON HUMAN UNDERSTANDING 365
been cultivated less than that which represents in order the
cases, genders, modes, tenses, gerundives, and supines. It is true
that in some languages they have also arranged the particles
under some titles by distinct subdivisions with great appear
ance of exactness. But it is not sufficient to run through
these catalogues. One must reflect upon his own thoughts in
order to observe the forms which the mind takes in discours
ing, for the particles are so many indications of the action of
the mind.
Tli. It is very true that the doctrine of the particles is
important, and I wish we might enter into much greater
detail thereupon. For nothing would be more suited to make
known the different forms of the understanding. Genders are
of no account in philosophical grammar, but the cases corre
spond to the prepositions, and often the preposition is enveloped
in the noun and as it were absorbed, and other particles are
concealed in the inflections of the verbs.
§ 4. Ph. In order properly to explain particles it is not
sufficient to render them (as is usual in a dictionary) by the
words of another language which approach most nearly their
meaning, because it is as difficult to comprehend their precise
meaning in one language as in another ; besides the significa
tions of related words in two languages are not always exactly
the same and indeed they vary in one and the same language.
I remember that in the Hebrew language there is one particle
of a single letter1 of which there are reckoned up more than
fifty significations.
Th. Scholars have attempted to make special treatises upon
the particles of the Latin, Greek, and Hebrew; and Strauchius,2
a celebrated jurisconsult, has published a book upon the use
of particles in jurisprudence, where their signification is of no
small consequence. We ordinarily find, however, that it is
rather by means of examples and synonymes that they attempt
to explain them, than by distinct notions. Further we can
1 I.e. the adverb b. — TR.
2 Johann Strauch, 1(U2-1(>80, the maternal uncle of Leibnitz, a distinguished
jurisconsult, Professor at Leipzig, Jena, and Giessen, and Syndicus in Braun
schweig; cf. Guhraner, G. W. Freiherr v. Leibnitz, Pt. I., Bk. I., pp. (5, 135 sq.,
and Anmerkunc/en z. erst. Buche, pp. (>, 7. The book here referred to by
Leibnitz is entitled: Lexicon par ticularum juris s. de usu et efficacia quor-
imdam syncategorematum et particalarum indeclinab ilium. — TR.
LEIBNITZ'S CRITIQUE OF LOCKE [HK. m
not always find a general or formal signification for them, as
the late Bohlius l called it, which can satisfy all the examples ;
but notwithstanding this we can always reduce all the uses of
a word to a definite number of significations. And this is
what should be done.
§ 5. Ph. In fact the number of significations greatly exceeds
that of the particles. In English the particle but has very differ
ent significations: (1) when I say: bat to say no more, (metis
pour ne. rien dire de plus) as if this particle indicated that the
mind stops in its course before it has reached the end. But
saying : (2) I saw but two planets (je vis seulement deux planetes),
the mind restricts the sense of what it means to that which
has been expressed by the exclusion of everything else. And
when I say (3) : you pray, but it is not that God would bring you
to the true religion, but that he ivould confirm you in your own
(vous priez Dieu mats ce n'est pas qu'il veuille vous ameiier a
la connaissance de la vraye Religion, ma-is qu'il vous confirms
dans la vostre), the first but (or mats) designates a supposition
in the mind which is otherwise than it should be, and the
second shows that the mind puts a direct opposition between
what precedes and what follows. (4) All animals have sense,
but a dog is an animal (tons les animaux out du sentiment,
mats le chien est un animal). Here the particle signifies the
connection of the second proposition with the first.
Th. The French mais (but) may be substituted in all these
instances except the second ; but the German allein, taken as
a particle, which signifies a kind of mixture of mais (.but) and
seulement (only), may doubtless be substituted instead of but
in all these examples except the last, where its use may be a
little doubtful. Mais (but) is also rendered in German some
times by aber, sometimes by sondern, which indicates a sepa
ration or segregation and approaches the particle allein. For
a proper explanation of the particles, it is not sufficient to
make an abstract explication as we have just made here ; but
we must proceed to a paraphrase which may be substituted in
1 Samuel Bohl, 1611-1689, Professor at Rostock, who devoted himself to the
furtherance of the study of Hebrew in Germany, and whom Leibnitz mentions
because of his works on the doctrine of the Hebrew Vowel- and Accent-Signs ;
cf. Dutens, Leibniz, op. om., 5, 190. He published a large number of works,
among which were Srrutin. S. s. ex accentibus, 1630, and Dissertat. pro for-
rnali Signif. S. S. eruenda, Rostock, 1637. — TR.
CH. vii] ON HUMAN UNDERSTANDING 367
its place, as the definition may be put in the place of the thing
defined. When we have striven to seek and to determine
these suitable paraphrases, in all the particles so far as they
are susceptible of them, we shall have regulated their sig
nifications. Let us try to attain this result in our four ex
amples. In the first we mean : Thus far only speak we of
this, and no farther (non piii) ; in the second : I see only two
planets, and no more ; in the third : You pray God, and for
this only, viz. to be confirmed in your religion, and no more,
etc. ; in the fourth, it is as if we said : all animals have sense ;
it is sufficient to consider that only, and no more is needed.
The dog is an animal, he then has sense. Thus all these
examples indicate limits, and a non pZws ultra, whether in
things, or in discourse. Thus but is an end, a limit of the
course, as if we said : stop, we are there, wre have reached our
Bat. But, Bute, is an old Teutonic word, signifying some
thing fixed, an abode. Beuten (an obsolete word found still in
some church songs) is to abide. Mais originates from magis,
as if any one wished to say : as for the surplus ice must leave it,
which is the same as saying : Xo more is needed, it is enough,
let- us come to something else, or this is something else. But
as the use of languages varies in a strange manner, it would be
necessary to enter much farther into the detail of examples in
order sufficiently to regulate the significations of particles. In
French Ave avoid the double mais by a cependant (however), and
we should say: Vous priez, cependant ce ii'est pas pour obtenir
la verite, mais pour estre confirme dans vostre opinion (You
pray, not however (cependant} to obtain the truth but (mais)
to be confirmed in your opinion). The sed of the Latins was
often expressed formerly by ains, which is the anzi of the
Italians, and the French in modifying it have deprived their
language of an advantageous expression. For example : There
was no certainty about it, yet (cependant) we were persuaded
of what I have informed you, because we like to believe
what we wish ; but it has been found that it was not so ; but
(ains) rather, etc. (II n'y avoit rien de seur, cependant on estoit
persuade de ce que je vous ay mande, parce qu'oii aime a croire
ce qu'on souhaite ; mais il s'est trouve que ce irestoit pas
cela; ains plustost, etc.).
§ 6. Ph. My purpose has been to touch this matter only
308 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
very slightly. I would add that particles often include either
constantly or in certain constructions the sense of an entire
proposition.
Tli. But when it is a complete sentiment, I think that it is
only by means of a kind of ellipsis ; otherwise it is the inter
jections alone which in my opinion can subsist by themselves
and say all in a word, as all! (hoi me!}. For when we say
mat's, adding nothing more, it is an ellipsis for : but let us icait
for the confirmation of intelligence and not natter ourselves
unduly. There is something approximating to tin's in the nisi
of the Latins : si nisi non esset, if there were not but (mats).
For the rest I should not be displeased, sir, had you entered a
little farther into the detail of the turns of the mind which
appear marvellous in the use of the particles. But since we
have reason for hastening to conclude this investigation of
words and to return to things, I do not wish to delay you
longer, although I truly think that languages are the best
mirrors of the human mind, and that an exact analysis of the
signification of words would show us better than anything else
the workings of the understanding.
CHAPTER VIII
OF ABSTRACT AND CONCRETE TERMS
§ 1. Ph. It is further to be remarked that terms are
abstract or concrete. Each abstract idea is distinct, so that of
two the one can never be the other. The mind must perceive
by its intuitive knowledge the difference between them, and
consequently two of these ideas can never be affirmed one of
another. Every one sees at once the falsehood of these propo
sitions : humanity is animality or rationality : this is as evident
as any of the generally received maxims.
Th. There is still something to be said thereupon. We
admit that justice is a virtue, a habit (habitus], a quality, an
accident, etc. Thus two abstract terms may be stated one of
another. I am furthermore wont to distinguish two kinds of
abstracts. There are abstract logical terms, and there are
also abstract real terms. The abstract real terms, or conceived
CH. ix] ON HUMAN UNDERSTANDING 369
at least as real, are either essences or parts of the essence, or
accidents, i.e. beings added to substance. The abstract logical
terms are the predications reduced to terms, as if I said : to be
a man, to be an animal; and in this sense the one can be
stated of the other, by saying : to be a man is to be an animal.
But in the realities this has no place. For we cannot say that
humanity or man-ness * (Vhommeite) — (if you please), which is
the essence of the whole man, is animality, which is only a
part of this essence ; yet these abstract and incomplete beings
signified by the abstract real terms have also their genera and
species which are not less expressed by the abstract real terms :
thus there is predication between them, as I have shown by
the example of justice and virtue.
§ 2. Ph. One may always say that substances have only
few abstract names ; they have scarcely spoken in the schools
of humanity, animality, corporality ; and they have never been
authorized in the world.
Th. The reason is that but few of these terms were necessary
to serve as examples and to throw light upon the general no
tion, which was the reason why they were not wholly neglected.
If the ancients did not use the word humanity in the sense of
the schools, they said human nature, which is the same thing.
It is certain also that they said divinity, or rather divine
nature ; and theologians having found it needful to speak of
these two natures and of real accidents, they were attached to
these abstract entities in the schools of philosophy a,nd the
ology, and perhaps to a greater extent than was proper.
CHAPTER IX
OF THE IMPERFECTIONS OF WORDS
§ 1. Ph. We have already spoken of the double use of words.
The one is to register our own thoughts in order to aid our
memory which makes us talk to ourselves ; the other is to
communicate our thoughts to others by means of speech.
1 I have taken the liherty to coin the word as an equivalent of the French,
which I think is also coined by Leibnitz to express the abstraction of the
scholastics. — TR.
2B
370 LEIBNITZ'S CRITIQUE OF LOCKE [BK. m
These two uses show the perfection or imperfection of words.
§ 2. When we speak only to ourselves, it is a matter of indif
ference what words we employ, provided we remember their
meaning and do not change it. But § 3. the use of communication
is also of two kinds, civil and philosophic. The civil consists
in the conversation and use of the civil life. vThe philosophic
use is that made of words for the purpose of giving precise
notions and to express in general propositions certain truths.
Th. Very good: words are not less marks (notce) for us
(as the characters of arithmetic or algebra may be) than signs
for others ; and the use of words as of signs is as much* in
place when the question concerns the application of general
precepts to the usage of life, as when it concerns the discovery
or verification of these precepts. The first use of signs is civil,
and the second philosophic.
§ 5. Ph. Now it is difficult, chiefly in the following cases,
to learn and retain the idea which each word signifies, (1)
when these ideas are very complex; (2) when the ideas com
posing a new one have no natural bond between them, so that
there is in nature no fixed measure nor any model to rectify and
regulate them ; (3) when the model is not easy to be known ;
(4) when the meaning of the word and the real essence are
not exactly the same. The names of the modes are most lia
ble to be doubtful and imperfect for the two first reasons, and
those of substances for the two second. § 6. When the idea
of the modes is very complex, as that of the majority of the
terms of ethics, they rarely have precisely the same significa
tion iu the minds of two different persons. § 7. The" defect
also of the models renders these words equivocal. He who
first invented the word brusquer (to be abrupt with) understood
thereby what he found to the purpose, without informing those
who have used it as he of his precise meaning, and without
having shown them any constant model. § 8. Common use
regulates sufficiently the sense of words for ordinary conversa
tion, but it has no precision ; and the signification most con
formed to the peculiar nature of the language is every day
disputed. Many speak of glory, but few have the same under
standing of it. § 9. They are only simple sounds in the
mouths of many, or at least their meanings are very indefinite.
And in a discourse or conversation in which mention is made
en. ix] ON HUMAN UNDERSTANDING 371
of honor, faith, grace, religion, the church, and above all in dis
cussion, you will notice at once that men have different notions
which they apply to the same terms. And if it is difficult to
understand the meaning of the terms of the people of our
time, it is much more difficult to understand ancient books.
Fortunate is it that we may pass them by save when they
contain what we should believe and do.
Th. These remarks are good : but in regard to ancient books,
as we need to understand Holy Scripture above all, and as
Roman laws are still of great use in a good part of Europe, we
are indeed compelled to consult a great many other ancient
books ; the Rabbis, the Church Fathers, even the profane his
torians. Besides the ancient physicians also deserve to be
understood. The practice of medicine by the Greeks came
through the Arabs to us ; the water from the fountain has been
made turbid in the streams of the Arabs, and purified in many
respects since we have begun to have recourse to the original
Greeks. But these Arabs do not cease to be of use and we are as
sured that Ebenbitar,1 for example, who in his books on Simples
has copied Dioscorides, often serves to throw light upon him. I
find also that, next to religion and history, it is chiefly in medi
cine, as far as it is empirical, that the tradition of the ancients
preserved in writing, and in general the observations of another
1 Ibn-al-Baitar, e. 1197-1248, a distinguished Arabian botanist, — according
to Pouchet the most learned that the Arabian School has produced, — who
wrote a general history of simples, or of plants alphabetically arranged, a
mater ia medica, based upon and said to contain for the most part the work of
the Greek physician Dioscorides, c. 100 A.D., iiepi 'YArj? 'larpiK^, as well as a
variety of facts from other sources, including descriptions of plants not men
tioned by either Dioscorides or Pliny the Elder, 23-79. Most of iJaitar's
works still remain in MSS. in the libraries of Paris and the Escurial. Fr. R.
Diet/ published a small fragment of the work on Simples in his Aiwla-ta me
dica c.f, libris -/1//-VS., Lipsise, 1833, 8vo. There are also Grosse Zttsammcnstel-
lioif/ ii. d. Krilfte d. bekaunt. cinfaclien Heil-und-Nahrunysmittel v. . . . Ebn
JJ<i/t/iar. Aus d. Arabisc?ien ubersetzt r>. Dr. Joseph r. ftontfieimer, 2 vols.,
Stuttgart, 1840-42, and Traite des simples, trans, by L. Leclerc, in Inst. de
France, Notices et extraits des MSS. de la Bibl. Nationals, vol. 23, Pt. I., Paris,
1877, 4to. For some account of Baitar, rf. Leclerc in Gazette hebdom. de medi
cine et de chirurgie,xx.i\., 97, 129, Paris, 1875; F. A. Pouchet, Histoire des sciences
naturelles au moj/en dye, Paris, 1853, 8vo. Schaarschmidt says that Leibnitz
may have been led to the remark which lie here makes upon Baitar by the
Exercitationes de homonymis Jif/les iatrif-fe, appended to Claud. Salmasius,
ir.88-l<i53, PlintansB ej-ercitotioncs, P. 104. a. B. 110. a. A., Trajecti-ad-Rhenum,
1689, 2 vols., fol., where different accounts of Dioscorides are amended from
Ebnbitar. — TR.
372 LEIBNITZ'S CRITIQUE OF LOCKE [BK. m
may be of service. I have therefore always held in high
esteem physicians much versed in the knowledge of antiquity ;
and I was very sorry that Reinesius,1 excellent in both depart
ments (of knowledge), had turned aside to explain the rites
and history of the ancients, rather than to recover a part of
the knowledge they had of nature, in which it has been shown
that he would have been able furthermore marvellously to suc
ceed. When the Latins, Greeks, Hebrews and Arabs shall
some day be exhausted, the Chinese, supplied also with ancient
books, will enter the lists and furnish matter for the curiosity
of our critics. Not to speak of some old books of the Persians,
Armenians, Copts and Brahmins, which will be unearthed in
time so as not to neglect any light antiquity may give on doc
trines by tradition and on, facts by history. "And if there were
no longer an ancient book to examine, languages would take
the place of books and they are the most ancient monuments
of mankind. In time all the languages of the world will be
recorded and placed in the dictionaries and grammars, and
compared together ; this will be of very great use both for the
knowledge of things, since names often correspond to their
properties (as is seen by the names of plants among different
peoples), and for the knowledge of our mind and the wonder
ful variety of its operations. Not to speak of the origin of
nations, which is known by means of solid etymologies which
the comparison of languages will best furnish. But of this I
have already spoken. And all this shows the use and extent
of criticism, little considered by some otherwise very clever
philosophers who take the liberty to speak with contempt of
Rabbinarje- and in general of philology. We see also that
critics will find for a long time yet matter for fruitful exercise,
1 Thomas Eeinesius, 1587-1067, a physician who wrote on natural history
and medicine, and afterwards devoted himself to philological and antiquarian
studies. Among his works were, Scholct jnreconsultorum medica relrttionum
libris aliquot comprehensa, quibirs principia medlcirise in jus transmuta ex
professo examinatitnr, Lipsire, I»i79, 12-mo; Si/ntazma inscriptionem antiquarian
cum primis Romte veteris, quant m omissa est rccenw'o in Gruteii ope re., aim
comment, Lipsire, 1(582, fol. Cf. B. Schuchardt, Lebensbeschreibwif/en be-
ruhrn ter AZrzte und Naturforscher, welche aim Thiirin.r/en stammen. ' Corre-
spondenz-Bldtter des dHyemeinen arztlichen Vereinsvon Thurinqen Weimar
1888, xvii., 55(5, 601. — TR.
2 A term of disparagement, meaning the study made of the hooks of the
rabbis. — TR.
CH. ix] ON HUMAN UNDERSTANDING 373
and they will do well not to amuse themselves too much with
minutiae, since they have so many objects more pleasing for
treatment ; though I well know that minutiae also are often very
necessary with the critics for the discovery of more important
knowledge. And as criticism turns in large measure upon the
meaning of words and the interpretation of authors, especially
the ancients, this discussion about words joined with the men
tion you made of the ancients, makes me touch upon this
important point. But to return to your four defects of nomi
nation, I tell you, sir, that we can remedy them all, especially
since writing has been invented and they subsist only through
our negligence. For it depends upon us to fix their meanings,
at least in any scholarly language, and to agree to destroy this
tower of Babel. But there are two defects where the remedy
is more difficult, consisting the one in the doubt which exists
whether the ideas are compatible, when experience does not
furnish them all combined in one and the same subject ; the
other in the necessity for making provisional definitions of
sensible things, when our experience with them is insufficient
for more complete definitions : but I have spoken more than
once of both these defects.1
Ph. [I am going to tell you some things which will serve
further to clear up to some extent the defects you have just
remarked, and the third of those which I have indicated
makes it seem that these definitions are provisional ; viz. : —
when we have no sufficient knowledge of our sensible models,
i.e. the substantial beings of corporeal nature. This defect
also makes us ignorant as to whether we may combine the
sensible qualities which nature has not combined, because at
bottom we do not understand them.] Now if the signification
of the words which serve for the mixed modes is uncertain,
for lack of models which show the same composition, that of
the names of the substantial beings is uncertain for a wholly
contrary reason, because they must signify what is supposed to
be conformed to the reality of things, and to be related to the
models formed by nature.
Th. I have already more than once remarked in our pre
vious conversations that this is not essential to the ideas of
1 Cf. New Essays, Bk. III., chap. 6.— TR.
374 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
substances ; but I admit that ideas made after nature are the
surest and most useful.
§ 12. Ph. When then we follow the models wholly made
by nature, unless the imagination finds it necessary to retain
their representations, the names of substances have in ordi
nary use a double relation, as I have already shown. The
first is that they signify the internal and real constitution of
things, but this model cannot be known and consequently can
not serve to regulate the significations.
Th. That is not the question here, since we are speaking of
ideas of which we have models ; the internal essence is in the
thing, but we agree that it cannot serve as a pattern.
§ 13. Ph. The second relation is then that which the names
of substances immediately have to the simple ideas, which
exist at the same time in the substance. But as the number
of these ideas united in one and the same subject is great, men
speak of this same subject, forming very different ideas of it,
both by the different combination of the simple ideas they
make and because the greater part of the qualities of bodies
are the powers which they have of producing changes in
other bodies and receiving them ; witness the changes one of
the basest metals is capable of undergoing through the opera
tion of fire, and it receives many more yet at the hands, of a
chemist, through the application of other bodies. Further, one
is contented with weight and color as criteria for a knowledge
of gold; another includes ductility, fixedness; and the third
desires to make us take into consideration its solubility in
aqua regia. § 14. As things likewise often resemble each
other, it is sometimes difficult to designate their precise
differences.
Th. As bodies are really liable to be altered, disguised,
falsified, counterfeited, it is a great point to be able to dis
tinguish and recognize them. Gold is disguised in solution,
but it may be drawn off, either by precipitating it or dis
tilling the water ; and counterfeit or adulterated gold is
recognized or purified by the art of the assayers, which not
being known to everybody, it is not strange that men do not
all have the same idea of gold. And ordinarily it is only
the experts who have sufficiently just ideas of these mat
ters.
ix] ON HUMAN UNDERSTANDING 375
§ 15. Ph. This variety does not, however, cause so much
confusion in civil intercourse as in philosophic researches.
Tli. It would be more tolerable if it had no influence in prac
tical life where it is often important not to receive a Qui pro
quo, and consequently to know the characteristics of things or
to have at hand the class who know them. And it is especially
important as regards drugs and materials which are costly, and
of which you may have need on important occasions. The
philosophical confusion will manifest itself rather in the use
of more general terms.
§ 18. Ph. The names of simple ideas are less liable to equivo
cation, and we are rarely mistaken as regards the terms white,
bitter, etc.
Th. It is, however, true that these terms are not wholly
exempt from uncertainty ; and I have already noticed the
example of neighboring colors which are within the confines of
two species and whose species is doubtful.
§ 19. Ph. After the names of simple ideas, those of the simple
modes are least doubtful, as for example, those of figures and
numbers. But, § 20. the mixed modes and substances cause all
the trouble. § 21. Men will say that instead of imputing
these imperfections to the words, we should rather put them
to the account of our understanding ; but I reply that words
interpose themselves to such an extent between our mind and
the truth of things, that we may compare them with the
medium, across which pass the rays from visible objects, and
which often spreads a mist before our eyes ; and I have tried
to think that, if the imperfections of language were more
thoroughly examined, the majority of the disputes would cease
of themselves, and the way to knowledge and perhaps to peace
would be more open to men.
Th. I think we could succeed from this time in written dis
cussions, if men would agree upon certain rules and execute
them with care. But in order to proceed exactly viva voce and
at once, some change in the language would be necessary. I
have elsewhere T entered upon this enquiry.
1 In Iris writings in furtherance of hi a plan for the establishment of a General
Characteristic or Philosophical Language, Spdcieuse f/enerale, a project which
Leibnitz had very much at hp-irt, as appears from his frequent allusion to the
subject, and upon wlnoli throughout his entire life he spent much labor, chiefly
376 LEIBNITZ'S CRITIQUE OF LOCKE [BK. m
§ 22. Ph. While waiting for this reform which will not be
ready very soon, this uncertainty regarding words should teach
us to be moderate, especially when it is a question of imposing
upon others the sense attributed by us to the ancient authors,
since in the Greek authors it is found that nearly every one
speaks a different language.
Th. I have been rather surprised to see that Greek authors
so distant from one another in time and place, as Homer,
Herodotus, Strabo, Plutarch, Lucian, Eusebius, Procopius,
Photius, approach so closely, while the Latins have changed
so much, and the Germans, English, and French much more.
But the fact is, the Greeks since Homer's time, and still
more when Athens was in a nourishing condition, had good
authors which posterity has taken as models, at least in writ
ing. For no doubt the common language of the Greeks must
have been much changed already under the rule of the Romans.
And this same reason accounts for the fact that the Italian
has not suffered so great a change as the French, because the
Italians, having had earlier writers of durable reputation, imi
tated and moreover esteemed Dante, Petrarch, Boccaccio, and
other authors at a time when those of the French were no
longer appreciated.
CHAPTER X
OF THE ABUSE OF WORDS
§ 1. Ph. Besides the natural imperfections of language,
there are some that are voluntary and arise from negligence, and
it is an abase of words to use them so badly. The first and most
palpable abuse is, § 2. that we attach no clear idea to them. Of
these words there are two classes : the first have never had
any definite idea, either in their origin or ordinary use. For
the most part philosophical and religious sects have introduced
preparatory, and with little positive results in accomplishing his plan. Cf.
New Essays, Bk. IV. chap. (J, § 2, Th., chap. 17, § 13, Th.; Gerhardt, Leibniz,
philos. Schrift., 3, 216; 4, 27 sq., Krdmaun, 6 sq.; G. 7, 3 sq., E. 82 sq., <>(>9 sq.;
Trendelenburg, Ucber Leibniz. Entwurf einer allyemeinen Character istik, in
his Hislor. Beitraf/c z. Philos., vol. 3, pp. 1 sq., Berlin, 1807; L. Xeff, G. W.
Leibniz als Sprachforscher und Etymologe, Ft. II., pp. 13 sq., Heidelberg,
1870-1.— TR.
en. x] ON HUMAN UNDERSTANDING 377
them in order to support some strange opinion, or to conceal
some weak place in their system. They are, however, distin
Crushing characters in the mouth of members of the party.
§ 3. There are other words, which in their first and common
use have some clear idea, but which have since been appro
priated to very important matters without attaching to them
any certain idea. In this way the words wisdom, glory, grace,
are often in the mouths of men.
Th. I believe that insignificant words are less in number
than you think, and that with a little care and good will you
can fill up their void or fix their indefiniteness. Wisdom
appears to be nothing else than the science of happiness.
Grace is a favor done to those who do not deserve it and who
find themselves in a state where they need it. And glory is
the fame of the excellence of some one.
§ 4. Ph. I do not wish now to examine whether there is
anything to be said in regard to these definitions, but rather to
notice the causes of the abuse of words. In the first place, we
learn the words before we learn the ideas belonging to them, and
children accustomed thereto from the cradle use them in like
manner during their whole life : the more as they do not cease
to make themselves understood in conversation, without ever
having fixed their idea, by using different expressions in order
to make others understand their meaning. This, however, often
fills their discourses with a quantity of vain sounds, especially
in matters concerning morals. Men take the words they find
in use among their neighbors, and in order not to appear
ignorant of their meaning employ them confidently without
giving them a certain sense : and, as in this kind of discourse
they are rarely in the right, they are also rarely convinced
that they are wrong; and to wish to draw them from their
error is to wish to dispossess a vagabond.
Th. Men in fact take so rarely the necessary trouble to
understand terms or words that I have more than once been
astonished that children can learn languages so soon, and that
men furthermore speak them so accurately ; a view to which
we attach so little in instructing children in their mother
tongue and which others think of so little in acquiring clear
definitions ; the more so as those we learn in the schools do
not ordinarily concern the words in public use. For the rest, I
378 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
admit that men frequently happen to be wrong when indeed
they discuss seriously and speak in accord with their feeling ;
but I have also remarked often enough that in their speculative
discussions upon matters within the province of their mind,
they have every reason for two sides, except in the oppositions
they make to each other where they misconstrue another's
view. This arises from the bad use of terms and sometimes
also from a spirit of contradiction and affectation of superi
ority.
§ 5. Ph. In the second place the use of words is sometimes
inconstant, a practice only too general among scholars. It is
nevertheless a plain cheat, and if voluntary, is folly or malice.
If any one so conducted himself in his accounts (as to take an
X for a V), who, I pray, would have anything to do with
him ?
Th. This abuse being so common not only among scholars
but also in the world at large, I believe that it is due rather to
bad custom and inadvertence than to malice. Usually the
different significations of the same word have some affinity ;
this makes one pass for another and does not give time to con
sider what is said with all the precision that is desirable. We
are accustomed to tropes and figures, and some elegance or
brilliant falsehood easily imposes upon us. For we oi'tener
seek pleasure, amusement, and appearance, than truth ; besides,
vanity mixes itself therein.
§ 6. Ph. The third abuse is an affected obscurity, either by
giving terms in use unusual meanings, or by introducing new •
terms without explaining them. The ancient Sophists, whom
Lucian ridicules so properly, pretending to speak of every
thing, covered their ignorance under the veil of the obscurity
of words. Among the sects of philosophers the Peripatetic
has shown itself remarkable by this defect; but the other
sects, even among the moderns, are not wholly exempt from it.
For example, the people who abuse the term extension, and
find it necessary to confuse it with that of body. § 7. Logic
or the art of discussion, which is held in such high esteem,
has helped to maintain this obscurity. § 8. Those who
have given themselves up to it have been useless or rather
detrimental to the state ; § 9. while mechanics, though de
spised by the learned, have been serviceable to human life.
CH. x] ON HUMAN UNDERSTANDING 379
But these obscure doctors have been admired by the ignorant ;
and they have been thought invincible because provided with
briers and thorns, into which it was no pleasure to thrust one's
self, their obscurity alone serving as a defence of their absurd
ity. § 12. The evil is that this art of obscuring words has
confused the great rules of men's action, religion and justice.
Th. Your complaint is largely just : it is nevertheless true
that there are, though rarely, pardonable and even praiseworthy
obscurities, as when we profess to be enigmatical, and the
enigma is timely. Pythagoras1 so used it, and it is frequently
the manner of the Orientals. The alchemists, who are called
adepts, declare that they wish to be understood only by the
sons of the art. And that would be well, if these pretended
sons of the art had the key to the cipher. A certain obscurity
may be allowed; but something must be concealed which is
worth divining, and the enigma must be decipherable. But
religion and justice demand clear ideas. It seems that the
little order brought into their teaching has made the confusion
in their doctrine ; and the indeterminateness of the terms is
perhaps more harmful than their obscurity. Now as logic is
the art which teaches the order and connection of thoughts, I
do not see any reason for blaming it. On the contrary it is for
want of logic that men deceive themselves.2
§ 14. Ph. The fourth abuse is when we take words for things,
i.e. believe that the terms correspond to the real essence of the
1 Pythagoras, c. 580-570-c. 500 B.C. The reference is to his so-called Symbols,
or sayings preserved in a symbolic form, in order that their meaning might be
concealed from the uninitiated, and the characteristic of which is the union of
an ethical prescript with an external action relatively indifferent. Cf. Dioge
nes Laertius, De vitis, doc/matibus, et apophtheymatis clarorumphilosophorum,
VIII, 17 sq. , who gives some of these symbols with interpretations of a part of
them ; Zeller, Philos. d. Griec., 5th ed., 1892, Vol. 1, p. 324, note 2, 462. Mullacli,
Fraymt. Philos. Grsec., Vol. 1, p. 504 sq., gives a collection of these sayings.
Examples are: "Carry not the image of God in the finger-ring," "Stir not
the fire with the sword," " Sacrifice and pray with bare feet." Guttling,
Gesammlt. Abhandl., Vol. 1, p. 278 sq., 2, 280 sq., has given them a "pene
trating investigation," on which see the note of Zeller above cited. Leibnitz
on Pythagoras, cf. Gerhardt, Leibniz, philos. Schrift., 7, 147. — TR.
2 Leibnitz, while rejecting the over-refinements of the scholastic logic, never
theless rightly values formal logic as an aid to clear thinking and correct
reasoning. Cf. the letter to Gabriel Wagner, 1696, Gerhardt, Leibniz, philos.
Schrift., 7, 512 sq., Erdmann, 418 sq., Guhrauer, Leibniz, deutsche Schrift., 1,
374 sq., Berlin, 1838. —TR.
380 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
substances. Who is there brought up in the Peripatetic phi
losophy who does not think that the ten names which represent
the predicaments are exactly conformed to the nature of things;
that the substantial forms, vegetative souls, abhorrence of a vacuum,
intentional species, etc., are something real ? The Platonists
have their soul of the world, and the Epicureans the tendency of
their atoms towards movement at the time when they are at
rest. If the aerial or ethereal vehicles l of Dr. More had pre
vailed in. any corner of the world they would have been thought
no less real.
Tli. Properly speaking this is not to take words for things,
but to believe that true which is not so, an error too common
with all men, depending not alone upon the abuse of words,
but consisting in something . entirely different. The design
of the predicaments is a very useful one, and we ought to
think of rectifying rather than of rejecting them. Substances,
quantities, qualities, actions or passions, and relations, i.e. five
general names of things may, together with those formed by
their composition, suffice, and have not you yourself, in mar
shalling ideas, been willing to grant them as the predicaments ?
I have spoken above of substantial forms.2 And I know not
whether we have sufficient reason for rejecting the vegetative
souls,3 since persons of much experience and judgment reeog-
1 The aerial or ethereal vehicles are the aerial or celestial bodies of the
spirits, which, according to More, the souls of men after sufficient purification
attain, either at death, in the case of a very few of the noblest and most
heroic, or at some period after death. Cf. H. More, Opera omnia, Londini,
1679, 2 vols., fol. ; Tract, de immortalitate animse, Bk. III. chap. 1, Axioma, 27,
§§ 3, 28 sq., Vol. 2, p. 396 sq., chap. 11, § 2, p. 427; Antidotus adversus Atheis-
mum, Bk. III. chap. 3, § 9, Vol. 2, p. 99. — TR.
'2 Cf. ante, p. 349 and note. — TR.
3 The scholastic philosophy recognized three forms or kinds of souls, corre
sponding to the three orders of life, plants, animals, and men, viz.: the vege
tative, sensitive, and intellective (anima vegetabilis or nutritiva, sensibilis or
sensitiva, intellectica or rationalis). Of these the vegetative is the lowest,
the sensitive the next higher, the intellective the highest; and the higher
form includes potentially in itself the lower and subordinate form and its
functions. The functions of the vegetative soul are nutrition, growth, repro
duction ; of the sensitive soul, sensation, feeling, perceptional, appetitive and
emotional activity ; of the intellective, those of the reason and the will. In
man, these several functions are all united in the intellective or rational soul,
which he alone possesses, and which comprises within itself the sensitive and
vegetative souls. Cf. Stockl, Gesch. d. Philos. d. Mittelalters, II. 2 [Vol. 3],
592 sq., 618 sq., 633 sq. — TR.
CH. x] ON HUMAN UNDERSTANDING 381
nize a great analogy between plants and animals, and you, sir,
have appeared to admit animal souls. Abhorrence of a vacuum
may be soundly understood; i.e. supposing nature has once
filled space, and that bodies are impenetrable and non-condens
able^ she could not admit any vacuum ; and I consider these
three suppositions well grounded. But the intentional species,1
which are to make the connection between the soul and the
body, are not so, though we may excuse the sensible species,1
1 Cf. 5th letter of Leibnitz to Clarke, § 84, Gerhardt, 7, 410, Erdmann, 773,
b, Jacques, 2, 465, Dutens, 2, Pt. I, 161, trans. Duncan, 275.
The doctrine of the intentional species (species inlentionales] to which
were opposed the real species (species reales) or the actual forms of things,
arose in the attempts of the Mediaeval Schoolmen to explain the process and
philosophy of sense-perception and cognition. Two views have in general been
held concerning their nature: 1. That they were the forms, similitudes, or
images (formse, similitudines, simulacra} of external objects, different both
from the mind and from .these objects, the intermediate and vicarious repre
sentatives of these objects in perception and thought, the media through
which the mind infers and comes to know these external objects — a form of
the doctrine of mediate perception. 2. That they were modifications of the
mind itself, occasioned by the action upon the mind of the external object and
the mind's responsive reaction thereto, by which the mind is likened or con
formed to the given object and so determined immediately to cognize it.
The latter view is maintained by the Roman Catholic psychologists, as being
the doctrine of the greatest of the schoolmen, such as Albertus Magnus,
Thomas Aquinas, Duns Scotus, and as giving the real meaning of the terms
they use. It is the more correct interpretation.
The intentional species, according as they affected or were modifications of
the sense or the intellect, were divided into sensible species (species sensibiles)
and inii-Uiijiblc <>r intellectual species (species intelliijibiles eel intellect tiales).
Both the wiisible and the intelligible species were further distinguished as
impri'sxed- species (species impressa) and expressed species (species expressa).
According to the representative theory of the intentional species, the species
iiiiltrcxsa was the vicarious existence emitted by the object, impressed on the
particular faculty, and concurring with it in its operation; while the species
rsi>rt'xxa was the actual operation elicited by the faculty and the impressed
species conjointly, i.e. the sensations and intellections. The direct or imme
diate theory regarded the genesis of species, whether as sensible or intelligible,
as exhibiting two stages : 1. In sensuous cognition, (a) the species sensibilis
iinprcssa, or '' the modification of the sensuous faculty viewed as an impres
sion wrought in the mind by the action of the object," and (b) the species
sensibilis e.i'i>ressa, or " the reaction of the mind as an act of cognitive con
sciousness." 2. In intellectual cognition, (a) the species intelli'/ibilis im-
press((, or the "modification effected in the recipient capacity" of the
intellectus patiens vel possibilis (the passive intellect — Aristotle's you? n-a^rjn-
Ko?),and (b) the specie* intellit/ibHIs r//>/v.s.sv/, or the "mental modification
reflecting the essence of the object, and by means of which the object is ap
prehended," a modification due to the act of the intellectus agens (the active
intellect — Aristotle's yoCs Trotr/rt/co?).
382 LEIBNITZ'S CRITIQUE OF LOCKE [UK. m
which proceed from the object to the distant organ, meaning
thereby the propagation of motion. I admit that there is no
Platonic soul of the world, for God is beyond the world, extra-
mundana intelligentia, or rather supramundana.1 I know not
whether by the tendency to movement of the Epicurean atoms
you understand the weight attributed to them, no doubt with
reason, since they maintain that bodies all move of them
selves in one and the same direction. The late Henry More, a
theologian of the English Church, wholly clever as he was,
showed himself a little too ready to invent hypotheses which
were neither intelligible nor apparent; witness his Hylarcliic
principle2 of matter, a cause of weight, elasticity, and other
wonders which are met with. I have nothing to say of these
ethereal vehicles, having never examined their nature.
§ 15. Ph. An example touching the word matter will assist
you the better to enter into my thought. Matter is taken as
The doctrine of the intentional species was held by the Realists, Aquinas,
Duns Scotus, and others. The Nominalists, especially Durandus, Biel, and
Occam, rejected it, and the doctrine was exploded in the seventeenth century,
largely by the arguments of Gassendi, Hobbes, and Descartes. On the whole
subject, r/'. Hamilton's field, 8th ed., Edinburgh, 1880, Vol. 1, p. 2(57 sq., and
Note M., Vol. 2, p. 951 sq.; Lects. on Metaphys., Boston, 1875, p. 291 sq., and
notes; Stockl, Gesch. d. Philos. d. Mittelalters, II. 1 [Vol. 2] 403 sq., II. 2
[Vol. 3] S08, 905, 978, 991 .NY/., III. [Vol. 4] 634 sq.; Haureau, Histoire de la
pJiilox. xfolaatique, II. 1 [Vol. 2] 417 sq., II. 2 [Vol. 3] 247 sq., 378 sq. ; Prantl,
GcscJt. d. Logik ini Abendlandc, Vol. 3, pp. 113, 210 sq., 294, 335 sq. ; Maher,
S. J., Psychology (Manuals of Catholic Philosophy — Stonyhurst Series), pp.
49-53, 290-297, London: Longmans, Green & Co., 1890 ; Zigliara, tiitmnw
Phitoxnjjhica, 3d ed., Lugduni, 1880, Vol. 2, pp. 243-4, 200 sq.; Suarez, l)c
Ani/na, Lib. III. cc. 2, 3; Kleutgen, Philos. d. Vorzeit, §§ 18-52; Sanseverino,
].)jtn<tnii.lo(/ia, Neapoli, 18G2-(i(!, Vol. 1, pp. 373-403 (of which pp. 390-400
contain "an effective refutation of the charge of representationism against
St. Thomas and ihe leading scholastics, based on the doctrine of species"),
Vol. 2. pp. 580 fif{. — TK.
: Cf. Theodice<-, Pt. II. § 217, Gerhardt, 0, 248, Erdmann, 571, a, Jacques, 2,
2 )5. - TR.
- ('/. Gerhardt, Leibniz, philos. Schrift., 7,339: letter to Placcius, Sept. 8,
lf!«K), Dutens, Lcibnit. op. om., (5, 48; to T. Burnett, Aug. 24 (v.s.) 1(597, G. 3.'
217, D. (!, 2(53. More rejected the mechanical explanation of physical natuiv,
and adopted the principium hylarchici.nn, or spiritim nuturse, as he designates
it, the immaterial force in all nature, the principle of tlu- movement and
sympathy of beings, similar to the aii/ma nunirfiot the Platonists and the
archfBiis (cf. ante, p. 07, note 3) of the Alchemists. Of. H. More, Op<>r« ontnia,
Londini, 1079, Enchiridion metaphy*., especially in the Scholia, to chap. 13,
§ 4, Vol. 1, p. 222 xq. ; also Tract, de immortalitate unimse, Bk. III. chap 12,
Vol. 2, p. 430. — TR.
CH. x] ON HUMAN UNDERSTANDING 383
an entity really existing in nature, distinct from the body;
which indeed is thoroughly self-evident ; otherwise these two
ideas might be put indifferently the one in the place of the
other. For we may say that one single matter composes all
bodies, but not that a single body composes all matter.
Neither will we say, I think, that one matter is greater than
another. Matter expresses the substance and solidity of
body ; thus we no more conceive different matters than differ
ent solidities. But since matter has been taken as a name of
something existing under this determination, this thought has
produced unintelligible discourse and confused discussion upon
mater ia prima.
Th. This example appears to me to serve rather to excuse
than to blame the Peripatetic philosophy. If all silver were
figured, or rather because all silver is figured by nature or art,
is it less allowable to say that silver is an entity really existing
in nature, distinct (taking it in its precision) from the plate or
the money ? You will not on that account say that silver is
nothing else than certain qualities of money. Thus it is not
so useless as you suppose to reason in general physics about
materia prima and to determine its nature in order to know
whether it is always uniform, whether it has some other
property besides impenetrability (as I in fact have shown l
after Kepler that it also has what may be called inertia), etc.,
although it is never found wholly pure ; as it would be allow
able to reason about pure silver, although we had none with us
nor the means of purifying it. I do not at all disapprove
what Aristotle has said about materia prima;2 but one cannot
1 Cf. De ipm nntura, 1008, § 11, Gerhardt, Leibniz, philos. Schrift., 4, 510,
Erdmann, 157, a, Jacques, 1, 4G2 (in French), Dutens, 2, Pt. II., 54, trans.
Duncan, 119; Theodicee, Pt. I., § 30, G. 0, 119, E. 512, a, J. 2, 89, Dutens, 1,
141 (in Latin); $i>ecii>te>/ di/namicum, 1(595, Pt. I., Gerhardt, Leibniz, r/xi.th.
Xfhrlft., (i, 234 ,SY/., Dutens, 3, 315 .sr/., .trans. Appendix, 670 sq. ; G. Leibniz.
p7iil»x. Schrift.. 4, 4(14-7, Dutens, 2, Pt. I., 234-7, two letters to the editor of the
"Journal des Savans." in the numbers for June 18th, K591, January, 1(>93, the
first originally a fragment from a letter to Antonio Alherti, G. 7. 447-9 : 5th
letter to Clarke, § 102, G. 7, 414, E. 775, h, J. 2, 470, Dutens, 2, 1(55, trans. Duncan,
2SO. In the letter to Jar. Thomasius, April 20-30, I(5(i9 (cf. G. 1, 17. 18, 24),
Leibnitz affirmed that matter consisted of extension and inpenetrability only.
-TR.
2 Cf. Zeller, Philos. d. Griech., 3d ed., 1879, II. 2 [Vol. 4] , p. .'520, note 2 ; and
Bonitz, L)d. .Arixt. xttb roc. CAT?, in vol. 5 of Berlin Academy, ed. of Aristotle.
Cf. also Gerhardt, Leibniz, philoa. Schrift., 7, 259. — TR.
384 LEIBNITZ'S CRITIQUE OF LOCKE [BK. m
help blaming those who have stopped too soon and have con
jured up chimeras out of the ill-understood words of this
philosopher, who perhaps also has given too much occasion
sometimes for this misconception and nonsense. But we
should not exaggerate so much the defects of this celebrated
author, because we know that many of his works were not
completed or published by himself.
§ 17. Ph. Thejifth abuse is the putting of words in the place
of things which they do not and cannot in any way signify.
It occurs when by the names of substances we mean to say
something more than this : what I call gold is malleable
(although at bottom then gold signifies nothing else than what
is malleable), intending to have it understood that mallea
bility depends upon the real essence of gold. Thus we say
that it is right to define man with Aristotle as a reasonable
animal ; and that it is not right to define him with Plato
as a two-legged animal without feathers and with broad nails.
§ 18. There is scarcely any one who does not suppose that
these words signify a thing having a real essence upon which
these properties depend; but it is a plain abuse when the
complex idea signified by this word does not include this thing.
Th. For myself I should rather think that we are plainly
wrong in censuring this common usage, since it is very true
that in the complex idea of gold is included the thought that
it is a thing having a real essence, whose constitution is un
known to us in detail otherwise than that upon it depend such
qualities as malleability. But in order to express its mallea
bility without identity and without the defect of coccyx-m or
repetition (see chap. 8, § 18), l we must recognize this thing by
other qualities, as color and weight. And it is as if we said
that a certain fusible body, yellow and very heavy, called gold,
has a nature which gives it besides the quality of being very
soft to the hammer and capable of being made very thin. As
for the definition of man attributed to Plato, which he appears
to have made only for practice, and which you would not, I
think, compare seriously with that which is received, it is
manifestly a little too external and provisional ; for if this
Cassowary, of which you recently spoke (chap. 6, § 34), had
1 The reference is incorrect. Perhaps chap. 6, § 18, is meant, or chap. 10,
§18.-TB.
en. x] ON HUMAN UNDERSTANDING 385
been found to have wide nails, it would be man ; for it would
not have been necessary to strip it of its feathers, as in the
case of the cock which Diogenes, as they say, wished to make
a Platonic man.1
§ 19. Ph. In the mixed modes, as soon as an idea entering
therein is changed, you at once recognize it as another thing,
as plainly appears in the words, murder, which signifies in
English (as Mordt in German), homicide premeditated with
design; manslaughter (a word corresponding in origin to homi
cide), a voluntary but not premeditated homicide; chance-
medley (a chance melee, according to the force of the word),
homicide committed without design; for what is expressed by
the names and what I think to be in the thing (which I called
before -nominal essence and real essence] is the same. But it is
not so in the names of substances; for if one puts into the idea
of gold what another leaves out, for example fixedness and
solubility in aqua regia, men do not think for that reason that
its species has been changed, but only that the one has a more
perfect idea than the other of what constitutes the real con
cealed essence to which the name of gold is given, although this
secret relation is useless and serves only to involve us in diffi
culties.
Tli. I think I have already made this statement ; but I am
going also to show you clearly here, that what you, sir, have
just said, is found in the modes, as in the substances, and that
we have no ground for censuring the internal essence for this
relation. Here is an example : we may define a parabola, in
the sense of the geometers, as a figure in which all the lines
parallel to a certain straight line are united by thought in a
certain point or focus. But it is rather the exterior and the
effect which is expressed by this idea or definition, than the
internal essence of this figure or what can at once make known
its on'gin. We may at the beginning even doubt if such a
figure as we wish and which ought to produce this effect is a
possible thing; and it is this which with me shows whether a
1 Of. Diogenes Laertius, c. 230-250, T)e ritit, dor/mat ibus et apophthegm at is
Clarorum phllOSOphoritm Ub. dccein, VI. 40: IIAartofo? opitra/aeVou/AyflpajTro? ecrri
£i)ov Si-vow, aTTTepov, (cat euSoKi/aoui'TOs, TiAa? [Ato-yerrj? 6 KViav] d\eKTpv6va eitrryi'ey/cei' eis
TTJI' cr^oArji/ aiirov, KO.I <f>rjcni', OUTO? ecrrii' 6 IIAarwi'o? avOpwnos. oOev TO> 6pa> Trpoaere^Tj
Tb n\aTvui>vxoi'. The definitions ascribed to Plato, and found in some editions
of his works, are beyond doubt spurious. — TR.
2 c
LEIBNITZ'S CRITIQUE OF LOCKE [UK. in
definition is only nominal and taken from the properties, or
whether it is also real. But he who mentions the parabola
and knows it only by the definition I have just spoken of,
ceases not, when speaking of it, to understand a figure which
has a certain construction and constitution unknown to him,
but which he wishes to learn in order to be able to draw it.
Another who has examined it more thoroughly will add some
other property, and will discover, for example, that in the
figure asked for, the portion of the axis intercepted between
the ordinate and the perpendicular drawn to the same point
of the curve is always constant, and equal to the distance
from the vertex to the focus. He will thus have a more per
fect idea than the former, and will come more easily to the
drawing of the figure, although he is not yet there. And,
moreover, we shall agree that it is the same figure, the consti
tution of which is still concealed. You see then, sir, that all
that you have found and partly censured in the use of words
signifying substances is also found and found plainly justified
in the words signifying the mixed modes. But what has made
you think that there was some difference between the sub
stances and the modes,1 is merely the fact that you have not
consulted here the intellectual modes difficult of discussion,
which are found to resemble in all this bodies which are still
more difficult to know.
§ 20. Ph. Thus I fear I must suppress what I wished
to say to you, sir, of the cause of what I have thought an
abuse, as if it were because we falsely think that nature
always acts with regularity and fixes limits to each species by
this specific essence or internal constitution which we there
understand and which always follows the same specific name.
Tli. You see clearly then, sir, by the example of the geo
metrical modes, that we are not wrong in referring them to
internal and specific essences, although there is great differ
ence between sensible things, whether substances, or modes,
of which we have only nominal provisional definitions, and
of which we do not readily hope for real ones, and between
the intellectual modes, difficult of discussion since we can at
last reach the internal constitution of the geometrical figures.
1 Jacques reads : " c'est que vous n'avez point consulte," etc. Gerhardt and
Erdmann read: " n'est que vous," etc. — TK.
x] ON HUMAN UNDERSTANDING
§ 21. Ph. [I see at last that I should have been wrong in
laying the blame of this relation upon the essences and internal
constitutions, under the pretext that this would render our
words signs of nothing or of an unknown something. For
what is unknown in certain respects may make itself known
in another way, and the inner nature may partly reveal itself
by the phenomena which spring from it. And as for the
question : whether a monstrous foetus is a man or not ? I see
that, if it cannot be decided at once, this fact does not prevent
the species from being well fixed in itself, our ignorance
nowise changing anything in the nature of things.]
Tli. In fact, some very clever geometers have chanced to
possess insufficient knowledge as to what the figures were,
many qualities of which seemingly exhaustive of the subject
they knew. For example, there were some lines called pearls,1
of which there were given indeed the quadratures and the
measure of their surfaces and of the solids made by their
revolution, before it was known that they were only a com
position of certain cubic paraboloids. Thus in considering
beforehand these pearls as a particular species, they had only
provisional knowledge of them. If this may happen in geom
etry, do you wonder that it is difficult to determine the species
of corporeal nature which are incomparably more complex ?
§ 22. Ph. Let us pass to the sixth abuse in order to con
tinue the enumeration begun, although I see clearly that some
of the points must be struck from the list. This general but
little noticed abuse is this : men having by long use attached
certain ideas to certain words, imagine that this connection is
manifest and that everybody agrees to it. Whence it comes
that they feel very strange, when asked the meaning of the
words they employ, when indeed the question is an absolutely
necessary one. There are few people who do not take it as an
1 Cf. New Essays, Bk. IV., chap. 7, § 4, Th. infra, p. 465. Rene Franyois
Walter de Sluse, 1622-1685, a Flemish geometer, canon of Liege cathedral, and
author of the method for the construction of the roots of equations of the 3d
and 4th degree, "which consists in reducing the resolution of the proposed
equation to that of the system of two equations representing two conies, by
introducing an unknown auxiliary whose elimination reproduces the primitive
equation." He developed this method in his Mesolabium ct i>roblemat<i solida,
etc., 4to, Leodii Eburonum, 1<><>8. Leibnitz mentions this work in a letter to
Hobbes, 13-22 July, 1070, Gerhardt, Leibniz, philots. Schrift., 7, 573. — TR.
388 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
affront if asked what they mean when speaking of life. But
the vague idea they may have of it is insufficient when the
question arises as to the knowledge whether a plant, already
formed in the seed, or a pullet in the egg not yet in process
of incubation, or a man in a swoon without sense or motion,
has life. And although men do not wish to appear so little
intelligent or so obtrusive as to find it necessary to ask for an
explanation of the terms used, nor critics so disagreeable as to
censure others unceasingly for the use they make of words,
nevertheless when it is a question of exact research, such
explication is necessary. Often scholars of different parties
in the reasonings they display the one against the other
merely speak different languages and think the same tiling,
although perhaps their interests are different.
Tli. I think I have explained sufficiently my views upon
the notion of life, which must always be accompanied by per
ception in the soul; otherwise it would be only an appearance,
as the life which the American savages attributed to watches
or clocks, or which those magistrates attributed to the mario
nettes, who believed them animated by demons, when they
desired to punish as a sorcerer the one who had first pre
sented this spectacle in their city.
§ 23. Ph. In conclusion, words serve (1) to make our
thoughts understood, (2) to do this easily, and (3) to furnish
entrance into the knowledge of things. Words fail at the
first point, when they have no definite and constant idea
either received or understood by others. § 23. They fail in
facility, when they have very complex ideas, without distinct
names ; this is often the fault of the languages themselves
which have no names ; often also of the man who is ignorant
of them ; in that case extensive paraphrases are necessary.
§ 24. But when the ideas signified by the wrords do not agree
with what is real, they fail in the third point. § 26. (I) He
who has terms without ideas is like a man who has only a
catalogue of books. § 27. (2) He who has very complex ideas
is like a man who has a quantity of books in loose sheets
without titles, and who could not give the book save by giving
the sheets in succession. § 28. (3) He who is not constant
in the use of signs is like a merchant who sells different goods
under the same name. § 29. (4) He wrho attaches particular
CH. x] ON HUMAN UNDERSTANDING 389
ideas to received words cannot enlighten others by the light he
may have. § 30. (5) He who has in his head ideas of sub
stances which never had existence, cannot advance in real
knowledge. § 33. The first will speak in vain of the taran
tula or of charity. The second will see new animals without
being able easily to show them to others. The third will
take body sometimes as a solid, sometimes as a mere exten
sion ; and by frugality he will designate sometimes the virtue,
sometimes the kindred vice. The fourth will call a mule
by the name horse, and what everybody calls prodigal will be
to him generous ; and the fifth will seek in Tartary on the
authority of Herodotus 1 a nation composed of men having only
one eye. I remark that the first four defects are common to
the names of substances and modes, but that the last is pecu
liar to substances.
Th. Your remarks are very instructive. I will only add
that you seem to have something chimerical still in your ideas
of the accidents or forms of being ; and so the fifth defect is
also common to substances and to accidents. The extravagant
shepherd was not so, only because he believed there were
nymphs concealed in the trees, but also because he always
expected romantic adventures.
§ 34. Ph. I had thought to conclude, but I remember the
seventh and last abuse., which is that of figurative terms or
allusions. But there will be difficulty in thinking it an abuse,
because what is called wit and imagination is better received
than truth wholly dry. It goes well in discourse where you
only seek to please; but at bottom, order and clearness ex-
cepted, all the art of rhetoric, all these artificial and figura
tive applications of words, serve only to insinuate false ideas,
to excite the passions and seduce the judgment, so that they
are nothing but pure frauds. Nevertheless this fallacious art
is given the first rank and rewards. It is evident that men
care but little for truth and much prefer to deceive and to be
deceived. This is so true that I doubt not that what I have
just said against this art is regarded as the result of an extreme
audacity. For eloquence, like the fair sex, has charms too
powerful to allow itself to be opposed.
1 Book III., chap. 116 : IV., chaps. 13, 27 : <\f. also yEschylus, Prometheus, 823
(804, Dindorf), 3d ed., F. A. Paley, London, 1870; Pausanius, 1, 24, 6. — TR.
390 LEIBNITZ'S CRITIQUE OF LOCKE [BK. in
Th. Very far from censuring your zeal for the truth, I
find it just. And would that it might be effective. I do
not wholly despair of it, because you seem to me, sir, to combat
eloquence with its own weapons, and to have an eloquence of
another species superior to this deceptive kind, as there was a
Venus Urania, mother of divine love, before whom this other
bastard Venus, mother of a blind love, dared not appear with
her child with eyes blinded.1 But that indeed proves that
your thesis needs some moderation, and that certain adorn
ments of eloquence are like the Egyptian vases which you
could use in the worship of the true God. It is as in painting
and music, which are abused, one of which often represents
grotesque and even hurtful imaginations, and the other softens
the heart, and the two amuse. in vain ; but they can be usefully
employed, the one to render the truth clear, the other to make
it effective, and this last result must be also that of poetry
which contains rhetoric and music.
CHAPTER XI
OF THE REMEDIES WHICH MAY BE APPLIED TO THE IMPER
FECTIONS AND ABUSES JUST SPOKEN OF
§ 1. Ph. This is not the place to plunge into this discussion
upon the use of a true eloquence, and still less to reply to your
obliging compliment, since we ought to think of bringing this
matter of u'ords to an end, by seeking the remedies for the
imperfections we have noticed therein. § 2. It would be ridic
ulous to attempt to reform the languages, and to desire to com
pel men to speak only according to the measure of their knowl
edge. § 3. But it is not too much to desire that philosophers
speak exactly, when the question concerns a serious search for
the truth : without this all will be full of error, opiniativeness,
and vain disputes. § 8. The first remedy is to use no word
1 For the myth here referred to 1>y Leibnitz, cf. Plato, Symposium, 180, D,
Jowett's trans. Vol. 2, p. 32, 2d ed., 1875, Vol. 1, p. 550, 3d ed., 1892: Pausa-
nias, 9, 16. 3: also Harrison- Verrall, Mythology and Monuments of Ancient
Athene, 212 »q., London, Macmillan & Co., 1890; Preller, Griech. MythoL, 2d
ed., 1860, Vol. 1, p. 265. — TR.
en. xi] UN HUMAN UNDERSTANDING 391
without attaching thereto an idea, instead of frequently em
ploying words like instinct, sympathy, antipathy, without
attaching any sense to them.
Th. T.he rule is good ; but I know not whether the examples
are pertinent. Everybody seems to understand by instinct an
inclination of an animal to what is proper for it, without on
that account apprehending its reason ; and men indeed ought
less to neglect these instincts, which they discover moreover
in themselves, although their artificial method of living has
for the most part nearly effaced them ; the physician of his
own accord, indeed, has carefully observed it. Sympathy or
antipathy signifies that which in bodies destitute of feeling
corresponds to the instinct for union or separation found in
animals. And although we have no such knowledge of the
cause of these inclinations or tendencies, as is to be desired,
we nevertheless have a notion of them sufficient to discourse of
them intelligibly.
§ 9. Ph. The second remedy is that the ideas of the names
of the modes at least be determined and, § 10. that the ideas
of the names of substances be more conformed to what exists.
If any one says that justice is conduct conformed to the law
relating to the good of another, this idea is not sufficiently
determined, so long as we have no distinct idea of that which
is called law.
Th. We might say here that the laiu is a precept of wisdom
or of the science of happiness.
§ 11. Ph. The third remedy is to employ terms so far as
possible in conformity with received usage. § 12. The fourth
is to declare in what sense we take the words, whether we
coin new ones or employ the old in a new sense, (or)
whether we -find that use has not sufficiently fixed their mean
ing. § 13. But there is some difference. § 14. The words for
simple ideas which cannot be defined, are explained by synony
mous words, when they are better known, or by showing the
thing. It is by these means that we can make a peasant un
derstand what the color feuille morte is, by telling him that it is
that of dry leaves which fall in the autumn. § 15. The names
of the mixed modes should be explained by definition, for that is
possible. § 16. It is upon this ground that ethics is suscepti
ble of demonstration. We shall take man as a corporeal
CRITIQUE OF LOCKE [BK. in
rational being without troubling ourselves about his external
figure, § 17. for it is by means of definitions that the matters
of morality may be clearly treated. We shall rather define
justice according to the idea we have in our mind than
seek a model therefor outside of us, as Aristides, and form
it thereupon. § 18. And as the majority of the mixed
modes nowhere exist together, we can fix them in denning
them only by the enumeration of that which is scattered.
§ 19. In substances there are ordinarily some directing or
characteristic qualities which we consider as the most distinc
tive idea of the species, to which we suppose the other ideas
forming the complex idea of the species are attached. It is
form in vegetables and animals, and color in animate bodies,
and in some color and form together. This is why, § 20. the
definition of man given by Plato is more characteristic than
that of Aristotle ; or why we should not cause the death of
monstrous productions, § 21. and often sight avails as much
as any other test ; for persons accustomed to test gold often
distinguish by sight the true from the false, the pure from
that which has been adulterated.
Tli. Everything doubtless returns to the definitions which
may extend even to primitive ideas. One and the same sub
ject may have several definitions, but the knowledge that they
agree with themselves, must be learned by reason, by demon
strating one definition by another, or by experience, by proving
that they constantly go together. As for morality, one part is
wholly grounded in reason ; but there is another depending
upon experience and related to the disposition. For a knowl
edge of substances, form and color, i.e. the visible, gives us
the first ideas, because it is by these that we know things
at a distance ; but they are ordinarily too provisional, and in
things of importance to us we try to know substance more
closely. I am astonished, moreover, that you return again to
the definition of man, attributed to Plato, since you have just
yourself stated, § 16. that in morals man must be taken as a
corporeal rational being without troubling ourselves about the
external form. For the rest it is true that a large practice does
much for discerning at sight what another may scarcely know
through arduous experiments. And physicians of large experi
ence, with very good sight and memory, often know at the first
CH. xi] ON HUMAN UNDERSTANDING 393
appearance the disease which another will draw out for himself
with difficulty by force of questioning and trying the pulse.
But it is well to unite all the indications we may have.
§ 22. Ph. I admit that he to whom a good assayer makes
known all the qualities of gold, will have a better knowledge
of them than sight could give. But if we could learn its in
ternal constitution, the meaning of the word gold would be as
easily determined as that of the triangle.
Th. It would be wholly as determined, and it would have in
it no provisional element ; but it would not be so easily deter
mined. For I think a distinction a little prolix would be
necessary in order to explain the contexture of gold, as is the
case indeed in geometry with figures whose definition is long.
§ 23. Ph. Spirits separated from bodies have doubtless
knowledge more perfect than ours, although we have no notion
of the manner in which they may acquire it. But they may
have as clear ideas of the radical constitution of bodies, as we
have of a triangle.
Th. I have already remarked, sir, that I have reasons for
thinking that no created spirits exist entirely separate from
bodies ; but there are no doubt some whose organs and under
standing are incomparably more perfect than ours, and which
surpass us in every kind of conception, as much and more than
Mr. Freniele,1 or that Swedish boy of whom I have spoken to
you, surpassed the common run of men in the calculation of
numbers, made by imagination.
§ 24. Ph. We have already noticed that the definitions of
substances which may serve in explaining names are imperfect
in relation to the knowledge of things. For usually we put
1 Cf. Gerhardt, Leibniz, philos. ficJtrift., 4, 319. Bernard Fronicle de Bessy,
c. 1605-1G75, brother of the poet Nicolas Frenicle, KJOO-KJUl, " conseiller a la
cour des monnaies," member of the Paris Academy of Sciences, who acquired
the reputation of being the first arithmetician of his age by the rapidity with
which he solved the most complicated numerical problems, and by his ingen
ious researches upon the solution in whole numbers of indeterminate equations.
His method, known as the met/tod of exclusions, appears to have been an inge
nious groping, but based on some general propositions which greatly restricted
this groping, and which have since been rigorously demonstrated by Leonard
Euler, 1707-17<s:i and Jos. Louis Lagrange, 1736-1813. Pierre de Fermat, HSOl-
1»)()5, and Descartes. ir>!»u'-l(J50, greatly admired his work, astonished that he
could go so far without the aid of algebra and that his arithmetic could con
duct him where analysis finds so much difficulty in going. His principal work
was, Traite des triangles, rectangles en nombre, Paris, 1(>7<>. — Tu.
394 LEIBNITZ'S CRITIQUE OF LOCKE [BK. m
the name in the place of the thing ; then the name says more
than the definitions ; thus to give a good definition of sub
stances, we must study natural history.
T/i. You see then, sir, that the name gold, for example,
signifies not only that which he who pronounces it knows of
it, — for example, something yellow, very heavy, — but also
what he does not know, and which another may know, i.e. a
body endowed with an internal constitution from which pro
ceed color and weight, and from which spring still other prop
erties admitted to be better known by experts.
§ 25. Ph. It were now to be wished that those practised in
physical researches would set down the simple ideas in which
they observe that the individuals of each species constantly
agree. But the composition of a dictionary of this kind
which would contain, so to speak, a natural history, would re
quire too many persons, too much time, trouble, and sagacity
for such a work ever to be hoped for. It would be well, .how
ever, to accompany words with small copper-plate engravings
of things known by their external form. Such a dictionary
would be of much service to posterity and would spare future
critics much trouble. Small figures as of the celery -plant
(apinm), of a Bouquetin (ibex, a kind of wild goat), would be
more valuable than long descriptions of this plant or of this
animal. And in order to know what the Latins called strigiles
and sistrum, tunica and pallium, figures in the margin would be
incomparably more valuable than the pretended synonymes,
currycomb, cymbal, dress, cloak, mantle, which show but little
of them. For the rest I shall not stop upon the seventh remedy
of the abuse of words which is to employ constantly the same
term in the same sense, or to give notice when you change it.
For we have spoken sufficiently of this subject.
Tli. Eev. Father Grimaldi,1 President of the Mathematical
1 Claudius Philip Grimaldi, with whom Leibnitz became acquainted during
his stay in Rome in 1(589, and with whom he corresponded, receiving from him
after his return to Pekin much interesting information. (Jf. Guhrauer, G. W.
Frelherr v. Leibniz, 2, 95 sq. ; Kuno Fischer, Gesch. <l. n. Philos., Vol. 2, p. 201,
3d ed., Heidelberg, 1889; Dutens, Leibniz, op. om., 4, Pt. I. 81, 83 «<?., 88; (5,
10(5, 128, 227, Gerhardt, Leibniz, philon. Schrift. 3, 1(5(5, 174. Schaarschmidt
states that such dictionaries as Leibnitz here mentions on the authority of
Grimaldi exist in fact among the Chinese, and have been brought to Europe,
that the Bonn University library possesses a couple of parts of one such
dictionary, and that it must be regarded as an alphabetically arranged orb in
pictus. — TR.
en. xi] ON HUMAN UNDERSTANDING 395
Society at Pekin, tells me that the Chinese have illustrated
dictionaries. There is a small nomenclator printed at Nurem
berg in which there are such figures for each word which are
good enough. Such an illustrated universal dictionary were to
be desired, and would not be very difficult to make. As for the
description of species, it is properly natural history, and we
are working at it by degrees. Were it not for the wars
(which have troubled Europe since the first foundation of the
Societies or Royal Academies) it would be farther advanced,
and already in a condition to profit from our labors ; but the
great for the most part do not recognize its importance, nor
what good they deprive themselves of by neglecting the ad
vancement of solid knowledge ; and besides they are ordinarily
too much indisposed by the pleasures of peace or by the cares
of war to weigh things which do not strike them at once.
ESSAY ON UNDERSTANDING
BOOK IV. — OF KNOWLEDGE
CHAPTER I
OF KNOWLEDGE IX GENERAL
§ 1. Ph. Hitherto we have spoken of ideas and of ivords
which represent them ; let us come now to the knowledge,
which the ideas furnish, for it rests only upon our ideas.
§ 2. Knowledge is simply the perception of the connection
and agreement, or of the opposition and disagreement, which
we find between two of our ideas. Whether we imagine, con
jecture, or believe, it is always that. We perceive, for exam
ple, by this means, that white is not black, and that the
angles of a triangle and their equality to two right angles
have a necessary connection.
Th. Knowledge has a still more general signification, so
that we find it also in ideas or terms, before we reach proposi
tions or truths. And it may be said that he who has atten
tively looked at more pictures of plants and animals, more
diagrams of machines, more descriptions or representations of
houses or fortresses, who has read more ingenious romances,
heard more curious narratives, this one, I say, will have more
knowledge than another, even though there should not be a
word of truth in all that which was portrayed or related to
him ; for the custom he -has of representing in his mind many
express and actual conceptions or ideas, renders him more fit
to conceive what is placed before him ; and it is certain that
lie will be better instructed and more capable than another
who has neither seen nor read nor heard anything, provided
-°>97
398 LEIBNITZ'S CRITIQUE OF LOCKE [HK. iv
that in these stories and representations he takes nothing as
true which is not so and that these impressions do not prevent
him elsewhere from distinguishing the real from the imagi
nary, or the existent from the possible. This is why certain
logicians of the period of the Reformation who were in some
measure of the party of the Ramists,1 were not wrong in say
ing that the topics or orders of invention (argumenta, as they
call them) serve as much for the explication or very detailed
description of an incomplex theme, i.e. of a thing or idea, as
for the proof of a complex tlieme, i.e. of a thesis, proposition, or
truth. And indeed a thesis may be explained, in order that
its sense and force may be well known, without raising the
question of its truth or proof, as is seen in sermons and homi
lies explaining certain passages of Holy Scripture, or in
instruction or lectures upon certain texts of civil or canon law
whose truth is presupposed. We can even say that there are
some themes which are means between an idea and a proposi
tion. These are the questions, some of which demand only yes
or no ; and they are the nearest to propositions. But there
are some also which demand the how, the circumstances, etc.,
where there is more to be supplied in order to make proposi
tions. It is true, it may be said, that in descriptions2 (even of
things purely ideal) there is a tacit affirmation of possibility.
But it is also true that, as we may undertake the explanation
and proof of a falsehood, a method which sometimes serves as
its best refutation, the art of description may fall upon the
impossible also. Something like this is found in the novelle
of the Count of Scandiano followed by Ariosto,3 and in the
1 The Ramists were disciples of Peter Ramus (cf. infra p. 408, note 1).
Sehaarsohmidt states that Leibnitz probably has in mind chiefly J. H. Alsted,
whom he has previously (cf. ante, pp. 311, note 2, 362) cited, and whom lie
greatly prized and studied, in whose Systema lor/icse harmonicum, Her-
borniae, 1614, p. 69, the argitmentum is divided into argumentum simplex
(which Leibnitz calls theme incomplete] and into argumentum complexnm.
The former, according to Alsted, is a "terminus extra omnem dispositionem
diria:ens materiam " (Leibnitz says: " une chose ou idee"), the latter is a
" definitio et distributio " (Leibnitz says : " une these, proposition ou ve'rite ") .
C/. Alsted, p. 261. — TB.
2 I.e. in the sense of nominal definitions, which allow the really impossible.
Cf. ante, p. 317, note 3. — TR.
3 Leibnitz here refers to Matteo Maria Boiardo, c. 1434-1494, Count of
Scandiano, and the author of Orlando Innamorato, which a recent writer
calls "the most chivalrous poem of the Renaissance," and "a masterpiece of
CH. il ON HUMAN UNDERSTANDING 399
"Amadis of Gaul " l or other old romances, in the fairy-stories
which were again in fashion some years since, in the "True
History"2 of Lucian and in the "Voyages" of Cyrano de
Bergerac ; 8 to say nothing of the grotesque figures of the
painters. So we know stories with the rhetoricians belong in
the number of progymnasmata or preliminary exercises. But
taking knowledge in a narrower sense, i.e. as knowledge of
invent! ve^enius," and which furnished Ludovico Ariosto, 1474-1533, with the
theme of his Orlando Furioso. For an account of the two writers and their
works, cf. J. A. Symonds, Renaissance in Italy, Ft. IV., Italian Literature,
Vol. 1, pp. 450 sq., Vol. 2, pp. 1 sq. New York, H. Holt & Co., 1885.
Through a misunderstanding of Leibnitz's reference to the Count of Scan-
diano, Schaarschmidt, in his note to the passage, has wrongly identified him
with Tito Giovanni Ganzarini, 1518-1582, Professor of Literature at Modena,
called il Scandianese, from his birthplace, Scandiano. Ariosto published his
Orlando Furioso in 15 16, two years before Ganzarini. was born, and could
scarcely be said to have "followed" an author who was only fifteen years
old when the poet himself died. — TR.
1 The Amadis de Gaula, the best of all the old romances of chivalry, was
originally written, it is supposed, about 131)0, by Vasco de Lobeira, a Portu
guese knight attached to the coxirt of John I. of Portugal, and who died in 1403.
The oldest text now extant is in Spanish prose, a version from the Portuguese
original, now lost, made by Garcia Ordonez de Montalvo, between 1402 and
1504. Editions of the Spanish version are numerous, the earliest accessible
being that of 1519; and there are translations in English, French, German,
Italian, and other languages. The best and at present the only readable
edition in English is the abridged translation (with a Preface giving an
account, not, however, without error, of the work), made from the Spanish,
by Robert Southey, London, 1803, 4 vols., 12mo, new ed., London, 1872, 3 vols.,
Kimo. Cf. also, V. de Lobeira, Amadis de Gaula, Barcelona, 1847-8, 4 vols.,
lOmo; George Ticknor, Hist, of Spanish Lit., 3d ed., Boston, 1863, Vol. 1,
pp. 1!)8-207; L. Braunfels, Kritischer Versuch iiber Amadis, Leipzig, 1876.
It may be added that the writer of the article, "Amadis of Gaul," in the
Encyclop. Brit., 9th ed., argues for the Anglo-Norman origin of the romance,
on the ground that all its ideas and materials, its design and machinery,
belong to the Anglo-Norman romance-cycle in vogue before Lobeira was
born. — TR.
2 The 'AArjOoOs io-ropia? Aoyo? ( VerfB Historise) of Lucian is one of the witty
satirist's cleverest works, written in easy and elegant Greek, and exhibiting
great fertility of invention. It was purposely composed, says Lucian, as a
satire on the poets and logographers who have written so many marvellous
tales, and contains things which neither he nor any one else has ever seen,
which not only do not, but cannot, exist, and descriptions of experiences and
adventures which are absurd and impossible, chief among which is a voyage
to the moon. Lucian himself says that the only true statement in his History
is that it contains nothing but lies from beginning to end. It has without doubt
supplied hints to, or served as a model for, writers like Rabelais, Swift, and
Cyrano de Bergeran. — TR.
3 Cf. ante, p. 228, note 2. Amid many imaginative extravagances, these
Voyaues contain a pretty exact knowledge of the philosophy of Descartes. — TR.
400 LEIBNITZ'S CRITIQUE OF LOCKE [UK. iv
truth, as you, sir, do here, I say it is quite true that truth is
always grounded in the agreement or disagreement of ideas,
but it is not true in general that our knowledge of truth is a
perception of this agreement or disagreement. For when we
know truth only empirically, from having experienced it,
without knowing the connection of things and the reason
there is in what we have experienced, we have no perception
of this agreement or disagreement, unless we mean that we
feel it in a confused way without being conscious of it. But
your examples, it seems, show that you always demand a knowl
edge in which one is conscious of connection or opposition,
and this is what cannot be granted you. Further, we can
treat a complex theme not alone by seeking the proofs of its
truth, but also in explicating and otherwise illustrating it,
according to the topical order, as I have already observed.
Finally, I have a further remark to make upon our definition :
viz. that it appears only suited to categorical truths, in which
there are two ideas, the subject and the predicate ; but there
is besides a knowledge of hypothetical truths or what may be
reduced thereto (as disjunctives and others) in which there is
connection between the antecedent and the consequent propo
sition ; thus more than two ideas may enter therein.
§ 3. Ph. [Let us limit ourselves here to the knowledge of
truth and then apply what will be said of the connection of
ideas to the connection of propositions, in order to include in
one whole the categorical and hypothetical truths.] Xow I
believe that this agreement or disagreement may be reduced
to four kinds : (1) Identity or diversity, (2) Relation, (3) Co
existence or necessary connection, (4) Real existence. § 4.
For the mind perceives immediately that one idea is not an
other, that white is not black ; § 5. then it perceives their
relation by comparing them with each other; for example,
that two triangles whose bases are equal and which are found
between two parallels are equal. § C. Xext there is coexist
ence (or rather connection), as fixedness always accompanies
the other ideas of gold. § 7. Finally there is real exist
ence beyond the mind, as when it is said : God is.
Th. I believe it may be said that the connection is nothing
else than the agreement or the relation taken generally. And I
have remarked above that every relation is either of com-
CH. i] ON HUMAN UNDERSTANDING 401
parison or concurrence. That of comparison gives diversity
and identity, either complete or partial ; whereby are consti
tuted the concepts of the same or the diverse, the like or unlike.
Concurrence contains what you call coexistence, i.e. connection
of existence. ,But when we say that a thing exists or that it
has real existence, this existence itself is the predicate, i.e.
it has a notion joined with the idea in question, and there is
connection between these two notions. The existence of the
object of an idea may also be conceived, as the concurrence of
this object with the Ego. Thus I believe it may be said that
there is only comparison or concurrence ; but that the com
parison which marks identity or diversity, and the concurrence
of the thing with the Ego, are the relations which deserve to
be distinguished among others.1 More exact and more pro
found researches might perhaps be made ; but I content myself
here with making remarks.
§ 8. Ph. There is actual knowledge, which is the present
perception of the relation of ideas ; and there is habitual
knowledge, when the mind has so evidently perceived the
agreement or disagreement of ideas, and so placed it in its
memory, that every time it comes to reflect upon the proposi
tion, it is at once certain of the truth it contains Avithout the
least doubt. For being capable of thinking clearly and dis
tinctly of but one thing at once, men would all be very igno
rant if they knew only the actual object of their thoughts ;
and he who knew most would know but one truth.
Tli. It is true that our science, the most demonstrative in
deed, being very often obliged to acquire its existence by a
long chain of inferences, must involve the memory of a past
demonstration which is no longer distinctly in view, when the
conclusion is made ; otherwise it would always be repeating
this demonstration. And even while it lasts it cannot be
understood as a complete whole at once ; for all its parts can
not be present in the mind at the same time ; thus always re
calling the preceding part to mind, we should never advance to
the last which achieves the conclusion. This is the reason also
1 Leibnitz reduces Locke's four kinds of agreement or disagreement to two,
and thus generalizes the relation and considers the existence as th<^ concur
rence of the object with the Ego. This concurrence Leibnitz explains by his
doctrine of pre-established harmony. — TK.
402 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
that without writing it would be difficult properly to establish
the sciences, the memory not being sufficiently reliable. But
having put in wrriting a long demonstration, like, for example,
those of Apollonius,1 and having gone over again all its parts,
as if they were examining a chain, link by link, men can
assure themselves regarding their reasonings ; for which pur
pose proofs are also of use, and the result at last justifies the
whole. But we see by this that as all belief consists in the
memory of past life, of proofs or reasons, it is not within our
power or choice to believe or disbelieve, since memory is not
a thing depending on our will.
§ 9. Ph. It is true that our habitual knowledge is of two
sorts or degrees. Sometimes, truths laid up as it were in the
memory no sooner present themselves to the mind, than it sees
the relation between the ideas entering therein ; but, some
times, the mind contents itself with the memory of the convic
tion, without retaining the proofs, and often, indeed, without
the power' to recall them if it wished. It may be thought that
this is rather to believe one's memory than really to know the
truth in question, and this formerly appeared to me to be a
mean between opinion and knowledge, a kind of assurance
superior to simple belief based upon the testimony of another.
But upon due reflection I find that this knowledge contains
perfect certainty. I remember, i.e. I know (memory being-
only the reviving of something past), that I was once certain
of the truth of this proposition, that the three angles of a tri
angle are equal to two right angles. Xow, the immutability
of the same relations between the same immutable things
is at present the mediate idea which shows me that, if they
were once equal, they will be so still. It is upon this ground
that in mathematics particular demonstrations furnish general
knowledge ; otherwise a geometer's knowledge would not ex
tend beyond this particular figure which he had drawn while
demonstrating it.
Th. The mediate idea of which you, sir, speak, presupposes
the fidelity of our memory ; but it sometimes happens that our
memory deceives us, and that we have not made every neces
sary effort, although we now believe we have. This is clearly
seen in the examination of accounts. Sometimes there are
1 Cf. ante, p. 108, note 1. — TR.
en. ij ON HUMAN UNDERSTANDING 403
examiners officially appointed, as at our mines in the Harz,
and to make the receivers of the particular mines more atten
tive, they have imposed a money penalty upon every error in
calculation ; nevertheless they find them in spite of this pen
alty. But the more care we employ, the more reliance we can
place upon past reasonings. I have devised a method of keep
ing accounts, by which he who collects the sums of the col
umns leaves upon the paper traces of the progress of his
reasoning, so that he does not reason in vain. He can always
revise and correct the last errors without affecting the first :
the examination, also, which another desires to make costs, in
this way, almost no trouble, because he can examine the very
same traces at a glance. There are, besides, means of verifying
the accounts of each article, by a very convenient kind of proof,
without increasing to any considerable extent the labor of the
computation. And all this easily shows that men may have
rigorous demonstrations on paper, and have an infinite number
of them. But unless we remember that we have been abso
lutely accurate, we cannot have this certainty in the mind.
And this accuracy consists in an orderly procedure, the observ
ance of which in each part is an assurance as regards the
whole ; as in the examination of a chain by links, in which
inspecting each to see if it is strong, and measuring with the
hand so as not to skip any, assurance is obtained of the good
quality of the chain. And by this means we have all the
certitude of which human things are capable. But I do not
agree that in mn.tliem&tics .particular demonstrations upon the
figure which is drawn furnish this general certitude, as you
seem to take it. For you must know that it is not the figures
which furnish the proof with geometers, although the style of
the exposition may make you think so. The force of the dem
onstration is independent of the figure drawn, which is drawn
only to facilitate the knowledge of our meaning, and to fix the
attention; it is the universal propositions, i.e. the definitions,
axioms, and theorems already demonstrated, which make the
reasoning, and which would sustain it though the figure were
not there. Hence it is that a learned geometer, like Scheube-
lius,1 has given Euclid's figures without the letters which might
1 Johann Scheybl — Latin, Scheubelius — 1494-1570, was, according to Jo'cher,
Allf/cmeines GelcJirten-Lcxicon, Leipzig, 1750-51, Vol. 4, p. 257, a professor
404 LEIBNITZ'S CRITIQUE OF LOCKE [,JK. iv
bind them to the demonstration he has put with them; and
another, like Herlinus,1 has reduced the same demonstrations
to syllogisms and prosyllogisms.
CHAPTER II
OF THE DEGREES OF OUR KNOWLEDGE
§ I. Ph. Knowledge is then intuitive when the mind per
ceives the agreement of two ideas immediately by themselves
without the intervention of any other. In this case, the mind
takes no pains to prove or examine the truth. As the eye
sees the light, the mind sees that white is not black, that a
circle is not a triangle, that three is two and one. This knowl
edge is the clearest and most certain of which human weak
ness is capable; it acts in an irresistible manner without
allowing the mind to hesitate. It is knowledge that the idea
is in the mind as perceived. Whoever asks for greater certi
tude, knows not what he asks.
Th. Primitive truths, which are known by intuition, are of
two kinds, like the derivative. They are truths of reason or
truths of fact. Truths of reason are necessary, and those
of fact are contingent. The primitive truths of reason are
those which I call by the general name of identical, because
they seem only to repeat the same thing without giving us any
information. They are affirmative or negative. The affirma
tive are such as the following : Each thing is ivhat it is. and in
of mathematics in the University at Tubingen. His Eudidis sex libri primi
c!<> f/cometricis principiis yr. et fat. cum commentario appeared at Basle, 1590.
— TR.
1 Christian Herlinus. whom Leibnitz also mentions toward the end of his
Meditationes de Co;/., Verit., et Idcin, as co-editor with Conrad Dasypodius
(1532-1000, professor of mathematics in Strassburg University, and Canon
of St. Thomas' Church) of Euclid, appears to be otherwise unknown. Their
joint work, of which Herlinus did the first and fifth books, and Dasypodius
the other four, appeared under the title Aix/lt/*!* f/coniptrt'iv ses Ubrorum
EudidiK, etc., Strassburg, 15(><>, fol. It is, says Michaud, Hint/. Unirertdlf,
Vol. 10, p. 5()0, a pedantic work in which the demonstrations of the Greek
geometer are reduced to syllogistic form, so that a proposition of fifteen or
twenty lines is spun out into several pages, and is often more involved or
at least more difficult to follow. — Tit.
cir. ii] ON HUMAN UNDERSTANDING 405
as many examples as you please, A is A, B is B. I shall
be what I shall be. I have written what I have written. And
nothing in verse as in prose, is to be nothing or a trifle. The
equilateral rectangle is a rectangle.1 The rational animal is al
ways an animal. And in the hypothetical: If the regular figure
of four sides is an equilateral rectangle, this figure is a rectangle.
Copulatives, disjunctives, and other propositions are also sus
ceptible of this identicism, and I reckon indeed among the
affirmatives : non-A is non-A. And this hypothetical : if A is
non-B, it follows that A is non-B. Again, if non-A is BC, it
follows that non-A is BC. If a figure having no obtuse a.ngle
may be a regular triangle, a figure having no obtuse angle may be
regular. I come now to the identical negatives which belong
either to the principle of contradiction or to the disparates.
The principle of contradiction is in general : a proposition is
either true or false : this contains two true statements, one that
the true and the false are not compatible in one and the same
proposition, or that a proposition cannot be true and false at
once ; the other that the opposition or the negation of the true
and the false are not compatible, or that there is no mean be
tween the true and the false, or rather : .it is impossible for a
proposition to be neither true nor false. Xow all this is also
true in all imaginable propositions in particular, as ichat is A
cannot be non-A. Again,2 AB cannot be non-A. An equilat
eral rectangle cannot be non-rectangle. Again, it is true that
every man is an animal, then it is false that any man is found
who is not an animal. We may vary these statements in many
ways, and apply them to copulatives, disjunctives, and others.
As for the disparates, they are the propositions which state
that the object of one idea is not the object of another idea ;
as. that heat is not the same thing as color; again, man and
animal are not the same, although every man is an animal.
All this may be asserted independently of all proof or of re
duction to opposition, or to the principle of contradiction.
1 Erdmnnn and Jacques omit: "Est un rectangle. L'animal raisonnable
est tou jours un animal. Et dans les hypothetiques: Si la figure reguliere de
quatre costes est un rectangle equilateral." — Tn.
- Erdmaim and Jacques omit: "Item AB ne sauroit estre non-A. Un
rectangle equilateral ne sauroit estre non-rectangle. Item il est vray que tout
liomme est un animal, done il est faux,'' and instead of the last four words,
read : " Item il est vrav,'' etc. — Tu.
406 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
when these ideas are sufficiently understood not to require
here analysis ; otherwise they are liable to be misunderstood :
for in saying, the triangle and the trilateral are not the same, we
should be mistaken, since upon proper consideration we find
that three sides and three angles always go together. In say
ing, the quadrilateral rectangle and the rectangle are not the same,
we should also be mistaken. For it is found that the four-
sided figure alone can have all the angles right angles. But
we may also say in the abstract that the triangle is not the tri
lateral, or that the formal causes of the triangle and of the tri
lateral are not the same, as the philosophers express it. They
are different relations of one and the same thing.
Some one after having heard with patience what we have
just said up to this point, will lose it after all and will say
that we are amusing ourselves with frivolous statements,. and
that all identical truths are useless. But he will make this
judgment for want of having thought sufficiently upon these
matters. The deductions of logic, for example, are demon
strated by identical principles ; and geometers require the
principle of contradiction in their demonstrations which re
duce to the impossible.1 Let us be content here to show the
use of identicals in the demonstrations of rational deduction.
I say, then, that the principle of contradiction alone suffices to
demonstrate the second and the third figures of the syllogism
by means of the first. For example, we may conclude in the
first figure, in Barbara :
All B is C,
All A is B,
Then All A is C.
Suppose that the conclusion is false (or that it is true that
some A is not C), then one or the other of the premises will
be false also. Suppose that the second is true, the first must
then be false, which maintains that all B is C. Then its con
tradictory will be true, i.e. some B will not be C. And this
will be the conclusion of a new argument, drawn from the
1 I.e. the so-called indirect proof, which provisionally assiunes the truth of
the contradictory opposite of the proposition to be proved, and then, having
discovered the impossibility of this assumption, concludes, by the aid of the
principle of contradiction, that the original proposition is correct. — TR.
en. n] ON HUMAN UNDERSTANDING 407
falsity of the conclusion and the truth of one of the premises
of the preceding argument. Here is this new argument :
Some A is not C.
This is opposed to the preceding conclusion supposed false.
All A is B.
This is the preceding premise supposed' true.
Then some B- is not C.
This is the present true conclusion, opposed to the preced
ing false premise.
This argument is in the mode Disamis of the third figure,
which is thus plainly demonstrated and at once from the
mode Barbara of the first figure by employing simply the prin
ciple of contradiction. And I noticed in my youth, when I
examined minutely these things, that all the modes of the
second and third figure may be drawn from the first by this
method alone, by supposing that the mode of the first is valid,
and consequently that the conclusion being false, or its contra
dictory being taken as true, and one of the premises being
taken as true also, the contradictory of the other premise is
true. It is true that in the schools of logic they prefer to
make use of conversions to draw the less principal figures from
the first which is the principal, because this method appears
better suited to the scholars. But for those who seek demon
strative reasons, in which the least possible suppositions must
be employed, we shall not demonstrate by the supposition of
conversion what may be demonstrated by the primitive princi
ple alone, which is that of contradiction and which assumes
nothing. I have also made this apparently remarkable obser
vation, that only the less principal figures which are called
direct, viz. the second and the third, can be demonstrated by
the principle of contradiction by itself: but the less original
indirect figure, the fourth, whose invention the Arabs attribute
to Galen,1 although we found nothing concerning it in the
1 Claudius Galemis, c. 130-c. 201, a very celebrated physician and medical
writer, who also wrote a large number of philosophical and logical works, the
greater part of which are now lost. His medical and scientific treatises contain
considerable philosophical and logical discussion, and his De nsu partium
408 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
works of his remaining to us, nor in the other Greek authors,
the fourth, I say, has this disadvantage, that it cannot be
derived from the first or principal figure by this method
alone, and it is necessary besides to employ another supposi
tion, viz. conversions, so that it is farther removed by one
degree than the second and the third, which are on a level
and equally removed from the first ; while the fourth needs
also the second and the third for its demonstration. For it is
found very opportunely that the conversions required are
demonstrated by the second or third figure, demonstrable
independently of the conversions, as I have just shown. It is
Peter Kamus 1 who already made this remark concerning the
demonstrability of conversion by these figures ; and (if I am
not mistaken) he reproached the logicians, who make use of
conversion to demonstrate these figures, with arguing in a
circle, although it was not so much the circle that he found it
necessary to reproach them with (for they did not use these
corp. hum. is, says Janet, " an apology for and a continual application of the
principle of final causes." The most complete ed. of his works containing
the Greek text and a Latin version is the Opera Omnia, cur. C. G. Kiihn,
Leipzig, 1821-:;:;. 20 vols., 8vo. For his philosophical views, cf. K. Sprengel|
Jldtr.z. Gesch. d. Medicin, 1, 117-195, Halle, 1794-(>; on his logic, cf. Prantl,
GescJi. d. Loyik, 1, 559-577. A brief account of his philosophy is given by
Zeller, Philos. d. Griech., III., 1 [Vol. 5], 823 sq., 3d ed., Leipzig, 1880.
The invention of the fourth syllogistic figure was ascribed to Galen by
Averroes, 1105-1198, but without adequate foundation. Galen was led through
the additions to the first figure already made by Theophrastus, c. 373-c. 288
B.C., to transpose the premises in the same, and only by this means indirectly
to the fourth arrangement of the middle term. (Jf. Prantl, Gesch. d. l^x/ik
im Abendlande, 1, 570-574 ; also Sir W. Hamilton, Lects. on Lo//ic, Boston, 187.'!,
Lect, XX., 1[ LXXIIL, pp. 285-6; Lect. XXL, ^ LXXIV., p. 302-3, and notes.
- TR.
1 Petrus Ramus — Pierre do la Ramee — 1515-1572, murdered during St.
Bartholomew's Night, was a determined opponent of Aristotelian scholasticism,
and especially of its logic or dialectic, in the place of which lie attempted to
set up a new, simpler, and better grounded dialectic. For this purpose he
wrote and published his two works, Animadversiones Arhtoteliess, Par-is,
1534, etc., and Insti.tutiones d'udecAicx, Paris, 1543. Following Cicero and
Quintilian, his scheme was a blending of logic and rhetoric. For a long time
after him, logicians were divided into Kamists and Anti-Ramists, while the
Semi-Ramists, among whom were Alsted and Goclen (cf. ante, p. 311, nole 2),
sought to mediate between the Aristotelic dialectic, as set forth by Melanch-
thon, and that of Ramus. The remarks to which Leibnitz here refers are
found, according to Schaarschmidt, in Am mad. Aristotel., Lutetife, 1548,
pp. 388 sq. For a good account of Ramus, cf. Stockl, Gesch. d. Philos. d.
MittP.laltprs,III. [Vol. 4], pp. 29(> sq.; also Uebe'rweg-Heinze, Gexch. d. Philus.,
7th ed., 3, 24, 2(5. —Tit.
CH. n] ON HUMAN UNDERSTANDING 409
figures in their turn to justify the conversions) as the hysteron
proteron or the reversal (le rebours}-, because conversions need
rather to be demonstrated by these figures, than these figures
by the conversions. But as this demonstration of conversions
shows also the use of the identical affirmatives, which many
take as altogether frivolous, it will be so much more to the
purpose to introduce them here. I wish to speak only of con
versions without contraposition, which suffice me here, and
which are simple or per accidens, as they are called. Simple
conversions are of two kinds : that of the universal negative,
as : 710 square is obtuse-angled, then no obtuse-angled figure is a
square; and that of the particular affirmative, as : some tri
angles are obtuse-angled., then some obtuse-angled figures are
triangles. But conversion per accidens, as it is called, concerns
the universal affirmative, as : every square is a rectangle, then
some rectangles are squares. A rectangle is here always under
stood to be a figure all of whose angles are right angles, and
by the square is understood a regular quadrilateral. Kow the
question is to demonstrate these three kinds of conversion,
which are :
(1) No A is B, then no B is A.
(2) Some A is B, then some B is A.
(3) All A is B, then some B is A.
Demonstration of the first conversion in Cesare, which
belongs to the second figure.
No A is B.
All B is B.
Then no B is A.
Demonstration of the second conversion in Datisi, which be
longs to the third figure.
All A is A.
Some A is B.
Then some B is A.
Demonstration of the third conversion in Darapti, which
belongs to the third figure.
All A is A.
All A is B.
Then some B is A.
410 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
This shows that the purest and apparently most useless
identical propositions are of considerable use in the abstract
and general; arid that may teach us that we should not
despise any truth. As for this proposition, that three is as
much as two and one, which you, sir, still adduce as an example
of intuitive knowledge, I have to say that it is only the defini
tion of the term three, for the simplest definitions of numbers
are formed in this way : Two is one plus one, three is two plus
one, four is three plus one, etc. It is true that there is therein
a concealed statement, which I have already spoken of, viz.
that these ideas are possible : and this is here known intuitively,
so that it may be said, that an intuitive knowledge is comprised
in definitions when their possibility appears at once. And in
this way all adequate definitions contain primitive truths of
reason and consequently intuitive knowledge. In short, you
can say in general that all primitive truths of reason are imme
diate with respect to an immediateness of ideas.
As for the primitive truths of fact, they are the immediate in
ternal experiences of an immediateness of feeling. And here it
is that the first truth of the Cartesians or of St. Augustine : 1
think, therefore I am, i.e. I am a thing which thinks, holds good.1
But we must know, that as the identicals are general or par
ticular, and as one is as clear as the other (since the statement
that A is A is as clear as the statement that a thing is what it
is), so is it also with the first truths of fact. For not only is
it immediately clear to me that / think, but it is wholly as
clear to me that / have different thoughts, that sometimes / think
of A, and sometimes of B, etc. Thus the Cartesian principle
is valid, but it is not the only one of its kind. You see by
this that all primitive truths of reason or of fact have this
in common, that they cannot be proved by anything more cer
tain.
§ 2. Ph. I am very glad, sir, that you have carried forward
1 Cf. Augustine, Solil. II., 1: " Tu qui scis te nosse, scis te esse? Scio!
Undescis? Neseio! Simplicem te sentis an multiplicem? Nescio! Cogitare
te scis? Scio!" in Opera, Vol. 1, p. 369, Benedictine ed., Paris, Franciscus
Muguet, 1679; Vol. 1, p. 885, ed. Migne, Paris, 1841. Augustine, 354-430, thus
anticipated the principle of Descartes, 1596-1650, " Cogito ergo sum," a fact
unknown however to Descartes, who was not one of the class of reading
philosophers, until brought to his knowledge by Arnauld, 1612-1694, and
Mersenue, 1588-1648, in their criticism of his philosophy. — TR.
en. 11] ON HUMAN UNDERSTANDING 411
farther than I had done that which relates to intuitive knowl
edge. Now demonstrative knoidedge is only a concatenation of
intuitive knowledge in all the connections of mediate ideas.
For often the mind cannot unite, compare, or apply immedi
ately the ideas one to the other, and this compels it to make
use of other ideas (one or more) as means to the discovery of
the agreement or disagreement it seeks, and this is what we
call reasoning. As in demonstrating the three angles of a tri
angle to be equal to two right angles, it finds some other
angles which are seen to be equal both to the three angles of
the triangle and to two right angles. § 3. These intervening
ideas are called proofs, and the disposition of the mind to dis
cover them is called sagacity. § 4. And even when found,
this knowledge cannot be acquired without pains and atten
tion and by more than a single passing view ; for the mind
must enter upon a progression of ideas, made gradually and
by degrees, § 5. and there is doubt before the demonstra
tion. § 6. It is not so clear as the intuitive knowledge, as
the image reflected by several mirrors from one to another
grows more and more faint with each reflection, and is no
longer at once so recognizable especially by weak eyes. It is
the same with knowledge produced by a long train of proof.
§ 7. And although each step taken by reason in the demon
stration is intuitive knowledge or simple sight, nevertheless
as in this long train of proofs the memory does not so exactly
preserve this connection of ideas, men often take fallacies for
demonstrations.
Tli. Besides natural sagacity or that acquired by exercise,
there is an art of finding mediate ideas (the medium), and this
art is analysis. Now it is well to consider here, that the ques
tion is sometimes to find the truth or falsehood of a given
proposition, which is nothing else than an answer to the ques
tion An? i.e. whether it is or is not. Sometimes it concerns
an answer to a more difficult (cceteris paribus) question, where
it is asked for example by whom and how ? and where there is
more to be supplied. And it is these questions alone, which
leave a part of the proposition blank, which the mathemati
cians call problems. As, when we are asked to find a mirror
which collects all the rays of the sun in one point, we are
asked for its form, or how it is made. As for the first ques-
41:2 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
tions in which the point at stake is only truth and falsehood
and where there is nothing to be supplied in the subject or
predicate, there is less invention, yet there is some, and the
judgment alone is not sufficient. It is true that a man of judg
ment, i.e. one who is capable of attention and reserve, and
who has the leisure, the patience, and the necessary freedom
of mind, may understand the most difficult demonstration if
properly set before him. But the most judicious man in the
world, without other aid, will not always be capable of discov
ering this demonstration. Thus there is still some invention
therein ; and with geometers there was more of it formerly
than now. For when analysis was less cultivated, more sagac
ity was necessary to attain it, and it is on this account that
some geometers still of the old school,1 or others who have not
yet sufficient aptness in the new methods, think they have
done something wonderful when they discover the demonstra
tion of some theorem that others have invented. But those
who are versed in the art of invention know when this is esti
mable or not ; for example, if some one sets forth the quadra
ture of a space comprised within a curved and a straight line,
which is successful in all its segments and wrhich I call general,
it is always within our power according to our methods to dis
cover its demonstration, provided we are willing to take the
trouble. But there are some particular quadratures of certain
portions, where the thing may be so involved, that it will not
always be possible (in potestate) thus far to develop it. It
happens also that induction presents us with truths in num
bers and in figures whose general reason is not yet discovered.
For much is needed in order to attain perfection of analysis in
geometry and in numbers, as many are becoming conceited
upon the basis of the boasts of some men otherwise excellent,
but a little too hasty or too ambitious.
But it is much more difficult to discover important truths,
and still more to discover means of producing what is sought,
when it is justly sought, than to discover the demonstration
of truths which another has discovered. Beautiful truths are
often attained by synthesis, by passing from the simple to the
complex; but when it is a question of discovering exactly the
means of producing what is proposed, synthesis is ordinarily
1 Gerhardt reads: " roche " ; Erdmann and Jacques: " race." — TB.
en. n] ON HUMAN UNDERSTANDING 413
not sufficient, and often to be willing to make all the requisite
combinations would be an endless task, although one might
often be aided therein by the method of exclusion,1 which cuts
off a good portion of useless combinations, and often nature
does not admit any other method. But the means are not al
ways at hand for the proper pursuit of this method. Analysis
then must give us a thread in this labyrinth, when it is possi
ble, for there are cases where the nature itself of the question
demands that we grope about, short cuts not being always
possible.
§ 8. Ph. ~Now as in demonstration intuitive knowledge is
always supposed, it has, I think, given occasion for this maxim :
that all reasoning springs from things already known and agreed
to (ex pruecognitis et prceconcessis} ? But we shall have occasion
to speak of the falsity of this axiom when we speak of the
maxims which are improperly taken as the foundation of our
reasoning.
Th. I am curious to learn what falsehood you can find in an
axiom apparently so reasonable. If it were always necessary
to reduce everything to intuitive knowledge, demonstration
would often be insufferably prolix. This is why mathema
ticians have had the cleverness to divide the difficulties and to
demonstrate separately the intervening propositions. And
there is art also in this; for as the mediate truths (which are
called lemmas, since they appear to be a digression) may be
assigned in many ways, it is well, in order to aid the under
standing and the memory, to choose those of them which
greatly shorten the process, and appear memorable and worthy
in themselves of being demonstrated. But there is another
1 The " method of exclusion " or elimination, says Schaarschmidt, proceeds
from a disjunctive judgment, the predicate of which embraces in the sum of
its divisional members all possible determinations of the subject. After it lias
been shown that individual divisional members cannot be united with the
subject in a categorical judgment, that one alone of the divisional members
wh'c'.i cannot be separated from the subject remains as the actual predicate
for the valid determination of the subject. For example: A is B, or C, or I),
or E. In this formula, B, C, 1), E must include all thinkable predicate-
determiuatioiis of A. In the question : Is A, B, or C, or D, or E, it is then
proved that A is not C, 1), E, in which case A must be B; or that A is not
B, D, E, in which case A must be C, and so on. — TK.
- Cf. Aristotle, Analljt. Post., I., 1, p. 71:v, 1: iraaa SiSao-Ka/V/a *ai -ratra /xaOrycris
6tai'orjTt/c»j e< TrpovCTap^oucrT/s •yiVtrai yvjjcreuis. — Tli.
4M LEIBNITZ'S CRITIQUE OF LOCKE [UK. iv
obstacle, viz. : that it is not easy to demonstrate all the axioms,
and to reduce demonstration wholly to intuitive knowledge.
And if we had chosen to wait for that, perhaps we should not
yet have the science of geometry. But we have already spoken
of this in our former conversations, and we shall have occasion
to speak of it again.
§ 9. Ph. We shall come to that presently ; now I shall re
mark again what I have already touched upon more than once,
that it is a common opinion that only the mathematical
sciences are capable of a demonstrative certainty ; but as the
agreement and disagreement which may be known intuitively
is not a privilege belonging only to the ideas of numbers and
figures, it is perhaps for want of application on our part that
mathematics alone have attained to demonstrations. § 10.
Many reasons conspired to this end. The mathematical
sciences are very generally useful ; the least difference therein
is very easily recognized. § II.1 These other simple ideas,
which are appearances or situations produced in us, have no
exact measure of their different degrees. § 12. 2 But when the
difference of these visible qualities, for example, is sufficiently
great to excite in the mind clearly distinct ideas, as those of
blue or red, they are as capable of demonstration as those of
number and extension.
Tli. There are notable examples enough of demonstration
outside of mathematics, and it may be said that Aristotle has
already given some in his "Prior Analytics." In fact logic is
as susceptible of demonstrations as geometry, and it may be
said that the logic of the geometers, or the methods of argu
mentation explained and established by Euclid in reasoning
upon propositions, are a particular extension or promotion of
general logic. Archimedes3 is the first, whose works we have,
who has practised the art of demonstration upon an occasion
where he is treating of physics, as he has done in his book on
1 § 11, as also § 12, is § 17 in the texts of Erdmann and Jacques. — TR.
2 § 12 is § 13 in Locke, Philox. Works, Vol. 2. p. 140 (Bonn's ed.). — TR.
3 Archimedes, 287-212 B.C., the greatest mathematician among the Greeks,
distinguished also for his discoveries in hydrostatics and hydraulics, and for
his ingenious inventions. He first placed the science of engineering upon a
sound mathematical hasis. The most complete and magnificent edition of his
extant works is that edited by Torelli and published at Oxford, at the Claren
don Press, 1792, fol. — TR.
OX HUMAN UNDERSTANDING 415
Equilibrium. Furthermore, jurists may be said to have many
good demonstrations; especially the ancient Roman jurists,
whose fragments have been preserved to us in the Pandects.
I am wholly of the opinion of Laurentius Valla,1 who cannot
enough admire these authors among others, because they all
speak in a manner so just and so clear and in fact reason in
a way closely approaching the demonstrative, and often it is
wholly demonstrative.2 Indeed, I do not know any science
outside that of law and that of arms, in which the Romans
have made any considerable addition to what they received
from the Greeks.
Tu regere imperio populos Romane memento :
Hse tibi erunt artes pacique imponere morem,
Parcere subjectis, et debellare superbos.3
This precise manner of expressing themselves is the reason
that all the jurists of the Pandects, though sometimes quite
1 Laurentius Valla — Lorenzo della Valle — c. 1407-1457, a humanist and
philologian of the earlier Italian Renaissance, was an earnest opponent of the
scholastic dialectic, a determined foe of tradition and authority, and the initi
ator and champion of a bold and unbiassed criticism which he applied to
language, historical documents, and ethical opinions. He was eminent as a
Latinist, and his treatise EleyantisB latinse, linyuss, c. 1431, in six books, —
the Preface to the third book of which Schaarschmidt thinks Leibnitz probably,
had in mind in referring to Valla's admiration for the style of the Roman
jurists, therein very highly praised, — subjected the forms of Latin grammar
and rhetoric to critical investigation and analysis, and established upon a
scientific foundation the principles of Latin style. His De /also credita et
cmcntita Constantini Donations, 1440, destroyed the claims of the Papacy to
temporal power based upon this alleged "Donation," by proving its docu
mentary foundations to be forgeries. His principal philosophical writings are :
l>e rolnptate et vero bono, 1431, in which he boldly defended the Epicurean
doctrine of pleasure as the true and only good; De lib pro nrbltrio ; and the
l)l(df.i-tlcsB disputationes contra Aristotelicox, 1499, of which Prantl, Gesrh.
<!. L«</ik tin Abcndlandp, 4, 101-1(57, gives some account with citations.
Valla's Opera Omnia, Basilire, 14(55 and 1540-1543. Leibnitz refers to him
and his DP lib. arbit. and De roluptafc in the Theodirep, Pt. TIL, §§ 405 .sr/.
For accounts of his life and works, cf. G. Tiraboschi. Stnrin della Letteratura
Italiana, Vol. (i, Pt. II., pp. 339-340, Rome, 1784; Symonds, Renrtissanre in
Jt<t>!f, Pt. II., The Revived of Learning, p. 258 sq., New York, H. Holt & Co.,
1881. For his philosophy, cf. Stock!, Gesch. (L Phflos. d. 3fittelal1r>r8, III.
[Vol. 4] , 279-283. Mancini published at Florence, 1891, a brilliant and exhaus
tive monograph investigating and settling disputed points in Valla's life. — TR.
2 Cf. Leibnitz's letter to Kestner, No. 15, in Ch. Kortholt, Leibnit. epixt.
nd (lirersos, Lipsiae, 1734-1742, Vol. 3, p. 250, Dutens, Lnbnit. opera omr/ia,
Vol. 4, Pt. III., p. 2(57, where lie expresses himself similarly as here. Also,
Guhrauer, T^ibn/z, pjn<> Biographic, Pt. I., pp. 30, 37. — TR.
3 Verg. &n. (5, 851-853. — TR.
416 LEIBNITZ'S CRITIQUE OF LOCKE [RK. iv
distant from one another in time, seem to be a single author,
and there would be much difficulty in distinguishing them, if
the names of the writers were not at the beginning of the ex
tracts ; as it would be difficult to distinguish Euclid,1 Archi
medes and Apollonius 2 in reading their demonstrations upon
matters which the one as well as the other has touched upon.
It must be admitted that the Greeks have reasoned with all
possible accuracy in mathematics, and that they have left the
human race models in the art of demonstration : for if the
Babylonians and the Egyptians had anything more than an
empirical geometry, nothing of it at least remains ; but it is
astonishing that these same Greeks lost it to such an extent 3
at once as soon as they turned aside ever so little from num
bers and figures in order to proceed to philosophy. For it is
strange that we do not see a shadow of demonstration in Plato
and in Aristotle (his "Prior Analytics" excepted) and in all
the other ancient philosophers. Proclus 4 was an excellent
geometer, but he seems another man when he speaks on phi
losophy. What has made it easier to reason demonstrably in
mathematics is largely the fact that experience can there guar
antee the reasoning at every moment, as is also the case in the
syllogistic figures. But in metaphysics and ethics this par
allelism of reason and experience is no longer found ; and in
1 Cf. ante, p. 93, note 1. — TR. 2 Cf. ante, p. 108, note 1. — TR.
3 A strange remark for Leibnitz to make, who had so thoroughly studied
Aristotle in his youth, and in later years Plato, whose works contain demon
strations inferior in no respect certainly to the precision of the Pandects. The
only explanations that seem to touch the case are that Leibnitz had in mind the
stringency and completeness of mathematical demonstration, which in form,
and sometimes in content also, is apparently, and sometimes really, superior,
though not necessarily so merely because mathematical, to the demonstrations
of philosophy ; or, as he seems to suggest in the immediately following con
text, that metaphysics being a matter of pure thought and ethics largely an
ideal not, as yet realized in the actual, their demonstrations cannot, like those
of mathematics, be experimentally verified, and must thus be regarded as, in
a sense, lacking in completeness as demonstrations. — TR.
4 Cf. ante, p. 108, note 2. Leibnitz's remark concerning Proclus has its
justification in the fact that his philosophical system, while embracing the
entire philosophy and theology of his predecessors methodically elaborated
with great dialectic art and skill, is yet purely formal in its completeness, its
thought exhibiting little freedom or creative power, and wholly lacking in any
real scientific basis and character. Though presenting here and there evidence
of deep speculative ability on the part of its author, his philosophy is never
theless wholly wanting in such demonstration as is found in his mathematical
work. — TR.
CH. n] ON HUMAN UNDERSTANDING 417
physics experiments demand labor and expense. Now men
at once relaxed their attention, and as a consequence were
led astray when they were destitute of this faithful guide,
experience, who aided and sustained them in their walk, as
that little revolving machine does, which prevents children
from falling when walking. There was a succedaneum,1 but it
is something that has not been and is not yet sufficiently con
sidered. And I shall speak of it in its place. For the rest,
blue and red are scarcely capable of furnishing matter for
demonstration by means of the ideas we have of them, because
these ideas are confused. And these colors do not supply
matter for reasoning so long as in experience they are found
accompanied by some distinct ideas, but in which the con
nection with their own ideas does not appear.]
§ 14. Ph. Besides intuition and demonstration, which are
the two degrees of our knowledge, all the rest is faith or
opinion, and not knowledge, at least as regards all general
truths. But the mind has also another perception, regarding
the particular existence of finite beings outside of us, and this
is sensitive knowledge.2
Tli. [Opinion, based on probability, deserves perhaps the
name knowledge also ; otherwise nearly all historic knowledge
and many other kinds will fall. But without disputing about
terms, I hold that the investigation of the degrees of probability
is very important, that we are still lacking in it, and that this
lack is a great defect of our logics.3 For if the question can
not always be decided absolutely, the degree of resemblance
ex datis can always be determined, and consequently one can
reasonably judge what view is the most likely. And when
1 I.e., a substitute. The expression was much used by the later Roman
jurists. — TR.
2 Locke's word is " sensitive," Philos. Wks. (Bonn's ed.), Vol. 2, p. 141, ad fin.
His three degrees of knowledge are intuitive, demonstrative, and sensitive, cf.
infra, p. 420. — TR.
3 Cf. Leibnitz's letter to Kestner, No. 11, Jan. 30, 1711, § 3 (Dutens, Leibnit.
op. am. 4, Ft. III., 2(i4, and Kortholt, Leibnit. epist. ad diversos, 3, 251) : " Ea
vero pars Logicae, qua sc. gradus verisimilitudinum et argumentorum pondera
constituerentur, nuspiam hactenus reperitur traditur. Ego juvenis aliquando
aggressus sum, sed per varia dissipatus, fere intra voluntatem steti. Topica
Aristotelis scopo meo non respondet. Congerit regulas, quse occasionem
aliquam pra^bere possunt de argumentis cogitandi, sed quse non possnnt
docere, quantum cuique argumento aut judicio ponderis insit." — TR.
418 LEIBNITZ'S CRITIQUE OF LOCKE [UK. iv
our moralists (I mean the wisest of them, such as the present
(moderne) General of the Jesuits)1 unite the safest and the most
probable, and prefer even the safe to the probable,- they are
not far in fact from the most probable ; for the question of
safety is here that of the little probability of an evil to be
feared. The fault of the moralists lax upon this article 3 has
largely been, that they have had a too limited and too inade
quate notion of the probable, which they have confounded with
the Endoxon 4 or the probable (opinable) of Aristotle; for Aris
totle in his " Topics" did not mean to accommodate himself to
the opinion of others, as did the orators and sophists. Endoxon
is with him what has been received from the greatest number
or the most authoritative : he is wrong in having restricted
his " Topics " to this, and this view caused him to adhere only
to received maxims, for the most part vague, as if he wished
1 Leibnitz probably refers to Tirso Gonzalez, General of the Jesuits from
1687-1705, and author of a work on probabilism, opposing the doctrine and
maintaining that the Jesuits did not originate it, entitled Fundamentum
theologize moralis, id est tractatus theologicus de recto usu opinion am proba-
bilium,^to, Dillingen, 1(589, Naples, 1694. An abridgment with the title Synop
sis tract, thcol. de recto usu opinionum probabilium, concinnata a theologo
qnodam Soc.Jesu: cui accessit loaistica probabilitatum, 3d ed., appeared at
Venice, 1696, 8vo. Cf. Michaud, Bio<j. Univ. 18, 111-112, Du Pin, Biblioth. des
ant. eccles. du XVII. sieclc, and, for the De recto nsu opin. prob., Migne, TheoL
cur. compl. Vol. 11, p. 1397.— TR.
2 The theory of moral probabilism is, perhaps the most celebi-ated question
discussed in Moral Theology, and formed one of the chief subjects of contro
versy between the Jansenists and the Jesuits of the seventeenth century.
The aim of moral probabilism is to find some rule by which action may be
determined in that portion of the moral realm in which certainty is impossible,
and probability only can be attained. The probable opinion being that which
has a certain number of arguments in its favor, either intrinsic, i.e., grounded
in reason, judgment in regard to which was restricted to men of considerable
education and especially to those versed in moral theology, or extrinsic, i.e.,
resting on some external authority, such as that of some theologian of repute ;
and the safe opinion, that which conforms to the moral law, casuists distinguish
the following doctrines : 1. Probabilism, which permits action in accord with
the opinion which is least probable and least safe ; 2. Probabilorism, or the
preference of the most probable opinion, regardless of its relative safety ;
3. Tutiorism, or the choice of the safest opinion, without regard to its rela
tive probability. On the whole subject, cf. the dissertation of Pierre Nicole
annexed to his Latin trans, of Pascal's Lcttres pror/nciales, and Janet, La
Morale, Bk. III., Chap. 3, Paris, 1874, Eng. trans., The Theory of Morals, pp.
292-308, New York, Chas. Scribner's Sons, 1883. — TR.
3 According to Janet, the casuists refuted by Pascal. — TR.
O,/. Topics, I., 1, 100" 21 : eV5o£a 6e TO. SOKOVVTO. •na.ai.v >) rot? TrAeiVrots 77 TOI? cro^>ot?,
Kol TOUTOts ri naffiv Y) rots TrAeurroi? 77 rot? ^aAtcrTa •yi'wpt'/xoi? Kal ei/S6£o(.s. — TR.
en. n] ON HUMAN UNDERSTANDING 419
to reason only by means of quodlibets l or proverbs. But the
probable or the likely is more extended : it must be drawn
from the nature of things ; and the opinion of persons whose
authority has weight is one of the things which may contribute
to render an opinion probable, but not what completes the en
tire verisimilitude. At the time when Copernicus 2 was almost
alone in his opinion, it was still incomparably more probable
than that of all the rest of the human race. Now T do not know
but that the establishment of the art of estimating probabilities*
would be more useful than a majority of our demonstrative
sciences, and I have thought of this more than once.]
Ph. Sensitive knowledge, or that which establishes the exist
ence of particular beings without us, goes beyond bare proba
bility ; but it has not all the certainty of the two degrees of
knowledge of which we have just spoken. Nothing is more
certain than that the idea we receive of an external object is
in our mind, and this is intuitive knowledge : but the knowl
edge whether from this we can certainly infer the existence
of anything without us corresponding to this idea, this it is
which certain persons think may be questioned, because men
may have such ideas in their minds, when no such thing actu
ally exists. For myself I believe, however, that there is a
degree of evidence which elevates us beyond doubt. One is
unalterably convinced that there is a great difference between
the perceptions which he has when by day he looks at the sun,
and when by night he thinks about it ; and the idea which is
1 The Mediaeval Latin " quodlibetum " was a very elaborate and subtle
scholastic argumentation upon a question chosen at pleasure — " quod libet "
— but almost always of a theological or philosophical character. Such ques
tions were called " quodlibetariae qusestiones " ; they were proposed chiefly
for the exercise of students, and their discussion was carried on to satisfy
curiosity or for entertainment, and, for the most part, served rather to exhibit
the skill and dexterity of the dialectician than to establish truth. The French
word "quolibet," starting from the scholastic use of the term in the sense of
an argumentative subtlety, came by a debasing extension of this meaning to
signify a witty, but not always appropriate commonplace, a bad joke, a pun,
an epigram ; and it is in this sense that Leibnitz, coupling the word with
" proverbs," uses the term. — TR.
2 Nicolas Copernicus, 1473-1543, published his theory of the planetary system
in his De orbium cwlestium revolutionibus lit. VI., Nuremberg, 1543, 2d ed.,
Basle, 1566, both fol. 3d ed., with notes by Nicolas Muler in his Astronomia
Instaurata, Amsterdam, 1617 and 1640, 4to. — TR.
3 Cf. ante, p. 213, note 2, p. 214, note 1 ; also Erdmann, Leibnit. opera
philos., 84. — TR.
420 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
renewed by recourse to the memory is very different from that
which actually comes to us by means of the senses. Some one
will say that a dream may produce the same effect. I reply
in the first place that it matters little that I remove this doubt,
because if all is but a dream, reasoning is useless, truth and
knowledge nothing at all. In the second place, he will ac
knowledge, in my opinion, the difference between dreaming of
being in a tire, and being actually in it. And if he persists in
appearing sceptical, I shall tell him that it is enough that we
certainly find pleasure or pain following the application to
ourselves of certain objects, true or dreamt of, and that this
certitude is as great as our happiness or misery ; two things
beyond which we have no interest. Thus I think we may count
three sorts of knowledge : intuitive, demonstrative and sensitive.
Th. [I think you are right, sir, and I also think that to
these species of certitude or certain knowledge you can add the
knowledge of the probable; thus there will be two sorts of
knowledge, as there are two sorts of proofs, the first of which
produce certitude, and the second end only in probability. But
let us come to this dispute of the Sceptics and the Dogmatists
upon the existence of things without us. We have already
touched upon it, but we must return to it here. I formerly
discussed the subject a great deal viva voce and in writing
with the late Abbe Foucher,1 Canon of Dijon, a learned and
1 Simon Foucher, 1644-1696, a devoted student of the Platonic philosophy,
in consequence of which he was called " the restorer of the philosophy of the
Academy." His Critique de la Recherche de la Verite, here mentioned by
Leibnitz, appeared at Paris, 1675. It was based upon the sceptical principles
of the Middle Academy, and was subjected to a very sharp criticism by Male-
branche in the Preface to the next edition of the Recherche de la Verite.
Foucher also wrote Dissertation sur la recherche de la verite ou sur la philo
sophic des acade'miciens, Paris, 167o, said to be his best work, and De la
Xagesse des anciens, Paris, 1683. For Foucher's "objections" (published in
the "Journal des Savans " of Sept. 12, 161)5) to Leibnitz's doctrine of pre-
established harmony as set forth in the ISyxteme noaveaa ("Jour, des Savans,"
June 27, 1695), c/. Gerhardt, 1,424, and 4, 487, Erdmann, 129, Dutens, 2, Pt. I.,
102, trans. Duncan, 81; and for Leibnitz's reply ("Jour, des Savans," April 2
and 9, 1696), c/. G. 4, 493, E. 131, Dutens, 2, Pt. I., 67, trans. Duncan, 85. The
correspondence of Foucher with Leibnitz was first published by Foucher de
Careil in his Lettres et opuscules inedits de Leibniz, Paris, 1854, pp. 27-131 (cf.
Introd. pp. 22-41, where the controversy over Malebranche is thoroughly con
sidered), and more recently, 1875, after a new comparison with the originals
in the Royal Library at Hannover, by Gerhardt, Leibniz, philos. tichrift., 1,
363 sg. — TR.
on. n] ON HUMAN UNDERSTANDING 421
subtile man, but a little too prepossessed in favor of his Acad
emicians, which sect he was very desirous of reviving, as Gas-
sendi1 had brought upon the stage that of Epicurus.2 His
critique upon " The Search after Truth," 3 and the other minor
treatises which he afterwards published, have made their
author quite well known. He published also in the " Journal
des Savans " some objections to my System of Pre-established
Harmony, when I gave it to the public after having digested
it for many years ; but death prevented him from replying to.
my answer. He always preached the necessity of guarding
against prejudice and of using great accuracy, but besides the
fact that he himself did not make it his duty to carry out his
counsel to others, in which he was perhaps excusable, it seems
to me that he was not careful whether another did it, antici
pating doubtless that no one would ever do it. Xow I showed
him that the truth of sensible things consisted only in the
connection of phenomena, which must have its reason and is
that which distinguishes them from dreams ; but that the
1 Cf. ante, pp. 64, note 2, 05, n. 3. Gassendi published on the life and phi
losophy of Epicurus: De vita, moribus et doctrina Epicuri, Lugd. Bat., 1(547;
Animadversiones in libr. X. Dioy. Laert. de Epicuro, Lugd. Bat. 1049; Syn-
taama philos. Epicuri, The Hague, 1G55. For his philosophy, cf. his Syntagma
philosophicum, Vols. 1 and 2 of his Opera omnia ; also Stockl, Gesch. d. Phi
los. d. Mittelalters, III. [Vol. 4], 310-327; Lange, Gesch. d. Mater ialismus,
Vol. 1, Eng. trans. Vol. 1, pp. 253-209; R. Adamsou, article "Gasseudi," in
Enf-yclop. Brit., 9th ed. — TK.
2 Cf. ante, p. 120, note 1. On his life and philosophy, cf. Zeller, Philos. d.
Griech., III., 1 [Vol. 5], 303 sq., 3d ed., Leipzig, 1880; Lange, Gesch. d. Materi
alismus, Vol. 1, Eng. trans., Vol. 1, pp. 98 sq. ; Benn, The Greek Philosophers,
Vol. 2, pp. 53 sq. ; Wm. Wallace, Epicureanism, in the series of " Chief
Ancient Philosophies," pub. by the Society for promoting Christian Knowl
edge, London, 1880. — TR.
3 The De la Recherche de la Verite, the principal work of Malebranche,
1038-1715, appeared in 1074-1079. The most recent edition is that of F. Bouil-
lier, with an introduction and notes, 2 vols., Paris, 1880. On Malebranche's
philosophy, cf. Bouillier, Histoire de la Philos. Cartesienne, Paris, 1854; Olle'-
Laprnne, La Philos. de Malebranche, 2 vols., Paris, 1870-1872; Kuno Fischer,
Gesch. d. n. Philos., 3d ed., I., 1, Eng. trans, by J. P. Gordy, New York, Scrib-
ners, 1887 ; Martineau, Types of Ethical Theory, 2d ed., Vol. 1, p. 159 sq. For
a critical account of Malebranche's place in the history of philosophy, cf.
Edward Caird, article " Cartesianism," in Encyclop. Brit., 9th ed. For Leib
nitz's correspondence with Malebranche, cf. Gerhardt, Leibniz, philos. tichrift.,
1, 315-3(51 ; for his discussion of Malebranche's philosophy, cf. Gerhardt, 3,
05(5-000, Erdmann, 735-737, Dutens, 2, Pt. I., 213, trans. Duncan, 233-237; G.
0, 579-594 (cf. also 481-483) , E. 090-097, D. 2, Pt. I., 201 ; G. (5, 574-578 (cf. also
480-483; Locke's examination of Malebranche is in his Philos. Works, Vol. 2,
413-458, Bonn's ed.), E. 450-452, trans. Duncan, 185-189. —TR.
422 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
truth of our existence and the cause of phenomena is of a
different nature, because it establishes substances, and that
the Sceptics spoiled what they rightly say'by carrying it too
far, and by wishing indeed to extend their doubts even to
immediate experience, and to the geometrical truths, a thing
which Foucher did not do however, and to the other truths
of reason, which he did a little too much. But to return to
you, sir, you are right in saying that there is ordinarily some
difference between feelings and imaginations ; hut the Sceptics
will say that the more or less does not alter the species. Be
sides, although feelings are wont to be more vivid than im
aginations, it is nevertheless a fact that there are cases where
imaginative persons are impressed as much or perhaps more
by their imaginations than another is by the truth of things ;
so that I think the true criterion concerning the objects of the
senses is the connection of the phenomena, i.e. the connection
of that which takes place in different places and times, and
in the experience of different men who are themselves, each to
the others, very important phenomena in this respect. And
the connection of the phenomena which guarantees the truths of
fact in respect to sensible things outside of us, is verified by
means of the truths of reason; as the phenomena of optics are
explained by geometry. It must, however, be admitted that
none of this certitude is of the highest degree, as you have
well recognized. For it is not impossible, metaphysically
speaking, that there may be a dream continuous and lasting
like the life of a man ; but it is a thing as contrary to reason
as would be the fiction of a book which should be formed by
chance by throwing together the type pell-mell. For the rest,
it is also true that, provided the phenomena are connected, it
does not matter whether they are called dreams or not, since
experience shows that we are not deceived in the measures we
take concerning phenomena when they are understood accord
ing to the truths of reason.1]
1 Cf. Neiv Essays, Bk. III., chap 4, § 2, Th., ante, pp. 318, 319, notes 1 and
2, and Bk. IV., chap. 11, § 10, Th., infra, p. 512. The principle of the "con
nection of the phenomena," their constant occurrence in the same order and
relations, giving them a certain measure of ohjectivity in our consciousness
and enabling us to predict the appearance of other members of the series when
one member presents itself, is for Leibnitz the guarantee of the truth of our
sense-knowledge and the ground of our greatest possible certainty therein ;
en. in] ON HUMAN UNDERSTANDING 423
§ 15. Ph. For the rest, knowledge is not always clear, though
ideas may be. A man who has as clear ideas as any mathe
matician in the world of the angles of a triangle and of equality
to two right angles, may yet have a very obscure perception of
their agreement.
Th. [Ordinarily when ideas are thoroughly understood their
agreements and disagreements appear. I admit, however, that
at times some of them are so complex, that much care is needed
to develop what they conceal; and in this respect certain
agreements or disagreements may still remain obscure. As
to your example, I remark that if we have in the imag
ination the angles of a triangle we do not on that account
have clear ideas of them. The imagination cannot furnish us
an image common to acute-angled and obtuse-angled triangles,
and yet the idea of triangle is common to them : thus this
idea does not consist in images and it is not as easy as you
may think thoroughly to understand the angles of a triangle.]
CHAPTER III
OF THE EXTENT OF HUMAN KNOWLEDGE
§ 1. Ph. Our knowledge does not extend beyond our ideas,
§ 2. nor beyond the perception of their agreement or dis
agreement. § 3. It cannot always be intuitive, because we
cannot always compare things immediately, for example, the
size of two triangles upon one and the same base, equal, but
very different. § 4. Our knowledge, also, cannot always be
demonstrative, for we cannot always find mediate ideas. § 5.
Finally, our sensitive knowledge regards only the existence of
things which actually strike our senses. § 6. Thus not only
our ideas are limited, but also our knowledge is more limited
than our ideas. I do not doubt however that human knowl
edge can be carried much farther if men will devote them-
but he holds that this guarantee is " verified," and the consecutions of experi
ence supplemented, "by means of the truths of reason," and particularly by
the use of the principles of logic. The position here taken is also that of the
modern scientist, who keeps strictly within the scientific realm and does not
pass on to consider the ultimate metaphysical nature and ground of the
phenomena he investigates. — TR.
424 LEIBNITZ'S CRITIQUE OF LOCKE [UK. iv
selves sincerely to discovering the means of perfecting truth,
with entire freedom of mind and with all the application and
industry they employ in coloring or maintaining falsehood, in
defending a system in favor of which they have declared
themselves, or else a certain party and certain interests, with
which they find themselves united. But after all our knowledge
can never embrace all we may wish to know concerning the
ideas we have. For example, we shall never perhaps be able
to find a circle equal to a square, and know certainly that it is so.
Th. [There are confused ideas in which we cannot promise
ourselves a complete knowledge, like those of certain sensible
qualities. But when they are distinct, there is room to hope
for all. As for the square equal to the circle, Archimedes has
already shown that there is one. For it is the one whose side
is the mean proportional between the semi-diameter and the
semi-circumference. He has also determined a straight line
equal to the circumference of the circle by means of a straight
line tangent to the spiral, as others by the tangent to the
quadratrix ; a method of quadrature with which Clavius l was
wholly content ; not to speak of a thread applied to the cir
cumference and then stretched out, or of the circumference
which revolves to describe the cycloid and is changed to a
straight line. Some demand that the construction be made
by employing only the ruler and the compasses ; but the
majority of geometrical problems cannot be constructed by
this means. The question then is rather that of finding the
proportion between the square and the circle. But this pro
portion not being capable of expression in finite rational num
bers, it has been necessary, in order to employ only rational
numbers, to express this same proportion in an infinite series 2
1 Christopher Clavius, 1537-1612, a Jesuit and distinguished mathematician,
Professor of Mathematics at Rome, and called "the Euclid of the sixteenth
century," was employed by Pope Gregory XIII. in the reformation of the
calendar, for which he made the principal calculations. Among his works
are: Euclidis elementorum, Rome, 1574; Sinux linese tan gent ex, etc., Rome,
158(5, 4to; Romani Calendar ii a Gref/orio XIII. P.M. re at it it ti Explicatio,
Rome, 1(503. His Opera mathematical, containing these and several other
works, appeared at Mayence, 1(512, 5 vols., fol. — TB.
2 Leibnitz's infinite series, which, according to Schaarschmidt, he had dis
covered before he became acquainted with Huygeus, and also before his
discovery of the infinitesimal calculus, is - = 1 — - + * — * + - - + —..., and
4: O O i 9 11 1*3
CH. in] ON HUMAN UNDERSTANDING 425
of these numbers, which I have assigned in a manner quite
simple. Now we should like to know whether there is not
some finite quantity, although it be irrational only, or more
than irrational, which can express this infinite series, that is
to say, whether we can find exactly an abbreviated expression
for this series. But finite, especially irrational, expressions, if
we proceed to the most irrational of all, may vary in too many
ways for us to be able to make an enumeration of them or to
determine easily all that they are capable of. There might be
perhaps a means of doing it if this irrationality should be ex
plained by an ordinary, or even more, an extraordinary equa-
as related to unity it expresses the proportion obtaining between the circle
and the circumscribed square. Cf. DC vera proportion* circuit ad quadratum
cii'cumscriptnm in numeris rationalibus, " Acta Erud. Lips.," February, 1682,
p. 41 sq., Gerharclt, Leibniz, math. &chrift., II., 1 [Vol. 5], 118, Dutens, Leib-
nit. op. om., 3, 140 sq.; Quadratura arithmetica, "Acta Erud. Lip.," April,
1091, p. 180, Gerhardt, Leibniz, math. Schrift., II., 1 [Vol. 5], 130, Dutens,
3, 241* ; also letter to Conring, Jan. 3, 1078, Gerhardt, Leibniz, philos. Schrift.,
1, 187.
The problem of which Leibnitz here speaks is the modern form of the prob-.
lems of the rectification and quadrature of the circle or the calculation and
construction of TT and of a square mathematically exactly equal in area to a
given circle. In referring to it he distinguishes between an "ordinary," or
algebraic, and an "extraordinary," or, as it is now termed, transcendental
equation. The problem is to prove that ir cannot be the root of any equation
having whole numbers for coefficients, or that IT is not algebraical. The quad
rature of the circle has long been known to be an unsolvable problem, — Leib
nitz knew this,— but the impossibility of its solution has only recently been
demonstrated. Not until mathematicians possessed the methods furnished by
the theory of definite integrals and the departments of higher algebra devel
oped in the last few decades was this demonstration possible. With the aid
of these methods Prof. Lindemann of Konigsberg succeeded, in June, 1882, in
demonstrating with exactness the non-algebraic character of ?r, and thus
proved for the first time that the rectification and the squaring of the circle
with ruler and compasses is impossible. For his proof, cf. L'ber die Ludolph'sche
Zahl. in the " Sitzungsberichte d. kongl. Pr. Akad. d. Wiss., zu Berlin," June
22, 1882, pp. 079-682 ; the " Comptes Rendus " of the French Academy, Vol.
lir,, pp. 72-74, " Math. Annalen," Vol. 20, pp. 213-225.
For an historical sketch of the problem of circle-quadrature, cf. Holtzen-
dorff and Virchow, Xainmluur/ gemeinverstandlicher wissenschaf flicker Vor-
trtiye. Heft 07 ; an article from this by H. Schubert, in " The Monist," January,
1891, Vol. 1, No. 2, pp. 197-228, reprinted in Smithsonian Report, 1890, pp. 97-
120; and the article " Squaring of the Circle," in the Encyclop. Brit., 9th ed.,
Vol. 22, pp. 450-454 (American Reprint). On Leibnitz's relation to the prob
lem, cf. Rummer, Festrede am Leibiiiztitf/c, in the " Monatsberichte d. Pr.
Akad. d. Wiss.," July, 1807, p. 387 *<?., an article which, while not directly
taking into consideration the present interesting passage for the history of
mathematics, is admirable in its understanding of the peculiarities of Leib
nitz's method of thought- — Tu.
426 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
tion, which would introduce the irrational or even the unknown
quantity into the exponent,1 for which, however, an extended
calculation would be required, and in which the difficulty will
not easily be solved unless we some day find a short method for
its solution. But to exclude all the finite expressions is impos
sible, as I myself know, and to determine exactly the best is
an immense task. And all this shows us that the human
mind proposes questions so strange, especially when the infinite
enters therein, that we must not be astonished if there is some
difficulty in making them out, so much the more as all depends
often on a short method in these geometrical matters, which
cannot always be determined on, just as fractions cannot
always be reduced to the lowest terms or the divisors of a
number be found. It is true that we may always have these
divisors if they are possible, because their number is finite ;
but when what we have to examine is infinitely variable and
ascends by degrees, we are not its master though we wish to
be, and it is too laborious to do all that is necessary in order
to attempt methodically to reach the short method or the rule
of progression exempting us from going farther. And as its
usefulness does not correspond to the labor, its success is left
to posterity, which will be able to enjoy it when this labor or
prolixity is diminished by the new preparations and means
which time may furnish. Unless the persons who devote
themselves from time to time to these studies determine to do
properly what is necessary in order to further progress, we
cannot hope to advance much in a short time. And we must
not think that all is done, since indeed in ordinary geometry,
we still have no method for determining the best constructions
when the problems are a little complex. A certain progres
sion of synthesis should be mixed with our analysis in order
the better to succeed. And I remember to have heard it said
that the Pensionary De Witt 2 had some thoughts on this
subject.]
1 Cf. Letter to Arnauld, Gerhardt, Leibniz, philos. Schrift., 2, 61, G2, Janet,
(Eavres phitos. de Leibniz, 1, 622. — TR.
2 John De Witt, 1625-1(572, an illustrious Dutch statesman, was a steadfast
opponent of the House of Orange, whose re-elevation to power in the United
Provinces he labored earnestly and for many years successfully to prevent.
His plans for his country were finally defeated by the diplomacy of Louis
XIV., the opposition of the Calvinist clergy, and the change in the popular
CH. in] ON HUMAN UNDERSTANDING 427
Ph. There is, indeed, another difficulty, to know whether a
purely material being thinks or not,1 and perhaps we shall never
be capable of knowing this, although we have ideas of matter
and of thought, for the reason that it is impossible for us to
discover by contemplation of our own ideas without revelation,
whether God has not given to some masses of matter, fitly dis
posed, the power to perceive and to think, or whether he has
not united and joined to matter so disposed an immaterial
substance that thinks. For as' regards our notions, it is no
more difficult for us to conceive that God, if he pleases, can
add to our idea of matter the faculty of thinking, than to under
stand that he joins to it another substance with the faculty of
thinking, since we know not wherein thinking consists, nor to
what kind of substance this all powerful Being has been
pleased to give that power, which cannot exist in any created
being save by virtue of the good pleasure and the bounty of
the Creator.
Th. [This question is without doubt incomparably more
important than the preceding ; but I venture to say to you,
sir, that I wish it were as easy to touch souls in order to
influence them for their good, and to heal bodies of their
diseases, as I think it is in our power to determine this ques
tion. T hope you will admit at least that I can advance with
out offending against modesty and without speaking as a master
in default of good reasons ; for besides speaking only accord
ing to received and common opinion, I think I have brought
thereto an attention not common. In the first place, I grant
you, sir, that when we have only confused ideas of thought and
of matter, as is ordinarily the case, we must not be astonished
if we do not see the means of solving such questions. As I
remarked a little before, one who has only the ideas of the
angles of a triangle commonly held will never think of finding
feeling towards the Prince of Orange, occasioned by the recollection of their
country's obligations to his ancestors. He was massacred, with his brother
Cornelius, in the revolution which put the Prince William (afterwards William
III. of England) at the head of the United Provinces. He published Elententa
linearuni currurum, Leyden, 1(550; The Hague, 170!). — TK.
1 Cf. (Ditc, p. 5(5 .SY/., where Leibnitz shows that Locke afterwards gave up
the opinion which he once advanced as possible that matter can think. For Leib
nitz, who regards matter as a mere phenomenon and not a reality, the question
does not exist. — TR.
428 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
them always equal to two right angles. We must consider
that matter taken as a complete being (i.e. secondary matter in
distinction from the primary, which is something purely passive
and consequently incomplete) is only a mass, or that which
results therefrom, and that every real mass supposes simple
substances or real unities, and when we further consider what
belongs to the nature of these real unities, i.e. perception and
its consequences, we are transferred so to speak into another
world, that is to say into the intelligible world of substances
while before we have been only among the phenomena of the
senses. And this knowledge of the interior of matter shows
us sufficiently its natural capability, and that whenever God
shall give it organs suitable for rational expression, the imma
terial substance which reasons will not fail to be given it also,
in virtue of that harmony which is also a natural consequence
of substances. [Matter cannot subsist without immaterial
substances, i.e. without the unities ; after which the question
should no longer be asked whether God is free to give them to
it or not ; and if these substances had not in themselves this
correspondence or harmony of which I have just spoken, God
would not act in accordance with the natural order. To speak
in an entirely simple manner of giving or according powers is
to return to the naked faculties of the schoolmen and to im
agine minute self-subsisting entities, which may go in and out
like pigeons from a pigeon-house. It is making substances of
them without being aware of it. The primitive powers con
stitute substances themselves, and the derivative powers, or. if
you prefer, the faculties, are only modes of being, which must-
be derived from substances, and are not derived from matter
so long as it is only a machine, i.e. so long as it is abstractly
'considered only as the incomplete essence of primary matter, or
passivity pure and simple. As to which I think you will
agree, sir, that it is not within the power of mere mechanism
to produce perception, sensation, reason. They must then
spring from some other substantial thing. To desire God to
act otherwise and to give to things accidents which are not
modes of being or modifications derived from substances, is to
have recourse to miracles and to what the schoolmen called the
obediential power, by a kind of supernatural exaltation, as when
certain theologians claim that. the fire of hell burns up sepa
en. in] ON HUMAN UNDERSTANDING 4*9
rated souls. In which case it may indeed be doubted whether
it was the fire that acted or whether God did not himself
produce the effect, acting in place of the fire.]
Ph. You surprise me somewhat by your elucidations, and
you anticipate me in many of the things I was going to say
to you upon the limits of our knowledge. I should have said
to you that we are not in a state of vision, as the theologians
call it, that faith and probability must suffice us as regards
many things, and particularly as regards the immateriality of
the soul; that all the great ends of morality and religion are
established upon sufficiently good foundations without the aid
of the proofs of this immateriality drawn from philosophy ;
and that it is evident that he who has begun to make us sub
sist here as sensible and intelligent beings, and who has pre
served us many years in this state, can and will make us enjoy
also a similar state of sensibility in the other life, and make
us capable of receiving there the retribution he has designed
for men according as they shall have conducted themselves in
this life ; in fine that we may judge by this that the necessity
to determine for or against the immateriality of the soul is not
so great as some people too zealous for their own views have
wished to persuade us. [I was going to say all this to you,
and more besides to the same effect, but I see now how differ
ent is the statement that we are sensible, thinking, immortal
beings by nature and the statement that we are so only by mir
acle. It is a miracle, in fact, which I know I must admit if the
soul is not immaterial ; but this view of miracle, besides being
without foundation, will not produce a sufficiently good effect in
the minds of most people. I see clearly also from the way you
understand the matter, that we can decide rationally as regards
the present question, without finding it needful to depart to
the enjoyment of the state of vision and to find ourselves in the
company of those superior spirits who penetrate very deeply
into the internal constitution of things and whose living and
penetrating sight and vast field of knowledge may make us
imagine by conjecture what happiness they must enjoy.] I
had supposed it entirely beyond our knowledge to combine sen
sation with extended matter, and existence with a thing ichich has
absolutely no extension. I had therefore become convinced that
those who took sides here followed the unreasonable method
430 LEIBNITZ'S CRITIQUE OF LOCKE [nK. TV
of certain persons, who, seeing that things considered from a
certain side are incomprehensible, throw themselves headlong
upon the opposite side, although it is no less unintelligible ; a
procedure which arose in my opinion from the fact that some
having their mind too deeply buried so to speak in matter,
could not accord any existence to that which is not material ;
and others not finding that thought is included in the natural
faculties of matter, concluded that God himself could not give
life and perception to a solid substance without putting therein
an immaterial substance ; while I now see that if He had done
so it would be by a miracle, and that this incomprehensibility
of the union of the soul and the body or of the union of sensa
tion with matter seems to cease through your hypothesis of pre-
established harmony between different substances.]
Th. [In fact there is nothing unintelligible in this new
hypothesis, since it attributes to the soul and to bodies only
the modifications which we experience in ourselves and in
them ; and only makes them appear more regular and more
connected than has been thought hitherto. The .difficulty
which remains exists only as regards those who wish to imagine
what is only intelligible,1 as if they wished to see sounds or hear
colors, and these are they who refuse existence to everything
which is net extended, a view which will compel them to refuse
it to God himself, i.e. to renounce the causes and reasons of
changes and of such changes : these reasons being incapable of
arising from extension and from natures purely passive,
and not indeed wholly from particular and inferior active
natures without the pure and universal act of the supreme
substance.]
Ph. One objection remains for me with reference to things
whose matter is naturally susceptible of feeling. The body
so far as we can conceive it, is capable only of striking and
effecting a body, and motion can produce nothing but motion :
so that when we agree that the body produces pleasure or
pain or the idea of a color or sound, we seem compelled to
abandon our reason, to go beyond our own ideas, and to at
tribute this production solely to the good pleasure of our
Creator. AVhat reason have we then to conclude that it is
not the same with perception in matter ? I almost see what
i Cf. ante, p. 274, note 2. — TR.
CH. in] ON HUMAN UNDERSTANDING 431
reply you can make, and although you have already said some
thing regarding it more than once, I understand you better
now, sir, than I have done. But I shall be very glad to hear
further what reply you will make regarding it upon this
important occasion.
Tli. [You rightly judge, sir, that I shall say that matter
cannot produce pleasure, pain, or thought in us. It is the soul
itself which produces them in conformity to what takes place
in matter. And some clever people among the moderns begin
to declare that they understand occasional causes only as I.
Xow this being posited, there occurs nothing unintelligible,
except that we cannot distinguish all that enters into our con
fused perceptions, which contain even the infinite, and which
are the detailed expression of what occurs in bodies. As for
the good pleasure of the Creator, it must be said that he is
ruled by the natures of things, so that he produces and con
serves therein only what suits them and can be explained, at
least in general, by their natures; for the detail often sur
passes us as much as the care and power of arranging the
grains of a mountain of sand according to the order of the
figures, although there is here nothing difficult to understand
but the multitude. Otherwise if this knowledge were in
itself beyond us, and if we could not indeed conceive the rea
son of the relations of the soul and body in general, in fine,
if God gave to things accidental powers detached from their
natures, and consequently removed from reason in general,
there would be a back door for calling back the too occult quali
ties which no mind can understand, and these "little goblins of
faculties incapable of reason,
Et quidquid Schola finxit otiosa:
helpful goblins who proceed to appear like the gods of the
theatre, or like the fairies of the Amadis, and who will do at need
all that a philosopher wishes, without ceremony and without
tools. But to attribute the origin of these powers to the good
pleasure of God appears to me a thing not quite congruous with
him who is the supreme reason, with whom everything is
regular, everything consistent. This good pleasure would riot
indeed be good, nor pleasure, if there were not a perpetual
parallelism between the power and the wisdom of God.]
432 LEIBNITZ'S CRITIQUE OF LOCKE [UK. iv
§ 8. Ph. Our knowledge of identity and diversity goes as far
as our ideas, but that of the connection of our ideas, §§9, 10.
as regards their coexistence in one and the same subject is
very imperfect and almost nothing § 11. especially as regards
secondary qualities as colors, sounds, and tastes § 12. because
we do not know their connection with the primary qualities,
i.e. § 13. how they depend upon size, figure, or motion. § 15.
We know a little more of the incompatibility of the secondary
qualities ; for a subject cannot have, for example, two colors
at the same time, and when they seem to be seen in an opal or
in an infusion of lignum nephriticum, it is in different parts of
the object. § 16. It is the same with the active and passive
powers of bodies. Our researches in this direction must depend
on experience.
Tli. [The ideas of sensible qualities are confused, and the
powers which should produce them furnish in consequence only
ideas into which some confusion enters : thus the connections
of these ideas can be known otherwise than by experience
only as they are reduced to the distinct ideas which accom
pany them, as has been done (for example) in regard to the
colors of the rainbow and of prisms. And this method pre
sents a beginning in analysis which is of great use in physics ;
and by following it I doubt not that medicine in time will
find itself considerably more advanced, especially if the public
is a little better interested than hitherto.]
§ 18. Ph. As for the knowledge of relations it is the largest
field of our knowledge and it is difficult to determine how far
it may extend. Progress depends on our sagacity in finding
intermediate ideas. Those who are ignorant of algebra cannot
imagine the wonderful things that may be done in this field
by means of this science. And I do not see that it is easy to
determine what new means of perfecting other parts of our
knowledge may yet be found out by a penetrating mind. At
least the ideas regarding quantity are not the only ones capable
of demonstration ; there are others, perhaps the most important
part of our contemplation, from which we might deduce certain
knowledge, if vices, passions, and domineering did not directly
oppose the execution of such enterprise.
Tli. [Nothing is truer than what you, sir, here say. What
is there more important, supposing it is true, than what I be-
CH. in] ON HUMAN UNDERSTANDING 433
lieve we have determined upon the nature of substance, upon
unity and multiplicity, upon identity and diversity, upon the
constitution of individuals, upon the impossibilities of void
and atoms, upon the origin of cohesion, upon the law of con
tinuity, and the other laws of nature ; but chiefly upon the
harmony of things, the immateriality of souls, the union of
the soul and the body, the conservation of souls, and even of
the animal after death. And there is nothing in all this which
I do not think demonstrated or demonstrable.]
Ph. [It is true that your hypothesis appears extremely con
sistent and of great simplicity : a clever man in France who
desired to refute it, admits publicly that he was impressed by
it. And it is a simplicity very different from that which I see.
It will be well to show this doctrine more and more in its true
light. But in speaking of things which are of most importance
to w,s, I thought of morality to which I admit your metaphysic
gives wonderful foundations : but without digging so deep, it
has sufficiently firm foundations, although perhaps they do not
extend as far (as I remember that you remarked) when a nat
ural theology like yours is not their base. Yet the considera
tion of the goods of this life alone already serves to establish
important consequences for regulating human society. We
can estimate justice and injustice as incontestably as in math
ematics ; for example this proposition : There cannot be injustice
where there is no property, is as certain as any demonstration
which is in Euclid ; property being the right to a certain thing,
and injustice the violation of a right. It is the same with this
proposition: 2Jo government allows absolute liberty. For gov
ernment is the establishment of certain laws, whose execution
it demands, and absolute liberty is the power each one has of
doing whatever he pleases.
Tli. [You use the word property a little differently from its
ordinary use, for you mean by it the right of one person to a
thing to the exclusion of the right of another. Thus. if there
were no property, as if all were common, there nevertheless
might be injustice. By thing in the definition of property you
must also further understand action ; for otherwise, if tli'-M'e
were therein no right to things, it would be always an injustice
to prevent men from acting where they find it needful. But
according to this explanation it is impossible that there be no
2 F
434 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
property. As for the proposition concerning the incompati
bility of government with absolute liberty, it belongs to the
number of the corollaries, i.e. the propositions, which it is
sufficient to point out. There are some in jurisprudence which
are more complex, as for example, those concerning what is
called jus accrescendi,1 concerning the conditions and many
other matters ; and I indicated them when I published in
my youth some theses upon the conditions, in which I demon
strated some of them. And if I had leisure, I would retouch
them.2]
Ph. [That would afford pleasure to the curious, and serve
to anticipate any one who might reprint them without re
vision.]
Th. [That is what happened to my " Ars Combinatoria," 8 as
I have already complained. It was a fruit of my early youth,
and yet it was reprinted a long time after without consulting
ine and without indicating even that it was a second edition,
•and this made some think to my prejudice that I was capable
1 Of. Poste, Gains, Elements of Roman Law, Bk. II., 109 (p. 202, 3d ed.,
Oxford, 1890) : " Illud constat si duolws pluribusve per viudicationem eadem
res legata sit, sive conjunctim, sive disjunctim, si omnes veniant ad legatum,
partes ad singulos pertinere, et deficientis portionem collegatario adcrescere."
Also Sandars, Inst. of Justinian, Lib. II., Tit. XX., 8 (p. 22(5, 8th ed., London,
1888): "Si eadem res duobus legata sit, sive conjunctim sive disjunctim: si
ambo perveniaut ad legatum, scinditur inter eos legatum ; si alter deficiat,
quia aut spreverit legatum, aut vivo testatore decesserit, vel alio quolibet
rnodo defecerit, totum ad collegatarium pertinet."
In reference to the jus accrescendi — the law of increase — Sandars says,
p. 15)8: " If any one instituted heir died before the testator, or refused to take
his share of the inheritance, his share was, in fact, undisposed of. But as the
testator was always supposed to have disposed of his whole estate, if he dis
posed of any part, this share was divided among all those who entered on the
inheritance in proportions corresponding to the share given them by the will.
Their claim was called the 'jus accrescendi.' " — TR.
2 Leibnitz here refers to his thesis De conditionibus, which he defended
under the presidency of Prof. Leonhard Schwendendorfer, at Leipzig, in .l(5<x>.
Guhrauer states (cf. Leibniz, eine Bionraphie, Pt. I., pp. 3(5-37) that we do
not know the treatise in its original form, but in the revision and rearrange
ment of its material made by Leibnitz in 1672, in a collection of his juristic
treatises under the title Specimina juris, and which is found in Dutens, Leilj-
nit. op. om., 4, Pt, III., 92 sq. — Tn.
3 The Dissertatio de Arte Combinatoria, cf. Gerhardt, 4, 27 sq., Erdmann,
6 ,SY/., Dutens, 2, Pt. I., 341 sq., appeared at Leipzig in 1(5(5(5. The pirated edi
tion here referred to by Leibnitz was published at Frankfort, 1(590, and re
viewed by him in the " Acta Erud.," February, 1(591. Cf. Guhrauer, Leibniz.
eine Bio</., Pt. I., pp. 37-38, and Anmerkungen z. erst. Buche, pp. 7, 8;
Dutens, 6, 295. — TR.
CH. in] ON HUMAN UNDERSTANDING 435
of publishing such a piece in my mature years ; for although
it contains thoughts of some consequence, which I still ap
prove, it also contains some which could become only a young
student.]
§ 19. Ph. I find that diagrams are a great remedy for the
uncertainty of words, but they cannot have place in moral
ideas. Most moral ideas are more complex than the diagrams
ordinarily considered in mathematics ; thus the mind finds it
difficult to retain the precise combinations of what enters into
moral ideas, in a manner as perfect as is necessary in long de
ductions. And if in arithmetic the different stages are not
designated by marks whose precise meaning is known, and
which last and remain in sight, it is well-nigh impossible to
make extended computations. § 20. Definitions furnish some
remedy provided they are constantly employed in ethics. And
for the rest, it is not easy to foresee what methods may be
suggested by algebra or by some other means of this nature to
remove other difficulties.
Tli. [The late Erhard Weigel,1 a mathematician of Jena in
Thuringia, ingeniously invented diagrams to represent moral
things ; and when the late Samuel Puffendorf,2 his disciple, pub-
1 Erhard Weigel, 1025-1699, a distinguished German mathematician and
astronomer, was professor of mathematics in Jena from 1653 on, where he was
Leibnitz's first teacher in the subject, when he studied there in 1663, cf.
Guhrauer Leibniz, erne Biographic, Pt. I., pp. 2(5, 32. The Diet of Ratisbon
appointed him to organize a commission for the correction of the calendar.
He also labored earnestly for the reform of the school system in Germany,
travelling through the country in 1696 for this purpose, cf. Guhrauer, op. cit.,
Ft. II., pp. 211-214, and the correspondence of Leibnitz and Placcius, from
Feb. 12, 1696 on, Dutens, Leibnit. op. om., 6, 61 sq.
AVeigel, who was a philosopher, moralist, and an original investigator of
the law of nature (Naturrecht) as well as a mathematician, published many
works, among them the Expose arithmetique de la morale, or, as the German
title runs, Arithmetische Beschreibung der Moralweisheit von Personen und
Sachcn, ivoraus das f/emeine We sen besteht, nach der pythagorischen Kreutz-
zahl in lauter tetraktische Glieder einyetheilt, Jena, 1674, 4to, in which he
attempted a mathematical exposition of moral philosophy, based upon the
Pythagorean principle that the essence of things consists in numbers. Leibnitz
thus speaks of this book in the Miscellanea, No. CLIII., Dutens, 6, 325: " M.
Wei<jclius a fait un excellent livre en Allemand sur la morale cclairee par
les nombres, et je ne crois pas que les Pythagoriciens ayent rien dit de plus
b»au sur ce chapitre." For further remarks of Leibnitz on Weigel, cf.
Guhrauer, Leibnitz's deutsche Schriften, 2, 473 sq. — Tit.
- Samuel Pufendorf, 1632-1694, was one of the greatest German publicists
and historians, and one of the founders of the science of public law. He
studied at Jena under Weigel, with whom he formed an intimate friendship,
436 LEIBNITZ'S CRITIQUE OF LOCKE [UK. iv
lished his " Elements of universal Jurisprudence " sufficiently
conformed to the thoughts of Weigel, there was added thereto
in the Jena edition the " Moral Sphere "of this mathematician.
But these diagrams are a kind of allegory nearly like the table
of Cebes,1 but less popular and serving the memory in the re
tention and arrangement of its ideas rather than the judgment
in the acquisition of demonstrative knowledge. They do not
cease to have their use in arousing the mind. Geometrical
diagrams appear simpler than moral things ; but they are not
so, because continuity includes the infinite from which it must
be chosen. For example, to cut a triangle into four equal
parts by two straight lines perpendicular to each other is a
question apparently simple but really quite difficult. It is not
the same in questions of morality since they are deternnnable
and to whose teaching and influence he largely owes the orderly method and
mathematical precision and dry ness which characterize his style, and that
independence of character which never yielded to the " ipsedixitism " of other
writers, however high their position and authority. Among his works are:
Elementa jurisprudent ise universalis, cum append ice de ^phxra morali (of
Weigel), Hag. Com., 1660, 12mo — also Jena, KiliO, " bei Meyer"; the ed. here
meant by Leibnitz, according to Schaarschmidt, who states that in the 2d
Jena ed., 1669, the Xphsera moralis occurs, p. 313 sq., — the book which obtained
for him from the elector Charles Louis, to whom it was dedicated, the newly
created chair of the law of nature and of nations at Heidelberg; I)e xtatn
imperil rjermairici, Geneva, 1667, — the book which first called forth Leibnitz's
aversion and criticism, — small in bulk, but great in significance, in which lie
criticised the political organization of the empire, suggested a remedy for the
evils therein, and revealed himself as a consummate statesman, subsequent
events proving the justness of his conclusions; and the work on which his
fame chiefly rests, l)e jure naturae, et f/entium, 1672, trans, into French, with
notes, by Barbeyrac, Amsterdam, 1712, and into English by Basil Kennett,
London, 1729, and resume of the same. De ojftcio hominis et cicis, 1675.
For Leibnitz's criticism of Pufendorf and his work, — the severest, perhaps,
he ever made on any one. and through which he is, to a considerable extent,
responsible for the failure of posterity justly to estimate and acknowledge
its debt to him, — rf. letter to Kestner, No. 7, § 2, Dutens, 4, Pt. III., 2*51;
Monitct qusedain ad ,v. Pujf'endorfti prindpin, 'ibid.. 275-283; letter to S. Ror-
tholt, No. 3, Dutens, 5, 305; letters to Bierling, (-Jerliardt. Leibniz. }>'lnh>s.
Sr/trift., 7, 487, 48S, 490, 499, 506, 511, Dutens, 5, 355, 358, 361, 371, 3X6. 3!)0 —
Dutens gives Bierling's letters to Leibnitz also; letter to iJourgnet. (4. 3. 590,
Erdmann, 734, !>., Dutens, 2, Pt. I., 334. For a comparison of the views of
Leibnitz and Pufendorf on the ultimate foundations of natural and publi;- law.
cf. Monita quxdain above cited, and Guhrauer, Leibniz, cine Bint/., Pt. I.. 22.".
sq. — TR.
1 Cebes of Thebes, a disciple of Socrates, distinguished for his virtue ami
love of truth; cf. Plato, Pfurdo, 59 0. 60 C .«»;/., 63 A. His inw£, Tobijla.
or ' picture,' is, according to Zeller, Philos. d. Griech., II., 1 [Vol. 3], 242, 4th
ed., 1889, " certainly spurious.'' — Tn.
CH. in] ON HUMAN UNDERSTANDING 437
by reason alone. For the rest it is not the place here to speak
de proferendis scientiae demonstrandi pomoeriis, and to propose
true means of extending the art of demonstration beyond its
ancient boundaries which have been nearly the same up to the
present time as those of mathematics. If God gives me the
time necessary for it, I hope some day to publish an essay
upon this subject, putting these means into effective use with
out limiting myself to precepts.] 1
Ph. [If you carry out this plan, sir, and as it should be,
you will infinitely oblige the Pliilalethes like myself, i.e. the class
who sincerely desire to know the truth.] For truth is naturally
agreeable to the mind, and there is nothing so deformed and
so incompatible with the understanding as a lie. But men
must not be expected to apply themselves much to these
discoveries, so long as the desire and the esteem of riches or
of power shall lead them to espouse opinions authorized by
fashion, and to seek in consequence arguments either to make
them pass as good or to varnish over and cover their deform
ity. And while the different parties make all men whom they
can get into their power receive their opinions without exam
ining whether they are true or false, what new light can be
hoped for in the sciences belonging to morals ? This part of
the human race which is under the yoke, ought to expect in
most places in the world instead of that light, darkness as
thick as that of Egypt, were not the candle of the Lord itself
found present in the mind of men,2 a sacred light which all
human power cannot wholly extinguish.
Th. [I do not despair that at some time and in a more tran
quil country men will betake themselves more to reason than
they have done. For in fact we must despair of nothing; and
1 Leibnitz's plan to extend and perfect the science of demonstration, or that
part of logic; which is concerned with the methods of proof, and which in his
view was conceived up to his own time too narrowly as virtually identical
with the method of mathematics, is closely connected, but not identical, with
bis Universal Characteristic: cf. <nitc. pp. 292, note 1, .''75, note 1. Leibnitz,
however, never carried his plan into execution, but left some preliminary
essays or sketches which serve to indicate what he thought desirable in this
direction, and what lie purposed himself some day to provide. Cf. Prec.eptes
)><>ur in-Kin'i'/' h'x Hfi<-)ic<js, Erdmann, Lcibiiit. op. jtli.ilox. KiH-lTl, published in
a more complete form in Gerhardt, Leibniz, philos. S<-1trift., 7, 157 xq. ; and
the fragment without title treating of the means of philosophical demonstra
tion, G. , 7, 299-301. — TR. * Cf. Proverbs 20 : 27. — TR.
438 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
I believe that great changes for evil and for good are reserved
for the human race, but in the end more for good than for
evil. Suppose we see some day a great prince, who, like the
ancient kings of Assyria or of Egypt or like another Solomon,
reigns a long time in a profound peace, and that this prince,
loving virtue and truth and endowed with a great and solid
mind, takes it into his head to make men happier and more
accommodating among themselves and more powerful over
nature ; what wonders will he not do in a few years ? For it
is certain that in this case more would be done in ten years
than in a hundred or perhaps a thousand while letting things
follow their ordinary course. Moreover, if the path were
opened once for all, many people would enter therein as
the geometers do, though this would be only for their pleas
ure and to acquire fame. The public better civilized will
some day turn more than it has hitherto done to the advance
ment of medicine ; natural histories of all countries will be
published like almanacs or like the Mercures gahtns;1 no val
uable observation wrill be left without being registered ; those
who will apply themselves thereto will be aided ; the art of
making such observations will be perfected, and further that
of employing them to establish aphorisms. The time will
come when the number of good physicians having become
greater and the number of people of certain professions of
which there will then be less need having become proportion
ally less, the public will be in a condition to give more
encouragement to natural research, and above all to the ad
vance of medicine, and then this important science will be
carried far beyond its present condition and will grow apace.
I believe indeed that this business of the police should be
the object of the greatest care of those who govern, after that
of virtue, and that one of the greatest fruits of good morals
or politics will be to produce a better (science of) medicine,
1 "Mercure galant," the title of different periodicals treating of politics,
literature, and containing announcements, and news of various kinds; in par
ticular, the title of a journal founded by De Vise in KJ72, and continued, with
several short periods of suspension, under various names and editors, till 1S53.
Leibnitz, in a letter to Sebastian KorthoU, Jan. 9, 1711, inquires whether a
complete set can be obtained, and at what price: " Discere etiam velim, an
totus MercuriuK Gallant, nt sic dicam, vulgo Mercure Galant a Derisse-o nuper
extincto a multis annis compositus, tolerabili pretio haberi possit, et quanti? "
O/. Dutens, Leibnit. op. om. 5, ol,r>). — TR.
CH. in] ON HUMAN UNDERSTANDING 439
when men shall begin to be wiser than they are and the no
bility shall learn the better to employ their wealth and their
power for their own welfare.]
§ 21. Ph. As for the knowledge of real existence (which is
the fourth kind of knowledge} it must be said that we have an
intuitive knowledge of our existence, a demonstrative knowledge
of that of God, and a sensitive knowledge of other things. We
shall speak of these fully in what follows.
Th. [You could say nothing more justly.]
§ 22. Ph. Having now spoken of knoicledge, it appears ap
propriate the better to discover the present condition of our
mind that we should consider a little the dark side and take
knowledge of our ignorance : for it is infinitely greater than
our knowledge. The causes of this ignorance are as follows :
(1) Want of ideas; (2) Inability to discover the connection
between the ideas we have ; (3) Neglect to trace and examine
them with exactness. § 23. As for the want of ideas, we have
as simple ideas only those coming to us from the senses [in
ternal or external]. Thus as regards an infinite number of
the creatures of the universe arid their qualities we are like
the blind as regards colors not indeed possessing the faculties
necessary in order to their knowledge ; and according to all
appearances man holds the lowest rank among intellectual
beings.
Th. [I do not know but that there are also some below us.
Why should we degrade ourselves unnecessarily? Perhaps we
hold a sufficiently honorable rank among rational animals ;
for superior genii may have bodies of another kind so that
the name animal cannot agree with them. We cannot say
whether our sun among the great number of other suns has
more above than below it, and we are well placed in his sys
tem : for the earth occupies the middle course between the
planets, and its distance appears well chosen for a contem
plative animal who should inhabit it. Besides we have in
comparably more reason to praise than to complain of our lot,
the majority of our evils rightly being imputed to o.ur fault.
Above till we should be very wrong to complain of the defects
of our knowledge, since we avail ourselves so little of that
which charitable nature presents to us.]
§ 24. Ph. It is, however, true- that the extreme distance of
440 LEIBNITZ'S CRITIQUE OF LOCKE [BK. IT
nearly all parts of the world which are exposed to our sight
conceals them from our knowledge, and apparently the visible
world is only a small part of this immense universe. We are
confined in a small corner of space, i.e. in the system of our
sun, and yet we do not know even what takes place in the
other planets which as well as our ball revolve about it.
§25. This knowledge escapes us by reason of size and dis
tance ; but other bodies are concealed from us because of their
minuteness ; and these are the ones which it would most con
cern us to know ; for from their contexture we could infer the
use and operation of those which are visible, and know why
rhubarb purges, hemlock kills, and opium produces sleep.
Thus § 26. whatever distance human industry may advance
experimental philosophy upon physical things, I am compelled
to believe that we can attain upon these matters a scientific
knowledge.
Tli. [I fully believe that we shall never advance so far as
will be desirable ; but it seems to me that some considerable
progress will be made in time in the explication of certain
phenomena, because the large number of experiments which
we are led to make may furnish us data more than sufficient,
so that only the art of employing them will be lacking, (an
art) the small beginnings of which I do not despair of seeing
pushed forward, since the infinitesimal analysis1 has given us
the means of uniting geometry with physics, and dynamics has
furnished us with the general laws of nature.]
§ 27. Ph. Spirits are still further removed from our knowl
edge ; we cannot form any idea of their different orders, and
yet the intellectual v:orld is certainly grander and more beau
tiful than the material world.
Th. [These worlds are always perfectly parallel as regards
efficient causes, but not as regards final. For in proportion as
spirits rule in matter they produce therein wonderful arrange
ments. This appears in the changes men have made, in order
to embellish the earth, as little gods imitating the great archi
tect of the universe, though only by employing bodies and
1 Sir Isaac Xewton, H 42-1727,- in his Principia, was the first to apply in a
systematic way the infinitesimal calculus to physics, after that Galileo," 15(4-
1G42, had paved the way for a theory of universal gravitation hy his deter
mination of the law of acceleration in falling bodies. — TR.
CH. m] ON HUMAN UNDERSTANDING 441
their laws. What may not be conjectured concerning this
immense multitude of spirits which surpass us? And as
spirits form all together a kind of state under God, whose gov
ernment is perfect, we are far removed from comprehending
the system of this intelligible world and from conceiving the
punishments and rewards prepared for those who deserve
them according to the most exact standard, and from imagin
ing what eye has not seen, nor ear heard, nor has ever entered
into the heart of man. But all this shows that we have all
the distinct ideas necessary for knowing bodies and spirits,
but not sufficient detail of facts, nor senses penetrating enough
to distinguish confused ideas or sufficiently extended to per
ceive them all.]
§ 28. Ph. As for the connection, the knowledge of which
is wanting to us in the ideas which we have, 1 was going to
say to you that the mechanical affections of bodies have no
connection with the ideas of colors, sounds, smells, tastes,
pleasure, and pain; and that their connection depends only
upon the good pleasure and the arbitrary will of God. But I
remember that you think there is a perfect correspondence,
although this is not always an entire resemblance. But you
recognize that the too great detail of small things entering
therein hinders us from discerning that which is concealed,
though you hope still that we shall make much advance there
in ; and that thus you do not wish to say with my illustrious
author (§ 29), that it is labor lost to engage in suck a search, from
fear that this belief would injure the growth of science. I
should have spoken also of the difficulty which has hitherto
been found in explaining the connection between the soul and
the body, since a thought cannot be conceived as producing a
motion in the body, nor a motion as producing a thought in
the mind. [But since I comprehend your hypothesis of pre-
established harmony, this difficulty of which they despaired
appears to me removed at once, and as it were, by magic.]
§ 30. There remains then the third cause of our ignorance,
viz. that we do not follow the ideas we have or may have,
and do not apply ourselves to finding intermediate ideas.
Thus it is that we are ignorant of mathematical truths, al
though there is no imperfection in our faculties, nor any
incertitude in the things themselves. The bad use of words
442 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
has contributed the most to prevent us from finding the agree
ment or disagreement of ideas; and the mathematicians who
form their thoughts independently of names and accustom
themselves to present to their minds the ideas themselves in
stead of their sounds, have thereby escaped a great deal of
embarrassment. If men had acted in their discoveries in the
material world as they have been wont to do in regard to
those having reference to the intellectual world, and if they
had been, wholly lost in a chaos of terms of an uncertain mean
ing, they would have disputed endlessly about the zones, the
tides, the building of vessels, and the routes; they would
never have gone beyond the line, and the antipodes would
still be as unknown as they were when to maintain them was
declared a heresy.
Tli. [This third cause of our ignorance is the only blamable
one; and you see, sir, that the despair of further advance is
therein contained. This discouragement does much injury;
and persons of ability and importance have hindered the
progress of medicine by the false persuasion that it is labor
lost to work therein. When you see the Aristotelian philoso
phers of past time speak of meteors, as the rainbow, for
example, you will find that they believed they should not
think alone of explaining distinctly this phenomenon ; and the
attempts of Maurolycus, l and afterwards of Marc Antony de
Dominis 2 appeared to them like the flight of Icarus. But the
1 Francesco Maurolico, 1494-1575, a celebrated Italian mathematician,
whose father, a Greek, came originally from Constantinople, taught mathe
matics at Palermo, Naples, Rome, and Messina. In his Treatise on Conies he
sought for the first time to deduce the properties of these curves from the
corresponding curves in the circle of which they are the perspective. He first
introduced secants into trigonometrical calculations, constructing and publish
ing a table of them in his Theodosii sphsericorum , Messina, 1558, fol. He also
investigated the structure of the eye, seeking therein the explanation of the
phenomena of vision. He described exactly the course of the rays of light
across the cornea and the crystalline lens, but stopped in utter astonishment
when he discovered that his theory led him to admit that the images of objects
upon the retina are found inverted. The work of Manrolico, here referred to by
Leibnitz, is his Problemata ad perspectiram et iridem pertinentia, appended
to his Photismi [or Theoremata] de lumine et umbra adperspectivamradioruni
incidentiicm, Venice, 1575, 4to, new ed., with notes of Clavius, Lyons, 1613. — TR.
2 M. Ant. de Dominis, 15P>6-lfi24, a native of Dalmatia, was professor of
eloquence, philosophy, and natural sciences at the University of Padua.
Though archbishop of Spalatro, he was republican in his views of the consti
tution and administration of the church and strongly opposed to the doctrine
CH. in] ON HUMAN UNDERSTANDING 443
sequel has disabused the world of this. It is true that the
bad use of terms has caused a good part of the confusion
found in our knowledge, not only in ethics and metaphysics,
or in what is called the intellectual world, but also in medi
cine where this abuse of terms increases more and more. We
cannot always aid ourselves with figures as in geometry : but
algebra shows us that great discoveries may be made without
recurring always to the ideas themselves of things. In ref
erence to the pretended heresy about the antipodes I will say
in passing that it is true that Boniface,1 Archbishop of May-
ence, accused Virgil of Salzburg,2 in a letter, which he wrote
of papal supremacy. "While in England he published his views in his De
republica ecclesiastica, London, 1017-1620, reprinted Frankfort, 1(558, both eds.,
3 vols., fol. For some specimen quotations from this book, cf. Larousse,
Grande Diet. Unir. de XIXe Siecle, Vol. 6, p. 1068, a. Returning to Italy, he
and his book were condemned as heretical, in spite of his retraction of his
errors, and he was imprisoned, and probably poisoned, in the Castle of St.
Angelo, and his body exhumed and burned with great ceremony in the Campo
de' Fiori in Rome in January, 1625.
In his De radiis risus et lucis in vitris perspectivis et iride, Venice, 1611,
4to, cited with high praise by Newton in his Optics, he presented to the world
the rirst attempt at a theory of the rainbow. He successfully reflected rays
of light through the interior of raindrops before making them come out again,
but could not account for the angle at which the observer sees the ray of the
bow. On his theory, cf. Venturi, Commentarii sopra la storia e le teorie dell'
ottica, Bologna, 1814, Vol. 1, p. 149. Of the De radiis visus et lucis, chap. 9
and chap. 1.3, " Vera iridis tota yeneratio evplicatur," are printed in Libri,
Histoire des Sciences math, en Italic depuis la Renaissance jusqu'a la Jin du
XVIfr siecle, 1838-1841, 4 vols., 8vo, Vol. 4, p. 436 sq. Leibnitz thus speaks
of him in the Miscellanea Leibnitiana, ed. Feller, No. CXV., p. 198 (cf. also
Dutens, Leibnit. op. om., 6, 319): " Elegantissime materiam tractavit de-
monstrationibusque mathematicis confirmavit. Iridis etiam et nonnullorum
aliorum ejusmodi meteorum causam ab Aristotele assignatam recte ex-
pendit." — TR.
1 Boniface (Winfrid, the Anglo-Saxon Benedictine monk, named Bonifa-
cius by Pope Gregory II.), 680-755, the apostle to the Germans, became arch
bishop of Mayence (Mainz) in 748. On his life and labors, cf. Neander, Hist.
of the Christ. Relig. and Church, 3, 46 sq.; Smith and Wace, Diet, of Christ.
Biog., Vol. 1, p. 324. His Opera qtoe extant omnia, ed. J. A. Giles, Londini,
1844, 2 vols., 8vo; also in Migne, Patrol, s. Lat., Vol. 89, Paris, 1863. His
letters were edited, with notes, by the Jesuit Nic. Serarius, 1555-1609, Mayence,
1605 and 1629, 4to; and by Wiirdtwein, Moguntiae, 1789, fol. — TR.
2 St. Fergil, best known by the Latinized form of his name, — Virgilius, —
was an Irish priest from Aghavoe, Queen's Co., who came to Bavaria, became
at first abbot of St. Peter's monastery in Salzburg, and finally, on the martyr
dom of Boniface, 755, and the death of John, bishop of Salzburg, was appointed
and consecrated bishop, June 13, 766 or 767. One of his last acts as bishop was
to visit his entire diocese and to pay a long deferred visit to Carinthia. He
died Nov. 27, 789.
444 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
to the Pope against him on this subject, and that the Pope
replied thereto in a way which showed that he employed the
term quite in the sense of Boniface; but it does not appear
that this accusation has had any results. Virgil has always
held his own. The two antagonists pass for saints, and the
savants of Bavaria who regard Virgil as an apostle of Carin-
thia and the neighboring countries, have justified their mem
ory of him.]
CHAPTER IV
OF THE REALITY OF OUR KNOWLEDGE
§ 1. Ph. Some one who has not understood the importance
of having good ideas, and of understanding their agreement
or disagreement, will think that in reasoning upon them so
carefully we have been building castles in the air, and that there
will be in our entire system only the ideal and imaginary. An
extravagant man, whose imagination is heated, will have the
advantage of possessing ideas more vivid and in greater num
ber, thus he would also have more knowledge. There will be
as much certitude in the visions of an enthusiast as in the
Virgil was involved in two controversies with Boniface. First, in regard to
the validity of an informally administered baptism in which the officiating
and ignorant priest had mutilated the Latin formula. Boniface said the bap
tism was invalid, and must be repeated; Virgil maintained its validity, and
on his appeal to Pope Zachary (741-752), was sustained. Second, in regard to
the "antipodes" here mentioned. Virgil published a philosophical treatise
maintaining the rotundity of the earth and the antipodes, which Boniface
regarded as heretical because the view advanced was thought to imply the
existence of two races of men, one of which did not spring from Adam, was
therefore free from original sin, and had no need for or share in the work of
the Redeemer. Pope Zachary, in the letter to Boniface here referred to (<-f.
letters of Boniface, No. 140, in Uibl. Majr. Vet. Patr., 11 vols., fol. Lugd., 1677,
Vol. 13, p. 131-133), characterized as perverse and heretical the doctrine of
another world and other men under the earth, — " De perversa doctrina, quam
contra Dominum et animam suam locutus est (quod scilicet alius mundus,
et alii homines sub terra sint aliusque sol et luna)," etc. ; but Virgil showed
that his speculations were purely scientific and did not touch the theological
doctrines of original sin or the unity of the human race. He was accordingly
acquitted of the charge of heresy, and canonized by Gregory IX. in 1233. 67'.
Smith and Wace, Diet, of Christian Biof/., Vol. 4, pp. 1160, 1211, London,
1887; Neander, Hist, of the Christ. Reli;/.and Church, 3, 63; also Bayle, Diet,
histor. et crit., 2d ed., 1702 (which was, perhaps, Leibnitz's source of infor
mation on the subject), Eng. Trans., London, 1738, Vol. 5, p. 493; and fora
justification of Virgil, cf. " Meinoires de Trevoux," Jan. 1708. — TB.
CH. iv] ON HUMAN UNDERSTANDING 445
reasonings of a sober man., provided this enthusiast speaks
consistently; and it will be as true to say that a harpy is not
a centaur as to say a square is not a circle. § 2. I reply that
our ideas agree with things. § 3. But the criterion will be
demanded. § 4. I reply further in the first place that this
agreement is manifest as regards the simple ideas of our mind,
for being unable to form them itself, it must be that they are
produced by things acting upon the mind; and in the second
place, § 5. all our complex ideas (those of substances excepted)
being archetypes which the mind itself has made, not intended
to be copies of anything nor referred to the existence of any
thing as to their originals, they cannot fail to be completely
conformed to the things necessary to real knowledge.
Th. Our certitude would be small, or rather nothing, if it
had no other basis of simple ideas than that which comes from
the senses. Have you forgotten, sir, how I have shown that
ideas are originally in our mind, and that indeed our thoughts
come to us from the depths of our own nature, other creatures
being unable to have an immediate influence upon the soul.
Besides the ground of our certitude in regard to universal
and eternal truths is in the ideas themselves, independently
of the senses, just as ideas pure and intelligible do not depend
on the senses, for example, that of being, unity, identity, etc.
But the ideas of sensible qualities, as color, savor, etc. (which
in reality are only phantoms),1 come to us from the senses,
i.e. from our confused perceptions. And the basis of the truth
of contingent and singular tilings is in the succession which,
causes these phenomena of the senses to be rightly united as
the intelligible truths demand.'2 That is the difference which
1 Cf. ante, p. 317 (where the term "phantasies," in line 12, rendered by the
word "notions," would have been better rendered, perhaps, by "phantasms"
or " phantoms "), notes 1 and 2, and infra, p. 459. Schaarschmidt translates:
"Phantasie-Erscheinungen." The term "phantom," or, as it might perhaps
have been translated, "phantasm," — the Greek (ba.i'Taa-fj.a, and the Scholastic
"phantasma," — signifies here a mental modification given or produced
through the agency of the senses, but having no corresponding external
object, i.e. an entirely subjective phenomenon, real as such, but which, since
it corresponds to no objective external reality, has, to a certain extent, the
character of a mere appearance. — TR.
2 Cf. New EMU/*, Bk. IV., chap. 2, § 14, Th. (2), ante, p. 422, note 1.
Leibnitz felt, says Schaarschmidt, that we coiild not be satisfied from a philo
sophical point of view with the old definition of truth as consisting in the
agreement of thought with reality. — TR.
446 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
should be made, while that which you here make between
simple and complex ideas, and ideas complex belonging to sub
stances and to accidents, does not appear to me well founded,
since all intelligible ideas have their archetypes in the eternal
possibility of things.]
§ o. Ph. It is true that our complex ideas need archetypes
outside the mind only when the question concerns an existing
substance which must effectively unite outside us these com
plex ideas, and the simple ideas of which they are composed.
The knowledge of mathematical truths is real, although it re
volves only upon our ideas, and finds nowhere exact circles.
But we are assured that existing things will agree with our
archetypes according as what we suppose therein is found
existing. § 7. This serves to justify the reality of moral
things. §8. Nor are Cicero's "Offices" less conformed to
truth, because no one in the world rules his life exactly
according to the pattern of a virtuous man such as Cicero has
painted for us. § 9. But (it will be said) if moral ideas be of
our invention, what a strange notion shall we have of justice
and temperance?
§ 10. I reply that the uncertainty will be only in the lan
guage, because what is said is not always understood, or
always understood in the same way.
Th. [You might reply also, sir, and much better in my
opinion, that the ideas of justice and temperance are not of
our invention, any more than those of the circle or the
square. I think I have sufficiently shown this.]
§ 11. Ph. As for the ideas of substances existing outside
us, our knowledge is real so long as it is conformed to these
archetypes; and in this respect the mind must not combine
ideas arbitrarily, so much the more as there are very few sim
ple ideas of which we can be certain that they can or cannot
exist together in nature beyond what appears by sensible
observations.
Th. It is, as I have more than once said, because these
ideas, when reason cannot judge of their compatibility or con
nection, are confused, like those of the particular qualities
of the senses.
§ 13. Ph. It is well also as regards existing substances not
to limit ourselves to names or to species supposed to be estab-
CH. iv] ON HUMAN UNDERSTANDING 447
lishecl by names. This makes me return to discussions we
have often enough had regarding the definition of man. For
speaking of an innocent 1 who has lived forty years without giv
ing the least sign of reason, could we not say that he holds
the middle place between man and beast? It would possibly
be thought a very bold paradox, or even a falsehood with very
dangerous consequences. But it seemed to me formerly and
it seems still to some of my friends whom I cannot disabuse
as yet (of the idea) that it is only in virtue of a prejudice
based upon this false supposition that these two names man
and beast signify distinct species, so well marked by real
essences in nature that no other species can intervene between
them, as if all things were thrown into the mould according
to the precise number of these essences. § 14. When these
friends are asked What species of animals these innocents are,
if they are neither men nor beasts, they reply they are innocents,
and that is sufficient. If asked further what they will become
in the next world, our friends reply they are not concerned to
know or inquire. Let them fall or stand to their own master
(Rom. 14:4), who is good and faithful and disposes of his
creatures not according to the narrow limits of our particular
thoughts or opinions, nor does he distinguish them conformably
to the names and species it has pleased us to invent; let it suffice
us that those who are capable of instruction will be called to
render au account of their conduct and will receive their re
ward according to the deeds done in their bodies (2 Cor. 5:10).
§ 15. I shall exhibit to you the rest of their reasonings. The
question (say they) ivhether imbeciles must be deprived of a future
state rests upon two equally false suppositions : first that every
being having the form and external appearance of man is
destined to an immortal state after this life; and second that
everything having a human birth must enjoy this privilege.
Remove these imaginative ideas, and you will see that such
questions are ridiculous and groundless. In fact I think we
shall disallow the first supposition and shall not have the mind
so buried in matter as to believe that eternal life is due to any
form of material mass, so that the mass must have feeling
eternally because moulded upon such a figure. § 16. But the
1 Locke's word is " changeling," Philos. Works (Bonn's ed.), Vol. 2, p. 176
sq., and note. — TR.
448 LEIBNITZ'S CRITIQUE OF LOCKE [BK. IT
second supposition comes to the rescue. We shall say that this
innocent comes from rational parents and that consequently it
must have a rational soul. I know not by what rule of logic
we can establish such a consequence, nor how after that we
should dare to destroy these ill-formed and disfigured produc
tions. Oh, they are monsters, it will be said. Very well, so be
it. But what will this always intractable innocent be? Shall
a defect in the body make a monster, and not a defect in the
mind? This is to return to the first supposition, already
refuted, that the external suffices. A well-formed innocent
is a man, as we believe; he has a rational soul, although it
does not appear; but make the ears a little longer and more
pointed, and the nose a little flatter than usual, then you begin
to hesitate. Make the face narrower, flatter, and longer;
there you are all at once decided. And if the head is per
fectly that of any animal, it is no doubt a monster; and this
is for you a demonstration that it has no rational soul and
that it should be destroyed. I ask you now where to find the
just measure and the final limits bearing with them a rational
soul. There are human foetuses, half beast, half man, others
three parts of which belong to the one, and one part to the
other. How determine precisely the lineaments which indicate
reason? Further, will not this monster be a species midway
between man and beast? And such is the innocent in question.
Th. [I am astonished that you return to this question suffi
ciently examined by us, and that more than once, and that
you have not better catechized your friends. If we distin
guish the man from the beast by the faculty of reason, there
is no middle ground, the animal in question must have it or
not have it; but as this faculty sometimes does not appear,
we judge of it by indices which are not demonstrative of the
truth till this reason manifests itself: for we know by the
experience of those who have lost it and who at last have re
covered its exercise, that its function may be suspended. Birth
and form furnish presumptions of that which is concealed.
But the presumption of birth is effaced (eliditur) by a figure
very different from the human, such as that of the animal was,
born of a woman of Zealand according to Levinus Lemnius l
1 Livin Lemmons — Latin, Levinus Lemnius — 1505-1568, a Dutch physician,
who was very successful in practice, and had in his time a very great repnta-
CH. T] ON HUMAN UNDERSTANDING 449
(Book I., Chap. 8), which had a hooked beak, a long and
round neck, flashing eyes, a pointed tail, and great agility
at first in running about the room. But you will say that
there are some monsters or brothers of the Lombards (as the
physicians formerly called them because it was said that the
women of Lombardy were subject to this kind of childbirth)
who approach more and more the human figure. Very well;
so be it. How then (say you) can the proper limits of the
figure which is to pass as human be determined? I reply
that in a conjectural matter there is no precision. And there
the affair ends. You object that the innocent does not exhibit
reason, and yet passes as a man, but if it had a monstrous
figure, it would not be man, and thus you have more regard
for figure than for reason. But, does this monster exhibit
reason? Certainly not. You see, then, that it lacks more
than the innocent. The defect of the exercise of reason is
often temporal, but it does not cease in those in whom it is
accompanied by a dog's head. For the rest, if this animal
with a .human figure is not a man, there is no great harm in
guarding it during the uncertainty as to its fate. And whether
it has a rational soul or not, God will not have made it for
nothing, and we may say of the souls of men who live in a
state always similar to that of early infancy that their fate
may be the same as that of the souls of those infants who die
in the cradle.
CHAPTER V
OF TRUTH IX GENERAL
§ 1. Ph. For many centuries the question has been asked,
What is truth? § 2. Our friends think it is the joining or
separating of signs according as the things themselves agree
or disagree among themselves. By the joining or separating
of signs must be understood what is otherwise called a propo
sition.
tion. Lemnius relates this marvellous occurrence, which he states was reported
to him by the woman herself, as soon as she had barely recovered, but in which
there must have been some deception, in his De miraculis occultis naturse, Bk.
I., chap. 8, p. 37, Francofurti, 1028, Eng. trans., p. 24, London, 1658. — TR.
2G
450 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
Th. But an epithet does not make a proposition; for example,
the ivise man. But there is a union of two terms, legation
also is different from separation; for saying man, and after an
interval saying ivise, is not a denial. Agreement also, or dis
agreement is not properly speaking what is expressed by the
proposition. Two eggs have agreement and two enemies have
disagreement. The question here concerns an entirely par
ticular mode of agreement or disagreement. Thus I* think
this definition fails wholly to explain the point in question.
But what I find least to my taste in your definition of truth
is that you seek truth in words. Thus the same sense ex
pressed in Latin, German, English, French, will not be the
same truth, and it will be necessary to say with Hobbes,1 that
1 Cf. Leibnitz, DC stilo philos. Nizolii, § 28, ad fin., Gerhardt, 4, 158, Erd-
niaini, (>!) b, Dutens, 4, Pt. I., GO, where, after expressing his belief that " Occam
himself was not more of a Nominalist than Thomas Hobbes now is, who, in
truth, seems to me more than a Nominalist," Leibnitz continues: " Non con
tent us enini cum Nominalibus universalia ad nomina reducere, ipsam rerum
veritatem ait in nominalibus consistere, ac, quod majus est, pendere ab arbitrio
humano, quia veritas pendeat a definitionibus terminorum, definitiones autem
terminorum ab arbitrio humano." Hobbes in his Leviathan (Morley's Uni
versal Library, No. 21), 3d ed., London: Geo. Routledge & Sons, 1887, Pt. 1.,
cliap. 4, p. 24, after speaking of " the imposing of ' names,' and the 'connec
tion of them,'" says: " When two names are joined together into a conse
quence, or affirmation, as thus, ' a man is a living creature ' ... if the latter
name 'living creature,' signify all that the former name 'man' signitieth,
then the affirmation, or consequence, is ' true ' ; otherwise ' false.' For ' true '
and 'false' are attributes of speech, and not of things. . . ." And in the next
paragraph : " Seeing then that truth consisteth in the right ordering of names
in our affirmations, a man that seeketh precise truth had need to remember
what every name he uses stands for, and to place it accordingly." Leibnitz,
probably, had this or some similar passage in mind, in his references to Hobbes'
doctrine, and his statement is a possible and seemingly fair interpretation of
many passages in Hobbes' writings, which passages, however, might be offset
by others oi a different character. Hobbes, nevertheless, seems never to have
gone beyond his nominalistic position, never, at least, so far as consciously to
connect his doctrine of truth with the facts of experience and the reality of
things; while Leibnitz's doctrine of truth has to a certain extent at least an
objective reference in affirming an actual or at least possible existence of the
objects of ideas, cf. ante, pp. 422, note 1, 445, note 2, infra, p. 452, note 1.
For further exposition of Hobbes' doctrine, cf. G. Groom Robertson, Hobbes,
pp. 83-1K), espec. p. 87 (Philos. Classics), Edinburgh: Wm. Blackwood & Sons,
188(5. On the relation of Leibnitz to Hobbes, cf. F. Tunnies, Leibniz und
Hobbes, in the " Philos. Monatshefte," vol. 23, 1887, 557-573 ; see also, " Mind,"
No. 50, April, 1888, pp. 312-314. For two letters of Leibnitz to Hobbes, cf.
Gerhardt, Leibniz, philos. Schrift., 1, 82-87, also, 7, 572-574, where the first
letter is given with an amended text. Leibnitz appended to his Theodice'e a
short piece entitled Reflexions sur Voucranc que M. Hobbes a public en
en. v] ON HUMAN UNDERSTANDING 451
truth depends on the good pleasure of men ; which is to speak
in a very strange manner. You attribute, indeed, truth to God,
who, you will agree with me (I think), has no need of signs.
Finally, I have been astonished already more than once at the
disposition of your friends who are pleased to make essences,
species, and truths nominal.
Ph. Do not advance too fast. Under signs they include
ideas. Thus, truths will be either mental or nominal, accord
ing to the species of signs.
Th. [We shall then have also literal truths, which may be
distinguished as truths upon paper or parchment, of ordinary
black ink or of printer's ink, if truths must be distinguished
by signs. It were then better to place truths in the relation
between the objects of ideas which causes the one to be or not
to be included in the other. That does not depend upon
languages, and is common to us with God and the angels;
and when God manifests a truth to us we shall acquire that
which is in his understanding, for although there is an infi
nite difference between his ideas and ours, as regards perfec
tion and extent, it is always true that they agree in the same
relation. It is, then, in this relation that truth must be placed,
and we can distinguish between the truths which are inde
pendent of our good pleasure, and between the ex2)ressions
which we invent as seems good to us.]
§ 3. Ph. It is only too true that men, even in their minds,
put words in the place of things, especially when the ideas
are complex and indeterminate. But it is also true as you
have observed, that then the mind contents itself with the
indication only of the truth, without for the present under
standing it, in the persuasion that it depends upon itself to
understand it when it will. For the rest, the act which takes
place in affirming or denying is more easily conceived by re
flecting upon what goes on in us, than explained in words.
Therefore, you do not take it ill that in default of some
thing better we have spoken of joining together or of sepa
rating. § 8. You will also agree that propositions at least
may be called verbal, and that, when they are true, they are
A>i(/lois, de la libcrte, de la necessite ct du hasard, c,f. Gerhardt, 0, 388-399,
Knlmann, r>29-<>34, Janet, CEavres phllos. de Leibniz, 2, 424-437, Dutens, 1,
415-429 (in Latin). — TR.
452 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
both verbal and also real, for, § 9. falsehood consists in joining
names otherwise than as their ideas agree or disagree. § 10.
\Yords are at least great vehicles of truth. §11. There is also
a moral truth, which consists in speaking of things according
to the persuasion of our mind; there is finally metaphysical
truth which is the real existence of things in conformity to
the ideas we have of them.
Tli. [Moral truth is by some called veracity, and metaphysi
cal truth is commonly taken by the metaphysicians as an
attribute of being, but it is an attribute very useless and
almost void of meaning. Let us content ourselves with seek
ing truth in the correspondence of the propositions in the
mind with the things in question. It is true that I have also
attributed truth to ideas in saying that ideas are true or false ;
but then I mean, in reality, the truth of propositions affirming
the possibility of the object of the idea. In the same sense
we can say also that a being is true, that is to say, the propo
sition affirming its actual, or at least, possible existence.] 1
CHAPTER VI
OF UNIVERSAL PROPOSITIONS, THEIR TRUTH AXD CERTITUDE
§ 2. Ph. All our knowledge is of general or particular
truths. We can never make the former, which are the most
important, well understood, and can ourselves, indeed, very
rarely comprehend them save as they are conceived and ex
pressed by words.
Th. [I think that other marks also can produce this effect;
we see it in the characters of the Chinese. A universal char-
1 Cf. New Essays, Bk. II., chap. 32, ante, p. 281, and notes; also Bk. III.,
chap. 3, ante, p. 317, note 3; and Bk. IV., chap. 1, ante, pp. 397-8. Locke in the
first of these passages agrees with the view of Aristotle, De Interpret., 1, l(>a,
12, that truth or falsity is predicable not of single ideas, but only of their union
in judgments or propositions: and Leibnitz in the present passage maintains
essentially the same doctrine in saying that by the truth he attributes to ideas
he means the truth of the propositions affirming the possibility of the objects
of the ideas. Such " true " or " false " ideas must, then, be regarded simply
as abbreviated propositions, or as tacitly involving propositions. The idea of
the decahedron (cf. ante, p. 315, and note 1) is false, although we have its
nominal definition, because the figure is impossible. — TR.
CH. vi] OX HUMAN UNDERSTANDING 453
act eristic 1 very popular and better than theirs might be intro
duced if small figures were employed in the place of words,
which would represent visible things by their lines, and the
invisible by the visible which accompany them, adding thereto
certain additional marks suitable to make understood the flex
ions and the particles. This would be of service at first for
easy communication with distant nations; but if introduced
also among us without, however, renouncing ordinary writing,
the employment of this mode of writing would be very useful
in enriching the imagination, and in giving thoughts less surd
and verbal than we now have. It is true that the art of draw
ing not being known by all, it follows that, excepting the
books printed in this way (which everybody would soon learn
to read), everybody could not avail themselves of it otherwise
than by a method of printing, i.e. having the figures all en
graved ready for printing upon paper, and adding thereto
afterwards with the pen the marks of the flexions or particles.
But in time everybody would learn the plan in youth, so as
not to be deprived of the convenience of this figured character,
which would speak in truth to the eyes, and would be very
agreeable to the people, just as in fact the peasants already
have certain almanacs, telling them without words much that
they ask; and I remember to have seen some satirical impres
sions in copper-plate which possessed a somewhat enigmatical
character in which there were figures significant of themselves,
mingled with words,2 while our letters and the Chinese char
acters are significant only by the will of -men (ex institute) .
§ 3. Ph. [I think your thoughts will some day be carried
out, so agreeable and natural appears to me this icriting, and
it seems to be of no little consequence for increasing the per
fection of our mind, and rendering our conceptions more real.]
But to return to general knowledge and its certainty, it will
be proper to remark that there is a certainty of truth and also
a certainty of knowledge. When words are so joined in propo
sitions that they express exactly the agreement or disagree-
1 Cf. ante, p. 375, notel.
- Probably something similar to what is now known by the term " Rebus."
For a brief statement of the development of writing from the picture stage,
its earliest form, to the alphabetic as we now have it, cf. E. Benj. Andrews,
Institutes of Gen. Hist., chap. 2, § 13, p. 49. 2d ed. Boston: Silver, Burdett &
Co., 1888. — TR.
454 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
inent as it really is, it is a certainty of truth; and. the cer
tainty of knowledge consists in perceiving the agreement or
disagreement of ideas so far as it is expressed in propositions.
This is what we ordinarily call being certain of a proposition.
Th. [In fact this last kind of certainty will also suffice with
out the use. of words, and is nothing else than a perfect knowl
edge of the truth ; while the first kind of certainty appears to
be nothing else than the truth itself.]
§ 4. Ph. Now as we cannot be assured of the truth of any
general proposition, unless we know the precise limits of the
signification of the terms of which it is composed, it will be
necessary for us to know the essence of each species, which is
not difficult as regards the simple ideas and the modes. But in
substances wherein a real essence distinct from the nominal
is supposed to determine the species, the extent of the gene
ral term is very uncertain, because we do not know this real
essence; and consequently in this sense we, cannot be assured
of any general proposition made upon the basis of these sub
stances. But when we suppose the species of substances to
be nothing else than the reduction of substantial individuals
into certain sorts, arranged under different general names
according as they agree with the different abstract ideas which
we designate by these names, we cannot doubt whether a prop
osition, well known as it should be, is true or not.
Th. [I do not know why you, sir, return again to a point
sufficiently discussed by us, and which I believe an empty one.
But, after all, I am very glad of it, because you give me an op
portunity very suitable (it seems to me) to disabuse you anew.
I say then to you that we can be assured, for example, of a
thousand truths regarding gold, or that body whose internal
essence makes itself known by the greatest weight known here
below, or by the greatest ductility, or by other marks. For
we say that the body of the greatest known ductility is also
the heaviest of all known bodies. It is true that it is not
impossible that all which has hitherto been noticed in gold
will some day be found in two bodies distinguishable by other
new qualities, and that thus gold would no longer be the low
est species, as it has hitherto been regarded provisionally.
We might also, if the one kind remained rare, and the other
became common, think it proper to reserve the name of
en. vi] ON HUMAN UNDERSTANDING 455
true gold to the single rare species, in order to retain it in
use as money by means of new assays which would be suited
to it. After which we shall not doubt, also, that the internal
essence of these two species is different; and if indeed the
definition of an actually existing substance should not be
fully determined in all respects (as in fact, that of men is not
as regards the external figure), we should not cease to have
an infinite number of general propositions upon its subject,
which would follow from reason and the other qualities which
we recognize in it. All that we can say regarding these gen
eral propositions is, that in case man is taken as the lowest
species and restricted to the race of Adam, we shall have no
properties of man such as are named in quarto mod 'o,1 or may
1 The term in quarto modo, here used by Leibnitz, refers to a classification
of propria — l<5ia, properties — existent in the time of Porphyry, 233-304, though
not accepted by him, — cf. Ei<rayu>-y»?, chap. 4, 4«, 14 (in Aristotle, ed. Berl.
Acad., Vol. 4, p. 4) : TO Se I&LOV Sicupoucri. rerpa^d)? . . . (18.) reraproi1 8e e<p' ov <rvv-
5e5pa/XT)Ke TO /xoi'a) KOLL navrl Kal del, (*>s T<a dvOpiatru) TO ye\acrTiK6v . . . (22.) TauTa 8e Kal
Kvpuos ISid 4>Tj(nv, QTL Kal dvTiaTpefyei — and due, perhaps, to some one of the old
Peripatetics, and prevalent in different forms in the Middle Age, according to
which classification as given by Porphyry there were four classes: 1. Propria
belonging to one species only, but not to every individual thereof, as yram-
matical to man ; 2. Propria belonging to every individual of the species, but
not to this species alone, as biped to man ; 3. Propria belonging to one species
only and to every individual thereof, but not always, as hoary to man ; 4. Pro
pria belonging to one species only, to every individual thereof, always, as
rinibiiittf or rixible to man.
The propria of this fourth class — quartus modus — are, each, of equal
breadth with its subject, and, though no part of the essence of the species of
which they are predicated, — man, for example, without the proprium risible,
still being man, — as a matter of fact belong to every individual of the species
on all occasions, and to no individual of any other species. Propositions predi
cating such propria are judgments in A, according to Archbishop Thomson's
terminology, of the type "Common Salt is Chloride of Sodium," and are of
course convertible.
Propria of this fourth class alone, i.e. propria each of which would be coinci
dent with its subject so as to be enouncible in a judgment in A — reciprocal — con
stitute the fourth predicable, and answer to the ISiov of Aristotle and Porphyry,
and the proprium of Appuleius, Marcianus Capella and Boethius. These
writers, with the exception of Aristotle, to whom probably the four-fold divis
ion of propria was unknown, regard the other three classes, which were pro
pria according to the Middle Age schoolmen, as accidents, — accidentia, vv^fie-
iSr/KOTa, — a fact which explains the somewhat peculiar language of Leibnitz:
"We shall have no properties of man such as (of the sort that) are named in
quarto jnodo," etc. Leibnitz's thought is this : " In the case of ' man ' " taken
as the lowest species — species infima — and " limited to Adam's race, there is,
except provisionally, no such proprium. ' Sole-rational-animal ' would be,
provisionally, such a proprium, because up till now we know no men whom it
456 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
be enounced concerning him by a reciprocal or simply conver
tible proposition, unless provisionally, as in saying: man is
the only rational animal. Taking man as those of our race,
the provisional consists in the assumption that he is the only
rational animal of those known to us; for we might some
day find other animals who would have in common with the
posterity of men of the present time all that which we have
hitherto observed in them, but who would have another origin.
It is as if the so-called Australians should overrun our coun
tries : in all likelihood we should then discover some means of
distinguishing them from ourselves. But in case this should
not happen, and supposing that God had forbidden this mixt
ure of these races, and that Jesus Christ had redeemed ours
only, it would be necessary to try to make some artificial marks
in order to distinguish between them. There would doubtless
be an internal difference, but as it would not make itself recog
nizable, we should be reduced to the extrinsic denomination of
birth alone which we should try to accompany with a durable
artificial mark that would give an intrinsic denomination, and
a constant means of distinguishing our race from the others.
These are all fictions, for we have no need to recur to these
distinctions, being the only rational animals of this globe.
Yet these fictions are useful in knowing the natures of ideas,
substances, and truths general in their character. But if man
were not taken as the loivest species nor as that of the rational
animals of the race of Adam, and if, instead of that, he signified
a genus common to several species, which belonged now to a
single known race, but which might belong also to others
distinguishable either by birth or even by their natural marks,
as, for example, in the case of the supposed Australians;
then, I say, this genus would have reciprocal propositions, and
the present definition of man would not be provisional. It is
would not fit, and know of no other species any of whose individuals it would
fit. Only provisionally, however, for future discoveries may show, in either
of these respects, that ' sole-rational-animal,' and ' man ' are not exactly coinci
dent concepts." On the whole subject, cf. Prantl, Gesch. d. Loyik, Vol. 1,
pp. 343, 395, 425, 581, 584, 630, 674, 676/696, Vol. 2, pp. 342-343, Vol. 3,
p. 102, Vol. 4, p. 241, note 383; Aldrich, Artis Logicse Rudimenta, ed. Mansel,
Oxford, 1856, pp. 32-34.
I would add that for much of the material as well as of the language of the
above note, I am indebted to the kindness of Pres. E. B. Andrews of Brown
University. — TR.
CH. vi] OX HUMAN UNDERSTANDING 457
the same with gold; for suppose that some day there were two
kinds of it distinguishable, the one rare and hitherto unknown,
the other common and perhaps artificial, discovered in the
course of time; then suppose that the name gold should
continue for the present species, i.e. for the natural and rare
gold, in order to preserve by its means the commodity of gold
money, based upon the rarity of this substance, its definition
known hitherto by intrinsic denominations would have been
provisional only, and should be augmented by new marks
which will be discovered, to distinguish the rare gold or the
ancient species from the new artificial gold. But if the name
gold should then remain common to the two species, i.e. if
by gold you mean a genus of which up to the present time we
know no subdivision, and which we now take as the lowest
species (but only provisionally until the subdivision is known)
and if some day a new species were found, i.e. an artificial
gold, easy to make, and which might become common ; I say
that in this sense the definition of this genus should not be
judged provisional, but perpetual. And indeed, without
troubling ourselves with the names man or gold, whatever
name is given to the genus or to the lowest known species,
and even if none should be given them, what has just been
said would be always true of ideas, genera or species, and
species will be defined provisionally only by the definitions of
genera. But it will always be allowable and reasonable to
assume, by means of a reciprocal proposition, that there is a
real internal essence belonging either to the genus or the
species, which makes itself known ordinarily by external marks.
I have assumed hitherto that the race does not degenerate or
change; but if the same race passed into another species, we
should be so much the more obliged to recur to other marks
and denominations intrinsic or extrinsic, without confining
ourselves to the race.
§ 7. Ph. Complex ideas, which the names we give to the
species of substances justify, are collections of ideas of certain
qualities which we have observed coexisting in an unknown sub
stratum which we call substance. But we cannot know cer
tainly what other qualities coexist necessarily with such com
binations, unless we can discover their dependence as regards
their primary qualities.
458 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
Th. I have already remarked before that the same (diffi
culty) is found in the ideas of accidents, whose nature is a
little abstruse, as, for example, are the figures in geometry;
for when the question concerns, for example, the figure of a
mirror which collects all the parallel rays into one point as a
focus, many properties of this mirror may be found before its
construction is known, but we shall be uncertain, about many
other relations it may have, until we find in it that which
corresponds to the internal constitution of substances, i.e. the
construction of this figure of the mirror, which will constitute
as it were the key to ulterior knowledge.]
Ph. But if we had known the internal constitution of this
body, we should have found therein only the dependence
which the primary, or what you call manifest, qualities may
have, i.e. you would know what size, figure, and moving force
depend thereupon; but we should never know the connection
which they may have with the secondary or confused qualities,
i.e. with the sensible qualities, as colors, tastes, etc.
Th. The fact is, you still assume that these sensible quali
ties, or rather the ideas we have of them, do not depend upon
figure and movement in a natural way, but only upon the
good pleasure of God, who gives us these ideas. You appear
to have forgotten, sir, the remonstrance I have more than once
made to you against this opinion, in order to make you think
rather that these sensitive ideas depend in detail upon the fig
ures and movements, and express them exactly, although we
cannot distinguish therein this detail in the confusion of
too great a multitude and minuteness of mechanical actions
which strike our senses. But if we had reached the internal
constitution of some bodies, we should see also how they must
have these qualities, which would themselves be reduced to
their intelligible reasons ; although it would never be in em
power to recognize them sensibly in these sensitive ideas
which are a confused resultant of the actions of bodies upon
us, as, now that we have the perfect analysis of green into blue
and yellow,1 and have scarcely anything more to ask in regard
to it save as related to these ingredients, we are, however,
incapable of analyzing the ideas of blue and yellow in our
1 Of. ante, p. 320, note 1 : also Leibnitz's letter to Th. Burnett, without date,
but written, according to Gerhardt, in 1699, G., Leibniz, philos. Schrift., 3,
250. — TR.
CH. vi] ON HUMAN UNDERSTANDING 459
sensitive idea of green, for the very reason that it is a con
fused idea. It is much the same as we cannot analyze the
idea of the teeth of the wheel, i.e. of the cause, in the percep
tion of an artificial transparency, which I have noticed among
the clock-makers, made by the rapid rotation of a cog-wheel,
which makes the teeth disappear, and an imaginary continu
ous transparency appear in their place, composed of the suc
cessive appearances of the teeth and their intervals, but in
which the succession is so rapid that our phantasy cannot dis
tinguish it. We find then, indeed, these teeth in the distinct
notion of this transparency, but not in this confused sensitive
perception, whose nature is to be and to remain confused;
otherwise if the confusion ceased (as if the motion were so
slow that we could observe its parts and their succession)
this notion, i.e. this phantasm1 of a transparency would no
longer exist. And as there is 110 need of imagining that
God for his good pleasure gives us this phantasm, and that
it is independent of the movement of the teeth of the wheel
and their intervals, and as, on the contrary, we conceive it
to be only a confused expression of what takes place in this
movement, an expression, I say, that consists in the fact that
these successive things are confounded in an apparent simul
taneity: it is thus easy to think that it will be the same as
regards other sensitive phantasms, of which we have not as yet
so perfect an analysis, as of colors, tastes, etc. For, to speak
the truth, they deserve this name phantasms rather than that
of qualities or even of ideas. And it would suffice us in all
respects to understand them as well as this artificial trans
parency, without its being reasonable or possible to claim
a further knowledge of them; for to desire these confused
phantasms to abide, and yet to distinguish therein their in
gredients by the phantasy itself, is a contradiction, is a desire
to have the pleasure of being deceived by an agreeable per
spective, and to desire that at the same time the eye see the de
ception, which would destroy it. It is a case, in short, where —
nihilo plus a.iras
Quam si des operam, ut cum ratione insanias.2
1 Cf. ante, p. 445, note 1. Schaarschmidt here translates: " Phantasie-
Erscheinung " ; in line 17 of this page, " Phantasievorstellung " ; in Hues 24, 26,
31, " Erscheinnngen." — TR.
'2 Terence, Eun.t 1. 1. 17, 18. — TR.
460 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
But it often happens that men seek nodum in scirpo 1 and make
difficulties where there are none, by demanding the impossible,
and afterwards complaining of their impotence and of the
limits of their light.
§ 8. Ph. All gold is fixed is a proposition, the truth of which
we cannot certainly know. For if gold signifies a species of
things, distinguished by a real essence, which nature has
given it, we are ignorant what particular substances are of
this species. Thus, although this may be gold, we cannot affirm
it with certainty. If we take gold as a body endowed with a cer
tain yellow color, malleable, fusible, heavier than any known
body, it is not difficult to know what is or is not gold,; but
with all that, no other quality can be affirmed or denied with
certainty of gold, than that which has a connection with this
idea, according to a connection or incompatibility which may
be discovered.2 Xow fixity having no known connection with
color, weight, and the other simple ideas which I have sup
posed to constitute the complex idea we have of gold, it is
impossible that we can know with certainty the truth of this
proposition, that all gold is fixed.
Tli. We know almost as certainly that the heaviest of all
bodies known here below is fixed, as we know certainly that
it will be light to-morrow. This is because we have tried it a
hundred thousand times ; it is an experimental certainty, and
of fact, although we do not know the bond which unites the
fixity with the other qualities of this body. Moreover, it is
unnecessary to oppose two things which agree and amount to
the same thing. When I think of a body, which is at the
same time yellow, fusible, and which resists the cupel, I think
of a body whose specific essence, although unknown in its
interior, makes these qualities emanate from its depths, and
makes itself known confusedly at least by means of them. I
see nothing wrong in that, nor anything which requires you to
return so often to the charge in order to attack it.
§ 10. Ph. It is enough for me now that this knowledge of
the fixity of the heaviest of bodies is not known to us by the
i Of. ante, p. 220, note 1. — TR.
- According to the texts of Gerhardt and Erdmann. Jacques and Janet
rend: " Qne ce qni a avec cette idee une connexion ou une incompatibility
qu'on pent decouvrir " : i.e. than that which has a discoverable connection
or incompatihility with this idea. — TR.
CH. vr] ON HUMAN UNDERSTANDING 461
agreement or disagreement of ideas. And I for myself think
that among the secondary qualities of bodies and the powers
relating to them there cannot any two be named whose neces
sary coexistence or incompatibility can be known with cer
tainty, except the qualities which belong to the same sense
and necessarily exclude one another, as when you can say that
what is white is not black.
Tli. I believe, however, that you might perhaps find them ;
for example, every palpable body (or that which may be felt
by touch) is visible. Every hard body makes a noise when
struck in the air. The tones of strings or wires are semi-pro
portional to the weights which cause their tension. It is true
that what you ask succeeds only as far as you conceive distinct
ideas united with confused sensitive ideas.
§ 11. Ph. It is not always necessary to think that bodies
have their qualities by themselves independently of anything
else. A piece of gold, separated from the impression and
influence of every other body, would immediately lose its
yellow color and weight; perhaps, also, it would become
friable and lose its malleability. You know how vegetables
and animals depend upon the earth, air, and sun ; how do you
know whether the very distant fixed stars have not also an
influence upon us?
Th. This is a very excellent remark; and if the contexture
of certain bodies were known to us, we could not judge wholly
of their effects without knowing the interior of those which
touch and traverse them.
§ 13. Ph. Our judgment, however, may go further than
our knowledge. For people sedulous in ma,king observations
can penetrate farther, and by means of certain probabilities
resulting from an exact observation and by certain hints pur
posely put together, often make just conjectures regarding
that which experience has not yet discovered to them ; but it
is always only conjecture.
Th. But if experience justifies these consequences in a con
stant manner, do you not find that you can acquire certain
propositions by this means? Certain, I say, at least as those
which assert, for example, that the heaviest of our bodies is
fixed and that the one which is after it the heaviest is volatile,
for it seems to me that the certainty (understanding it as moral
4(i2 LEIBMTZ'S CRITIQUE OF LOCKE [BK. iv
or physical), but not the necessity (or metaphysical certainty) of
these propositions which are learned by experience alone and
not by analysis and the bond of ideas, is established among
us and with reason.1
CHAPTER VII
OF PROPOSITION'S CALLED MAXIMS OK AXIOMS
§ 1. Ph. There is one species of propositions which under
the name of maxims or axioms pass as principles of science,
and because they are self-evident^ we have, been contented to
call them innate, although no one that I know of has ever tried
to show the reason and ground of their extreme clearness,
which forces us, so to speak, to give them our consent. It is
not, however, useless to enter into this investigation and to
see whether this great evidence is peculiar to these proposi
tions alone, as also to examine how far they contribute to
our knowledge.
Th. This investigation is very useful and very important.
But you must not suppose, sir, that it has been entirely
neglected. You will find in a hundred places that the Scho
lastics have said that these propositions are evident ex ter-
minis, as soon as the terms are understood, so that they
were persuaded that the force of conviction was grounded in
the knowledge of the terms, i.e. in the connection of their
ideas. But geometers have done very much more: that is
1 Metaphysical and moral or physical certainty differ as the certainty of the
truths of reason and the truths of fact. The truths of reason ground them
selves in the necessities of thought, and their certainty is accordingly absolute.
The truths of fact, in Leibnitz's view, rest upon the divine choice of the best,
and have an evidence merely relative and established with vthe aid of experi
ence: their necessity is accordingly only hypothetical. Cf. New Essays, Bk.
II.. chap. 21, § 8, Th., ante, pp. 179-180, and § 13, Th., ante, p. 183. The prin
ciple upon which the whole matter depends is the famous distinction of the
mediaeval scholastics between the understanding and the will of God, a prin
ciple to which Leibnitz very often recurs, especially in order to maintain the
contingency of the world, and to escape from the universal fatalism of
Spinoza. According to this principle, the understanding of God is the source
of the necessary truths, and the will of God the source of the contingent truths.
The distinction, however, does not solve the problem either of the contingency
of tlie physical universe or of the moral freedom of man. — TK.
CH. vn] ON HUMAN UNDERSTANDING 403
they have undertaken very often to demonstrate them.1 Pro
clus already attributes to Thales of Miletus, one of the
oldest known geometers, the wish to demonstrate the proposi
tions which Euclid has since assumed as evident.2 It is said
that Apollonius has demonstrated other axioms, and Proclus
has also done so. The late Mr. Roberval, already eighty
years old or thereabouts, intended to publish the new ele
ments of geometry of which I think I have already spoken to
you.3 Perhaps the "New Elements" of Arnauld, which at
that time made some stir, had contributed thereto.4 He
exhibited specimens of them in the Royal Academy of Sciences,
and some found fault that assuming this axiom, if equal mag
1 Leibnitz frequently refers, both in the New Essays and elsewhere, to-
the demonstrability of the axioms, and the thought was evidently a favorite
one with him. It is a weighty thought, too; for all real advance in specula
tive and truly and lastingly constructive thinking rests upon just this " work
ing-over of the notions," as Herbart expresses it, this deeper penetration into
their real meaning and content, and its exposition in the simplest possible
intelligible forms. — TR.
- Proclus cites Thales of Miletus in prop. XV., theor. VIII., of his In
primu.m Euclidis Elementorum lib. Cornmentarii, ex recog. G. Friedlein,
p. 299. Thales, c. 624-c. 550 B.C., was the founder of the Greek geometry, astron
omy, and philosophy. For his geometry, cf. G. J. Allman, Greek Geometry
from Thales to Euclid, Dublin, 1889; for his philosophy, cf. Zeller, Philos. d.
'Griech., I., 1 [Vol. 1], 180-1%, 5th ed., Leipzig, 1892. — TR'.
3 Cf. ante, p. 107, note 1. — TR.
4 The work of Antoine Arnauld, 1612-1694, here referred to is the Nouveant
Elemens de Geometric, Paris, 1661, mentioned among the most prominent
books of that time by Ch. Wolf in his Kurzer Unterricht i\ d. vornehmsten
math. Schrift., Wien, 176.'). Arnauld was an excellent mathematician, an able
philosopher and theologian, a celebrated controversialist, and the indefatigable
champion and mouthpiece of the Jansenists against the Jesuits. A zealous
Catholic, he repeatedly tried to convert Leibnitz to that faith. Leibnitz's
correspondence with him contains important matter regarding his own philos
ophy. It was originally edited and published by C. L. Grotefend, Briefwechsel
z< Leibniz, Arnauld u. d. Landgrafen Ernst v. Hessen-Rheinfels aus d. Hcmd-
schriften der Koniyl. Bibliothek z. Hannover, Hanover, 1846, and was re
printed conformably to Grotefend's text by Janet, (Euvres philos. de Leibniz,
Vol. 1, pp. 577-691, and, with a new comparison of the original Mss., by Ger-
hardt, Leibniz, philos. Schrift., Vol. 2, pp. 11-138; cf. also his Einleitung, ib.
p. 5 (<q., and Vol. 1, p. 65, and for Leibnitz's first letter, unanswered, to Ar
nauld, ib. 68-82 (Grotefend, op. cit. 137 sq. ).
Arnauld's CEavres completes, with a life by Larriere, appeared at Paris and
Lausanne, 1775-1783, 45 vols., Vols. 38-40 containing the philosophical works.
Of these the most important are : Des vraies et desfausses idees, 1683, directed
against Malebranche, in which Arnauld develops his doctrine of perception and
attacks the theory of representative ideas, on which cf. Hamilton's Reid,
8th ed., Vol. 1, pp. 295-298, Vol. 2, pp. 823 b, 963; Reflexions philos. et theoloa.
xur le nouveau syateme de la nature et de la (/race da P. Malebranche, 1685-
464 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
nitudes are added to equals, equals arise therefrom, he demon
strated this other which is considered equally evident : if
equals are taken from equal magnitudes, equals remain. It was
said he should have assumed both or demonstrated both. But
I was not of that opinion, and I believed that it was always
so much gained to have diminished the number of the axioms.
Addition is no doubt anterior to subtraction and more simple,
because the two terms are employed in addition in the same
way, which is not the case in subtraction. Arnauld did
the opposite of Roberval. He assumed still more than
Euclid. As for the maxims, they are sometimes taken as
established propositions whether evident or not. That may
be well for beginners whom scrupulousness holds back; but
when the establishment of science is the question, it is a dif
ferent matter. Thus it is that they are often taken in ethics
and even among the logicians in their topics, in some of which
there is a good supply, but a part of which contain enough of
them vague and obscure. For the rest, I said a long time
since publicly and privately that it is important to demon
strate all our secondary axioms, which we ordinarily use,
by reducing them to the primitive or immediate and indemon
strable axioms, which I recently and elsewhere called the
identicals.
§ 2. Ph. Knowledge is self-evident when the agreement or
disagreement of ideas is immediately perceived. § 3. But
there are truths, not recognized as axioms, which are none
the less self-evident. Let us see if the four species of agree
ment of which we spoke not long since (chap. 1, § 3, and
chap. 3, § 7), viz. : identity, connection, relation, and real ex
istence, furnish us with them. § 4. As for identity or diver
sity, we have as many evident propositions, as we have dis
tinct ideas, for we can deny both, as in saying man is not a
horse, red is not blue. Further the statement what is, is, is as
evident as the statement a man is a man.
Th. It is true, and I have already remarked that it is as
evident to say ecthetically in particular A is A, as to say in
1686 ; Objections contre Descartes ; and La Logiqye ou I' Art de Penser, or the
celebrated Port Royal Logic, 1662, written in conjunction with Nicole (cf.
infra, p. 530, note 1), the best specimen of the logic of the Cartesian school.
It has been translated into English most admirably by Prof. Thos. Spencer
Baynes. — TR.
CH. vn] ON HUMAN UNDERSTANDING 465
general : it is ivhat it is. But to deny the subjects of different
ideas one of another is not always certain, as I have already
remarked; as if any one wished to say, the trilateral (or that
which has three sides) is not a triangle, because, in fact, tri-
laterality is not triangularity; again, if any one had said: the
pearls of Slusius 1 (of which I spoke to you not long since)
are not the lines of the cubic parabola, he would have been mis
taken, and yet that would have appeared evident to many
people. The late Mr. Hardy,2 Conseiller au Chatelet de Paris,
an excellent geometer and orientalist and well versed in
the ancient geometers, who has published the commentary
of Marinus on the Data of Euclid, Avas so prepossessed with
the fact that the oblique section of the cone called an ellipse
is different from the oblique section of the cylinder, that the
demonstration of Serenus 3 appeared to him paralogistic, and I
could gain nothing against him by my remonstrances : as he
was nearly as old as Roberval, when I saw him, and I was a
very young man, a difference which could give me very little
persuasive power as regards him, although in other respects I
was on very good terms with him. This example may show
in passing what prepossession may do even in the case of clever
people, for he was truly prepossessed, and Hardy is spoken of
1 Cf. ante, p. 387, note 1. — TR.
- Claude Hardy, born near the close of the sixteenth century, died in 1(578,
was a barrister by profession, and became in 1(526 " Conseiller au Chatelet de
Paris." He was acquainted with not less than thirty-six ancient and modern
languages, and made a profound study of mathematics. Descartes chose him
as one of his judges in his controversy with Fermat, in 1(598, over Fermat's
De maximis et mlnimis. Hardy published the Data Euclidis, Greek text, with
Latin trans., together with the commentary of Marinus, the Neo-Platonist
(cf. Zeller, Philos. d. Griech., III., 2 [Vol. 6], 833, 3d ed., 1881), who lived in
the fifth century, and was a disciple and the successor of Proclus (cf. ante,
p. 108, note 2), at Paris, 1625, 4to. Leibnitz speaks of Hardy as an " homme
de merite, grand geometre, et grand orientaliste," cf. Dutens, 5, (510.— TR.
3 Serenus of Antissa, in the island of Lesbos, a Greek geometer, who lived
in the fourth century, was the author of two treatises, De Sectione-Cylindri
et Coni, libri duo, which, according to Brunet, appeared, together with the
Conies of Apollonius of Perga, the Lemmas of Pappus of Alexandria, and the
commentaries of Eutocius of Ascalonita, at Bonn, 1566, fol., reprinted at Pis-
toja, 1(596, fol., and afterwards edited and published by Halley, Oxford, 1710,
fol. Hardy could not have seen either of the last two editions, since he died
in 1678, but possibly he may have been acquainted with that of 1566; and, if
not, then, as Schaarschrnidt says, he must refer to Mersenne's Synopsis,
Paris, 1644, which contains, pp. 276-312, an abridgment of Apollonius and
Serenus. — TR.
2n
406 LEIBNITZ'S CRITIQUE OF LOCKK
with esteem in the letters of Descartes.1 But I brought him
forward only to show how we may be mistaken in denying one
idea of another, if we have not thoroughly enough examined
them where it is necessary.
§ ~>. Pli, As regards connection or coexistence, we have very
few self-evident propositions; there are, however, some, and
it appears to me that this is a self-evident proposition : two
bodies cannot be in the same place.
Tli. Many Christians contest the point with you, as I have
already remarked, and even Aristotle and those who after him
admit real and exact condensations, reducing one and the same
entire body into a smaller place than it before filled, and those
who, as the late Mr. Comenius '2 has done in a little book writ
ten expressly for the purpose, claim to overthrow8 modern
natural philosophy by the experiment of the air-gun, cannot
be expected to agree therewith. If you take the body as the
impenetrable mass, your statement will be true, because it
will be identical or nearly so; but that the real body is such
will be denied you. At least it will be said that God could
1 Schaarschmidt thinks that Leibnitz here confounded Hardy with Roherval,
whom he had mentioned just before. Descartes frequently mentions Hardy
in his letters, <•/., for example, Pt. I., epist. Ill, Pt. II., epist. 61, 98, 101, 10*.
Pt. III., epist. 34, 60, 63, etc. ; he also corresponded with him, and doubtless
valued him highly, as witness his choice of him as arbiter in his controversy
with Fermat, but he nowhere in his letters appears expressly to praise him:
while he speaks thus of Roberval in Lib. III., epist. 56, ad .Fermatium : " qui
procul dubio inter primaries seculi nostri geometras censeri debet." — TK.
- John Amos Comenius, 1592-1671, the last bishop of the old Moravian and
Bohemian Brethren, devoted himself chiefly to the reform and regulation of
public education and instruction, and wrote many works on pedagogy, which
he collected and published under the title Opera, didactica omnia, Amsterdam,
1657. 4 vols.. t'ol. He also did some work in physical science, publishing his
JJi.s<juisiti<> de raloi'is et fri yen-is natura, Amsterdam, 1659, 12mo, which the
writer in Michaud, Bioy. Unit:., 9, 1345, says is the only one of his physical
works deserving to be in demand, and his Physicse ad lumen divinum rffor-
HKttse synopsis, Leipsig, 1633, and Amsterdam, 1643, Eng. trans., London. 1651,
which is, perhaps, the book to which Leibnitz here refers. For Leibnitz's esti
mate of a portion of the writings of Comenius, cf. Dutens, 5, 181. For an
account of his life and work,';?'. S. 8. Laurie, Comenius. Hift Life and Educa
tional Works, 4th ed. (Pitt Press Series), Cambridge, Univ. Press, 1893: also a
reprint of the same, with five portraits, a somewhat extended and annotated
bibliography, and photographic reproductions of pages from early editions of
Comenius' works, published by C. W. Bardeen, Syracuse, X. Y.. 1893. — TK.
3 Gerhard t reads "reserver," probably a Ms. or typographical error: Erd-
mann. Jacques, and Janet read '' renverser," which, as the context requires,
lin- translation follows. — TR.
en. vn] ON HUMAN UNDERSTANDING 467
make it otherwise, so that this impenetrability will be ad
mitted only as conformed to the natural order of things which
(rod has established and of which experiment assures us,
although elsewhere it would be necessary to admit that it is
also very conformable to reason.
§ (>. Ph. As for the relations of the modes, mathematicians
have formed many axioms upon the one relation of equality,,
like that of which you have just spoken, that if equals be
taken from equals the remainders are equal. But it is not less
evident, 1 think, that one and one are equal to two, and that if
from the five fingers of one hand you take away two and then
two others from the five fingers of the other hand, the number
of the fingers remaining will be equal.
Tit. That one and one make two, is not properly a truth,
hut it is the definition of tivo ; although it is true and evident
tha.t it is the definition of a possible thing. As for the axiom
of Euclid applied to the fingers of the hand, I willingly admit
that it is as easy to conceive what you say of the fingers as
to see it in the case of A and B; but in order not to do often
the same thing, you observe it generally, and afterwards it is
sufficient to make subsumptions. Otherwise, it is as if you
preferred calculation by particular numbers to universal rules,
which would be obtaining less than is possible. For it is of
more account to solve the general problem: to find two num
bers whose sum makes a given number, and whose difference
;ilso makes a given number, than merely to seek two numbers
whose sum makes ten, and whose difference makes six. For
if I proceed in this second problem according to the method
of numerical algebra, mixed with the literal (specieuse), the
calculation will be as follows: a -f b = 10, and a — & = <>;
of wliicli by adding together the right side to the right, and
the left side to the left, I produce the result, a + 6 + a — h =
10-f (>, I.e. (since -{- b and —b cancel each other) '2 a = 10
or (/ = (S. Subtracting the right side from the right, and the
left from the left (since to take a\vay a — b is to add — a + />)
I produce the result a + b — a -f b = 10 — 6. i.e. 26 = 4 or
ft = 2. Thus, I shall in truth have the a and b I ask for,
which are 8 and 2, which satisfy the problem, i.e. whose sum
is 10 and whose difference is 0: but T have not thereby the
general method for any other numbers, which we might wish
468 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
or be able to put in the place of 10 or 6, a method which I
p-ould, however, find with the same facility as these two num
bers 8 and 2, by putting x and v in the place of the numbers
10 and 6. For proceeding the same as before we shall have
a + b + a — b = x + v, i.e. 2a = x + voi'a = %x + v, and we
•shall also have a -f b — a -f b = x — v, i.e. 2b = x — v or b =
ix — v. This calculation gives this theorem or general canon,
that when two numbers are required whose sum and differ
ence are given, you have only to take as the greater of the
required numbers, half of the sum made from the given sum
and difference 5 and for the less of the required numbers, half
of the difference between the given sum and difference. You
see also that I might have dispensed with the letters, if I
had treated the numbers as letters, i.e. if instead of putting
2 a = 16 and 2 b = 4, I had written 2 a = 10 + 6 and 2 b = 10 - 6,
which would have given me a = -J (10 + 6) and b = % (10 — 6).
Thus, in the particular calculation itself 1 should have had the
general calculation, taking these symbols 10 and 6 as general
numbers, as if they were the letters x and v; in order to have
a truth or method more general, and taking these same charac
ters 10 and 6 also for the numbers they ordinarily signify, I
shall have a sensible example which may serve, indeed, as a
proof. And as Vieta l has substituted letters for numbers for
the sake of greater generality, I have desired to reintroduce
the numerical characters, since they are more serviceable
in algebra (specieuse) even than the letters. I have found this
of much use in large calculations for avoiding errors and even
1 Francois Viete, 1540-1603, better known by the Latin form of his name,
Vieta, was a distinguished French mathematician, who is often regarded as
the founder of modern algebra, because of his introduction of the general use
of letters as symbols of undetermined, and therefore general, quantities, thus
opening up the way for the higher mathematical analysis, afterwards carried
on by Descartes and others. To him is also due the invention of the different
simple transformations now used in the solution of equations, such as adding
to or subtracting from the members of an equation the same quantity, or mul
tiplying or dividing them by the same quantity. He first enounced the princi
ple of homogeneity or the principle that all the quantities in an equation should
be of one kind, — lines, surfaces, solids, or supersolids, — a principle which, after
three centuries of controversy, has now been adopted generally by mathemati
cians. His various mathematical writings, which, being a man of wealth, he
printed at his own expense and distributed among the scholars of Europe,
were collected and edited by F. van Schooten, Professor of Mathematics at
Leyden, aided by J. Golius and Mersenne, and published under the title of
Opera mathematica, Leyden, 1646, 1 vol., fol. — TR.
CH. vn] ON HUMAN UNDERSTANDING 409
in the application of proofs, such as the casting away of the
nines in the midst of the computation without waiting for the
result, when there are only numbers instead of letters; which
may often be when you employ skill in the positions, so that
the suppositions are found true in the particular case, besides
the use there is of seeing the connections and orders which
the letters alone cannot always make the mind discern so well,
as I have elsewhere shown, after I found that the good char
acteristic is one of the greatest aids of the human mind.
§ 7. Ph. As for real existence .which I had counted as the
fourth species of existence which may be noticed in ideas, it
can furnish us no axiom, for we have not indeed a demonstra
tive knowledge of beings outside us, God alone excepted.
Th. We can always say that this proposition / exist, is
of the highest evidence, being a proposition which cannot be
proved by any other, or rather an immediate truth. And to
say / think, therefore I am, is not properly to prove existence
by thought, since to think and to be thinking is the same thing;
and to say, I am thinking, is already to say, / am. You can,
however, exclude this proposition from the number of the axi
oms with some reason, for it is a proposition of fact, based
upon an immediate experience, and it is not a necessary prop
osition, whose necessity is seen in the immediate agreement of
ideas. On the contrary, it is only God who sees how these
two terms, /and existence are united, i.e. why I exist. 13ut if
the axiom is taken more generally as an immediate or non-
provable truth, we may say that this proposition, / am, is an
axiom, and in every case we may be assured that it is & primi
tive truth, or rather unum ex primis cognitis inter terminos com-
plexos, i.e. that it is one of the first known statements which
is understood in the natural order of our knowledge, for it
may be that a man has never thought expressly of forming
this proposition, which, however, is innate to him.
§ 8. Ph. [I have always believed that the axioms have little
influence upon the other parts of our knowledge. But you
have disabused me, since you have indeed shown an important
use of identical propositions. Suffer me, however, sir, to set
before you still what I have in mind upon this article, for
your explanations may also serve to make others return from
their error.] § 8. It is a celebrated rule in the schools that
470 LKJBMTZ'iS CKITiqUK OF LOCKK [I-.K.'IV
all reasoning comes from things already known and admitted,
ex praecognitis et praeconcessis. This rule seems to cause these
maxims to be regarded as truths known to the mind before
the others, and the other parts of our knowledge as truths
dependent upon the axioms. § 9. [I think I have shown
(Book I., chap. 1) that these axioms are not the first known,
the child knowing much sooner that the rod which I show him
is not the sugar he has tasted, than all the axioms you please.
But you- have distinguished between particular knowledge or
experiences of facts and the principles of a universal and
necessary knowledge (and herein I admit that it is necessary
to recur to axioms) as also between the natural and accidental
order].
Th. I have also added that in the natural order the state
ment, that a thing is what it is, is prior to the statement that
it is not another; for the question here does not concern the
history of our discoveries, which is different in different men.
but the connection and natural order of truths, which is
always the same.1 But your remark, viz. : that what the child
sees is only a fact, deserves still more reflection; for the expe-
riences of the senses do not give truths absolutely certain (us
you have often yourself, sir, observed not long since), nor are
they exempt from all danger of illusion. For if it is allow
able to make fictions metaphysically possible, sugar might
imperceptibly be changed into a rod, in order to punish the
child who has Ijeen naughty, as water is changed into wine
with us on Christmas eve, if it has been well prepared (/>/.'>/•/-
gene}.'2 But in all cases the pain (you will say) that the rod
inflicts will never be the pleasure the sugar gives. I reply that
the child will take it into his head as late to make an express
proposition about this, as to notice this axiom, that you can-
1 Leibnitz here calls attention to a very important distinction, viz. : the dis
tinction between the historical and the natural or logical order of our knowl
edge. The genesis of our knowledge, its gradual rise in the course of our lives,
is always a matter of individual experience, the experience of no two indi
viduals being precisely alike ; while the natural or logical order and connec
tion of truths, being grounded in reason, is always the same for all. Leibnit/'s
remark further suggests that the origin of a principle or truth is not its
justification, a common fallacy in much of the investigation of the present
day, and that the ultimate criteria of truth are philosophical, not historical.
' '/'. Howne. Mt't«j-ihi/xi<'x. pp. !."> m/,. New York: Harper and Bros., 1882. — Tu.
'J Duncan. I'/iilnn. l\'fr*. <>/ L<'ihi/it\. p. :;.~>4, translates: " ivctitied." — Tu.
vn] OX HUMAN UNDERSTANDING 471
i']ot truly say that what is is not at the same time, although
lie can very well perceive the difference of the pleasure and
the pain, as well as the difference between perceiving and not
perceiving.
§ .10. Ph. There are, however, a number of other truths as
self-evident as these maxims. For example, that one and two
are equal to three, is as evident a proposition as that axiom
which states: that the whole is equal to the sum of all its parts.
Th. You appear to have forgotten, sir, that I have shown
you more than once that the statement one and two is three is
only the definition of the term three, so that to say that one
and two is equal to three, is to say that a thing is equal to
itself. As for this axiom, that the u-hole is equal to the s»m of
all its parts, Euclid makes no express use of it. This axiom
also needs limitation, for it must be added that these parts
must not themselves have a common part, for seven and eight
are parts of twelve, but they make more than twelve. The
bust and the trunk taken together are more than the man, in
that the thorax is common to them both. I3ut Euclid says.
that the whole is greater than its part, a statement which is
wholly trustworthy. And the statement that the body is
greater than the trunk, differs from the axiom of Euclid only
in this, that this axiom is limited to' what is exactly necessary :
but in exemplifying it and clothing the body you make the
intelligible become also sensible, for the statement that a given
whole is larger than a given part, is in fact the proposition
that a whole is larger than its part, but the features of which
are embellished with some coloring or addition: it is as if he
who says A B says A. Thus it is not necessary here to oppose
the axiom and the example as different truths in this regard,
but to consider the axiom as embodied in the example and
rendering it true. It is a different matter, if the evidence is
not observed in the example itself, and when the affirmation
of the example is a consequence, and not merely a sitbftnmp-
tion of the universal proposition, as may occur indeed in the
case of the axioms.
Ph. Oar clever author says here: I should like to ask those
gentlemen who maintain that all other knowledge (not of fact)
depends upon general principles innate and self-evident, what
principle thev need to prove that two and two ft re four? for
472 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
we know (according to him) the truth of this kind of proposi
tions without recourse to any proof. What do you say about
it, sir?
Th. I say that I was 'awaiting you there well prepared.
That two and two are four is not a truth at once immediate,
supposing that four Dignifies three and one. We can then
demonstrate it, and in this way : —
Definitions. — (1) Two is one and one.
(2) Three is two and one.
(3) Four is three and one.
Axiom. — Putting equal things in their place, the equality remains.
Demonstration. — 2 and 2 is 2 and 1 and 1 (by clef. 1) 2 + 2
2 and 1 and 1 is 3 and 1 (by def. 2) 2 + 1 -f 1
3 and 1 is 4 (by def. 3) 3 + 1
4
Then (by the axiom) 2 and 2 is 4. Which was to be demonstrated.
I might, instead of saying that 2 and 2 is 2 and 1 and 1, say
that 2 and 2 is equal to 2 and 1 and 1, and thus with the
others. But it may be understood throughout in order to
shorten the process; and that, in virtue of another axiom
which states that a thing is equal to itself, or that what is
the same, is equal.
Ph. [This demonstration, as little necessary as it is in rela
tion to its too well known conclusion, serves to show how
truths depend on definitions and axioms. Thus I foresee what
reply you will make to many objections that are made against
the use of axioms. You object that there will be an innu
merable multitude of principles ; but this is when you reckon
among the principles the corollaries which follow from the
definitions by the aid of some axiom. And since the defini
tions or ideas are innumerable, so also will the principles be
in this sense, supposing also with you that the undemonstra-
ble principles are the identical axioms. They become innu
merable also by exemplification, but at bottom you can reckon
A is A and B is B as one and the same principle differently
clothed.
Th. Further, this difference of degrees in the evidence
makes me disagree with your distinguished author that all
CH. vn] ON HUMAN UNDERSTANDING 473
these truths called principles and which pass as self-evident,
because they are so near the indemonstrable primitive ax
ioms, are entirely independent and incapable of receiving the
one from the other any light or proof. For they may always
be reduced either to axioms, themselves, or to other truths
nearer the axioms, as this truth, that two and two make four,
has shown you. And I just told you how Koberval diminished
the number of Euclid's axioms, by sometimes reducing one to
another.
§ 11. Ph. This judicious writer, who has furnished an occa
sion for our conferences, agrees that maxims have their use,
but he believes that it is rather that of closing the mouth of
the obstinate, than of establishing the sciences. I should be
very glad, said he, if you would show me some one of these
sciences built upon these general axioms which cannot be
shown to be sustained as well without axioms.
Tli. Geometry is, without doubt, one of these sciences.
Euclid expressly employs axioms in demonstration, and this
axiom : that two homogeneous magnitudes are equal when one is
neither larger nor smaller than the other, is the basis of the
demonstrations of Euclid and Archimedes respecting the size
of curvilinears. Archimedes employed axioms of which Euclid
had no need; for example, of two lines, each of which is con
cave always on the same side, that which encloses the other is
the greater. We cannot also dispense with the identical ax
ioms in geometry, as, for example, the principle of contradic
tion, or the demonstrations which lead to the impossible.
And as for the other axioms, which are demonstrable, we may
dispense with them, absolutely speaking, and draw conclu
sions immediately from the identicals and from the defini
tions; but the prolixity of the demonstrations, and the end
less repetitions into which you would then fall, would cause
a horrible confusion, if it were always necessary to begin ab
ovo ; while by assuming the mean propositions, already
proved, we easily pass much farther. This assumption of
truths already known is useful, especially as regards the ax
ioms, for they recur so often that geometers are compelled to
make use of them constantly without citing them ; so that we
should be mistaken in thinking that they are not there, because
we do not perhaps always see them quoted in the margin.
474 LEIBNITZ'S CRITIQUE OF LOCKE [BK. ir
Ph. But he objects to the example from theology. For the
knowledge of this holy religion came to us from revelation
(says our author), and without this aid the maxims would
never have been able to make us know it. The light comes to
us then from the things themselves, or immediately from the
infallible veracity of God.
Th. It is as if I said, medicine is based upon experience,
reason then is of no use therein. Christian theology, which
is the true medicine for souls, is based upon revelation which
corresponds to experience ; but to make of it a perfect body,
we must unite therewith natural theology, which is drawn
from the axioms of eternal reason. Is not this principle
indeed that veracity is an attribute of God, upon which you
acknowledge that the certainty of revelation is based, a maxim
taken from natural theology?1
Pli. Our author wishes to distinguish between the means of
acquiring knowledge and of teaching it, or rather between
teaching and communicating. After schools had been erected
and professors established to teach the sciences that others had
found out, these professors availed themselves of these max
ims in order to impress the sciences upon the minds of their
scholars, and to convince them by means of the axioms of cer
tain particular truths; while the particular truths have served
the first discoverers in finding the truth without the general
maxims.
Th. I wish that this pretended procedure had been justified
for us by examples of some particular truths. But rightly
considering things, we shall not find it practised in the estab
lishment of the sciences. And if the discoverer finds only a
particular truth, he is only half a discoverer. If Pythagoras'2
1 Locke, without discussing its possibility or its method, assumes a special
source of religion in an immediate revelation of God to the soul of man, and
rests the truth of this revelation upon the " unerring veracity" of God. Of.
Philoft. Wks., Vol. 2, p. 209, Bonn's ed. Leibnitz, who elsewhere discusses to
a certain extent both the possibility and the method of revelation, and admits
its possibility, and also its actuality, especially as regards those things which
are beyond the limits of our finite experience, emphasizes the rational element
in theology by calling attention to the fact that revelation presupposes a nat
ural idea of God, philosophically derived and including the attribute of verac
ity, to which it may appeal and by which its character and claims to authority
must be judged. — TR.
- Cf. ante, p. 379. note 1. On his life and philosophy, cf. Zeller, Philon. d.
frriech., 5th ed., Vol. 1, pp. 296 sq. For his mathematical work, cf. G. J.
CH. vn] ON HUMAN UNDERSTANDING 47")
had only observed that the triangle whose sides are 3, 4, 5, has
the property of the equality of the square on the hypothenuse
with those on the sides (i.e. that 9 + 16* = 25), would he on
that account have been the discoverer of this great truth which
includes all right-angled triangles, and which has passed into
a maxim with the geometers? It is true that often an exam
ple, seen by chance, serves as the occasion which suggests to a
clever man the search for general truth, but it is still very
often no easy matter to find it; besides, this path of discovery
is not the best nor the most employed by those who proceed in
an orderly and methodical way, and they make use of it only
upon the occasions when better methods fall short. In the
same way, some have thought that Archimedes found the
quadrature of the parabola by weighing a piece of wood cut
parabolically, and that this particular experiment caused him
to discover the general truth; but those who know the pene
tration of this great man see clearly that he had no need of
such an aid. Moreover, if this empirical way of particular
truths had been the occasion of all the discoveries, it would
not have been sufficient to give them; and the discoverers
themselves have been delighted with observing the maxims
and the general truths if they have been able to attain them,
otherwise their discoveries would have been very imperfect.
All that may then be attributed to the schools and to the pro
fessors, is that they have collected and arranged the maxims
and other general truths: and would God they had done so
still more and with more care and choice, the sciences would
not be found so scattered and so confused. For the rest I
admit, that there is often some difference between the method
we use in teaching the sciences and that which has produced
their discovery : but this is not the point in question. Some
times, as I have already observed, chance has given occasion
for discovery. If we had noticed these occasions, and had
preserved the memory of them for posterity (which would
have been very useful), this detail would have been a very con
siderable part of the history of the arts, but it would not have
Allmaii. Greek Geometry from Thalex to Euclid, Dublin, 1880. and, by the
same author, Pythagorean Geometry, being the mathematical part of the
article "Pythagoras" in the Encydop. Brit., Oth ed., Vol. 20, pp. 1411-140
(Amor, ed.). — TR.
476 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
been proper to make systems of them. Sometimes also dis
coverers have proceeded rationally to the truth, but by ex
tended circuits. I find that in matters of importance authors
would have rendered service to the public, if . they had been
willing sincerely to indicate in their writings the traces of
their experiments ; but if the system of science should be built
upon that foundation, it would be as if in a finished house you
wished to preserve all the apparatus which1 the architect re*
quired in building it. Good methods of teaching are all such
that by their means science could certainly have been discov
ered; and then if they are not empirical, i'.e. if the truths are
taught by reasons or by proofs drawn from ideas, it will always
be by axioms, theorems, canons, and such other general propo
sitions. The case is different when the truths are aphorisms
like those of Hippocrates,2 i.e. truths of fact either general, or
1 Gerhard t reads "done," manifestly a manuscript or a typographical error.
Erdmann, Jacques, and Janet read "dont," which the translation follows. —
TR.
2 Hippocrates of Cos, 460-375 B.C., the " Father of Medicine," was the first
to base the practice of medicine ofl the observation of nature and the principles
of an inductive philosophy. Though descended from a family of priest-physi
cians, he put aside all its traditions and prejudices, gave himself up to the
study of the natural history of disease in the living subject, and treated it
always as subject to natural laws. He placed especial emphasis on sympto-
mology and dietetics. The two chief modern critical editions of his writings, or
those ascribed to him, are E. Littre, CEuvres completes d' Hippocrate , 10 vols.,
Paris, 1830-61, and F. Z. Ermerins, Hippocratis et aliorum medicorum veterum
reliquiae, 3 vols., Utrecht, 1859-64. The 'A^opt<r/u.ot — Aphorisms — are accepted
as absolutely genuine by Littre, but rejected as spurious by Ermerins. The
Greek text with French trans, is found in Littre, op. cit., Vol. 4, pp. 396 sq. ;
with Latin trans., in Ermerins, op. cit., Vol. 1, pp. 397 sq. For an English
translation, cf. F. Adams, Genuine Wks. of Hippocrates (Sydenham Soc.),2
vols., London, 1849, Vol. 2, p. 685.
In this connection I may add that Professor Schaarschmidt of Bonn Uni
versity has kindly informed me that the phrase O-V/JLTTVOLO. navra cited by Leibnitz
from Hippocrates, cf. ante, p. 48 (ad fin.} is to be found in the iiepi TPO</>TJS, § 23,
Littre', (Euvres d' Hippocrate, Vol. 9, p. 106, where it runs thus: Suppoia n-ia,
^v^Ttvoia. /uu'a, gviJ.Tra.Oea. iravva. • K.r.A. Professor Schaarschmidt thinks that Leib
nitz probably read: ^v^rvoia. n6.vra, — conspirantia omnia, — omitting /aia and
£vnTTa9ea, and took fu/oLTri'oia for an adjective, while it is in the text a substan
tive meaning concordance, — conspiratio, — a usage which sometimes occurs,
cA Stephanus, Thesau. Ling. Grsec., Vol. 3, p. 416, C; or that he quoted
from memory, as he often does. Su/a^ov? — conspirans — as an epithet of the
universe occurs in Plutarch, De fato, 2, 574, E: TO <f>v<rei Si<H/<eur0ai rovSe rov
KCHTH.OV, vvfjurvow, ical o-v/u.7ra0fj, avTbv avrw ovra, i.e. " that the world is governed
by Nature, and that it conspires, consents, and is compatible with itself."
Plutarch's Morals, Eng. trans., by several hands, corrected and revised by
W. W. Goodwin, Ph.D., Vol. 5, p. 308, Boston : Little, Brown & Co., 1870. — TR.
CH. vn] ON HUMAN UNDERSTANDING 477
at least true most frequently, learned by observation or based
on experience, and for which there are no reasons immedi
ately convincing. But the question here is not about this,
for these truths are not known by the connection of ideas.
Ph. Here is the manner in which our ingenious author con
ceives that the need of maxims has been introduced. The
schools having established disputation as the touchstone of the
ability of people, they adjudged the victory to the one who
holds the field of battle and speaks the last word. But in
order to furnish means of convincing the obstinate, it was
necessary to establish maxims.
Th. The schools of philosophy had done better, no doubt,
to unite practice with theory, as do the schools of medicine,
chemistry, and mathematics ; and to give the prize to the one
who had done the best, especially in ethics, rather than to the
one who had spoken the best. Yet as there are matters in
which discourse itself is an effect and sometimes the sole
effect and masterpiece which can make known the ability of
a man, as in metaphysical matters, we have had reason on
some occasions to judge of the ability of people by their suc
cess in the conferences. We know, indeed, that at the begin
ning of the Reformation the Protestants challenged their
adversaries to come to colloquies and discussions, and some
times upon the success of these discussions the public con
cluded for the reform. We know, also, how much the art of
speaking and of giving birth and force to reasons, and, if it
may be so called, the art of discussion, can accomplish in a
council of state and of war, a court of justice, a medical con
sultation, and even in a conversation. And we are obliged to
recur to this means and to content ourselves with words
instead of acts on those occasions, for this very reason that
the question then concerns an event or future fact where it
would be too late to learn the truth by the effect. Thus the
art of discussion or of contending by reasons (whereby I here
understand the quotation of authorities and examples) is very
great and very important ; but unfortunately it is very badly
managed, and for this reason also often reaches no conclusion
or a bad one. It is for this reason that I have more than
once intended to remark upon the colloquies of theologians,
accounts of whom we have, in order to show the defects which
478 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
may be noticed in them and the remedies that might be em
ployed therefor. In consultations upon business, if those who
have the most power have not a very solid mind, authority or
eloquence prevail ordinarily, although they are banded against
the truth. In a word, the art of conferring and discussing
would need to be entirely remodelled. As for the advantage
of the one who has the last word, it is almost wholly in free
conversations; for in councils suffrages or votes go by order,
whether they begin or finish with the last in rank. It is true
that it ordinarily belongs to the president to begin and end,
i.e. to propose and decide; but he decides according to the
plurality of the votes. In academic discussions it is the
respondent or maintainant (of the thesis) who speaks last, and
the tield of battle abides with him, almost always by an
established custom. It is a question of testing him, not of
confounding him; otherwise it would be treating him as an
enemy. In reality, there is almost no question of truth on
these occasions : indeed, opposite theses are maintained at
different times in the same chair. The hall of the Sorbonne
Avas shown to Casaubon,1 and they said to him: this is the
place where they have disputed for so many centuries; he
replied, to what conclusion have they come?
Ph. The wish was, however, to prevent the dispute from
going on to infinity, and to furnish means of deciding between
two equally expert combatants, in order that the dispute
enter not upon an infinite series of syllogisms. This means
was the introduction of certain general propositions, the
larger part self-evident, and which being of such a nature as
to be received by all men with entire consent, were to be
regarded as general measures of truth, and to hold the place of
]>rinciples (when the disputants had posited no others), beyond
which none could go, and to which both sides were obliged to
hold. Thus these maxims having received the name of .prin
ciples which could be denied in the dispute, and which ended
the question, they were taken erroneously (according to my
author) as the sources of knowledge and the foundations of
the sciences.
1 Isaac Casaubon, 15r>9-l(>14, a great classical scholar and editor", who had
the reputation of being, next to Scaliger, the most learned man of his age.
Leibnitz also relates this anecdote in his letter to Thomas Burnett, Feb. 1-1 J,
Hi!*:, Gerhardt. :'., 1<)2. Dutens, f>, 24"». — TR.
oi. vii] ON HUMAN UNDERSTANDING
Th. Would to God we had made use of them in this way
in the discussions, there would be nothing to say in reply, for
\ve should decide something. And what better thing could
we do than to reduce controversy, i.e. contested truths to
truths evident and incontestable? would not that be to estab
lish them in a demonstrative fashion? And who can doubt
that these principles, which would end disputes by establish
ing truth, would not be at the same time sources of knowledge?
For, provided the reasoning is good, it matters not whether
it is carried on silently in one's study, or exposed for sale
publicly in a professor's chair. And even if these principles
were assumptions rather than axioms, taking the assumptions
not as Euclid, but as Aristotle, i.e. as suppositions which
must be admitted while waiting opportunity to prove them,
these principles would always have this use, that by means
«>f them all the other questions would be reduced to a small
number of propositions. Thus I am the most surprised of
anybody to see a praiseworthy thing blamed by I know not
what prepossession, to which we clearly see by the example
of your author the most clever men are susceptible through
want of attention. Unfortunately they do an entirely differ
ent thing in academic, disputes. Instead of establishing gen
eral axioms, they do all they can to weaken them by vain and
little understood distinctions, and it pleases them to employ
certain philosophical rules, of which there are large books
completely full, but which are little certain and little deter
mined and which they have the pleasure of eluding while dis
tinguishing them. This is not the way to end the disputes,
but to render them infinite, and finally to wear out the
adversary. It is as if we put him in a dark place, where we
strike at random and no one can judge the blows. This
invention is admirable for the maintainants (Respondentex}
who are engaged in maintaining certain theses. It is a buck
ler of Vulcan which renders them invulnerable; it is Orrf
((<tlwt. Pluto's helmet, which renders them invisible. They
must be very unskilful or very unfortunate if they can be
caught with that. It is true there are some rales which have
exceptions, especially in questions into which many circum
stances enter, as in jurisprudence. But to render their use
sure these exceptions must be determined in number and
480 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
sense so far as possible; and then it may be that the excep
tion itself has its sub -exceptions, i.e. its replications, and that
the replication has its duplications, etc., but at the end of the
reckoning, all these exceptions and sub-exceptions, clearly de
termined, and joined with the rule, must achieve universality.
Of this jurisprudence furnishes very remarkable examples.
But if these kinds of rules, loaded with exceptions and sub-
exceptions, should enter into academic disputes, it would
always be necessary to dispute pen in hand, holding as a
protocol what is said by both sides. And this would be more
necessary elsewhere, in disputing constantly pro forma by
means of many syllogisms, mixed from time to time with dis
tinctions, which the best memory in the world must confound.
But we are not kept from giving ourselves this trouble, from
pushing sufficiently the formal syllogisms and from registering
them, in order to discover the truth when it is without recom
pense, and we should not indeed succeed therein, if we wished,
unless the distinctions are excluded or better regulated.
Ph. It is, however, true, as our author observes, that the
scholastic method having been introduced also into conversa
tions outside the schools, in order to shut the mouths of
cavillers, has produced a bad effect. For, provided we have
mediate ideas, we may have the connection without the aid of
the maxims and' before they have been produced, and that
would be sufficient for sincere and tractable people. But the
method of the schools having authorized and encouraged men
in opposing and resisting evident truths until they are reduced
to contradict themselves or to fight established principles, it
is no wonder that in ordinary conversation they are not
ashamed to do what in the schools is a subject of glory and
counted a virtue. The author adds that reasonable people,
among the rest of the world, who are not yet corrupted by
education, will find it very difficult to believe that such a
method has ever been followed by persons who make a pro
fession of loving truth, and who pass their lives in studying
religion or nature. I shall not inquire here (says he) how
this method of instructing is fitted to turn away the minds of
young people from the love of and sincere search for the
truth, or rather to make them doubt if there really is any
truth in the world, or at least any which deserves their
CH. vn] ON HUMAN UNDERSTANDING 481
adherence. But what I strongly think (he adds) is this, that
excepting those places which have admitted the Peripatetic
philosophy into their schools, where it has reigned many cen
turies without teaching the world anything but the art of dis
putation, these maxims are nowhere regarded as the foundations
of the sciences nor as important aids to advancement in the
knowledge of things.
Th. Your clever author will have it that the schools alone
have been led to form maxims ; but it is the general and very
rational instinct of the human race. You can infer this from
the proverbs which are in use among all nations, and which
are usually only maxims which the public acknowledge. But
when persons of judgment make a statement which appears to
us contrary to the truth, we must do them the justice to sus
pect that there is a greater defect in their expressions than
in their sentiments : a procedure confirmed here in our author,
of whose motive animating him against the maxims, I begin
to catch a glimpse. Cavilling, as well as the desire to be con
vinced in order to yield, exists as really in ordinary discourse,
where there is no question of exercise, as in the schools; else
where most frequently they have the better grace to suppress
the. majors which are understood, and to be contented with
enthymemes, and indeed without forming premises it is suffi
cient often to use the simple medius terminus or mediate idea,
the mind understanding sufficiently its connection without ex
pressing it.1 And this is satisfactory when this bond is incon
testable ; but you, sir, will also agree with me that often we
go too fast in assumption, and that paralogisms arise so that
it would very often be better to have regard for certainty,
in expressing ourselves, than to prefer thereto brevity and
elegance. But the prejudice of your author against maxims
1 Ordinarily in argumentation we omit one of the premises, usually the
major, as easily understood and too clearly manifest to require statement.
Sometimes, but less commonly, we omit the minor premise, and occasionally
the conclusion, as in epigrams and other forms of wit, the whole point of
which very often consists in making apparent the unexpressed truth. Leib
nitz emphasizes the sufficiency of the middle term — medius terminus — or
mediate idea, because through it, the common term in the premises expressing
the particular reason in the given case, the conclusion is reached, whence the
middle term is sometimes called the argument. The mind having grasped the
particular reason expressed in this term, can easily supply the rest of the argu
ment, and, if necessary, state it in due syllogistic form. — TR.
2 i
482 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
made him reject altogether their utility for the establishment
of the truth, and goes as far as to make them accomplices with
disorders in conversation. It is true that young p'eople
accustomed to academic exercises in which they are occupied
a little too much with exercise and not enough in drawing
from the exercise the greatest fruit it should have, viz. :
knowledge, have some difficulty in emancipating themselves
therefrom in the world. And one of their cavillings is not to
wish to yield themselves to the truth save when it has been
rendered entirely palpable to them, though sincerity and
indeed civility should compel them not to wait for these ex
tremes, which make them disagreeable and give a bad opinion of
them. It must also be admitted that it is a vice with which
men of letters are often found infected. But the fault is not
in wishing to reduce truths to maxims, but in wishing to do
it unseasonably and needlessly, for the human mind sees much
at a glance, and it is to restrain it that we wish to compel it
to stop at every step it takes and to express all that it thinks.
It is precisely as if when making his account with a merchant
or host one should compel him to reckon the whole with the
fingers in order to be more certain of it. And to make that
demand he must be either stupid or capricious. In fact.
sometimes we find that Petronius had reason for saying
adolescentex hi xcholis titultissimos fieri,1 that }^oung people
sometimes become stupid and even harebrained in places.
which ought to be schools of wisdom; corruptio optimi pessima.'2
But still oftener they become vain, blundering, and confused,
whimsical, troublesome, and that often depends on the dis
position of their masters. For the rest, I find that there are
far greater faults in conversation than that of demanding too
much clearness. For usually we fall into the opposite vice
and neither give nor ask for enough of it. If the one is
troublesome, the other is hurtful and dangerous.
1 Petronius, Satt/ricon, chap. 1: " Et ideo ego adolescentulos existimo in
scholis stultissimos fieri, quia nihil ex iis, qme in usu habemns, ant audiunt,
ant vident," etc. — TR.
- The phrase is not found in any classical author. It was perhaps suggested
by Aristotle, Politics, A, 2, 1289a, .'59: ai'dyxri yap rrjr nev TTJS Trpwrrj? Kal 9ei.ordT^
jVoAiTeuxs] na.pfK8a<ru> eiVai xeipi'o-Tqr, thus translated by Jowett, The Politic*
of Aristotle, Vol. 1, p. 109, Oxford : Clarendon Press. 1885 : " That which is the
perversion of the first and most divine [government] is necessarily the worst."
CH. vn] ON HUMAN UNDERSTANDING
§ 12. Ph. The use of maxims is sometimes also, when
attached to false notions, vague and uncertain; for then the
maxims serve to confirm us in our errors, and even to prove
contradictions. For example, he who with Descartes 1 forms
an idea of what he calls body, as of a thing which is nothing
but extension, may demonstrate easily by this maxim what As,
is, that there is no vacuum, i.e. space without body. For he
knows his own idea, he knows that it is what it is and not
another idea; thus extension, body, and space being with him
three words signifying one and the same thing, it is also as
true for him to say, that space is body, as to say that body is
body. $ 13. Hut another for whom body signifies a solid
extension, will conclude in the same way that to say: that
space is not a body is as certain as any proposition we can
prove by this maxim: it is impossible for a thing to be and not
to be at the same time.
77*. The bad use of maxims should not cause their general
use to be censured; all truths are liable to this disadvantage,
that, by uniting them with falsehoods, false or even contradic
tory conclusions may be drawn. And in this example there
is but little need of these identical axioms to which is im
puted the cause of the error and contradiction. This would
be seen if the argument of those who concluded from their
definitions, that space is body, or that space is not body,
Avere reduced to form. There is, indeed, something exces
sive in this inference: body is extended and solid, then exten
sion, i.e. the extended is not body, and extension is not a
corporeal thing; for I have already remarked that there are
superfluous expressions of ideas, or those which do not mul
tiply things, as if some one said, by triquetrum I mean a
trilateral triangle, and concluded therefrom that every trilat
eral is not a triangle. Thus a Cartesian might say that the
idea of a solid extension is of this same nature, i.e. that it is
superfluous; as in reality, taking extension as something sub
stantial, every extension will be solid, or rather every exten
sion will be corporeal. As for the vacuum, a Cartesian will be
right in concluding from his .idea or form of idea that there is
none, supposing his idea to be valid; but another will not be
1 Cf. Pri,iri,>. I'hilo*.. II., §§ 1, 4, 11, Veitch's trans., pp. 2:52. 237, 8th e.l..
, 1S81. — TR.
484 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
right in concluding at once from his form that there may be a
vacuum, as in reality, although I am not for the Cartesian
view, I nevertheless think there is no vacuum,1 and I find
that in this example a worse use is made of ideas than of
maxims.
§ 15. Ph. It seems at least that from such use as you would
make of maxims in verbal propositions they cannot give us
the least knowledge of substances existing outside us.
Th. I am altogether of another opinion. For example, this
maxim that nature proceeds by the shortest paths, or at least
by the most definite, suffices alone to give a reason for nearly
the whole of optics, catoptric and dioptric, i.e. of what takes
place outside us in the action of light, as I have formerly
shown 2 and Molyneux has strongly approved in his Dioptric,
which is a very excellent book.3
Ph. It is maintained, however, that when use is made of
identical principles to prove propositions in which there are
words signifying complex ideas as man or virtue, their use is
extremely dangerous, and invites men to regard or receive
falsehood as manifest truth. And this is because men think
that when the same terms are retained the propositions re
volve about the same things, although the ideas which these
terms signify are different; so that men taking the words for
the things, as they usually do, these maxims commonly serve
to prove contradictory propositions.
Th. How unjust to blame the poor maxims for that which
should be imputed to the bad use of terms and to their equiv
ocations. By the same reasoning you will blame the syllo
gisms because they conclude badly when the terms are equiv
ocal. But the syllogism is innocent, because in reality there
are then four terms contrary to the rules of the syllogism.
By the same reasoning you would also blame the calculations
of arithmeticians, or of algebraists, because by putting Xfor V
or by taking a for b by inadvertence, they draw therefrom
false and contradictory conclusions.
1 Cf. ante, p. 16, and New Essays, Bk. II., chap. 4, ante, pp. 125-127; also
Descartes, Princip. Philos., II., §§ 16 sq., Veitch's trans., pp. 241 sq.— TR.
2 Leibnitz probably refers to his article Unicum opticss catoptrics^ et di-
optricsB principium, published in the " Acta Erud. Lips.," June, 1682, pp. 185-
190, and found in Dutens, 3, 145-150. — TR.
3 Cf. ante, p. 138, note 1. Molyneux's Dioptrica nova was for a long time
the chief work on Optics. — TR.
CH. vn] ON HUMAN UNDERSTANDING 485
§ 19. Ph. I should think at least that maxims are of little
use when we have clear and distinct ideas ; and others will
have it indeed that then they are absolutely of no use, and
maintain that any one who in these instances cannot discern
truth and falsehood without these kinds of maxims, will not
be able to do so by their agency; and our author (§§ 16, 17)
shows indeed that they are of no use in deciding whether such
a one is a man or not.
Th. If the truths are very simple and evident, and closely
approaching the identicals and the definitions, there is but
little need of expressly employing maxims to draw from
them these truths, for the mind virtually employs them and
makes its conclusion all at once without intermediate ideas.
But without axioms and theorems already known, mathema
ticians would have much trouble in advancing; for in long
processes of reasoning (consequences}, it is well to stop from
time to time, and to set up, as it were, military columns in
the midst of the road, which will serve furthermore to indi
cate it to others. Otherwise these long roads will be too
inconvenient, and will appear even confused and obscure,
while we are unable to discern anything, or to point out what
place we are in. It is like going to sea without a compass in
a dark night, seeing neither bottom, shore, nor stars ; it is like
travelling in vast moors in which there are neither trees nor
hills nor streams; it is like a linked chain destined for the
measurement of lengths, in which there are some hundreds of
links, perfectly alike, without a distinction of a bead, or of
coarser grains or of larger links or other divisions which
might indicate the feet, fathoms, perches, etc. The mind
which loves unity in multiplicity then joins together some of
the consequences to form from them mediate conclusions, and
this is the use of maxims and theorems. By this means there
is more pleasure, more light, more memory, more application
and less repetition. If some analyst in calculating should
choose not to assume these two geometrical maxims, that the
square on the hypothenuse is equal to the two squares of the
sides about the right angle, and that the corresponding sides
of similar triangles are proportional, thinking that, because
we have the demonstration of these two theorems by the con
nection of the ideas they contain, he can pass them by easily
480 LK1BMT//S CIUTlQrK OF LOCKE [BK. iv
by putting the ideas themselves in their place, he will find
himself far removed from his reckoning. But that you may
not think, sir, that the proper use of these maxims is confined
to the limits of the mathematical sciences alone, you will find
that its use is not less in jurisprudence, and one of the prin
cipal means of rendering it easier, and of looking at its vast
ocean as upon a geographical map, is to reduce a multitude of
particular decisions to more general principles. For exam
ple, you will find that a multitude of laws, of Digests, of
actions or exceptions, of those which are called in factittn.*
depend on this maxim, ue (juin altering danuio fiat locupletior,*
let no one profit by the injury which might happen to an
other, a principle which should, however, be expressed with a
little more precision. It is true that there is a great distinc
tion to be made between the rules of law. I speak of good
ones, and not of certain brocards (brocardica)8 introduced by
the doctors which are vague and obscure: although these rules
also might often become good and useful, if reformed, while
with their infinite distinctions (<•«?/* SHIS fallentiis) they serve
only to confuse. Now good rules are either aphorisms or
maxims, and under maxims 1 include both axioms and theo
rems. If these are aphorisms which are formed by induction
and observation, and not by reason a priori and which clever
people have made after a review of established law, this text
of the jurisconsult Paulus in the title of the Digests, which
speaks of the rules of law, lias place: noii PX regulo. jus sum!,
1 Cf. lH<j,'St.. Lib. XLIV., Tit. VII.. 2r>, Ulpianns. lib. singul. Kegulanini :
"§ 1. — In ffictiun actio dicitur, quails est (exempli gratia) actio qufe datur
patrono ad versus libertuin, a quo contra edict uni prsetoris in jus vocatus
est.'' — TR.
- For a similar expression, <-f. D'njexl., Lib. L., Tit. XVII.. 20<>, Pomponius.
lib. !>, ex variis Lectionibns : "Jure natune requum est. nemiuem cum alterius
detrimento et injuria tieri locupletiorem " ; Dif/est., Lib. XII., Tit. VI. . 14:
also Lib. XXIII. , Tit. III., <i, Pomponius, lib. 14 ad Sabinum, §2: ". . . quia
bono et iequo non conveniat, aut Incrari aliquem cum damno alterius, ant
damnum sentire per alterius lucrum " : Lib. XIV.. Tit. III., 17, § 4, ad tin. — TH.
3 rf. Letter 11, to Kestner, Jan. M, 1711, § 2 (Dutens, 4, Pt. III., 2(i4, also
Kortholt, Leibnit. <jj>ixt. <«l diwrsos, Lips. 17-'>4-1742, '.), 251): " Brocardica
qure vocant, vel sunt ipsa solida juris principia, vel reguhe, quaedam topica^ :
priora necessaria sunt : posteriores utiles 1'orent, si satis examinatse, explica-
tjeque haberentur : pertinent enim fere ad t'acti qiuestionem. artemque conji-
ciendi, ad quam refero etiam interj)retandi artiticium." f'f. also Leibnitx's
Xnra mHJuHlii* ili^finliF iJnrendifjnf JHri^riifiaitifp, Pt. 11.. § L'."), Dutens. 4.
Pt. III., 1S8-1SH. — TR.
ii] ON HUMAN UNDERSTANDING 487
#ed ex jure quod est regulam fieri,1 i.e. we draw rules from a
law already known, in order the better to remember them, but
\ve do not establish the law upon these rules. But there are
fundamental maxims constituting the law itself and forming
actions, exceptions, replications, etc., which, when they are
taught by pure reason, and do not arise from the arbitrary
power of the state, constitute natural law; and such is the
rule of which I have just spoken, which forbids tortious
profit. There are also rules whose exceptions are rare, and
which consequently pass as universal. Such is the rule of the
Institutes of the Emperor Justinian in § '2 of the title Actions,
which declares that when the question concerns corporeal
things, the actor does not possess, except in a single case
which the emperor states is indicated in the Digests; but
he leaves us to search for it. It is true that some read
instead of sane into casn, sane nort nno ; 2 and from one case
von can sometimes make many. Among the physicians the
late Mr. Earner,3 who, in giving us his Prodromus, made us
hope for a new Sennertus,4 or system of medicine accommodated
1 Cf. Digest., Lil>. L., Tit. XVII., 1. Paulas [lib. 1(5 ad Plautium] : " Regula
est, qute rem, quse est, breviter enarrat. Non ut ex regula jus sumatur, sed
ex jure, quod est, regula liat." Gerhardt's text omits the name Paulus, and
his footnote states that there is a gap in the Ms. — TR.
2 Cf. Sandars, Imt. of Justinian, Lib. IV., Tit. VI., De actionibus, § 2, mi
Jin. (p. 431, 8th ed., London, 1888): "Quod genus actionis in eontroversiis
rerum corporalium proditum non est, nam in his is agit qui non possidet: ei
vero qui possidet, non est aetio prodita per quam neget rem actoris esse. Sane
uno casu, qui possidet, nihilominus actoris partes obtinet, sicut in latioribus
Digestorum libris opportunius apparebit." The reading "sane uno casu'' is
adopted and followed by the modern editors. The references to the Digests
are, according to Sandars, Lib. VIII., 5, 2, Lib. XXXIX., 1, 15, ed. Mommsen,
Berlin: Weidmann, 1870, pp. 207, 378. — TR,
3 Jacob Earner, 1(541-1686, a German physician, was professor of chemistry
at Padua, and of philosophy and medicine at Leipzig, and the author or com
piler of a large number of works which give a sufficiently faithful account of
the medicine and especially the chemistry of his time, wholly occupied as it
was in the chimerical search for the philosopher's stone. His Prodromus Xen-
iierti novi, Augustte Vindelicorurn, 1074, 4to, was published as the prospectus
of a proposed, but never completed, work, which, like that of Sennert, should
cover the history of medicine from the earliest times to his own day. — TR.
4 Daniel Sennert, 1572-1(537, a celebrated German physician, was professor
of medicine in the University of Wittemberg from 1(502-1637, and introduced
into its curriculum the teaching of chemistry, in spite of strong and continued
opposition from those who thought it useless. He disputed the doctrine of the
soul held by the Schoolmen, and by maintaining the immateriality of the souls
of juiimals raised against himself many adversaries, among whom was Honora-
488 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
to the new discoveries or views, advances the opinion that the
method which physicians ordinarily observe in their systems
of practice is to explain the art of healing by treating of one
disease after another following the order of the parts of the
body human or other, without having given universal precepts
of practice common to many diseases and symptoms, and that
this involves them in an infinite number of repetitions; so
that we might suppress, in his view, three-quarters of Senner-
tus, and abridge the science infinitely by universal propositions,
and especially by those with which agrees the Ka06\ov Trpurov
of Aristotle,1 i.e. which are reciprocal, or approach thereto.
I think there is reason in advising this method, especially as
regards the precepts wherein medicine is ratiocinative ; but in
proportion as it is empirical, it is not so easy nor so certain
to form universal propositions. Further, there are usually
complications in particular diseases, which form, as it were,
an imitation of substances, so that a disease is like a plant or
an animal, which demands a history by itself, i.e. they are
modes or forms of being with which agrees what we have said
of bodies or substantial things, a quartan 2 fever being as diffi
cult to examine thoroughly as gold or quicksilver. Thus it is
well, without detriment to the universal precepts, to seek in the
tus Fabri, who accused him of blasphemy and impiety, because he had not
seen the bearing of his reasonings. Sennert protested that he had never main
tained the immortality of the souls of animals, but it was a strict consequence
of his principle.
In his Institutions medicse et de origine animarum in brutis, Wittemberg,
1611, 4to, Sennert endeavored to unite for the first time the principles of Galen
(cf. ante, p. 407, note 1) with those of Paracelsus, 1493-1541. His Opera omnia,
ed. novissima, Lugduni, 1676, 6 vols., fol. Sprengel says he was "the most
celebrated of all the conciliators of the seventeenth century," "a man who
united to immense erudition and to a perfect knowledge of the ancients great
credulity, a taste little refined, and a weak judgment.".— TR.
1 Aristotle limited scientific consideration to that which is universally or
for the most part valid. His <a96\ov npurov is the universal in its original and
proper sense, as the essential attribute of individual things in which alone it
has any realization, and whose essence consists in just this realization of the
universal in them. This universal is conceived of as the cause, and as such
becomes the middle term in the syllogism, and constitutes the absolutely essen
tial element in logical demonstration, in the absence of which the reasoning
has no validity. Cf. Wallace, Outlines of the Philos. of Aristotle, 3d ed., §§ 23,
32-34, pp. 47, 64 ; Zeller, Philos. d. Griech. II. 2 [Vol. 4] , 304 sq., 3d ed. ; Prantl,
Gesch. d. Logik, 1, 104 sq., 119 sq. ; Windelband, A Hist, of Philos., trans, by
J. H. Tufts, Ph.D., 133-143. New York: Macmillan & Co., 1893. — TR.
2 I.e. a fever running in periods of four days. — TR.
CH. vn] ON HUMAN UNDERSTANDING 489
different kinds of diseases methods of healing, and remedies
which satisfy many symptoms and complications of causes,
and especially to gather together those which experience has
approved. This Sennertus has not sufficiently done, for com
petent judges have remarked that the compositions of the
receipts he proposes are often made more ex inqenio by
estimate . than authorized by experience, as would be neces
sary if one would be more certain of his case. I think then
that the better course would be to unite these two ways, and
not to complain of repetitions in a matter so delicate and so
important as is medicine, wherein I find that we lack what
we have in too large measure in my view in jurisprudence, i.e.
books of particular cases, and repertories of observations
already made. For I think that a thousandth part of the
books of the jurisconsults would suffice us, but that we would
have none too many in the matter of medicine, if we had thou
sands more of well-detailed observations. The fact is, juris
prudence is wholly based upon reasons in regard to which
nothing is expressly indicated by laws or by customs. For we
can always derive it either from law or, in default of this,
from natural right by means of the reason. The laws of
each country are finished and determined, or may become so;
while in medicine, the principles of experience, i.e. the ob
servations, cannot be too greatly multiplied in order to give
more opportunity to the reason to decipher what nature only
half allows us to know. For the rest, I do not know any one
who employs the axioms in the way that the clever author of
whom you speak does (§§ 16, 17), as if any one, in order to
demonstrate to a child that a negro is a man, availed himself
of the principle what is, is, by saying : a negro has a rational
soul; now the rational soul and man is the same thing, and
consequently if having a rational soul he were not a man, it
would be false that what is, is, or rather one and the same
thing would be or would not be at the same time. For with
out employing these maxims, which are not in season here,
and do not enter directly into the reasoning, as they also do
not advance it in any respect, everybody will be content to
reason thus: a negro has a rational soul, whoever has a
rational soul is a man, therefore the negro is a man. And if
any one assuming that there is no rational soul if it does not
490 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
appear to us, concluded that infants just born and imbeciles
do not belong to the human species (as, in fact, the author
states that he has conversed with very reasonable persons who
made this denial), I do not think that the bad use of the
maxim, that it is impossible for a thing to be and not to be,
would delude them, nor that they think of it even in drawing
this conclusion. The source of their error would be an exten
sion of the principle of our author, which denies that there is
anything in the soul of which it is not conscious, \vhile these
gentlemen would proceed as far as to deny the soul itself,
when others did not perceive it.
CHAPTER VIII
OF TKIFLIX<; PROPOSITIONS
Ph. I believe, indeed, that reasonable persons have not
been disinclined to employ identical axioms in the way of
which we have just spoken. §2. It also seems that these
purely identical maxims are only trifling propositions or nugnto-
rice-, as the schools indeed call them. I should not be content
to say that they seem thus, did not your surprising example
of the demonstration of conversion by the agency of the identi
cals l make me proceed, bridle in hand, thenceforth, when
contempt for an \ thing is the question. But T shall tell you
that what you allege in their favor proclaims them wholly
trifling; viz. : ('§ 3) you recognize at first sight that they con
tain no instruction unless to show a man sometimes the ab
surdity in which he is involved.
Th. Do you count that as nothing, sir, and do you not recog
nize that to reduce a proposition to absurdity is to demonstrate
its contradictory? I indeed believe that you will instruct no
man by telling him that he must not deny and affirm the same
thing at the same time, but you instruct him by showing him
by the force of the consequence, that he does this without
thinking of it. It is difficult, in my opinion, ahvays to pass
1 Cf. y<*w Kxxriit*, Bk. TV., chap. L', ante, p. 4<M>. — TR.
c 1 1. vin] ON HUMAN UM>K ^STANDING 491
from these ci/pagoc/ical demonstrcitions,i.e. demonstrations which
reduce to absurdity, and to prove everything by the ostensives,1
as they are called; and geometers, who are very curious on
this point, have tried it sufficiently. Proclus speaks of it
from time to time, when he sees that certain ancient geome
ters, coming after Euclid, have found a demonstration more
direct (as they think) than his. But the silence of this an
cient commentator sufficiently shows that they did not always
accomplish it.
jj .'). P/t. You will at least admit, sir, that a million proposi
tions may be formed at little expense, but also of very little
use; for is it not trifling to remark, for example, that the
oyster is the oyster, and that it is false to deny it, or to say
that the oyster is not the oyster'/ As to which our author
agreeably says that a man who would make this oyster some-
tim'es the subject, sometimes the attribute, or the predicatum,
would justly be like a monkey who should amuse himself by
throwing one oyster from one hand to the other, which pro
ceeding could altogether as well satisfy the hunger of the
monkey as these propositions are capable of satisfying the
understanding of man.
Th. I find that this author, as full of intelligence as gifted
with judgment, has every reason in the world for speaking
against those who would so use them. But you certainly set'
how the identicals must be employed to render them useful;
viz. : by showing by force of consequences and definitions that
<>tlujr truths which you wish to establish reduce to them.
$ 4. Ph. I know it and I see clearly that they may be
applied with much stronger reason to propositions which
appear trifling and on many occasions are so, wherein a part
of the complex idea is affirmed of the object of this idea, as
in the statement: lead ?'.s« metal. In the mind of a man who
is acquainted with the meaning of these terms and who knows
that lead signifies a very heavy fusible and malleable body,
there is this use alone, that in saying metal, you indicate to
him at once many simple ideas instead of enumerating them
one by one. § T>. The same is true when part of the defini-
'• I.e. direct demonstrations, a term used as the opposite of the indirect or
<i[xirio<lica1 demonstrations, which show the truth of a tiling by proving the
absurdity of denying it. — TR.
492 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
tion is affirmed of the thing defined; as in the statement:
all gold is fusible, supposing you have defined gold as a yellow,
heavy, fusible, and malleable body. Again, to say that the
triangle has three sides, that man is. an animal, that a palfrey
(palefroy, an old French word) is an animal which neighs,
serves to define the words, but not to teach anything besides
the definition. But we learn something from the statement
that man has a notion of God and that opium plunges him
into sleep.
Th. Besides what I have said of the identicals which are
wholly so, we shall find that these semi-identicals have also a
particular use. For example, a ivise mem is always a man;
that gives us the knowledge that he is not infallible, that he
is mortal, etc. Some one in danger needs a pistol-ball, and
lacks the lead to found it in the form he has ; a friend says
to him : remember that the silver you have in your purse is
fusible; this friend will not teach him a quality of the silver,
but will make him think of a use he may make of it, in order
to have pistol-balls in this pressing need. A large part of
moral truths and of the most beautiful sentences of authors is
of this nature: they very often teach us nothing, but they
make us think at the right time of what we know. That
iambic senarius of the Latin tragedy, —
Cuivis potest accidere, quod cuiquam potest,1
which might be expressed thus, although less prettily: that
which may happen to one, may happen to everybody, only
makes us remember the human condition, quod nihil humani a
nobis alienum putare debemus.2 This rule of the jurisconsults :
qui jure suo utitur, nemini fadt injuriam 3 (he who uses his
1 Publilius Syrus, in Seneca, De Tranquillitate, chap. 11. — TR.
2 Cf. Terence, Heauton. 1. 1. 23-25: " Homo sum; humani nihil a me alie
num puto." — TR.
3 Schaarschmidt states that this rule of the jurisconsults comes from the
"Ref/ulseet prsecepta juris," which were customarily appended to the older
editions of the Instilutiones. The exact phrase does not occur in the Corpus
Juris Civilis; but cf. Digest, Lib. XXXIX., Tit. II., 24, ad fin., where Trebatius
says: " non teneri me damni infecti: neque enim existimari, operis mei vitio
damnum tibi dari in ea re, in qua jure meo usus sum " ; ib. 26: " Proculus ait,
cum quis jure quid in suo faceret," etc.; Digest, Lib. L., Tit. XVII., 55, where
Gaius says: " Nullus videtur dolo facere, qui suo jure utitur " ; ib. 129, where
Paulus says: " Nihil dolo creditor facit, qui suum recipit." — TR.
CH. vi n] ON HUMAN UNDERSTANDING 493
own right, injures no one) appears trifling. But it is very
useful on certain occasions and makes one justly think of
what is necessary. If, for instance, any one raised his house
as far as he is allowed by the statutes and usages, and by so
doing deprived his neighbor of some view, he would pay this
neighbor at once, according to this rule of law, if he ventured
to complain. For the rest, propositions of fact, or experiences,
like that which states that opium is a narcotic, carry us farther
than the truths of pure reason, which can never make us go
beyond that which is in our distinct ideas.1 As for this propo
sition, that every man has a notion of God, it is from the
reason, since notion signifies idea. For the idea of God, ac
cording to my view, is innate in all men: but if this notion
signifies an idea in which you actually think it, it is a propo
sition of fact which depends on the history of the human race.
§ 7. Finally, to say that a triangle has three sides is not so
identical as it seems, for a little attention is required to see
that a polygon must have as many angles as sides; it would
also have an additional side, if the polygon were not supposed
to be closed.
§ 9. Ph. It seems that the general propositions concerning
substances are for the most part trifling, if they are certain.
He who knows the meanings of the wrords : substance, man,
animal, form, soul, vegetative, sensitive, rational, will form
from them many indubitable but useless propositions, partic
ularly about the soul, of which we often speak without know
ing what it really is. Every one may see an infinite number
of propositions, reasonings, and conclusions of this nature in
the books of metaphysics, scholastic theology, and a certain
kind of physics, the reading of which will teach him nothing
more of God, spirits, and bodies than he knew before having
run through these books.
Th. It is true, that abstracts of metaphysics and such other
books of this character as are commonly seen, teach only
words. To say, for example, that metaphysics is the science
of being in general, which explains the principles and affec
tions emanating from it; that the principles of being are
1 Truths of fact furnish occasion for inductive conclusions which enlarge
our knowledge ; while truths of reason can only be explicated, or made clearer
as to their already existing content. — TR.
494 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
essence and existence; that the affections are either primi
tive, viz. : unity, truth, the good, or derivative, viz. : iden
tity, diversity, simplicity, complexity, etc., and, in speaking
of each of these terms, to give only vague notions and verbal
distinctions is indeed to abuse the name of science. But we
must render this justice to the more profound Scholastics,
like Suarez l (whom Grotius valued so highly) and admit that
there is sometimes in them discussions of value, as upon the
continuum, the infinite, the contingent, the reality of abstracts,
the principles of individuation, the origoet vacuum formarum,
the soul and its faculties, the concurrence of God with his
creatures, etc., and even in ethics, upon the nature of the
will and the principles of justice ; in a word, we must admit
that there is still some gold in these scoriae, but it is only
enlightened persons who can profit from it; and to load the
youth with the rubbish of inutilities, because there is some
thing of value here and there, would be badly to dispose of
the most precious of all things, time. For the rest, we are
not wholly destitute of general propositions regarding sub
stances which are certain, and deserve to be known; there are
grand and beautiful truths concerning God and the soul which
1 Francisco Suarez, 1548-1G17, a famous Jesuit and a distinguished philoso
pher, theologian, and philosophical jurist, was "the last great Scholastic."
In philosophy he was a moderate Thomist. As a theologian, he advocated the
system known as " congruism." In his Tractatus de legibus etc Deo legislators,
reprinted, London, 1679, wherein he was to a certain extent the forerunner of
Grotius and Pufendorf, he maintained the theory of conditional obedience to
authority. For an account of his views on natural law and sovereignty, cf.
Larousse. Grande Diet. Univ. de XlXe Siecle,Vo\. 14, pp. 1164c-ll(J5a; for
his "congruism," ibid., Vol.4, p. 9:34 a. His Opera omnia, 23 vols., fol., ap
peared at Mainz and Lyons, 1630 sq., Venice, 1640, new revised ed., 2(5 vols.,
8vo, Besancon and Paris, 1856-02. The most important of his works are, per
haps, the Disputat tones metaphysicse, 1605, and the Tract, de lea., cited above.
For an account of his philosophy, cf. Stockl, Gesch. de Philos. d. Mittelalters,
III. [Vol. 4], 634 *q., and K. Werner, Suarez u. d. frcholastik d. letzten Jahr-
hunderte, Regensburg, 1861.
Huig van Groot — Latin, Hugo Grotius — cf. ante, p. 285, note 1, one of the
founders of the philosophy of law, in his theological writings occasionally cites
Suarez as an authority ; cf., for example, Opera omnia theolouica, Amsterdam,
1679, Vol. 4, pp. 206, a, 50, 621, a, 54; and in his Epistolse ad Gallos, epist. 154
ad Joa. Cordesium, p. 335, ed. Leipzig, 1674, and new ed. 1684, also Epistolae
quotquot reperiri potuerunt, epist. 329, p. 118, Amsterdam, 1687, praises him
thus: " Quorsum tantus Suarezii contemtus? hominis, si quid recte jndico,
in philosophia cui hoc tempore connexa est scholastica, tantse subtilitatis, ut
vix quemquam habeat parem? " — TR.
CH. vin] ON HUMAN UNDERSTANDING 495
our clever author has taught either in his own right or in
part after others. We have perhaps added something also
thereto. And as for general knowledge concerning bodies,
considerable additions are being made to what Aristotle left,
and it should be said that physics, even general physics, has
become much more real than it was heretofore. As for real
metaphysics, we are beginning, as it were, to establish it, and
we find important truths grounded in reason and confirmed by
experience, which belong to substances in general. I hope,
also, that I have advanced a little the general knowledge of
the soul and of spirits. Such a metaphysic was the demand
of Aristotle, it is the science which he called Z-^rou/xeV^, the
desired (la desiree) or that which he sought, which must be as
regards the other theoretic sciences what the science of happi
ness is to the arts which it needs, and what the architect is to
the workmen. This is why Aristotle said that the other
sciences depend upon metaphysics as the most general science
and must derive from it their principles, demonstrated by it.1
You must know also that true ethics is to metaphysics what
practice is to theory, because upon the doctrine of substances
in common depends the knowledge of spirits and particularly
of God and the soul which gives a proper meaning to justice
and virtue. For as I have elsewhere 2 remarked, if there were
neither providence nor a future life, the wise man would be
more limited in the practice of virtue, for he would refer
everything merely to his present satisfaction, and even this
satisfaction, which appears already in Socrates, in the em
peror Marcus Aurelius, in Epictetus and other ancients,3
1 Cf. Aristotle, Metaphys., A, 2, 982M)83a, the object of which is to prove
the dependence of the other sciences upon metaphysics, and in which the term
<rjTeiV frequently occurs in this specific sense ; <:f. especially 982 b, 7, 8: e£ a-rrav-
T(av ovv Twf eipr^fj-fvoiv em rrfv avrr^v €7ri(rTJj/u.T)f rriTTTei TO ^VjTOVju.ei'Oj' OVO/J.OL, For the
comparison to the architect, cf. 1, 981a, 30. — TR.
2 Leibnitz refers perhaps to what he said in New Ksscn/s, Bk. I., chap. 2,
§ 2, Th. (2), ante, pp. 86-87; or in the Preface to his Codex juris r/e-ntivm
diplomaticus, § 13 (Dutens, 4, Pt. III., 29<>) : " Ut vero universal! demonstra-
tione conficiatur, omne honestum esse utile, et omne turpe damnosum, assu-
menda est immortalitas animae, et rector universi Deus," etc. — TR.
3 Marcus Aurelius Antoninus, 121-180, the noblest of the Roman Emperors,
whose Meditations or Thoughts exhibit the Stoic, philosophy at its best on the
moral and religious side, and present a morality nearer to that of the New
Testament than that of any other pagan writer. Eds. of the Greek Text
TO. ei? avrov by J. M. Schultz, Leipzig, 1802, reprinted by Tauchnitz, 1821, and
496 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
would not be so well grounded always without these beautiful
and grand views which the order and harmony of the universe
open for us even in a future without limits; otherwise the
tranquillity of the soul would be only what is called a forced
patience, so that we may say that natural theology, comprising
two parts, theoretical and practical, contains altogether real
metaphysics and the most perfect ethics.1
§ 12. Ph. There is doubtless knowledge which is far re-
by J. Stich, Leipzig, 1882. Eng. trans., The Thoughts of the Emperor M.
Aurelius Antoninus, by Geo. Long, revised ed. in Bohn's Class. Library; also
Boston: Ticknor and Fields, 1864. On his life and philosophy, cf. Zeller,
Philos. d. Griech., III., 1 [Vol. 5], 754-763, 3d ed., 1880; Capes, Stoicism (in
series of " Chief Anct. Philosophies," pub. by the Soc. for promoting Chris
tian Knowledge), chap. 13, pp. 200-239, London, 1880; F. W. Farrar, Seekers
after God, pp. 257-317, London, Macmillan & Co., 1877.
Epictetns, the date of whose birth and death is unknown, lived in Rome
under Nero, 54-68, and his successors, and, when Domitian in 94 banished all
philosophers from the Imperial City, went to Nicopolis in Epirus, and there
taught till his death, which appears to have occurred in the reign of Trajan,
98-117, or shortly after. At first a slave, but afterwards a freedman, he repre
sented Stoicism in the cottage, while in Aurelius we see it on the throne. He
left no writings, but his discourses, Aiarpi/Scu, were carefully taken down as
far as possible in his own words as he uttered them. l;y his pupil and admirer
Arriau. The best ed. is that by Schweighauser, (5 vols., 8vo, Leipzig. 1799-
1800. Eng. trans., The Discourses of Epictetas, with the Encheiridion and
Fragments, by Geo. Long, in Bohn's Class. Library; also byT. AV. Higginson,
Boston: Little, Brown & Co., 1865. On his life and philosophy, cf. Zeller,
Philos. d. Griech., III., 1 [Vol. 5], 738-754, 3d ed., 1880; Capes, Stoicism, chap.
12, pp. 180-199; Farrar, Seekers after God, pp. 186-251), London, 1877. — TR.
1 The old scholasticism made natural theology a part of metaphysics, which
included besides natural theology, ontology, cosmology, and psychology. Cf.
Thos. Aquinas, Summa. Thcol., Pt. I., Quest. 1, Art. 1, ad Jin. : " Unde theo-
logia, qu<B a 1 sacram dortrinarn pertiiiet, differt secundtim genus ab ilia theo-
logia quffi pars philosophise ponitur." Leibnitz, in a writing without place or
date, which Gerhardt (Leibniz, philos. Schrift., 4, 268, note **) thinks was
undoubtedly addressed to the Duchess Sophie, says (G. op. cit,., 4, 292, and
Foucher de Careil, Nouvelles lettres et opuscules de Leibniz inedits, Paris,
1857, p. 25) : "En effect la metaphysique est la theologie naturelle, et le memo
Dieu qui est la source de tous les biens, est aussi le principe de toutes les cou-
noissances." Cf. also Discours de metaphi/s., § 28, G. 4, 453.
Leibnitz finds the source of ethical truths in natural theology, because God,
the idea of whom is the subject of natural theology, is also the object of man's
highest moral aspiration and effort, so far as he seeks lovingly to comprehend
him, a point of view from which Leibnitz sought to develop the ethical con
ceptions published under the title of De/initiones ethicge, G. 7, 73 sq., Erdmann,
670, trans. Duncan, Philos. Wks. of Leibnitz, 130, and which controls the
thought-development in the Preface to the Codex juris gentium diplomaticus,
rf. § 13, Dutens, 4, Pt. III., 296, in the Theodicee, Preface, G. 6, 215-28, E.469,
Jacques, 2, 3-4, Janet, 2, 3-4, and in the Discours de metaphys., §§ 2-4, 35-37,
G. 4, 427-430, 460-463. — TR.
en. ix] ON HUMAN UNDERSTANDING 497
moved from being trifling or purely verbal. But this last
seems to be that in wliich two abstracts are affirmed the one
of the other; for example, that parsimony is frugality, that
gratitude is justice; and however specious these and other
propositions sometimes appear at first sight, yet when we
press their force, we find that it all amounts to nothing else
than the signification of the terms.
Th. But the significations of terms, i.e. definitions united
with identical axioms, express the principles of all demonstra
tions: and as these definitions can make known at the same
time the ideas and their possibility, it is plain that what
depends on them is not always purely verbal. As for the
example that gratitude is justice, or rather a part of justice, it
is not to be despised, for it shows that what is called actio
iugrati,1 or the complaint which can be made against the
ungrateful, should be • less neglected in the tribunals. The
Romans received this action against the Liberti,2 or freedmen,
and still to-day it should have place as regards the revocation
of gifts. For the rest, I have already said elsewhere3 that
abstract ideas also may be attributed to one another, the genus
to the species, as in the statements : duration is a continuity,
virtue is a habit; but universal justice is not only a virtue,
but it is indeed the complete ethical virtue.
CHAPTER IX
OF OUR KNOWLEDGE OF OUR EXISTENCE4
§ 1. Ph. We have hitherto considered only the essences of
things, and as our mind knows them only by abstraction, by
detaching them from every particular existence, other than
that which is in our understanding, they give us absolutely
no knowledge of any real existence. And the universal prop-
1 Cf. Cod. Justin., 8, 56, 1, 8, and 10. — TR.
2 Gerhardt, Erdmann, and Janet read "les libertes"; Jacques reads "les
libere's." — TR.
3 Cf. Bk. III., chap. 3, § 10, Th., ante, p. 313. — TR.
4 Locke's title is, " Of our knowledge of existence." Philos. Works, Vol. 2,
p. 228, Bonn's ed.— TR.
2 K
498 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
ositions of which we may have a certain knowledge, do not
relate to existence. Further, every time we attribute anything
to an individual of a genus or a species by a proposition, which
would not be certain if the same were attributed to the genus
or species in general, the proposition belongs only to the exist
ence and makes known only an accidental union in the things
existing in particular, as when we say, such a man is learned.
Th. A7ery well, and it is in this sense that the philosophers
also, distinguishing so often between what is essence and what
existence, refer to existence everything which is accidental or
contingent. Very often we do not even know whether the uni
versal propositions, which we know only by experience, are
not perhaps accidental also, because our experience is limited ;
as in the countries where water is not frozen, this proposition
which will be formed about it, that water is always in a fluid
state, is not essential, and we know it by coming into colder
countries. But we may take the accidental in a more limited
sense, so that there will be, as it were, a mean between it and
the essential; and this mean is the natural (le naturel), i.e. that
which does not belong to the thing necessarily, but which,
nevertheless, agrees with it of itself if nothing prevents.
Thus, some one might maintain that it is not indeed essen
tial, but that it is at least natural, for water to remain fluid.
We might maintain this, I say, but it is not, however, a
demonstrated fact, and perhaps the inhabitants of the moon,
if there are any, would have reason to believe the statement
no less grounded that it is natural for water to be frozen.
There are other cases, however, where the natural is less
doubtful; for example, a ray of light always continues straight
in the same medium unless it accidentally meets some surface
which reflects it. For the rest, Aristotle was accustomed to
refer to matter the source of accidental things ; 1 but then we
must understand thereby secondary matter, i.e. the heap or
mass of bodies.
§ 2. Ph. I have already 2 remarked, following the excellent
English author who wrote the Essay concerning Understand
ing, that we know our existence by intuition, that of God by
1 Cf. MetapliyS., E, 2, 1027 a, 14: ia<rre ^ vXrj eerrai airia rj evSexofJiev^ napa TO o>?
€7Tl TO TTOAO ttAAo)? TOU (TV fJ.fi e fir) K OTOS. TR.
2 Cf. Bk. IV., chap. 3, § 21, ante, p. 439.— TR.
CH. x] ON HUMAN UNDERSTANDING 499
demonstration, and that of other things by sensation. § 3.
Now this intuition which makes known our existence to our
selves, makes it known to us with an evidence complete,
incapable of being proved and having no need of proof 5 so
that even when I attempt to doubt all things, this doubt itself
does not allow me to doubt my own existence. In fine, we
have on this point the highest degree of certainty that can be
imagined.
Th. I am entirely agreed as to all this. And I add that
the immediate apperception of our existence and of our
thoughts furnishes us the first truths a posteriori, or of fact,
i.e. the first experiences, as the identical propositions contain
the first truths a priori, or of reason, i.e. the first lights (les
premieres lumieres).1 Both are incapable of proof, and may be
called immediate; the former, because they are immediate
between the understanding and its object; the latter, because
they are intermediate between the subject and the predicate.
CHAPTER X
OF OUR KNOWLEDGE OF THE EXISTENCE OF GOD
§ 1. Ph. God having given to our soul the faculties with
which it is adorned, has not left himself without a witness;
for the senses, perception, and the reason furnish us manifest
proofs of his existence.
Th. God has not only given the soul faculties suitable for
knowing him, but he has also impressed upon it characters
which indicate him, although the soul needs faculties to per
ceive these characters. But I do not wish to repeat the discus
sions we have already had upon ideas and innate truths,
among which I reckon the idea of God and the truth of his
existence. Let us come rather to the fact.
Ph. Xow, although the existence of God is the truth most
easily proved by the reason, and its evidence equals, if I am
not mistaken, that of mathematical demonstrations, it yet
demands attention. It needs at once only reflection upon
1 Schaarschmidt translates : "die ersten Erleuchtungen aus dem Innern,"
i.e. the first illuminations from within. — TR.
500 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
ourselves and our own indubitable existence. § 2. Thus I sup
pose that every one knoivs that something actually exists, and that
thus there is a real being. If there is any one who can doubt
his own existence, I declare that I do not speak to him. § 3.
We know also by an intuitive knowledge that bare nothing can
not produce a real being. Whence it follows, with mathemat
ical evidence, that something has existed from all eternity, since
everything which has a beginning must have been produced
by something else. § 4. Xow every being which draws its
existence from another, draws also from it all it has, and
all its faculties. The eternal source of all beings is then
also the principle of all their powers, so that this eternal being
must be also all-powerful. § 5. Further, man finds in himself
knowledge. There is, then, an intelligent being. Xow it is im
possible for a thing absolutely destitute of knowledge and per
ception to produce an intelligent being, and it is contrary to
the idea of matter, deprived of thought, to produce it of itself.
The source of things is then intelligent, and there has been an
intelligent being from all eternity. § G. An eternal, very power
ful, and very intelligent being is what we call God. If, how
ever, any one were found so unreasonable as to suppose that
man is the only being having knowledge and wisdom, but that,
nevertheless, he has been formed by pure chance, and that it
is this same principle, blind and without knowledge, which
carries on all the rest of the universe, I shall advise him to
examine at his leisure the wholly solid and emphatic censure
of Cicero ("De Legibus," lib. 2). Certainly, he says, no one
could be so foolishly arrogant as to think that he has within
himself an understanding and reason, and yet that there is no
intelligence governing the heavens and all this vast universe.1
From what I have just said it clearly follows that we have a
more certain knowledge of God than of anything else outside us.
Tli. I assure you, sir, with perfect sincerity, that I am ex
tremely sorry to be obliged to say something against this
demonstration; but I do it solely in order to give you an op
portunity to fill up the void. It is principally in the part
1 Cicero, De Lee/., Bk. II., chap. 7: "Quid est enim verius, quam neminem
esse oportere tarn stulte arrogantem, ut in se rationem et mentem putet inesse,
in coelo mundoque non putet? Aut ut ea quse vix summa ingeuii ratione com-
prehendat, nulla ratione moveri putet? " — TR.
CH. x] ON HUMAN UNDERSTANDING 501
where you conclude (§ 3) that something has existed from all
eternity. I find therein some ambiguity, if that means that
there never has beoi any time in ichich nothing existed. I admit
it, and it follows truly from the preceding propositions by
an inference wholly mathematical. For if there had always
been nothing, there would always have been nothing, nothing
being unable to produce a being; then we ourselves should not
be, which is contrary to the first truth of experience. But the
consequence appears at once, that by the statement that some
thing has existed from all eternity, you mean an eternal
thing. But it docs not at all follow in virtue of what you
have hitherto advanced, that if there has always been some
thing, there has always been a certain thing, i.e. an eternal
being. For certain opponents will say that I have been pro
duced by other things, and these things by others. Further,
if some admit eternal beings (as the Epicureans their atoms)
they will not think themselves compelled for that reason to
admit an eternal being who is the only source of all the
others. For if they should admit that this w.hich gives exist
ence, gives also the other qualities and powers of the thing,
they will deny that a single thing gives existence to the
others, and they will say also that in each thing many others
must concur. Thus we shall not reach by this alone a source
of all the powers. Yet it is very reasonable to judge that
there is one, and also that the universe is governed with wis
dom. But when we believe matter susceptible of thought, we
may be disposed to believe that it is not impossible that it
may produce something. At least it will be difficult to bring
forward a proof which does not show at the same time that it
is wholly incapable of it; and, assuming that our thought
comes from a thinking being, may we take it as admitted,
without prejudice to the demonstration, that this must be
God?
§ 7. Ph. I do not doubt that the excellent man from whom
I have borrowed this demonstration is capable of perfecting
it; and I shall try to influence him to do so, since he could
scarcely render a greater service to the public. You also de
sire it. This makes me think that you do not consider it
necessary, in order to shut the mouths of atheists, to make
everything revolve upon the existence of the idea of God in
502 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
us, as some do, who attach themselves too strongly to this
favorite discovery even to rejecting all other demonstrations
of the existence of God,1 or at least attempting to weaken
them and forbidding to employ them as if they were weak or
false ; although at bottom they are proofs which show us so
clearly and in a manner so convincing the existence of this
sovereign being by the consideration of our own existence,
and of the sensible parts of the universe, that I think no wise
man ought to resist them.
Th. Although I am for innate ideas, and in particular for
that of God, I do not think that the demonstrations of the
Cartesians drawn from the idea of God are perfect. I have
shown fully elsewhere 2 (in the "Actes de Leipsic," and in
the " Memoires de Trevoux ") that what Descartes has bor
rowed from Anselm,8 Archbishop of Canterbury, is very beau-
1 Descartes relied mainly, and Spinoza exclusively, on the ontological or a
priori argument for the proof of God's existence. Spinoza's system, in fact,
did not admit the possibility of any other argument, since God is the only sub
stance and all other things are merely modes, accidents, or expressions of that
substance. Cf. Descartes, Meditations, III. and V., Veitch's trans., pp. 115 sq.,
143 sq., Prinrip. Philos., Ft. I., §§ 13 sq., Veitch, pp. 198*?., Discours de la
Methode, Ft. IV., Veitch, pp. 34 sq.; Spinoza, Kthica, Ft. I., ed. Van Vloten and
Land, Vol. 1, pp. 39 sq., trans. Elwes, Vol. '2, pp. 45 sq.; letter to De Vries,
V. V. & L., 2, 34, trans. E. 2, 315. Also on Descartes. Windelband, Hist, of Philos.,
trans, by Tufts, 392-3, 405 ; on Spinoza, ibid., 401, 407-10. Leibnitz, while seek
ing to correct and complete the ontological argument, makes the teleological
form of the a posteriori argument, in his doctrine of monads and their pre-
established harmony, one of the constituent principles of his system. Cf. Con-
fessio naturae contra atheistas, 1668, Gerhardt, 4, 105-109, Erdmann, 45-47,
Dutens, 1, 5-8; Principes de la nature et de la </rdee, §§ 11 sq., G. (i, 603, E.
716, trans. Duncan, 214, Monadoloyie, §§ 38 sq., G. 6, 613, E. 708, trans. D.. 223.
Leibnitz's doctrine of monads demands the existence of God as its necessary
ground and complement. Cf. ante, p. 363, note 1. He regarded all the argu
ments for God's existence as valuable and urged men to perfect them. Cf.
infra, p. 505, note 2. On his doctrine, cf. Windelband, op. cit., 420-425. — TR.
2 Leibnitz means the Med. de Co;/., Ver. et Id., published in the " Acta
Erud. Lips.," Nov., 1684, and found in Gerhardt, 4, 422, Erdmann, 79, Dutens,
2, Ft. L, 14, Janet, 2, 514 (in French), trans. Duncan, 27 ; and the De la demon
stration Cartesienne, etc., published in the " Memoires de Trevoux," 1701, G.
4, 405, E. 177, Dutens, 2, Ft. L, 251, Janet, 2, 568r trans. Duncan, 136.— TR.
3 Anselm, 1033-1109, archbishop of Canterbury from 1093 till his death, and
the real founder of the Christian Scholasticism of the Middle Age, was a dis
tinguished philosopher and theologian, whose fame rests chiefly upon his onto
logical or a priori argument for the existence of God, and his theory of the
incarnation and atonement. His Opera are found in Migne, Patrol. Cur.
Com.pl., Vol. 155. The most important for philosophy are the Cur Deus
Homo?, the Monologium, and the Prosloyium. The two latter, with Gaunilo's
ON HUMAN UNDERSTANDING 503
tiful and really very ingenious, but that there is still a gap
therein to be filled. This celebrated archbishop, who was
without doubt one of the most able men of his time, congratu
lates himself, not without reason, for having discovered a
means of proving the existence of God a priori, by means of
its own notion, without recurring to its effects. And this is
very nearly the force of his argument : God is the greatest,
or (as Descartes says) the most perfect of beings, or rather a
being of supreme grandeur and perfection, including all de
grees thereof. That is the notion of God. See no\v how
existence follows from this notion. To exist is something
more than not to exist, or rather, existence adds a degree to
grandeur arid perfection, and as Descartes states it, existence
is itself a perfection. Therefore this degree of grandeur and
perfection, or rather this perfection which consists in exist
ence-, is in this supreme all-great, all-perfect being : for otherwise
some degree would be wanting to it, contrary to its definition.
Consequently this supreme being exists. The Scholastics,
not excepting even their Doctor Angelicus,1 have misunder-
refutation of the Prosloginm, entitled Liber pro insipiente, and Anselm's
reply, Liber apoloyeticus, were edited by C. Haas, Tubingen, 1863. There is
a French trans., with notes, of the Monolor/ium and Proslof/ium by Bouchitte,
Le Rationalistic Chretien, Paris, 1842: and an English trans, of the Pros-
logium and Lib. apoloyet. in the " Bibliotheca Sacra," Vol. 8 [1851], pp. 529
sq., 704 sq., and of the Cur Deus Homo?, ibid., Vol. 11 [1854], pp. 729 sq., 12
[1855], 52 .«<?. His ontological argument is found in the Proslof/iam and the
Liber apolor/eticus. An excellent account of it is given in Ueberweg-Hein/e,
Gesch. d. Philos., 7th ed., Berlin, 1888, Vol. 2, p. 152 sq., Eng. trans, from 4th
German ed., New York, 1871, Vol. 1, pp. 383-86. Cf. also Windelband, Hist,
of Philos., trans, by Tufts, pp. 291-294; Mulford, The Republic of God, pp. 4,
5, 4th ed., Boston, 1882. For further account of Anselm's life and philosophy,
cf. Hasse, Ansdm ron Canterbury, 2 vols., Leipzig, 1843, 1852 (ontolog. argt.
in Vol. 2, pp. 233-28*)) ; Stu'ckl, Gesch. d. Philos^ d. Mittelalters, 1, 151-208;
Haureau, Hixtoire de la Philos. Scholastique, Paris, 1872-80, 1, 2(55-87.
For expositions and criticisms of the ontological argument, cf. Kant, Krit.
d. r. Vernunft., ed. Rosenkranz and Schubert, 2, 4(52-470, ed. Hartenstein,
1838, 2, 45(5-4(54, 18(57, 3, 405-411, ed. Kirchman, Leipzig, 1877, 1, 47(5-48:5, trans.
Miiller, 1 vol. ed., 509-518; E. Caird, The Philos. of Kant, Glasgow, 1877,
630, 642, The Crit. Philos. of Kant, New York, 1889, 2, 110, 120: Hegel,
Vorlesunyen ii. d. Beweise vom Dasein Gottes, in his Philos. d. Relif/.,
Anhang, 2, 357 sq., 2d ed., Berlin, 1840; Dorner, Christ. Glaabenslehre, 1, 201
sq., Eng. trans., 1, 214 sq. ; Pfleiderer, Philos. d. Rdia., 2, 271 sq., 2d ed.,
Berlin. 1884, Eng. trans., 3, 271 sq. — TR.
1 I.e. Thomas Aquinas, 1225 or 1227-1274. For his critique of the ontologi
cal argument, cf. Xumma theoloyise, Pt. I., Quest. 2, Article 1; Contra gen
tiles, Bk. I., chap. 11 ; and Stock!, Gesch. d. Philos. d. Mittelalters, II., 1 [Vol.
504 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
stood this argument, and have taken it as a paralogism; in
which respect they were altogether wrong, and Descartes,
who studied quite a long time the scholastic philosophy at the
Jesuit College of La Fleche, had great reason for re-establish
ing it. It is not a paralogism, but it is an imperfect1 demon
stration, which assumes something that must still be proved
in order to render it mathematically evident; that is, it is
tacitly assumed that this idea of the all-great or all-perfect
being is possible, and implies no contradiction. And it is
already something that by this remark it is proved that,
assuminy that God is possible, he exists, which is the privilege
of divinity alone. AVe have the right to presume the possi
bility of every being, and especially that of God, until some one
proves the contrary. So that this metaphysical argument
already gives a morally demonstrative conclusion, which de
clares that according to the present state of our knowledge we
must judge that God exists, and act in conformity thereto.
But it is to be desired, nevertheless, that clever men achieve
the demonstration with the strictness of a mathematical proof,
and I think I have elsewhere 2 said something that may serve
this end. The other argument of Descartes, which under
takes to prove the existence of God because the idea of him is
in our soul, and must have come from the original, is still less
conclusive. For in the first place this argument has this de
fect, in common with the preceding, that it assumes that there
is in us such an idea, i.e. that God is possible. For what
Descartes alleges, that in speaking of God we know what we
2], 498. Spinoza also censures Aquinas for his rejection of the ontological
argument; cf. Korte Verhande'linf/ ran God, in Spinoza, Opera, ed. Van Vlo-
ten and Land, Vol. 2, p. 2(55, and Schaarschmidt's German trans, of the same
(Vol. 18 of J. H. v. Kirchmann's Philos. Bibliotliek), p. 6, 2d ed., Berlin,
1874. — TR.
1 G rhardt rea'ls " parfaite " ; Erdmann, Jacques, and Janet " imparfaite."
The reading of G. is evidently a Ms. or typographical error, as the sense
requires that of E., J., and J. — TR.
- Leihnitz here probaHy refers to the De la demonstration Cctrtesienne,
etc., 1701, G"rh;u-dt, 4, 405, Erdmann, 177, Dutens, 2. Pt. I., 254, trans. Dun
can, 1:56. But cf. also G. 4, 292-294, 401-403, trans. Duncan, 132-186; Animad-
versiones in YKI -teiti f/eneraleni Pnncipiorum Cartes ianorum, 1692, Pt. I., ad
art. 14, 18, 20, G. 4, 358-60. trans. Duncan, 50-51, and Letters to Jacquelot,
Nov., 1702, G. 3, 442 sq., Letter to Conring, Jan. 3, 1678, G. 1, 188, E. 78; cor
respondence with Eckhard, G. 1, 212 sq. : and Stein, Leibniz ?/. Spinoza, Bei-
lage VII., p. 306: Probatio existenttsc Dei ex ejus essentia. — Ti;.
CH. x] ON HUMAN UNDERSTANDING 505
are saying, and that consequently we have an idea, is a decep
tive indication, since in speaking of perpetual mechanical
movement, for example, we know what we are saying, and
yet this movement is an impossible thing, of which, conse
quently, we can have only an apparent idea. Secondly, this
same argument does not sufficiently prove that the idea of
God, if we have it, must come from the original. But I do
not wish to delay here at present. You will say, sir, to me,
that recognizing in us the innate idea of God, I ought not to
say that we may question whether there is one. But I per
mit this doubt only in relation to a strict demonstration based
upon the idea alone. For we are otherwise sufficiently assured
of the idea and of the existence of God. And you will re
member that I have shown how ideas are in us, not always in
such wise that we are conscious of them, but always in such
wise that we may draw them from our own depths and make
them perceivable. And this is also my belief concerning the
idea of God, the possibility and existence of which I hold to
be demonstrated in more than one way. And the pre-estab
lished harmony itself furnishes a new and incontestable means
of so doing.1 I believe also that nearly all the means which
have been employed to prove the existence of God are good
and might be of service, if we would perfect them, and I am
not at all of the opinion that we should neglect that drawn
from the order of things.'2
§ 9. Ph. It will perhaps be proper to insist a little upon this
question, whether a thinking being can come from a non
thinking being deprived of all sensation and knowledge such
as matter may be. § 10. It is indeed quite evident that a
part of matter is incapable of producing anything of itself,
and of giving itself motion; its motion must then either be
eternal or be impressed upon it by a more powerful being. If
this motion were eternal, it would always be incapable of pro
ducing knowledge. Divide matter into as many little parts as
you please, in order, as it were, to spiritualize it, give it all
1 Cf. ante, p. 363, note 1. — TR.
2 Leibnitz's idea is that all right thought, if thorough-going and deep enough,
must at last lead hack to God, its original source. None of the proofs of God's
existence are therefore to be cast aside, hut the essential significance of each
is to be sought out and ascertained and its form perfected, and all are to he
united into one organic whole. — TR.
506 LEIBNITZ'S CRITIQUE OF LOCKE [BK.
figures and motions yon wish, make it a globe, a cube, a prism,
a cylinder, etc., whose diameters are only the one-millionth
part of a gry, which is one-tenth of a line, which is one-tenth
of an inch, which is one-tenth of a philosophical foot, which
is one -third of a pendulum, each vibration of which in the
latitude of forty-five degrees is equal to one second of time.
This particle of matter, small as it is, will act upon other
bodies of a size proportional to itself no differently than
bodies of an inch or a foot in diameter act among them
selves. And we may hope as rationally to produce feeling,
thought, and knowledge, by putting together gross parts of
matter in a certain figure and motion, as by means of the
smallest parts of matter in the world. These last knock,
push, and resist each other just as the great ones do, and this
is all they can do. But if matter could draw from its bosom
feeling, perception, and knowledge, immediately and with
out machinery, or without the aid of figures and motions,
then their possession must be an inseparable property of
matter and of all its parts. To which one could add that,
though the general and specific idea we have of matter
leads us to speak of it as if it were a thing single in num
ber, yet all matter is not properly one individual thing, which
exists in a material being or a single body that we know or
can conceive. So that if matter were the first eternal think
ing being, there would not be one eternal infinite and think
ing being, but an infinite number of eternal infinite l thinking
beings, independent of one another, whose forces would be
limited and thoughts distinct, and who consequently could
never produce this order, harmony, and beauty which is seen
in nature. Whence it necessarily follows that .the eternal
first being cannot be matter. I hope that you, sir, will be
more content with this reasoning taken from the celebrated
author of the preceding demonstration than you have appeared
to be with his demonstration.
Th. I find the present reasoning the most solid in the
world, and not only exact, but further profound and worthy of
its author. I am perfectly of his opinion that no combination
and modification of the parts of matter, however small they
1 Locke has "finite" here, Philos. Works, Vol. 2, p. 237, Bohn's ed. Ger-
hardt, Erdmann, Jacques, and Janet all read " iufinis." — TR.
CH. x] ON HUMAN UNDERSTANDING 507
may be, can produce perception; forasmuch as the gross par
ticles could not give it (as is manifestly admitted) and as
all is proportional in the small parts to what may take place
in the great. It is furthermore an important remark regard
ing matter which the author makes here, that it must not be
taken as a thing single in number, or (as I have been wont
to state it) as a true and perfect monad or unity, since it is
only a mass of an infinite number of beings. Here this excel
lent author needed but a step to arrive at my system. For in
fact I give perception to all these infinite beings, each one of
which is like an animal endowed with a soul (or some active
analogous principle which makes its true unity), together
with what is necessary to this being in order to be passive
and endowed with an .organic body. Xow these beings have
received their nature, active as well as passive (i.e. what they
have of immaterial and material), from a general and supreme
cause, because otherwise, as the author very well says, being
independent of one another, they could never produce this
order, harmony, and beauty which is seen in nature. But
this argument, which appears to possess only a moral certainty,
is pushed to a necessity wholly metaphysical by the new kind
of harmony I have introduced, which is the pre-established har
mony. For each one of these souls expressing in its way what
takes place outside it and being unable to have any influence
on other particular beings, or rather, being obliged to draw
this expression from the depths of its own nature, each one
must necessarily have received this nature (or this internal
reason of the expression of that which is outside) from a
universal cause upon which all these beings depend and which
makes one perfectly in accord and correspondent with another ;
a thing impossible without an infinite knowledge and power
and with an artifice great as regards especially the spontane
ous agreement of the mechanism with the acts of the rational
soul. The illustrious author 1 who made objections against it
1 Leibnitz here refers to Pierre Bayle, 1647-1706, a celebrated critic, philoso
pher, and controversialist, who published in his IHctionnaire historique et
critique, Rotterdam, 1695-97, 2 vols., 2d ed., revised and enlarged, 1702, article
" Rorarius," a criticism of Leibnitz's Systems nouveau de la nature, etc., pub
lished in the " Jour, des Savants," June, 1(595, pp. 449 sq. Leibnitz sought to
repel his criticisms in a writing, July, 1698, addressed to Basnage de Beauval,
editor of the " Histoire des ouvrages des S9avans," and published therein,
508 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
in his wonderful Dictionary doubted, as it were, whether this
condition of things did not surpass all possible wisdom, saying
that the wisdom of God did not appear to him too great for
such an effect, and recognized at least that never had the
feeble conceptions we may have of the divine perfection been
so set in relief.
§ 12. Ph. How delighted I am at this agreement of your
thoughts with those of my author! I hope you will not be dis
pleased, sir, if I give you an account also of the rest of his
reasoning upon this article. First he examines whether the
thinking being, upon whom all the other intelligent beings
depend (and with much stronger reason all other beings) is
material or not. § 13. It is objected that a thinking being
might be material. But lie replies that- if that were so, it is
enough that this be an eternal being which has an infinite
knowledge and power. Further, if thought and matter can be
separated, the eternal existence of matter will not follow
from the eternal existence of a thinking being. § 14. It will
further be asked of those who make God material whether
they imagine that every part of matter thinks. In that case
it will follow that there would be as many Gods as particles
of matter. But if each part of matter does not think, then
there is a thinking being composed of non-thinking parts,
which has already been disproved. § 15. To say that any
single atom of matter thinks, and that the other parts,
July, 1608, p. 329*7., e/. Gerhardt, Leibniz, philos. Srhrift., 4, 517-24, Erdmann,
150-154, Jacques, 1, 481-87, Dutens, 2, Ft. I., 74-80. In the 2d ed. of his Diction-
naii-e, p. 259!) sq., Eng. trans, from 2d ed., carefully collated with the several
eds. of the original, 5 vols., London, 1738, 4, 900-916, Bayle again discussed
Leibnitz's views, and to this discussion Leihnitz made a thorough and search
ing reply, first published by Gerhardt, 4, 524-54, with the title: Extract du
Dictionnalre de M. Bayle, article Rorarius, p. 2599 sqq. de V Edition de ran
1702 avcc me a remarques. Leibnitz pub. a revision of this detailed refutation,
in 1712, in the " Histoire critique de la Republique des Lettres," Vol. 2, p. 78
xq. Gerhardt has published it, 4, 544-71, with many additions by Leibnitz.
Cf. also Erdmann, 183-191, Dutens, 2, Pt. I., 80-93, Janet. 2, 579-94. Leibnitz
elsewhere frequently refers to Bayle, especially in the Theodictfe, in the pre
liminary essay entitled, Discours preliminaire sur confonnite de lafoi arec la
raison, in which Bayle's objections are carefully examined, and in Pts. II. and
III., where he is cited on nearly every page, and which presents a continuous
polemic against him. The composition of the Theodice'e was occasioned by the
discussions held by Leibnitz with Queen Sophie Charlotte of Prussia on philo
sophical and theological topics suggested by the reading of Bayle's Dictionary.
For the correspondence of Leibnitz and Bayle, cf. Gerhardt, 3, 21 sq. — TR.
CH. x] ON HUMAN UNDERSTANDING 509
though equally eternal, do not think, is to make the gratuitous
statement that one part of matter is infinitely above another
and produces thinking beings not eternal.1 § 16. If we will
have it that the thinking eternal and material being is a cer
tain particular mass of matter whose parts are non-thinking,
we fall back upon the view which has been disproved ; for the
parts of matter are united in vain, they can acquire only a
new local relation, which cannot give them knowledge. § 17.
It matters not whether this mass is at rest or in motion. If
at rest, it is only an inactive mass which has no privilege
above one atom; if in motion, since this motion, which distin
guishes it from other parts, is destined to produce thought,
all these thoughts will be accidental and limited, each part by
itself being without thought, and having nothing which regu
lates its movements. Thus there will be neither freedom, nor
choice, nor wisdom, any more than in simple brute matter.
§ 18. Some believe that matter is at least coeternal with God.
But they do not say why : the production of a thinking being,
which they admit, is much more difficult than that of matter
which is less perfect. And perhaps (says the author) if we
would withdraw ourselves a little from common ideas, give
wings to our mind, and engage in the profoundest examina
tion we could make of the nature of things, tee might be able to
attain a conception, though in an imperfect manner, how matter
may at first fyave been made, and how it commenced to exist by
the power of this eternal first being. But we should see at the
same time that to give being to a spirit is an effect of this
eternal and infinite power much more difficult to comprehend.
But because this would perhaps lead me too far (he adds)
from the notions upon ivhich the philosophy noiv in the world is
based, it would not be excusable in me to deviate so far from
them or to inquire, so far as grammar would permit, whether
at bottom the commonly established opinion is contrary to
this particular view; it would be wrong, I say, for me to
engage in this discussion, especially in this corner of the world,
Avhere the received doctrine is good enough for my purpose,
since it posits as an indubitable thing that if the creation or
beginning of any substance whatever from nothing be once
1 Leibnitz anticipates this argument of Locke by his law of continuity. —
TR.
510 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
admitted, the creation of every other substance, except the
Creator himself, may with the same facility be assumed.
Th. You have given me genuine pleasure, sir, by giving me
some account of a profound thought of your clever author,
which his too scrupulous prudence has prevented him from
producing in its entirety. It would be a great wrong, if he
should suppress it and leave us there, after having made our
mouths water. I assure you, sir, that I believe there is some
thing beautiful and important concealed behind this enigmati
cal manner.1 The substance in large letters might make one
suspicious that he conceives the production of matter in the
same way as that of the accidents, which we find no difficulty
in drawing from nothing: and in distinguishing his particular
thought from the philosophy now prevalent in the icorld or in that
corner of the earth, I do not know but that he had in mind the
Platonists, who take matter as something fleeting and transi
tory, after the manner of the accidents, and had an altogether
different idea of spirits and souls.
§ 19. Ph. Finally, if some deny creation, by which things
are made from nothing, because they cannot conceive it, our
author, writing before he knew your discovery on the reason
of the union of the soul and the body, holds against them,
that they do not understand how voluntary movements are pro
duced in bodies by the will of the soul, and they cease not to
believe the fact, being convinced by experience^ and he re
plies with reason to those who answer that the soul being una
ble to produce a new motion, produces only a new determina
tion of the animal spirits, he replies to them, I say, that the
one is as inconceivable as the other. And nothing can be
better said than what he adds on this occasion, that to wisli
to limit what God can do to what we can comprehend, is to
give an infinite extent to our comprehension, or to make God
himself finite.
Th. Although now the difficulty regarding the union of the
soul and the body has in my view been removed, there remain
difficulties elsewhere. I have shown a posteriori by the pre-
1With regard to this riddle or enigma, Professor Schaarschmidt informs me
that Raspe, in his ed. of the Noitveaux Essais, 17t>5, says, p. 40!) : '% Mr. Coste
1'a explique d'apres le Chevalier Newton dans la remarque (2) an § 18, de ce
chapitre. Edition de Locke d'Amsterdam, de 1755, p. 523." — TR.
CH. xi] ON HUMAN UNDERSTANDING 511
established harmony, that all the monads have received their
origin from God and depend upon him. But we cannot com
prehend the how in detail; and at bottom their conservation
is nothing else than a continual creation,1 as the Scholastics
have very clearly recognized.
CHAPTER XI
OF OUR KNOWLEDGE OF THE EXISTENCE OF OTHER THINGS
§ 1. Ph. As, then, the existence of God only has a necessary
connection with ours, the ideas we may have of anything no
more prove the existence of this thing than the portrait of a
man proves his existence in the world. § 2. The certainty,
however, I have of black and white upon this paper by means
of sensation is as great as that of the motion of my hand,
which is second only to the knowledge of our own existence,
and of that of God. § 3. This certainly deserves the name of
knowledge. For I do not believe that any one can seriously be
so sceptical as to be uncertain of the existence of things which
he sees and feels. At least, he who can carry his doubts so
far will never have any controversy with me, since he can
never be certain that I say anything contrary to his opinion.
The perceptions of sensible things § 4. are produced by exter
nal causes which affect our senses, for we do not acquire these
perceptions without the organs, and if the organs sufficed,
they would always produce them. § 5. Further, I sometimes
experience the fact that I cannot prevent these ideas from
being formed in my mind, as, for example, the light, when I
have my eyes open in a place into which the light may enter:
while I can lay aside the ideas which are in my memory.
There must be, then, some external cause of this living im
pression whose efficacy I cannot overcome. § 6. Some of these
1 Cf. Observatio ad Recensionem libri de Fidei et Rat ionis con sensu a Do
mino Jaqueloto editi, tnense Octobri proxime prsecedenti factam, pub. in the
" Acta Erud. Lips.," Dec. 1705, p. 558, ad fin., Gerhardt, 6, 55(5-8, Erdmann,
433-4, Dutens, 2, Ft. I., 256-8; Theodicee, Ft. III., §§ 382, 385, 391-3, G. 6,
842, E. 614, Jacques, 2, 2SK), Janet, 2, 388, Dutens, 1, 387; Pichler, Die The-
oiogie des Leibniz, 1, 252, Miinchen, 1869; Monadoloyie, § 47, G. 6, 614, E. 708,
Jacques, 2, 397, Janet, 2, 601, trans. Duncan, 225; Nolen, Leibniz, La Mona-
dologie, 3d ed., Paris, 1893, pp. 148, 211. — TR.
512 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
impressions are produced in us with pain, although afterwards
we remember it without feeling the least inconvenience. And
although mathematical demonstrations do not depend on the
senses, yet the examination made of them by means of dia
grams is of much use in proving the evidence of our sight, and
seems to give to it a certainty approaching that of demonstra
tion itself. § 7. Our senses also in many cases bear witness
to each other. He who sees the fire may feel it if in doubt of
it. And in writing this, I see that I can change the appear
ance of the paper, and say beforehand what new idea it is
going to present to the mind; but, when these characters are
traced, I can no longer avoid seeing them as they are, in
addition to the fact that the sight of these characters will
make another man utter the same sounds. § 8. If any one
thinks that all this is but a long dream, he may dream, if he
pleases, that I make this response to him, that our certainty
based upon the testimony of our senses is as perfect as our
nature allows, and our condition demands. He who sees a
candle burning, and tries the heat of the flame, which hurts
him if he does not withdraw his finger, will not ask for a
greater certainty in order to govern his actions, and if this
dreamer did not so do (i.e. withdraw his finger) he would find
himself awakened. Such an assurance then suffices us, which
is also as certain as pleasure or pain, two things beyond which
we have no interest in knowledge or the existence, of things.
§ 9. But beyond our actual sensation, there is no .knowledge,
and it is only probability, as when I believe that there are men
in the world; of which fact there is a high degree of probabil
ity, although at present, alone in my chamber, I see none of
them. § 10. It is also folly to expect a demonstration of every
thing and to act not in accord with clear and evident truths
though they are not demonstrable. A man who should so
use them could be assured of nothing but of dying in a very
short time.
Th. I have already remarked in our preceding conferences
that the truth of sensible things is justified by their connec
tion,1 which depends upon the intellectual truths grounded in
reason and upon constant observations in the sensible tilings
1 Cf. New Essays, Bk. IV., chap. 2, § 14, Th. (2), ante, p. 422, note 1. From
the idealistic point of view, the only possible criterion of the truth of the phe-
CH. xi] ON HUMAN UNDERSTANDING 513
themselves even when the reasons do not appear. And as
these reasons and observations give us the means of judging
the future as related to our interest, and as success corresponds
with our rational judgment, we could not demand, nor have
indeed, a greater certainty regarding these objects. We can
also give a reason for dreams themselves, and for their slight
connection with other phenomena. Nevertheless, I believe
that we might extend the appellation of knowledge and of
certainty beyond actual sensations, since clearness and mani-
festness go beyond, which I consider as a species of certainty;
and it would undoubtedly be folly seriously to doubt whether
there are men in the world when we do not see any. To doubt
seriously is to doubt in relation to the practical, and we might
take certainty as a knowledge of truth which we cannot doubt
in relation to the practical without madness; and sometimes
we take it still more generally, and apply it to cases where
we could not doubt without deserving to be severely blamed.
But evidence would be a luminous certainty, i.e. where we do
not doubt because of the connection we see between ideas.
According to this definition of certainty, we are certain that
Constantinople is in the world, that Constantine, Alexander
the Great, and Julius Caesar lived. It is true that some peas
ant of Ardennes might justly doubt about these, for lack of
information; but a man of letters and of the world could not
do so without great derangement of mind.
§ 11. Ph. We are assured in truth by our memory of many
things which are past, but we shall not be able to judge easily
whether they exist still. I saw yesterday water, and a certain
number of beautiful colors upon bubbles formed upon this
water. Now I am certain that those bubbles as well as that
water existed, but I do not know with any more certainty the
present existence of the water than that of the bubbles,
although the former is infinitely more probable because the
water has been observed to be lasting and the bubbles to dis
appear. § 12. Finally, outside of ourselves and God we know
other spirits only by revelation, and we have concerning them
only the certainty of faith.
nomena of the senses is the constancy and regularity in their connection or
consecution. Cf. also De modo distinyuendi phenomena realia ab imayina-
riis, Gerhardt, Leibniz, philos. Schrift., 7, 319 sq. ; Erdmanu, 443-445. — TR.
2 L
514 LEIBNITZ'S CRITIQUE OF LOCKE [BK. IT
Th. It has already been remarked that our memory some
times deceives us. And we put confidence in it or not, accord
ing as it is more or less vivid, and more or less connected with
the things we know. And even when we are assured of the
principal fact we may often question the circumstances. I
remember to have known a certain man, for I feel that his
image as well as his voice is not new to me; and this double
indication is a better guarantee to me than one of the two, but
1 cannot remember where I have seen him. It happens, how
ever, though rarely, that a person is seen in a dream before he
is seen in flesh and blood. And I am assured that a lady of a
well-known court saw in a dream arid described to her friends
the person she afterwards married, and the hall in which the
betrothal was celebrated, and she did this before she had seen
or known either the man or the place. They attributed the
circumstance to some indefinite secret presentiment; but
chance may produce this effect, since it is quite rare that it
happens, besides, dream-images being somewhat obscure, there
is more liberty in connecting them afterwards with certain
others.
§ 13. Ph. Let us conclude that there are two kinds of prop
ositions, the one particular and concerning existence, as, for
example, that an elephant exists; the other general, concern
ing the dependence of ideas, as, for example, that men should
obey God. § 14. The majority of these general and certain
propositions bear the name of eternal truths, and, in fact, they
all are such. This is not because these are propositions act
ually formed somewhere from all eternity, or because they
are graven upon the mind after some model, which always
existed, but because we are assured that when a creature en
riched with faculties and means therefor, applies his thoughts
to the consideration of his ideas, he Avill discover the truth
of these propositions.
Th. Your division appears to return to mine of propositions
of fact and propositions of reason. Propositions of fact also
may become general in a way, but it is by induction or obser
vation, so that it is only a multitude of similar facts, as when
it is observed that all quicksilver is evaporated by the force
of fire; and this is not a perfect generality, because we do
not see its necessity. General propositions of reason are
CH. xi] ON HUMAN UNDERSTANDING 515
necessary, although the reason also furnishes some which are
not absolutely general, and are only probable, as, for example,
when we presume an idea to be possible until its contrary is
discovered by a more exact research. There are finally mixed
propositions, drawn from premises, some of which come from
facts and observations, and others are necessary propositions;
and such are a number of geographical and astronomical con
clusions regarding the globe of the earth and the course of the
stars, which spring from the combination of the observations
of travellers and astronomers with the theorems of geometry
and arithmetic. But as, according to the usage of logicians,
the conclusion follows the weakest of the premises l and cannot
have more certainty than they, these mixed propositions have
only the certainty and generality which belong to the obser
vations. As for the eternal truths, it must be observed that at
bottom they are all conditional and say in effect: such a thing
posited, such another thing is. For example, in saying: every
figure ivhich has three sides will also hate three angles, I say
nothing else than that, supposing there is a figure with three
sides, this same figure will have three angles. 1 say this
same, and it is in this respect that the categorical proposi
tions which may be stated unconditionally, although at bot
tom conditional, differ from those called hypothetical, as this
proposition would be: if a figure has three sides, its angles are
equal to two right angles, in which we see that the antecedent
proposition (viz. : the figure of three sides) and the consequent
(viz. : the angles of the figure of three sides are equal to two
right angles) have not the same subject as they have in the
preceding case, in which the antecedent was : this figure has
1 The variously phrased formula : conclusio sequitur partem debiliorem or
deteriorem ; sectetur partem conclusio deteriorem ; pejorem sequitur semper
conclusio partem, is the Scholastic expression of the fundamental principle of
the categorical syllogism, according to which the conclusion cannot contain
more than is contained in the premises, or, as given by Hamilton (Lects. on
Logic, p. 219, Boston, 1873), in his third rule of the syllogism, "The conclu
sion must correspond in quantity with the subsumption [minor premise], and
in quality with the sumption [major premise]." Logicians regarded negative
and particular propositions as weaker or worse as related to universal and
affirmative propositions, the negative being weaker in quality and the par
ticular in quantity, so that in the syllogism if one of the premises is particular
the conclusion will be particular, and if one of the premises is negative the
conclusion will be negative. For the history of the subject, cf. Prautl, Gesch.
d. Logik, 1, 371, 587 ; 2, 275 ; 3, 48. — TR.
516 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
three sides, and the consequent: the said figure has three angles.
Although, again, the hypothetical may often be transformed
into the categorical, merely by changing a little the terms,
as if instead of the preceding hypothetical, I said : the angles
of every figure ivith three sides are equal to two right angles.
The Scholastics have hotly disputed de constantia subjecti, as
they called it, i.e. how the proposition made upon a subject
can have a real truth, if this subject does not exist. The fact
is that the truth is only conditional, and says, that in case the
subject ever exists, it will be found such. But it will be
further demanded, in what is this connection founded, since
there is in it some reality which does not deceive. The reply
will be, that it is in the connection of ideas. But it will be
asked in reply, where would these ideas be if no mind existed,
and what then would become of the real ground of this cer
tainty of the eternal truths? This leads us finally to the ulti
mate ground of truths, viz. : to that Supreme and Universal
Mind, which cannot fail to exist, whose understanding, to
speak truly, is the region of eternal truths, as St. Augustine
has recognized and expresses in a sufficiently vivid way.1 And
in order not to think that it is unnecessary to recur to this,
we must consider that these necessary truths contain the de
termining reason and the regulating principle of existences
themselves, and, in a word, the laws of the universe. Thus
these necessary truths being anterior to the existence of
contingent beings, must be grounded in the existence of a
i Aurelius Augustinus, 354-430, grounded his philosophy in the principle of
the absolute and immediate certainty of consciousness or inner experience.
Cf. De Beata Vita, chap. 7 ; Solil. II., 1 (ante, p. 410, note 1) ; De Ver.a Relig., 39,
72 sq. ; De Trin., X., 14, XIV., 7. In this certainty of the individual conscious
ness, i.e. in thought itself, is immediately involved the idea of God in whom
exist the universal truths as the ideas or norms of all reality. Cf. De Ideis, 2 :
" Sunt namque ideae principales form* quredam, vel rationes rerum stabiles et
incommutabiles, qua? ipsre format* non sunt atque per hoc aBternse ac semper
eodem modo se habentes, quse in divina intelligentia continentur, et quum
ipsse neque oriantur neque intereant, secundum eas tamen formari dicitur
omne, quod interire potest et omne, quod oritur et interit."
For a good account of Augustine's philosophy, cf. Ueberweg-Heinze, 7th
ed., Berlin, 1888, 2, 97-115, especially 106-7, Eng. trans, from 4th Germ, ed.,
New York, 1871, 1, 333 sq., especially 339-40; Windelband, Hist, of Philos.,
trans, by Tufts, 276 sq. Augustine's works form Vols. 32-47 of the La^tin
Fathers in Migne, Patrol, cur. compl., Paris, 1835 sq.; Eng. trans, by Dods,
15 vols., Edinburgh, 1871-77, and in Schaff's lib. Nicene and Post-Nicene
Fathers, Vols. 1-8, Buffalo, 1886-88. — TB.
CH. xn] ON HUMAN UNDERSTANDING 517
necessary substance. Here it is that I find the original of the
ideas and truths which are graven in our souls, not in the
form of propositions, but as the sources out of which applica
tion and occasion will cause actual judgments to arise.1
CHAPTER XII
OF THE IMPROVEMENT OF OUR KNOWLEDGE
§ 1. Ph. We have spoken of the kinds of knowledge we
have. Now let us come to the means of improving the knowl
edge or of finding the truth. It is the received opinion among
scholars, that the maxims are the bases of all knowledge, and
that each particular science is based upon certain things
already known (prcecognita). § 2. I admit that mathematics
seem to favor this method by their good success, and you have
given considerable support to this view. But it is still doubtful
whether it is not rather the ideas which were of service therein
through their connection than two or three general maxims
which were posited at the beginning. A young lad knows
that his body is greater than his little finger, but not by vir
tue of this axiom, that the whole is greater than its part.
Knowledge commenced by particular propositions; but after
wards it was desired to relieve the memory by means of gen
eral notions from a cumbersome load of particular ideas. If
language were so imperfect that there were no relative terms,
whole and part, could he not know that his body is larger than
his little finger? I at least give you the reasons of my author,
although I think I foresee what you will say thereto in con
formity with what you have already said.
Th. I know not why you bear the maxims such ill will as
to attack them yet again ; if they serve to relieve the memory
of a multitude of particular ideas, as you admit, they must be
very useful, although they had no other use. But I add that
i For Leibnitz God is the source of all truths as well as of all beings. The
idea of God contains in itself potentially all truth, and is the regulative (but
not in the Kantian sense of the term), or better, the constitutive, principle
of all thought, just as his actuality contains potentially within itself all exist
ences, and is the regulative, i.e., constitutive, principle of all being. Cf. also,
ante, p. 496, note 1. — TR.
518 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
they do not spring from particular ideas, for they are not
found by induction from examples. He who knows that ten
is more than nine, that the body is larger than the finger, and
that the house is too large to be able to run away with the
door, knows each one of these particular propositions, by one
and the same general reason which is, as it were, incorpo
rated therein and illuminated, just as we see designs adorned
with colors in which the proportion and configuration con
sists properly in the outlines, whatever the color may be.
Xow this common reason is the axiom itself which is known,
so to speak, implicitly, although it does not exist at first in an
abstract and separate manner. The examples derive their
truth from the incorporated axiom, and the axiom has not its
ground in the examples. And as this common reason of these
particular truths exists in the minds of all men, you see clearly
that it is not necessary that the words ichole and part be found
in the language of him who is imbued therewith.
§ 4. Ph. But is it not dangerous to authorize assumptions
under the pretext of axioms? One will assume, with some of
the ancients, that all is matter; another, with Polemo,1 that
the world is God; a third will assert that the sun is the prin
cipal divinity. Judge what a religion we should have, if that
were allowed. So true is it that it is dangerous to receive
principles without questioning them, especially if they con
cern morality. For some one will expect another life, like
that of Aristippus,2 who placed happiness in the pleasures of
the body, rather than like that of Antisthenes,3 who main-
1 Polemo, the successor of Xenocrates, .396-314 B.C., as scholarch, or head,
314-270 B.C., of the school of the Old Academy, and the third in that office
from Plato (Speusippus holding it from Plato's death in 347 to 3,39, and Xeno
crates from 339-314), devoted himself chiefly to ethics. The statement that he
declared the universe to be God — noAeju.oi' rov KOV^OV Oebv a-n^^vaTo — rests on
the authority of Stobams, Eclogse phys., Bk. 1., chap. 2, 5, § (>2, p. 15, ed. A.
Meineke. Leipzig, 1855-<>4. For his philosophy, c/. Zeller, Phllos.d. Griech.,
II., 1 [Vol. 3], 993-4, 1045-(>, 4th ed., Leipzig, 1889. — TR.
-Aristippus, c.43f>-c. 36H B.C., the founder of the Cyrenaic school, made
pleasure, which, according to Diog. Laertius, II., 85, 8(5, he defined as the
feeling of a gentle motion — reAos 6' airefyaivf. ^v \eiav xiv-qviv ei? CUO-0TJO-IV if a6i6o-
nevvv . . . TV ^tv \eiav Kn>r)<TLv r^v rjSoi/r^ — the end of life, the wise man aiming
to enjoy pleasure without being controlled by it. For his writings, c/. Mul-
lach, Frayt. philos. Gr., II., 397 sq. On his life and philosophy, cf. Zeller,
Philos. d. Griech., II., 1 [Vol. 3], 3,% sq., ethical doctrine, 352 ,sg. — TR.
;} Antisthenes, c. 440-c. 3(>9 B.C., a pupil of Gorgias and Socrates, was the
founder of the Cynic school, and taught, according to Diog. Laertius, VI., 11.
CH. xn] ON HUMAN UNDERSTANDING 519
tained that virtue suffices to produce happiness. And Arche-
laus,1 who will lay it down as a principle that justice and
injustice, honesty and dishonesty, are denned only by the laws
and not by nature, will no doubt have other measures of moral
good and evil than those who admit obligations anterior to
human constitutions. § 5. It must be, then, that principles are
certain. § 6. But this certainty comes only from the com
parison of ideas : thus we have no need of other principles,
and according to this rule alone we shall advance much farther
than by putting our minds at the disposal of another.
Th. I am astonished, sir, that you turn against maxims, i.e.
against evident principles, that which can and must be said
against principles assumed gratis. When one demands prce-
cognita in the sciences, or anterior knowledge, which serves
to ground science, he demands known principles and not arbi
trary positions, whose truth is not known ; and even Aristotle
understands that the inferior and subaltern borrow their prin
ciples from other superior sciences in which they have been
demonstrated, except the first of the sciences, which we call
metaphysics, which, according to him, asks nothing from the
others, and furnishes them the principles they need; and
when he says : Set TncrreiW TOV pavOdvovTa, 2 the apprentice must
that virtue only is a good, and that it is sufficient for happiness — avrdpic-r) yap
rrji/ aperrji' eiyai Trpo? euSat/xoriar. For his Writings, cf. Mllllacll, frttf/t . philoS.
Gr., II., 201 sq. On his life and philosophy, cf. Zeller, Philos. d. Griech., II., 1
[Vol. 3], 281 sq., ethical doctrine, 303 sq. — TR.
1 Archelaus, the dates of whose birth and death are unknown, was a physi
cist, and the disciple of Anaxagoras, c. 500-428 B.C., whose physical doctrine
he seems to have modified in the direction of the Ionic school as represented
by Anaximines, c. 588-c. 524 B.C., and Diogenes of Apollonia. Zeller says that
the statement, as given by Diog. Laertius, II., 16, that he derived the distinc
tion of good and bad from custom rather than nature — TO SiKaiov elvcu *ai TO
aio-xpbf ov 4>uo-et a\\a i/ojuw — appears to be due to a mistake in interpreting his
language, and that he merely said that men at the beginning were without
custom and .law, and first attained thereto in the course of time. On his
philosophy, cf. Zeller, Philos. d. Griech., I., 2 [Vol. 2j, 1031-1038, 5th ed.,
Leipzig, 181)2. — Tit.
a Cf. Aristotle, Sophist. Elench., chap. 2, 161, b, 1-3: Sifiao-KoAiKoi jxev oi e»c
Ttav oiKeitav ap\<at> e/cacrToti /uaftjj/oiaTO? <cai OVK e* TUIV TOV aifOKpivo^Lfvov 6o£dn/ (rvAAoyi^o-
ju-ei/ot (8ei -yap Trio-Ttveii' TOV /aa^dai/oi/Ta), i.e. discussions for the purpose of teach
ing proceed from the special principles of each science, and do not draw their
conclusions from the opinions of the participating pupil ; Aristotle's thought
being that the pupil will receive a confirmation of the mere faith in the prin
ciples demanded of him at the outset, in the course of the explanation and
demonstration of these principles in his presence, and in the agreement of the
scientific results with the facts and his further knowledge. Leibnitz here
520 LEIBNITZ'S CKITIQUE OF LOCKE [BK. iv
believe his master, his thought is that he must do it only while
waiting, while he is not yet instructed in the higher sciences,
so that it is only provisionally. Thus we are very far from
receiving gratuitous principles. To this it must be added that
even principles whose certainty is not complete may have
their use if we build upon them only by demonstration; for
although all the conclusions in this case are conditional only,
and are valid only upon the supposition that this principle is
true, nevertheless this connection itself and these conditional
enunciations would at least be demonstrated; so that it were
much to be desired that we had many books written in this
way, where there would be no danger of error, the reader or
disciple being warned of the condition. And practice will be
regulated by these conclusions only as the supposition shall
be found verified elsewhere. This method also serves very
often itself to verify suppositions or hypotheses, when many
conclusions arise from them, the truth of which is otherwise
known, and sometimes this gives a perfect proof (retour)
sufficient to demonstrate the truth of the hypothesis. Mr.
Conring,1 a physician by profession, but a clever man in every
kind of learning, except perhaps mathematics, wrote a letter
to a friend engaged in reprinting at Helmstadt the book of
Viottus,2 an esteemed Peripatetic philosopher who tried to
expresses a similar thought, in premising the provisional character of that
faith which the beginner should have in his teacher. — TB.
1 Hermann Conring, 1606-1681, one of the most learned men of his age,
possessed of vast erudition, and thoroughly informed on medicine, law, the
ology, history, physics, philology, etc., taught at Helmstadt, and wrote an
immense number of works, which have been united in part and published
under the title of Opera omnia, Brunswick, 1730, 7 vols., fol. For an account
of him, cf. Michaud, Biog. Univ., Vol. 9, pp. 447-452. For his correspondence
with Leibnitz, cf. Gerhardt, Leibniz, philos. Schrift., 1, 153-206. — TR.
2 Bartolommeo Viotto, or Viotti, surnamed a Clivolo, son of a distin
guished surgeon, Tommaso Viotto, who was the first in the University of
Turin to receive the laurel crown in surgery from the DecuriOns of Trino,
was a philosopher and physician of Turin, and, in the five years preceding
1552, public professor of logic in that city. He died in 1568. He was author
of De balneorum naturalium viribus lib. IV., Lugduni, 1552, reprinted in tie
balneis omnia quse extant apud Grsecos, Latinos, et Arabas, fol. Venetiis, 1553,
pp. 247-71 ; and of the work here and elsewhere referred to by Leibnitz,
-Demonstrationum in methodum medendi lib. V., 8vo, Parisiis, 1560, and under
the editorship of A. Frolingius, Helmstadt, 1661, Braunschweig, 1684. Cf.
Correspondence of Leibnitz and Conring, Gerhardt, Leibniz. philos. Schrift.,
1, 184, 187; of Leibnitz and Placcius, Dutens, Leibnit. op. om., 6, 45.
Conring, Introd. in univ. art. med., Halse et Lipsiae, 1726, p. 23, says of
CH. xn] ON HUMAN UNDERSTANDING 521
explain the demonstration and "Posterior Analytics" of
Aristotle. This letter was appended to the book, and in
it Conring criticised Pappus when he said that analysis
proposes to discover the unknown by assuming it, and by
reaching therefrom, by inference, known truths ; l a method
which is contrary to logic (he said) which teaches that from
falsehood we cannot infer truths. But I made known to him
afterwards that analysis makes use of definitions and other
reciprocal propositions which furnish means of making the
proof (retour), and of discovering synthetic demonstrations.2
And even when this proof is not demonstrative, as in physics,
it is nevertheless sometimes highly probable, when the hy
pothesis explains easily many phenomena, difficult without
it and very independent of one another. I hold to the
truth, sir, that the principle of principles is in a way the
good use of ideas and of experience; but by examining it
thoroughly we shall find that, as regards ideas, it is nothing
else than the union of definitions by means of identical axi
oms. Nevertheless, it is not always an easy thing to come to
this ultimate analysis, and whatever desire the geometers, at
least the ancient geometers, have shown to succeed therein,
they have not yet been able to do so. The celebrated author
him : " Certe qui necessitatem ejus in medicina simul et ipsam artem demon-
strandi post Galenum ostenderit, hactenus nemo inventus est, si excipias
unum Bartholomaeum Viottum hominem longe doctissimum ; cujus de demon-
stratione praeclarum opus ante centum annos prodiit." Cf., also, G. Paseh,
De novis inventis, "2d ed., 4to, Lipsiae, 1700, p. 26; J. A. van der Linden, De
scriptis medicis, 8vo, Amstelredami, 1(537, p. 82, Linden, renovat., 4to, Norim-
bergre, 1686, pp. 114, 119 ; Kestner, Medicinisches-Gelehrten-Lexicon, 4to, Jena,
1740, p. 897 ; G. G. Bonino, Biografia medica piemontese, 8vo, Torino, 1824,
Vol. 1, pp. 199-201. — TR.
1 Pappus of Alexandria was a Greek geometer " of a very high order," who
flourished, according to the best recent opinion, in the reign of Diocletian,
284-305, and whose Zwayuyj, or Collection, is of very great value in the his
tory of mathematics. From Bk. VII. of this work is derived a large part of
our knowledge of Greek geometry. The best ed. of the whole work is F.
Hultsch, Pappi Alexandrini Collectionis quse, supersunt, 3 vols., Berlin, 187(i-78.
Pappus' explanation of the nature of analysis and synthesis, which Con-
ring erroneously criticised, is found in the preface of Bk. VII. of the Swaywyr?,
cf. Hultsch, op. cit., Vol. 2, pp. (534-6; C. I. Gerhardt, Der Sammlung des
Pappus von Alexandrien, siebentes u. achtes Buck, Halle, 1871, pp. 2-4. Ac
cording to Schaarschmidt, this explanation is perhaps the clearest and best
concise statement that has been made of the nature of the analytic and syn
thetic method. — TR.
2 Cf. Correspondence of Leibnitz and Conring, Letter of Jan. 3d, 1678,
Gerhardt, Leibniz, philos. Schrift., 1, 187-8; also, ibid., 185, 190, 193 sq. — TR.
622 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
of " The Essay on Human Understanding," would give them
much pleasure if he would complete this investigation, a little
more difficult than we think. Euclid, for example, has put
among the axioms one which amounts to saying: that two
straight lines can meet only once. The image derived from
the experience of the senses, does not permit us to picture to
ourselves more than one meeting of the two lines; but it is
not upon this that science must be- founded. And if any one
believes that this image gives the connection of distinct ideas,
he is not sufficiently instructed concerning the source of truths,
and a multitude of propositions, demonstrable; by others ante
rior, would pass with him as immediate. Many of those who
have criticised Euclid, have not sufficiently considered this:
these kinds of images are only confused ideas, and he who
knows the straight lines only by this means will not be capable
of demonstrating anything. Kuclid, therefore, for want of a
distinctly expressed idea, i.e. a definition of a straight line (for
that which he gives meanwhile is obscure and of no use to him
in his demonstrations), was obliged to return to two axioms
which for him took the place of definitions and which he em
ployed in his demonstrations: the one that two straight lines
have no common part, the other that they enclose; no space.
Archimedes has given a kind of definition of the straiyht line,
in saying that it is the shortest line between two points. But,
he tacitly assumes (by employing in his demonstrations ele
ments like those of Kuclid, based upon the two axioms I have
just mentioned) that the properties (affections) of which these
axioms speak, accord with the line which he defines.1 Thus if
you believe, with your friends, under the pretext of the agree
ment or disagreement of ideas, that tfhat these; images tell us
was allowed and is still to be received in geometry, without
seeking that strictness of demonstration by means of defini
tions and axioms which the ancients demanded in this science
(as I believe many people; will believe for lack of information),
I will admit, sir, that you may be; contented as regards those
who trouble; themselves only about practical geometry such
as it is, but not as regards those who desire te> have the; science
which serves indeed to perfect the practical. And if the
ancients had been e>f this opinion and had relaxed their efforts
1 Gerhard t and Erdmaim read " definit " ; Jacques " deerit." — TR.
OH. xii] ON HUMAN UNDERSTANDING 623
on this point, I think they would have made but little advance,
arid would have left us only an empirical geometry such as
that of the Egyptians apparently was, and such as that of the
Chinese seems still to be; this would have deprived us of the
most worth ful physical and mechanical knowledge which
geometry has caused us to discover, and which is unknown
wherever our geometry is unknown. It is also apparent
that in following the, senses and their images we should fall
into errors; much the same as we see that all those who are
not instructed in exact geometry receive as an indubitable truth
upon trust in their imagination, that two lines continually
approaching each other, must finally meet; while geometers
give contrary instances in the case of certain lines called
asymptotes. Hut besides this we should be deprived of what
I value most highly in geometry as related to reflection, vi/. :
permitting us to catch a glimpse of the trim source of eternal
truths and of the means of making us comprehend their neces
sity, a matter which the confused ideas of the sense-images
could not show us distinctly. You will say to me that Euclid
was obliged, however, to confine himself to certain axioms
whose, evidence is seen only confusedly by means of the
images. 1 agree with you that he has limited himself to these
axioms, but it was better for him to limit himself to a. small
number of truths of this nature which appeared to him the
simplest and to deduce from them the, others which another
less exact would also have taken as certain without demonstra
tion, than to leave; many of them undcmonstrated, and what is
worse, to allow people the liberty of extending their laxity
according to their fancy. You sec then, sir, that what you
and your friends have said regarding the connection of ideas
as the true source of truths needs explication. If you are
willing to content yourself with the confused sight of this
connection, you weaken the exactness of demonstrations, and
Euclid has done incomparably better in reducing all to defini
tions and to a small number of axioms. Yet if you wish this
connection of ideas to be distinctly seen and expressed, you
will be obliged to recur to definitions and identical axioms,
as I claim; and sometimes you will be, obliged to content
yourself with some axioms less primitive, as Euclid and
Archimedes have done, when you find difficulty in attaining a
524 LEIBNITZ'S CRITIQUE OF LOCKE [BK. ir
perfect analysis, and you will do better in that way than to
neglect or defer some fortunate discoveries which you can
already make by their means : as in fact I have already said
to you at another time, sir, that I believe we should not have
a geometry (I mean a demonstrative science), if the ancients
had not been willing to advance until they had demonstrated
the axioms they were obliged to employ.
§ 7. Ph. I begin to understand what a distinctly known con
nection of ideas is, and I see clearly that in this sense axioms
are necessary. I see clearly also how necessary it is that the
method we follow in our researches, when the question is that
of the examination of ideas, be regulated by the example of
the mathematicians who from certain very clear and easy
beginnings (which are nothing else than the axioms and defi
nitions) proceed by small degrees and a continual chain of
reasoning to the discovery and demonstration of truths that
appear at first beyond human capacity. The art of finding
proofs, and these admirable methods they have invented for
separating and putting in order mediate ideas is what has
produced such wonderful and unexpected discoveries. But
whether with time a similar method may not be found out
useful in respect to other ideas as well as those belonging to
magnitude is a question I will not determine. At least, if
other ideas were examined according to the ordinary method
of the mathematicians, they would lead our thoughts farther
than we are perhaps led to imagine. § 8. And this might be
done particularly in the case of morality, as I have more than
once said.
Th. I believe you are right, sir, and I have been disposed
for a long time to make it my business to accomplish your
predictions.
§ 9. Ph. In regard to the knowledge of bodies we are com
pelled to take a directly contrary path; for having no ideas
of their real essences, we are obliged to recur to experience.
§ 10. But I do not deny that a man accustomed to making
rational and regular experiments is capable of forming juster
conjectures regarding their still unknown properties than
another not so accustomed, but it is judgment and opinion, not
knowledge and certainty. This makes me think that physics
is incapable of becoming a science in our hands. But experi-
CH. xn] ON HUMAN UNDERSTANDING 525
ments and historical observations may be of use to us as
regards the health of our bodies and the conveniences of life.
Th. I admit that physics as a whole will never be a per
fect science among us, but we shall not cease to be able to
have some physical science, and indeed we have already some
specimens of it. For example, magnetology may pass for
such a science, for, making a few suppositions based upon
experience, we can demonstrate from them by a certain infer
ence a number of phenomena which really occur as we see that
reason declares. We ought not to hope to give a reason for
all experiments, as indeed the geometers have not yet proved
all their axioms; but just as they are satisfied to deduce a
large number of theorems from a small number of principles
of the reason, so is it sufficient that the physicists by means
of certain principles of experience give a reason for a multi
tude of phenomena and can indeed prove them in practice.
§ 11. Ph. Since then our faculties are not fitted to make us
discern the internal fabric of bodies, we must consider that it
is enough that they discover to us the existence of God, and a
sufficiently extended knowledge of ourselves to instruct us in
our duties and in our greatest interests, particularly as related
to eternity. And I think I am right in inferring therefrom
that morality is the proper science and the important business of
mankind in general, as, on the other hand, the different arts which
are conversant about different parts of nature are the lot of par
ticular men. It may be said, for example, that ignorance of
the use of iron is a reason in the countries of America, where
nature has spread abroad abundantly all kinds of goods, for the
lack of the greatest part of the conveniences of life. Thus
very far from despising the science of nature, § 12. I hold,
that if this study is directed, as it ought to be, it may be of
greater use to the human race than all that has been done up
to this time; and he who invented printing, who discovered
the use of the compass, and who made known the virtue of
quinquina, has contributed more to the propagation of knowl
edge and to the advancement of the useful conveniences of
life, and has saved more people from the grave, than the
founders of colleges and hospitals and other monuments of
the most exemplary charity, which have been built at great
expense.
526 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
Th. You could say nothing, sir, more to my liking. True
morality or piety, very far from favoring the inactivity of cer
tain idle quietists, must impel us to cultivate the arts. And
as I said not long since, a better police would be able to bring
us some day a much better medical science than that we have
at present. AVe cannot preach this doctrine enough, next to
the care for virtue.
§ 13. Ph. Although I recommend experiments, I do not
despise probable hypotheses. They may lead us to new dis
coveries, and are, at least, a great aid to the memory. But
our mind has a great tendency to go too fast and to be satis
fied with certain superficial appearances, for lack of taking
the necessary time and trouble to apply them to a multitude
of phenomena.
Th. The art of discovering the causes of phenomena, or
true hypotheses, is like the art of deciphering, in which an
ingenious conjecture often greatly shortens the road. Lord
Bacon began to put the art of experimenting into precepts,
and Chevalier Boyle l had a great talent for practising it.
But if the art of employing experiments and of drawing con
sequences therefrom is not joined • with it, we shall never
with the utmost cost attain to what a man of great penetration
might discover at first sight. Descartes, assuredly such a man,
has made a similar remark in one of his letters 2 regarding the
method of the Chancellor of England; and Spinoza (whom I
do not hesitate to quote when he says a good thing) in one of
his letters 3 to the late Mr. Oldenburg, Secretary of the Royal
Society of England, printed among the posthumous works of
this subtle Jew, makes a similar reflection upon a work of
Boyle, who, to speak the truth, stops a little too much to
draw from a great number of fine experiments no other con-
1 Cf. ante, p. 324, note 2. — TR.
'2 The remark here referred to by Leibnitz as occurring in one of Descartes'
letters lias not as yet been found in any of those now extant ; and, as mention
is made of Bacon in Spinoza's remark cited immediately after, it is possible
that Leibnitz confounded the two authors, a thing which might readily happen,
especially as Leibnitz was often out of the reach of books when composing
his works, as probably in this case, cf. ante, p. 8, note 1. — TR.
3 Cf. Spinoza, Opera, ed. Van Vloten and Land, 2, 19: " Sed interim nescio,
cur clarissimus vir hoc" (i.e. universal mechanism) " adeo sollicite conetur
colligere ex hoc suo experirnento ; cum jam hoc a Verulamio, et postea a
Cartesio satis superque demon stratum sit." — TR.
CH. xn] ON HUMAN UNDERSTANDING 527
elusion than this which he might take as a principle, viz. : that
everything in nature takes place mechanically, a principle
which can be rendered certain by reason alone, and never by
experiments, whatever their number.
§ 14. Ph. After having established clear and distinct ideas
with fixed names, the great means of extending our knowl
edge is the art of finding mediate ideas which can show us the
connection or incompatibility of the extreme ideas. The max
ims at least are of no avail in furnishing them. Suppose a
man has not an exact idea of a right angle, he will vainly tor
ment himself in demonstrating something about the right-
angled triangle : and whatever maxims he employs, he will have
difficulty in attaining by their aid the proof that the first
squares of the sides enclosing the right angle are equal to the
square on the hypothenuse. A man might ruminate upon
these axioms a long time without ever seeing more clearly
into mathematics.
Th. It is of no avail to ruminate upon the axioms without
having something to which to apply them. Axioms often
serve to connect ideas, as, for example, this maxim, that similar
extensions of the second and third dimensions are in reason
double and triple the corresponding extensions of the first
dimension, is of very great use; and the quadrature, for ex
ample, of the lune of Hippocrates 1 springs from it at once in
the case of the circles by uniting therewith the application of
these two figures the one to the other, when their given posi
tion furnishes the opportunity for so doing, as their known
comparison promises light thereupon.
1 Hippocrates of Chios, c. 440 B.C., a contemporary of Hippocrates of Cos,
the physician (cf. ante, p. 476, note 2), was a celebrated Greek geometer, whose
most noted achievement was the discovery of the quadrature of the lune, or
the crescent-shaped plane figure produced by drawing two perpendicular radii
in a circle and describing upon the line joining their extremities a semicircle.
This lune is famous as the first curvilinear space whose area was exactly de
termined, and its area is exactly equal to that of the triangle formed by the two
radii and the line joining their extremities. For the demonstration of this,
c/. Larousse, Grande Diet. Univ. de XIX* Siede, Vol. 10, p. 701, a, b. On
Hippocrates and his services to mathematics, cf. Allman, Greek Geom.
from Thales to Euclid, (54 sq.; Gow, A Short Hist, of Greek Math., 164 sq.;
H. Suter, Gesch. d. math. Wissenschaften, 2d ed.. Vol. 1, pp. 33-36, Zurich
1873. -TR.
528 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
. CHAPTER XIII
OTHER CONSIDERATIONS CONCERNING OUR KNOWLEDGE
§ 1. Ph. It will be perhaps further appropriate to add, that
our knowledge has a close relation to our sight in this, as well
as in other things, that it is neither wholly necessary nor wholly
voluntary. We cannot fail to see when our eyes are open to
the light, but we can turn them towards certain objects, § 2.
and consider them with more or less application. Thus when
the faculty is once applied, it does not depend upon the will
to determine the knowledge; no more than a man can prevent
himself from seeing what he sees. But he must employ his
faculties, as it is necessary in order to inform himself.
Th. We have spoken before of this point, and established
the fact that it does not depend upon man to have this or that
opinion in the present state, but it depends upon him to pre
pare himself to have it or not to have it eventually, and that
thus opinions are voluntary only in an indirect manner.
CHAPTER XIV
OF JUDGMENT
' § 1 . Ph. Man would be found without direction in the
greater part of the arts of his life, if he had nothing to con
duct him from the point where certain knowledge fails him.
§ 2. He must often be contented with a simple twilight of prob
ability. § 3. The faculty of using this is judgment. One is
contented with it often of necessity, but often through want
of diligence, patience, and skill. § 4. It is called assent or
dissent, and is employed when anything is presumed, i.e. when
it is taken as true before it is proved. When this is done con
formably to the reality of things, it is a right judgment.
Th. Others call judgment the act which is performed every
time a statement is made after some knowledge of a cause;
and there will be some also who will distinguish judgment
CHS. xm-xv] ON HUMAN UNDERSTANDING 529
from opinion, as not of necessity being so uncertain. But I
do not wish to criticise any one regarding the use of words,
and it is allowed you, sir, to take judgment as a probable
opinion. As for presumption, which is a term of the juris
consults, good use with them distinguishes it from conjecture.
It is something more, something which must pass for truth
provisionally until there is proof of the contrary, while a
sign, a conjecture, must often be weighed against another con
jecture. Thus it is that he who admits having borrowed
money from another, is presumed to pay the debt, unless he
shows that he had done so already, or that the debt ceases by
some other principle. Presumption is not then in this sense
taking before proof, which is not allowed, but taking in advance
but with foundation, while awaiting a contrary proof.
CHAPTER XV
OF PROBABILITY
§ 1. Ph. If demonstration shows the connection of ideas,
probability is nothing else than the appearance of this connec
tion based upon proofs in which immutable connection is not
seen. § 2. There are several degrees of assent from assurance
down to conjecture, doubt, distrust. § 3. When there is cer
tainty, there is intuition in all parts of the reasoning which
show its connection; but what makes me believe is some
thing extraneous. § 4. Now probability is grounded in its
conformity with what we know, or in the testimony of those
who know.
Tli. I prefer to maintain that it is always grounded in like
lihood (vraisemblance) or in conformity with the truth; and
the testimony of another is also a thing which the truth has
been wont to have for itself as regards the facts that are
within reach. It may be said then that the similarity of the
probable and the truth is taken either from the thing itself,
or from some extraneous thing. The rhetoricians employ two
kinds of arguments: the artificial, drawn from things by rea
soning, and the non- artificial, based only upon the express
testimony either of man or perhaps also of the thing itself.
2 M
530 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
But there are mixed arguments also, for testimony may itself
furnish a fact which serves to form an artificial argument.
§ 5. Ph. It is for lack of similarity to truth that we do not
readily believe that which has nothing like that which we
know. Thus when an ambassador told the king of Siam that
with us the water was so hardened in winter that an elephant
might walk thereon without breaking through, the king said
to him : Hitherto I have believed you as a man of good faith ;
now I see that you lie. § 6. But if the testimony of others can
render a fact probable, the opinion of others should not pass
of itself as a true ground of probability. For there is more
error than knowledge among men, and if the belief of those
whom we know and esteem is a legitimate ground of assent,
men have reason to be Heathen in Japan, Mahometans in
Turkey, Papists in Spain, Calvinists in Holland, and Luther
ans in Sweden.
Th. The testimony of men is no doubt of more weight than
their opinion, and in reason it is also the result of more
reflection. But you know that the judge sometimes makes
them take the oath de credulitate, as it is called; that in the
examinations, we often ask witnesses not only what they have
seen but also what they think, demanding of them at the
same time the reasons of their judgment, and whether they
have reflected thereupon to such an extent as behooves them.
Judges also defer much to the views and opinions of ex
perts in each profession; private individuals, in proportion
as it is inconvenient for them to present themselves at the
appropriate examination, are not less compelled to do this.
Thus a child, or other human being whose condition is but
little better in this respect, is obliged, whenever he finds him
self in a certain situation, to follow the religion of the coun
try, so long as he sees nothing bad therein, and so long as he
is not in a condition to find out whether there is a better. A
tutor of pages, whatever his sect, will compel them each to
go to the church where those who profess the same belief as
this young man go. The discussions between Nicole 1 and
others on the argument from the great number in a matter of
1 Pierre Nicole, 102r>-l(>95, one of the most distinguished of the Port-Royal
ists, and, with the exception of Arnauld (cf. ante, p. 463, note 4) and Pascal, the
most accomplished member of the school, was author with Arnauld of the fa-
CH. xv] ON HUMAN UNDERSTANDING 531
faith may be consulted, in which sometimes one defers to it
too much and another does not consider it enough. There are
other similar prejudgments by which men would very easily
exempt themselves from discussion. These are what Tertul-
lian, in a special treatise, calls Prescriptiones,1 availing him
self of a term which the ancient jurisconsults (whose lan
guage was not unknown to him) intended for many kinds of
exceptions or foreign and predisposing allegations, but which
now means merely the temporal prescription when it is in
tended to repel the demand of another because not made with
in the time fixed by law. Thus there was reason for mak
ing known the legitimate prejudgments both on the side of the
Eoman Church and on that of the Protestants. It has been
found that there are means of opposing novelty, for example,
on the part of both in certain respects ; as, for example, when
the Protestants for the most part abandoned the ancient form
of ordination of clergymen, and the Eomanists changed the
ancient canon of the Old Testament books of Holy Scripture,
as I have clearly enough shown in a discussion I had in
writing, and from time to time, with the bishop of Meaux,
whom we have just lost, according to the news which came
some days since.2 Thus these censures being mutual, the
novelty, although it presents a suspicion of error in these
matters, is not a certain proof thereof.
mous IS Art de Penser or the Port Royal Logic. His most important work is
his Kxsais de Morale, Paris, KVT1-74. It was ahout his De I' unite de I'eglise ou
refutation du nouveau systeme de Jurien, Paris, 1(>87, that the theological
controversies here alluded to by Leibnitz centred, and " in which the question
was considered, whether Roman Catholicism allows itself to engage in the —
undoubtedly questionable — argument of the ' majority of professors.'" Ail
account of Nicole's De V unite de I'ec/lise will be found in Bayle's Diet., Eng.
transl., Vol. 4, p. Wti, London, 1737 . — TR.
1 Tertullian, 150-KiO — 220-240, sought in his De Prescriptions Hseretieorum
to produce a formal general argument against all heresies — " adversus hrere-
ses omnes " — his object being to prevent heretics, in accordance with certain
just and necessary rules (prsescriptiones), from appealing to Scripture in sup
port of their views. For an account of the work, cf. Smith and Wace, Diet,
of Christ, Bioy., Vol. 4, p. 837 a, sq. — TR.
2 Leibnitz here refers to his correspondence with Jacques Benigne Bossuet,
1627-1704, Bishop of Meaux from 1(581 till his death. This correspondence was
irenic in character, and extended, with some interruptions, over a period of
about 25 years, but was without result, because Leibnitz would not suffer the
freedom of scientific inquiry to be taken away, while Bossuet desired sub
jection to the infallible authority of the church. The entire correspondence
has been published by Foucher de Careil, (Etivres de Leibniz, Vols. 1, 2,
532 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
CHAPTER XVI
OF THE DEGREES OF ASSENT
§ 1. Ph. As for the degrees of assent,, we must take care
that the grounds of probability we have do not operate beyond
the degree of likelihood found therein or which has been found
therein when they are examined. For we must admit that
assent cannot always be based upon an actual view of the rea
sons which have prevailed with the mind, and it would be
very difficult even for those l who have an admirable memory
Paris, 1859-60. A portion of the same is found in Dutens, Leibnit. op. om., 1,
507 sq. The letters especially referred to are (1) of Leibnitz: Dec. 11, 1699,
(Foucher de Careil, (Etivres de Leibniz, 2, 274-277 ; Dutens, Leibnit. op. om., 1,
594-596), May 14 and 24, 1700 (F. 2, 314-369 ; D. 1, 612-642) ; (2) of Bossuet : Jan.
9 and 30, 1700 (F. 2, 278-300; D. 1, 596-611), Aug. 17, 1701 (F. 2, 396-426; D. 1,
657-673). For an account of the controversy, cf. Pichler, Die Theologie des
Leibniz, Vol. 2, pp. 206-215.
The present passage is important, as it enables us to determine the date of
the composition of the New Essays, or at least of this portion of them. Bos-
suet died April 12, 1704. This passage must then have been written in the
second half of April, 1704; and from other data (for which cf. Guhrauer,
Leibniz. Eine Bioyraphie, Bk. II., p. 282 and Anmerkungen z. zweiten Buche,
pp. 38-39; and Gerhardt's Introduction to the New Essays, ante, pp. 8, 9, and
notes) it is evident that the entire work was substantially completed in 1704,
though the revision of the French style, and possibly some minor additions or
alterations, occupied Leibnitz to a certain extent after this date.
In this connection it is to be noted that the date given, ante, p. 9, line 15,
1709, should be 1704 (cf. Gerhardt, Leibniz, philos. tichrtft., 3, 297, note *), and
that Gerhardt's remark, ante, p. 9: "On the other hand, he remarks, well-
nigh it seems in the opposite sense," etc., as well as that by the Translator,
ante, p. 101, note l,prope.fin.: " As Leibnitz was occupied . . . with the com
position and revision of his New Essays, from 1700 ... to 1709 and perhaps
later . . . possibly even as late as 1714 or 1716," should be modified accord
ingly. — TR.
1 Gerhardt's text reads: " Sur une veue actuelle des raisons, qui ont preva.lv
sur I'esprit, et il seroit tres difficile, meme a ceux, qui ont une memoire ad
mirable," etc. The words italicised above are not found in the texts of Raspe,
Erdmann, Jacques and Janet; and Janet restores the sense of " this incorrect
phrase " thus : "... Sur une vue actuelle des raisons, comme il ar?*ive chez
ceux qui ont une memoire admirable, capable de toujours retenir. ..."
Gerhardt's reading agrees with Locke's text, cf. Philos. Wks., Vol. 2, p. 271,
Bonn's ed., and is therefore to be preferred. — TR.
CH. xvi] ON HUMAN UNDERSTANDING 533
always to retain all the proofs which have compelled them to
a certain assent, and which sometimes might fill a volume on a
single question. It suffices that they have once examined the
matter minutely with sincerity and with care, and that they
have, so to speak, cast up the account. § 2. Without this men
must be very sceptical, or change their view at every moment,
in order to yield themselves to every man who, having exam
ined the question of late, offers them arguments which they
cannot at once wholly answer, for lack of memory or of appli
cation at leisure. § 3. It must be admitted that this often
makes men obstinate in error : but the fault is, not that they
rely upon their memory, but that they have badly judged be
fore. For often the remark that they have never thought
otherwise takes the place of an examination and of reason
with men. But ordinarily those who have least examined
their opinions hold them most tenaciously. Holding to what
one has seen is praiseworthy, but not always to what one has
believed, because some consideration may have been left behind
capable of overturning all. There is perhaps no one in the
world who has the leisure, patience, and means of assembling
all the proofs on both sides of the question upon which he
has his opinions in order to compare these proofs and safely
to conclude that nothing more remains for him to know for his
more ample instruction. But the care of our life and of our
more important interests cannot bear the delay, and it is abso
lutely necessary that our judgment be determined upon the
points when we are incapable of attaining to a certain knowl
edge.
Th. There is nothing but what is good and solid in what
you, sir, have just said. It would be desirable, however, for
men to have at certain junctures ivritlen abstracts (in form of
memoranda) of the reasons which have led them to an impor
tant opinion, which they are obliged often to justify after
wards to themselves or others. Besides, although in a matter
of justice it is not usually allowable to retract the judgments
which have been passed, and to revise the verdicts agreed
upon (otherwise there would necessarily be perpetual unrest,
which would be so much the more intolerable as the accounts
of things past cannot always be preserved), yet one is some
times allowed upon new light to sue for justice, and also to
534 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
obtain what is called restitutio in inlegrum1 contrary to the
decision that has been given. And likewise in our own
affairs, especially in matters very important, where it is still
allowable to embark or to put back, and where it is not preju
dicial to suspend their execution and to proceed bridle in
hand, the decisions of our minds based upon probabilities
should never so pass in rem judicatam, 2 as the jurisconsults call
it, i.e. to a settlement, that we may not be disposed to the
revision of the reasoning when new counter reasons of weight
present themselves. But when there is no more time for delib
eration, wre must follow the judgment we made with as much
firmness as if it were infallible, but not always with so much
strictness.3
§ 4. Ph. Since, then, men cannot avoid exposing themselves
to error in judgment and having different opinions, since they
cannot look at things from the same points of view, they must
maintain peace between themselves and the duties of humanity
amid this diversity of opinions without claiming that another
should promptly change a rooted opinion upon our objec
tions, especially if there is room for supposing that his
adversary acts from interest or ambition or from some other
private motive. Most frequently those who would impose
upon others the necessity of yielding to their opinions have
examined things with but little thoroughness. For those who
have entered beforehand sufficiently into the discussion to
extricate themselves from doubt are so few in number, and
find so little reason to condemn others, that nothing violent
is to be expected on their part.
Th. Really that which one has the most right to censure in
men is not their opinion, but their rash judgment in censuring
1 Cf. Paulus, Sententiarum, Lib. I., Tit. VII. 1. : "Integri restitutio est re-
dintegrandae rei vel causse actio. 2. Integri restitutionem praetor tribuit ex
his causis, quse per metum, dolum et status permutationem, et justum errorem,
et absentiam necessariam, et infirmitatem aetatis gesta esse dicuutur ; " also
Digest, Lib. XLII., Tit. I. 33.
'2 Cf. Digest, Lib. XLII., Tit. I. 1 : " Res jitdicata dicitur, qure finem con-
troversiam pronunciatione judicis aceipit : quod vel condemnation^ vel abso-
lutione contingit." — TR.
3 Janet cites as a parallel passage Descartes, Discours de la Methode, Pt.
III. : " Ma seconde niaxime etait d'etre le plus ferme et le plus resolu en mes
actions que je pourrais, et de ne suivre pas moins constamment les opinions
les plus douteuses lorsque je m'y serais une fois determine que si elles eussent
ete tres-assurees." — TR.
en. xvi] ON HUMAN UNDERSTANDING 535
that of others, as if it were necessary to be stupid or wicked
to judge differently from themselves; a condition of things
which, in the authors of these passions and hatreds who spread
them among the public, is the effect of a mind haughty arid
unfair, which loves to rule and cannot suffer contradiction.
Not that there is not, in truth, reason very often for censuring
the opinions of others, but it must be done in a spirit of fair
ness, and sympathy with human weakness. It is true that
we are right in taking precautions against bad doctrines,
which are influential upon manners and upon practical piety :
but we must not attribute them to people to their prejudice
without having good proofs of the same. If fairness wishes
to spare persons, piety demands the representation, where it is
fitting, of the bad effects of their dogmas when they are in
jurious, as those are which are contrary to the providence of a
perfectly wise, good, and just God, and contrary to that
immortality of souls which renders them susceptible of the
effects of his justice, not to speak of other opinions dangerous
as regards morality and the police. I know that excellent and
well-meaning men maintain that these theoretic opinions
have less influence upon practice than is thought, and I also
know that there are persons of an excellent disposition whom
these opinions will never make do anything unworthy of
themselves : as also those who have reached these errors by
speculation, are by nature wont to be farther removed from
the vices to which men in general are susceptible, besides the
fact that they are careful of the dignity of the sect in which
they are, as it were, chiefs ; and it may be said that Epicurus
and Spinoza, for example, have led a life wholly exemplary.
But these reasons cease most frequently in their disciples or
imitators, who, believing themselves released from the trouble
some fear of an overseeing Providence and of a menacing
future, give loose reins to their brutish passions, and turn
their mind to the seduction and corruption of others; and if
they are ambitious and of a disposition somewhat harsh, they
will be capable, for their pleasure or advancement, of setting
on fire the four corners of the earth, as I have known from the
character of some whom death has swept away. I find also
that similar opinions insinuating themselves little by little
into the minds of men of high life who rule others and upon
536 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
whom affairs depend, and slipping into the books in fashion,
dispose all things to the general revolution with which
Europe is threatened, and accomplish the destruction of what
still remains in the world of the generous sentiments of the
ancient Greeks and Romans, who preferred love of country
and of the public good, and regard for posterity to fortune,
and even to life. These public spirits, as the English call
them, are fast diminishing, and are no longer in fashion ; and
they will dimmish still faster when they are no longer sus
tained by the good morality and true religion which even
natural reason teaches us. The best of the opposite character
who are beginning to rule have no other principle than that they
call honor. But the mark of the honest man and of the man of
honor with them is only to do no baseness as they understand
it. And if for the sake of power or through caprice anyone
poured forth a deluge of blood, if he turned every sense upside
down, that would be counted as nothing, and a Herostratus 1 of
the ancients or a Don Juan in the " Festin de Pierre " 2 would
pass for a hero. Boldly they scoff at the love of country, they
ridicule those who care for the public, and when any well-mean
ing man speaks of what will become of posterity, they reply:
we shall see when the time comes. But these persons will pos
sibly experience themselves the evils they think reserved for
others. If, however, this disease of an epidemic mind whose bad
effects begin to be visible is corrected, these evils will perhaps
be prevented; but if it goes on increasing, Providence will
correct men by the revolution itself wnich must spring there
from: for whatever may happen, everything will always turn
out for the better in general at the end of the account, although
that ought not and cannot happen without the punishment of
those who have contributed even to the good by their bad acts.
But I return from a digression into which the consideration of
truthful opinions and of the right of censuring them has led me.
1 Herostratus, an Ephesian, who, for the sake of making his name famous,
as he himself confessed on being put to torture, set fire to the temple of Ar
temis at Ephesus, on the night in which Alexander the Great was born,
356 B.C. — TR.
2 The Don Juan ou le Festin de Pierre, 1665, a comedy of Moliere, 1622-
1673, the principal character of which is Don Juan. The play, written in
prose, was versified in 1677, at the request of Moliere's widow, by Thomas
Corneille, 1(525-1709. — TR.
CH. xvi] ON HUMAN UNDERSTANDING 537
Now as in theology censures go very much farther than else
where, and as those who lay great stress upon their orthodoxy,
often condemn their adversaries, to whom those in the same
party who are called syncretists by their adversaries are
opposed, this opinion has caused civil wars to spring up
between the rigid and condescending in one and the same
party. But, as to refuse eternal salvation to those who are of
another opinion is to encroach upon the rights of God, the
wisest of those who condemn, only indicate the peril in which
they think they see erring souls, and leave to the peculiar
mercy of God those whose wickedness does not render them
incapable of profiting therefrom, and on their part believe
themselves obliged to make all imaginable efforts to withdraw
them from a condition so dangerous. If these persons who
thus judge of the perils of others have come to this opinion
after a suitable examination and there are no means of dis
abusing them of it, their conduct cannot be censured so long
as they use only fair means. But as soon as they go farther,
they violate the laws of equity. For they should consider
that others persuaded like themselves have an equal right to
maintain their views, and even to spread them if they think
them important. Opinions must be excepted which teach
crimes that should not be allowed, and which it is right to
suppress by stringent means, if it should be true, indeed, that
he who maintains them cannot be rid of them; 1 as it is right
to destroy even a poisonous animal, wholly innocent as it is.
But I speak of suppressing the sect and not men, since we
can prevent them from doing harm and dogmatising.
§ 5. Ph. To return to the ground and degrees of assent, it
is proper to remark that propositions are of two kinds. Some
are of fact, and, depending upon observation, may be based upon
human testimony ; others are speculative, and, regarding things
which our senses could not discover, are incapable of similar
testimony. § 6. When a particular fact is in conformity with
our constant observations, and with the uniform report of
others, we rest upon it as firmly as if it were certain knowl-
1 Gerhardt reads: " ne pent point s'en defaire." Evdmann, Jacques and
Janet read: " ne peut point s'en faire," and Janet in his note says : "supply
'd'autres.' " "With this reading the meaning is: " cannot procure for himself
others." — TR.
538 LEIBNITZ'S CRITIQUE OF LOCKE [UK. IT
edge, and where it is in conformity with the testimony of all
men, in all ages, so far as can be known, it is the first and
highest degree of probability; for example, that fire warms,
that iron sinks to the bottom of the water. Our belief built
upon such foundations rises to assurance. § 7. In the second
place, all historians relate that such an one has preferred his
individual interest to that of the public, and as it has always
been observed that this is the custom of the majority of men,
the assent I give to these histories is confidence. § 8. Thirdly,
when there is nothing either for or against it in the nature of
things, a fact, vouched for by the testimony of unsuspected
people, for example, that Julius Caesar lived, is received with
a firm belief. § 9. But when the testimony is found contrary
to the ordinary course of nature or the witnesses vary among
themselves, the degrees of probability may vary infinitely,
whence arise these degrees which we call belief, conjecture,
doubt i uncertainty, distrust; and there it is that exactness is
necessary to form a right judgment and to proportion our
assent to the degrees of probability.
Th. Jurisconsults in treating of proofs, presumptions, con
jectures, and indices, have said a number of good things on
this subject, and have gone into some considerable detail.
They begin with notoriety, in which there is no need of proof.
Afterwards they come to complete proofs, or those which pass
as such, upon which they pronounce sentence, at least, in a
civil process, but upon which in some places they are more
reserved in a criminal process; and they are not wrong in
demanding in such case proofs more than complete, and espe
cially as regards what is called corpus delicti, according to the
nature of the act. There are then proofs more than complete,
and there are also ordinary complete, proofs. Then there are
presumptions, which pass provisionally as complete proofs,
i.e. so long as the contrary is not proved. There are proofs
more than half complete (to speak precisely), in which the one
who relies upon them is allowed to swear to make them good
(the juramentum suppletoriuni) ; there are others less than half
complete, where wholly to the contrary the oath is adminis
tered to him who denies the act, to purge himself (the jura
mentum purgationis) . Beyond this there are many degrees
of conjectures and indices. Particularly in a criminal process
CH. xvi] ON HUMAN UNDERSTANDING 539
there are indices (ad torturam) to proceed to the torture, which
itself has its degrees indicated by the formulas of arrest;
there are indices (ad terrendain) sufficient to show the instru
ments of torture and to prepare things as if they intended to
come to it. There are some (ad capturam) to make sure of
a suspected man; and (ad inquirendum) to make inquiries
secretly and without noise. And these differences may be of
use also on other similar occasions. The entire form of judi
cial procedure is nothing else in fact than a species of logic
applied to questions of law. Physicians also have a number
of degrees and differences in their signs and indications which
may be seen among them. The mathematicians of our times
have begun to calculate chances upon the occasion of games.
Chevalier de Mere,1 whose "Agremens" and other works have
been printed, a man of penetrating mind who was both a
player and a philosopher, gave them an opportunity by form
ing questions regarding the profits in order to know how much
the game would be worth, if interrupted at such or such a
stage. In this way he induced Pascal, his friend, to examine
these things a little. The question made a stir and gave
Huygens the opportunity to produce his treatise "de Alea."2
1 (_{f. ante, p. 213, note 2; also Response (Re'plique) aux reflexions contenues
dans la seconde Edition du IHctionnaire Critique de M. Bayle, Gerhardt, 4,
570, Erdmann, 190, Janet, 2, 593, Dutens, 2, Ft. I., 92. Antoine Gombault,
chevalier de Mere, c. 1010-1684, was erroneously confounded with a Georges
Brossin, chevalier de Mere, belonging to another family, by all biographers
since Moreri, until the special researches of M. de Bremont d'Ars proved the
error and assigned him his right name. He had an inordinately exalted idea
of his own importance and attainments, especially in mathematics. His
Ar/re'ments, discours de M. le chevalier de Mere a Mme **, appeared in 1(577,
12mo, and in the collected edition of all his works, entitled (Euvres du chevalier
de Mere, Amsterdam, 1092, 2 vols., 12mo. A volume of (Enures post/mines,
12mo, appeared at Paris, 1700, and again at The Hague, 1701. For further
account of him, c/. Larousse, Grande Diet. Univ. de XIXme Siecle, Vol. 11, p.
72.— TR.
'2 (Jf. ante, p. 150, note 3. Huygens' De ratiociniis in alese ludo, dated The
Hague, 1057, is found in F. van Schooten, Exercitat. math. lib.V., pp. 514-539,
Lugd. Bat. 1657, 4to. It was written by Huygens in Dutch and translated into
Latin by Schooten. There are two English translations, one attributed to
Motte, but probably by Arbuthnot ; the other by W. Brown. Cf. I. Todhunter,
Hist, of the ^fath. Theory of Probability, pp. 22-23, Cambridge and London,
Macmillan & Co., 1865. Leibnitz, Miscellan. Leibnit., No. CXIIL, c/. Dutens,
0, Ft. I., 318, says of it: "Christiani Hugenii ratiocinia de lusu alese, Franc.
Schotenii scriptis mathematicis adjecta, sunt elegans specimen ratiocinations
de gradibus probabilitatis."
Spinoza also discussed the calculation of probabilities in games of chance,
540 LEIBNITZ'S CRITIQUE OF LOCKE [UK. iv
Other learned men entered into the subject. Some principles
were established of which the Pensioner De Witt also availed
himself in a brief discourse printed in Dutch on annuities.1
The foundation on which they have built goes back to the
prosthaphceresis,2 i.e. the taking of an arithmetical mean be
tween several equally receivable suppositions. Our peasants
also have made use of it for a long time according to their
natural mathematics. For example, when some inheritance or
land is to be sold, they form three bodies of appraisers; these
bodies are called Schurzen in Low Saxon, and each body makes
an estimate of the property in question. Suppose, then, that
the first estimates its value to be 1000 crowns, the second
1400, the third 1500; the sum of these three estimates is
taken, viz. 3900, and because there were three bodies, the
third, i.e. 1300, is taken as the mean value asked for; or
rather, they take the sum of the third part of each estimate
which is the same thing. This is the axiom : oequalibus
cequalia, equal suppositions must have equal consideration.
But when the suppositions are unequal they compare them
with each other. Suppose, for example, that with two
dice, the one ought to win if it makes 7 points, the
other if it makes 9, the question is asked what proportion
obtains between their probabilities of winning? I reply that
the probability of the last is worth only two-thirds of the
in a letter to Jan van der Meer. Cf. Epistola No. 38 (formerly 43), Spinoza,
Opera, ed. Van Vloten and Land, 2, 145-149 (in Latin and Dutch) : Spinoza's
Brief ivechxel, in J. H. v. Kirchmann's Philos. Bibliothek, Vol. 4fi, pp. 145-
147. — TR.
1 Cf. ante, p. 426, note 2. John De Witt appears to have been " the first to
apply scientific principles to the calculations connected with annuities, which
are analogous to those connected with assurances." His report on this sub
ject was presented to the States General, July 30, 1(571. It was entitled De
vardye van de Uf-renten na proportie van de los-renten, and appeared at La
Haye, 1(571. An abstract of it, showing exactly how De Witt reasoned on the
subject, will be found in M. Nicolas Struyck, Inleiding tot het alae>n°ine geo
graphy, etc., p. 34.", Amsterdam, 1740, 4to, and an English translation of the
tract is printed in Contributions to the Hist, of I insurance by Frederick
Hendriks in the "Assurance Magazine," Vol. 2 (1S52), p. 231. For some
remarks on De Witt's hypothesis as to the rate of mortality, cf. the same vol.,
p. 393. — TR.
2 Prosthaphaeresis — 7rpo0-0a<Wpeo-t? — = a previous subtraction. The term
here signifies " the fundamental principle for the ascertainment of the degree
of probability which requires us to take the arithmetical mean of the existing
suppositions estimated according to their relative value." — TR.
CH. xvi] ON HUMAN UNDERSTANDING 541
probability of the first, for the first can make 7 in three ways
with two dice, viz. : by 1 and 6, or 2 and 5, or 3 and 4; and
the other can make 9 in two ways only, by throwing 3 and 6,
or 4 and o; and all these methods are equally possible.
Then the probabilities, which are as the numbers of equal
possibilities, will be as 3 to 2, or as 1 to f . I have more than
once said that a new 'kind of logic would be required which
would treat of the degrees of probability, since Aristotle in
his "Topics" has done nothing less than this, and has con
tented himself with putting in a certain order certain popular
rules distributed according to the common topics, which may
be of use on some occasion where the question concerns the
amplification of the discourse and the giving to it probability
without putting it to the trouble of furnishing us a necessary
balance for weighing probabilities and forming thereupon a
solid judgment.1 It would be well for him who should treat
of this matter to pursue the examination of games of chance;
and in general I wish that some skilful mathematician would
produce an ample work with full details and thoroughly
reasoned upon all sorts of games, which would be very useful
in perfecting the art of invention, the human mind appearing
to better advantage in games than in the most serious matters.
§ 10. Ph. The law of England observes this rule, that the
copy of an act received as authentic by witnesses is a good
proof, but the copy of a copy, however attested, and by wit
nesses the most credible, is never admitted as a proof in a
trial. I have never yet heard any one censure this wise pre
caution. This observation at least may be drawn from it,
that testimony has less force in proportion as it is farther
removed from the original truth which is in the thing itself;
while among certain peoples use is made of it in a directly
contrary manner, opinions acquiring force as they grow older,
and what would not at all have appeared probable a thousand
years ago to a reasonable man a contemporary of the one who
first certified it, passes at present as certain because many
have related it upon his testimony.
Tli. Historical critics have great regard for contemporary
witnesses of things : but a contemporary even merits belief
chiefly as regards public events only ; but when he speaks of
1 Cf. ante, p. 417, note 3. — TR.
542 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
motives, secrets, hidden forces, and things which may be dis
puted, as, for example, poisonings, assassinations, we acquaint
ourselves with what many have believed. Procopius is very
credible when he speaks of the war of Belisarius against the
Vandals and the Goths, but when he retails horrible scandals
against the Empress Theodora in his " Anecdotes," he may
believe them who will.1 Generally, we should be very re
served in believing satires ; we see some published in our times
which, although wholly improbable, have nevertheless been
greedily swallowed by the ignorant. And some day perhaps
it will be said : Is it possible that one would have dared to
publish these things at that time, if there had been any appar
ent foundation for them ? But if this statement is some day
made, the judgment will be a very erroneous one. The world,
however, is inclined to indulge in satire ; and, to quote but
one example, the late Mr. Maurier, the son,2 having published,
from some caprice, in his memoirs printed some years since,
certain things wholly without foundation against the incom
parable Hugo Grotius, ambassador from Sweden to France,
stirred apparently by some unknown circumstance against the
memory of this illustrious friend of his father, I have noticed
that many authors have repeated them from envy, although
the negotiations and letters of this great man sufficiently
make known the contrary. We have emancipated ourselves
indeed from writing romances in history, and he who produced
the last life of Cromwell thought that in order to enliven the
subject he was allowed, in speaking of the life, still private,
of this clever usurper, to make him travel in France, where
he follows him into the public houses of Paris as if he had
1 For critical discussion of the authorship of the Td '\vexSoTa — Anecdota
or Historia Arcana — of Procopius, and of the credibility of its contents, cf.
J. H. Reinkens, Anecdota sintne scripta a Procopio Csesariensi inquiritur,
Breslau. 1858, who denies, and F. Dahn, Prokopius von Casarea, Berlin, 18(>5,
who affirms, that Procopius is the author. Prof. James Bryce gives a brief
account and estimate of the work in his article on "Procopius," in the
Encyclop. Brit. 9th ed. Cf. also M. Debidour, Thesis, 1877, who tries to make
out the best case he can for Theodora, and Prof. Bryce in the " Contemporary
Review," Feb. 1885. — TR.
2 Louis Aubery du Maurier, the historian, died 1087, was the son of
Benjamin Aubery, an ambassador from France to Holland, and published
Memoires pour servir a I'Histoire de Hollande, 1(580, Me moires de Hamburg,
de Lubeck, de Holsiein, etc. Leibnitz refers to him in his letter to Bierling,
Oct. 24, 1709, Gerhardt, 7, 487. —TR.
CH. xvi ] ON HUMAN UNDERSTANDING 540
been his master.1 But it appears by the history of Cromwell
written by Carrington, a well-informed man, and dedicated
to his son Kichard when he acted the part of the Pro.
tector, that Cromwell never went out of the British Isles.
Detail especially is uncertain. There are almost no good
accounts of battles ; the majority of those of Titus Livius
appear to be imaginary, as well as those of Quintus Curtius.
It would be necessary to have on both sides the accounts of
exact and capable men, who indeed would draw up plans of
them like those which the Count of Dahlberg, who had already
served with distinction under the King of Sweden, Charles
Gustavus, and who, being Governor-General of Livonia, re
cently defended Riga, has had engraved touching the actions
and battles of this prince. We must not, however, at once
decry a good historian at a word from some prince or minister
who has exclaimed against him on some occasion, or in regard
to some subject not to his taste or wherein there really is per
haps some fault. The story is told that Charles the Fifth,
wishing to have something of Sleidan2 read, said: "Bring me
my story-teller (menteur)," and that Carlowitz, a Saxon gentle
man, of good repute at that time, said that the history of Slei
dan destroyed in his mind all the good opinion he had had of
the ancient histories. That statement, I say, will have no force
in the minds of well-informed persons in overthrowing the
authority of the history of Sleidan, the best part of which is
a series of the public acts of the Diets and Assemblies, and
of the writings authorized by the princes. And if there re
mained the least scruple regarding it, it has just been removed
by the excellent history of my distinguished friend, the late
Mr. Von Seckendorf3 (in which I cannot, however, refrain
1 Leibnitz here refers, according to Schaarschmidt, to Jas. Heath's Flaqel-
lum; or the Life and Death, Birth and Burial of Oliver, the late Usurper,
London, 1663, 8vo. In this book the Protector is generously slandered and
abused. S. Carrington's The Hist, of the Life and Death of Oliver Croimoell,
London, 1659, 8vo, is a panegyric, in which Cromwell is compared, among
others, with Alexander the Great. An abridgment of Heath's book may be
found in the " Harleian Miscellany," 1,279, ed. Park. It may be added that
" the earliest lives of Cromwell were either brief chronicles of the chief events
of his life or were panegyrics." — TR.
2 Cf. ante, p. 114, note 1. — TR.
3 Veit Ludwig von Seckendorf, 1626-1692, a distinguished German scholar
and statesman, whose Conimeutarius liistoricus et apoloyeticus de Lutheran-
544 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
from disapproving the term " Lutheranism " on the title-page,
which a bad custom has authorized in Saxony), wherein the
majority of the statements are justified by extracts from an
immense number of pieces, drawn from the Saxon archives
which he had at his disposal, although the Bishop of Meaux,
who contested their validity, and to whom I sent it, merely
replied to me that this book is horribly prolix ; but I could
wish that it were twice as large on the same scale. The more
ample it is, the more hold it must give, since one has only to
choose his passages ; besides, there are some esteemed histori
cal works which are much greater. For the rest, we do not
always despise authors posterior to times of which they
speak when what they relate is apparently otherwise. Some
times, also, it happens that they preserve some most ancient
pieces. For example, there has been doubt as to what family
Suibert, Bishop of Bainberg, since Pope under the name of
Clement II., belonged. An anonymous author of the history
of Brunswick, who lived in the fourteenth century, named his
family, and some persons learned in our history desired to pay
no regard whatever to it; but I have had a chronicle much
more ancient, not yet printed, in which the same statement is
made with more details, from which it appears that he be
longed to the family of the ancient allodial seigniors of Horn-
bourg (not far from Wolfenbuttel), the territory of which was
given by the last owner to the cathedral church of Halber-
stadt.
. § 11. Ph. I do not wish you to think that I desired to lessen
the authority and use of history by my remark. It is .from
this source that we receive with a convincing evidence a large
ismo sive de Reformation?, Leipzig, 1002, 3 vols., fol., occasioned by and
directed against the L'Histoire clu Lutheran/sine, Paris, 16SO, of the Jesuit
Maimbourg, is his most important work, and a rich storehouse of authentic
materials for the history of the reformation from 1517-1547, drawn from
locuments contained in the Saxon archives, the writings of the reformers and
•i'aeir contemporaries, accompanied by a polemical and historical commentary.
it is the work of an able, philosophic mind, with scarcely a trace of the secta-
vian spirit. Leibnitz gives a brief account and estimate of the book in his
letters to Bossuet, Jan. 8-18, and April 8-18, 1692 (c/. Foncher de Careil,
<E'ivi'ps de Leibniz, \, 228, 275, Dutens, Leibnlt. op. om., 1. 523-4, 530-531). It
is also referred to in Bossuet's letters to Leibnitz, Jan. 10, 1692 (F. 1, 22) >, D. 1,
522), March 26 or May 26, 1692 (F. 1, 253), and Leibnitz to Bossuet, without
dates (F. 1, 223, 254-255). For further remarks of Leibnitz concerning it, cf.
Dutens, 5, 90, 93, 566. — TR.
CH. xvi] ON HUMAN UNDERSTANDING 545
part of ,our useful truths. I see nothing more valuable than
the records of antiquity remaining to us, and I wish we had
more of them, and less corrupted. But it is always true that
no copy raises itself higher than the certainty of its first
original.
Tli. It is certain, that when we have a single ancient author
as the authority for a fact, all those who have copied him add
no weight thereto, or rather should be reckoned as nothing.. It
should be wholly as if what they said belonged to the number,
TO>V tt:ra£ Aeyoju.eVa>v, of things which have been said only once,
a collection of which Menage1 wished to make. Moreover, to
day, if a hundred thousand petty writers should repeat the
slanders of Bolsec 2 (for example), a man of judgment would
value it no more than the noise of goslings. Jurisconsults
have written de fide liistorica ; but the subject merits a more
exact research, and some of these gentlemen have been too
indulgent. As for that which is of great antiquity, some of
the most noted facts are doubtful. Clever people have doubted,
with reason, whether Romulus was the first founder of the
city of Home. There is dispute about the death of Cyrus, and
besides, the discrepancy between Herodotus and Ctesias has
spread doubt upon the history of the Assyrians, Babylonians,
and Persians. That of Nebuchadnezzar, of Judith, and even
of the Ahasuerus of Esther suffer from great difficulties. The
Romans, when speaking of the gold of Toulouse, contradict
the story of the defeat of the Gauls by Camillas. Above all,
the particular and private history of peoples is without credit,
unless it is taken from very ancient originals, and is suf
ficiently in conformity with public history. This is why the
1 Of. ante, p. ;>50, note 1. — TR.
'2 Jerome Henries Bolsec, born at Paris, died lo'So, at Lyons, was a Carmel
ite of Paris, who forsook his order, became a Protestant, fled to Italy and
thence to Geneva, where he set up as a physician, but not meeting with the
success he desired, gave himself up to theology, discoursed publicly on the
doctrine of Predestination, advocating the views of Pelagius, and thus incur
ring the censure of Calvin, was imprisoned and then banished by the Senate of
Geneva, Dec. 29, 1551. He went thence to Bern, whither Calvin pursued him.
These persecutions developed in him a violent hatred towards Calvin, which,
after his return to the Catholic faith, he vented in his L'Histoire de la vie,
m<£iirs, act<jf>, doctrine et mart de Jean Calvin, Paris, 1577, 8vo. He also pub
lished a similar work, L'Histoire de la vie, mwurs, doctrine et deportements de-
Theodore de Beze, Paris, 1580, 8vo. Both works are merely pamphlets, with
no historical authority. — TR.
2 N
546 LEIBNITZ'S CRITIQUE OF LOCKE [BK iv
stories told us of the ancient German, Gallic, British, Scotch,
Polish, and other kings pass with reason as fabulous and
made up. Trebeta, son of Ninus, founder of Treves, Bru
tus, ancestor of the Britons, or Britains, are as real as the
Amadis. The tales taken from certain story-tellers, which
Trithemius.1 Aventin,2 and even Albinus3 and Sifrid Petri4
have taken the liberty to tell of the ancient princes of the
Franks, Boii, Saxons, Frisians ; and what Saxo Gramaticus
and the Edda tell us of the remote antiquities of the north,
cannot have more authority than what Kadlubko,5 the first
Polish historian, says of one of their kings, a son-in-law of
Julius Caesar. But when the histories of different peoples
agree in instances where there is no appearance that one has
copied another, it is a great sign of their truth. Such is the
1 Johann Trithemius, 1462-1516, abbot of Spanheim, whose Compendium,
siv° br evict r ium primi vQluminisannalium,sive historiarum, de origins rerum
et gentis Francorum appeared at Mainz, 1515, reprinted, Paris, 1589. Leib
nitz speaks of him in his Introd. in collectionem Scriptorum Histor. Bruns-
vicensi inservientium, Dutens, 4, Pt. II., 4, 5. For an account of him, cf.
Miehaud, Biog. Univ. Vol. 46, pp. 551-559. — TR.
2 Johann Thurmayr Aventinus, 1466-1534, author of Annales Boionnn.
His history, the materials of which were drawn from authentic sources, was
finished in 152S, and published "with some important omissions" of passages
adverse to the Roman Catholics by Zeigler in 1554. The omitted passages were
afterwards restored by Nicolas Cisner in the Basle ed., 1580. Leibnitz mentions
him in his Introd. in col. Script. Histor. Brunsvic., Dutens, 4, Pt. II. ,4. — TR.
3 Alcuin, — Latin, Alcuinus or Albinus Flaccus, — c. 735-804, the instructor
of Charlemagne, whose collected works, containing among other things some
historical treatises, were first published by And. Duchesne, Paris, 1617, 1 vol.,
fol., and afterwards by Froben, Alcuini opera, post editionem ab And.Querce-
tano curatoin, dc nnvo collata, emendata, aucta et illustrata, 2 vols., fol.,
Ratisbon, 1777. Migne, Patrol., Yols. 100, 101, is a reprint of this ed. — TR.
4 Sifrid or Suffrid Petri, 1527-1597, a Dutch philologist of great learning,
but deficient in critical ability and taste, was Professor of Latin and Greek in
the University of Erfurt, 1557, of Law at Cologne, 1577, and of Canon Law at
Louvain and Cologne, 1585. He was the historiographer of the States of Fries-
land, and published De Frisiorum antiqttitate et origine lib. III., Cologne,
1590; l)e Scriptoribus Frisise decades XVI. et semis, Cologne, 1593. His
Ilistoria veterum episcoporum Ultrajectinse sedis et comilum Hollandise,
appeared at Francker, 1612. — TR.
5 Vincent Kadlubek or Kodlubko, 1161-1223, bishop of Cracow, a Latin
chronicler of the early history of Poland, whose Historia Polonica, Do-
bromiel, 1612, 12mo, written with spirit, but in a barbarous style, throws
much light on the events of his own time, but must be received with caution,
as regards the early period, since he treated the early legendary stories, many
of which closely resemble the Scandinavian sagas, as genuine history. The
work is in four books and extends to the year 1202, and is true and faithful
in relating events in Poland in the llth and 12th centuries. — TR.
CH. xvi] ON HUMAN UNDERSTANDING 547
accord of Herodotus with the history of the Old Testament in
many things, for example, when he speaks l of the battle of
Megiddo between the king of Egypt, and the Syrians of Pales
tine, i.e. the Jews, in which, according to the testimony of
the sacred history we have of the Hebrews, King Josias was
mortally wounded. The consent of the Arabic, Persian, and
Turkish historians with the Greeks, Romans, and other occi
dentals gives pleasure to those who seek for facts ; as also
the testimony which the medals and superscriptions, remain
ing from antiquity, render to the books which have come down
from the ancients to us and which are, in reality, copies of
copies. We must wait for what we shall yet learn of the
history of China, until we are in a better condition to judge
of it, and until it shall bear its credibility with itself. The
use of history consists principally in the pleasure there is in
knowing origins, in the justice rendered to the men who have
deserved well of other men, in the establishment of historical
criticism, and especially of sacred history, which supports the
foundations of revelation, and (putting also aside the geneal
ogies and laws of princes and powers) in the useful teachings
which the examples furnish us. I do not despise the thorough
examination of antiquities, even to the smallest trifles ; for
sometimes the knowledge which the critics draw from them
may be of use in more important matters. I consent, for ex
ample, to the writing even of the entire history of clothing
and of the tailor's art, from the garments of the Hebrew priests,
or, if you please, from the peltries which God gave to the first
bride and bridegroom at their departure from Paradise, to the
top-knots and furbelows of our time, and to the union there
with of all that can be drawn from ancient sculptures and
from paintings also made some centuries after. I will furnish
indeed, if any one desires it, the memoirs of a man of Augs
burg of the past century, who is described with all the clothes
which he wore from his infancy up to the age of 63 years. I
do not know who told me that the late Duke of Aumont,2 a
1 Qf. Herodotus II. 159, and notes of Bahr and Rawlinson on the passage.
— TR.
2 Louis-Marie-Victor d'Aumont, 1682-1704, a French scholar, numismatist,
and " brigadier du roi" under Louis XIV. in the Low Countries, contributed
much to the progress of the knowledge of medals, and was a member of the
" Ac.M'lemie des inscriptions et Belles-Lettres." — TR.
548 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
great connoisseur of fine antiquities, had a similar curiosity.
This may perhaps be of use in distinguishing the legitimate
monuments from those which are not so, not to speak of other
uses. And since men are allowed to play, they will still
further be allowed to divert themselves with these kinds of
work, if their essential duties do not suffer thereby. But I
wish there might be some persons who would devote them
selves preferably to drawing from history that which is more
useful,- as the extraordinary examples of virtue, remarks upon
the conveniences of life, stratagems of politics and of war.
And I wish that a kind of universal history were written
which should indicate only such things, and some few others
of more consequence ; for sometimes one reads an extensive
historical work, learned, well-written, suited also to the end
of the author, and excellent of its kind, but which contains
little useful instruction, by which I do not mean here simple
morality, with which the " Theatrum vitas humanse" 1 and other
such florileges* are rilled, but skill and knowledge of which
everybody would not think in case of need. I wish also that
an infinite number of things of this nature, by which we might
profit, might be drawn from books of travel, and be arranged
according to the order of the subjects. But it is astonishing
that while so many useful things remain to be done, men
amuse themselves almost always with what is already done,
or with purely useless things, or at least with what is the
least important, and I see little remedy therefor until the
public is more concerned about them in more tranquil times.
§ 12. Ph. Your digressions give pleasure and profit. But
from the probabilities of facts, let us come to those of opinions
concerning things which do not fall under the senses. Such
things are incapable of any testimony, for example, the exist
ence and 2 nature of spirits, angels, demons, etc., the material
substances which are in the planets and other mansions8 of
1 Theodore Zwinger, 1533-1588, a celebrated Swiss physician, whose Thea-
tnnn vitfB humanse, " a vast compilation of historical facts and anecdotes, and
of curious and piquant observations," in preparing which he availed himself
of the materials which his father-in-law, Lycosthenes [Conrad Wolff hart],
1518-15(51, had collected and asked him to set in order, appeared at Basle,
1565-1004, 5 vols., fol. — TR.
2 Gerhardt reads: " de," a Ms. or typographical error; Erdmann, Jacques,
and Janet have " et." — TR.
3 Locke's word, Philos. Works, Vol. 2, p. 279 (Bonn's ed.).— TR.
CH. xvi] ON HUMAN UNDERSTANDING 549
this vast universe ; finally, upon the mode of operation of the
majority of the works of nature, and of all these things \ve
can have merely conjectures, wherein analogy1 is the great
rule of probability. For being incapable of attestation, they
can appear probable only so far as they agree more or less
with established truths. As violent friction of two bodies
produces heat and even tire, as the refractions of transparent
bodies produce the appearance of colors, we think that jire
consists in a violent agitation of the imperceptible parts, and
that colors also, whose origin we do not see, come from a simi
lar refraction; and finding that there is a gradual connection
in all the p.irts of the creation that may be subject to human
observation, without any considerable gap between any two,
we have every reason to think that things rise also towards
perfection gradually and by insensible degrees.2 It is difficult
to say where the sensible and the rational begin, and what is
the lowest degree of living things ; it is like the increase or
diminution of quantity in a regular cone. The difference is
exceeding great between certain men and certain animals;
but if we wish to compare the understanding and capacity of
certain men and certain brutes, we shall find so little differ
ence, that it will be very difficult to assert that the under
standing of these men is clearer or more extended than that
of these brutes. When, therefore, we observe such an insensi
ble gradation between the parts of creation from man to the
lowest parts beneath him, the rule of analogy makes us regard
it as probable that there is a parallel gradation in the things
above us and beyond the sphere of our observation, and this kind
of probability is the broad foundation of rational hypotheses.3
1 In the case of natural phenomena beyond the reach of the senses, analogy
is the great rule of probability, the reasoning in general being hypothetical
only, and the force and certainty of the conclusion therefrom being directly
proportional to the reality and degree of the resemblance or similarity of the
phenomena. Since Locke's and Leibnitz's day, great advance has been made
in our knowledge of the nature of the materials existing in the various heav
enly bodies, chiefly through the aid of the spectroscope and spectral analysis,
not only strengthening and increasing the measure of probability in the appli
cation of the conclusion from analogy to the conjectured conditions of other
worlds, but in some cases and to a certain extent giving us well accredited
positive knowledge in regard to their constitution. — TR.
2 Of. A. C. Fraser, Locke's Essay Concerning Human Understanding, Vol.
2, p. 380, note 2. Oxford, Clarendon Press, 1894. —TR.
3 The probable conclusion from analogy is a rational hypothesis, whose
550 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
Th. It is upon the ground of this analogy that Huygeris, in
his " Cosmotheoros," l judges that the condition of the other
principal planets is quite similar to ours, excepting the differ
ence which their different distance from the sun must cause :
and Fontenelle,2 who had already before published his conver
sations full of wit and knowledge on the plurality of worlds,
hypothetical character consists in the fact that it is not a completely exhaus
tive induction or a mathematical demonstration from the given data, therefore
still problematical, and whose rationality consists in the fact that no known
reason exists against the assumed instance, but on the contrary the analogy
itself directly furnishes occasion for a provisional consideration of, if not a
belief in, the hypothesis. — TR.
1 Cf. ante, p. 150, note 3. Huygen's Cosmotheoros, sive de terris cwlestibus
earumque ornatu conjecture — a speculation concerning the inhabitants of
the planets, and the last work of the great physicist and mathematician —
appeared posthumously, at the Hague, 1(598, and in a German trans., Leipzig,
1703, just before Leibnitz wrote Bk. IV. of the New Essays, and in an English
trans., entitled, The Celestial World discovered; or Conjectures concerning
the Inhabitants, Plants, and Productions of the Worlds in the Planets, Lon
don, 1699, 8vo ; Conjectures concerning the Planetary Worlds, Glasgow, 1727,
12mo. The work is found in Huygeus, Opera Omnia, Leyden, 1821, 2 vols.,
Vol. 1, pp. 641-722. — TR.
'2 Bernard le Bovier de Fontenelle, 1657-1757, a litterateur rather than a
philosopher, who, nevertheless, according to Janet, " belongs to the history of
philosophy, through the spirit of inquiry and criticism which animates his
works," attempted, and successfully, in his Entretlens sur la plurality des
niondes, Paris, 1686, 12mo (a sixth Entretien was added in the Paris ed. of
1687, according to Brunet) to popularize the astronomical theories and doc
trines of Copernicus and Descartes. The work is a fine illustration of the
possibility of making science, without ceasing to be scientific, intelligible and
interesting to the men of the world. Fontenelle became a member of the
" Academie Francaise " in 1691, and, on the revival of the "Academic des Sci
ences de Paris " in 1699, was nominated its perpetual secretary, and continued
in that office for fifty-eight years, publishing each year a volume of the Histoire
of this Academic, containing clear and orderly arranged extracts from or anal
yses of the papers read before the Academie, often accompanied with new and
profound views of his own, together with Eloges of the members dying in
each year, among which is the Eloge de Leibniz, "a masterpiece," found in
L' Histoire de I' Academie Roy ale des Sciences de Paris, annee 1716; in Vol. 3,
1722, of the collection of these Eloges, 69 in number, entitled Histoire du
renouvellement de I' Academie Roy ale des Sciences en 1699, et Eloges historiques
d°s Acadeiniciens morts depuis ce temps-la, 3 vols., Paris, 1708-1722; in
(Euvres de Fontenelle, 3 vols., La Haye, 1728-29, Vol. 3, pp. 232-259; new ed.,
11 vols., Paris, 1766, Vol. 5, pp. 447-506; and in F. Bouillier, Eloges de Fon
tenelle avec une Introd. et des Notes, Paris, 1883, pp. 103-134; cf. also Jacques,
(Euvres de Leibniz, Vol. 2, pp. i-xxiv, Dutens, Leibnit. op. om., Vol. 1, pp.
xix-liii.
The Entretiens sur la pluralite des mondes is found in (Euvres de Fon-
tenelle, La Haye, 1728-1729, Vol. 1, pp. 149-234; new ed., Paris, 1766, Vol. 2,
pp. 1-190; there is a German trans, by Gottsched, 1751, Eng. trans, by Glan-
vill, London, 1688, 1768, by A. Belm and others, London, 1801, and from the
CH. xvi] ON HUMAN UNDERSTANDING 551
has said some pretty things thereupon, and has discovered the
art of enlivening a difficult1 subject. He would say, as it
were, that a harlequin in the empire of the moon is altogether
what it is here. It is true that we judge in a wholly different
way of moons (which are satellites merely) than of the princi
pal planets. Kepler2 has left a little book which contains an
ingenious story upon the condition of the moon, and an Eng
lishman,3 an homme d9 esprit, has published the humorous de
scription of a Spaniard (of his own invention) whom some birds
of passage transported to the moon, not to mention Cyrano,4
who since went to find this Spaniard. Some clever men, wish
ing to present a beautiful picture of the other life, conduct
very happy souls from world to world ; and our imagination
finds therein a part of the agreeable occupations which may be
ascribed to genii. But however it may strive, I doubt if it
can attain its object, because of the great interval between us
and these genii, and the great variety found therein. And
until we find telescopes like those Descartes made us hope
for in order to discern parts of the moon's sphere no larger
than our houses, we cannot determine what there is in a globe
different from ours. Our conjectures will be more useful and
" last and best " ed., with notes and a critical account of the author's writing
by the astronomer Jerome de la Lande, Paris, 1800, by Miss E. Gunning, 1803.
Fontenelle was author also of Dialogues des morts, Paris, 1683; L'Histoire
des Oracles, Paris, 1687 ; Doutes sur le systeme physique des causes occasio-
nelles, against Malebranche, Paris, 1686. — TR.
1 Jacques reads : " fort difficile." — TR.
2 Cf. ante, p. 123, note 2. The book of Kepler here referred to by Leibnitz
is his Sotnniuin seu de astronoinia lunari, Francofurti, 1034, 4to, published
after his death by his son, and found in Frisch, J. Kepleri opera omnia, Vol.
8, Pt. I., pp. 21-39. The concluding paragraphs, pp. 38-39, are of a zoological
and ethnological character. Michaud (Biog. Univ. 22, 313) says it is a philo
sophical and allegorical romance, in which the author exposes the astronomical
phenomena as they would appear to the inhabitants of the moon, who like
ourselves think that they are at the centre of the universe, but who are not so
well situated as we to raise themselves to the " idea " of the true system.
Schaarschmidt states that Kepler had occupied himself with Plutarch's De
facie in orbe lunse (Eng. trans, in Plutarch's Morals, ed. Goodwin, 5, 234-
292 — the Moon-Daemons, 289) and from the tales about the moon-daemons
therein contained related by Sylla, had derived his idea of a lunar geography.
— TR.
3 Franc. Godwin. Cf. ante, p. 342, note 2. — TR.
4 Cf. ante, pp. 228, note 2 ; 399, note 3. The reference is to his Voyage dans
la lune. Cf. The'odicee, Pt. III., § ,'343; Gerhardt, 6, 318; Erdmann, 603 b;
Jacques, 2, 268; Janet, 2, 359, 360; Dutens, 1, 364. — TR.
552 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
more true upon the internal parts of our bodies. I hope that
we shall go beyond conjecture on many occasions, and I already
now believe that at least the violent agitation of the parts of the
tire of which you just spoke should not be reckoned among the
things which are only probable. It is a pity that the hypothesis
of Descartes regarding the constitution (contexture) of the parts
of the visible universe has been so little confirmed by the re
searches and discoveries since made, or that Descartes did not
live fifty years later to give us an hypothesis upon the basis of
present knowledge as ingenious as the one he gave upon the
basis of the knowledge of. his time.1 As for the gradual con
nection of species, we have said something concerning it in a
preceding conference, in which I remarked that philosophers
had already reasoned upon the vacuum in the forms or species.2
Everything goes by degrees in nature, and nothing by leaps, and
this rule regarding changes is a part of my law of continuity.3
But the beauty of nature, which desires distinct perceptions,
demands the appearance of leaps, and so to speak musical ca
dences in phenomena, and takes pleasure in mixing the species.
Thus although there may be in some other world mediate spe
cies between man and beast (according as we understand these
words), and although there may be somewhere rational animals
surpassing us, nature has found it good to keep them away
from us, in order to give us without contradiction the supe
riority we have in our globe. I speak of mediate species, and
I should not wish to regulate myself here by human individ
uals, who approach the brutes, because apparently this is not
a defect of faculty, but a hindrance to its exercise ; so that I
think that the most stupid of men (who is not in a condition
contrary to nature by reason of some disease or some other per
manent defect taking the place of the disease) is incomparably
more rational and more do'/ile than the most spiritual of all
1 Leibnitz here refers to Descartes' theory of vortices, which he elaborated
in his Principia Philosophise, Pts. III. and IV. A brief account of it will be
found in the Encyclop. Brit., J)th ed., article "Descartes," Vol. 7, pp. 107-108
(American Reprint). Of. also J. H. v. Kirchmann's German translation, with
notes, of the Prin. Philos. (Vol. 2(i, Pt. I., of his Philos. Bibliothek.}, 2d ed.
Heidelberg, 1887. For other references of Leibnitz to the theory, cf. Ger-
hardt, Leibniz. philos. Schrift., 4, 283, 288-289, 340 (Dutens, Leibnit. op. om.,
3, 252-253) , 348. — TB.
2 Cf. ante, p. 333-334. — TR.
3 Cf. ante, p. 334, note 1. — TR.
CH. xvi] ON HUMAN UNDERSTANDING 553
the beasts, although the contrary is sometimes said by way of
a witticism. For the rest, I strongly approve the search for
analogies : plants, insects, and the comparative anatomy of
animals will furnish them more and more, especially if we
continue to avail ourselves of the microscope still more than
we have done. And in matters more general you will find
that my views concerning the Monads diffused everywhere,
their unending duration, the conservation of the animal with
the soul, the perceptions undistinguished in a certain condi
tion, such as the death of simple animals, the bodies which
it is rational to attribute to genii, the harmony of souls and
bodies, which causes each to follow perfectly its own laws
without being disturbed by the other and without the necessity
of distinguishing therein the voluntary or the involuntary : you
will find, 1 say, that all these views are entirely conformed to
the analogy of the things which we observe and which I
merely extend beyond our observations, without limiting them
to certain portions of matter or to certain kinds of actions, and
that the only difference therein is from the great to the small,
from the sensible to the insensible.
§ 13. Ph. Yet there is one case where we defer less to the
analogy of natural things which experience has made known
to us, than to the contrary testimony of a strange fact which
is far from it. For when supernatural events are conformed
to the ends of him who has the power to change the course of
nature, we have no reason for refusing to believe them when
well attested, and this is the case of miracles which find not
only belief for themselves, but give it also to other truths
which need such confirmation.1 § 14. Finally, there is a testi-
1 Leibnitz here takes no notice of this remark of Locke concerning miracles,
but expresses himself briefly on the subject in the New Exsayx, Preface, ante,
p. 55, and Bk. IV., chaps. 17 ad fin., infra, p. 582, 19 ad fin., infra, p. 60(5; and
more fully in the Theotlice'e, Discours preliminaire, etc., § 3, Gerhardt, (i, 50,
Erdmann* 480, Jacques, 2, 26, Janet, 2, 34, Dutens, 1, 65, Pt. I., § H4, Pt. II.,
§§ 207, 208, Pt. III., § 241); Dttcoars de metap^yxique, 108(i, §§ 7, 16, G. 4, 432,
441 ; Remarques :ur la lettre de M. Arnaud, May 13, 1(586, G. 2, 40; Letters to
Clarke, G. 7, 352 *q., E. 746 sq., Js. 2, 414 gq., Jt. 2, 617 sq., D. 2, Pt. I., 110 sq.,
trans. Duncan, 238 *g., No. 1, § 4, No. 2, § 12, No. 3, §§ 13-17, No. 4, §§ 33, 40,
42-45, No. 5, §§ 107, 109-113, 115-118 ; Response aux Objections contre le Si/steme
de r/iarmonie pi'e'e'tablie qui se trouvnt dans le Iwre [du P. Francois Lami] de
la Coimoisxance de soy-inewe, 1709, G. 4, 594, E. 4(50, D. 2, Pt. I., 100, and the
Essay, first printed by Gerhardt, 4, 577-590, referring to the same book, and
dated Berlin, Nov. 30/1702, G. 4, 587 ; Letter to Tentzel, 1693, Dutens, 5, 401 j
554 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
mony which outweighs all other assent, viz. revelation, i.e. the
testimony of God, who can neither deceive nor be deceived ;
and the assent we give to it is called faith, which excludes all
doubt as perfectly as the most certain knowledge. But the
point is, to be assured that the revelation is divine, and to
know that we understand its real sense ; otherwise, we are
exposed to fanaticism and the errors of a false interpretation.
And when the existence and the sense of revelation is only
probable, the assent cannot have a greater probability than
that found in the proofs. But we shall speak of this still
farther.
Tli. Theologians distinguish between the motives of credi
bility (as they call them), together with the natural assent
which must spring from them and which cannot have more
probability than these motives, and the supernatural assent,
which is an effect of the divine grace. Books have been
Annotatiunculse subitanese ad Tolandi librum, De Christianismo mysteriis
carente, written Aug. 8, 1701, Dutens, 5, 146, 148; Letters to Hartsoeker, Feb.
6, 1711, G. 3, 517-518, D. 2, Pt. II., 61, Dec. 7, 1711, G. 3, 529; Systema theologi-
ctun, written probably c. 1686, ed. C. Haas, Tubingen, 1860, p. 139. Cf. also
the discussions by Pichler, Theol. d. Leibniz, 1, 226-237 ; K. Fischer, Gesch.
d. n. Philos., Bd. II., Leibniz, 3d ed., pp. 573-576; O. Pfleiderer, Religions-
philosophie, 2d ed., Berlin, 1883, Vol. 1, pp. 90-94, Eng. trans., Vol. 1, pp. 91-93.
Leibnitz — whether consistently or not with his philosophical system is
fairly open to question — certainly admits the possibility, and upon sufficient
and proper evidence the actuality, of miracles in the sense of personal acts of
God in his universe, should a sufficient and proper reason therefor exist in
God's mind. Such acts were not violations of law, but consisted simply in the
substitution of a higher law for a lower, and the introduction of a new force
in accord therewith. Leibnitz justifies his view thus: (1) The laws or order
of nature are not metaphysical necessities, but positive truths, resting on the
divine choice of the best as governed by the divine wisdom, and therefore
amenable to the requirements of that wisdom, the physical always being
subject to the moral order and purpose — " Cum natura rerum nihil aliud sit
quam consuetudo Dei, ordinarie aut extraordinarie agere seque facile ipsi est,
prout sapientia ejus exigit " (Syst. theol. p. 139, ed. Hass, Tub. 1860); (2)
All these acts were foreseen as possible, and as such included in the original
ideal world-plan by the divine intelligence, and therefore involve no change
or inconsistency in that plan; cf. IHscours de inetaphys., § 7, G. 4, 432:
" Or puisque rien ne se pent faire, qui ne soit dans 1'ordre, on pent dire que les
miracles sont aussi bien dans 1'ordre que les operations naturelles, qu'on appelle
ainsi parce qu'elles sont conformes a certaines maximes subalternes que nous
appellons la nature des choses." And he continues in language which would
be quoted more appropriately as a parallel passage to that just cited from
the Syst. theol. : " Car on pent dire que cette nature n'est qu'une coustume de
Dieu, dont il se pent dispenser a cause d'ime raisou plus forte, que celle qui
1'a mu a se s°rvir de ces maximes." — TR.
CH. xvnj UN HUMAN UNDERSTANDING 555
written expressly on the Analysis of Faith which do not alto
gether agree among themselves, but since we shall speak of
this in the sequel, I do not wish to anticipate here what we
shall have to say in its place.
CHAPTER XVII
OF REASON
§ I. Ph. Before speaking distinctly of faith, we shall treat
of reason. It signifies sometimes clear and true principles,
sometimes conclusions deduced from these principles, and some
times the cause, and particularly the final cause. Here we
consider it as a faculty by which man is supposed to be dis
tinguished from the beasts and in which it is evident that he
much surpasses them. § 2. We need it both to extend our
knowledge 1 and to regulate our opinion, and it constitutes,
properly understood, two faculties, sagacity, for the discovery
of mediate ideas, and the faculty of drawing conclusions, or
inference. § 3. We may consider in reason these four degrees :
(1) the discovery of proofs ; (2) their orderly arrangement show
ing their connection; (3) the perception of the connection in
each part of the deduction; (4) the drawing of the conclusion.
We may observe these degrees in mathematical demonstrations.
Th. The reason is the known truth whose connection with
another less known makes us give our assent to the latter. But
in particular and pre-eminently we call it reason, if it is the
cause not only of our judgment, but also of the truth itself,
1 Locke, and in agreement with him here Leibnitz, uses "reason," as
Schaarschmidt says, not in the sense of the vov? of Plato and Aristotle, as the
faculty of ideas and first principles, but in the sense of the Greek A6-yo?, as the
power or faculty of drawing conclusions, thus serving to extend our knowl
edge, a process which may be synthetic and deductive as well as analytic and
inductive. The function of logic in regulating opinion as opposed to its func
tion in extending knowledge is the production of the logical arrangement of
knowledge and the classification of concepts, both of which greatly influence
the reasoning process and its result, and thereby effect both the extension of
knowledge and the regulation of opinion. For a fuller exposition of Locke's
view, cf. J. H. v. Kirchmann, Erlauterimgen zu J. Locke's Versuch ii. d.
mvnschl Verstaml, No. 432, Vol. 52, Pt. II., pp. 105-108, of his Philos.
Bibliothek, Berlin, 1874. — TR.
556 LEIBNITZ'S CRITIQUE OF LOCKE [BK; iv
which we also call reason a priori, and the cause in things corre
sponds to the reason in truths. This is why cause indeed is
often called reason, and particularly final cause. Finally, the
faculty which perceives this connection of truths, or the faculty
of reasoning, is also called reason, and this is the sense you
employ here. Now this faculty is really affected by man alone
here below, and does not appear in other animals here below;
for I have already shown above that the shadow of reason seen
in the beasts is only the expectation of a similar event in a case
apparently similar to the past, without knowing whether the
same reason holds good. Men themselves act no differently in
the cases where they are only empirical. But they raise them
selves above the beasts, in so far as they see the connections of
truths, the connections, I say, which themselves indeed consti
tute the necessary and universal truths. These connections are
indeed necessary although they produce only an opinion, when
after an exact research the prevalence of probability, so far as
may be judged, may be demonstrated, so that then there is
demonstration, not of the truth of the thing, but of the side
prudence requires us to take. In dividing this faculty of
reason, I think we do no wrong in recognizing two parts,
according to a sufficiently received opinion which distinguishes
invention and judgment. As for the four degrees which you
remark in mathematical demonstrations, I find that usually the
first, viz. : the discovery of proofs, does not appear therein, as
is to be desired. There are syntheses, found sometimes with
out analysis, and sometimes the analysis has been suppressed.
Geometers in their demonstrations put first the proposition
which is to be proved, and in order to come to the demonstra
tion they set forth by some figure what is given. This is called
ecthesis. After this they come to the preparation and draw new
lines which they need in the reasoning; and often the greatest
art consists in finding this preparation. This done, they con
struct the reasoning itself, by. drawing inferences from what
was given in the ecthesis and from what has been added thereto
by the preparation; and employing for this purpose truths
already known or demonstrated, they reach the conclusion.
But there are cases where they dispense with the ecthesis and
the preparation.
§ 4. Ph. It is generally believed that the syllogism is the
CH. xvii] ON HUMAN UNDERSTANDING 557
great instrument of reason and the best means of making use
of this faculty. For myself I doubt it, for it serves only to
show the connection of proofs in one single example and no
more; but the mind sees the connection as easily and perhaps
better without it. Those who know how to use the figures and
the moods most frequently take their use for granted by an
implicit faith in their masters without understanding their
reason. If the syllogism is necessary, no one knew anything
whatever by reason before its invention, and it will be neces
sary to say that God having made man a two-legged creature,
left it to Aristotle to make him a rational animal; I mean from
that small number of men that he could induce to examine the
grounds of syllogisms, where among more than sixty ways of
forming the three propositions there are only about fourteen of
them valid. But God has been much kinder to men; he has
given them a mind capable of reasoning. I do not say this to
lower Aristotle, whom I regard as one of the greatest men of
antiquity, whom few have equalled in extent, subtility, pene
tration of mind, and strength of judgment, and who by the very
fact that he has invented this brief system of the forms of
argumentation has rendered a great service to savants against
those who are not ashamed to deny everything. But yet these
forms are not the only nor the best means of reasoning; and
Aristotle did not find them by means of the forms themselves,
but by the original way of the manifest agreement of ideas;
and the knowledge acquired of them in the natural order in
mathematical demonstrations appears better without the aid
of any syllogism. To infer is to draw a proposition as true
from another already advanced as true, by supposing a certain
connection of mediate ideas ; for example, from the proposition
that men will be punished in another world, we infer that they
can determine themselves here. Here is the connection: Men
will be punished and God is the one who punishes; therefore
punishment is just; therefore the punished is guilty ; therefore
he conld have done otherwise; therefore he is free; therefore
finally he has the power of self-determination. The connection
is seen better here than if there were five or six involved
syllogisms, in which the ideas would be transposed, repeated,
and enshrined in artificial forms. The question is to know
what connection a mediate idea has with the extremes in a
558 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
syllogism; but this is ichat no syllogism can show. It is the
mind which can perceive these ideas so placed by a kind of
juxtaposition, and that too by its own view. Of what use
then is the syllogism? It is of use in the schools where men-
are not ashamed to deny the agreement of ideas which plainly
agree. Whence it comes that men never make syllogisms in
their own inquiries after truth or in their teaching of those
who sincerely desire to know it. It is quite plain, also, that
this order is the more natural : —
man — animal — alive ;
i.e. man is an animal, an animal is alive, therefore man is
alive, than that of the syllogism : —
animal — alive, man — animal, man — alive ;
i.e. the animal is alive, man is an animal, therefore man is
alive. It is true that syllogisms may be of use in discovering
a fallacy concealed under the brilliant splendor of an ornament
borrowed from rhetoric, and I had sometimes thought that the
syllogism was necessary, at least to guard against sophisms
disguised under florid discourse; but after a more severe
examination, I have found that we have only to distinguish
the ideas upon which the conclusion depends from those which
are superfluous, and to arrange them in a natural order to show
their incoherence. I knew a man to whom the rules of the
syllogism were wholly unknown, who perceived at once the
weakness and false reasoning of a long artificial and plausible
discourse with which others better skilled in all the finesse of
logic suffered themselves to be entrapped; and I believe that
there will be few of my readers who do not know such persons.
If that were not so, princes in matters relating to their crown
and dignity would not fail to introduce syllogisms into the most
important discussions, where, however, everybody believes it
would be a ridiculous thing to make use of them. In Asia,
Africa, and America, among peoples independent of the Euro
peans, scarcely any one has ever been heard to speak of them.
Finally, it is found after all that these scholastic forms are not
less liable to error; people also are rarely reduced to silence
by this scholastic method and still more rarely convinced and
won. They will recognize at most that their adversary is more
CH. xvn] ON HUMAN UNDERSTANDING 659
adroit, but they do not cease to be persuaded of the justice of
their cause. And if fallacies may be involved in the syllogism,
the fallacy must be discovered by some other means than that
of the syllogism. Yet I am not of the opinion that syllogisms
are to be rejected or that we are to deprive ourselves of any
means capable of aiding the understanding. There are eyes
which need spectacles ; but those who use them should not say
that no one can see well without spectacles. This would be
lowering nature in favor of an art, to which they are perhaps
debtors. Unless it may have happened to them wholly con
trary to the experience of persons who have availed themselves
too much or too soon of spectacles, so that they have so thor
oughly obscured their sight by means of them that they are no
longer able to see without their aid.
Th. Your reasoning on the little use of syllogisms is full of
a number of solid and fine remarks, and it must be admitted
that the scholastic form of syllogisms is little employed in the
world and that it would be too long and perplexing if one
desired to employ it seriously. And yet, would you believe
it, I consider the invention of the form of syllogisms one of
the most beautiful, and also one of the most important, made
by the human mind.1 It is a species of universal mathematics
whose importance is not sufficiently known; and it may be said
that an infallible art is therein contained, provided we know and
can use it. which is not always allowed. Now you must know
that by arguments in form, I mean not merely this scholastic
mode of argument used in colleges, but all reasoning which
concludes by the force of the form, and in which "there is no
need of supplying anything, so that a sorites, another syllogistic
series which avoids repetition, even an account well drawn up,
and algebraic calculation, an infinitesimal analysis, will be for
me almost arguments in form, because their form of reasoning
has been predemonstrated, so that we are certain not to be
deceived thereby. The demonstrations of Euclid most fre
quently come near being arguments in form; for when he
apparently produces enthymemes, the proposition suppressed
and seemingly lacking is supplied by the citation on the mar
gin where is given the means of finding it already demonstrated ;
1 Cf. ante, p. 379, note 2. The letter to G. Wagner is Leibnitz's most com
plete expression of his estimate of the worth of formal logic. — TR.
560 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
this gives a great abstract without taking anything from its
force. These inversions, compositions, and divisions of reasons
which he makes use of are only the species of forms of argu
mentation peculiar and characteristic of the mathematicians
and to the matter they treat; and they demonstrate these forms
with the aid of the universal forms of logic. Further, you must
know that there are good asyllogistic conclusions which also
cannot be rigorously demonstrated by any syllogism without
changing somewhat its terms; and this change itself of terms
makes the conclusion asyllogistic. There are several of these,
as among others, a recto ad obliqnum ; for example, Jesus Christ
is God; therefore the mother of Jesus Christ is the mother of
God. Again, that which clever logicians have called inversion
of relation, as, for example, this conclusion: if David is the
father of Solomon, without doubt Solomon is the son of David.
These conclusions do not cease to be demonstrable by the truths
on which t..e common syllogisms themselves depend. Syllo
gisms also are not merely categorical, but also hypothetical, in
which are comprised the disjunctives. And we may say that
the categorical are simple or complex. The simple categoricals
are those which are usually reckoned, i.e. according to the
moods of the figures; and I have found that the four figures
have each six moods, so that there are twenty-four moods in
all. The four common moods of the first figure are only the
result of the meaning of the signs, All, No, Some. And the
two which I add to them in order to omit nothing are only
the subalterns of the universal propositions. For of these two
ordinary moods, All B is C, and all A is B, therefore all A is
C; again. No B is C, All A is B, then no A is C, we make these
two additional moods, All B is C, All A is B, then some A is C;
again, No B is C, All A is B, then some A is not C. For it is
not necessary to demonstrate the subaltern and to prove its
conclusions : All A is C, then some A is C ; again, No A is C,
then some A is not'C, although we may, however, demonstrate
it by the identicals joined with the moods already received of
the first figure, in this way: All A is C, Some A is A, then
some A is C; again, No A is C, Some A is A, then some A is
not C. So that the two additional moods of the first figure are
demonstrated by the first two ordinary moods of the said figure
with the intervention of the subaltern, itself demonstrable by
CH. xvn] ON HUMAN UNDERSTANDING 561
the other two moods of the same figure.1 In the same way the
second figure receives also two new ones. Thus the first and the
second have six; the third has had six always; the fourth was
given five, but it is found to have six also by the same principle
of addition. But we must know that logical form does not
bind us to this order of propositions which we commonly use,
and I am of your opinion, sir, that this other arrangement is
superior in value: All A is B, All B is C, therefore all A is C,
which would be particularly by the sorites, which are a chain
of such syllogisms. For if there were one more of them: All
A is C, All C is D, therefore all A is D, we may make a chain
of these two syllogisms, which avoids the repetition by saying:
All A is B, All B is C, All C is D, therefore all A is D, wherein
we see that the useless proposition All A is C is neglected, and
the useless repetition of this same proposition which the two
syllogisms would demand is avoided; for this proposition is
henceforth useless, and the chain is an argument perfect and
in good form without this same proposition when the force of
the chain of reasoning has once for all been demonstrated by
means of these two syllogisms. There is an infinite number
of other chains of reasoning more complex, not only because
a greater number of simple syllogisms enter therein, but also
because the ingredient syllogisms exhibit greater differences
among themselves, for there may be made to enter into them
not only simple categoricals, but also copulatives, and not
only categoricals, but also hypotheticals; and not only com
plete syllogisms, but also enthymemes, wherein the propo
sitions believed evident are suppressed. And all this joined
with the asyllogistic conclusions, and with the transposi
tions of the propositions, and with a multitude of turns and
thoughts which conceal these propositions through the natural
inclination of the mind to abridge, and by the properties of
language appearing in part in the employment of the parti
cles, will make a chain, of reasoning which will represent
the entire argumentation indeed of an orator, but emaciated
1 Cf. Di fficultates qusedam lor/icie, Gerhardt, 7, 211-217, Erdmann, 101-104;
also Leibnitz's letter to Bourguet, March 22, 1714, G. 3, :>(>5)-70, E. 723 b.
The youthful demonstration referred to in this letter is found in the Dis-
sertatio de Arte Combinatoria, 1(>6(>, Problem II., § VI., G. 4, 4<i sq., E. 13 b.
sq., Dutens, 2, Pt. I., 352 sq., and is Leibnitz's most thorough and elaborate
treatment of the moods and figures of the syllogism. — TR.
2 o
562 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
and stripped of its ornaments and reduced to logical form, not
scholastically, but always sufficiently to recognize its force,
according to the laws of logic, which are none else than those
of good sense, placed in order and in writing, and which differ
no more than the custom of a province differs from what it had
been when from unwritten as it was, it has become written,
except that being put in writing and being capable of being
better seen at once, it furnishes more light to enable it to be
pushed and applied; for natural good sense without the aid of
art, making the analysis of certain reasoning, will sometimes
be a little in trouble regarding the force of conclusions, finding
some, for example, which include some mood, valid for truth
but less ordinarily used. But a logician who wished us not to
make use of such series, or wished not to make use of them
himself, claiming that we must always reduce all the complex
arguments to the simple syllogisms on which in fact they de
pend, would be, according to what I have already said to you,
like a man who wished to compel the merchants of whom lie
buys something to count for him the numbers one by one, as we
count on the fingers, or as we count the hours of the town-clock ;
a procedure which would indicate his stupidity, if he could not
count otherwise, or if he could discover only at his fingers'
ends that five and three make eight, or rather it would indicate
a caprice if he knew these short methods and did not wish to use
them or to allow us to use them. He would be also like a man
who wished us not to employ axioms and theorems already
demonstrated, claiming that we must always reduce all reason
ing to first principles in which is seen the immediate connection
of the ideas upon which in reality these mediate theorems
depend.
After having explained the use of the forms of logic in the
way in which I think it should be understood, I come to your
considerations; and I do not see, as you wish, sir, that the
syllogism serves merely to exhibit the connection of proofs in a
single example. To say that the mind always sees easily the
conclusions, is a statement which will not be found true ; for
we sometimes see some (at least in the reasonings of another)
where there is room for doubt at first so long as their demon
stration is not seen. Ordinarily, we use examples to justify
conclusions, but this method is not always sufficiently sure.
CH. xvn] ON HUMAN UNDERSTANDING 563
although there is an art of choosing examples which would not
be found true if the conclusions were not valid. I do not
believe it would be permitted in well-governed schools to deny
without any shame the manifest agreement of ideas, and it does
not appear to me that we employ the syllogism to show them.
At least this is not its unique and principal use. You will find
oftener than you think (in examining the paralogisms of
authors) that they have sinned against the rules of logic, and
I have myself found by experience sometimes in discussion,
even by writing, with persons of good faith, that we began to
be understood only when we argued in form in order to disen
tangle a chaos of reasonings. It would without doubt be ridic
ulous to wish to argue after the scholastic fashion in important
deliberations, because of the importunate and embarrassing
prolixities of this form of reasoning, and because it is like
counting on the fingers. But yet it is only too true that in the
most important deliberations regarding life, tne state, salva
tion, men allow themselves to be dazzled often by the weight
of authority, by the gleam of eloquence, by examples badly
applied, by enthymemes falsely supposing the evidence of that
which they suppress, and even by faulty conclusions ; so that a
severe logic, but of another turn than that of the School, would
be only too necessary for them, among other things, to deter
mine upon which side is the greatest probability. For the
rest, the fact that the common herd of men ignore artificial
logic, and that they do not cease thereby to reason well and
sometimes better than the class practised in logic, this fact
proves not its inutility any more than it would prove the
inutility of artificial arithmetic, because we see that some per
sons count well on ordinary occasions without having learned
to read or write and without knowing how to handle the pen or
the tokens as far as to rectify the errors of another who has
learned to calculate, but who may be neglectful or confused in
the characters and signs. It is true that syllogisms also may
become sophistical, but their own laws serve to recognize them;
and syllogisms do not convert or indeed conquer always-; but
this is because the abuse of distinctions and of badly understood
terms renders their use prolix until it becomes insupportable,
if it must be driven to extremities.
It remains for me here only to consider and to supplement
564 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
your argument, employed as an example of clear reasoning
without the form of the logicians: God punishes man (an
assumed fact) ; God punishes justly the one he punishes (a truth
of reason which may be regarded as demonstrated) ; therefore
God punishes man justly (a syllogistic conclusion extended
asyllogistically a recto ad obliquum) ; therefore man is justly
punished (an inversion of relation, but which is set aside
because of its evidence) ; therefore man is guilty (an enthymeme,
in which is suppressed this proposition which in reality is only
a definition : he who is punished justly is guilty) ; therefore man
could have done differently (a suppression of this proposition :
he who is guilty could have done differently); therefore man
was free (a further suppression: he who could have done differ
ently was free); therefore (by the definition of freedom) he had
the power of self-determination; which was to be proved. Re
garding which I remark further that this therefore itself
includes in reality both the unexpressed proposition (that he
who is free has the power of self-determination) and is useful
in avoiding the repetition of terms. And in this sense noth
ing would be omitted, and the argument in this view might pass
as complete. You see that this reasoning is a series of syllo
gisms entirely in accord with logic ; for I do not now wish to
consider the matter of this reasoning, wherein there might per
haps be some remarks to make or some explanations to demand.
For example, when a man cannot do differently, there are some
cases in which he might be guilty before God, as if he were
very glad to be unable to aid his neighbor in order to have an
excuse. To conclude, I admit that the scholastic form of
arguing is ordinarily inconvenient, insufficient, badly managed,
but I say at the same time that nothing would be more impor
tant than the art of arguing in form according to true logic,
i.e. fully as to matter and clearly as to the order and force of
the conclusions, whether self-evident or predemonstrated.
§ 5. Ph. I thought that the syllogism would be still less
useful, or rather of absolutely no use in probabilities, because
it pushes only a single topical argument.1 But I see now that
1 Aristotle, Topics, I., 1, 100a 27 sq., designates the "topical argument" as
6 SiaAeKTiKb? <rvAAoyi(Tjuios, Or 6 e£ ev86£uv <rv\\oyi£6nei>os, i.e. the dialectic SyllO-
gism, or the syllogism which reasons from the probable in distinction from
i7r6Sei£ts, or the proof resting upon and leading back to first and necessaiy
CH. xvn] ON HUMAN UNDERSTANDING 565
it must always furnish solid proof of what is certain in the
topical argument itself, i.e. the probability therein found, and
that the force of the conclusion consists in the form. § 6. But
if syllogisms serve only in judging, I doubt whether they are
capable of use in invention, i.e. in finding proofs and making
new discoveries. For example, I do not think that the dis
covery of the 47th proposition of the first book of Euclid is due
to the rules of ordinary logic, for we first know it and then are
able to prove it in syllogistic form.
Th. Comprising under syllogisms also the series of syllo
gisms and everything which I call formal argumentation, we
may say that knowledge, not self-evident, is acquired by infer
ences which are valid only when they have their due form. In
the demonstration of the said proposition which makes the
square of the hypothenuse equal to the squares of the two
sides, we divide the large square into parts and likewise the
two small ones, and we find that the parts of the two small
squares may all be found in the large one and neither more nor
less. This is the proof of equality in form, and the equality
of the parts is also proved by arguments in valid form. The
analysis of the ancients was, according to Pappus, to take what
is asked and to draw therefrom conclusions until they come to
something given or known. I have remarked that for this
result the proposition must be reciprocal in order that the
synthetic demonstration may return in the contrary direction
by the paths of analysis, but it is always a drawing of conclu
sions. It is well, however, to remark here that in astronomical
or physical hypotheses the return does not take place; but in
like manner success does not demonstrate the truth of the
hypothesis. It is true it renders it probable, but as this proba
bility appears to violate the rule of logic which teaches that
the true may be drawn from the false, it will be said that
logical rules will not have entire sway in probable questions.
I reply that it is possible for the true to be concluded from the
truths. Cf. also Topics, VIII., 11, 102a 15, where he calls the o-vAAoyia-wbs
fiiaAe/cTiKOS an en-ixetpi?/oia Or attempted proof, and the o-vAAovicr^o? a7ro6ei/cTt»c6? a
</>iAoo-64>T}/xa or demonstration. On the whole subject, cf. Zeller, Pliilos. d.
Griech., II., 2 [Vol. 4], 242 sq., 3d ed., 1879; Prantl, Gesch. d. Loc/ik, 1, 95 sq.;
Wallace, Outlines of the Philos. of Aristotle, § 23, pp. 47-48. Cf. also, New
Essays, Bk. II., chap. 21, § <>6, Th. (2), ante, p. 214, note 1; Bk. IV., chap. 2,
§ 14, Th., ante, p. 418, note 4. — TR%
566 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
false, but it is not always probable, especially when a simple
hypothesis gives a reason for many truths, a thing which is
rare and difficult to find. We might say with Cardan,1 that the
logic of the probable has other consequences than the logic of
the necessary truths. But the probability itself of these con
clusions must be demonstrated by the conclusions of the logic
of the necessary truths.
§ 7. Ph. You appear to apologize for common logic, but I
see clearly that what you bring forward belongs to a more
sublime logic, to which the common is only what the alphabet
is to scholarship : a fact which makes me remember a passage
of the judicious Hooker, who in his book entitled " Ecclesiasti
cal Polity," Book I., § 6, thinks that if we could furnish the true
helps of knoidedge and of the art of reasoning, which in this age
passing as enlightened are not much known and for which
people put themselves to very little trouble, there would be as
much difference as regards maturity of judgment between men
who would make use of them and what men now are, as between
the men of the present and imbeciles.'2 I wish that our con
ference may give occasion to some to make a discovery of these
true helps of the art of which this great man who had so pene
trating a mind speaks. They \vill not be the imitators who like
the cattle follow the beaten track (imitatorum servum pecus).3
1 Girolamo Cardano, 1501-1576, an Italian physician, mathematician, and
philosopher, whose complete works appeared at Lyons, 1663, 10 vols., fol., and
an account of whose philosophy will he found in Stockl, Gesch. d. Philos. d.
Mittelalters, III. [Vol. 4], 45l>-458. — TR.
2 Richard Hooker, 1553-1600, attempted, in his Laics of Ecclesiastical
Polity, to defend the Episcopal form of government of the Church of Eng
land, as established by the Protestant sovereign and Parliaments, against the
attacks of the Presbyterians. To this end he gives in the two first books of
his work an exposition of the fundamental principles by which the disputed
question should be decided, especially of the nature of law in general, as a
philosophical basis for the rest of his discussion. It is this portion of his
work that gives it its permanent place and value in English literature and
philosophy.
The passage here referred to by Locke and Leibnitz runs thus, Eccles.
Pol., Bk. I., chap. 6, § 3, Work*, ed. Isaac Walton, Oxford, Univ. Press, 1841,
2 vols., 8vo, Vol. 1, p. 164 : " Wherefore if afterwards there might be added
the right helps of true art and learning (which helps, I must plainly confess,
this age of the world, carrying the name of a learned age, doth neither much
know nor greatly regard) , there would iindoubtedly be almost as great dif
ference in maturity of judgment between men therewith inured, and that
which men now are, as between men that are now and innocents." — TR.
3 Cf. Horace, Epist., 1, 19, 19. —TR.
CH. xvn] ON HUMAN UNDERSTANDING 567
Yet I dare say there are in this age some persons of such
strength of judgment and of such large extent of mind, that
they could discover new paths for the advance of knowledge,
if they would take the trouble to turn their thoughts in that
direction.
Th. You have well remarked, sir, with the late Mr. Hooker,
that the world troubles itself but little about this; otherwise
i think there are and have been persons capable of succeed
ing therein. We must admit, however, that now we have
great helps both on the side of mathematics and of philoso
phy, in which the Essay concerning Human Understanding
of your excellent friend is not the least. We shall see if
we may not be able to profit therefrom.
§ 8. Ph. I must further tell you, sir, that I have believed that
there was a visible mistake in the rules of the syllogism ; but
since we have conferred together you have made me hesitate.
I will, however, set before you my difficulty. It is stated that
no syllogistic reasoning can be conclusive unless it contains at least
one universal proposition.1 But it seems that there are in the
syllogism only particular things, which are the immediate
object of our reasonings and knowledge; they revolve only
about the agreement or disagreement of ideas, each of which
has only a particular existence and represents only an individ
ual thing.
Th. As far as you conceive the similarity of things you con
ceive something more, and the universality consists only in
that. Yet you will never propose to me any one of our argu
ments without therein employing the universal truths. It is,
however, well to remark that (as far as form is concerned) the
particular propositions are comprised within the universals.
For although it is true that there is only a single St. Peter the
1 Locke's sensistic realism appears in sharp outlines in the present passage
and its immediate context; cf. further, Locke, Philos. Whs., Vol. 2, pp. 29")-
2!>6. He maintains the existence, and consequently the knowledge, of the par
ticular and individual only, and that our reasoning, which relates to the
agreement or disagreement of things, must accordingly, in order to hit the
mark, confine itself to the particular. Leibnitz argues, on the other hand,
that our knowledge of things, while beginning with the particular in the
sense-act, does not rest there, but through thought, especially through the
medium of the linguistic form of our mental creation, gives to the individual
and particular at once the character of universality. With Locke the ele
ment of universality is accidental ; with Leibnitz it is essential. — TR.
568 LEIBNITZ'S CRITIQUE OF LOCKE [HK. iv
apostle, we may nevertheless say that whoever was St. Peter
the apostle denied his master. Thus this syllogism: St. Peter
denied his master, St. Peter was a disciple, therefore some
disciple denied his master (although it has only particular
propositions), is considered to have them as universal affirma
tives, and the mood will be Darapti of the third figure.1
Ph. I wished also to say to you that it appeared to me better
to transpose the premises of the syllogisms and to say: All A
is B, All B is C, therefore All A is C, than to say : All B is C,
All A is B, therefore All A is C. But it seems from what you
have said that they do not differ, and that both are counted as
one and the same mood. It is always true, as you have
remarked, that the disposition different from the common is
better adapted to making a chain of several syllogisms.
Th. I am wholly of your opinion. It seems, however, that
the belief has been that it was more didactic to begin with
universal propositions like the majors in the first and second
figures; and there are indeed orators who have this custom.
But the connection appears better as you propose. I have
before remarked that Aristotle may have had a particular
reason for the common disposition. For instead of saying A
is B, he was wont to say B is in A. And with this method of
statement, the connection itself which you demand will arise
for him in the received disposition. For, instead of saying B
is C, A is B, therefore A is C, he will state it thus : C is in B,
B is in A, therefore C is in A. For example, instead of saying:
The rectangle is isogon (or has equal angles), the square is a
rectangle, therefore the square is isogon, Aristotle, without trans
posing the propositions, will preserve the middle place to the
middle term by this method of stating the propositions, which
reverses the terms, and will say: The isogon is in the rectangle,
the rectangle is in the square, therefore the isogon is in. the square.
And this mode of statement is not to be despised, for in reality
1 Peter being the middle term, and disciple the subject of the conclusion,
the minor premise must be converted, by which process the universal affirma
tive, "St. Peter was a disciple," becomes the particular affirmative, "Some
disciple was St. Peter," from which the particular conclusion, " Some disciple
denied his master," immediately follows. The mood Darapti of the third
figure thus becomes the mood Darii of the first. The universality of the
premises consists in the fact that Peter constitutes the entire class to which
he belongs. Cf. Hamilton, Logic, Boston, 1873, pp. 314-315. — TR.
CH. xvn] ON HUMAN UNDERSTANDING 569
the predicate is in the subject, or rather the idea of the predi
cate is included in the idea of the subject. For example, the
isogon is in the rectangle, for the rectangle is the figure all of
whose right angles are equal to each other, therefore in the
idea of the rectangle is the idea of a figure all of whose angles
are equals, which is the idea of the isogon. The common mode
of statement regards rather individuals, but that of Aristotle
ideas or universals. For in saying, every man is on animal, I
mean to say that all men are included in all animals; but I
mean at the same time that the idea of animal is included in
the idea of man. Animal includes more individuals than man,
but man includes more ideas or more formalities; ] the one has
more examples, the other more degrees of reality; the one more
extension, the other more intension. It may also be truly said
that the entire syllogistic doctrine may be demonstrated by
that de continents et contento, the containing and the contained,
which is different from that of the whole and the part; for the
whole always exceeds the part, but the containing and the
contained are sometimes equal, as is the case in reciprocal
propositions.2
§ 9. Ph. I begin to form for myself a wholly different idea
of logic from that I former!}' had. I regarded it as a scholar's
diversion, but I now see that, in the way you understand it, it
is like a universal mathematics. Would to God that it might
push on to something more than it yet is, in order that we
1 I.e. essences. " The formality of the vow lies in the promise made to
God." — Stillingrleet. — Tu.
2 Leibnitz's thought, as Schaarsehmidt says, is that sometimes the princi
ple, what is predicable of the whole is predicable of the parts — ab universali
ad particular? consequent/a valet — is not applicable, as in cases where the
concepts found in the conclusion are coordinate rather than subordinate,
i.e. coincident or identical in extension. In such cases the coordination or
coincidence of the concepts — principium identitatis — might be adduced as a
fundamental logical principle. To avoid this, Leibnitz proposes the principle
DP, continent? et contento, in which in a certain sense is given the higher
unity of subordination and identity, i.e. the subject may always be thought
of as contained in the predicate, although coincident with it in extension.
The principle, however, necessarily considers "the containing" as more ex
tended than the " contained." Cases such as Leibnitz here refers to, in which
the coordination or agreement of terms is such as to make them identical —
"important cases" "for 'the most part strangely overlooked" by logicians
(Jevons, Lessons in Logic, p. 124, new ed., 1880) — are discussed by Jevons in
his little work entitled The Substitution of Similars, London, Macmillan & Co.,
18!J9. — TR.
570 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
might be able to find thereby these true helps of reason of which
Hooker spoke, which would raise men far above their present
condition. Reason is a faculty which so much the more needs it,
as its extent is quite limited and as it fails us in many instances.
(1) Because often ideas themselves fail us. § 10. Then (2) they
are often obscure and imperfect; whilst where they are clear
(and distinct), as in numbers, we find no insurmountable diffi
culties, and fall into no contradiction. § 11. (3) Often also
the difficulty comes from the fa?t that mediate ideas are want
ing. You know that before algebra, that great instrument and
noteworthy proof of human sagacity, was discovered, men
regarded with amazement many demonstrations of the ancient
mathematicians. § 12. It also happens (4) that the mind builds
upon false principles, which may entangle it in difficulties
where the reason is more involved and very far from clearing
them up. § 13. Finally (5), terms whose meaning is uncertain
embarrass the reason.
Th. I do not know whether we so much lack ideas as you
think, that is to say, distinct ideas. As for confused ideas., or
rather images, or, if you prefer, impressions, as colors, tastes,
etc., which are a resultant of many little ideas distinct in
themselves, but of which we are not distinctly conscious, we
lack an infinite number of them suitable to other creatures
rather than to ourselves. But these impressions also serve
rather to give rise to the instincts and to establish the observa
tions of experience than to furnish matter to the reason, except
so far as they are accompanied by distinct perceptions. It is
then principally the defect of the knowledge we have of these
distinct ideas, concealed within the confused, that stops us,
and even when all is distinctly exposed to our senses or to our
mind, the multitude of things that must be considered some
times perplexes us. For example, when there is a pile of one
thousand cannon-balls before our eyes, it is plain that in order
properly to conceive the number and properties of this multi
tude, it is very useful to arrange them in figures as is done in
the magazines in order to have distinct ideas of them and to
fix them, indeed, so that we may be spared the trouble of
counting them more than once. It is the multitude of consid
erations also which causes some very great difficulties in the
science of numbers themselves; for short methods are sought
CH. xvn] ON HUMAN UNDERSTANDING 571
and sometimes we do not know whether nature has them within
its folds for the case in question. For example, what is
apparently simpler than the notion of the prime number? i.e. a
whole number indivisible by every other except unity and
itself. Yet we seek also a positive and easy sign in order to
recognize them certainly without trying all the prime divisors
less than the square root of the given prime. There are a
number of signs which make known without much calculation
that a given number is not prime, but we ask for one which is
easy and which makes known certainly that it is prime when
it is so. This it is which also makes algebra as yet so imper
fect, although nothing is better known than the ideas of which
it makes use, since they signify only numbers in general; for the
public has not yet the means of extracting the irrational roots
of any equation beyond the fourth degree l (excepting in a very
limited case), and the methods which Diophant,2 Scipio Ferreus,3
1 In Leibnitz's day, as the text states, equations of the 2d, 3d, and 4th
degrees were reduced to pure equations, but the reduction of equations of
higher degrees than the 4th remained an unsolved problem, on which mathe
maticians spent much labor, until Niels Henrik Abel, 1802-1829, a Norwegian
mathematician of great ability and acuteness, demonstrated (1824) that the
quint ic equation and a fortiori the general equation of any order higher than
five, is incapable of solution by radicals. Cf. Abel, Demonstration de Vim-
possibilite de la resolution algebrique des equations generates qui passent le
qaatrieuie deyre, in CEuvres completes, ed. by Holmboe, 2 vols., Christiania,
1839, Vol. 1, pp. 5-24, and in Crelle, "Jo urn. f. Math.," 1820, Vol. 1, pp.
65-84.— TR.
2 Diophant'us, c. 325-c. 409, a celebrated Greek mathematician of the
Alexandrian school, gave, in his Arithmeticorum lib. VI., a method for the
solution of equations of the 1st and 2d degrees. The Ms. of his Arithmetic
was discovered in 1460 in the Vatican Library by the astronomer Regiomon-
tanus, 143(5-1470, and was published in a Latin trans., without the original, by
Xylander, in 1575. The Greek text, with a more complete trans., and a com
mentary by Bachet de Merzeriac, whose skill in indeterminate analysis
especially fitted him for the task, appeared in 1621. The best ed., based upon
that of Bachet, including the Greek text with Latin trans., is that by Pierre
Fermat, 1001-1005, the celebrated French mathematician, who supplemented
the commentary of Bachet by valuable notes of his own. It is found in Vol.
1, pp. 05-341 of Fermat, Opera Mathematica, 2 vols., fol., Tolosse, 1070, 1679.
- TR.
3 Scipione del Ferro or Ferri, c. 1405-1525, an Italian mathematician, taught
arithmetic and geometry at Bologna from 149(5 till his death. About 1505 he
discovered the solution of a particular case of cubic equations, which he did
not publish, but communicated to his favorite pupil Antonio del Fiore, who in
1(535 challenged Tartaglia to a trial of skill in resolving algebraical problems
requiring a knowledge of this rule. Tartaglia in 1(530 had already solved two
cases of cubic equations, and before the time for the contest came solved two
572 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
and Lewis Ferrari l used respectively for the second, third,
and fourth degrees in order to reduce them to the first, or
in order to reduce an affected equation to a pure, are wholly
different from each other, i.e. that which is used for one degree
differs a degree from that used for another. For the second
degree, or the quadratic equation, is reduced to the first by
merely eliminating the second term. The third degree, or the
cubic equation, has been solved, because in separating the
unknown quantity into parts there happily arises from these
an equation of the second degree. And in the fourth degree,
or the biquadratics, something is added to the two sides of the
equation to render it capable of extraction on both sides, and
then it is happily found that to obtain this result an equation
of the third degree only is needed. But all this is only a mix
ture of good luck or chance with art or method. And in trying
it on these last two degrees we knew not whether it would be
successful. Further still, another artifice is necessary to suc
cess in the fifth or sixth degree, which are the sursolids or
bicubes. And although Descartes believed that the method he
used in the fourth, conceiving the equation as produced by two
other quadratic equations (but which cannot at bottom give
more than, that of Lewis Ferrari), would succeed also in the
sixth, it is not found to be so. This difficulty shows that even
the clearest and most distinct ideas do not always give us all
we ask for and all that may be drawn from them. And this
makes us also judge that algebra is very far from being the art
more. He thus easily won the victory, as his problems could be solved only
by one or the other of his own three rules which were unknown to Fiore. and
not by the remaining rule which was the only one known to Fiore. Tartaglia's
discoveries were improved and published by Cardan in connection with his
own in lf>-}5, as a supplement to a treatise on arithmetic and algebra pub
lished in 15:!9. Cf. Cardan, Opera omnia, Vol. 4, pp. 249-2C4. On Ferro, cf.
Libri, Hist, dcs Sciences Math, en Italic, Vol. 3, pp. 14S-151 ; Montucla, Hist.
<les Mat?)., Vol. 1, p. 479, ed. 1758, Vol. 1, p. 591, ed. 1799-1S02. — TR.
1 Ludovk'O or Luigi Ferrari, 1522-1 5P>2, or 15(i5. an Italian mathematician, a
pupil of Cardano (cf. ante, p. 5(i(>, note 1), and Professor of Mathematics at Milan
and at the University of Bologna, discovered the demonstration of the formula
for the resolution of equations of the 3d degree, sent by Tartaglia, c. 1500-1557,
to Cardan under the form of an enigma, and shortly after this discovery solved
equations of the 4th degree. For an account of his demonstration, cf. Cardan,
Ars rnagna, 1545, chap. 15. De cubo et quadratis a^qualibus numero, § 3,
Opera onmia, 10 vols., Lugduni, IGtiS, Vol. 4, p. 254. On Ferrari, cf. Libri,
Hist, dcs Sciences Math, en Italic, Vol. 3, pp. 180, 181; Montucla, Hist, des
Math., Vol. 1, pp. 484, 485, ed. 1758, Vol. 1, pp. 59(5, 597, ed. 1799-1802. — Tu.
CH. xvnj ON HUMAN UNDERSTANDING 573
of invention, since it needs a more general art; and we may
say, indeed, that the art of signs (Specieuse) in general, i.e. the
art of characters, is a marvellous means of assistance, since it
aids the imagination. It will not be doubted in view of the
arithmetic of Diophant and the geometrical books of Apollonius
and Pappus that the ancients possessed it to a certain extent.
Vieta1 has given it more extension by expressing not only what
is asked for, but also the given numbers, by general characters,
doing in calculating what Euclid already did in reasoning, and
Descartes has extended the application of this calculus to
geometry, indicating lines by equations. Nevertheless, even
after the discovery of our modern algebra, Bouillaud 2 ([smael
Bullialdus), no doubt an excellent geometer, whom, moreover,
I knew in Paris, regarded only with wonder the demonstrations
of Archimedes upon the spiral, and could not understand how
this great man had thought of employing the tangent of this
line as the dimension of the circle. Father Gregory of St.
Vincent3 appears to have divined it, thinking that it was at
tained by the parallelism of the spiral and the parabola. But
this method is only a particular one, whilst the HCAV calculus
of infinitesimals4 which proceeds by the method of the differ
ences which I have thought of and successfully shared with the
public, gives a general one, wherein this discovery concerning
1 Cf. ante, p. 408, note 1. — TR.
2 Ismael Boulliau, 1<;05-16:>4, a French mathematician and astronomer, who
was the first to give, in his Ad astrvmnnos tnotnta duo, 1057, a plausible ex
planation of the change in the light of some stars by attributing to them an
axial revolution which shows successively their obscure and luminous parts.
He was the author of several works, among which is the De lineis spirali.jus
denioiiNtraHoncs, 10.57, which Leibnitz, perhaps, had in mind here. — TR.
3 Gregoire de Saint-Vincent, 1584-1007, a Flemish geometer who was much
occupied with the problem of the quadrature of the circle, and whose prin
cipal work is the Opus yeuiuetricum quadrature circuit et sictionain con/,
1047. — TR.
4 For Leibnitz's account of his discovery of the " calculus of infinitesimals,"
c-f. his Historia ct orif/o calculi difl'erentialis, Gerhardt, Leibniz, mat//. 8chr(ft.t
II., 1 [Vol. 5], 392-410; also his letter, April 18, 1710, to the Countess Kiel-
mannsegge, Dutens, L^-ibiiit. op. out., 3, 450-401. For Leibnitz's various writ
ings on the subject, cf. Gerhardt, op. cit., II., 1 [Vol. 5], 141-418: Dutens, ojp. cit.,
Vol. 3, passim. Dutens, Vol. 3, contains also much material concerning the
controversy between Leibnitz and Newton regarding the discovery of the
calculus. Further accounts are given in Guhrauer, Leibnitz, Einc. Jtiof/raphie,
1, 280-320, Jaucourt, Historia vitse Leibnitii, and Montucla, Hist. d. Math.,
Vol. 2 (both in Dutens, op. cit. Vol. 3, pp. xii-xl, xli-lv), and in Encyclop.
Brit., 9th ed., Vol. 13, Article, " Infinitesimal Calculus." — TR.
574 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
the spiral is mere play and a sample of the easiest, like nearly
all we have before discovered in the matter of the dimensions
of curves. The reason of the advantage of this new calculus
is, moreover, that it relieves the imagination in the problems,
which Descartes excluded from his geometry under the pre
text that they most frequently lead to mechanics, but at
bottom because they did not agree with his calculus. As
for errors arising from ambiguous terms, it is our business
to avoid them.
Ph. There is also a case in which reasoning cannot be
applied, but in which also there is no need of it and in which
sight is worth more than reasoning. It is in intuitive knoid-
edge, where the connection of ideas and truths is immediately
seen. Such is the knowledge of indubitable maxims, and I am
tempted to believe that this is the degree of evidence which
the angels have at present, and which the spirits of just men
made perfect will have in a future state regarding a thousand
things which now escape our knowledge. § 15. But demon
stration, based upon mediate ideas, gives a reasoned knowledge.
This is because the connection of the mediate idea with the
extremes is necessary and is seen by ^juxtaposition of evidence,
similar to that of a yard-stick applied now to one cloth and now
to another to show that they are equal. § 16. But if the con
nection is only probable, the judgment gives only an opinion.
Tli. God alone has the advantage of having only intuitive
knowledge. But very happy souls, however detached they are
from these material bodies, and the genii themselves, however
exalted they are, although they have a knowledge without com
parison more intuitive than ours, and often see at a glance what
we discover only by the force of consequences after having em
ployed time and labor, must likewise find difficulties in their path
without which they would not have the pleasure of making dis
coveries, which pleasure is one of the greatest. And we must
always admit that there will be an infinite number of truths
concealed from them either wholly or for a time, whereto they
must attain by force of consequences and by demonstration or
even frequently by conjecture.
Ph. [These genii then are only animals more perfect than
we ; it is just as if you said with the emperor of the moon : it
is all as here."]
CH. xvn] ON HUMAN UNDERSTANDING 575
Tli. I will say so, not entirely, but in regard to the ground of
things, for the modes and degrees of perfection vary infinitely.
Meanwhile the ground is everywhere the same, a maxim which
is fundamental with me and reigns in all my philosophy. I con
ceive things unknown or confusedly known only after the manner
of those which are distinctly known to us ; a procedure which
makes philosophy very easy, and I believe indeed that it must
do so. But if this philosophy is simplest in its ground, it is
also the richest in its modes, because nature may vary them
infinitely, as indeed she has done with as much abundance,
order, and ornateness as it is possible to imagine. This is the
reason why I believe there is no genius however sublime who
has not an infinite number of them above him. Yet although
we are very inferior to so many intelligent beings, we have the
advantage of not being visibly controlled upon this globe where
we hold indisputably the tirst rank ; and with all the ignorance
in which we are immersed we have always the pleasure of seeing
nothing which surpasses us. And if we were vain we might
judge as Csesar, who preferred to be first in a country town
rather than second in Koine. For the rest, I speak here only
of the natural knowledge of these spirits and not of the beatific
vision,1 or of the supernatural light that God is pleased to give
them.
1 The term "beatific vision" (visio beatiftca) denotes in theological and
religious thought the direct and immediate or intuitive vision of God enjoyed
by the saints and angels in heaven and supposed to constitute their essential
bliss. The philosophical significance of the idea as historically developed,
with respect both to its speculative and practical uses, lies in the fact that the
visio beatijica was regarded as the sole means of obtaining absolute truth and
of realizing absolute blessedness. The idea thus involved more or less ex
plicitly a species of knowledge supernaturally mediated in some unknown and
unexplained way, but considered, because of the method of its mediation, as
far superior in certainty and completeness to any knowledge that finite beings
could attain through the unaided action of their own intellectual powers —
in brief, as the very perfection of knowledge attainable by such beings.
The idea originated in Plato's conception of an immediate intuition, going
beyond rational thought, of the pure forms of reality or the Ideas. Trans
formed by Philo and Plotinus into their ecstatic intuition, or that identifica
tion of the human with the Divine in which all consciousness of individual
personality is lost ; combined by Clement and Origen, in view of certain ex
pressions in the Pauline epistles, with the thought of a personality in union
with whom the self-consciousness of the individual is preserved ; and still
further developed by Augustine, as the principle of the absolute and imme
diate certainty of inner experience or consciousness involving within itself
the idea of God as the absolute personality and the sum and essence of all
570 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
§ 19. Ph. As each one makes use of reasoning either with
regard to himself or with reference to another, it will not be
useless to make some reflections upon four sorts of arguments
which men are wont to use in order to draw others to their
opinions or at least so to keep them in awe as to prevent them
from contradicting. The first argument may be called argu
mentum ad vercundiam, when we cite the opinion of those
who have acquired authority by their knowledge, rank, power,
or otherwise ; for when another does not yield to it promptly,
he is liable to be censured as full of vanity and even to be
charged with insolence. § 20. There is also 2) argumentum
ad ignomntiam, i. e. to demand that the opponent admit the
proof or assign a better. § 21. There is o) argumentum ad
liominem, when we press a man by what he has himself said.
§ 22. Finally, there is 4) argumentum adjuditium, which con
sists in employing proofs drawn from some one of the sources
of knowledge or probability. This is the only one of all which
advances and instructs us ; for if from respect I dare not con
tradict, or if I have nothing better to say, or if I contradict
myself, it does not follow that you are right. I may be modest,
ignorant, deceive;!, and you prove yourself to be mistaken also.
Tli. It is doubtless necessary to make a difference between
what is proper to be said and what is truly to be believed. Yet
as the majority of truths may be boldly maintained, there is
some prejudice against an opinion that it is necessary to con
ceal. The argument ad ignorantiam is valid in cases of pre
sumption where it is reasonable to hold to an opinion till the
contrary is proved. The argument ad ho mi item has this effect,
that it shows that one or the other assertion is false and that
truth, this conception passed into the philosophical and religious thinking
and life of the Christian Church, and became especially prominent in the
teachings of the Mediaeval Mystics. On this historical development cf. Win-
delband, Hist, of Philos., trans, by Tufts, pp. 119 tsq., 227 tsq., 249 sq., ZWsq.;
Zeller, Philos. d. Griech., III., 2 [Vol. 6], 413 tsq., Gil sq., 854, note 4, 3d ed.,
1881 ; Benn, Greek Philosophers, 2, 311 sq.
In a modified form this intuition of divine things became what the Church
fathers and the theological and philosophical writers of the Middle Age termed
the lumen yratise, " the light of grace," the supernatural light given through
divine inspiration, in opposition to the lumen natarale or " natural light," Ihe
rational knowledge given by nature to all men as such. Cf. Neiv Essat/s,
Bk. I., chap. 1, § 21, Th., ante, p. 71; Gerhardt, Leibniz, philos. Schrift.. 6,
4945g., 503 sq.; Hamilton's Reid, Note A, § V., IV., 1, note t, Vol. 2, p. 7(53,
§ VI., 20-22, 25-26, pp. 776-778, 54, p. 785, 8th ed., 1880. — TR.
CH. xvn] ON HUMAN UNDERSTANDING 577
the opponent is deceived whatever way he takes it. We might
bring yet other arguments which are used, for example the
one we might call ad vertfginem, when we reason thus : if this
proof is not received we have no means of attaining certainty
upon the point in question, which we take as an absurdity.
This argument is valid in certain cases, as if any one wished
to deny primitive and immediate truths, for example, that any
thing can be and not be at the same time, or that we ourselves
exist, for if he we.'e right there would be no means of knowing
anything whatever. But when certain principles are produced
and we wish to maintain them because otherwise the entire
system of some received doctrine would fall, the argument is
not decisive; for we must distinguish between what is neces
sary to maintain our knowledge and between what serves as a
foundation for our received doctrines or practices. Use was
sometimes made among jurisconsults of probable reasoning in
order to justify the condemnation or torture of pretended sor
cerers upon the deposition. of others accused of the same crime,
for it was said: if this argument falls, how shall we convict
them? And sometimes in a criminal case certain authors
maintain that in the facts where conviction is more difficult,
more slender proofs may pass as sufficient. But this is not a
reason. It proves only that we inust employ more care, and
not that wre must believe more thoughtlessly, except in the
case of extremely dangerous crimes, as, for example, in the
matter of high treason, wrhere this consideration has weight,
not to condemn a man, but to prevent him from doing harm ;
so that there may be a mean, not between guilty and not guilty,
but between condemnation and banishment in the judgments,
where law and custom admit it. Use has been made of a similar
argument in Germany for some time in order to give color to
the coining of bad money; for (they say) if we must keep to
the prescribed rules, we cannot coin it without loss. We must
be allowed then to debase its alloy. But besides the fact that
we must diminish the weight only and not the alloy or super
scription the better to obviate frauds, we suppose a practice
necessary which is not so ; for no command of heaven nor any
human law exists obliging those who have no mine nor occa
sion to have silver in bars to coin money ; and to make money
out of money is a bad practice which naturally carries deterio-
2 P
578 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
ration with it. But how (they say) shall we exercise our
regale in coining it ? The reply is easy. Content yourselves
with coining a little from good silver, even at a small loss, if
you think its coinage a matter of importance to yourselves,
since you have no need nor right to flood the world with
debased small coin.
§ 23. Ph. After having said a word concerning the relation
of our reason to other men, let us add something about its
relation to God, which makes us distinguish between what is
contrary to reason and what is above reason. Of the first class
is everything which is incompatible with our clear and dis
tinct ideas ; of the second is every thought whose truth or
probability evidently cannot be deduced from sensation or
reflection by the aid of reason.1 Thus the existence of more
than one God is contrary to reason, and the resurrection of the
dead is above reason.
Th. I find something to say regarding your definition of
that which is above reason, at least if you connect it with the
received use of this phrase ; for it seems to me that from the
manner in which this definition is couched, it goes too far in
one direction and not far enough in the other ; and if we fol
low it, all that of which we are ignorant and which in our
present condition we are unable to know, would be above
reason, for example, that a given fixed star is greater or
less than the sun ; again, that Vesuvius will send out fire in
such a year ; these are facts the knowledge of which is beyond
us, not because they are above reason, but because they are
beyond our senses ; for we could very well judge of them, if
we had more perfect organs or more information about the
circumstances. There are also difficulties which are beyond
our present faculty, but not beyond reason as a whole ; for
example, there is no astronomer here below who can calculate
the detail of an eclipse in the space of a pater and without
taking the pen in hand, yet there are perhaps genii to whom
that would be mere play. Thus all things might be made
known or practicable by the aid of reason, by supposing more
information concerning the facts, more perfect organs, and a
more elevated mind.
i Cf. Locke, Exam, of Malebranche, § 53, Philos. Wks., Vol. 2, p. 455 (Bohn's
•ed.).-TR.
CH. xvn] ON HUMAN UNDERSTANDING 579
Ph. This objection ceases if I understand my definition not
only of our sensation or reflection, but also of that of every
other possible created spirit.
Th. If you take it so, you are right. But the other diffi
culty remains, viz. : that there will be nothing above reason
according to our definition, because God will always be able
to give the means of apprehending by sensation and reflection
any truth whatever; as in reality the greatest mysteries be
come known to us by the testimony of God which we recognize
by the motives of credibility, upon which our religion is based.
And these motives undoubtedly depend upon sensation and
reflection. The question then seems to be not whether the
existence of a fact or the truth of a proposition can be deduced
from the principles which reason uses, i.e. from sensation and
reflection, or rather the external and internal sense, but whether
a created spirit is capable of knowing the how of this fact, or
the a priori reason of this truth; so that we may say that
what is beyond reason may indeed be apprehended, but it can
not be comprehended by the means and forces of created reason,
however great and exalted it be. It is reserved to God alone
to understand it, as it belongs to him alone to assert it.1
Ph. This consideration appears to me a good one, and it is
i Cf. Theodicee, Discours prelim., especially §§ 2, 5, 23, 56; New Essays.
Preface, ante, pp. 55, 60; Annotatiunculss subitanse. ad Tolandi librum, De
christianismo mysteriis carente, 1701, Dutens, Leibnit. op. om., 5, 142, 143;
Pichler, TheoL d. Leibniz, 1, 208-225; K. Fischer, Gesch. d. n. Philos., Bd. II.,
Leibniz, 3d ed., pp. 541-547.
According to Leibnitz, reason and faith are not absolutely opposed. Reason
must be capable of apprehending the supernatural as fact, even though in its
present stage of development — and perhaps in all its development — it may
never be able to comprehend it exhaustively. The supernatural, while it may
be outside of and beyond any present or future possible finite experience, is
riot then contrary to reason. In fact, to be apprehended or accepted as fact
at all, it must present such intrinsic rationality as is sufficient to induce be
lief, i.e. it must show itself to be intrinsically possible and not contrary to
any well-established knowledge. In this sense it is not wholly above reason, —
if it were, it would not at all concern us, — and may therefore become a part
of the sum-total of our knowledge. The contention of both Leibnitz and
Locke is, in fact, that the opposition is not between reason and faith, but
rather between reason and unfounded authority. Leibnitz rejects entirely
both belief based on blind submission to mere authority, and that ultra-
rationalism which refuses to admit the existence of anything not coming
entirely within the range of experience, particularly that experience which
is sensuous and individual and excludes that which is spiritual and uni
versal. — TR.
580 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
thus that I wish my definition to be understood. This same
consideration confirms me also in my present opinion that the
manner of speaking which opposes reason to faith, although it
has weighty authority, is improper ; for it is by reason that
we verify what we must believe.1 Faith is a firm assent, and
assent, regulated as it should be, can only be given upon good
reasons. Thus he who believes without any reason for be
lieving may be in love with his fancies, but it is not true that
he seeks the truth, nor that he renders lawful obedience to his
divine Master, who would have him make use of the faculties
with which he has enriched him in order to preserve him from
error. Otherwise if he is in the good way, it is by chance ;
and if in the bad, it is by his fault, for which he is accountable
to God.
Tli. I commend you strongly, sir, whnn you wish faith to
be grounded in reason : without this why should we prefer
the Bible to the Koran or to the ancient books of the Brahmins ?
Our theologians also and other learned men have clearly recog
nized it, and it is this which has caused us to have such fine
works concerning the truth of the Christian religion, and so
many excellent proofs as have been put forward against the
heathen and other unbelievers, ancient and modern. Wise
persons also have always regarded as suspicions those who
have maintained that it was not necessary to trouble them
selves about reasons and proofs when it was a question of
belief; an impossibility in fact unless to believe signifies to
recite or repeat or to let pass without troubling themselves, as
many people do, and as indeed is the character of some nations
more than others. This is the reason why, when some Aristo
telian philosophers of the fifteenth or sixteenth century, whose
remains were still extant a long time after (as we may judge
by the letters of the late Mr. Xaude2 and the Naudeana),
1 Gerhardt reads: "car c'est par la raison que nous verifions ce que nous
devons croire." Erdmann, Jacques, and Janet read : " car c'est par la raison
que nous devons croire." — TR.
2 Gabriel Naude', lGOO-l(>r>3, a celebrated French scholar, bibliographer and
librarian, who at first studied medicine and was physician to Louis XIII, but
who afterwards devoted himself entirely to literary and library work. He
was the creator of the celebrated Bibliotheque Mazarine. His Xaiide<w«, a
collection of anecdotes drawn from his conversations, appeared at Paris, 1701.
— TR.
CH. xvii] ON HUMAN UNDERSTANDING 581
desired to maintain t\\ro opposite truths, one philosophical, the
other theological, the last Lateran Council under Leo X was
right in opposing them, as I think I have already remarked.1
And a dispute wholly similar was raised at Helmstadt in
former times between Daniel Hofmann, a theologian, and
Corneille Martin, a philosopher, but with this difference, that
the philosopher reconciled philosophy to 'revelation and the
theologian wished to decline its use. But the Duke Julius,
1 Cf. Theot.lice ', Discours prelim., §§7, 8, 11. The "Aristotelian philoso
phers " here referred to, were divided into two schools, the Alexandrists and
the Averroists, according as they followed the interpretation of Aristotle
given by Alexander of Aphrodisias, c. 200, or Averroes, 1120-1198. Both
schools denied the immortality of the individual soul; the Averroists ground
ing their denial on, and finding a compensation for such immortality in, the
unity of the intellect — the rationally active part of the soul (i/oO?) — in all
men ; while the Alexandrists regarded individual souls, including this rational
part, as naturally mortal.
Both schools were opposed and condemned by the Church, and the theory
of " the double truth " (philosophical truth having its source in natural reason,
theological in a supernatural revelation), held by both schools as a shield to
protect them, in the exposition and dissemination of their views, from the
interference and persecution of the Church, was adjudged heretical in the
decree " Apostolic! Regiminis "of the fifth Lateran Council of December 11),
1512, under Leo X. This theory in the case of many of its advocates was, no
doubt, the natural and " honest expression of the inner discord " resulting
from the opposition of the two then prevalent authorities, Greek philosophy
and religious tradition.
Chief among those who advocated this theory of "the twofold truth"
was Pietro Pomponaxxi, 14(12-1525, an Italian physician and philosopher, in
his time one of the most sagacious and subtle interpreters of Aristotle of the
Alexandrian school. He maintained, in his Trastatns de inimortalitate animi,
Bologna, ir>lf>, 8vo, that none of the reasons assigned for the dogma of immor
tality were categorically demonstrative, and that therefore the doctrine must
depend upon revelation. When accused of heresy, he stoutly asserted his in
nocence, saying that he taught nothing contrary to the belief of the Church,
but simply expounded Aristotle, and adding that he denied as a Christian
what he affirmed as a philosopher. He attempted to discover a deeper foun
dation for the theory of "the twofold truth," through the recognition of the
twofold nature of reason, the speculative and the practical, the former
furnishing the basis of philosophy, the latter that of theology and ethics.
On the whole subject, cf. M. Maywald, Die Libre r. d. zii'e'fachen Wahr-
heit, Berlin, 1871; Windelband, Hist, of Philox., trans, by Tufts, pp. 318 sq.,
339 ,SY/., 359; Piinjer, Gesch. d. christ. Religionxphilos., 1, 28-29. 37, Eng. trans.,
1,39 sq., 50-52; Stockl, Gesch. d. Philos. d. Mittelalters. Ill [Vol. 4], 202-207,
and for an account of Pomponazzi and his philosophy, ibid. 213-244 ; cf. also
L. Ferri, La Psicoloyia di P. Pomponazzi, Rome, 1877. For the decree
"Apostolic! Regiminis." cf. Acta Condi. Rey., Vol. 34, p. 333, Paris, Ki44,
37 vols , fol.: Labbe, Condi. , torn. 19, col. 842; Stockl, op. cit., Ill [Vol.4],
2(Xi, n. 1. — TR.
582 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
founder of the university, decided for the philosopher.1 It is
true that in our time a person of the most exalted position
said that in a matter of faith he must put out his eyes in order
to see clearly, and Tertullian says somewhere : this is true,
because it is impossible : 2 it must be believed, for it is an
absurdity. But if the intention of those who explain them
selves in this way is good, these expressions are always ex
aggerated and may do harm. St. Paul speaks more justly
when he says that the wisdom of God is foolishness with
men; because men judge of things only according to their
experience, which is extremely limited, and everything not
agreeing therewith appears to them an absurdity. But this
judgment is very rash, for there is indeed an infinite number
of natural things which would pass with us as absurd, if they
were told us, as the ice which was said to cover our rivers
appeared to the king of Siam. But the order of nature itself
not being of any metaphysical necessity, is grounded only in
the good pleasure of God, so that he may deviate therefrom
by the superior reasons of grace,3 although he must proceed
therein only upon good proofs which can come only from the
testimony of God himself, to which we must defer absolutely
when it is duly verified.
1 Of. Theodicee, Discours prelim. § 13. On the controversy itself, extend
ing from 1598-1601, cf. Piinjer, Gesch. d. christ. Religionsphilosophie, 1, 132-
141, Eng. trans., 1, 178-190. For the fullest accounts, cf. G. Thomasins, De
Controversial Hofmanniana, Erlangen, 1844, and E. Schlee (who gives the
external history with complete references to the literature), DerStreit d. Dan.
Hofmann «. d. Verhdltniss d. Philos. z. TheoL, Marburg, 1862. Schaarschmidt
refers to E. L. Th. Henke, Ge.org Calixtns ?*. seine Zeit, Einleitung, p. 73 sq.,
and says that Duke Julius [Henry Julius, son of the founder of the Uni
versity, and the successor of his father in the government in 1589] , who had
examined the documents in the controversy and reached a decision, did rightly
in protecting the philosopher against his opponents, who spread abroad the
most horrible calumnies concerning him, and treated him in general very
harshly. — TR.
2 Cf. Tertullian, De Came Christi, chap. 5: " Mortuus est dei films: prorsus
credibile est, quia ineptum est. Et sepultus resurrexit; certum est, quia im-
possibile est." Leibnitz also refers to this passage in the Theodicec, Discours
prelim. § 50. — TR.
3 Cf. ante, p. 402, note 1. — TR.
CH. xvin] ON HUMAN UNDERSTANDING 583
CHAPTER XVIII
OF FAITH AND REASON AND THEIK DISTINCT LIMITS
§ 1. Ph. Let us accommodate ourselves meanwhile to the
received mode of speech, and suffer faith to be distinguished in
a certain sense from reason. It is proper that this sense be very
accurately explained and the limits existing between these two
things be established ; for uncertainty regarding these limits
has certainly produced in the world great disputes and perhaps
caused even great disorders. It is at least manifest that, until
these have been determined, it is in vain for us to discuss, since
we must employ reason in discussing faith. § 2. I find that
each sect uses reason with pleasure so long as it believes it
can derive therefrom any aid : but as soon as reason fails, they
cry out : it is an article of faith, which is above reason. But
the opponent could make use of the same evasion if any one
took it upon himself to argue against him, unless we indicate
why that would not be permitted him in a case seemingly
parallel. I suppose that reason is here the discovery of the
certitude or probability of propositions drawn from knowledge
which we have acquired by the use of our natural faculties,
that is to say by sensation and by reflection ; and that faith is
the assent given to a proposition based upon revelation, that is
to say upon an extraordinary communication from God which
has made it known to man. § 3. But a man inspired of God
cannot communicate to others any new simple idea, because lie
uses only words or other signs which awake in us the simple
ideas that custom has attached to them or their combination ;
and whatever new ideas St. Paul received when he was carried
up to the third heaven, all that he could say was : they are
things eye hath not seen, ear hath not heard, and which have
never entered into the heart of man.1 Suppose there were creat
ures in the planet Jupiter provided with six senses and that
God in a supernatural way gave to a man among us the ideas of
this sixth sense, he could not by means of words make them
1 1 Cor. 2, 9. — TR.
584 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
spring up in the minds of other men.1 We must then distin
guish between original and traditional revelation. The first is
an impression which God makes immediately upon the mind,
and to this we can fix no limits ; the other comes only by the
ordinary means of communication and cannot give new simple
ideas. § 4. It is true, however, that the truths which may be
discovered by reason can be communicated to us by a tradi
tional revelation, as if God had desired to communicate to men
geometrical theorems, but this would never amount to so great
a certainty as if we had their demonstration drawn from the
connect ion of ideas. It is also as if Noah had a more certain
knowledge of the deluge than that which we have acquired
from the book of Moses and as if the assurance of one who has
s?en that Moses actually wrote it and that he did the miracles
which justify his inspiration was greater than ours. § 5. This
it is which makes it impossible for revelation to go against the
clear evidence of reason, because whenever the revelation is
immediate and original we must know with certainty that we
are not deceived in attributing it to God and that we compre
hend its meaning; and this evidence can never be greater than
that of our intuitive knowledge ; and consequently no proposi
tion can be received as divine revelation when it is contradic
torily opposed to this immediate knowledge. Otherwise there
would no longer remain any difference in the world between
truth and falsehood, any measure of the credible and incredi
ble. And it is inconceivable that a thing comes from God, this
beneficent author of our being, which received as true must
overturn the foundations of our knowledge and render all our
faculties useless. § 6. Thosa who have revelation only medi
ately, or by tradition from mouth to mouth or by writing, have
again more need of reason to assure themselves of it. § 7.
Meanwhile it is always true that the things which are beyond
what our faculties can discover are the ptoper matters of faith,
1 Cf. Lessing's amplification of a similar thought, perhaps suggested by this
passage of Leibnitz, in his Fragment: Da.s.s nielir «/.s fiinf Slnne fiir den
Meiischen xein konnen, Sdnintt. Schrift, ed. Lachmann-Maltzahn, Leipzig,
1853-1857, Vol. 11, Pt. 2, p. 458. On the relation of Lessing to Leibnitz, cf.
Zimmermann, Leibniz und L?s*iny, Eine Studie, Wieii, 1855; Piinjer, Gesch.
d. christ. Religionsphilosophie, 1,421^125, Eng. trans., 1, 5HH-570; Ptieiderer,
Religionsphilosophie, 1, 143, Eng. trans., 1, 145-146; K. Fischer, Gesch. d. n.
Philos., Bd. II., Leibniz, 3d ed., pp. 617-619. — TR.
CH. xvni] ON HUMAN UNDERSTANDING 585
as the fall of the rebellious angels, the resurrection of the
dead. § 9. Here we must listen solely to revelation. And
even as regards probable propositions an evident revelation
will determine us against the probability.
Th. If you take faith as that which is grounded in the
motives of credibility (as they are called) and detach it from
the internal grace which immediately determines the mind,
all that you say, sir, is beyond dispute. It must be admitted
that there are many judgments more evident than those de
pending upon these motives. Some are urged on by them far
ther than others, and there are indeed many persons who have
never known them and still less considered them and who con
sequently have not even that which might pass as a motive of
probability. But the internal grace of the Holy Spirit imme
diately supplies it in a supernatural way, and this it is which
produces what the theologians properly call a divine faith.
It is true that God never gives it except when the belief it
produces is founded in reason; otherwise he would destroy
the means of knowing the truth and open the door to enthu
siasm ; but it is not necessary for all who have this divine
faith to know these reasons and still less to have them always
before their eyes. Otherwise simple-minded people and idiots,
to-day at least, would never have the true faith, and the most
enlightened would not have it when they were most in need
of it, for they cannot always remember the reasons for their
belief. The question of the use of reason in theology has
been one of the questions most discussed, both between the
Sociiiians and those who may be called Catholics in a general
sense, and between the Reformers and the Evangelicals, as
those are named by way of preference in Germany whom many
inaptly call Lutherans. I remember to have read once a M eta-
physic of one Stegmann,1 a Socinian (a different man from
Joshua Stegmann,2 who himself wrote against them), which so
1 Cf. Theodicee, Discours prelim., § 1(5, where Leibnitz refers to him as
Christopher Stegmann, a Socinian. He was the youngest brother of Joachim
Stegmann, also a Socinian and author of many works on mathematics and
theology, who died in exile at Clausenburg in Siebenbiirgen in 1032. Christo
pher wrote a work entitled Dyas philosophica, which is, perhaps, the " Meta-
physic" of which Leibnitz here speaks. F >r further account of him, cf.
Jocher, Allgeineines Gelehrten- Lexicon, Pt. IV., 794, Leipzig, 1750. — TR.
2 Joshua Stegmann, 1588-1(532, a Lutheran divine, was Professor at Leipzig,
Wittenberg, and Kinteln, and the author of mary theological works, and of
586 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
far as I know has not yet been printed ; on the other hand, one
Kessler,1 a theologian of Saxony, has written a Logic and some
other philosophical treatises expressly opposed to the Socinians.
We may say in general, that the Socinians are too quick to
reject everything which is not conformed to the order of
nature, even when they cannot prove absolutely its impossi
bility. But their opponents also sometimes go too far and
push mystery to the verge of contradiction ; in which they
injure the truth they try to defend. I was surprised to see
once in the " Summa Theologiae " of Father Honore Fabry,2
who otherwise was one of the most clever of his order, which
he denied in divine things (as do also some other theologians),
this great principle which states that things tvhich are identical
with a third thing are identical ivith each other. This is to give
the famous German hymn, " Ach, bleib' mit deiner Gnade " (Eng. trans, in
Lyra Germanica, 2, 120, " Abide among us with thy grace, Lord Jesus, ever
more "). He was opposed to the Socinians or Photinians, and wrote against
them his Photinianismus,h. e. Succincta Refutatio Errorum Photinianorwn.
quinquaginta sex disputationibus breviter comprehensa, Rinteln, 1G23, 8vo:
Frankfort, 1(543. Leibnitz mentions him again in the Theodicee, Discours
prelim., § 62. For further account of him, cf. Winer, Handbuch d. theolog.
Lit., 1, 354; 2, 748; Jocher, Allgemeines Gelehrten-Lexicon, Pt. IV., 794,
Leipzig, 1750.— TR.
1 Andreas Kessler, 1595-1643, a Lutheran divine, studied at Jena and
Wittenberg, and was pastor at Eisfeld, Eisenach, and Coburg, where he died
in consequence of a stroke of apoplexy received while preaching. He wrote
against the Socinians or Photinians his Physicse Photinianse examen, Eisfeld,
1628, Wittenberg, 1656, 8vo : Metaphysics^ Photinianse examen, 3d ed., Witten
berg, 1648, 8vo ; Logicee Photinianse examen, 2d ed., Wittenberg, 1624, 4to, new
ed. 1642, 8vo. His writings exhibit a good deal of method and exactness.
Leibnitz also refers to him in the Theodicee, Discours pre'lim., § 16. For fur
ther account of him, cf. Jocher, Allgemeines Gelehrten-Lexicon, Pt. II., 2072,
Leipzig, 1750.— TR.
2 Honore Fabri, 1607-1688, a French mathematician and philosopher, and
a Jesuit, who taught philosophy and mathematics in the college of his order
at Lyons, and later became Grand-Penitentiary at the holy office in Rome.
Among his writings are, Synopsis geometrica, Lugd., 1669; Physica sen sd~
entia rerum corporearum in decent tractatus distributa, Lugd., 1(>69; Summula
Theologies, Lyons, 1669. Leibnitz regarded him as one of the most distin
guished men of his time, and frequently mentioned him with praise. (/.
Theodicee, Pt. III., § 348; Hypoth. phys. nova, §§ 56, 59, Gerhardt, Leibniz.
philos. Schrift., 4, 208, 214, 216; Theoria motus abstracts, prope fin., ibid.,
240, and Appendix thereto, containing a letter of Fabri to Leibnitz, ibid., 241-
244, and of Leibnitz to Fabri, ibid., 244-261 (also Gerhardt, Leibniz, math.
Schrift., II., 2 [Vol. 6], 81-98). For another Appendix to a letter of Leibnitz
to Fabri, cf. Gerhardt, Leibniz, math. Schrift., II., 2 [Vol. 6], 98-106, trans.
infra, Appendix, pp. 699 sq. — TR.
CH. xvin] ON HUMAN UNDERSTANDING 587
a gained case to the opponent without thinking and to deprive
all reasoning of certainty. We must say rather that this
principle is badly applied. The same author rejects in his
philosophy the virtual distinctions, which the Scotists put
into created things, because they reversed, he says, the prin
ciple of contradiction : and when the objection is made to him
that these distinctions must be admitted in God, he replies
that faith orders it. But how can faith order that, whatever
it be, which reverses a principle without which all belief,
affirmation, or negation would be vain ? Two propositions true
at the same time must therefore necessarily not be wholly
contradictory; and if A and C are not the same thing, it is
clearly necessary that B which is identical with A be taken
otherwise than B which is identical with C. Nicolaus
Vedelius,1 a professor at Geneva and afterward at Deventer,
once published a book entitled "Rationale Theologicum," to
which Jean Musaeus,2 a professor at Jena (which is an Evan-
1 Cf. Theodicee, Discours prelim., §§ 20, 67. Nicolas Vedel, a German
Reformed (Calvinistic) divine, was Professor of Philosophy and minister at
Geneva, of Theology and Hebrew at Deventer, 1630-1638, and of Theology
at Franeker from 1638 till his death in 1642. He was a great adversary of
the Arminians, and wrote against them his De Arcanis Arminianismi,
Leyden, 1632-1634. His Rationale theologicum, seu de necessitate et vero iisu
principiorum rationis ac philosophise in controversies theologicis, lib. tres,
Geneva, 1628, was attacked by Earth. Nihus, 1584-1657, in his Morosophus
sen Vedelius in suo rationali prorsus irrationalis, Cologne, 1(546, as well as
by Museeus. On the controversy between Vedelius and Musseus, cf. Piinjer,
Gesch. d. christ. Religionsphilosophie, 1, 118-124, Eng. trans., 159-167. For
further account of Vedel, cf. Winer, JIandbuch d. theol. Lit., 1, 353, 375, 565;
J. P. Niceron, Mem. d' homines, Vol. 33, 1736. — TR.
2 Cf. Theodicee, Discours prelim., §§ 20, 67. Johannes Musaeus, 1613-1681,
a Lutheran divine, was Professor of History, 1642-1646, and of Theology, 1646
till his death, at Jena. He was the greatest Lutheran divine of his century
after J. Gerhard, 1582-1637, and Geo. Calixtus, 1586-1656. He distinguished
between theology and the confessions and favored liberty of scientific and
theological researches. He was everywhere acknowledged as a very learned
man, and his writings are distinguished by philosophical acumen so that he
was accused of " magis philosophari quam quod loquatur eloquia Dei." He
wrote in defence of Christianity against Herbert of Cherbury, 1581-1(548, a
work entitled De luminis natures et ei innixss tlieologisz naturalix insufficient ict
ad salutem, Jena, 1(567; against Spinoza, his Tractatus theolog.-polit., etc.,
Jena, 1674 (on Musreus and Spinoza, cf. Piinjer, Gesch. d. christ. Religions-
philos., 1, 322-323, Eng. trans., 1, 435). His De usu principiorum rationis et
philosophise, in controversies theologicis lib. tres Nic. Vcdelii Rationali Theo-
logico potissimum oppositi appeared at Jena, 1(544; 2d ed., 1665. For further
account of Musaeus, cf. Herzog, Realencyklopadie, 2d ed., 10, 376-380. — TR.
588 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
gelical university in Thuringia), wrote another book in oppo
sition upon the same subject, i.e. upon "The Use of Reason in
Theology." I remember to have considered these formerly,
and to have remarked that the principal controversy was ob
scured by incidental questions, as when it is asked, what a
theological conclusion is, and whether it is necessary to judge
of it by the terms which compose it, or by the means which
prove it, and consequently whether Occam l was right or not in
saying that the knowledge of one and the same conclusion is
the same whatever 2 the means employed to prove it; and he
delays upon a multitude of other minutiae of still less import
ance, which concern only terms. Meanwhile Musaeus agreed
with him that the principles of reason necessary by a logical
necessity, i.e. the opposite of which implies a contradiction,
must and may be employed safely in theology ; but he had
.reason to deny that what is only necessary by a physical neces
sity (i.e. founded upon induction from that which is customary
in nature, or upon natural laws which, so to sp:>ak, are of divine
institution) is sufficient to refute the be1 let' in a mystery or
miracle, since it depends upon God to change the ordinary
course of things. Thus it is according to the order of nature
that we may be certain that one and the same person cannot
be at the same time a mother and a virgin, or that a human
body cannot fail to be obvious to the senses, although the
contrary of both may be possible to God. Vedelius also
appears to agree to this distinction. But we sometimes dis-
1 William of Occam, the date of whose birth is unknown, and who died at
Munich in 1347, renewed and developed Nominalism in the form of Tcnni-
nism, the Termini (concepts) being subjective signs of really existing things,
and not mere names — flatus vocis — as so frequently regarded. The relations
of his philosophy to subsequent thinking are well set forth by Windelband-
Tufts, Hist, of Philos., pp. 312, 315, 325 sq., 342 sq. For Leibnitz's view of
his Nominalism, cf. DC stilo philos. Nizolii, § 2K, Erdmann, (>8 h-(>!> b ; Ger-
hardt, 4, 157-158. On his life and philosophy, cf. Stockl, Gcsch. d. Philos. d.
Mittelalters, II., 2 [Vol. 3], i)8fi-10'Jl ; Haureau, Hist. d. la Philos. scolastlque,
II., 2 [Vol. 3], 35<>-430: Prantl, Gcsch. d. Logik, 3, 327-420.— TR.
2 Gerhardt reads : " quel moyen qu'on employe," etc. ; Erdmann, Jacques,
and Janet read: " que le moyen qu'on emploie," etc., i.e. "as the means
employed," etc. Schaarschmidt, in his translation, follows the reading of
Erdmann, Jacques, and Janet, and says in his note to the passage : "Dass wir
mit andern Worten bei unserm Schlussverfahren uns nothwendig im Cirkel
bewegten," i.e. " That we, in other words, in our reasoning, necessarily moved
in a circle." The correct reading can be determined only by the exact lan
guage of Occam, which thus far I have been unable to find. — TR.
CH. xvin] ON HUMAN UNDERSTANDING 589
pute about certain principles, whether they are logically
necessary, or only physically so. Such is the dispute with
the Sociniaris, whether substance can be multiplied when the
individual essence does not exist; and the dispute with the
Zwinglians, whether a body can be only in one place. Now
we must admit that every time that logical necessity is not
demonstrated, we can presume in a proposition only physical
necessity. But it seems to me that a question remains, which
the authors of whom I have just spoken have not sufficiently
examined, namely this : Suppose that on one side we find the
literal sense of a text of Holy Scripture, and on the other a
great appearance of logical impossibility, or at least an ad
mitted physical impossibility, is it more reasonable to deny the
literal sense or the philosophical principle ? It is certain that
there are passages where to abandon the letter occasions no
difficulty, as when Scripture gives hands to God and attributes
to him anger, penitence, and other human affections ; other
wise it would be necessary to array ourselves on the side of
the anthropomorphists, or of certain English fanatics who
believe that Herod was really change;! into a fox when
Jesus Christ called him by that name. It is here that the
rules of interpretation are in place, and if they furnish nothing
which combats the literal sense in order to favor the philo
sophic maxim, and if in addition the literal sense has nothing
which attributes to God any imperfection, or entails any
danger in the practice of piet}-, it is safer and indeed more
reasonable to follow it. These two authors whom I have just
named dispute further upon the undertaking of Keckermann,1
1 Bartholomew Keokermann. 157.°>-1(>09, a Semi-Ramist, was Professor of
Hebrew at Heidelberg, and, from 1(501, of Philosophy at ihe Gymnasium at
Dantzic. He was the author of many compilations, made for 'the use of his
pupils in the gymnasium, in which he presented all the sciences in a method
ical and systematic form. His Opera otnuia appeared at Geneva, 1614, 2
vols., fol. Leibnitz refers to him in the same connection in the T/i.eodicee,
Discours prelim., § 5<). For further account of him, <•/. \Y. Gass, Gexch. d.
protest aniischen Dogmatik inihrcm Z usammenhanr/e in it d. Theoloyic, Vol. 1,
pp. 408 sq. Piinjer, Gesch. d. chrfxt. Religionsphilos., 1, 118, 127, 128, Eng.
trans., 1, ir»8, 170, 172, briefly refers to him.
According to Schaarschmidt, Keckermann's proof of the Trinity from
reason, which is quite closely connected with that of Lully, as Lully's with
the thoughts of Augustine, is found in his 8y sterna fss. theologize (1st ed.,
1(502; 2d ed., Hanoviaj, 1(507), chap. 3, pp. 20 sq., 3d ed., Hanovire, 1(515. In
the introduction Keckermann expresses himself very decidedly. " Fateor
590 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
who wished to demonstrate the Trinity by reason, as Raymond
Lully 1 had also tried to do formerly. But Musaeus acknowl
edged with sufficient fairness that if the demonstration of the
Reformed author had been valid and just, he would have had
nothing to say on the subject ; that he would have been right in
maintaining as regards this article that the light of the Holy
Spirit might be illumined by philosophy. They have also
discussed the famous question, whether those who, without
any knowledge of the revelation of the Old or Xew Testament,
died in the opinions of a natural piety, could have been saved
by this means and obtained the remission of their sins ? We
equidern ultro, circa mysterium de ss. Triade, ad id esse omnem intellectum
humanum, quod est oculus vespertilionis ad solem," etc. Keckermann's de
monstration was refuted by Musaeus in the " Dissertatio altera," appended to
his De itsu princip. rationis at philos. in controversiis thcolof/icix, 2d ed., Jena?,
1665. — TB.
1 Raymond Lully, 1234 or 1235-1315, best known as the inventor of the
" Great Art," attempted to demonstrate against the assertions of the Aver-
roists, the inherent rationality of the doctrines of Christianity. His Opera
oinnia, 10 vols. (Vols. 7 and 8 probably' never printed), fol., appeared at
Mainz, 1721-1742. For an account of his life and philosophy, cf. Stockl,
'Gesch. d. Philos. d. Mittelalters, II., 2 [Vol. 3], 924-952; Erdmann, Grund. d.
Gesch. d. Philos., § 20(1, Vol. 1, pp. 375-398, Eng. trans., 1, 447-468; Neander,
Hist, of the Christ. Relig. and Church, 4, 65-71, 42(5, 435 sq. ; for his Logic,
cf. Prantl, Gesch. d. Logik im Abendlande, 3, 145-177. Cf. also an article
by Delecluse in the " Revue de Deux Mo rides," 1840.
Lully occupied himself much with the proof of the Trinity, discussing it,
according to Schaarschmidt, in his Qusestiones [Disputatio ErimitSB et Ray-
miindi — Erdmann] super lib. Sententiarum, Lib. I., quaest. 6; Disputatio Jidelis
(catholici) et infidelis, pp. 2, 3: and especially in the Disputatio Jidei ct int>>l-
lectus, Pt. I., where the question of the demonstrability of the Trinity is con
sidered in detail, and Pt. II., where the proof is attempted. Schaarschmidt
thinks that Leibnitz probably has in mind this last work. All three works
are found in Opera, Vol. 4, ed. Mainz, 1729. Stockl, op. cit., II., 2 [Vol 3], 942-
944, gives an account of Lully's argument on the Trinity, based chiefly on the
Articuli jidei sacrosanctse, found in the collection of Lully's works entitled
Opera ea quse ad inventam a Lullo artem universcdcm pertinent, Argentorati,
1598, 1607, and 1617, and also in Opera, Vol. 2, ed. Mainz, 1722. In his list of
Lully's works, Stockl cites the following which discuss the Trinity: Liber con-
tradictionis inter Raymundum et Averroistam de centum syllogism is circa
mysterium Trinitatis; Liber de substantia et accidente in quo probatur
Trinitas. Cf. also Neander, op. cit., 4, 4(55.
For Leibnitz's own views on the Trinity, cf. his Defensio Trinitatis per
nova reperta logica, contra Epistolam Ariani, Dutens, Leibnit. op. out., 1, l(i-
16; Dux Epist. ad Lceflerum de Trinitate et Definitionibus Mathentaticis
circa Deum, Spiritus, etc., Dutens, op. cit., 1, 17-23; Remarques sur le fivre
d'un Antitrinitaire Anglois, etc., Dutens, op. cit., 1, 24-27, and Feller, Leibnit.
Miscellanea, No. IV., pp. 8-15; The'odicee, Discours prelim., § 22: Letter to
M. B., 1696, Feller, op. cit., No. VIII., pp. 26 sq. — TR.
CH. xvin] ON HUMAN UNDERSTANDING 591
know that Clement of Alexandria, Justin Martyr, and St.
Chrysostom to a certain extent were inclined thereto,1 and
indeed I once showed Pelisson - that a number of excellent
doctors of the Roman church, far from condemning non-opin-
ionative Protestants, even desired to save the heathen and to
maintain that the persons of whom I have just spoken could
have been saved by an act of contrition, i.e. penitence grounded
in the love of benevolence, in virtue of which we love God
above everything, because his perfections render him supremely
lovable. This brings it about that afterwards we are led with
all our hearts to conform to His will and to imitate His per
fection in order the better to unite ourselvres with Him, since it
appears right for God not to refuse his grace to those who hold
such views. Xot to speak of Erasmus and of Ludovicus Vives,3
1 Clement of Alexandria, born e. 150-160, date and place of death unknown.
Cf. Stromata (or Miscellanies), Bk. VI., chaps. 5 and (5. — Justin Martyr,
c. 114-c. 163. Cf. First Apol&fjy, chap. 46; Second Apology, chaps. 8 and 13.
— John Chrysostom, c. 347-407. Clement and Justin entered the Christian
church as thinkers trained in Greek philosophy, which they regarded as the
gift of God iu preparation for the fuller light and life of Christianity — Justin
in particular through his view of the "spermatic logos," "the seed of reason
implanted in every race of men " ; while Chrysostom, trained in Greek rheto
ric and oratory, took a similar view of Greek culture as from God and not
from the evil one. All three would naturally look upon those who lived up
to the light they had as likely to receive more in due time, and to accept it
and live in it when it came. — TR.
'2 Paul Fontanier-Pellisson, 1(524-1693, born and educated a Protestant, fol
lowed at first the profession of the law, but afterwards abandoned it for that
of literature. He held several public offices, among others that of histori
ographer to Louis XIV. To obtain this position he was obliged to become a
Catholic. He published a large number of Avorks, among which was a Latin
paraphrase of the first book of the Institutes of Justinian, 1645; His to ire de
r Academic frar)(;aisejusqn'en 1652, 1653, 8vo ; Traite de I'EticJwristie, 1694,
12mo, and other religious works. He corresponded extensively with Leibnitz
on religious and theological subjects. The correspondence is contained in his
Reflexions sur IPS differends en niatiere de relit/ion, 1686, and following years,
4 vols., 12m o. Portions of the same in Dutens, Leibnitz op. om., 1, 678 sq. ;
most complete in Foucher de Careil, CEnvres de Leibniz, Vol. 1. For the
letter here referred to by Leibnitz, cf. Dutens, op. cit., 1. 681-684, Foucher de
Careil, op. cit. 1, 55-6(5; for Pellisson's replies, cf. Dutens', op. cit., 1, 697, 700-
702, Foucher de Careil, op. cit., 1 , 90-92, 9(5-100. For account of the controversy,
cf. Guhrauer, Leibnitz, Eine Bioy., Pt. II., 35 sq. — TR.
3 Jnan Luis Vives, 1492-1540, a Spanish scholar and philosopher, a younger
contemporary and friend of Erasmus, 1467-1536, and for a time the instructor
of the Princess Mary, daughter of Henry VIII., was a persistent and success
ful opponent of scholastic Aristotelianism, and, as an advocate of the direct
study of Nature by the way of experiment, the precursor of Descartes and
Bacon. His Opera omnia appeared at Basle, 1555, 2 vols., fol., and at Valencia,
592 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
I bring forward the view of Jaques Payva Andradius,1 a
Portuguese doctor very celebrated in his time, who was one
of the theologians of the Council of Trent, and who said indeed
that those who did not agree with this view made God supremely
cruel (neque enim, inquit, immanitas deter ior ulla esse potest).
Pelisso'n found difficulty in finding this book in Paris, an indi
cation that authors esteemed in their time are often neglected
afterwards. This is what made Bayle think that many cite
Andradius only upon the testimony of Chemnitius,2 his antag
onist. This may indeed be so, but for myself I had read him
before quoting him ; and his disputes with Chemnitius made
him celebrated in Germany, for he had written in behalf of the
Jesuits against this author, and we hud in his book some par-
1782-1790, 8 vols., fol. On his life and philosophy, cf. Sto'ckl, Gesch . d. Phllos. d.
Mittelalters, III. [Vol. 4], 285-287 ; Ueberweg-Heinze, Gexch. d. Philos., 7th ed.,
1888, Vol. 3, pp. 24, 25 ; Lange, Gesch. d. Materialist) MS, Vol. 1, p. 106, Iserlohn,
1866, Eng. trans., 1, 228, 2d ed., Boston, 1879; and Lange's article on " Vives,"
in Encykl. d. yes. Erzi»h.- a. Urtterrichtsioesen, Vol. 9, pp. 737-814. — TR.
1 Diego Payva d'Andrada, 1528-1575, a celebrated theologian of one of the
most noble Portuguese families, who, after completing his studies chiefly in
the Scriptures and the Fathers, devoted himself with zeal to missions for
instructing the ignorant, and was sent at the age of thirty-three by King
Sebastian of Portugal to the Council of Trent to assist as a theologian. There
he composed his Orthodoxarum explicationum de religionis Christianas capi-
tib/iv lib. X. udversus hsereticos, contra Chemnichun, Venetiis, 15(54, 8vo ;
and his Dcfen.no TrldentinsB fidei catholicae et inteyerrinise V. lib. compre-
henaa adrc/rxns hsereticor.'tm detestabilrs calutnnias et praeftertim Martini
G"taninicii Gerniani, Olyssipone, 1578, 4to, Ingolstadt, 1580, 8vo. In the lat
ter book he maintained the opinions of Zwingli and Erasmus on the salvation
of the heathen, in consequence of which the book was much quoted by Prot
estants. Leibnitz refers to him in this same connection in the Theodictc, Pt. I.,
§ 96 ; in an excerpt from a letter to a friend written Nov. 1697, cf. Dutens,
Leibnif . op. om., 1, 33; in Ids letters to Pellisson, Dutens, op. cif., 1, 683,
Foucher de Careil, (E nitres de Leibniz, 1, 65-66; and in his letters to Ant.
Magliabeehius, Xo. 28, 26 Nov., 6 — Dec., 1697, Dutens, op. cit., 5, 121, and to
Job. Fabrieius, Prof, at Helmstadt, No. 16, Sept. 20, 1698, Dutens, op. cit.,
5, 235. — TR.
2 Martin Chemnitz, 1522-1586, a German Lutheran theologian, a disciple of
Melancthon, 1497-1560, and said to be the ablest theologian of the period imme
diately succeeding Luther, was Professor of Theology at Wit temberg, 1551-1554,
and then for thirty years pastor at Brunswick. To him more than to any other
the Lutheran church owes its purity of doctrine and compact organization.
His Loci Theolof/ici. Frankfort, 1591, is one of the best expositions of Lutheran
theology as modified by Melancthon. His greatest work, the Eramen Con-
cilii Tridentini, appeared at Frankfort in four parts, 15(>5-1573, again in 1585,
4 vols., fol., and in later eds. For further account of Chemnitz, cf. Schenkel's
article in Herzog, Roale.nci/clop., 2d ed., Leipzig, 1878, Vol. 3, pp. 184-192.
Leibnitz refers to him also in the T/icodice*, Discours prelim. § 67. — Tu.
GH. xvin] ON HUMAN UNDERSTANDING
ticulars touching the origin of this famous society. I have
remarked that some Protestants called those Andradians, who
were of his opinion upon the subject of which I have just spoken.
There have been authors who have written expressly upon the
salvation of Aristotle upon the basis of these same principles
with the approbation of the Censors. The books also of Collins l
in Latin and La Mothe le Vayer 2 in French on the salvation of
the heathen are well known. But a certain Franciscus Puccius 3
1 Francesco Collio — Latin, Collius (" Collins " being a misprint for " Col
lins " in all the editions of Leibnitz's text) — was an Italian theologian of
great learning, a doctor of the Ambrosian College at Milan, and Grand Peni
tentiary of the diocese of Milan from 1031 till his death in 1040. In his De a.ni-
mabuspaffanorum, 2 vols., 4to, Mediol. 1622-1023, 2d ed., 1738-1 740, he discussed
the question of the eternal salvation of the pagans, deciding as to the fate of
individuals on the ground of their knowledge of divine things, their moral
life, sentiments and writings, and the testimony regarding them given by eccle
siastical and profane writers. He considers Aristotle as unsaved. Dnpin,
Bibl. dvs Ant. ecdes., 1711, torn. 17, pp. 10i)-110 sq., gives a long abstract from
this work, and an estimate of its character and value. Cf. also Tiraboschi,
Storia della Letter at araltaliana, Vol. 14 [Tomo VIII, Parte Prima, ed. Rome,
1782-1784], pp. N>7-l(i8, Milan, 1824. — TR.
- Francois de La Mothe le Vayer, ir>88-1672, a French writer and philos
opher, was from 1(552-1000 the instructor of Louis XIV. of France, for whom
he composed many elementary treatises on various subjects of study. The book
here referred to by Leibnitz is his De la vert a des pa'iens, Paris, 1C42, 4 to.,
3d ed., 1(547. The subject is treated in the conclusion of Pt. L, of. CEuvres,
Vol. 1, p. 582, Paris, A. Courbe, 10(52. The best ed. is that published at Dres
den, 175(5-175!), 7 vols. in 14, 8vo. The De la vertu des pa'iens — avec les preuves
des citations mises sous le texte — is found in Vol. 5, pp. 1 xq. of this ed.
Le Vayer goes back to the Church Fathers and later ecclesiastical writers,
and gives much literature. — TR.
3 Francesco Pucci, an Italian theologian (died 1000), was led to devote him
self to theology by his participation in religious controversies at Lyons, whither
he had gone to learn commerce. Adopting mostly Protestant ideas, he went
to England, where he received an Oxford M.A. in 1574. Opposing, in his De
Jide in, D°um, quse el q wills sit, the Calvinism then ruling at Oxford, he went
to Basle and joined himself to F. Socinus, but soon returned to England in
consequence of persecution on account of his views on universal grace, put
forth in theses entitled Universum genus huinanum in ipso niatris ittero
efficaclter particeps esse ben°Jiciorum Christi et nitse innnortalift et beafse, etc.
He finally became a Catholic, 1588, and secretary of Cardinal Pompei. In his
De immortalitate natural i primi hominis ante peccatuni hecombatted certain
ideas of Socinus, and in his De Christi Salvationis efficacitate omnibus et sln-
gulis ho minibus quatenux homines mint assert io wtholica, Gouda, 15!)2, Svo,
he maintained the view that all men could be saved through the natural power
of reason, or through the natural belief in the Creator. He proposed to prove
by Scripture and the Fathers that Christ by his death made satisfaction for all
men, so that all having a natural knowledge of God will be saved, although
having no knowledge of Jesus Christ. — TR.
2Q
594 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
went too far. St. Augustine, wholly clever and penetrating as
he was, threw himself into another extreme view, even con
demning infants dying without baptism,1 and the Scholastics
appear to have been right in abandoning it ; although persons
otherwise clever and some of great merit, but of a disposition a
little misanthropic in this respect, desired to revive this doctrine
of this -Father and have perhaps exaggerated it. This spirit
also may have had some influence in the dispute between several
excessively vehement doctors and the Jesuit missionaries in
China, who had insinuated that the ancient Chinese had had
the true religion of their time and the true saints, and that the
doctrine of Confucius was in no respect idolatrous or atheistic.
It seems that there was more reason in Rome in being unwilling
to condemn one of the greatest nations without understanding it.
It is well for us that God is more philanthropic than men. I
know some persons who, thinking to show their zeal by severe
opinions, fancy that we cannot believe in original sin without
being of their opinion, but in this they are mistaken. And it
does not follow that those who justify the heathen, or others
who lack ordinary aid, must attribute it to the forces of nature
only (although perhaps some Fathers were of this opinion), since
we may maintain that God in giving them the grace exciting
an act of contrition gives them also, either explicitly or virtu
ally, but always in a supernatural way, before they die, even if
i On this and the immediate context, cf. Theodicee, Pt. I., §§ 02-95, Ft. III.,
§ 283. Augustine's view is found in his works passim. Cf., among others,
Enchir. ad Laurent., chap. 43; De nuptiis et concupiscentia, Bk. I., chap. 22,
with which cf. Contra Julianum Pelagianum, Bk. III., chap. 12 (infants under
the power of the devil on account of original sin — the " potestas diaboli " is
" peccatum originate ")> and Bk. V., chap. 44; Contra duas epist. /War/.,
Bk. IV., chap. 4 ; De peccatorum meritis et Remissione et de Baptfsino Parvu-
lorum, Bk. I., chap. 25, Bk. III., chap. 7; De peccate originate, chap. 36; De
civilate Dei, Bk. XIII., chap. 14. Cf. also Shedd, Hist, of Christ. Doct., 2, 76,
note 2, 77, note 1; Hagenbach, HIM. of Doct., ed. H. B. Smith, 1, 360, and
trans, from later German ed. T. & T. Clark, 1880, 3 vols., Vol. 2, pp. 73 *q.
Augustine believed that infants because of hereditary depravity — original
sin — belonged to the " massa perditionis," and, unless relieved from the pen
alty therein inhering by the sacrament of baptism, which was thus a means of
salvation to the infant, must incur the penalty and be lost. Their condemna
tion, however, since they were guilty of no personal sin, would be the lightest
of all — " in damnatione omnium levissima " (C. Jul. Pelag., V. 44).
For a brief, but most excellent and satisfactory, discussion of the Salvation
of Infants, cf. E. G. Robinson, Christian Theology, § 28, pp. 164-169, Roches
ter, N. Y., Press of E. R. Andrews, 1894. — TR.
CH. xvin] ON HUMAN UNDERSTANDING 595
only at the last moment, all the light of faith and all the warmth
of love necessary to their salvation. Thus it is that the Reform
ers explain with Vedelius the view of Zwingli,1 who had also
expressed the same view upon this point of the salvation of the
virtuous men of Paganism, as the doctors of the Roman church
have done. This doctrine also has nothing in common for that
reason with the particular doctrine of the Pelagians or Semi-
Pelagians, from which we know that Zwingli was far removed.
And since we teach against the Pelagians a supernatural grace
in all those who possess faith (in which the three received
religions agree, excepting perhaps the disciples of Pajon) 2 and
as they allow also either faith or at least similar movements to
infants who receive baptism, it is not very extraordinary to
allow as much at least in the article, of death to persons of good
Avill who have not had the good fortune to be instructed as
usual in Christianity.3 But the part of the wisest is to deter
mine nothing upon points so little known, and to content him
self with the general judgment that God can do nothing which
is not full of goodness and justice : melitis est dabitare de
occultis quam litigare de incertis (Augustine, lib. 8, Genes, ad
lit. c. 5).
1 Ulrich Zwingli, 1484-1531, introduced the Reformation into Switzerland
about the same time that Luther, 1483-1546, introduced it into Germany.
His view on the salvation of the heathen, a consequence of his milder view
of original sin or innate depravity, is found in his Christ. FidH brevis et clara
expositio, Werkr, ed., Schuler u. Schulthess, Ziirich, 1828-1842, 8 vols., Vol.
4, pp. 42-78. In his treatise De Provident! a (i&«U,Vol. 4, pp. 79-144) he
advanced the principle that pagans who have acknowledged the true God
and have led a good life, such as Socrates and Seneca, are capable of being
saved without faith ; and he extended this principle to all who have no
knowledge of the gospel. — TR.
2 Claude Pajon, 1626-1685, a French Protestant theologian, Professor of
Theology at Saumer, 1666, and later pastor at Orleans. Pajon taught that
in conversion the Holy Spirit did not act immediately or irresistibly upon the
heart, but that the soul was itself active in the work of salvation, allowing
itself to l>e convinced by the efficacious word of truth found in Scripture with
which the Spirit's influence was intimately united. His views were opposed
by both Lutherans and Reformed. For further account of him, cf. Alex.
Schweizer, Central-Dogmen d. Reform. Kirche, 2 vols., 1854-1856, Vol. 2, pp.
564-663, and in Herzog, Realencyclop. 2d ed., Leipzig, 1883, Vol. 11, pp. 161-
163: W. Gass, Gesch. d.prot. Doymatik, 2, 359 .97.— TR.
3 Cf. Feller, Otium Hanoveranum, No. LXXXVIII., pp. 181-183 (Dutens, 6,
311, 312). — TR.
LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
CHAPTER XIX
OF ENTHUSIASM
§ 1. Ph. [Would to God that all theologians and St. Augus
tine himself had always practised the maxim expressed in
this passage.] But men think that the dogmatic spirit is an
indication of their zeal for the truth, while it is wholty the
contrary. We love the truth in reality only in proportion as
we love to examine the proofs which make it what it is. And
when we judge hastily we are always pressed by less sincere
motives. § 2. The spirit of authority is not one of the less
common motives, and a certain satisfaction it has in its own
reveries is another motive which causes enthusiasm to spring
up. § 3. This is the name which is given to the failing of
those who believe an immediate revelation when it is not
grounded in reason. § 4. And as we may say that reason is a
natural revelation of which God is the author, just as he is
the author of nature, we may also say that revelation is a super
natural reason, i.e. a reason extended upon the basis of new
discoveries emanating directly from God. But these discov
eries suppose that we have the means of discerning them,
which is reason itself; and to desire to proscribe reason in
order to make way for revelation would be to pluck out the
eyes the better to see the satellites of Jupiter through a tele
scope. § T>. The source of enthusiasm is that an immediate
revelation is more convenient and shorter than the long and
difficult process of reasoning which is not always followed by
a happy result. Men have been seen in all ages whose melan
choly mingled with devotion, united with the good opinion
they have had of themselves, has made them believe that they
had an altogether different intercourse with God from other
men. They suppose IIP has promised it to them and believe
themselves his people preferably to others. § 0. Their fancy
becomes an illumination and a divine authority, and their
plans are an infallible direction from heaven, which they are
obliged to follow. § 7. This view has produced great results
and caused great evils, for a man acts more vigorously when
CH. xix] ON HUMAN UNDERSTANDING 597
he follows his own impulses and when the opinion of a divine
authority is sustained by his inclinations. § 8. It is difficult
to draw him therefrom, because this pretended certainty with
out proof flatters his vanity and love for that which is extraor
dinary. Fanatics compare their opinions to sight and feeling.
They see the divine light as we see that of the sun at noon
without needing the twilight of their reason to show it to them.
§ 9. They are certain because they are certain, and their per
suasion is right because it is strong, for this is the result to
which their figurative language reduces itself. § 10. But as
there are two perceptions, that of the proposition and that of
the revelation, we may ask them where is clearness. If it is
in the sight of the proposition, what good is revelation ? It
must then be in the feeling of revelation. But how can they
see that it is God who reveals and not a will-of-the-wisp which
leads them around this circle : this is a revelation because I
believe it strongly, and I believe it because it is a revelation.
§ 11. Is there anything more suited to throw one into error
than to take the imagination for a guide ? § 12. St. Paul had
great zeal when he persecuted the Christians and did not allow
himself to be mistaken. We know that the devil has had
martyrs, and if it is sufficient to be well persuaded we shall not
be able to distinguish the delusions of Satan from the inspira
tions of the Holy Spirit. § 14. It is then the reason which
makes known the truth of revelation. § 15. And if our
belief proved it, it would be the circle of which I just spoke.
The holy men who received the revelations of God had external
signs which persuaded them of the truth of the inner light.
Moses saw a bush which burned without being consumed, and
heard a voice from the midst of the bush, and God, in order to
give him more assurance concerning his mission when he sent
him to Egypt to deliver his brethren, made use of the miracle
of the rod changed into a serpent. Gideon was sent by an
angel to deliver the people of Israel from the yoke of the Mid-
ianites ; yet he demanded a sign in order to be convinced that
this commission was given him on the part of God. § 10. I
do not, however, deny that God sometimes illumines the minds
of men, in order to make them understand certain important
truths or to lead them to good acts, by the immediate influence
and assistance of the Holy Spirit without any extraordinary
598 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
sign accompanying this influence. But in these cases also we
have reason and Scripture, two infallible rules for judging of
these illuminations ; for if they agree with these rules we run
at least no risk in regarding them as inspired of God, although
it is not perhaps an immediate revelation.
Th. Enthusiasm was at the beginning a good term. And as
the sophism properly indicates an exercise of wisdom, enthusi
asm signifies that there is a divinity in us. Eat Dens in nobis.1
Socrates maintained that a god or daemon 2 gave him internal
warnings, so that enthusiasm would be a divine instinct. But
men having consecrated their passions, fancies, dreams, and
even their anger as something divine, enthusiasm began to sig
nify a mental disturbance attributed to the influence of some
divinity, which is supposed to be in those who are smitten there
with ; for the soothsayers, male and female, showed a mental
derangement, when their god seized them, as the Cuintt-an
Sibyl in Vergil.3 Since then we attribute it to those who be
lieve without foundation that their movements come from God.
Nisus in the same poet thinking himself pressed by I know
not what impulse to a dangerous enterprise, in which he per
ished with his friend, proposed it to him in these terms full of
a reasonable doubt : —
Di ne hunc ardorem mentibus addunt,
Euryale, an sua cuique Deus fit dira cupido ? 4
1 Ovid, Fasti, 6, 5 : " Est Deus in nobis, agitante calescimus illo." — TR.
2 On the daemon of Socrates, cf. Zeller, Philos. d. Griech., II., 1 [Vol. 3],
73-91, 4th ed., Leipzig, 1889; J. S. Blaekie, Four Phas-s of Morals, pp. 125-
127, New York. 1872; H. Jackson, "On the Sai^omov of Socrates'" in the
"Journal of Philology," V., and article " Socrates," Encyclop. Brit., 9th ed.,
Vol. 22, p. 246 (Amer. reprint). — TR.
3 Cf. Vergil, dSneid, 6, 49: " Et rabie fera corda tnment." The view here
mentioned by Leibnitz, that persons gifted with inspiration or enthusiasm
were also affected with some derangement or disturbance of the ordinary men
tal processes, was current in one form or another throughout all antiquity,
and had its influence, through the contact of Greek thought with Chris
tianity, in shaping the Christian doctrine of inspiration. Cf. Plato, Phserlrvs,
244, Jowett's trans., 2d ed., 1875, 2, 121, 3d ed., 1892. 1, 449-450; Ion, 533-534,
Jowett, 2d ed., 1, 247-248, 3d ed., 1, 501-503; Timseus, 71-72, Jowett, 2d ed., 3,
654-656, 3d ed., 3, 492-494; the Stoic view, Zeller, Philos. d. Griech., III., 1
[Vol. 5], 336 sq., Plutarch, ibid., III., 2 [Vol. 6], 193 sq. , Philo, 414 *q., Plo-
tinus, 611 sq. ; Prleiderer, R°ligionsphilosophie, 2d ed., 1884,2, 339 sq., Eng.
trans., 4, 46 sq. — TR.
* Verg. Aen. 9, 184-185. — TR.
CH. xix] ON HUMAN UNDERSTANDING 599
He ceased not to follow this instinct although, he knew not
whether it came from God or from an unfortunate desire to
distinguish himself. But if he had been successful, he would
not have failed to acquire authority in another case and to
think himself impelled by some divine power. The enthusi
asts of the present think that they receive also from God the
dogmas which they observe. The Quakers belong to this per
suasion, and Barclay, their first systematic author, maintains
that they find in themselves a certain light which is made
known by itself.1 But why call that light which reveals noth
ing ? I know that there are some persons of this disposition
of mind who see sparks and even something more luminous,
but this image of material light excited when their minds are
aroused gives no light to the mind. Some idiots with a restless
imagination form conceptions which they had not before ; they
are in a condition to say fine or at least very animated things
in their opinion ; they admire themselves and make others
admire this fertility which passes for inspiration. This ad
vantage comes to them largely from a vivid imagination which
passion rouses and from an excellent memory which has well
retained the methods of speech of the prophetic books which
the reading or discourse of others has rendered familiar to
them. Antoinette de Bourignon made use of the facility she
had in speaking and writing as a proof of her divine mission.2
I know a visionary who based his divine mission upon the tal-
1 Cf. Leibnitz's letter to Thos. Burnett, July 17-27, 1696; Gerhardt, Leibniz,
philos. Schrift., 3, 184. On the doctrine of the " inner light," the immediate
revelation of the Spirit of God in each individual soul, " the light that lighten-
eth every man," — the most characteristic doctrine of the Quakers, — cf. Robert
Barclay, 1648-1690, An Apology for the True Christian Divinity, Prop. II.,
Of Immediate Revelation ; and the excellent account of Bancroft, Hist, of the
U. S., chap. 23, Vol. 2, pp. 78 sq., Centenary ed., Boston, 1876. — TR.
2 Antoinette Bourignon, 1616-1680, an enthusiast whose religious doctrines
made considerable stir in her lifetime and for a short time after in Holland
and Scotland, but have long ceased to have any influence and are now almost
wholly forgotten. Her complete works in French appeared at Amsterdam,
1686, 19 vols., 8vo ; 1717, 21 vols., 8vo, with a life of the author by Pierre Poiret,
1646-1719, a Calvinistic minister and famous mystic, who became her disciple,
edited her works, and attempted to reduce to system her vague reveries in his
(Economic de la nature, Amsterdam, 1686, 21 vols., 8vo. Her prophetic views
were expounded in her Traite de Vaveuylement des homines (CEuvres, ed.
1686, Vol. 15), her La lumiere du monde (ibid., Vol. 7), and her De la htmiere
nee en tenebres (ibid., Vol. 4), the last work being "a collection of letters,
with a large explanation of Matt. 24 and 25 " ; Eng. trans. The Light of the
600 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
ents he had in speaking and praying aloud almost an entire
day without ceasing and without becoming exhausted. There
are some persons who, after having practised austerities or
after a state of sadness, taste a peace and consolation in the
soul which enraptures them, and they find therein so much de
light that they believe it to be an effect of the Holy Spirit. It
is true that the contentment they find in considering the great
ness and goodness of God, in the accomplishment of his will,
in the practice of the virtues, is a grace of God and one of the
greatest ; but it is not always a grace which needs a new super
natural aid, as many of these good people maintain. Xot long
since there was a young lady very wise in everything else, who
believed from her youth that she spoke with Jesus Christ and
was his wife in a wholly peculiar manner. Her mother, to
whom this was related, was a little given to enthusiasm, but
the daughter having commenced early had gone very much
farther. Her satisfaction and joy was unspeakable, her wis
dom appeared in her conduct, and her intelligence in her
discourse. The thing went, however, so far that she received
letters addressed to our Lord and she sent them back sealed
as she received them with a reply which sometimes appeared
appropriate and always reasonable. But finally she ceased to
receive them from fear of making too much disturbance. In
Spain she would have been another St. Theresa. But all per
sons who have similar visions do not conduct themselves in
the same way. There are some who seek to form a sect, and
even to make trouble : and England furnishes a strange proof
of this.1 When these persons act in good faith it is difficult to
World, London, 1(596; The Light risen in Darkness, London, 1703. Leibnitz
refers to her in a fragment, $nr V esprit Sectaire, 1697, cf. Dutens, 1, 740. For
further account, cf. J. C. Adelung, Gesch. d. inensch. NarrJieit, Leipzig, 1785-
1789, 7 vols., 16mo', Vol. 5, pp. 245-391 ; Gottfried Arnold, Kirchen u. Ketzerhis-
tori», Frankfort-on-1 he-Main, 1729, Theil. III., Cap. XVI., Vol. 2, pp. 153-176,
Th. IV., Sect. III., Num. XVII.. Vol. 2, pp. 1065-1089; Wetzer u. Welte,
Kirchcnlexicon, Vol. 2, pp. 1167-1170, ed. 1883. — TR.
1 Leibnitz here refers to the Independents, who, arising in obscurity in Eng
land in the reign of Elizabeth and gradually gaining in numbers and influence
as a result of the persecution to which they were subject at the hands of the
established Church and the State, and of their success in founding the New
England States, came to the front in the time of the Revolution and changed
at length the political as well as the religious life of England, and became
a powerful and controlling force in the life and institutions of the American
people. In their fundamental principle that religion is a matter of the jndi-
CH. xix] ON HUMAN UNDERSTANDING 601
reform them : sometimes the overthrow of all their plans cor
rects them, but often it is too late. There was a visionary who
lately died who believed himself immortal because he was very
old and very well, and without having read the book of an
Englishman lately published (who wished to make us believe
that Jesus Christ came to exempt true believers from bodily
death) was almost of the same opinion for some years past;
but when he perceived that he was dying he went so far as to
doubt all religion because it did not correspond to his chimera.
Quirin Kulman [swr],1 a Silesian, a man of knowledge and judg
ment, but who had since indulged in two kinds of visions,
equally dangerous, the one of the enthusiasts, the other of the
alchemists, and who made some stir in England, Holland, and
even in Constantinople, being at last advised to go into Russia
and there to mix himself up in certain intrigues against the
minister, at the time when the Princess Sophia governed it,
was condemned to be burned, and did not die like a man per-
vidual reason and conscience, wholly free from State or other control, they
bore in a general way a somewhat close resemblance to the Quakers and
other enthusiasts of their time.
In this connection Schaarschmidt ventures the conjecture that Leibnitz
may have had his attention called to the persons and circumstances men
tioned in this chapter by a large work, appearing not long before, entitled,
Anab'iptixticum et enfi usiasticum Pantheon, und Geistliches Eiisthanss wider
die Alten Quacker und Neuen Frey-Geister. u. s. w., Cothen, W. A. Meyer,
170'.?, since his allegations strikingly call to mind this work. But may not
Bayle's Dictiomiairs as well have been the source of his information, inas
much as it contains considerably extended articles on the persons mentioned,
and was a work with which Leibnitz Was thoroughly familiar? — TR.
1 Quirin Kulilmann, 1(551-1689, in consequence of a disordered brain result
ing from a severe illness at the age of 18, became subject to hallucinations,
lost his previous taste for study, claimed to possess a method by which he
might know everything independent of the usual processes of acquisition, and
that the Holy Ghost was bis only teacher, and on these grounds considered
himself a saint. At Leyden, falling in with the works of Boehme, he imme
diately became an enthusiasti',- dis-inle. It is said that he wished to marry
Antoinette Bouriguon, but that her " inviolable chastity " caused her to refuse
him. Leaving Holland in 1(575 he travelled, it is believed, in England, France,
and Turkey. At Constantinople he addressed a letter. Aug. 1, 1(578, to the
Sultan Mahomet IV., in which he predicted the conversion of the Turks, and
sought to win the Sultan to his views. Failing to attain his desired end, he
went to Russia to set up the true kingdom of God, was opposed by Peter the
Great, and after a brief trial condemned by the Greek Patriarch — it is said
at the suggestion of a Lutheran clergyman — to be burned alive as a heretic
in 1(589. For further .account, cf. Adelung, Gc.sch. d. ine.nsch. Narrhe.it, Vol.
5, pp. 3-90 (allusion to his alchemistic impostures, ibid., pp. 52, 53, 65, 81) ;
Wetzerund Welte, Kirchenlexicon, 7, 1237. — TR.
602 LEIBNITZ'S CRITIQUE OF LOCKE [UK. iv
suaclecl of that which he had preached. The dissensions of these
people among themselves ought further to convince them that
their pretended internal witness is not divine ; and that other
signs are necessary to justify it. The Labadists,1 for exam
ple, do not agree with Mademoiselle Antoinette, and although
William. Penn appears to have had the design in his travels in
Germany, of which he has published an account, of establish
ing a kind of understanding between those who rely upon this
witness, lie does not appear to have succeeded.2 It is desira
ble for the truth's sake that good people be intelligent and
act in concert : nothing would be more capable of rendering
the human race better and happier, but it would be necessary
for them to be truly of the number of the good people, i.e.
of the beneficent, and, further, docile and reasonable ; instead
1 The Labadists were a mystic sect or community of the Reformed Church
founded by Jean de Labadie, 1610-1(574, a noted Pietist or Mystic, who, origi
nally a Roman Catholic, had become a Protestant, joined the Reformed Church,
and afterwards at the head of his separatist congregation at Middleburg
developed his scheme for the reformation of that ecclesiastical body. His
doctrine was in many points similar to that of the Anabaptists. Labadie
and his disciples wished to settle with A. Bourignon at Noordstrandt, but she
would not consent, saying: '; I perceive and know that we can never agree
together. Their opinions and the spirit that governs them are altogether con
trary to my light and the spirit that governs me." Leibnitz refers to Labadie
in the Theodicee, Discours prelim., § 14; in a letter to Theophilus Spizel,
April 7, 1671, Dutens, 5, 351-352 ; cf. also, Guhrauer, Leibnitz's dentsche
Schrift., 2, 498-499. For further account, cf. the writings of two of his most
enthusiastic disciples, Pierre Yvon, Abrege precis de la vie et de la conduite
et des vrais sentiments de feu M. de Labadie; Anna Maria v. Schiirman,
Eucler/a (said to be, perhaps, the best exposition of his views), Altona, 1673,
1678: also Arnold, Kirchen und Ketzerhistorie, Theil. II., Biu-.h. XVII., Cap.
XXI , Vol. 1, pp. 118(5-1200 ; Vol. 2, pp. 1302-1350 : H. van Berkum, De Labadie
en de Labadisten, Sneek, 1851; Goebel, Gesch. d. christ. Lebens in d. rhein-
isch-ivestphalischen Kirche, Vol. 2, Coblentz, 1852; Heppe, Gesch. d. Pietis-
mus, Leyden, 1870; Ritsche, Gesch. d. Pietismns, Vol. 1, Bonn, 1880. — TR.
2 William Penn, 1644-1718, made a missionary journey through Holland
and Germany in 1671-1672, in the course of which he founded a Quaker society
at Embden and became an intimate friend of the Princess Elizabeth of the
Palatinate, to whom Descartes dedicated his Princip. Philos. His letters
written during this journey contain a full account of the doctrine of the
"inward light." In 1677 he made another missionary journey to the Conti
nent, and published in 1694 a full account of the same, entitled Journal of my
Travels in Holland and Germany. Cf. A Collection of the Works of Wm.
Penn, London, 2 vols., fol., 1726, Vol. 1, pp. 50-116; Select Works, 3d ed., Lon
don, 1782. 5 vols., 8vo, Vol. 3, pp. 373 sq. For short selections therefrom, cf.
Janney, Life of Wm. Penn, chap. 9, pp. 125-137, 4th ed. revised, Phila., 1878;
for more extended extracts, cf. Passages from the Life and Writings of Wm.
Penn, Phila., 1882, VIII., pp. 141-199.— TR.
CH. xix] ON HUMAN UNDERSTANDING 603
of which only too many of those who are called devout to-day
are accused of being severe, imperious, obstinate. Their dis
sensions make it appear at least that their internal witness
needs an external verification in order to be believed, and mir
acles would be necessary in order for them to have the right
to pass as prophets and inspired men. There, might, however,
be a case where these inspirations would carry their proofs
with them. This would be if they really enlightened the mind
by important discoveries of some extraordinary knowledge,
which without any external aid would be beyond the powers
of the person who should have acquired them. If Jacob
Boehme,1 a famous shoemaker of Lusace, whose writings have
been translated from German into other languages under the
name of the Teutonic Philosopher, and in reality possess some
thing of grandeur and beauty for a man in this condition, had
known how to make gold, as some are persuaded he did, ov as
St. John the evangelist did, if we believe what is said in a
hymn - composed in his honor : —
Inexhaustum fert thesaurum
Qui de virgis fecit aurum,
Gemmas de lapidibus,
there would have been some reason for giving more credence
to this extraordinary shoemaker. And if Mademoiselle Antoi
nette Bourignon had furnished to Bertrand la Coste, a French
engineer at Hamburg, the light in the sciences which he believed
he had received from her, as he indicated in dedicating to her
his book 011 the Quadrature of the Circle (in which, making
allusion to Antoinette and Bertrand, he called her the A in
theology, as he said he himself was the B in mathematics), we
should not have known what to say.3 But we do not see exaiii-
1 C'f. «nte, p. 298, note 1. — TR.
2 Cf. L. Gautier, (Euvres Poetiques d'Adam de S.-Victor, Paris, 1858, 2
vols., 12iuo, Vol. 1, p. 220, and the editor's learned note; D. S. Wrangham,
The Liturgical Poetry of Adam of St. Victor, from the text of Gautier, with
trans.- into English in the original metres, etc., 3 vols., London, Kegan
Paul, 1*81, Vol. 1, p. liiO. Leibnitz probably knew the hymn in Cliehtoveus,
Elucidatorium Ecclesiasticum, Pt. IV., of which there were several editions
from 151.V1556, at Paris, Basel, Geneva. — TR.
3 Bertrand de Lacoste, a French engineer, born early in the 17th century,
who, after some service as colonel of artillery in the army of the Duke of
Brandenburg, obtained his discharge in 1(>63 and retired to Hamburg, where
he devoted himself to the study of mathematics in general, and in particular
604 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
pies of a considerable success of this nature, nor well-detailed
predictions which have succeeded in the case of such persons.
The prophecies of Poniatovia,1 of Drabitius and others, which
the good man Comenius 2 published in his " Lux in Tenebris,"
and which contributed to the disturbances in the hereditary
lands of the emperor, were found false, and those who believed
them were unfortunate. Kagozky, Prince of Transylvania, was
impelled by Drabitius ;? to the attack upon Poland in which he
to the problem of the quadrature of the circle. On this subject he published
two works: Scheda de inventa quadratura circii1!, 1063, and, in reply to a
refutation of the same by Prof. Miiller, Demonstration de la quadrature du
cercle, Hamburg, 1666, 4to, 1677, 8vo. A Flemish translation appeared in
1G77, with the title Klarer l>ewys von't Quadrat des Cirkeis, dedicated to
Antoinette Bourignon, whose person and teachings he for a time greatly
admired ; but failing to interest her equally in his mathematical studies, he
finally opposed her and her doctrines as strongly as he had before advocated
them, exciting the populace of Hamburg against her and forcing her to
leave the city. He wrote against her his Scheda contra Ant. Bourignoniam.
— TR.
1 Christine Poniatowa, 1610-1644, a famous enthusiast, the daughter of a
Polish noble and unfrocked monk, claimed in 1627-1628 that she had visions
regarding the persecutions of the Evangelical Church which were soon to end
in its triumph. Jan. 27, 1629, she fell into a lethargy so profound that they
thought her dead: but at length awaking, she declared that her visions were
ended, her mission complete. Chagrin at seeing her predictions denied at
last caused her death. She wrote out her revelations in the order in winch
she said she had received them from heaven. Comenius (rf. ant", p. 40(5,
note 2) translated them into Latin, and published them, together with those
of Drabitius, Kotter, l.">xr>-l'>-'7, and other enthusiasts, in his very rare Li'?,
in TeiH'hrix. 1^50. l''57,4to, 16~)0, with title Hlx'oriri rerrlatiotn/.m ('h. Kotten,
("ir. Poni'itovise, Ni<-. Drabitii, etc. (the only ed. known to Bayle, and the
least rare and complete), 1665, 2 vols., 4to, also several other eds.. more or
less incomplete. The rarity of the work is due to the fact that Comenius,
fearing on the one hand to disobey a divine command if he refused to trans
late these prophecies out of the Bohemian or C/ech language in which they
had first appeared, and on the other of covering hims-lT with ridicule if the
event not far dis'ant did not verify them, allowed but few copies to be printed.
For further account of Poniatowa, cf. Adelung, G"sch. d. inei/Kch. Narrhcit,
Vol. (J. pp. 2:51-21)7. — TR.
2 (tf. tint", p. 4''6, note 2. The Lny i» T^ndr-i* appeared in 1650. — TR.
3 Nicolas Drabitius or Drabicius, c. 1587-1671, a Bohemian-Moravian min
ister at Drakatutx. who was compelled by the severity of the imperial edicts
against the Protestants to retire to Lednit;: in Hungary, turned to secular
pursuits, became very dissipated, and was suspended from the ministry. In
16^8 he claimed to be inspired and to have divine revelations, the chief of
which predicted the fall of the Hons° of Austria in 1657, and the success of the
expedition, which he urged upon Prince George II. Kakoczy of Transylvania,
against Poland in the same year. Both predictions failed. Prince George
was totallv def'-ated July 16, 16~7, and compelled to fight the Turks, roused
to hostility by his attack on Poland, till his death, June 26, 1660. The House
CH. xix] ON HUMAN UNDERSTANDING 606
lost his army, a result which finally cost him the loss of his
estates together with his life ; and the poor Drabitius a long
time after, at the age of eighty years, at last had his head cut
off by the order of the emperor. Yet I do not doubt that there
are people now who cause these predictions to be revived inaptly
in the present conjuncture of disorders in Hungary, not consid
ering that these pretended prophets spoke of the events of their
time ; in which respect they did almost as he who, after the
bombardment of Brussels, published a loose sheet, in which
there was a passage taken from a book of Mademoiselle Antoi
nette, who did not wish to come into this city because (if I
remember rightly) she had dreamed that she saw it on fire ; but
this bombardment happened a long time after her death. I
knew a man who went to France during the war which was ter
minated by the Peace of Nimwegen to importune M, de Mon-
tausier l and M. de Pomponne 2 upon the trustworthiness of the
prophecies published by Comenius ; and he would himself have
believed himself inspired (I think), if he had happened to make
his propositions in a time parallel to ours. This shows not only
the little foundation, but also the danger of these wayward
nesses. Histories are full of the bad effect of false or misunder
stood prophecies, as may be seen in a learned and judicious
dissertation, " De officio viri boni circa futura contingentia,"
which the late Jacobus Thomasius, a celebrated professor at
Leipzig, formerly gave the public.3 It is true, however, that
of Austria, resolving to rid itself of the pretended prophet, arrested him as
a state criminal, tried and condemned him to death. His head and right
hand were cut off and bnrned with a copy of his books, and the ashes thrown
into the Danube. July 17, 1671. For further account, cf. Adelnng, Gesch. d.
menxch. Nnrrh»H, Vol. 2, pp. 27-(52. — TR.
1 Charles de Sainte-Maure, Marquis and then Duke de Montausier, 1610-1690,
to whom Louis XIV., in 1668, entrusted the education of the Dauphin, then
seven years of age, for whose instruction he edited the Delphine Classics and
a Recmil de mcixinies morales et politiquos. — TR.
2 Simon Arnauld, Marquis de Pomponne or Pompone, 1018-1600, was am
bassador to Sweden under Louis XIV., and concluded the Peace of Ximwegen,
1678-1679. His Memoires de Marquis de Pomponne appeared at Paris, 1861-
1863, 2 vols., 8vo. — TR.
3 Jacob Thomasen, — Latin Thomasius, — 1622-1684, was for many years
Professor of Philosophy and Eloquence in the University of Leipzig, the
founder of the scientific study of the history of philosophy in Germany, and
the first to recommend disputed questions in this subject as themes for dis
sertations. He was Leibnitz's first teacher in philosophy, early discerned
the eminent abilities and promise of his subsequently very distinguished
606 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
these persuasions sometimes produce a good effect and render
great service, for God can make use of error to establish or
maintain truth. But I do not believe that it is easily permitted
us to make use of pious frauds for a good end; and as for the
dogmas of religion, \ve have no need of new revelations ; it is
enough that we propose to ourselves salutary rules in order that
we may be obliged to follow them, although the one proposing
them performs no miracle. And although Jesus Christ was pro
vided with miracles, he did not cease to refuse sometimes to per
form them in order to please that perverse race who demanded
signs, when he preached only virtue and what had already been
taught by natural reason and the prophets.1
pupil, taught him to take a broad and, for that time, critical view of the
history of philosophy, and introduced him early into the polemic against em
piricism. The pupil regarded his teacher with reverent gratitude (cf. Leib
nitz's letters to Thomasius, April 20-30, 16(59, Gerhardt, Leibniz. Philox.
Schrift., 1, 15, 26-27 ; to J. Christ. Wolf, Dec. 11, 1711, Dutens, 5, 447, Kortholt,
Leibn.it. Epist., 1, 270; Leibnit. Vita a Jac. Bruckero scripta, § 3, Dutens,
1, LVIII.-LXL, and Brucker, Philos. Historia, 5, 336-340, Lipsise, 1742-1767),
and each prized the esteem and friendship of the other. Leibnitz sent Tho
masius his own early works for criticism (" Neque vero laudem, sed examen
peto," letter of April 20-30, 1669, G. 1, 27) ; Thomasius presided when Leib
nitz defended his De princ. indiv. for the degree of Bachelor of Philosophy
(rf. ante, p. 239, note 1), and when it was published wrote the Preface (for
which cf. Duteus, 2, Pt. I., 11-14). For their correspondence, the preservation
of Leibnitz's part of which we owe to the care of Thomasius, cf. Gerhardt,
op. cit., 1, 1-39. Most important for the philosophy of Leibnitz, especially as
regards the beginning of his independent speculations, and as a statement of
principles from which he never departed but simply worked out into clearer
and completer forms, is the letter of April 20-30, 1(569, cf. G. 1, 15-27, Erd-
mann, 48-.14, Outers, 4, 7-19, also Guhrauer, Leibniz' Dissert, de princ. indiv. ,
p. 33. Leibnitz refers frequently to Thomasius ; cf. for example, Theodicee,
Pt, II., §§ 184, 220.
The essay of Thomasius here referred to by Leibnitz is also cited, accord
ing to Schaarschmidt, under the title De officio hominis circa notitiam futu-
roj'uin contingonfium, and, in his opinion, is probably the same as the one
which Christian Thomasius, after his father's death, had printed in his Disser-
tationis LXIII. maynain partein ad historiam philosophicam et ecclesiasticaiu
pertin^nteft, Halle, 1093, 8vo, as Programma XXXVI. , p. 396, under the title,
De provisions circa futura contingentia. Thomasius was the author of a
great number of dissertations, full of research and written with purity and
elegance. One of them, Origines historisB philosophies et ecclesiastics^, Leip
zig, 16()5, 4to, ed. by Ch. Thomasius, Halle, 1(599, Svo, was for a long time the
most accurate history of ancient philosophy. Brucker was greatly indebted
to it. — TR.
1 Cf. ante, pp. 553, note 1, 582. Leibnitz, while admitting the possibility
and on sufficient and proper evidence the actuality of miracles, nevertheless
regards them from the philosophic point of view as exceptional and relatively
CH. xx] ON HUMAN UNDERSTANDING 607
CHAPTER XX
OF ERROR
§ 1. Ph. After having spoken of all the means which make
us know or divine the truth, let us also say something about
our errors and bad judgments. Men must often be mistaken
since there are so many dissensions among them. The reasons
of this may be reduced to these four : (1) the lack of proofs ;
(2) little skill in using them ; (3) lack of will to make use of
them ; (4) false rules of probability. § 2. When I speak of the
lack of proofs, I understand also those which we might find if
we had the means and the opportunity, but this it is which we
most frequently lack. Such is the condition of men whose
life is passed in seeking their subsistence : they are as little
informed of what goes on in the world, as a draught horse who
always goes by the same road may become skilled in the map
of the country. They would require languages, reading, con
versation, observations of nature and the experiments of art.
§ .'>. Now, all this not agreeing with their condition, shall we
say then that the bulk of men are led to happiness or misery
only by blind chance ? Must they abandon themselves to the
current opinions and authorized guides in the country, even as
regards eternal happiness or misery ? Or will they be eternally
unhappy to have been born rather in one country than in
another ? We must admit, however, that no one is so com
pletely occupied with the care of providing for his subsistence
as to have no time left to think of his soul and to be instructed
in that which concerns religion, if he were to apply himself
thereto as he does to less important things.
Th. Suppose that men are not always in a condition to
instruct themselves, and that not being able to give up with
unimportant, and emphasizes, as here, the view that the essence of Christianity
consists in its ethical content, a content intrinsically rational and accordant
with nature. In addition to the authors referred to, ante, p. 553, note 1, cf.
Piinjer, Gesch. d. christ. Peligionsphilos., 1, .">5!)-3(>0, 372-375, En#. trans.,
480-515, espec. 485-486, 501-504; and for an .acute and ahle discussion of
Miracles, their idea, office, etc., cf, E. G. Robinson, Christian Theology, § 20,
pp. 103-109, Rochester, N. Y., Press of E. R. Andrews, 1894. — TR.
608 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
prudence the care of the subsistence of their family in order
to investigate difficult truths, they are obliged to follow the
opinions authorized among them, it will always be necessary
to judge that in the case of those who have the true religion
without having its proofs, internal grace will supply the lack
of the motives of credibility, and charity makes us also judge,
as I have already indicated to you, that God does for persons
of good will, brought up among the thick darkness of the most
dangerous errors, all that his goodness and justice demand,
although perhaps in a way which is unknown to us. We have
histories commended in the lioman church of persons who have
been expressly raised up in order that salutary aid be not want
ing. But God can assist souls by the internal operation of
the Holy Spirit, without the need of so great a miracle ; and
because it is good and consoling for the human race to put itself
in the condition of the grace of God, only the good but sincere
and serious will is needed. I admit that we have not indeed
this good will without the grace of God, forasmuch as all
natural or supernatural good comes from him ; but it is always
enough that we must only have the will, and that it is impos
sible that God can demand a condition easier and more reason
able. .
§ 4. Ph. There are those who are sufficiently at their ease to
have all the opportunities suited to illumine their doubts ; but
they are deterred from this by obstacles full of craftiness, which
it is easy enough to see, while it is not necessary to display them
in this place. § 5. I prefer to speak of those who lack the skill
to avail themselves of the proofs which they have, so to speak,
under their hand, and who cannot retain a long course of argu
ment nor weigh all the circumstances. There are some people
of a single syllogism, and there are some of two only. This is
not the place to determine whether this imperfection arises from
a natural difference of the souls themselves or of the organs, or
whether it depends upon the lack of exercise which polishes the
natural faculties. It is sufficient for us here that it is visible,
and that we have only to go from the palace or from the
exchange to the hospitals and small houses to perceive it.
Tli. It is not the poor alone who are needy; certain rich
people lack more than they, because these rich people demand
too much and put themselves voluntarily in a kind of poverty
en. xx] OX HUMAN UNDERSTANDING 609
which hinders them from applying themselves to important con
siderations. Example does much here. One tries to conform
to that of his equals, so that he is compelled to practise without
showing a spirit of perverseness, and that makes it easy for him
to become like them. It is very difficult to satisfy at the same
time reason and custom. As for those who lack capacity, they
are fewer perhaps in number than you think ; I think that
good sense with application can suffice for everything which
does not demand promptness. I presuppose good sense, be
cause I do not think you would demand the search for truth
from the dwellers in small houses. It is true that there are
not many who could not learn something of it, if we knew the
means of so doing and what original difference exists between
our souls (as I believe does in reality exist) ; it is always cer
tain that one soul might go as far as another (but not perhaps
so rapidly) if it were led as it should be.
§ 6. Ph. There is another sort of people who lack only will.
A strong attachment to pleasure, a constant application to what
concerns their fortune, a general idleness or negligence, a par
ticular aversion to study and meditation, prevents them from
thinking seriously of the truth. There are even some who
fear that a research free from all partiality would not be fa
vorable to the opinions which most suit their prejudices and
plans. We know persons who will not read a letter which
they suppose brings bad news, and many people avoid agreeing
upon their accounts or informing themselves of the state of
their property, for fear of learning what they would desire
always to be ignorant of. There are some who have large rev
enues and employ them all in provisions for the body without
dreaming of the means of perfecting the understanding. They
take great care always to appear in a suitable and brilliant
equipage, and they suffer without difficulty their soul to be
covered with the wretched rags of prejudice and error, and its
nakedness, i.e. its ignorance to appear as an eccentricity. Xot
to speak of the interest they ought to take in a future state,
they do not in the least neglect what they are interested to
know in the life they lead in this world. And it is strange
that very often those who regard power and authority as an
appanage of their birth or their fortune, carelessly abandon it to
people of a condition inferior to theirs, but who surpass them
610 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
in knowledge. For it is very necessary that the blind be led
by those who see, lest they fall into the ditch, and there is no
worse slavery than that of the understanding.
Th. There is no more evident proof of the negligence of men
as regards their true interests, than the little care they take to
know and practise what agrees with their health, which is one
of our greatest blessings ; and although the great feel as much
and more than others the bad effects of this negligence, they
do not alter their course. As far as faith is concerned, many
regard the thought which would lead to its discussion as a
temptation of the devil, which they think they can the better
surmount only by turning their minds to an entirely different
thing. Men who only love pleasure, or who are attached to
some occupation, are wont to neglect other matters. A player,
a hunter, a drinker, a debauchee, and even a man curious about
trifles, will lose his fortune and his property for lack of giving
himself the trouble to institute a process or to speak to the
men in a guard-house. There are some like the Emperor
Honoring, who, when the news of the destruction of Koine
was brought to him, thought it was his hen who bore this
name, and this offended him more than the truth.1 It is
desirable that men who have power have knowledge in pro
portion ; but if the details of the sciences, of the arts, of
history and languages, should not be theirs, a solid and prac
tised judgment and a knowledge of things equally great and
general, in a word, summa rerum, might suffice. And as the
Emperor Augustus had an abstract of the forces and needs of
the State which he called Breviarium Imperil', he might have
an abstract of human interests which would deserve to be called
Enchiridion Sapient ire, if men would care for that which is of
most importance to them.
§ 7. Ph. Finally, the majority of our errors arise from the
false measures of probability which we take, whether by sus-
1 The anecdote here mentioned hy Leibnitz is thus given by Giovanni Bat-
tista Egna/io, 1473-1553, in his I)e Romanis principibus, Lib. III., Venice,
151(>, near the end of Book I. (<•/. Haurisius, Scriptures historlsB R >man%
Latini reteres, quse, extant oiHH.es, Heidelberg, 1743-1745, 3 vols., fol., Vol. 3,
p. 025) : " Quum nnntiatnm Honorio esset Ravenna; Roniam pcrditam, cre-
didit ille de pugnaci Gallo, cui nomen erat Romre, signification esse: admira-
tumqne vehementer tarn subito periisse eum quo cnm panllo ante festivissime
Inserat.'' — TR.
CH. xx] ON HUMAN UNDERSTANDING 611
pending our judgment in spite of manifest reasons, or in giving
it notwithstanding contrary probabilities. These false measures
consist (1) in doubtful propositions taken as principles, (2) in
the accepted hypotheses, (3) in the dominant passions or incli
nations, (4) in authority. § 8. We ordinarily judge of truth by
its conformity with what we regard as indisputable principles,
and this makes us despise the testimony of others and indeed
of our own senses when they appear contrary thereto: but
before relying upon these with so much assurance, we should
examine them with the utmost exactness. § 9. Children receive
the propositions taught them by their father and mother, nurses,
teachers and others who are about them, and these propositions
having taken root, are regarded as sacred as a Urim and Thum-
mim which God might himself have put in the soul. § 10.
We have some difficulty in admitting that which clashes with
these internal oracles, while we believe the greatest absurdities
which agree with them. This appears in the extreme obstinacy
which we notice in different men who believe strongly opinions
as directly opposed as the articles of faith, although they are
very often equally absurd. Take a man of good sense, but per
suaded of this maxim that he must believe what they of his
communion believe, as they teach at Wittenberg or in Sweden,
what disposition has he not to receive without difficulty the
doctrine of con substantiation, and to believe that one and the
same thing is flesh and bread at the same time.
Tli. It is very apparent, sir, that you have not been suffi
ciently instructed in the views of the Evangelicals,1 who admit
the real presence of the body of our Lord in the Eucharist,
They have explained a thousand times that they do not mean
the consubstantiation of bread and wine with the flesh and blood
of Jesus Christ, and still less that one and the same thing is
flesh and bread at the same time. They teach only that, in
receiving the visible symbols, we receive in an invisible and
supernatural manner the body of our Saviour, without its being
enclosed in the bread ; and the presence which they mean is
not local or spatial, so to speak, i.e. determined by the dimen
sions of the present body, so that all that the senses can oppose
1 I.e. Lutherans. For the views and controversies regarding the Eucharist,
and the Confessions alluded to in the remainder of this section, cf. the various
Church Histories and Histories of Doctrine. — TR.
612 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
to it does not concern them. And in order to show that the
inconveniences which may be derived from reason no longer
affect them, they declare that what they mean by the substance
of the body does not consist in extension qr dimension ; and
they make no difficulty in admitting that the glorious body of
Jesus Christ preserves a certain ordinary and local presence,
but congruous with his position in the exalted place where he
is found, altogether different from this sacramental presence
herein questioned, or from his miraculous presence by which he
governs the church, which causes him to be not everywhere
like Clod, but there where he prefers to be. This is the view of
the more moderate, so that, in order to show the absurdity of
their doctrine, it would be necessary to show that the entire
essence of the body consists only in extension, and in that
which is solely measured thereby, which no one, so far as I
know, has yet done. This whole difficulty also concerns not
less the Reformers who follow the Galilean and Belgian confes
sions, the declaration of the Council of Sendomir, composed of
people of the two confessions, Augustan and Swiss, conformed
to the Saxon confession, destined for the Council of Trent ; the
profession of faith of the Reformers who came to the Conference
of Thorn, convoked under the authority of Yladislas, King of
Poland, and the constant doctrine of Calvin and of Beza, who have
declared the most distinctly and the most strongly of everybody
that the symbols really furnish what they represent, and that
we become participants in the body and blood of Jesus Christ.
Calvin, after having refuted those who content themselves with
a metaphorical participation of thought or of seal and with a
union of faith, adds that we can say nothing sufficiently strong
to establish its reality, that he is not ready to subscribe to, pro
vided we avoid everything which looks to the circumscription
of place or the diffusion of dimension ; so that it appears that
at bottom his doctrine was that of Melanchthon and even of
Luther (as Calvin himself conjectured in one of his letters),
except that in addition to the condition of the perception of the
symbols with which Luther contents himself, he demands also
the condition of faith, in order to exclude the participation of
the unworthy. I have found Calvin so positive upon this real
communion in a hundred places in his works, and even in his
familiar letters, where there was no need of being so, that I do
not see any reason to suspect artifice.
CH. *x] ON HUMAN UNDERSTANDING 613
§. 11. Ph. [I ask your pardon if I have spoken of these gentle
men according to the common opinion. I remember now hav
ing remarked that some very clever theologians of the Anglican
church have been for this real participation. But from estab
lished principles let us pass to the accepted hypotheses. Those
who admit that they are only hypotheses often cease not to
maintain them with warmth, almost as if assured principles,
and to despise contrary probabilities. It would be unendurable
to a learned professor to see his authority overturned in an
instant by a new comer who should reject his hypotheses; his
authority, I say, which has been in vogue for thirty or forty
years, acquired by much labor at night, sustained by much
Greek and Latin, confirmed by a general tradition and by a
venerable beard. All the arguments which we can employ to
convince him of the falsity of his hypothesis will be as little
capable of prevailing upon his mind as the efforts Boreas made
to compel the traveller to leave his cloak, which he held so
much the more firmly as the wind blew with more violence.
Th. In reality the Copernicans have experienced in the case
of their adversaries that hypotheses recognized as such cea.sed
not to be maintained with an ardent zeal ; and the Cartesians
are not less positive regarding their grooved particles and little
balls of the second element l than if they were the theorems of
Euclid; and it seems that zeal for our 'hypotheses is merely a
result of the passion we have of making ourselves respected.
It is true that those who condemned Galileo believed that the
rest of the earth was more than an hypothesis, for they judged
it in conformity with Scripture and reason. But since then it
has been perceived that reason at least sustained it no longer ;
and as for Scripture, Father Fabry, Penitentiary of St. Peter,
an excellent theologian and philosopher, publishing in Rome
itself an Apology for the Observations of Eustachio Divini,2
1 Of. Neiv Essays, Preface, ante, p. 51, line 11 ; Descartes, PrincAp. Philos.,
Pt. III., §§ 52, 90. The "grooved particles" and "little balls of the second
element" are a part of the vortices-theory (cf. ante, p. 552, note 1). For the
"matter of the first and second element" and the genesis of the "perfect
globes " or " balls of the second element," cf. Princip. Philos., Pt. III., § 48 sq.
The notes of ..I. H. von Kirchmann in his German trans, of this work of Des
cartes (Philos. Bibliothek., Vol. 26, 2d ed., Heidelberg, 1887) are a valuable
aid in the study of the theory. — TR.
2 Eustachio Divini, c. 1620 — c. 1666, an Italian mechanician, optician, and
astronomer, noted for his skill in making optical instruments, especially tel-
OH LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
a famous optician, hesitated not to declare that it was only pro
visionally that they understood in the sacred text a true move
ment of the sun, and that if the view of Copernicus were found
true, there would be no difficulty in explaining it in like man
ner as this passage of Vergil :
> temeque urbesque recedunt.1
However, they did not cease to continue in Italy and in Spain
and even in the hereditary states of the emperor to suppress
the doctrine of Copernicus, to the great detriment of these na
tions whose scholars might have raised themselves to more
beautiful discoveries had they enjoyed a reasonable and philo
sophic liberty.
§ 12. Ph. The dominant passions appear to be in reality, as
you say, the source of the love we have for hypotheses : but
they also extend very much farther. The greatest probability
in the world will avail nothing in showing his injustice to an
avaricious and ambitious man; and a lover will have every
facility in the world for allowing himself to be duped by his
mistress, so long as it is true that we easily believe whatever
we wish, and according to the remark of Vergil,
qui amant ipsi sibi somnia finguut.2
This is what makes them make use of two means of escaping
the most apparent probabilities when they attack our passions
and our prejudices. § 13. The first is to think that there may
be some sophistry concealed in the argument which they oppose
to us. § 14. The second in supposing that we might put before
hand wholly as good or even better arguments in order to beat
the adversary, if we had the opportunity, or skill, or aid, which
escopes, was the reputed author of a little work entitled Brevis annotatio in
Si/fftenia Suturninni Christiani Iluf/adi [Hag. Com., 1659, 4to], Rome, 1660,
8vo, in which an attempt was made to refute Huygens' theory of the planet
Saturn. Divini, however, was no Latinist, and prohahly had little share in
the hook, contributing merely " his pretended observation of the three sepa
rate bodies"; the real author was most likely the Jesuit, Honore Fabri ('/.
ante, p. 586, note 2). Huygens reprinted the work together with his reply,
Brevis axsrjrtio systematis Saturnii sui, Hag. Com., 1(500; and Divini pub
lished his rejoinder, Septempedanus pro sua annotations in syst. Saturn. (Jh.
Huqenii, adversum ejus assertionem, Rome, 1661. On the whole subject, cf.
Huygens, (Euvres completes, La Haye, 1888-1893, 5 vols., passim. — TR.
1 JE/i. 3, 72. — TR.
2 Ecloff. 8, 108. — TR.
CH. xx] ON HUMAN UNDERSTANDING 615
we must have to discover them. § 15. These means of shield
ing themselves from conviction are sometimes good, but they
are also sophisms when the matter is sufficiently explained and
everything has been taken into account; for after that there
are means of knowing with regard to all upon what side the
probability is found. Thus there is no room for doubting that
the animals have been formed by the movements of an intelli
gent agent, rather than by a fortuitous concourse of atoms ; as
there is no one who doubts in the least whether the characters
of printing which form an intelligent discourse have been
brought together by an attentive man, or by a confused medley.
I should think then that it does not depend upon us to suspend
our assent in these instances ; but we can give it when the
probability is less evident, and we can even content ourselves
with more feeble proofs which better agree with our inclina
tion. § 16. It appears to me impracticable for the truth for a
man to lean to the side upon which he sees the less probability ;
perception, knowledge and assent are not arbitrary, as it does
not depend upon me to see or not to see the agreement of two
ideas, when my spirit is turned toward them. We can how
ever voluntarily arrest the progress of our researches ; without
this ignorance or error could not in any case be a sin. It is in
this that we exercise our liberty. It is true that in the in
stances where we have no interests, we embrace the common
opinion, or the view of the first comer ; but in the points where
our happiness or misery is concerned, the mind applies itself
more seriously to weighing the probabilities, and I think that
in this case, that is, when we are attentive, we have no choice
in determining ourselves for the side we prefer, if between the
two sides there are differences at once visible, and that it will
be the greatest probability that will determine our assent.
Th. 1 am of your opinion at bottom, and we have given
sufficient explanation upon this matter in our preceding con
ferences when we spoke of liberty. I showed then that we
never believe what we wish, but rather what we see is the most
apparent ; and that nevertheless we can make ourselves believe
indirectly what we wish by turning away the attention from a
disagreeable object in order to apply ourselves to another which
pleases us. This makes us in regarding more the reasons of
a favorite side believe at last the more probable. As for the
616 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
opinions in which we take little interest and which we receive
upon slight reasons, we do this because, noticing scarcely any
thing which opposes them, we hud that the opinion which
makes us regard them favorably surpasses as much or more
the opposite opinion, which has nothing in its behalf in our
perception, as if it had had many reasons on both sides, for the
difference between 0 and 1, or between 2 and 3, is as great as
between 9 and 10, and we perceive this advantage, without
thinking of the examination which would still be necessary
in order to judge, but to which nothing impels us.
§ 17. Ph. The last false measure of probability that I in
tended to notice is improperly understood authority, which keeps
more people in ignorance and error than all the others together.
How many people we see who have no other basis for their
views than the opinions received among our friends or among
the members of our profession or of our party, or of our coun
try ! Such a doctrine has been approved by venerable antiq
uity ; it comes to me under the passport of preceding centuries ;
other men yield to it ; this is why I am shielded from error in
receiving it. We have as much authority for tossing up in
order to take these opinions, as to take them upon the basis of
such rules. And besides the fact that all men are liable to
error, I believe that if we could see the secret motives which
actuate the scholars and chief men of a sect, we should find
often something wholly different from the pure love of the
truth. It is certain at least that there is no opinion so ab
surd that it cannot be embraced upon this basis, since there is
scarcely an error which has not had its partisans.
Th. It must, however, be admitted that in many instances
we cannot avoid yielding to authority. St. Augustine has pro
duced quite a remarkable book "I)e utilitate credendi,"1 which
deserves to be read on this subject, and as for the received
opinions, they have for themselves something approaching to
that which gives what is called presumption with the juriscon
sults : and although we are not obliged to follow them always
without proofs, we are no more authorized to destroy them in
the mind of another without having contrary proofs. This it
is which does not allow us to change .anything without reason.
1 Cf. Opera, Benedictine ed., Vol. 8, pp. 45-70, Paris, 1688; Migne, Patrol,
s. Lat., Vol. 42 [Vol. 8 of Augustine], pp. 65-92. — TR.
CH. xx] ON HUMAN UNDERSTANDING 617
Tlie argument drawn from the great number of the approvers
of an opinion has been much disputed since the late M. Nicole
published his book on the church ; * but all that may be drawn
from this argument, when the question is of approving a reason
and not of attesting a fact, may be reduced merely to what I
have just said. And as one hundred horses do not run faster
•than one horse, though they can draw more, so it is with one
hundred men as compared with one single man ; they cannot
go more justly, but they will work more effectively; they can
not judge better, but they will be capable of furnishing more
matter upon which the judgment may be exercised. This is
the meaning of the proverb : plus vident oculi quam octtlus. We
notice it in the councils, where really a multitude of considera
tions are put upon the carpet which would perhaps escape one
or two, but they run a risk often of not taking the better side
in concluding upon all these considerations, when there are
no skilful persons charged with directing and weighing them.
Hence some judicious theologians of the Roman party, seeing
that the authority of the church, i.e. that of the most exalted
in dignity and the most supported by the multitude, could not
be certain in a matter of reasoning, have reduced it to the mere
attestation of the facts under the name of tradition. This was
the opinion of Henry Holden,2 an Englishman, doctor of the
Sorbonne, author of a book entitled " Analysis of the Faith,"
in which, following the principles of the " Common! tor ium " of
Vincent de Lerins,3 he maintained that we cannot make new
1 Cf. ante, p. 530, note 1. — TR.
2 Henry Holden, 159(5-1(>(>2, was an English Roman Catholic divine, who
graduated at the Sorbonne, and was appointed Professor of Theology there.
In 1(547 he petitioned the House of Commons for toleration of the Catholics,
provided they would take the oath of allegiance. His IHvinse Fidei Analysis,
a concise exposition of the Catholic articles of faith as distinguished from
matters of opinion, appeared at Paris, KJ52, with an appendix consisting of a
short treatise on Schism. It was reprinted at Paris, 1(585, 17(17, at Cologne,
1(555, 1782, Eng. trans., by " W. (4.," 1(558. Dupin, who gives a full abstract
of the book in his Bib!, des Auf. cedes., 1711, torn. 17, pp. 194-203, considers
him one of the ablest controversialists of his time. In 1(550 he was engaged
in a controversy with Antoine Arnauld, the Jansenist (cf. ante, p. 4(53, note 4),
and his letters to Arnauld were printed in later editions of the Analysis. — TR.
3 St. Vincent of Lerins, of Gallic origin, who died about 450. His Adversus
pro/anas omnium novitates Hssreticorum Commonitoriwn, written in 434,
three years after the Council of Ephesus, energetically affirms the authority
of tradition against all religious and doctrinal innovations. In chap. 2 of this
short treatise occurs the famous threefold test of orthodoxy : " Quod semper,
618 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
decisions in the church, and that all the bishops assembled in
council can do is to attest the fact of the doctrine received in
their dioceses. The principle is specious so long as we continue
in generalities ; but when we come to the fact, it is found that
in different countries different opinions have been received for
a long time ; and in the same countries also they have gone
from one extreme to another, notwithstanding the arguments
of Arnauld against insensible changes ; besides often without
confining themselves to attest them, they have taken it upon
themselves to judge. It is also at bottom the opinion of Gret-
ser,1 a learned Jesuit of Bavaria, author of another Analysis of
Faith, approved by the theologians of his order, that the church
may judge controversies by making new articles of faith, since
the assistance of the Holy Spirit is promised it, although most
frequently they try to disguise this view, especially in France,
as if the church were only to explain doctrines already estab
lished. But the explanation is a statement already received,
or a new one which they believe may be drawn from the re
ceived doctrine. Practice is most frequently opposed to the
first sense, and in the second, what can the new statement
which is established be but a new article ? I am not, however,
of the opinion that we despise antiquity in the matter of relig
ion; and I also believe that we may say that God has pre
served the truly ecumenical councils hitherto from all error
contrary to wholesome doctrine. For the rest, sectarian prej
udice is a strange thing. I have seen people embrace with
ardor an opinion for the sole reason that it is received in their
order, or even solely because it is contrary to that of a man of
a religion or of a nation which they do not like, although the
quod ubique, quod ab omnibus creditum est." The work has been edited by
Baluze, Paris, 16(53, 1G(>0, 1(584, Kliipfel, Vienna, 1805), Pusey, Oxford, 1838,
Herzog, Breslau, 1839, and others; Eng. trans, by Flower, London, 1866.
See also Migne, Patrol. Theol. cur. compl., Vol. 1, p. 911, Paris, 1^46. A
full account of it is given in Sraith-Wace, Diet, of Christ. Bioy., 4, 1154-
1158. — TR.
1 Jac. Gretser, 15(51-1(525, a learned Jesuit, was Professor of Philosophy
and various parts of Theology at Ingolstadt for twenty-four years. A man
of immense erudition, and a voluminous author, he was lacking in taste and
critical power, and was very harsh and bitter in discussion. It is said of him
that, when asked by the magistrates of Marckdorf in Swabia, his birthplace,
for his portrait to be placed in the town hall, he refused it, saying they had
no place therein for the head of an ass. His complete works appeared at
Ratisbonne, 1739 «?., 17 vols., fol. — TR.
CH. xx] ON HUMAN UNDERSTANDING 619
question had almost no connection with the religion or the
interests of the people. They did not know perhaps what was
in reality the source of their zeal ; but I knew that, upon the
first news that such an one had written this or that thing, they
would ransack the libraries and puzzle their brains to find
something to refute it. This it is which is practised so often
by those who maintain theses in the universities and who seek
to distinguish themselves against their adversaries. But what
shall we say of the doctrines prescribed in the Symbolic books
of the sect, even among l the Protestants, which we are often
obliged to embrace with an oath ? which some think signi
fies with us only the obligation to profess what these books
or formularies contain of Holy Scripture ; in which they are
contradicted by others. And in the religious orders of the
Roman party, without contenting themselves with the doctrines
established in their church, they prescribe narrower limits to
those who teach them ; witness the propositions the teaching
of which in their schools the General of the Jesuits, Claudio
Acquaviva2 (if I am not mistaken), defends. It would be well
(to mention it in passing) to make a systematic collection of
the propositions determined and censured by councils, popes,
bishops, superiors, faculties, which would be of use in ecclesi
astical history. We may distinguish between teaching and
embracing an opinion. There is no oath in the world nor pro
hibition which can force a man to abide in the same opinion,
for opinions are involuntary in themselves : but he may and
should abstain from teaching a doctrine which is regarded as
dangerous, unless he finds himself compelled thereto by his
conscience. In this case he must declare himself sincerely and
leave his post when he has been charged with teaching 5 sup
posing, however, that he can do so without exposing himself
to an extreme danger which might force him to leave without
1 Gerhardt, Erdmann, and Jacques read: " parmi " ; Janet reads : "par,''
i.e. "by."— TR.
2 Claudius Aquaviva, 154.3-1615, General of the Jesuits, 1581-1(515. For a
brief account of his Ratio Studioriim, 1599, c/. Hughes, Loyola and the Edu
cational System of the Jesuits, pp. 141 sq. (in The Great Educators Series, ed.
by Nicolas Murray Butler), New York: Chas. Scribner's Sons, 1892. For the
text of the Ratio, and a full account of its growth from its preliminary to its
final form, with the letters of Aquaviva and other documents, cf. Monument a
Germanise, Psedagogica, Berlin, A. Hofmann & Co., 188(5 sq., Bd. V., Tom. II.
— TR.
620 LEIBNITZ'S CRITIQUE OF LOCKE [BK. rv
fame. We see but little other means of reconciling the rights
of the public and of the individual ; the one being under obli
gation to prevent what it judges bad, and the other not being
able to dispense with the duties demanded by his conscience.
§ 18. Ph. This opposition between the public and the indi
vidual and even between the public opinions of different sects
is an inevitable evil. But often these very oppositions are only
apparent and consist only in the formulas. I am obliged also
to say, in order to be just to the human race, that there are not
so many people involved in error as is ordinarily supposed.
Not that I think that they embrace the truth, but because in
reality upon the doctrines upon which they make so much stir,
they have absolutely no positive opinion, and because without
having examined anything and without having in the mind the
most superficial ideas upon the matter in question, they are
resolved to hold themselves fast to their party, as soldiers who
do not examine the cause they defend : and if the life of a man
shows that he has no sincere regard for religion, it is sufficient
for him to have the hand and tongue ready to maintain the
common opinion, in order to commend himself to those who can
procure him support.
Til. This justice which you render to the human race does
not redound to its praise ; and men would be more excusable in
following their opinions than in disguising them for the sake
of their interests. Perhaps, however, there is more sincerity in
their deeds than you seem to give any one to understand. For
without any knowledge of a reason, they can perhaps attain to
an implicit faith by submitting themselves in general and some
times blindly, but often in good faith, to the judgment of others
whose authority they have once recognized. It is true that the
interest they find therein contributes to this submission, but
this does not prevent them at last from forming an opinion.
They are contented in the Roman church with this almost
implicit faith, not perhaps having any article thereupon, due to
the revelation which is judged absolutely funrldtnenhd thereto
and which is considered as necessary necessitate medii, i.e. the
belief of which is a condition absolutely necessary to salvation.
And they are all necessitate praacepti, by the necessity therein
taught of obeying the church, as they call it, and of giving all
attention to that which is proposed therein, all under pain of
en. xxi] ON HUMAN UNDERSTANDING 621
mortal sin. But this necessity demands only a reasonable docil
ity and does not compel absolute assent, according to the most
learned doctors of this church. Cardinal Bellarmine himself
believed, however, that nothing was better than this faith of a
child who submits himself to an established authority, and he
relates with approval the statement of a dying man, who escaped
the devil by this circle, which they heard him often repeat :
I believe all that the church believes,
The church believes what I believe.
CHAPTER XXI
OF THE DIVISION OF THE SCIENCES
$ 1. Ph. Here we are at the end of our course, and all the
operations of the understanding are explained. Our purpose is
not to enter into the detail indeed of our knowledge, yet it will
perhaps be proper here, before we conclude, to make a general
review by considering the division of the sciences. All that
can enter into the sphere of human understanding is either the
nature of things in themselves, or in the second place, man in the
character of an agent, tending towards his end and in particular
towards his happiness, or in the third place the means of acquir
ing and communicating knowledge. Science then is divided
into three kinds. § 2. The first is Physics or Natural Philoso
phy, which comprises not only bodies and their properties, as
number, figure, but also spirits, God himself and the angels.
§ .'). The second is Practical Philosophy or Ethics, which teaches
the means of obtaining good and useful things, and proposes to
itself not only the knowledge of the truth, but also the practice
of that which is right. § 4. Finally, the third is Logic or the
knowledge of signs, for Aoyo? signifies word. We need signs of
our ideas to enable us to communicate our thoughts to one
another, as well as to register them for our own use. Perhaps
if we should consider distinctly and with all possible care that
this last kind of science revolves about ideas and words, we
should have a logic and criticism J different from that which has
i Locke has: "critic," Philos. Wks., Vol. 2, p. 338, Bohn's ed.; Fraser
L'H-kr's Exxait concerning Hainan Understanding, Vol. 2, p. 462. « TR.
622 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
hitherto been seen. And these three kinds, Physics, Ethics,
and Logic, are like three great provinces in the intellectual
world, entirely separate and distinct the one from the other.
Tli. This division has already been a celebrated one among
the ancients ; for under Logic they comprised, as you do, all
that relates to words and to the explication of our thoughts :
Artes dfcendi Nevertheless, there is some difficulty therein;
for the science of reasoning, of judgment, of invention appears
very different from the knowledge of the etymologies of words
and the use of languages, which is something indefinite and
arbitrary. Farther, in explaining words, we are obliged to make
an incursion into the sciences themselves, as appears by the
dictionaries ; and on the other hand, we cannot treat of science
without giving at the same time dehiiitions of the terms. But
the principal difficulty found in this division of the sciences is
that each part appears to absorb the whole ; in the first place,
Ethics and Logic will fall into Physics, taken as generally as
you have just stated; for in speaking of spirits, i.e. of sub
stances having understanding and will, and in explaining this
understanding to the bottom, you will make it include all logic :
and in explaining in the doctrine of spirits what belongs to the
will, it would be necessary to speak of good and evil, of happi
ness and misery, and it will only depend upon you to push this
doctrine far enough to make it include all practical philosophy.
In return, all might be included in practical philosophy as serv
ing- for our happiness. You know that Theology is rightly con
sidered as a practical science, and Jurisprudence as well as
Medicine are not less so ; so that the doctrine of human happi
ness or of our good and ill will absorb all these branches of
knowledge, should we desire to explain sufficiently all the means
serving the end which reason proposes to itself. Thus it is
that Zwiiiger has included all in his " : Magnum theatrum vitte
humani." which Beyerling has disturbed by arranging in alpha
betical order.1 And in treating all matters in dictionaries fol-
1 Laurent Beyerlinck, or Beierlynck, 1578-1027, a Flemish scholar, Professor
of Poetry and Rhetoric at Vaulx, and Canon of the Antwerp Cathedral, j>iii>-
lished, with additions and corrections, the Theatrum vitse humanse of Zwinjjer
(cf. ante, p. 548, note 1), with the title Magnum theatrum. vit& hum«)i:i\
Cologne, 1031, 8 vols., fol. Schaarschmidt states that this new edition in
alphabetical order is, in fact, worth less than the old redaction of the book,
which handled the materials systematically in their essential aspects. — Tu.
CH. xxi] ON HUMAN UNDERSTANDING 623
lowing the order of the alphabet, the doctrine of languages
(which you with the ancients put in Logic), i.e. in discursive
logic, takes possession in its turn of the territory of the two
others. Here, then, your three great provinces of encyclopedia
are in continual war, since one is always encroaching upon the
rights of the others. The Nominalists believed that there were
as many particular sciences as truths,1 which they composed
after the wholes according as they arranged them; and others
compare the entire body of our knowledge to an ocean, which
is all of a piece and which is divided into Caledonian, Atlantic,
Ethiopic, Indian only by arbitrary lines. It is usually found
that one and the same truth may be put in different places,
according to the terms it contains, and also according to the
mediate terms or causes upon which it depends, and according
to the inferences and results it may have. A simple categoric
proposition has only two terms ; but a hypothetic proposition
may have four, not to speak of complex statements. A remark
able history may perhaps be placed in the annals of universal
history and in the history of the country where it happened,
and in the history of the life of a man who was interested
therein. And suppose the question therein concerns some fine
precept of morals, some stratagem of war, some invention use
ful in the arts which serve the conveniences of life or the health
of men. this same history will be related to some purpose in the
science or art it concerns, and indeed it can be mentioned in
two parts of this science, viz., — in the history of the discipline
in order to recount its efficient growth, and also in the precepts
to confirm them or illuminate them by examples. For example,
what is very properly told in the life of Cardinal Ximenes, that
a Moorish woman cured him by rubbings only of a hectic almost
desperate, deserves also place in a system of medicine, as well
in the chapter on hectic fever, as when the question concerns a
1 The phrase " as many sciences as truths " -— " tot esse scientias quot veri-
tates " — is, as Schaarschmidt says, "the sharpest expression of nominalistic
individualism." "' According to Nominalism, we have a knowledge of partic
ulars only, all nniversals being merely Jiff went ft mentis, products of abstrac
tion. Hence true and genuine science always relates to particulars only, and
thus there are as many sciences as (particular) truths."
On Leibnitz's studies of Nominalism, cf. Guhrauer, Leibnit. Dissc.rtatlo de
princ. Individ., pp. .'>9 sq., Leibnitz, De stilo philo*. Nizolii, § 28j Gerharflt,
4, ir>7-158, Erdmann, 08-09. — TR.
624 LEIBNITZ'S CRITIQUE OF LOCKE [HK. iv
medicinal diet comprising these exercises; and this observation
will serve also the better to discover the causes of this disease.
But we might further speak of this in medicinal logic, where
the question is about the art of discovering remedies, and in the
history of medicine, in order to show how remedies have come
to the knowledge of men, and that it is often by the aid of sim
ple empirics and even charlatans. Beverovieius,1 in a remark
able book on ancient medicine, drawn wholly from authors not
physicians, would have rendered his work still more useful, if
he had passed down to modern authors. \Ve see by this that
one and the same truth may have many places according to the
different relations it can have. Those who arrange a library
very often do not know where to place certain books, being in
suspense between two or three places equally suitable. .But
let us now speak only of general doctrines and put aside partic
ular facts, history and languages. T find two principal dispo
sitions of all doctrinal truths, each of which should have its
deserts and which it would be well to unite. The one would
be synthetic and theoretic, ranking truths according to the order
of proofs, as the mathematicians do, so that each proposition
would come after those on which it depends. The other dispo
sition would be analytic and. practical, commencing with the end
of men. i.e. with the goods whose consummation is happiness,
and seeking in order the means available for acquiring these
goods or avoiding the contrary evils. These two methods have
place in general encyclopedia, while some have practised them
in particular sciences ; for geometry itself, treated synthetically
by Euclid as a science, has been treated by some others as an
art, and might nevertheless be treated demonstratively under
this form, which would show indeed some invention: as if some
'Jan van Be ver wyck, — Latin Beverovieius, — 1594-1(547, a noted Dutch
physician, who studied at Leyden, Caen, Paris, Montpelier and Padua, whore
he received his M. D., and on his return became Professor of Medicine at Dor
drecht and physician to the city, in which also lie held several civil offices,
among them that of burgomaster. He labored to simplify the methods of pre
scribing for disease. He published a number of books distinguished for purity
of style and relation of facts, and which, adorned with copper-plates and with
the verses of Jakob Cats, 1577-16<>0, one of the oldest and most popular Dutch
poets, "made in his time much sensation and met with much approbation."
Among them was the If Jen inedicinx -netemni, Lugd. Bat., 1637, l'2mo, here
mentioned by Leibnitz. His entire works were published at Amsterdam,
H5T>1, etc. — TR.
•n. \xi] OX HUMAN UNDERSTANDING
one proposed to measure all kinds of plane figures, and begin
nhii- with rectilinears, reflected that they may be divided intc*
triangles and that each triangle is half of a parallelogram, aim
that parallelograms can be reduced to rectangles whose measure-
is easy. But in writing the encyclopedia, following both thesfe
two dispositions together, we might take measures for references
in order to avoid repetitions. To these two dispositions the third
according to the terms should be joined, which in reality woidd
be only a kind of index, either systematic, arranging the terms
according to certain predicaments which would be common
to all the notions, or alphabetical according to the languages
received among scholars. Now this index would be necessary
iu order to find together all the propositions into which the
term enters in a sufficiently remarkable manner ; for according
to the two preceding ways, where the truths are arranged accord
ing to their origin or use, truths concerning one and the same.
term cannot be found together. For example, it was not per
mitted Euclid, when he was teaching how to find the half of an
angle, to add the means of finding its third, because he would
have been obliged to speak of the conic sections, knowledge of
which lie could not yet assume in this place. But the index
may and should indicate the places where are found the impor
tant propositions which concern one and the same subject. And
we still lack such an index in geometry, which would be of great
use in facilitating indeed invention and in pushing the science,
for it would relieve the memory and often spare us the trouble
of seeking again that which has already been found. And these
indices would further be of use for a much stronger reason in
the other sciences, where the art of reasoning has less power,
and would be above all extremely necessary in Medicine. But
the art of making such indices would be no slight one. Now
considering these three dispositions, I find it remarkable that
they correspond to the ancient division, which you have renewed.
which divides science or philosophy into theoretic, practical and
discursive, or rather into Physics, Ethics, and Logic. For the
synthetic disposition corresponds to the theoretic, the analytical
to the practical, and that of the index according to the terms to
logic : so that this ancient division does very well, provided we
understand these dispositions as I have just explained, i.e. not
as distinct sciences, but as different arrangements of the same
2?.
626 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv
truths as far as we judge it advisable to repeat them. There
is also a civil division of the sciences according to the faculties
and professions. We make use of it in the universities, and in
the arrangements of libraries ;x and Draudius,2 with his continuer
Lipenius,3 who have left us the amplest, but not the best cata
logue of books, instead of following the method of the Pandects
of Gesner,4 which is wholly systematic, have contented them
selves with the use of the great division of the materials (much
1 For Leibnitz's sketch of a library classification and catalogue, cf. his Idea
Leibnitiana Bibliothecse Publicse secundum classes scientiarum ordinandss,
Dutens, 5, 209-214. Cf. also his Representation a S. A. S. le Due de Wolfen-
buttel,povrl'encourager a I'entretien de saBibliotheque, ibid., 5, 207-208; the
same, in German, Guhrauer, Leibnitz's Deutsche Schrift., 2, 470-472. — TR.
2 Georg Draud, 1573-1630 or 1635, a student at Marburg University and
afterwards a proof-reader at Frankfort, Basle, and at the famous typography
at Feyerabend, and minister of the gospel at Gros-Carbeu, Ortenberg and
Dauernheim, was the first to attempt an extended systematic bibliography.
His Bibliotheca classica sive catalogue officinalis, in quo singuli singularuni
facultatu/n ac professionum libri — secundum artes et ordine alphabetico
recensentur, Frankfort, 1611, was the most complete bibliography of printed
books that had then appeared. A 2d ed., increased by all the books printed
from 1611-1(>25 of which the editor had knowledge, appeared in 1625. — TR.
3 Martin Lipenius, 1630-KJ92, a learned German bibliographer, who studied
at Wittemberg, and was co-rector of the gymnasium at Halle, and of the acad
emy at Lubeck, and rector and professor in the gymnasium at Stettin. He
published Bibliotheca realis juridica, 1(>79, the most valuable of his series,
edited with additions by F. W. Struve, in 1720, by G. A. Jenichen, 1709-1759.
a jurist, philologian and historian, with corrections in 1736. and a supplement
in two parts, 1742; also several subsequent editions with corrections and addi
tions; Bibliotheca realis medica, 167!), philosophic^, 1(W2, theologica, 1(585.
They were called realis because the books were listed in the alphabetical order
of subjects and not under the names of their authors. — TR.
4 Conrad Gesner, 151(5-1565, called the " German Pliny," because of his
vast erudition, was Professor of Greek, 1537, at Lausanne, and of Physics and
Natural History, 1541, at Zurich. He made " the first comprehensive attempt
at a general encyclopedia of literature, constructed in the form of a catalogue "
in his Bibliotheca universally. The work contained the titles of all then known
books, existent or lost, published or announced, in Hebrew, Greek and Latin,
giving under each important name a vast amount of bibliographical informa
tion and criticism, original and selected, and often some specimens of their
style. The first vol., Zurich, 1545, is arranged alphabetically according to
the authors' names: the second, entitled Pandectse sire partitionum unive.r-
salhim, lib. XXI., — totius philosophise et omnium bonarum artium atque stu-
diorum locos communes et ordines unii-ersales simul et particulars, — Zurich,
1548, is arranged according to subjects and divided into 19 books, book 21, a
theological encyclopedia, not being published till 1549, and book 20, the
medical writings, never appearing because in the author's view too imperfect
for publication. It was reprinted and greatly enlarged by Simler in 1574, and
by J. J. Fries, Ziirich. 1583. — TR.
CH. xxi] ON HUMAN UNDERSTANDING 627
the same as the libraries) following the four faculties (as they
are called) of theology, jurisprudence, medicine and philosophy,
and have afterwards arranged the titles of each faculty accord
ing to the alphabetical order of the principal terms entering
into the inscription of the books : this lightened the task of
these authors, because they had no need to see the book or to
understand the matter which the book treats, but it does not
sufficiently serve others, at least it does not make references in
the titles to others of parallel signification ; for not to speak of a
number of mistakes they have made, we see that often one and
the same thing is called by different names, as, for example,
obserixitiones juris, miscellanea, conjectanea, electa, semestrittj
probabilia. benedicta, and a multitude of similar inscriptions ;
such books of the jurisconsults signify only the miscellanies of
the Roman Law. This is why the systematic disposition of the
materials is without doubt the best, and we may join with it
alphabetical indices very full according to the terms and the
authors. The civil and received division, according to the four
faculties, is not to be despised. Theology treats of eternal
felicity and all that relates thereto, so far as it depends on the
soul and the conscience ; it is like a jurisprudence w^hich regards
what is said to exist de foro interno and employs invisible sub
stances and intelligences : Jurisprudence has for its object gov
ernment and the laws, whose end is the happiness of men so
far as the external and sensible can contribute thereto ; but it
regards principally only that which depends upon the nature
of the spirit, and does not enter much farther into the detail of
material things whose nature it assumes in order to employ
them as means. Thus is it relieved at once of an important
point which concerns the health, strength and perfection of the
human body, the care of which is given to the faculty of Medi
cine. Some have believed with some reason that wre might add
to the others the Economic Faculty, which would contain the
Mathematical and Mechanical Arts, and all that concerns the
detail of the subsistence of men and of the conveniences of life,
in which Agriculture and Architecture would be included. But
we abandon to the faculty of Philosophy all which is not
included in the three faculties which we call superior. We do
this quite badly, for we do it without giving means to those
who are of this fourth faculty for perfecting themselves by
ttt8 LEIBNITZ'S CRITIQUE OF LOCKE [»K. iv
practice as those can do who teach the other faculties. Thus
the mathematics perhaps excepted, we considev the faculty of
philosophy only as an introduction to the others.1 This is why
we wish the youth to learn history, and the arts of speaking
and some rudiments of theology and natural jurisprudence,
independent of divine and human laws, under the title of meta
physics or psychology, ethics and politics with a little of physics
also, in order to serve as young physicians. This, then, is the
civil division of the sciences following the bodies and profes
sions of the scholars who teach them, without speaking of the
profession of those who work for the public otherwise than by
their discourses and who ought to be directed by true scholars,
if the limits of knowledge were well understood. And even in
the more noble manual arts, knowledge has been very much
bound up with performance, and might be more so. As in fact
they are joined together in medicine, not only formerly among
the ancients (where physicians were also surgeons and apothe
caries), but also to-day especially among the chemists. This
alliance also of practice and theory finds itself at variance both
among those who teach what are called exercises, as also among
the painters, or sculptors and musicians, and among some other
kinds of virtuosi. And if the principles of all these professions
and arts, and even of the trades, were taught practically among
the philosophers, or in some other faculty of scholars as they
might be, these scholars would be truly the teachers of the
human race.2 But it would be necessarv to change much of
1 I.e. in the broader sense of the term in which it is equivalent to the
Humanities, — artes libemlex, — the liberal education, disciplinary, stimulative
and cultural of the student's entire powers, which was considered until very
recently, and is regarded even nowr by many of the deepest and farthest-sighted
thinkers on education, as an essential precedent and preparation for all later
special professional study. The custom of regarding the Faculty of Arts
or Philosophy as introductory to that of Theology, Medicine and Jurispru
dence, goes back to the university curricula of the Middle Age, the Trivium
and the Quadrivium, with their respective degrees of A.B. and A.M.. which in
their essential character and principles, with the necessary changes incident
to an advancing civilization, have been, till within a short time at least, the
controlling influence in shaping the curricula and methods of all modern col
legiate and university education. — TR.
2 On this, as on every subject he touched, Leibnitx utters a suggestive and
stimulating thought, which has in recent times brought forth much fruit in
the establishment and maintenance of technical and art schools of every kind.
- TR.
xxi] ON HUMAN UNDERSTANDING
the present state of thing's in literature and the education of the
youth, and consequently of the government. And when I con
sider how much men have advanced in knowledge in the last
century or two, and how easy it would be for them to go incom
parably farther in order to render themselves happier, I do not
despair that a considerable improvement will come in a more
tranquil period under some great prince whom God will be able
to raise up for the good of the human race.1
1 Leibnitz constantly labored to secure the sympathy and active co-opera
tion of the ;> great princes " in the initiation and furtherance of learning; sci
ence, and the higher ideal interests of mankind in general, a conspicuous
example of his success being that of the great reformatory genius of his time,
Peter the Great of Russia. Their correspondence is found in Foucher de
Careil, (Euvres de Leibniz, 7, .'595-598. Cf. also W. Guerrier, Leibniz in seine H
Beziekungen zt( Russland uitd Peter dern Grossen, St. Petersburg and Leip
zig, 1873; Foucher de Careil, Leibniz et Pierre le Graml, Paris, 1873. Fora
general account of his various efforts in this direction, cf. Fischer, (le.xch.. (I.
a. PhifoM., Vol. 2, Leibniz, 3d ed., 1889, pp. 211-249; and for a brief account,
Merz, Leibniz (Blackwood's Philos. Class.), pp. 74-8:1.. — TR.
APPENDIX
LEIBNITZ TO JACOB THOMASIUS1
April 20-30, 1669
[From the Latin]
How much that yev/Ao. of philosophical history of yours has made
the mouths of all water cannot be told ; for it is apparent how much
difference there is between mere enumerations of names and those
profound views concerning the connections of opinions. And cer
tainly all acquainted with the subject that I hear speak of your essay
(you know that I never flatter), unanimously affirm that from no
one man can a complete body of philosophical history preferably be
expected. Very many skilled in antiquity rather than in art have
given us Lives rather than opinions. You will give the history not of
philosophers but of philosophy. They say in England that Joseph
Glanvill's History of the growth of the sciences since Aristotle is in
press.2 But I think he will pursue for the most part the mathemati
cal, mechanical, and physical periods of this inquiry only, so I think
1 Gerhardt, Leibniz, philos. Schrift.l, 15-27; Erdmann, 48-54; Dutens, 4,
Pt. I. 7-19; Kortholt, Leibnit. epist. addiversos, Lipsiae, 1734-42,2, 121-142.
Kortholt's text gives the piece as printed by Leibnitz in his edition of Nizo-
lius, and differs considerably from that given by Gerhardt, which is the text
followed in this translation. Cf. also, Gerhardt, Leibniz, philos. Schrift., 4,
162-174. In this " impression," says Gerhardt, Einleitung, ibid., p. 9, note **,
" the copy of the Royal Library at Hanover has been used, in which are found
MS. notes of Leibnitz." — TR.
2 Joseph Glanvill, 1636-1680, Court Chaplain to Charles II., published his
defence of the Royal Society of London, entitled Plus Ultra, or the Progress
and Advancement of Knowledge since the days of Aristotle, in 1668. In his
idea of causation Glanvill was a predecessor of Hume. His Scepsis scientifica,
or Vanity of Dogmatising, London, 1665, edited by John Owen, 1885, and his
De incrementis scientiarum, London, 1670, attacked the Aristotelian and Car
tesian dogmatism. Though a thorough-going sceptic in the direction of the
scholastic philosophy, he was opposed to the materialism of Hobbes. Some
account of Glanvill's views will be found in Lecky, Rationalism in Europe,
I, 129 sq. D. Appleton & Co., New York, 1876. — TR.
631
632 LEIBNITZ'S CRITIQUE OF LOCKE
he has forestalled you in nothing. But I wish that you would pro
duce a style and form for this more modern age and admonish our
inconsiderate youth that neither everything nor nothing is to be attrib
uted to the restorers. Bagheminus1 is not the only critic to whom you
are indebted ; there are the Patricii, Telesii, Campanella?, Bodini,
Nizolii, Fracastorii, Cardanii, Galilaei, Verulamii, Gassendi, Hobbii,
Cartesii, Bassones, Digbaei, Sennerti, Sperlingii, Derodones, Deusingii,
and many other names among whom the cloak of philosophy is
divided.2 To remind the world of these will be a diversion for you, a
profit to the public.
Who does not assent to your estimate of Bagheminus? There is no
skilful adjustment in hypotheses,3 no logical sequence of reasons, but
in a word strange notions; certainly unless he has something to
observe useful in special physics, he will better be silent. But
Scaliger, Sennert, and Sperling, — for he acknowledged himself a pupil
of this one also, — seem to me to be the parents of the opinion of that
one concerning God, the primary matter of things, who think that
forms are produced not from the passive power of matter, but
from the active power of the efficient one. Wherefore the conclu
sion is that they believe that God produces creatures rather from his
own active power, than from nothing by objective and as it were
passive power. God therefore in their opinion produces things out of
himself, and so will be the primary matter of things. But as to this
you will more properly judge.
As to Descartes and Clauberg, I think in brief with you that the
disciple is clearer than the master. Nevertheless, I should venture
again to affirm that hardly any one of the Cartesians have added any
thing to the discoveries of the master. Certainly Clauberg, Rsens.4
1 Cf. the letter of Jacob Thomasius to Leibnitz, October 2, 1668, Gerhardt,
Leibniz, philos. Schrift.,l, 14; Kortholt, Leibnit. Epistolse. ad diversos, 3,
35: "Bagheminus ille, cujus negotium geritur, Scabinus est Stetinensis, et a.
nostra turn theologica, turn philosophica facilitate petiit philosophise suae no vie
censuram. Theologi responderunt. A nobis nihil aliud repositum illi est,
quam disputatio mea, quse si in manus hominis pervenit, facile jndicabit, quo
in hanc novitatem animo simus." — TR.,
2 For some account of the lives and philosophy of the persons whose names
are here mentioned, cf. Lasswitz, Gesch. d. Atondstik ; Stockl, Gesch. d.
Philos. d. Mittelalters, III. [Vol. 4]. — Anton Deusing, 1612-1666 (not referred
to in the works cited), was a German physician and Professor of Medicine at
Groningen. He had an extended knowledge of philosophy, mathematics, and
oriental languages, and published many works, among them, De vero syxtv-
mate mundi, dissertatio mathematica, qua Copernici sy sterna mundi ref or ma-
tur, etc., Amsterdam, Elzevir, 1643, 4to.— TR.
3 Erdmann reads : " hypothesibus ejus," i.e. his hypotheses. — TR.
4 Jean de Raey, date of birth unknown, died 1702, was Professor of Philoso
phy in the University of Leyden 1652-16(58, and entered upon his Professorship
at Amsterdam in January, 1669, with an Oratio de sapientia veterum. In his
APPENDIX 633
Spinoza,1 Clerselier,2 Heerbord,3 Tobias Andre*,4 Henry Regius,5 have
published nothing but paraphrases of their master. But I call those
Cartesians only who follow the principles of Descartes, from which
number those great men Bacon, Gassendi, Hobbes, Digby, Cornelius
of Hogheland,6 etc., whom the common people confound with the
Clavis philosophise, naturalis sen introductio ad naturx contemplationem
Aristotelico-Cartesianam, 1654, 2d ed., 1677, he sought to improve and com
plete the doctrine of Aristotle through that of Descartes. He explained
Erkenntnisslehre wholly after the manner of Aristotle; but contested his
assumption of the eternity of the world or the diyine nature of the stars. He
discussed mainly the nature of matter and the origin of motion, wholly on a
("artesian basis. — TR.
1 In the impression of this letter given by Gerhardt, Leibniz, philos.
Schrift,, 4, 162 sq., Leibnitz has erased the names of Spinoza and Cornelius
van Hooghelande, and added after Bacon that of Galileo. This impression
omits also the names of Raeus and Clerselier. For the other textual changes.
cf. the impression itself. — TR.
2 Claude Clerselier, 1614-1684, the father-in-law of Rohault (cf. ante, p. 233,
n . 2) , was a zealous disciple of Descartes and edited some of his works : Le
monde, ou traite de la lumiere, Paris, 1677; Traite de Vhomme, Paris, 1664:
Les lettres de Rene Descartes, 3 vols., Paris, 1657-1667. —TR.
3 Adrian Heereboord, 1614-1659, Professor of Philosophy in the University
of Leyden, was one of the first and most zealous advocates of the new ten
dency of thought introduced by the philosophy of Descartes. He united to a
certain extent Cartesiauism with the traditional authority of Aristotle, evi
dence of which appears in his Parallelism us Aristotelicse et Cartesianse phi
losophise naturalis, 1643. Other writings of Heereboord are: Meleteniata
philosophica,\654:; Philosophia rationales, moralis, et naturalis, 1654, 2d ed..
1660; Philosophia pneumatica, 1659. — TR.
4 Tobias Andreae, 1604-1674, Professor of History and Greek Language at
Grouingen, successfully cultivated philosophy and became known as a zealous
partisan of the philosophy of Descartes. He wrote, in 1653, against Jacob
Revius, Assertio methodi Cartesianse, and was also author of Brevis expli-
catio, brevi explicatione mentis humanse Henr. Regii reposita. — TR.
5 Hendrik van Roy, 1598-1679, usually called Regius, was a Dutch physician,
who in 1638 became Professor of Botany and Theoretical Medicine at Utrecht.
He was a zealous disciple and advocate of the ideas of Descartes, until the
Voet-Schoock-Descartes controversy and Descartes' rejection of him as a true
representative of his views resulted in their falling out. Regius regarded the
soul as a mode of the bodily substance, and in physics, while resting through
out on Cartesian principles, differed from Descartes in his conception of
motion and rest. On this doctrine of Regius, significant for the problem of
body, cf. Lasswitz, Gesch. d. Atomistik, 2, 405-408. Regius published, among
other works, Fundament a physicse, Leyden, 1646; P/iilosophia naturalis,
Amsterdam, 1661. Dr. James Martineau, A Study of Spinoza, London,
Macmillan & Co., 1882, page 75, line 7, and foot-note 1, in translating " Regis "
instead of "Regius'' has misunderstood Leibnitz's reference and wrongly
attributed to him a " lapsus memorise." — TR.
6 Cornelius Van Hooghelande, a Catholic nobleman who lived at Leyden,
was a friend and disciple of Descartes. In his Cogitationes, 1646, Hooghelande
" so developed the fundamental doctrines of Descartes that the only Cartesian-
634 LEIBNITZ'S CRITIQUE OF LOCKE
Cartesians, must in a word be left out, since however they were either
the equals or even the superiors of Descartes in age and natural
capacities; I acknowledge that I am anything but a Cartesian.
That rule I hold common to all these renovators of philosophy, that
nothing is to be explained in bodies except by magnitude, figure, and
motion. In respect to Descartes I hold the argument only of his
method, for when we come to the present matter, he relaxed utterly
from that severity, and descended abruptly to certain extraordinary
hypotheses, a course which in his case Vossius rightly indeed repre
hended in his book on Light.
Wherefore I do not hesitate to say that I approve more things
in the books of Aristotle rrept (frvaiKrjs aKpocurews, than in the Medi
tations of Descartes ; so far am 1 from being a Cartesian. Xay more, I
would venture to add that all those eight books can be received with
out violation of the reformed philosophy. By which very method
those difficulties will ipso facto be met which you, most distinguished
man, are investigating in regard to the irreconcilable Aristotle.
For the conclusions of Aristotle concerning matter, form, privation,
nature, place, infinity, time, motion, are for the most part certain and
demonstrated, this one thing generally excepted, what he asserted
about the impossibility of a vacuum and motion in a vacuum. For
to me neither vacuum nor plenum is necessary, and the nature
of things seems capable of explanation by either method. In behalf
of the vacuum contend Gilbert, Gassendi, Gericke ; for the plenum,
Descartes, Digby, Thomas Anglus,1 Clerk- in his book " De plenitu-
dine mundi." For the possibility of each, Thomas Hobbes and Robert
Boyle. And I confess that, with difficulty indeed, yet without a
vacuum, the rarefactions of things can be explained. I saw recently
the book of John Baptist du Hamel,3 a French scholar, on the
ism of his work was the dedication.'' Descartes regarded him, says KUHO
Fischer, Descartes and his School, translated by Gordy, p. 503, "as a well-
disposed man without a calling to philosophy, and without understanding his
doctrine." Cousin, (Euvres de Descartes, 6, 279-281, gives a letter, with a
foot-note of an unknown editor stating his belief that Descartes wrote this
letter to Van Hooghelande in March, 16.'>6, at Amsterdam. — TR.
i Thomas White, 1582-1676, called Anglus, Albins, Candidas, etc., published
his Institutionum Peripateticarum ad menteni sanuni clarissimique Philoso-
phi Kenelmi Equltls Diybsei at Lyons, 164(5. Leibnitz refers to him briefly
in the Theoria mot us concreti, § 55 (Gerhardt, Leibniz, philos. Schrift., 4,
207; Math. Schrift., II., 2 [Vol. 6], 47), and in the Theoria mot us abstracti
(ibid., 4, 228; II., 2 [Vol.6], 67), as " subtilissimus " and " acutissimus." — TR.
'2 Gilbert Clerke, 1626-1697 ?, a mathematician and theological writer, in his
first work, De Plenitudine Mundi, etc., 1660, reviewed Descartes and attacked
Bacon and Hobbes, and published in 1662 his Tractatus de Rest ititt tone Cor-
porum, results of studies following Torricelli and Boyle. — TR.
3 Jean Baptiste du Hamel, 1624-1706, was a French experimental philoso
pher and astronomer, who lectured on physics and experimented so far as his
APPENDIX 635
harmony of ancient and modern philosophy, published not long
since at Paris, in which he elegantly expounds and often acutely
estimates the hypotheses of some of the most celebrated ancients
and moderns. He also has not a few words concerning the con
flicting views about the vacuum. As to the rest, scarcely any sane
man will call in question all the remaining things discussed by
Aristotle in Bk. VIII. Phys. and the entire Metaphysics, Logic,
and Ethics. Who does not admit the substantial form also ; namely,
that by which the substance of one body differs from the substance
of another body? Nothing is truer than primary matter. This one
thing is in question, whether the abstract discussions of Aristotle con
cerning matter, form, and change, are to be explained by magnitude,
figure, and motion. The Scholastics deny, the Reformers affirm, it.
The opinion of the Reformers seems to me not only the truer, but the
more in harmony with that of Aristotle ; I will speak briefly of each.
And first of Aristotle. For that the Scholastics strangely pre-
verted his meaning, to whom is it better known than to you,
most distinguished man, who have been the first to bring forth
into the light a good many of this class of errors? Since with
you in metaphysics Soner J and Dreier;2 in logic Viottus, Zabarella,3
position and the instruments then existing allowed. He published, among
other works, Astronomia, physica, and De meteoribus et -fossilibus, Paris,
1660: De consensu veteris et novse philosophise, Paris, 1663 and later editions,
the work here referred to by Leibnitz; De corporum affectionibus, 1670; his
Opera, Norimberga, 1681. Cf. Lasswitz, Gesch. (L Atomistik, 2, 493, 494. — TR.
1 Ernst Soner, 1572-1612, was Professor of Philosophy and Medicine at
Altdorf, and in philosophy an Aristotelian. He was the author of many
Disputationes, the greater part of which appeared in Felwinger's Philosophic
Altdorfiana, Norimberga, 1644; also of Commentaries on Aristotle's Meta
physics and Physics, 1607 ; he also wrote against eternal punishment in his
Demonstrationes quid seterna impiorum supplicia -non arguant Dei justitiam
sed in justitiam, and some medical works. Cf. Magn. Dan. Omeisius, Gloria
Academise Altdorjiause, etc., Altdorf, 1683. Leibnitz in his Preliminary
Dissertation to his edition of Nizolius (Gerhardt, 4, 155; Erdmann, 68 a;
Dutens, 4, Pt. L, 57) speaks of his contribution, together with that of Dreier,
to the understanding of Aristotle's Metaphysics ; and in the Theodicee, Pt. III.,
§ 266, of his argument against eternal punishment. — TR.
2 Christian, or Peter, Dreier, 1(510-1688, was Professor of Theology at Kon-
igsberg, and published his Sapientia sen Philosophia prim a, ex Aristotele
ej usque optimis commentatoribus, conscripta, Konigsberg, 1644, 4to. Leibnitz
refers to him in his Preliminary Dissertation to Nizolius (Gerhardt, 4, 155 ;
Erdmann, 68 a ; Dutens, 4, Pt. I. 57) and also in the Theodicee, Pt. II., § 184:
" M. Dreier de Konigsberg a bieu remarque que la vraie metaphysique
qu'Aristote cherchait, et qu'il appelait TTJV ^rovnevriv, son desideratum, etait
la the'ologie." — TR.
3 Jacopo Zabarella, 1533-1589, was a teacher of Logic at Padua. His De rebus
naturiilib-us, lib. XXX., appeared at Col., 1590, fol. ; his Opera logica, Col.,
1597, fol. : both also in several later editions. An account of Zabarella will be
found in Stockl, Gesch. d. Philos. d. Mittelalters, III. [Vol. 4], 263-272.— TR.
636 LEIBNITZ'S CRITIQUE OF LOCKE
Jung,1 in civics Jason Denores,2 Piccart,3 Conring, Felden,4 Durrius,5
and many others, acknowledge this, why, I pray, shall we not suspect
the same or worse in physics, aids in the knowledge of which must be
sought from sense and experiment, of which means the Scholastics
confined for the most part in closed monasteries were absolutely
deprived ? It is probable enough, therefore, that in physics they were
deceived ; how if I shall show more than this, that it is altogether
certain V In which thing I may be engaged again in a twofold way.
For either it is shown that the Reformed Philosophy can be recon
ciled with the Aristotelian and is not contrary to it, or further, it
is shown that the one not only can, but also must, be explained by the
other; nay, rather, that the very things which are discussed with
so much pomp by the moderns flow from the Aristotelian principles.
By the former way the possibility, by the latter the necessity, of the
reconciliation is accomplished, although in this very instance if
a possible reconciliation is shown, the thing is accomplished. For
1 Joachim Jung, 1587-1657, an eminent mathematician and physicist, and
an earnest advocate of the corpuscular theory, published Loylca Hambury-
ensis, Hamburg, 1638, 8vo; et recensente Joh. Vegetio, 1681, 8vo ; and various
disputations. Leibnitz refers to his Geometi-la empirlca, Hamburg, 1681, 8vo,
in the T/teodicee, Pt. II., § 214. For an account of him and his corpuscular the
ory, cf. Lasswitz, Gesch. d. Atomistik, 2, 245-261; E. Wohlwill, J. Jung ins
and die Erneuruny atomistischer Lehren im 17 Jahrhundert, Hamburg, 1887 ;
G. E. Guhrauer, J. Jung and sein Zeitalter, Stuttgart u. Tubingen, 1859. — TR.
2 Jason Denores, died 1590, was well acquainted with the peripatetic phi
losophy, and published De.ll" ottima repubtica, Venice, 1578, 4to ; and De con-
fifitutione philoft. Arlstotelis, Patavii, 1584, 4to. — TR.
;J Michael Piccart, 1574-1620, Professor of Philosophy and Poetry at Altdorf ,
was one of the most learned men of his times, and especially distinguished as
an interpreter of Aristotle. Among his works were Isayoge in lectionem
Arlstotelis. Nuremberg, 1605, 8vo, reprinted with the notes of J. C. Durrius,
Altdorf, 1660. 1666, 8vo; Organ um Aristotelicum in qusest. etrespons. redac-
tam, Leipzig, 1613, 8vo ; In politicos libros Arlstotelis, Leipzig, 1615, 8vo, Jena,
1659. 8vo, a highly esteemed work, which was reprinted with the title: Aryu-
menta librorum politicorum Arlstotelis, cum prsefatione densevis Istlus operis
Artstotelici, Helmstadt, 1715, 4to. Cf. Morhof, Polyhistorla, 2, 63. — TR.
4 Johannes Felden, a jurisconsult, lived during the seventeenth century.
Leibnitz refers to him in his Prelim. Dissert, to Nizolius (Gerhardt, 4, 155-
156: Erdmann, 67 b, 68 a: Dutens, 4, Pt. I., 57, 58), as the author of enuHth-
simse, . . . medltationes on the Topics and Analytics of Aristotle, "not yet
published," of notes on Grotius, of Elementa Juris universalis, and Analysis
Politicorum Arlstotelis. Cf., also, Mcrhof, Polyhistoria, 2, 559. —TR.
5 Johann Conrad Durrius, 1625-1677, was Professor of Theology and Moral
Philosophy at Altdorf. Among his writings were Compendium theoloyiu>
m.oralis, in several editions, one of the best being that of 1698, 4to ; Oratio
(idversiis Spinozam, Jena, 1672; Notve in Isayogen Piccarti, perhaps the work
Leibnitz here had in mind in referring to Durrius. Morhof, Polyhistoria, 2,
63, gives some account of an edition of Piccart's Ixagoye in lectionem Arlsto
telis, by Dnrrius, which appeared at Altdorf, 1665, 8vo. — TR.
APPENDIX 637
although each explanation, both of the Scholastics and of the
moderns, were possible, nevertheless from two possible hypotheses
must always be chosen the clearer and more intelligible, such as
indisputably is the hypothesis of the moderns, which makes for itself
no incorporeal entities in the midst of bodies, but besides magnitude,
figure, and motion assumes nothing. What possibility there is
of reconciliation I cannot better show than by asking that some
principle of Aristotle be given me which cannot be explained by
magnitude, figure, and motion.
Primary matter is the mass itself, in which there is nothing else
than extension and dimrvTua or impenetrability; it has extension
from the space which it fills; the nature itself of matter consists
in this, that it is something crass and impenetrable, and consequently
movable when another meets it (while the second must yield). Xow
this continuous mass filling the world, while all its parts are at rest, is
primary matter, from which all things are produced through motion,
and into which they are resolved through rest. For there is in
it no diversity, mere homogeneity, except through motion. Hence
already all the difficulties of the Scholastics are solved. First, they
inquire concerning its entitative character previous to all form. And
the reply must be that it is an entity previous to all form, since it has
its own existence. For all that exists, which is in any space, a fact
which cannot be denied of that entire mass although without motion
and discontinuity. But the essence of matter or the form itself of
corporeity consists in dvrtrvTria or impenetrability ; matter also has
quantity, but interminate, as the Averroists say, or indefinite ; for
while it is continuous, it is not cut into parts, and therefore no
termini are actually given in it: yet extension or quantity is given.
All things not concerning the extrinsic termini of the world, or
the entire mass, but concerning the intrinsic termini of the parts,
harmonize in a wonderful manner.
From matter let us pass to form through the dispositions. Here
again, if we assume form to be nothing else than figure, all things
wonderfully accord. For since figure is the terminus of body, to
introduce figures into matter there will be need of a terminus.
In order, therefore, that various termini may arise in matter, there
is need of a discontinuity of parts. For wrhile for this very reason
the parts are discontinuous, any one you please has separate termini
(for Aristotle defines continua d>y TO, co^aTa cv) ; but discontinuity can
be induced in that mass before continuous in two ways ; in one way
so that at the same time contiguity is destroyed, which happens
when they are so violently separated from one another that a
vacuum is left, or so that contiguity remains, which happens when
those which are immediate to themselves remain, yet are moved in
different directions; for example, two spheres, one of which includes
638 LEIBNITZ'S CRITIQUE OF LOCKE
the other, can be moved in different directions, and yet remain con
tiguous, although they cease to be continuous. From these con
siderations it is evident that, if indeed from the beginning a mass
discontinuous or broken up by vacuities was created, some forms
of matter are at once concrete ; but if, indeed, it is continuous from
the beginning, forms must of necessity arise through motion (for
concerning the annihilation of certain parts in order to obtain vacui
ties in matter, because it is beyond nature I do not speak, because
from motion division, from division termini of parts, from termini
of parts their figures, from figure forms, therefore from motion
forms arise). From which it is evident that all disposition to form
is motion, evident also the solution of the vexed question concern
ing the origin of forms. Which question the distinguished man
Herm. Conring could satisfactorily answer by his special disserta
tion only by asserting that forms arise from nothing.1 We shall
say they arise from the power of matter, not by producing any
thing new, but only by destroying the old, and causing termini by
division of the parts, as he who makes a column does nothing else
than 2 remove the useless parts, the residuum after the other parts
are removed by this very means receiving that figure which we call
a column ; that is to say, all the figures or forms which are contained
in the mass itself need only determination and actual separation
from the others adhering to them. If this explication is admitted,
whatever arguments are produced against the origin of forms from
the power of matter are mere trifles.
It now remains for us to come to changes. Changes are enum
erated commonly and rightly: generation, corruption, increase,
diminution, alteration, and local change or motion. The moderns
think all these can be explained through local motion alone. And
first, From increase and diminution the thing is manifest ; for a
change of quantity in the whole takes place when a part changes
its place, and either approaches or departs. It remains for us to
explain generation and corruption and alteration through motion,
and I note beforehand that the same numerical change is a gen
eration and alteration of different things, for example, since it is
evident that putrefaction consists in those worms imperceptible to
1 Gerhardt reads: " Conringius peculiar! dissertatione non aliter satisfacere
potuit, quam formas ex nihilo oriri." Erdmann reads: " Conringius peculiar*
dissertatione non aliter occurrit, quam concedendo formas ex nihilo oriri, sed
meditationes istae compendiosiorem viam monstrant, ut illuc confugere necesse
non sit. Discimus enim formas oriri, "etc.; i.e., Conring met in his special
dissertation not otherwise than by admitting that forms spring from nothing,
but these very meditations show a more advantageous way, so that it is not
necessary to flee thither. For we say that forms arise, etc.
2 Erdmann and Dutens read: " quam quod inutilia tollit," i.e., than that
which removes the useless parts. — TR.
APPENDIX 639
the naked eye, any putrid infection will be an alteration of the
man, a generation of the worm. In a similar way Hooke J shows
in his " Micrographia," that rust in iron is a minute little forest
(sylvulam) which has sprung up ; to rust therefore will be an alter
ation of the iron, a generation of little shrubs. But both genera
tion and corruption, as well as alteration, can be explained by a
minute motion of parts ; for example, since white is that which
reflects the most light, black that which reflects little, those things
will be white whose surface contains the largest number of little
specula; this is the reason why foaming water is white, because it
consists of innumerable little bubbles; moreover as many bubbles,
so many specula, since before well-nigh the entire water was nothing
but one speculum, as in a broken glass mirror (speculuni), so many
parts become so many mirrors (specula) : which, indeed, is the reason
why ground glass is whiter than that which is whole. In a simi
lar manner, therefore, when water is broken by bubbles into separate
specula, whiteness arises, which is the reason also why snow is
whiter than ice, and ice than water. For it is false that snow is
condensed water, since it is rarefied rather, whence also it is lighter
than water and occupies more space. By which reasoning the
sophism of Anaxagoras concerning black snow is explained (diluitur).
From these considerations it is evident that colors arise from change
alone of figure and position in the surface ; the same explanation as
regards light, heat, and all qualities, if occasion should allow, could
easily be given. But now, if qualities are changed through motion
alone, by the same process also substance will be changed : for if
all, nay even if some, of the necessary qualities are changed, the
thing itself is destroyed; for example, if you destroy either the
light or heat, you will destroy the fire. And if the motion is set
in operation (inhibito), you will produce each. And this is the
reason why a closed fire dies for want of the nourishing air, so
that I may pass over in silence the fact that the essence differs
1 Robert Hooke, 1635-1703, Professor of Geometry in Gresham College, Ox
ford, and Secretary of the Royal Society, published his Micrographia, or
some Physiological Descriptions of Minute Bodies in 1665. This book "con
tained the earliest investigation of the ' fantastical colours of ' thin plates,
with a quasi-explanation by interference, the first notice of the ' black spot '
in soap-bubbles, and a theory of light, as ' a very short vibrative motion '
transverse to straight lines of propagation through a 'homogeneous medium.'
Heat was defined as ' a property of a body arising from the motion or agita
tion of its parts.' " From his paper (May, 1666) on curvilinear motion, illus
trated with the aid of the "circular pendulum," showing experimentally that
the centre of gravity of the earth and moon is the point describing an ellipse
around the sun, dates " the clear statement of the planetary movements as a
problem in mechanics." For an account of his Vibration-theory, cf. Lasswit/,
Gesch. d. Atomistik, 2, 329-338. An abridgment of his Micrographia appeared
at London, 1780. — TR.
640 LEIBNITZ'S CRITIQUE OF LOCKE
from its own qualities only in relation to the sense. For as the
same city presents another aspect of itself, if you look down from
a tower in the midst of the city (in Grund gelegl), which is just
the same as if you beheld its essence ; it appears otherwise if
you approach from without, which is just the same as if you per
ceive the qualities of the body ; and as the external aspect of the
city varies, according as you depart from the eastern or the west
ern side, so in a similar way the qualities vary in proportion to the
variety of the organs. From these considerations now it is easily
manifest that all changes can be explained through motion. It is no
objection that generation takes place in an instant, that motion is
successive, for generation is not motion but the end of motion ;
therefore the end of motion is in an instant, for some figure is
produced or generated by the very last instant of motion, as the
circle is produced by the very last moment of the circumgyration.
From these considerations it is evident why the substantial form
consists in the indivisible, and does not receive more or less. For
figure also does not receive more or less. For although one circle
may be greater than another, yet the one circle is not more a circle
than the other, for the essence of the circle consists in the equality
of the lines drawn from the centre to the circumference : now
equality consists in the indivisible and does not receive more or
less. Nor, indeed, must the figure or the magnitude of the object
be accidents, nor in fact are they always accidents ; for although,
for example, flowing is an accident of lead, for it flows not unless
in the fire, it is nevertheless of the essence of mercury. Xo\v
the cause of flowing is without doubt the free curvilineity of
the parts, whether it consists of globes or cylinders or ovals or
other spheroids : the curvilineity therefore of the subtile parts is
an accident of the lead, but essential to the mercury. The reason
is, because all metals arise from fixed mercury by means of the
salts, and the nature of the salts consists in rectilinear figures fitted
for rest; hence, if we allow salts dissolved in water to crystallize
freely, some forms known to the chemists as tetraedric, others as
hexaedric, octaedric, etc., but none round or curvilinear, appear.
Hence salts are the cause of fixity; therefore those acid salts mixed
with the mercury in the bowels of the earth, as it were, through
the smallest parts impede the freedom of the curvilinear parts
by their interposition and constitute the metal. But in the fire
the metal returns to the nature of mercury, for the fire interposing
itself in the subtile parts, frees the curvilinear hydrargyrate parts
from the plane-sided salts; hence the flowing in the fire. Thus
it is evident that there is scarcely anything in the Aristotelian
physics which cannot be properly explained and illustrated by the
reformed.
APPENDIX 641
These examples, indeed, have occurred to me spontaneously (de
meo), while writing; very many more are collected by others through
all natural philosophy. Nor do I fear that in what I have hitherto
said, you will think that I have followed too much the descriptions
of R<eus or his authority. I was acquainted with such things
some time before I even heard of Rseus. I read Rasus, to be sure,
but in such a way that I now scarcely remember what subjects
he discussed. Nor, indeed, was R«us the first and only one of those
promoting a union between Aristotle and the moderns. Scaliger
seems to me to have been the first to pave the way; in our times
Kenelrn Digby and his follower, Thomas Anglus, the latter in his
book on the immortality of the soul, the former in his " Peripatetic
Institutions," treated ex professo the same subject long before Rseus.
Nor do both Abdias Trew l and especially Erhard Weigel differ
from them. Hitherto we have shown the possibility only of recon
ciliation ; it remains for us to show the necessity also. Of what
else, namely, does Aristotle in the eight books of the "Phys. Auditus "
treat than figure, magnitude, motion, place, time? If therefore the
nature of body in general is completed (absolvitur) by these, the
nature of body in particular will be completed by a given figure,
a given magnitude, etc. And, indeed, he himself says, Book o,
chapter (text.) 24, Phys., that all natural science is concerned with
magnitude (with which figure is connected), motion, and time.
Aristotle often says the same, that movable being is the subject of
physics, that natural science treats of matter and motion; he himself
also makes heaven the cause of all things which take place in the
sublunary worlds. Now heaven, he says, does not act upon the
bodies below it except through motion. But motion does not
produce anything but motion or termini of motion, namely magni
tude and figure, and from these the resulting position, distance,
number, etc. From these, therefore, everything in nature must be
explained. The same Aristotle likewise often says (as Book I.
of the "Phys. And.," chap. 69) that the relation of the brass to the
figure of the statue is the same as that of the matter to the form.
But 1 might prove that the figure is the substance, or rather that the
1 Abdias Trew, 1597-1669, was Professor of Physics and Astronomy in the
University of Altdorf, where he erected, 1657, the first observatory seen in
that part of the world. He made discoveries in the theory of music, espe
cially as regards the most accurate temperament, which he set forth iit his
Janitor lycsel /nitsici, Rothenburg, o. T., 1635. His chief work was in astron
omy and meteorology, and he carefully observed all the comets appearing
during his lifetime. As a chronologer he contributed to the adoption of the
Gregorian calendar by the Protestant states. He published, among other
works, Directoritnn mathematicum, Nuremberg, 1657; Lehrbuch d. sphiiri-
Kc.kcn Astronomic, Nuremberg, 1637; Griindliche Calendarkunst,l^nne\)eTg,
1660. — TK.
642 LEIBNITZ'S CRITIQUE OF LOCKE
space is the substance, that the figure is something substantial, because
all science is concerned with substance ; further it cannot be denied
that geometry is a science. You replied that you could produce the
place in which Aristotle had denied that geometry was a science
sooner than I would produce that in which he affirmed it. I do not
indeed doubt, illustrious sir, that there are some places of Aristotle
which can be drawn or twisted to this purpose, but yet I think that
these are overthrown by a very large number of his other expressions.
For what is more frequent in all the books of the "Analytics"
than examples of geometers, so that he seems to have wished
geometrical demonstrations to be, as it were, the measure of the rest.
Now the more ignoble is absurdly constituted the measure of the
more noble. And so meanly, indeed, did the Scholastics think of
mathematics at first, that they made every effort to exclude mathe
matics from the number of the perfect sciences, principally by means
of this argument, because it does not always demonstrate from causes.
But if we consider the matter more accurately, it will appear that
it does demonstrate from causes. For it demonstrates figures from
motion : from the motion of the point is produced the line, from the
motion of the line the surface, from the motion of the surface the
body. From the motion of the right line upon right lines arises
the rectangle. From the motion of a right line about an immovable
point arises the circle, etc. The constructions of figures, therefore,
are motions ; now from constructions relations (affectiones') con
cerning the figures are demonstrated. Therefore from motion, and
consequently a priori, and from cause. Geometry, therefore, is a true
science. Therefore with Aristotle's consent its subject, namely space,
will be a substance. Nor is it so very absurd that geometry treats
of the substantial form of bodies. For behold the passage of Aristotle,
13 "Met." chap. 3, in which he expressly says that geometry
abstracts from matter, from the final and the efficient cause; in
accordance with which supposition it follows that he treats either
of the substantial or accidental form. But he does not treat of the
accidental, because the accidental form in its own real definition
involves the subject or matter in which it is, although Aristotle
nevertheless says that geometry abstracts from matter. Therefore
geometry treats of the substantial form. Hence there immediately
arises in my mind as I write these things a certain beautiful harmony
of the sciences, the matter, of course, having been accurately con
sidered : theology or metaphysics treats of the efficient cause of things,
namely mind ; moral philosophy (whether practical or civil, for, as I
learned from you, it is one and the same science) treats of the final
cause of things, namely the good ; mathematics (I mean the pure, for
the rest is a part of physics) treats of the form or idea of things,
namely figure; physics treats of the matter of things, and of the
APPENDIX 643
single affection resulting from its combination with other causes,
namely motion. For the mind in order to obtain for itself a good
and pleasing figure and position of things, supplies motion to matter.
For matter by itself is devoid of motion. For the origin of all
motion is mind, as Aristotle also rightly saw.
For to come to this point, Aristotle seems nowhere to have pictured
to himself any such substantial forms, which are in themselves
the cause of motion in "bodies, as the Scholastics conceive; he
indeed defines nature as the origin of motion and rest, and form
and matter he calls nature, but form in a higher degree than matter,
but from this what the Scholastics mean (volunt) does not follow,
that form is a certain immaterial entity, irrational nevertheless in
bodies, which itself spontaneously without the impact of an external
thing gives motion downwards to a body, for example, to a stone.
For the form, indeed, is a cause and source of motion, but not at
first. For a body is not moved, except from the outside, as Aristotle
rightly not only says, but also demonstrates ; for example, a globe
may be in a plane, if it is once at rest it will not move of itself
forever, unless in consequence of an added external impulsor, for
example, another body. If this now approaches, the second body is
the. source of the impressed motion, but the figure,, namely globosity,
is the source of the motion taken up, for if globosity were absent,
having been produced by chance according to circumstances, the
body wTould not yield to the second body so easily. From this it
is evident that the scholastic concept does not follow from the defi
nition of the Aristotelian form. Form, therefore, is the source of
motion in its own body, and body itself is the source of motion in
another body, 1 confess ; but the primary source of motion is the
primary and in reality from matter abstracted form (which at the
same time is efficient), namely mind. Hence liberty and spontaneity
occur in minds alone. Therefore it is not absurd that of the substan
tial forms mind only is called the primary source of motion, the
others having their motion from mind. And by this argument he1
ascends to the first mover. To this objection you give a twofold
reply ; first, this argument can avail nothing with Epicurus, who
bestows upon his atoms per *e downward motion. I admit that this
argument can avail nothing with him, unless it be previously demon
strated to him that this itself is absurd and impossible, namely, that
a body has motion from its own self, a thing which Cicero also if
I am not mistaken already at that time did in his books " De natura
Deorum," gracefully laughing at Epicurus because he introduced
in this way something without cause and reason in his hypotheses.
For in the nature of things nothing is down save as regards us,
1 Aristotle. — Gerhard? s Note. — TR.
644 LEIBNITZ'S CRITIQUE OF LOCKE
and so there is 110 reason why any body should move in this
rather than in that direction (plagam). Therefore we shall easily
answer Epicurus, denying that whatever is moved is moved by
another outside itself, and shall vindicate the laboring certaintv of
the existence of God. Second, you object that Aristotle seems to
have reasoned not so much from this axiom that the source of all
motion is outside the moved body, as from the other th,at progress
into infinity is not granted. But in truth, most noble sir, consider
carefully whether or not either connection of ideas is needed.
For unless it is admitted that what is moved extraneously is moved,
plainly we shall arrive at 110 progress, still less at infinity ; for the
opponent will resist steadfastly from the beginning and any given
body will reply that it is itself sufficient to produce its own motion
through its own substantial form, and needs therefore no mover,
much less the first. Therefore that ladder will tumble down as
soon as the first step, and as it were the foundation, is taken away.
Then also Epicurus was wont to admit progress into infinity ; there
fore we must consider not so much what Epicurus admits or does
not admit, as what can certainly be demonstrated. The Aristotelian
philosophy, the inevitable result of the reformed philosophy itself,
must be briefly touched upon.1 It is plain that what must be dis
cussed by the theologians must be discussed by the philosophers
also. The holy fathers illustrated the Holy Scripture by the best
interpretations : soon the monks obscured them by superstitions.
The light of souls having arisen, the reformed theology is three
fold : the one heretical, which rejects the scriptures themselves, as
of the fanatics; the second schismatical, which harmonizes the an
cient fathers, the doctors of the church, with the sacred scripture
and the primitive church, as of the Evangelicals.2 In like manner
the Greek interpreters3 illustrated Aristotle, the Scholastics obscured
1 The Latin text, reads: " Aristotelicam philosophiam reformatse ipsius
philosophise inevitabilis eventus breviter attingenda est." Gerhardt's note
reads : " In diesem Satze fehlt etwas," i.e. In this sentence something is want
ing- Erdmann gives the following: "Observ. Thomasii. Sic scriptum erat a
librario, sed hiat alias haec periodus: nee lectionem ejus constituo," i.e. Note
of Thomasius. Thus it was written by the copyist, but this sentence is other
wise lacking: I do not determine its reading. — TR.
2 Gerhardt's note reads: " Auch hier scheint etwas zu fehlen," I.e. Here
also something appears to be wanting. Erdmann gives the following : ' ' Observ.
Thomasii. Etiam hie aliquid deest ; datur enim pro triplici theologia tantum
duplex. Scripsisse puto: alia schismatica, alia vera, quae priscos Patres, etc.
Confer sequentem," i.e. Note of Thomasius. Here also something is wanting ;
for, instead of the threefold theology, only a twofold is given. I think he wrote :
the second schismatic, the third true, which the ancient Fathers, etc. Cf. the
following. — TR.
3 Gerhardt reads, " interpret es " ; Erdmann, " Patres." — TK.
APPENDIX 645
him with trifles. The light having arisen, the reformed philosophy
is threefold : the first stupid, like that of .Paracelsus,1 Helmont,2 and
of the others who utterly reject Aristotle ; the second bold, which
with small regard for the ancients, nay with open contempt for
them, render(s)3 (their) its own meditations even when good sus
pected, such as that of Descartes; the third true, by whom Aristotle
is recognized as a great man and in most things right.
The reformed philosophy having just been reconciled with Aris
totle, it now remains to show its truth per se, precisely as the Chris
tian religion can be proved both from reason and history and from
the sacred Scripture. But it must be proved that no entities are
given in the world besides mind, space, matter, motion. Mind I call
thinking being. Space is a primarily extended entity or mathemati
cal body, which manifestly contains nothing else than three dimen
sions, and is also that universal place of all things. Matter is a
secondarily extended entity, or that which besides extension or math
ematical body has also physical body, that is, resistance, avTirviriav,
density, the power of filling (repletivitatem) space, impenetrability,
which consists in this, that it is compelled by the approach of another
such being to move or to stop the other ; from wrhich nature of im
penetrability therefore motion flows. Matter therefore is an entity
which is in space or an entity coextensive with space. Motion is a
change of space. But figure, magnitude, position, number, etc., are
not entities really distinct from space, matter, and motion, but only
conditions (habitudines) amid space, matter, motion, and their parts
made by the supervenient mind. I define figure further as the ter
minus of extension, magnitude as the number of parts in the exten
sion. I define number as one, and one, and one, etc., or unities.
Position is reduced to figure, for it is a formation (confgu ratio) of
many (figures). Time is nothing else than magnitude of motion.
And since every magnitude is a number of parts, what wonder
Aristotle defined time as the number of motion ? But thus far ter
mini only have been explained, and the sense in which we use them
set forth, but nothing as yet proved. Now let us show that there is
no need of any other things in order to explain the phenomena of the
i Theophrastus Paracelsus, 1473-1541. On his philosophy, cf. Stockl, Gesch.
<L Philos.d. Mittelalters, III. [Vol.4], 430-452; Lasswitz, Gesch. d. Atomistik,
1, 2!)8-SO<;. — TR.
- Joh. Bapt. Van Helmont, 1577-l(i44. On his philosophy, cf. Stockl, Gesch.
d. PhWm. d. Mtttelalters, III. [Vol. 4], 458-472; Lasswitz, Gesch. d. Atomistik,
1, :!4:;-:«l. -TR.
3 The Latin text reads, " suas suspectas reddunt," as though the writer had
in mind those holding the view rather than the view itself with which the
sentence began, and in consistency with which beginning the verb should
have been " reddit." — Tu.
646 LEIBNITZ'S CRITIQUE OF LOCKE
world and to assign their causes, nay, also that there can be no other
things, although if we show that there is no need of other things
besides mind, matter, space, and motion, by this very thing it will
be shown that the hypotheses of the moderns who employ these
things alone in the assignment of phenomena are the better. For it
is a defect in an hypothesis to assume unnecessary things. Now that
all things in the entire world can indeed be explained from these
alone, the reading of the modern philosophers sufficiently teaches, and
it is evident from the considerations which I put down a little before
when I was showing the possibility of an Aristotelic harmony. Then
it must also be noted that these hypotheses are the better which are
the clearer. Now, indeed, the human mind can imagine nothing else
than mind (when, namely, it thinks of itself), space, matter, motion,
and what results from these when united with each other ; whatever
else you add are words only, which can be named and variously
combined with each other, but cannot be explained and understood.
For who can imagine to himself a being which partakes of neither ex
tension nor thought? What need therefore to posit souls of animals
and plants, the incorporeal forms of the elements, the substantial
forms of the metals, devoid of extension ? More correctly there
fore Campanella 1 in his book "De Sensu rerum et Magia," and Marcus
Marci,'2 " De Ideis operatricibus," falsely indeed, yet in agreement
nevertheless with their hypotheses, attributed to these substantial
forms of inanimate things, deprived of extension, sense, knowledge,
imagination, will. Nor is the occult philosophy of Agrippa,3 who adds
an Angel as it were an obstetrician to everything, unlike it, nor the
discussions of Scaliger Trept 8wa/Ae<D? TrAaortK^s and its intelligence.
Thus it returns to as many little gods (deunculos} as substantial
forms, and to a race almost 7roAv^ei'o-/xoi/. For hence is attributed to
them appetite, and the natural instinct from which also follows
natural cognition, hence these axioms : Nature does nothing in vain,
everything shuns its own destruction, like takes pleasure in like,
matter desires a nobler form, and others of this description, since
nevertheless there is, in truth, in nature no wisdom, no appetite, but
a beautiful Order springs out of it, because it is the clock of God.
From these considerations it is evident that the hypotheses of the
reformed philosophy are superior to the scholastic hypotheses for this
1 Tommaso Campanella, 1568-1639. Brief account of his views is given
in Lasswitz, Gesch. d. Atomistik, 1, 340-343. Cf., also, Stock], Gesch. d.
Philos. d. Mittelalters, III. [Vol. 4], 343-366. — TR.'
2 Cf. infra, p. 670, n. 2. — TR.
3 Heinrich Cornelius Agrippa von Nettesheim, 1486-1535. His Opera omnia,
Lugduni, 1600; the De occulta philosophia in Vol. 1. For an account of his
views, qf. Stockl, Gesch. d. Philos. d. Mittelalters, III. [Vol. 4], 412-420;
Lasswitz, Gesch. d. Atomistik, I, 290-293. — TR.
APPENDIX 647
reason, because they are not superfluous, while, on the other hand, they
are clear.
It remains for us to prove by more subtle reasoning that other
entities than those I have mentioned cannot indeed be assumed
in explaining the nature of bodies. It will be done thus: All call
that body which is endowed with some sensible quality, then out
of the sensible qualities many can be taken away, provided never
theless that the body remains. For although a body is deprived of
all color, odor, taste, yet it is called a body. For you will grant
that air, for example, is a body, although it is transparent, and
so not colored, besides it is devoid of taste, and for the most part also
of both odor and sound. Therefore the qualities visible, audible, and
those of taste and smell, may be cast aside as least constitutive
of the nature of body. To tactile qualities, therefore, everything
returns. And indeed these primary qualities — heat, moisture, dry-
ness, cold — can each be absent ; heat can be absent from \vater,
moisture from the earth, dryness from the air, cold from the fire, and
yet any of these is a body. The other tactile qualities — for example,
smoothness, lightness, tenacity, etc., are acknowledged even by you
not to belong to the constitutive nature of a body, for this very
reason, because they are called secondary, and so have arisen from
others, and further because there is no one of them which cannot be
absent from a body. There remains, therefore, to be sought for some
sensible quality which is competent to all and single bodies and from
which as it were by a sign men may distinguish body from non-body.
This without doubt is density (crassities), or avrtrvTrta, taken with
extension. Whatever men certainly think extension is (although
in truth it always is body and has avTirvTrta, although insensible
to us, yet perceptible by the intellect), they do riot at once call that
body, for they sometimes think that it is a mere appearance and
^avraarfia. But whatever they not only see but also touch, that is, in
which they find dmrvTua, that they call body ; but whatever lacks
dvTiTVTria, that they deny to be body. In the two, therefore, men
both educated and uneducated place the nature of body, in extension
and dvTiTUTTia taken together ; they take that from sight, this from .
touch ; whence also from the union of both senses we are wont to be
certified concerning things that they are not phantasmata. But
extension is nothing else than existence in space; avTurvTrta is the
inability to exist with another in the same space, but the one or the
other (alterutrum) must be moved or keep quiet. From these con
siderations it is evident that the nature of body is constituted by
extension and antitypy, and since there is nothing in things without
cause, nothing even must be assumed in bodies, the cause of which
cannot be made to appear from their primary constitutive principles.
Now the cause cannot be made to appear from these except through
648 LEIBNITZ'S CRITIQUE OF LOCKE
their definitions. Nothing, therefore, is to be assumed in bodies
which does not flow from the definition of extension and antitypy.
But there flow from this definition only magnitude, figure, position,
number, mobility, etc. Motion itself does not flow from these. AVhence,
properly speaking, motion is not given in bodies as a real entity
in them, but I have demonstrated that whatever moves is continually
created, that bodies at any instant in assignable motion are some
thing, at any intervening time between the instants in assignable
motion are nothing, a thing which was unheard of till now, but
which is plainly necessary and will shut the mouth of the atheists.
From these considerations it is evident that the explanation of all
qualities and changes must be taken from magnitude, figure, motion.,
etc., and that heat, color, etc., are nothing but subtile motions and
figures. As to what remains, I dare affirm that atheists, socinians,
naturalists, sceptics, would never have been truly met unless by this
established philosophy ; which I indeed believe a gift of God given
to the old age of the world as an unique plank by which pious and
prudent men are about to save themselves in the shipwreck of the
now overhanging atheism. However small my knowledge of learned
men after a little time, I nevertheless tremble as often as I think how
many men at the same time intellectual and absolutely atheistic
I have met. And there is flying through the hands of men an
unknown book of Bodin l (and would, as I wish in the case of
Naud;ieus, it was never to be published), powerful certainly, which he
calls. " Arcana sublimium," in which he is the professed enemy
of the Christian religion. The dialogues of Vaninus '2 are child's play
when compared with it. I have read it carefully, and I thank God
from my heart, because he furnished me with those defences of
1 Jean Bodin, 1530-1596 or 1597, the eminent writer on Political Science,
and advocate of tolerance in religion, published his greatest work, — "the first
elaborate attempt in modern times to construct a system of political science,"
— Les six Livres de la Republique, at Paris, 1576. His Universes naturse
theatrum appeared at Hanover, 1605, the Preface dated February 25, 15%.
For some account of its doctrine, cf. Lasswitz, Gesch. d. Atomistik, 1, 326-
.'527, 411-413. G. E. Guhrauer published an Abstract, in German, with a
partial translation of the Latin text, of his very famous MS., here referred to
by Leibnitz, the Colloquium heptaplomeres de abditis rerum sublimium arca-
nis, Berlin, 1841, and the complete original text, from a MS. in the Giessen
Library, was edited and published by L. Noack, Schwerin, 1857. The work is
''a conversation between seven learned men, — a Jew, a Mahometan, a
Lutheran, a Zwinglian, a Roman Catholic, an Epicurean, and a Theist " :
and "the conclusion to which they are represented as coming is, that they
will live together in charity and toleration and cease from further disputa
tions as to religion." — TR.
-Lucilio Vanini, 1585-1(519, who called himself by the name, among others,
of Julius Cffisar, was a disciple of Pomponatius (cf. ante, p. 581, n. 1). He
denied the immortality of the soul, and advocated a doctrine of pantheistic
APPENDIX 649
philosophy (in which 1 should be ungrateful, if I should deny that
1 owed much to you), by which 1 repelled his weapons with no
difficulty. The labor of the distinguished Spizel is to be praised,
which he now again expends in eradicating atheism. His letter
on this subject, recently published (in these nine days), I think you
have seen. Hear what happened to me in connection with him.
I had written some time when at leisure, a leisure nevertheless
disturbed in the inn, about two sheets, in which I was discussing
the demonstration more accurately than usual of the immortality
of the soul and the existence of (iod. These I had sent to my
friend. Through him they came into the hands of the Most Rev
erend Spener,1 pastor at Frankfort, a neglected yet deserving author.
Spener sent them to Spizel ; 2 Spizel placed them at the end of
that recent letter of his to Ant. Reiser 3 on the eradication of
atheism, under the title " Confessio naturae contra atheistas." I
do not blame him, but I am grieved, because that cr^eStoy was
so very incorrectly printed ; that sorites, especially, by which I tried
to demonstrate the immortality of the soul, was thrown into strange
confusion by the misplacing of its opening lines. Spizel acknowl
edged that he was ignorant of the author. I desire a judgment
naturalism. He published Be admirandis naturse reginss deseque mortaliunt.
<tt'canif>, lib. quat., Paris, 1616. His philosophical works, translated into
French by Rousselot, appeared at Paris, 1841. Leibnitz, in a letter to Sebas
tian Kortholt, March 15, 1713, says: " Apologiam Vannini nondum vidi, nee
magnopere dignani legi puto. Scripta ejus parvi momenti sunt, sed homo
ineptus, imo stultus comburi non merebatur, claudi jure poterat, ne alios
inficeret" (Dutens, 5, 321).— TR.
1 Philip Jacob Spener, 1635-1705, was chief pastor of the Lutheran church
at Frankfort-on-the-Main, from 1666-1686, first Court-chaplain at Dresden.
1686-1691, and rector of St. Nicolas, in Berlin, with the title of " Consistorial-
rath," from 1691. He directed the foundation of the University of Halle in
1691. Though, according to Ritschl, Gesch. d. Pietismus, 2, 163, Bonn, 1884.
" himself not a Pietist," Spener has justly been called "the father of Pietism."
He was a voluminous author. Two letters of Leibnitz to Spener are given by
Dutens, 5, 467-468. — TR.
2 Theophil Gottlieb Spitzel, or Spizel, 1639-1691, a German pastor and poly-
historian, was deacon of St. James's church, Augsburg, in 1662 and pastor from
1682 to 1690. " As a theologian, in spite of his many-sided and universal sci
entific interests, he remained well-nigh unfruitful." Leibnitz refers to the
matter here alluded to again in his letter to Spizel, December 12-22, 1669; cf.
Dutens, 5, 343. The Confessio Naturx contra Atheistas first appeared as a
Postscriptum in Theo. Spizelii de Atheismo eradicando ad Virum pnestantis-
simum Dr. Antonium Reiserurn Auf/ustanum, etc., Epistola. . . . August.
Vindel. 1669.— TR.
:{ Anton Reiser, 1628-1686. a learned and distinguished Lutheran theologian,
was an earnest defender of evangelical truth. He published De origine, pro-
f/ressi( ct incremento antitheismi sen Atheismi. Augsburg, 1669, 8vo; Index
3/.V.V. bibliothectc AuguKtame, Augsburg, 1675, 4to. — TR.
650 LEIBNITZ'S CRITIQUE OF LOCKE
concerning the reasoning itself of the demonstration. Xor do I
seek praise, but criticism, since it is important to religion that it
be not perfunctorily defended. Although meanwhile T seem to
myself to have penetrated far more deeply into both. For .neither
the thoughts which T have thrown out since that time concerning
perpetual creation in motion, nor the inmost nature of thinking
being or mind, are brought together therein. I wrote you at one
time about the society which certain Germans are starting. It
will show its existence by a German paper published by the book
seller Goezius with the title " Collegium Philadelphicum." But to
me it seems a pleasant dream, like the society of the Red Cross.
It is wonderful how great a dissension in Parnassus that Schurx-
fleisch 1 who is with you excited. I very much wish to know what
the great men with you by whom he hopes he will be advanced,
think of this specimen. Boeder2 threatens that one from the court.
The author of the " Itinerarium politicurn " which is now appearing
is without doubt Burgoldensis,3 that commentator on the "Instru-
mentum pacis." I am astounded at the audacity of the man.
As for the rest, most illustrious sir, I have discoursed the more
1 Konrad Samuel Schurtzfleisch, 1641-1708, was Professor of History at
Wittenberg, and because of his great learning was given the nickname of a
living library and a walking museum. While at Wittenberg he published,
under the name of Eubulus Theosdatus Sarckmasius, a pamphlet, Judicia de
novissimis prudentise civilis Scriptoribus, Leipzig, 1(569, in which he freely ex
pressed his opinion of the most celebrated German jurisconsults, and which
aroused against him many adversaries. He continued the history of Sleidan
(cf. ante, p. 114, n. 1). — TR.
2 Johann Heinrich Boeder, 1611-1692, Professor of Eloquence at Strassburg
and Upsala, and afterwards of History at Strassburg, was author of many
commentaries on classical authors and of works of history, politics, criticism,
morals, etc. Among them were : De jure Gallise, in Lotharingiam, Strass
burg, 1663; Ad Grotium de jure belli et pacis dissert., V., 1665. The Elector
of Mayence appointed him " conseiller " in 1662, and the next year the Em
peror Ferdinand III. bestowed on him the same title and made him Count
Palatine.— TR.
3 Philippus Andrea Oldenburgerus, the anagram of which is Burgoldensis,
a pupil of H. Conring, was Professor of Law and History at Geneva, where he
died in 1678. He published a large number of valuable works, some of them
under assumed names, among which are: Itinerarium Germanise Politicum,
rnodernain prsecipuarum Aularum Imperil faciem reprsese ntans , Cosmopoli
(Geneva), 1668, 12mo; Limn&us enucleatus, an abstract of Limne, De jure
imperil Romano-germanici, Geneva, 1670, fol. ; Notitia Imperil, sive Discur-
xus in Instrumentum Pads Osnabrugo-Monasteriensis (this work under the
name of Burgoldensis), Freistadt, 1669, 4to. Of the Itinerarium Germanic
Politicuiii, Morhof, Polyhistoria, 2, 497, says: " in quo multa est rerum inep-
tissimarum farrago, quibus nonnunquam immiscentur aliqua uotatu non in-
digna, sed lectore prudente opus est, qui cum judicio ilia legere posit." The
freedom with which the author spoke of the political interests and vices of the
German courts led to the interdiction of his book. It was, nevertheless,
APPENDIX 651
at length of this whole matter to you for this reason, because I
had no more learned and equitable judge of these things. Since
you have examined all the recesses of the ancients and do not
despise the discoveries of the moderns when deserving, you alone
of all can best examine this and also illustrate them. For you
rightly judge, that although new opinions are brought forth and
their truth most evidently shown, yet from the views publicly
received we must scarcely ever depart, a thing which we should not
strive for if the Scholastics had done it. Farewell, ornament of
our country, and do not bring to an end (absolve) your noble thoughts
(for many are both begun and at the same time perfected with rare
felicity of mind), but produce them.
II
FRAGMENT L
[From (he Latin]
The primary matter 2 of Aristotle is identical with the subtile matter
of Descartes. Each is divisible to infinity. Each is per se lacking in
form and motion, and each receives forms through motion. Each
receives motion from mind. Each is formed into certain rings (gyros),
and there is no more solidity in the vortices of Aristotle than of
Descartes. Each has solidity from motion, because nothing drives
it asunder, although Descartes himself has not assigned this cause
of solidity. Each ring (gyrus) extends (propagat) the action im
pressed through motion on account of the continuity of matter into
another ring. For Aristotle also, no less than Descartes or Hobbes,
derives all particulars from the motion alone of universal rings*
Whence Aristotle adds intelligences only to the principal rings,
because from the impacts of these rings the actions of the others
follow. In this Aristotle erred, because he made the earth the
centre of the universe and of all gyrations. But he should be par-
several times reprinted. In Pt. IV. of his Thesaurus rerum publicarum totius
orbis, Geneva, 1675, 4 vols., 8vo, he repudiated the errors and condemned the
reprehensible expressions which he had employed in the earlier work. Of the
Discursus in Instrument urn Pads, Lenglet du Fresnoy remarks : "a bold and
learned piece." — TR.
1 Gerhardt, Leibniz, philos. Schrift., 7, 259-60. In his Einleitung, ibid.,2ol,
G. says: " The fragment, n. I., which was written, perhaps, at the time of the
composition of the Hypothesis phyxica (1(571), contains a comparison of the
metaphysics of Aristotle and Descartes, what Leibnitz borrowed from both,
and what he has added of his own." — TR.
2 Upon a bit of paper without date and superscription, proceeding according
to the handwriting from the earliest period. — Gerhardt's Note. — TR.
652 LEIBNITZ'S CRITIQUE OF LOCKE
doned for this, because philosophy was not yet sufficiently instructed
by observations.
To these I now add, that primary matter if at rest is nothing. This
also is a statement w?hich certain Scholastics have obscurely made,
that primary matter also has existence from form. Of this fact
there is demonstration. Because whatever does not think, is nothing.
But that in which there is no variety also does not think. In
like manner : Tf primary matter moves in one direction, that is,
in parallel lines, it is at rest, and consequently is nothing. All
things are full, because primary matter and space is the same thing.
Therefore erery motion is circular, either composed of circulars or
at least returning into itself. Many circulations mutually hinder
each other, or mutually lead into each other. Many circulation* try
to unite in one or all bodies tend to rest, that is, annihilation. //
bodies are without mind, it is impossible for motion to have been eternal. l
From universal conflicting circulations are produced particular bodies.
Matter is actually divided into infinite parts. There are infinite creatures
in any given body whatever. All bodies cohere among themselves. All are
indeed forcibly separated (distrahuntur) from all, but not without resist
ance. There are no atoms, or bodies whose parts are never forcibly
separated. There are two principles by \vhich motion is changed :
compositions of efforts (conatuum), and compositions ... [a word
and two lines are in consequence of the destruction of the paper
illegible. — GERHARDT].
Ill
DEMONSTRATION AGAINST ATOMS TAKEN FROM
THE CONTACT OF ATOMS2
October 23, 1690
[From the Latin]
DEFINITION I. A thing is distinguished from other things in two
ways, either through itself, or extrinsically. Through itself a thing is
distinguished from another, when a method of distinguishing through
the consideration alone of the thing is used, no operation or change
being made in the thing. Extrinsically, when by external application
something new is produced in the thing, which does not appear in
1 Over the words, " motum fuisse aeternum,'' Leibnitz has written, " potest
diminui sine fine," i.e. can be diminished without end. — Ge/'hardt's Note. — TR.
- Gerhardt, Leibniz, philos. Schrift., 7, 284-288; Stein, Leibniz, u. Spinoza,
XIV.. pp. 325-328. — TR.
APPENDIX 653
another. Thus the sphere and the cube can be distinguished both
by consideration and also by operation ; by consideration, because in
the sphere no angles are found, of which there are eight in the cube ;
by operation, as, if both are placed upon an inclined plane, the sphere
will descend the plane by rolling, the cube by sliding.
AXIOM. Whatever is distinguishable extrinsical ly from another, is
also distinguishable through itself.1
For example, let there be two coins from the same stamp (typo), one
of true gold, the other of false, which may be easily distinguished
extrinsically by the blow of the hammer. I say even before the
blow, by an attentive consideration, differences in the composition
itself of each would be detected by the naked or equipped eye, and
although the keenness of vision could not reach thither, yet differ
ences exist within and can be detected by some more acute creature
(for example, by an angel).2
OBSERVATION. Certain bodies are mutually separated violently
from each other.
CONCEDED HYPOTHESIS. Matter is uniform, or, motion and figure
excepted, everywhere like itself.
DEFINITION II. An Atom is a body which cannot be broken.
POSTULATE. If there are atoms, we may assume them of any figure
and si/e whatever and in any position whatever.
THEOREM.
// in imjjoxxible for all bodies to consist of atoms.
Let us assume (by the postul.) three atoms, A, B, C, of which A is
cubical, but B and C are triangular prisms, composing the cube D,
similar and equal to the former A. The cube D cannot (by the
conceded hypothesis) be distinguished from the cube .4. Therefore
they cannot be distinguished extrinsically (by Axiom I.). If there
fore other bodies strike against the cube D. they will be able either
to separate the atoms B and C, or they will not be able. If able to
separate them, then the same bodies striking in the same way against
1 On the margin of the Ms.. Leibnitz has remarked : " Whatever is dis
tinguishable in itself, is also distinguishable extrinsically. If two bodies are
similar through a third similar body, they cannot be distinguished. If two
bodies are similar, but mutually unequal per xe, they can be distinguished,
no third body even being assumed. Similar and equal bodies cannot be dis
tinguished extrinsically, nay, rather, in any Avay, and so are one and the same."
— Gerhard t.' if Note. — TR.
2 Stein here inserts in his text the following marginal gloss, wanting in
(•ierhardt's text : "Hie ostenditur ex hypothesi Atomistioa sequi, quod novae
Atomi nasci possint, nee tamen iterum dissolvi contra naturae morem," i.e.
Here it is shown to follow from the Atomistic hypothesis, that new atoms can
be produced, but nevertheless cannot again be dissolved contrary to the law
of nature. — TR.
654
LEIBNITZ'S CRITIQUE OF LOCKE
the cube A will be able violently to separate the same into parts, for
otherwise A and B might be distinguished extrinsically (by Defin. I.),
the contrary of which has been shown. But if the cube A is vio
lently separated into parts, it certainly (by Defin. II.) will not be an
atom, as was supposed. But if other bodies cannot again separate
the cube D into component parts, it follows that the atom was not
B
FIG. 1.
produced from non-atoms through contact. And the same principle
will hold, whatever figure the atoms be assigned. Whence it follows
that atoms which have once touched each other cannot again be
violently separated. Now if all bodies are composed of atoms, bodies
do not touch each other except through the atoms. Therefore they
cannot be violently separated after contact, unless the atom of the
one is violently separated from the atom of the other, which we
have shown cannot be done. But bodies not be violently sepa
rated. . . . l And so it is not true that all bodies are composed of
atoms. Q. E. D.
SCHOLIUM TO THE DEMONSTRATION AGAINST ATOMS TAKEN
FROM THE CONTACT OF ATOMS.
October 24, 1G90.
I do not see what reply can be made to this demonstration unless
by a denial of the postulate. For we postulated that it be conceded
us : If there are atoms, they can be assumed of any figure and size
and in any position whatever. This alone seems possible to be said with
any reason, atoms cannot be granted, the parts of which are connected
only by a point or line. And so there cannot (for example) be an
1 More words illegible. — Gerhardt't
sentence. — TR.
Note. Stein omits this incomplete
APPENDIX 665
atom similar to one composed from two spheres touching each other.
But if then atoms spherical or terminated by any other curved sur
faces whatever are granted, they never touch each other save in a
point, and so never compose a body similar to an atom. Here in
some way I think a reply can be made, in the first place if the contact
in the surface is the cause of stability, it follows that stability is
greater when the surface is greater. Whence the atoms would not
be equally stable. And so there would be a certain determinate
force of violent separation by which stabilities could be measured.
I do not see where we can find this force, if it is not in the motion of
bodies, unless we advocate certain spiritual powers whose method of
acting in bodies nevertheless cannot be known. But if the stability
of all atoms is equal, it does not matter how great the contact is ;
even contact in a line, nay in a point, would suffice.
A second reply which can be made is this : it has at least been
demonstrated by us that bodies cannot be composed of atoms ter
minated by plane sides. But besides the fact which can be doubted,
whether indeed curvilinears properly called are granted, this excep
tion does not seem in agreement with the reasons of things, that if
composition from atoms is possible it must necessarily take place
through bodies destitute of a plane surface.
The third reply is this : not only the atoms of plane surfaces but
also of concave must be assumed (tollendas} from nature. Otherwise
we shall be permitted to make atoms from the non-atom, as often as
the concave surface of one atom happens to be applied to the convex
surface of another, and that will happen until all the atoms of the
concave surfaces shall be filled as far as can be done by the convex
existing in nature. But this restriction also does not seem in har
mony with the reasons of things. And in general, if any one denies
that there are other atoms than the perfectly spherical, in order to
escape the force of the demonstration, these things are devised which
indeed are accommodated to the latter, but do not accord with the
primal reasons and amplitude of nature. In brief : from the hypo
thesis of atoms I can deduce absurdity, provided I am allowed to
assign to the atoms size, figure, and motion as 1 will.1
1 On the margin of the Ms., Leibnitz has remarked: "Another argument
could be set up, namely : If atoms could be granted, bodies similar and equal,
and nevertheless different from each other, as would be two equal spheres,
could be granted. If atoms were granted, no cause of reflection, which in fact
must be taken from an elastic body (Elaterio), could be perceived, nor would
the atoms striking each other leap apart, in turn, from each other. Further
superficial contact is the cause of cohesion, two atoms coming together in
sides or surfaces would not leap apart ; thus, if the velocity of each approach
is equal, the whole force would perish." — GerharcU's Note. Stein has put this
marginal gloss into the text, with a note stating that it is a marginal gloss.
-TR.
656 LEIBNITZ'S CRITIQUE OF LOCKE
APPENDIX TO THE DEMONSTRATION AGAINST ATOMS TAKEN
FROM THE CONTACT OF ATOMS.
If any one denies that there can be atoms, the parts of which touch
each other in a point only or line, and so requires contact in the sur
face for cohesion, that he may avoid the force of our demonstration,
that one will entangle himself in other new difficulties.
For if cohesion arises from superficial contact, a case can be seen
in which an atom is unable to graze (radere) an atom ; for where a
part of the side of the atom B coincides with a
A o A i A part of the side of the atom AA , they are not
only unable to leap apart and also to separate
violently, but even the one will not be able to
slide upon the other, for they touch each other
in the surface. Nay, rather, what is more
pIG 2. wonderful, the atom A coming by its own mo
tion from the place ^ into the place 2/l so
situated, that it is unable to proceed farther, because it grazes the
atom B, is there arrested without any obstacle as if it were an en
chanted object. Nor does it suffice to say that no such atoms are
given, and that no others exist unless spherical or at least bounded
by convex surfaces. For it suffices that atoms bounded by plain or
concave sides are possible, if those bounded by convex sides are
possible; and from the supposed possibility of these that which is
absurd follows, whence it follows that convex atoms .are not to be
admitted.
But if any one because of these considerations now requires no
longer superficial contact only, but also the rest of bodies tangent to
each other for cohesion, lest forsooth one atom be kept from sliding
upon another, that one is unable to bring forth proof of his opinion,
nor does it appear why the nature and the force of the present state
which is contact must depend upon a past state, so that forsooth the
present contact causes cohesion, if it has remained for some consider
able time in the same place, as if there were need of a certain habi
tude, whence indeed it would follow that stability is increased by
duration and that atoms newly produced are the more stable the
longer they cohere, a fact which no one will surely easily affirm. But
neither can the moment be assigned in which the cohesion of two
atoms begins, because it is entirely perfect at once. And if it does
not begin unless it has continued for some' time, it will never begin,
for it would itself be prior to itself. Moreover, all rest can be under
stood as composed of two motions, so that if a body is moved at the
same time by two moving bodies and so remains quiet accidentally,
shall it then be understood also to adhere to the sides of another body
APPENDIX 657;
which it grazes ? And so whithersoever we are turned, we fall, into
aTropa, which is not strange, because we assumed an hypothesis lack
ing in reason, namely, that the highest stability is without an intelli
gible cause.
But if any one thinks that atoms can be produced at least by the
decree of God, we confess to him that God can make atoms, but a
perpetual miracle would be needed to resist a forcible separation,
since in a body itself a principle of perfect stability cannot be per
ceived. God can perform whatever is possible, but it is not always
possible to transfer his power to creatures, and to bring it to pass
that they themselves can do per se what they accomplish through his
own power alone.
IV
ESSAY ON DYNAMICS ON THE LAWS OF MOTION, IN
WHICH IT IS SHOWN THAT NOT THE SAME QUAN
TITY OF MOTION IS PRESERVED, BUT THE SAME
ABSOLUTE FORCE, OR RATHER THE SAME QUANTITY
OF MOVING ACTION (L' ACTION AfOTRlCE)**
%.
[From the French]
The opinion that the same quantity of motion is preserved and
abides in the concourse of bodies has reigned a long time, and passed
as an incontestable axiom among modern philosophers. We under
stand by the quantity of motion the product of the mass by the velocity,
so that the mass of the body being as 2 and the velocity as 3, the
quantity of motion of the body will be as 6. Thus if there were two
concurrent bodies, multiplying the mass of each by its velocity and
taking the sum of the products, it is maintained that this sum must
be the same before and after the concourse.
We begin now to be disabused of this opinion, especially since it
has been abandoned by some of its most ancient, most skilful, and
most eminent defenders, and above all by the author himself of the
" Search after Truth." 2 But in this case an inconvenience has arisen,
namely, that we have been thrown too far into the other extreme, and
do not recognize the conservation of anything absolute which might
hold the place of the quantity of motion. But our mind looks for
this, and it is for this reason that I remark that philosophers who do
1 (ierhardt, Leibniz, math. Schrift., II. 2 [Vol. 6], pp. 215-231. Published
from the Ms. in the Royal Library at Hanover. Written, according to Ger-
hardt, probably about 1691, cf. op. cit., Einleitung, p. 14.— TR.
2 Cf. ante, p. 176, note 1. — TR.
2 u
658 LEIBNITZ'S CRITIQUE) OF LOCKE
not enter into the profound discussions of mathematicians have diffi
culty in abandoning an axiom such as this of the quantity of con
served motion without giving themselves another to which they may
hold.
It is true that the mathematicians who a long time since established
the rules of motion based on experiments have remarked that the
same relative velocity is preserved between the concurrent bodies.
For example, if one of the two is at rest, or if both are in motion, and
proceed the one against the other, or in the same direction, there is a
relative velocity, with which they approach or depart the one from the
other ; and we find that this relative velocity remains the same, so
that the bodies depart after the impact with the velocity with which
they were approaching before the impact. But this relative velocity can
remain the same although the true velocities and absolute forces of
the bodies change in an infinite number of ways, so that this conser
vation does not concern that which is absolute in bodies.
I remark also another conservation, namely, that of the quantity of
progress, but neither is this the conservation of that which is abso
lute. I call progress the quantity of motion with wrhich a body pro
ceeds in a certain direction, so that if the body went in a contrary
direction, this progress would be a negative quantity. Now if two or
more bodies are concurrent, we take the progress from the direction
whence proceeds their common centre of gravity, and if all these
bodies proceed from the same direction, then we must take the sum
of the progress of each for the total progress ; and it is plain that in
this case the total progress and the total quantity of motion of the
bodies are the same thing. But if one of the bodies proceeded from a
contrary direction, its progress in the direction in question would be
negative and consequently must be subtracted from the others in
order to have the total progress. Thus if there are only two bodies,
one of which proceeds in the direction of the common centre, and the
other in a contrary direction, from the quantity of motion of the first
must be subtracted that of the second, and the remainder will be the
total progress. Now it will be found that the total progress is con
served, or that there is as much progress in the same direction before
or after the impact. But it is also plain that this conservation does
not correspond to that which is demanded of something absolute.
For it may happen that the velocity, quantity of motion, and force of
bodies being very considerable, their progress is null. This occurs
when the two opposed bodies have their quantities of motion equal.
In such case, according to the sense we have just given, there is no
total progress at all.
Long since I corrected and rectified this doctrine of the conser
vation of the Quantity of Motion, and put in its place the con
servation of some other absolute thing; but as regards the precise
APPENDIX 659
form in which this doctrine should be conceived,1 that is to say, the
conservation of absolute force, it is true that commonly they do not
appear to have entered sufficiently into my reasons nor to have appre
hended the beauty of that which I have observed, as I remark in all
that has been published in France or elsewhere on the laws of motion
and mechanics, even after what I have written on Dynamics. But as
some of the most profound mathematicians after many discussions
have yielded to my opinion, I promise myself with time general ap
proval. To return then to what I said of the conservation of absolute
force, we must know that the origin of the error concerning the quan
tity of motion arises from that which has taken it as force. We have
been led, I think, naturally to believe that the same quantity of the
total force abides before or after the impact of the bodies, and I have
found this very true. Xow the quantity of motion and force being
taken as one and the same thing, we have concluded that the quan
tity of motion is conserved. What has contributed the most to con
found force with quantity of motion is the abuse of the static doc
trine. For we find in statics that two bodies are in equilibrium when
in virtue of their position their velocities are reciprocal to their
masses or weights, or when they have the same quantity of motion.
But we must know that this equality of force in this case arises
from another principle, for generally absolute force must be estimated
by the violent effect which it can produce. I call the effect violent
which consumes the force of the agent, as, for example, to give such
a velocity to a given body, to raise a given body to such a height, etc.
And we can conveniently estimate the force of a heavy body by the
product of the mass or of the weight multiplied by the height to
which the body might rise by virtue of its motion. Now two bodies
being in equilibrium, their heights to which they might rise or from
which they might descend are reciprocal to their weights, or rather
the products of the heights by the weights are equal. And it happens
only in the case of equilibrium or of dead force, that the heights are
as the velocities, and that thus the products of the weights by the
velocities are as the products of the weights by the heights.2 This,
I say, happens only in the case of dead force, or of the infinitely small
motion which I am accustomed to call solicitation, which takes place
1 The French is : " Mais justement de cette chose qu'il fallait." — TR.
2 On the margin of the manuscript Leibnitz has remarked: "Thus it is
astonishing that Descartes has avoided so well the rock of velocity taken for
force, in his little treatise on Statics or dead force, where there was some
danger, having reduced all to weights and heights, when it was indifferent,
and that he has abandoned the heights for the velocities in the case where
he should have done wholly the contrary ; that is to say, when he discusses
percussions or living forces which must be measured by weights and heights."
— Gerhardt's Note. — TR.
LEIBNITZ'S CRITIQUE OF LOCKE
when a heavy body tries to commence movement, and has not yet
conceived any impetuosity ; and this happens precisely when bodies
are in equilibrium, and, trying to descend, are mutually hindered.
But when a heavy body has made some progress in descending freely,
arid has conceived some impetuosity or living force, then the heights
to which this body might attain are not proportional to the veloci
ties, but to the squares of the velocities. And it is for this reason
that in case of living force the forces are not as the quantities of
motion or as the products of the masses by the velocities.
Nevertheless it is noticeable, and has contributed to the error,1 that
two bodies unequal in absolute living force, — for it is of this I speak,
— but whose quantity of motion is equal, can stop each other, which
fact has made men believe them absolutely equal in force ; as, for
example two bodies A of mass 3 velocity 2, and B of mass 2 velocity o.
For although A is absolutely weaker than B, A being able to raise
a pound only 12 feet, if B can raise a pound 18 feet ; nevertheless in
the concourse they can stop each other, the reason of which is that
bodies are hindered only according to the laws of dead or static force.
For being elastic as we suppose, they act between themselves only by
dead forces or according to the equilibrium in the concourse, that is
to say, by inassignable changes, because in pressing, resisting, and
continually weakening each other more and more until they coine to
rest, they destroy one another at each moment only by the infinitely
small motion, or dead force, equal on both sides; now the quantity of
dead force is estimated according to the laws of equilibrium by the
quantity of motion, infinitely small in truth, but whose continual
repetition exhausts at last the whole quantity of motion of the two
bodies, which being supposed equal in both bodies, each quantity of
motion is exhausted in the same time, and consequently the two
bodies are reduced to rest in the same time by the pressures of their
elasticities, which, restoring themselves afterwards, reproduce the
motion. It is (in) this continual diminution of the quantity of motion
according to the equilibrium in the concourse of the two elasticities
that the cause of this paradox consists, that two absolute unequal
forces, but which have the quantities of motion equal, must stop each
other because this happens in a relative action where the contest
takes place only according to the quantities of motion infinitely small
continually repeated.
Now it is found by reason and by experiment, that it is licing abso
lute force, or that which is estimated by the violent effect it can pro
duce, which is preserved, and nowise the quantity of motion. For if
this living force could ever be augmented, the effect would be more
1 The French text reads: " Cependant il est remarquable et a coritribuer a
1'erreur," etc. The reading should he: " et a contribue," etc. — TK.
APPENDIX 661
powerful than the cause, or rather the perpetual mechanical motion,
that is to say, which could reproduce its cause and something more,
which is absurd. But if the force could be diminished, it would perish
at last entirely; for never being able to increase, and being able never
theless to diminish, it would always go more and more into decay, which
is without doubt contrary to the order of things. Experiment con
firms it also, and we shall find always that if bodies should convert
their horizontal into ascending motions, they could always raise on
the whole the same wreight to the same height before or after the
impact, supposing that no force has been absorbed in the impact by
the parts of the bodies, when these bodies are not perfectly elastic,
without speaking of that which the medium, the base, and other cir
cumstances absorb. But as this is a thing which I have sufficiently
explained before, I will not repeat it here.
Now I am very happy to give still another turn to the matter and
to show further the conservation of something approaching more the
quantity of motion, namely, the conservation of moving action (V action
mot rice}. Here then is the general rule that I establish. Whatever
changes may take place between concurrent bodies, of whatever num
ber, there must always be in the concurring bodies between themselves alone
the same quantity of moving action in one and the same interval of time.
For example, there must be during this hour as much moving action
in the universe or in the given bodies, acting between themselves
alone, as there will be during any other hour whatever.
To understand this rule, it is necessary to explain the estimate of
moving action (faction motrice), wholly different from the quantity
of motion, in the manner that the quantity of motion has been
wont to be understood as has been explained above. Now in
order that the moving action may be estimated, we must first esti
mate the formal effect of motion. This formal or essential effect of
motion consists in that which is changed by the motion, namely, in
the quantity of the mass which is transferred, and in the space or in
the length through which this mass is transferred. There is the
essential effect of motion, or that which finds itself changed : for this
body was there, now it is here : the body is so much and the distance
is so much. 1 conceive in order to greater facility that the body is
moved so that each point describes a straight line equal and parallel
to that of every other point of the same body. I mean also a motion
uniform and continuous. This assumed, the formal effect of motion
is the product of the mass which is transferred multiplied by the
length of the removal, or rather the formal effects are in reason com
posed of the masses and the lengths of the removal, so that a body, as
2, being transported the length of 3 feet, and another body, as 3, being
transported the length of 2 feet, the formal effects are equal. It is
necessary carefully to distinguish what T here call the formal effect, or
662 LEIBNITZ'S CRITIQUE OF LOCKE
that essential to motion, from that which I called above the violent
effect. For the violent effect consumes the force and is exercised
upon something without; but the formal effect consists in the body in
motion, taken in itself, and does not consume the force, and even
conserves it rather, since the same translation of the same mass must
always be continued, if nothing from without prevents ; it is for this
reason that the absolute forces are as the violent effects which con
sume them, but nowise as the formal effects.
Xow it will be easier to understand what moving action (I' act ion.
motrice) is : it must then be estimated not only by the formal effect
which it produces, but also by the vigor or velocity with which it pro
duces it. We wish to transport 100 pounds to a distant place ; that
is the formal effect which is demanded. One desires to do it in one
hour, another in two hours ; I say that the action of the first is double
that of the second, being doubly quick with reference to an equal
effect. I suppose always continual and uniform motion. We may
say also that a body, as 3, being transported the length of 5 feet, in 15
minutes, is the same action as if a body, as 1, were transported the
length of one foot in one minute.
This definition of moving action (Vaction motrice) is justified suffi
ciently a priori because it is manifest that in a purely formal action
taken by itself, as is here that of a moving body considered by itself,
there are two points to examine, — the formal effect or that which is
changed, and the promptness of the change ; for it is very manifest
that that which produces the same formal effect in less time is the
more active. But if any one is obstinately bent upon disputing with
me this definition of moving action, it would suffice me to say that I
am free to call moving action what I just explained, provided that
nature justifies afterwards the reality of this nominal definition, which
will be when I shall show that it is precisely this whose quantity
nature conserves.
Now since moving action is that which comes by multiplying the
formal effect by the velocity, I wish to give more distinctly the esti
mate of velocity. We know that when two movable bodies run over
uniformly the same space in unequal times, the velocity of that one
which runs over it in less time will be the greater, in proportion as the
time is shorter. Thus the spaces gone over being equal, the velocities
are reciprocally proportional to the times. But if the times were
equal, the velocities would be as the spaces gone over. For one body
in motion having gone over a foot in one minute, and the other two
feet, it is manifest that the velocity of the second is double. Thus
the velocities are in reason composed of the direct of the spaces gone
over and of the reciprocal of the times employed. Or what is the
same tiling, to estimate the velocity, we must take the space and
divide it by the time. For example, A accomplishes 4 feet in 3
APPENDIX
663
seconds and B 2 feet in 1 second; the velocity of A will be as 4
divided by 3, namely as f, and the velocity of B will be as 2 divided
by 1, namely as 2, so that the velocity of A will be to that of B as f to
2, that is to say, as 2 to 3.
Now the question is to verify the conservation of the moving action
(V action motrice}. I can give its general demonstration in a few
words, because I have already proved elsewhere that the same force is
conserved, and because at bottom the exercise of force or the force
taken at the time is action, the abstract nature of force consisting
only in that. Thus since the same force is conserved, and since action
is the product of the force by the time, the same action will be con
served in equal times. But I wish to verify it by the detail of the laws
of motion established by experiment and commonly received. I shall
content myself with one example ; but we shall find it the same in
every other example we might choose. And indeed we could see at
once the general reason of it, by making the calculation in abstracto, or
in general and by letters, without employing any particular numbers.
But to suit the intelligence of everybody I prefer to give an example
in numbers.
Let there be a right angle LMN (Fig. 3), whose sides LM, MN may
11 Dc
6 4
i <B<
IB"
~ Dc
2 -
,D,
?M N
/UiC <C3C 3E „£ ,E 4E
/ 3AX «_! 6. 2. 5i
/ .A 9 3 39
FIG. 3.
be prolonged at discretion. Let a straight line AM be taken, so that
prolonged beyond the point M it would cut the angle LMN into two
equal parts. We might consider ^AM as the hypotenuse of a square
whose side may be called 1. This being so, I suppose that the body, A,1
1 We take no account here of the thickness of the bodies, which we suppose
inconsiderable. — Leibnitz's Note.
664 LEIBNITZ'S CRITIQUE OF LOCKE
being in the place ^A at the moment 1, A goes from the point r4 to the
point M, during the time 1, 2, and there meets at the moment 2 the
two bodies B and C, which had been in repose during the 1, 2, which
is known in the figure in that their place is designated by XB and by
,/j, as also by ^C and by 2C. Now the body A meeting the two bodies
in M at the moment 2, being in Mor2.4, will drive them forward and
come to rest in M, a point which will also be ;iA and 4A, because A- will
remain there during the times 2, 3 and 3, 4, as I suppose the two
mutually equal, and to the times 1, 2. But B will go towards L from
the moment 2 during the time 2, 3 with a velocity as 1, and will meet
at the moment 3 the body D, which had before gone in front of it
during the times 1, 2, from the place VD to the place 9Z), and during
the times 2, 3, from the place 2D to the place 3Z>, with a velocity as ),.
Now B, meeting D at the moment 3, will give it the velocity »D4D ;
that is to say, in the times 3, 4, XZ) will reach 4Z>, and during that
time. B will go from J3 to 4B with the velocity :iB±B. It will be the
same on the other side, where C, pushed by A in the moment 2, will
go towards N with the velocity 1, and will meet, at the moment 3, the
body E, which goes against it, having gone before, during the times 1, 2,
from the place ^E to the place 2E, and during the times 2, 3 from the
place 2E to the place »E, with a velocity as |. Now C, meeting E at
the moment 3, will give it the velocity 3E4E; that is to say, that in
the times 3, 4, it comes from 3E to 4E. And during this time, C will
go from 3C to 4C with the velocity ?>C4C.
The register of the masses and velocities, follows.
The masses of the bodies A, B, C, Z>, E are 1, 1, 1, 2, £.
During the times 1, 2 the velocities of the bodies .1, B, (7, D, E are
V2, 0, 0, J, f .
During the times 2, 3 the velocities of the bodies A, B, C, D, E
are 0, 1, 1, J, f .
During the times 3, 4 the velocities of the bodies A, B, C\ D, II
;»re 0, !, i, f, -1/-, where it is to be remarked that the body C, instead
of advancing, reflects backward with the velocity ^.
The justification of these numbers will be found in the rules
or equations which we shall assign farther on.
Let us now make the calculation of the moving actions (actions
mo/rices') during the times equal between them — 1, 2: 2, 3 ; 3, 4.
During the times 1, 2.
A is in mass 1, the length of the transfer ^^A is ^2. Then
multiplying one by the other, the formal effect is ^2. The
velocity comes from dividing the length ^/2 by the time 1, which
makes ^/'2. And multiplying the effect by the velocity, the moving
action is 2.
B and C are at rest during this time in j/J, o/J, or jC. 2C, conse
quently their moving action is 0.
APPENDIX 065
D is in mass 2, the length of the transfer -J, the formal effect
2 by £ or 1. The length £ being divided by the time 1, the velocity -£
arises, and the effect multiplied by the velocity is 1 by £, or J, which
is the action of D.
E is in mass J, the length of the transfer f, consequently the
effect |. Now the length f divided by 1 gives the velocity f, which,
multiplied by the effect, furnishes f the action of E.
And the sum of all the moving actions of the bodies /I, B, C, Z).
E, during the times 1, 2, is 2 + 0 + 0 + J + ij- = £f.
During the times 2, 3.
.4 is at rest, and its action is 0.
B is in mass 1, the length of the transfer 1 (namely, »BSB), the
formal effect 1 ; the length 1 divided by the time 1 gives the velocity
1, which, being multiplied by the effect 1, 1 arises, which is the action
of B.
C ; the calculation is the same in regard to C and there arises the
same action 1 .
D has the same action as in the preceding time ; namely, \.
E. likewise has the same action as in the preceding time; namely, |.
And the sum of all the moving actions of the bodies A, B, C, D, E,
during the times 2, 3, is 0 + 1 + 1 -f \ + f = }|, as before.
Finally, during the time 3, 4.
-1 is at rest, and its action is 0.
B is in mass 1, the length of the transfer, namely, 3/?4#, is £, conse
quently the effect is |. The same length, •£, divided by the time 1,
gives I for the velocity, which multiplied by the effect, -J- arises, the
action of />'.
f1 is in mass 1, the length of the transfer ..C4C is |, consequently
the formal effect is ^. For it matters not here when we seek absolute
things, whether C advances by ;;C4C, or reflects backward, as it does
in fact. The same length, ', divided by the time 1 gives the velocity }„
which, multiplied by the effect, there arises -/T as the action of C.
D is in mass 2, the length of the transfer :,D4D is f , consequently
the effect is |. The same length divided by the time 1 is |, or the
velocity, which multiplied by the effect, there arises ff, which is the
action of D.
E is in mass £, the length of the transfer is V>, the effect -£. The
same length divided by the time 1 is y, that is to say, the velocity,
which, multiplied by the effect, produces f *- for the action of E.
And the sum of all the moving actions of the bodies A, B. C, D, E,
during the time 3, 4, is
0 + ! + J_ + ±5.i^ = 18 + 2 + 225 + 196 _ 441 _ 49
9 81 18 81" 162 ~162~18'
as in each one of the preceding times.
666 LEIBNITZ'S CRITIQUE OF LOCKE
I have followed in this calculation the general method, for as the
moving actions are not only equal in equal times, but proportional to
the times in unequal times, I have divided the space by the time, in
order to have the velocity ; but when the time is always the same, as
here, and thus we can take it as unity, the division by the time changes
nothing, and consequently for the velocity we can take the number of
the length of the transfer, the velocities being as the spaces : whence
it is manifest that the effect being the product of the mass and the
space, and the velocity being as the space, the action is as the product
of the mass by the square of the space of the transfer (we mean a
horizontal transfer in falling bodies), or as the product of the mass by
the square of the velocity. Now, I shall prove, further on, in the 3d
equation, that the sum of these products of the masses by the squares
of the velocities is conserved in the concourse of the bodies. Con
sequently, it is proved that the moving action is conserved, without
speaking of other proofs by which I have shown elsewhere that the
forces are conserved, and that the forces are as the products of the
masses by the squares of the velocities, while the actions are as
the products of the forces by the times, so that if we did not know
elsewhere this estimate and conservation of force, we might learn it
here, in finding by the calculation in detail, or even in general, by the
3d equation, further on, that the moving action is conserved ; now it
is clear that the moving actions are in reason composed of the forces
and the times, and the times being the same, the moving actions are
as the powers or forces.
But shall we be astonished whence comes this success, which will
never fail, however intricate may be the example which we may
choose? It may be proved a priori, independently of the rules of
motion received ; and this is what I have shown many times in dif
ferent ways. But here I shall show that it is proved by these very
rules of percussion which experience has justified, and whose rationale
we may give by the method of a boat, as Huygens has done, and in
many other ways, although we are always obliged to assume something
non-mathematical, which has its source higher. But I shall reduce
the whole to three equations very simple and beautiful, and which
contain all which concerns the central concourse of two bodies in one
and the same straight line.
Conspiring velocities
of the body a before the impact v after x.
b y
I call these conspiring velocities, because I suppose they all tend from
the side whence proceeds the centre of gravity common to the two
bodies. But if perchance any velocity proceeds really in the contrary
direction, then the letter which expresses the conspiring velocity sig
nifies a negative quantity. But we shall always take the body a as a
APPENDIX: 667
body whose velocity is really conspiring, or proceeds from the side of
the centre of gravity before the impact, and also in such a manner
that the body a follows and does not precede the common centre of
gravity. Thus the signs do not vary in v, but they may vary in y, z, x.
Here, now, are our three equations : —
I. Lineal equation, which expresses the conservation of the cause
of the impact, or of the relative velocity
v — y = z — x,
and i- — y signifies the relative velocity between the bodies before the
impact with which they approach, and z — x signifies the relative
velocity with which they depart after the impact. And this relative
velocity is always the same in quantity before or after the impact,
supposing that the bodies are very elastic, which this equation states.
It is necessary only to remark that while the signs vary in the explica
tion of the detail, this general rule will embrace all the particular
cases. This also occurs in the following equation : —
II. Plane equation, which expresses the conservation of the common
or total progress of the two bodies
av + by — ax + bz.
I call progress here the quantity of motion which proceeds from the
side of the centre of gravity, so that if the body b, for example, should
proceed in the contrary direction before the impact, and thus its con
spiring velocity y be negative or be expressed by — (?/), understand
ing by (y) mass (molern), or that which is positive in //, then the
progress of a will be av, the progress of b will be — b(y}. And the
total progress will be av — b(y), which is the difference of the quanti
ties of motion of the two bodies. If the bodies a and b proceed from
one and the same side before and after the impact, these letters, v, y,
x, z, signify only conspiring velocities real or affirmative, and conse
quently in this case it appears by this equation that the same quantity
of motion will be conserved after and before the impact. But if the
bodies a and b should proceed in a contrary direction before the
impact and in the same direction after the impact, the difference of
the quantity of motion before the impact would be equal to the sum
of the quantity of motion after the impact. And there will be other
similar variations according to the variation of the signs of the letters
y, x, z.
III. Solid equation, which expresses the conservation of the total
absolute force or of the moving action
aw + byy — axx + bzz.
This equation has this excellence, that all the variations of the signs
which can arise only from the diverse direction of the velocities y, x,
z, y cease, by the fact that all the letters which express these veloci-
068 LEIBNITZ'S CRITIQUE OF LOCKE
ties mount here to the square. Now — y and -f y have the same
square + yy, so that all these different directions of y produce noth
ing more. And it is also for that reason that this equation gives
something absolute, independent of the relative velocities, or of the
progressions from a certain side. The question here concerns only the
estimating of masses and velocities, without troubling ourselves from
what side these velocities arise. And this it is which satisfies at the
same time the rigor of the mathematicians and the wish of the philoso
phers, — the experiments and reasons drawn from different principles.
Although I put together these three equations for the sake of beauty
and harmony, nevertheless two of them might suffice for our needs.
For, taking any two of these equations, we can infer from them
the remaining one. Thus, the first and the second give the third
in the following manner. By the first, we shall have v -f x= y 4- ~;
by the second, we shall have o, r — x = /;, z — y ; and, multiplying one
equation by the other, according to the corresponding sides, we shall
have «, v — x, v -f x = b, z — y, z -f ?/, which makes aw — axx = bzz — byy,
or the third equation. Tn the same way, the first and the third give
the second ; for a, vv — xx = ft, zz — yy, which is the third, divided by
the first v 4- x = z + y, side by side, we shall have «, vv — xx, :, v -f x — b,
zz — yy, :, z -f y, which makes a, v — x = b, z — y, that is, the second
equation. Finally, the second and the third equation give the first.
For the third o, vv — x-x = b, zz — yy divided by the second, namely,
by r/, v — x = ft, z — y, gives
which makes v + x = z + y, according to the first equation.
I would add only one remark, which is that many distinguish
between hard and soft bodies, and the hard themselves as elastic
or not, and build thereupon different rules. But we may take bodies
naturally as hard-elastic, without however denying that the elas
ticity must always come from a fluid more subtile and penetrating,
whose motion is disturbed by the tension or by the change of the
elasticity. And as this fluid must be composed itself in its turn of
little solid bodies, elastic between themselves, we see well that this
replication of solids and of fluids continues to infinity. Xow this
elasticity of bodies is necessary to nature, in order to obtain the
execution of the grand and beautiful laws which its infinitely wise
author has proposed, among which not the least are these two laws
of nature which I first made known, the first of which is the law
of the conservation of absolute force or of moving action in the uni
verse, with some other absolutely new conservations which depend
upon it and which I will explain some day,' and the second is the
law of continuity, in virtue of which, among other effects, every change
APPENDIX 669
must take place through inassignable passages and never by a leap.
This also is the reason why nature suffers no hard non-elastic
bodies. In order to show this, let us pretend that a hard non-elastic
globe proceeds to strike against a similar globe at rest : after the
impact it is necessary that the two globes rest, in which case the
law of the conservation of force is violated, or that there be some
motion and that the globe which was at rest receive it, being unable
to be taken as immovable, although even if it should feign to be
such, the striking body (in order to preserve the force) would nec
essarily be reflected suddenly backward. This is a forbidden (defendu)
change, since it would be by a leap, a body which proceeds from a
certain side being obliged to abate its motion, even to rest, before
beginning to proceed gradually further and further backward. But
the globe which is struck being obliged to receive motion, there
will also be a change by a leap, the struck globe which was at rest
being obliged to receive a certain degree of velocity suddenly, not
being pliable so as to receive it gradually and by degrees. It being
also manifest, as is necessary, either that the globe striking passes
suddenly to rest, which would be already a change by a leap, or that
if this striking globe retains a certain velocity, the struck globe which
was at rest receives suddenly an amount which is not less than that
of the striking globe, since the globe struck must either stop the
striking globe, or go before it. Thus the striking globe passes
suddenly from velocity to rest, or at least the struck globe passes
suddenly from rest to a certain degree of velocity, without passing
through the intermediate degrees, which is contrary to the law of
continuity, which admits no change by a leap in nature. I have also
many other reasons all of which concur in banishing hard non-elastic
bodies, but this is not the place to enlarge upon them.
But it is necessary to admit, that although bodies must be thus
naturally elastic in the sense which I have just explained, nevertheless
the elasticity often appears insufficient in the masses or bodies which
we employ, even if these masses should be composed of elastic parts
and should resemble a sack full of hard balls which would yield to a
moderate impact, without leaving the sack, as we see in the case of soft
bodies or those which yield without recovering themselves sufficiently.
The reason is that the parts are not sufficiently united therein to trans
fer their change to the whole. Whence it comes that in the impact of
such bodies a part of the force is absorbed by the small parts which
compose the mass, without this force being given to the whole ; and
this must always happen when the pressed mass does not recover per
fectly ; although it also happens that a mass shows itself more or less
elastic according to the different manner of the impact, witness the
water itself which yields to a moderate impression, and makes a can
non-ball rebound.
670 LEIBNITZ'S CRITIQUE OF LOCKE
Now when the parts of the bodies absorb the force of the impact, as
a whole, as when two pieces of rich earth or of clay come into collision,
or in part, as when two wooden balls meet, which are much less elastic
than two globes of jasper or tempered steel ; when, I say, some force is
absorbed by the parts, it is as good as lost for the absolute force, and
for the respective velocity, that is to say, for the third and the first
equation, which do not succeed, since that which remains after the
impact has become less than what it was before the impact, by reason
of a part of the force being turned elsewhere. But the quantity of prog
ress, or rather the second equation, is not concerned therein. Arid
even the motion of this total progress remains alone, when the two
bodies proceed together after the impact with the velocity of their com
mon centre, as do two balls of rich earth or clay. But in the semi-
elastics, as two wooden balls, it happens still further that the bodies
mutually depart after the impact, although with a weakening of the
first equation, following this force of the impact which has not been
absorbed. And in consequence of certain experiments touching the
degree of the elasticity of this wood, we might predict what should
happen to the balls which should be made of it in every kind of col
lision or impact. But this loss of the total force, or this failure of the
third equation, does not detract from the inviolable truth of the law
of the conservation of the same force in the world. For that which
is absorbed by the minute parts is not absolutely lost for the universe,
although it is lost for the total force of the concurrent bodies.
ESSAY ON DYNAMICS IX DEFENCE OF THE WONDER
FUL LAWS OF NATURE IN RESPECT TO THE FORCES
OF BODIES, DISCLOSING THEIR MUTUAL ACTIONS
AND REFERRING THEM TO THEIR CAUSES1
[From the Latin]
PART I
From the time we made mention of the founding of a New Science
of Dynamics, many distinguished men in various places have asked
for a fuller explication of this doctrine. Since, therefore, we have not
1 Gerhardt, Leibniz, math. Schrift., II., 2 [Vol. 6], pp. 234-246. Dutens,
Leibnit. op. om., 3, 315-324. First published in the " Aeta Eruditor. Lips.," in
April, 1695. — TR.
APPENDIX 671
yet leisure to compose the book,1 we will give in this place those things
which may kindle some light, which perhaps will return to us with
interest, if, indeed, we shall elicit the opinions of those who unite
energy of thought with elegance of speech, whose judgments also we
openly confess will be acceptable to us, and we hope useful in the set
ting forward of the work. We have elsewhere suggested that there
is in corporeal things something besides extension, nay, prior to ex
tension, namely, the force itself of nature everywhere implanted by its
Author, which consists, not in the simple faculty with which the schools
seem to have been content, but, besides, is provided with a tendency
(conatu) or effort (nisu) which will have its full effect unless impeded
by a contrary tendency (conatu). This effort often appears to the
senses, and in my judgment is known everywhere in matter by the
reason, even when it does not appear to the sense. But if now this
force must not be assigned to God through a miracle, it is certainly
necessary that this force in bodies themselves be produced from the
body itself, nay, that it constitute the inmost nature of bodies, since
to act is a mark of substances, and extension means nothing else than
the continuation or diffusion of the already presupposed struggling
and withstanding, that is, resisting substance, so far is it from
being itself able to produce substance. Nor is it necessary, because
every corporeal action arises (est) from motion, and motion itself does
not exist unless from motion, either in the body already before exist
ing or impressed from something external to it (aliunde). For
motion (just as time) never exists, if you reduce the thing to aKpt-
/JaaiA, because a whole never exists, when it has not coexisting parts.
And nothing is so real in itself, as that momentary increment (momen-
taneuni) which must be constituted in a force striving for change. To
this, therefore, returns whatever there is in corporeal nature besides
the object of geometry or extension. And by this method, in fact,
regard is had at the same time for both the truth and the doctrine of
the ancients. And as our age has freed from contempt the atoms of
Democritus, the ideas of Plato, and the tranquillity of the Stoics in the
best nexus of things, so now the traditions of the Peripatetics concern
ing forms or entelechies (which deservedly seemed enigmatical and
scarcely rightly perceived by the authors themselves) will be referred
to intelligible notions, so that we think it necessary rather to explain
the philosophy thus received by so many ages, so that it may be con
sistent (where this is permitted) and to illustrate and then increase
it with new truths, than to destroy it.
And this kind of studies seems to me especially suited both to the
intelligence (prudentice) of the teacher and to the profit of the learners,
1 For the work referred to, cf. Gerhardt, Leibniz, math. Schrift., II., 2
[Vol.6], pp. 2Slsq.— T#.
672 LEIBNITZ'S CRITIQUE OF LOCKE
so that we may not seem more desirous of destroying than of building,
nor, be tossed between perpetual changes of doctrine, daily uncertain
because of the pride of audacious geniuses, but at length the human
race, the lust of sects being curbed (which the inane glory of change
•[novandi'] stimulates), the certain dogmas established, without stum
bling, not less in philosophy than in mathematics, will make further
advance, since in the writings of distinguished men, ancient and mod
ern (if you take away entirely those things in which they speak too
severely against others), there is wont to be very much that is true and
good, which deserves to be rescued and to be distributed into the pub
lic treasury. And would that men preferred to do this rather than
spend their time in censures by which they only appease their own
vanity. But somehow very many even hostile views do not displease
us certainly, whom fortune has so favored in certain new viewrs of ours,
that friends often bade us think of these only, and each view is
considered according to its own value, although diverse ; the reason
of which perhaps is that in discussing many things we have learned
to despise nothing. But now let us return to our subject.
Active force (which with some you call not ill power — virtus) is two
fold, namely primitive, which exists in every corporeal substance per se
(since I think a wholly quiescent body abhorrent to the nature of
things), or derivative, which by a limitation as it were of the primi
tive, resulting through the conflicts of bodies with each other, is vari
ously exercised. And the primitive force indeed (which is nothing-
else than evrcXe^eta rj irpwrrj) corresponds to the substantial soul or
form, but indeed for this reason pertains only to general causes, which
cannot suffice for the explanation of phenomena. And so we agree
with those who deny that forms must be employed in handing down
the particular and special causes of sensible things : to point out
which is worth while, lest, while we lead them as it were back again
to the open fountains of things, at the same time we seem to desire
to return to the 'vain repetitions' (battologias) of the vulgar school.
Meanwhile a knowledge of them is necessary to correct philosophiz
ing, nor may any one think he is master of the nature of body, unless
he has turned his mind to such things and understood that that crass
notion of corporeal substance is imperfect, not to say false, and
depends upon the imagination alone and was introduced inconsider
ately some years since by an abuse of the corpuscular philosophy (in
itself excellent and most true), as indeed is evident by this argument
which does not entirely exclude cessation and rest from matter, and
cannot bring forward reasons for the laws controlling the derivative
force of nature. In like manner passive force also is twofold, either
primitive or derivative. And indeed the primitive force of enduring or
resisting constitutes that very thing which is called primary matter, if
you rightly interpret it, in the schools, by which it happens that body
APPENDIX 673
is not penetrated by body, but forms an obstacle to it, and it is en
dowed at the same time with a certain laziness, so to speak, that is,
repugnance to motion, and does not indeed suffer itself to be set in
motion unless by the somewhat broken force of the active body.
Whence afterwards the derivative force of enduring variously exhibits
itself in secondary matter. But it is our part now to proceed farther,
having removed those general and primitive forces and substituted
those by which we are taught that because of form every body always
acts and because of matter every body always endures and resists,
and in this doctrine of derivative forces and resistances to investigate
how far bodies prevail by various efforts or again variously resist ; for
the laws of actions, which are known not only by reason, but are
confirmed also by sense itself through phenomena, are adapted to
these.
Derivative force therefore, by which bodies in action act mutu
ally on each other or mutually suffer from each other, we under
stand in this place as no other than that which is connected with
motion (i.e. local), and in turn tends to produce further local
motion. For we admit that through local motion other material
phenomena can be explained. Motion is a continual change of
place, and thus requires time. Yet the movable element (mobile)
existing in motion, as it has motion in time, so in any moment
whatever has velocity, which is so much the greater as more space
is run over and less time is expended. Velocity taken in connection
with direction is called conatus ; but impetus is the product of the mas.^
of the body into the velocity, and its quantity is so much that the
Cartesians are wont to call it the quantity of motion, namely, the mo
mentary increment (momentaneam) , although, speaking more accurately,
the quantity of motion itself, existing forsooth in time, arises from the
aggregate of the impetuses (equal or unequal) existing in the mov
able element in the given time multiplied in order into the time. We,
nevertheless, in discussing with these have followed their fashion of
speaking. Nay even as (not inconveniently for the doctrinal use of
speaking) we can distinguish the accession which now is made from
the accession already made or to be made, as an increment of accession
or element ; or as we may distinguish the present descent from the
descent already made, which it increases ; so we can discern and call
Motion the momentary or instantaneous element of motion diffused by
the motion itself through a period of time ; and so that which is com
monly ascribed to motion is called the quantity of motion. And although
in the use of terms we are compliant (faciles) in accord with an ac
cepted interpretation, nevertheless it especially behooves us to be care
ful in their use lest we be caught by their ambiguity.
Moreover, as the estimate of motion through a period of time is.
made from infinite impulses, so in turn the impulse itself (although
t>74 LEIBNITZ'S CRITIQUE OF LOCKE
a momentary thing) is made from infinite degrees successively im
pressed upon that same movable body (mobile), and has a certain ele
ment from which, unfolded, nothing but infinity can arise.
Conceive a tube AC (Fig. 4) to revolve with a certain fixed uniform
velocity in the horizontal plane of this page about an immovable
centre C, and a ball B, existing in the cavity of
A O the tube, to be freed from its chain or impediment,
and to begin to be moved by the centrifugal force ;
it is manifest that the attempt in the beginning
to depart from the centre by which, namely, the
ball in the tube tends towards its extremity A, is
infinitely small in respect to the impulse which it
already has from the rotation, or by which with
the tube itself, the ball B tends from the place
D towards (/)), its distance from the centre being-
retained. But with the continuance for some time
FIG. 4. °f the centrifugal impression proceeding from the
rotation, from its own progress there must arise in
the ball a certain complete centrifugal impulse (D)(B), comparable
with the impulse of rotation D(D}. Hence it is evident that the
effort is twofold, elementary to be sure, or infinitely small, which T
call, also, solicitation, and formed by the continuation or repetition
of elementary efforts ; that is, the impulse (impetum) itself, although
I do not, for that reason, mean that these mathematical entities are
really so found in nature, but only that they are useful in making
accurate estimates by mental abstraction.
Hence force also is twofold: the one elementary, which I call also
dead, because motion (motus) does not yet exist in it, but only
a solicitation to motion (solicitatio ad motum), such as that of the
ball in the tube, or of the stone in the .sling, even while it is held
still by the chain ; the other, however, is ordinary force, united with
actual motion, which T call living. And an example of dead force
indeed is the centrifugal force itself, and likewise the force of gravity
or centripetal force, the force also by which the tense elastic body
(elastrum) begins to restore itself. But in percussion, which arises
from a heavy body falling already for some time, or from a bow
restoring itself for some time, or from a similar cause, the force
is living force, which has arisen from an infinite number of con
tinued impressions of dead force. And this is what Galileo meant,
when in his enigmatical manner of speaking he spoke of the
infinite force of percussion, namely if compared with the simple
effort of gravity. But although the impulse (impetus) is always
united with living force, yet we shall show below that these two are
different.
Living force in any aggregate of bodies again can be known as
APPENDIX 675
twofold, namely total, or partial ; and partial again is either re
spective or directive, that is, either proper or common to the parts.
Respective (respectiva) or proper (proprid) force is that by which the
bodies comprised in the aggregate can act among themselves mutually;
directive or common force is that by which, besides, this aggregate
can act outside itself. But I call it direct, because the total force
of direction is preserved intact in this partial force. But this alone
would remain, if suddenly the aggregate were imagined to congeal
by the intercepted motion of its parts among themselves. Whence
from respective and directive taken together total absolute force is
composed. But these things will be better understood from the
rules to be propounded below.
The ancients, as far as known, had a science of dead force
alone, and this it is which is commonly called Mechanics, treating
of the lever, block, inclined plane (where belongs the wedge and the
spiral), the equilibrium of liquids, and similar things, in which they
treat in turn only of the first tendency (conatu) of the bodies among
themselves, before they received an impulse by acting. And although
the laws of dead force can in some fashion be transferred to living
force, yet there is need of great caution, as even they may have been
deceived, for this reason, who confounded force in general with the
quantity produced by the multiplication of the mass into the
velocity, because they understood that force is dead in the regular
theory of these. For this thing happens there for a special reason,
as we already long ago suggested, since (for example), in dif
ferent descending weights, in the very beginning of motion at
least the descents themselves or the quantities of the spaces gone
through in the descent, certainly infinitely small or elementary
hitherto, are proportional to the velocities or to the efforts to descend.
But the progress being made and living force having arisen, the
acquired velocities are no longer proportional to the spaces already
run over in the descent, by which, nevertheless, we have shown
formerly and shall further show, that the force must be estimated,
but only to the elements of these velocities. Galileo began to
discuss concerning living force (although under another name, nay,
I should rather say, concept) and was the first to explain how by
the acceleration of descending weights motion arises. Descartes
rightly distinguished velocity from direction, and saw even in the
conflict of bodies that follow by which the former conditions are
least changed. But he did not rightly estimate the least change,
while he changes the direction alone or the velocity alone, since
the change moderated by mixing would be obtained from both :
but how this must come about escaped him, because to him, intent
at that time upon modal manifestations rather than upon realities,
phenomena so heterogeneous did not seem capable of being compared
676 LEIBNITZ'S CRITIQUE OF LOCKE
and modified by union, so that we shall say no more of his other
errors in this doctrine.
Honoratus Fabri,1 Marcus Marci,2 Joh. Alph. Borellus,8 Ignatius
Baptista Pardies,4 and Claudius de Chales,5 and other men very acute
in learning have published things not to be despised on motion, but
nevertheless have not shunned these capital errors. Huvgens,6 the
first that I know who has adorned our age with splendid discoveries,
seems to me in this argument also to have reached the pure and un
adulterated truth and to have freed this doctrine from paralogisms,
1 Of. ante, p. 580, note 2. — TR.
2 Johannes Marcus Marci von Kronland, 1595-1067, a German physician,
mathematician, and physicist, published his De proportione motas, sen regain
sphygmica ad celeritatem et tarditatem pulsuum, ex illius motu ponderibus
geometricis librato, absque errore metiendam, Pragae, 1639, a remarkable
work on the theory of impact, preceding by thirty years the researches of
Wallis, Wren, and Huygens. This is probably the work to which Leibnitz
here refers. — TR.
3 Giovanni Alfonso Borelli, 1608-1679, a distinguished Italian physician and
mathematician, the founder of the iatromathematical theory of medicine, was
Professor of Mathematics at Pisa and Naples. He was the author of several
medical and mathematical works, among which were Theorica mediceorum
planet arum ex causis physicis deducta, Florent., 1666; De motu animalium,
Rome, 1680-1681; De vi percussionis, Lugd. Bat., 168(5; and De Motionibus
naturalibus, a gravitate pendentibus, Lugd. Bat., 1(586. The two latter works
are probably the ones referred to by Leibnitz. For an account of his views,
cf. Lasswitz, Gesch. d. Atomistik, Hamburg u. Leipzig, 1890, Vol. 2, pp. 300-328.
— TR.
4 Ignace Gaston Pardies, 1636-1673, a French Jesuit and geometer, was
Professor of Philosophy, and afterwards of Mathematics, at Paris. In his
correspondence with Newton, he sought to explain the dispersion of light as
a diffraction by aid of the assumption that the transmission of light depends
upon a wave-movement. He intended to write a great work on Mechanics, of
which only Pts. 1 and 2, Discours du mouvement local, Paris, 1670, and La
statique ou la science des forces mouv antes, Paris, 1673, appeared. His (Eavrex
de mathematiques, etc., 4th ed., appeared a La Haye, 1710. Cf. Lasswitz,
Gesch. d. Atomistik, 2, 340. Leibnitz refers to Pardies in a communication to
H. Fabri, cf. Gerhardt, Leibniz, math. Schrift., II., 2 [Vol. 6], 81, 84 ; Gerhardt,
Leibniz, philos. Schrift., 4, 244, 247. — TR.
5 Claude Frai^ois Milliet Deschales, 1621-1678, a French Jesuit and dis
tinguished mathematician and physicist, published his Cttrsus sen mundu*
mathematicus, 3 tomi, 1st ed., Lugduni, 1674, 2d ed., 1(590. Leibnitz refers to
him briefly in a communication to H. Fabri, Gerhardt, Leibniz. philos. Schrift.,
4, 245; Leibniz, math. Schrift., II., 2 [Vol. 6], 81. Brief account of his views
is given in Lasswitz, Gesch. d. Atomistik, 2,487-490. — TR.
c Cf. ante, p. 150, note 3. The doctrine of Huygens, here referred to, is found
in his De motu corporum ex percussione (1(5(59), which was first published in
1703; Opera reliqua, AmsteL, 1728, Vol. 2; CEuvres completes, La Haye, 1888 sq.
His correspondence with Leibnitz is found in Gerhardt, Leibniz, math. Schrift.,
I., 2 [Vol. 2], 1-208. References to the doctrine of motion occur on pp. 140,
184. An account of Huygens' physical and mechanical views is given in Lass
witz, Gesch. d. Atnnnxtik, 2. :'.41-3(.)7. — Tit.
APPENDIX 677
by certain rules formerly published. Wren1 also, Wallis2 and
Mariotte,3 men excellent in these studies though diverse in method,
demonstrated nearly these same rules. But concerning the causes,
nevertheless, opinion is not the same; whence men distinguished in
these studies do not always admit the same conclusions. And indeed
the true sources of this science have not yet, as is evident, been dis
closed. ]STor indeed is what seems certain to me admitted by all :
that rebounding or reflection springs only from elastic force, that is,
from internal resistance to motion. Nor has any one before us ex
plained the notion itself of forces, which thing hitherto has disturbed
the Cartesians and others, who, even for this reason, could not com
prehend that the sum of the motion or impulse (which they regard
as the quantity of the forces) can appear different after the encounter
from before, because for this very reason they believed the quantity
of the forces to be changed.
From me, still a youth, and at that time constituting the nature of
body, with Democritus and his adherents in this matter, Gassendi
and Descartes, in inert mass alone, there escaped a little book
" Hypothesis Fhysica " 4 by title, in which I set forth a theory of
motion, at the same time abstract (abstractam) from the system and
concrete (concretnm) for the system,5 which beyond the merit of its
1 Sir Christopher Wren, 1G31-1723, best known as the architect of St. Paul's,
London, was distinguished at Oxford for his knowledge of geometry and
applied mathematics. In 1660 he was elected Savilian Professor of Astronomy
at Oxford. Newton, in his Principia. ed. 1713, p. 19, speaks highly of his
work as a geometrician. Leibnitz refers to him in the Hypoth. phys., cf.
Gerhardt, Leibniz, math. Schrift., II., 2 [Vol. 6], 26, 29, 30, 75 ; Philos. Schrift.,
4, 187, 190, 191, 236. — TR.
2 John Wallis, 1616-1703, an eminent English mathematician, appointed
Savilian Professor of Geometry, at Oxford, 1649, published his Mechanica,
sive de Motu Tractatus Geometricus, 3 parts, 1669-1671. His complete works
were published, Oxford, 1695-1699, 3 vols., fol. The correspondence between
Leibnitz and Wallis is found in Vol. 3 of this ed., and also in Gerhardt, Leibniz,
math. Schrift., I., 4 [Vol. 4], 1-82.— TR.
3 Cf. ante, p. 121, note 4. An elaborate treatise on the percussion of bodies,
De la percussion ou choc des corps, probably the one to which Leibnitz here
refers, is found in first volume of his (Euvres, Leyden, 1717. — TR.
4 Cf. Gerhardt, Leibniz, math. Schrift., II., 2 [Vol. 6], 17-80; Gerhardt, Leih-
viz. philos. Schrift., 4, 177-240; Duten's, Leibnit. op. am., 2, Pt. II., 1-48. — TR.
5 The compressed and somewhat obscure text is explained by the titles of
two essays forming the Hypothesis Physica nova. The title of the first essay
is : Theoria mot us concreti seu Hypothesis de rationibus phsKnomenorum nostri
Orbis ; that of the second is: Theoria motus abstract i seu Rationes motuuin
universalex a sensu et phsenomenis independentes. Cf. Gerhardt's Einleitung,
Leibniz, philos. Schrift., 4, 9-12, and especially the portion, there quoted, of
a letter to Foucher, found also in op. cit., 1, 415 : Krdrnann, Leibnit. op. philos.,
117; F. de Careil, Lettres et Opuscules ine'dits de Leibniz, Paris, 1854, 119-120;
Dutens, Leibnit. op. om.,2, Pt. I., 242 ; transl. Duncan, Philos. Wks. of Leibnitz,
64-65.— TR.
678 LEIBNITZ'S CRITIQUE OF LOCKE
mediocrity I see has pleased many distinguished men. I there estab
lished, having assumed such a conception of body, the fact that every
striking body gives its impulse (conatuni) to the receiving or directly
opposing body as such. For since, in the moment of attack, the
receiving body undertakes to go forward and thus run away with
itself, and that impulse (on account of the indifference then believed
by me of the body to motion or rest) must have its effect wholly in
the receiving body, unless hindered by a contrary impulse, nay, even
if hindered by it, since it is so necessary that these different impulses
should be adjusted among themselves ; it was manifest that no cause
could be given why the striking body should not attain the effect
towards which it tends, or why the receiving body should not receive
the entire impulse of the striking body, and so the motion of the
receiving body was composed of its own pristine impulse, and of the
newly received or foreign impulse. From which then I was showing
that if mathematical notions alone, — -magnitude, figure, place, — and
the change of these, or in the moment itself of impact (concursus)
the impulses to change were perceived in the body, no theory of meta
physical notions being held, namely, of power active (actricis) in form
and of inactivity (ignavice), or of resistance to motion in matter, and
so if it were necessary for the concourse of events to be determined
by the geometrical composition of impulses alone, as we have ex
plained : then it must follow that the impulse of the striking body,
even the least, is impressed upon the entire receiving body, although
the greatest, and so the greatest body at rest is dragged away by the
striking body, however small, without any retardation of this body,
since indeed no repugnance, but rather indifference of it to motion,
is contained in such a notion of matter. Whence it would not be
any more difficult to impel a large quiescent body than a small one,
and thus there would be action without reaction, and there could be no
estimate of power, since anything whatever could be proved by any
thing whatever. And since these things, and many others of the
same kind, are opposed io the order of things and conflict with the
principles of a true metaphysic, I thought at that time therefore (and
indeed truly) that the most wise Author of things in the construction
of the system shunned those things which would follow of themselves
from the mere laws of motion derived from pure geometry.
But afterwards, having examined things more deeply, T saw in
what the systematic explanation of things consisted, and regarded
that former hypothesis of the notion of the body as incomplete, and
both by other arguments and also by this itself it was proved that in
body there must be placed something besides magnitude and impene
trability, whence the consideration of forces arises, by adding the met
aphysical laws of which to the laws of extension those very rules of
motion are produced which T called systematic ; namely, that every
APPENDIX 679
change takes place gradually, and every action is accompanied with
reaction, and new force is not produced without loss of the former, and
so the one dragging always is retarded by the one dragged, and neither
more nor less power is contained in the effect than in the cause.
And since this law is not derived from the notion of mass, it must
necessarily follow from another thing, which is in bodies, namely,
from the force itself, which certainly always preserves its own quan
tity the same, although it is employed by different bodies. Hence
therefore, besides considerations purely mathematical, and subject to
the .imagination, I have concluded that certain considerations meta
physical, and perceptible by the mind alone, must be admitted, and
a certain principle superior to the material mass, and, so to speak, a
formal addition, since indeed all the truths of corporeal things can
not be concluded from logical and geometrical axioms alone, namely,
from great and small, whole and part, figure and position, but some
others must be added from cause and effect, and action and passion,
by which the reasons of the order of things are saved. Whether we
call that principle form, or evTeA.ex€la> or f°rce> does not matter, pro
vided we remember that it is intelligibly exhibited through the
notion of forces alone.
But although to-day certain distinguished men, seeing this very
thing, that the common notion indeed of matter is not sufficient,
fetch in God SLTTO ^xai/ijs, and take away all force of acting from
things, a kind of Mosaic philosophy as it were (as Fludd once called
it), I cannot assent. For although I admit that it has been very
clearly perceived by them that there is no proper influx of one cre
ated substance into another, if the thing is driven to metaphysical
strictness, and I confess even freely that all things always proceed
from a continuous creation by God; yet I think there is no natural
truth in things, the reason of which is to be sought immediately in
the divine action or will, but that always in the things themselves
something has been placed by God, whence all their predicates are
explained. It is certainly evident that God has created not only
bodies, but also souls, to which correspond the primitive entelechies.
But these things will be demonstrated elsewhere by their own proper
reasons more profoundly drawn out.
Meanwhile, although I admit an active principle superior to mate
rial notions and, so to speak, vital everywhere in bodies, yet I do not
therefore here agree with Henry More and other men, distinguished
for piety and genius, who so make use of a certain Archseus l or hylar-
chic principle even for the management of phenomena (ad phcenomena
procuranda), as if forsooth all things cannot be explained mechani
cally in nature, and as if those who undertake this seem to make way
1 Cf. Neiv Essays, ante, p. 67, note 3. — TR.
680 LEIBNITZ'S CRITIQUE OF LOCKE
with incorporeal things, not without suspicion of impiety ; or as if
with Aristotle it is necessary to imagine intelligences in the revolving
orbs, or the elements must be said to be driven up or down by their
own form, by a short (compendiosa) but useless method of teaching :
with these, I say, I do not agree, nor has that philosophy pleased me
any more than that theology of certain ones, who so believed that
Jupiter thundered or snowed that they even branded the searchers
after proper causes with the crime of atheism. In my opinion the
temperament is the best which satisfies both piety and science, so
that we admit that all corporeal phenomena indeed can be sought
from efficient mechanical causes, but we know that the mechanical
laws in the universe are derived from higher reasons, and so we make
use of a higher efficient cause only in establishing general and remote
tilings. But these once established, as often as afterwards we treat
of the near and special efficient causes of natural things, we give
no place to souls or eiitelechies, no more than to the idle faculties
or inexplicable sympathies, since the primal and most universal
efficient cause itself, must not intervene unless as far as the ends
are regarded, which the divine wisdom had in so ordering things,
that we neglect no occasion of singing his praise and the most beau
tiful hymns.
And in truth final causes (as 1 have shown by a wholly remarkable
example of an optical principle, with the strong approval of the very
celebrated Molyneux in his "Dioptrics") are repeatedly employed
with large result even in special physics, not only that we may admire
the more the most beautiful works of the supreme Author, but also
that we may sometimes in this \vay divine what through the way of
efficient causes not equally or only hypothetical ly are manifest. Thus
far perhaps philosophers have not yet sufficiently observed this use.
And it must be maintained in general, that everything in things can
be explained in two ways: through the kingdom of power or efficient
causes, and through the kingdom of wisdom or through final causes:
(rod regulating bodies as machines after the manner of an architect
according to the laics of inaqnitwle or mathematical laws, and indeed
for the use of souls ; but souls, capable of wisdom, as his own fellow-
citizens and sharers of a certain society with himself, after the manner
of a leader, nay of a father rather according to the lairs of f/oodnes.<
or moral lairs for his own glory, both kingdoms everywhere inter
penetrating, yet unconfused and undisturbed the laws of each.
so that at the same time both in the kingdom of power the great
est and in the kingdom of wisdom the best is obtained. But we
propose in this place to establish the general rules of productive
forces, which we can then use in the explanation of special efficient
causes.
"Next T came to the true, and indeed precisely the same, estimate
APPENDIX 681
of forces, by the most different ways : one indeed a priori, from the
simplest consideration of space, time, and action (which I elsewhere
will explain), the other a posteriori, namely, by estimating the force
by the effect which it produces in consuming itself. For I under
stand here not any effect, but that for which force must be expended
or in which it must be consumed, which you can call, for that reason,
violent, such as that effect is not, which a heavy body employs in run
ning through a perfectly horizontal plane, because in such an effect
however produced it always retains the same force, although also in
this very effect rightly treated, so to speak, as harmless, we have followed
this our method of estimating, but now it is laid aside by us. Further
I chose that effect of the violent effects which is especially capable of
homogeneity or division into similar and equal parts, such as exists
in the ascent of a body possessed of weight : for the elevation of a
heavy body two or three feet is precisely double or triple the eleva
tion of the same heavy body one foot ; and the elevation of a doubly
heavy body one foot is precisely double the elevation of a single
heavy body to the height of one foot ; whence the elevation of a
doubly heavy body three feet is precisely six times the elevation of
a simple heavy body one foot, supposing namely (at least for the
sake of teaching, although perhaps in truth the matter is otherwise
constituted, but the error here nevertheless is imperceptible), that
the heavy bodies gravitate equally in the greater or less distance
from the horizon. For in an elastic body homogeneity has not with
equal ease a place. When therefore I wished to compare bodies
different or endowed with different velocities, I easily saw that, if
the body A is single and the body B is double, but the velocity of
each equal, the force of that one is simple, of this double, since, in
short, whatever is placed in that once is placed in this twice. For in
B there is a body twice the equal and equivalent of A itself, and
nothing besides. But if the bodies A and C are equal, but the
velocity in A is simple and in C double, I saw that, not in short what
is in .-1, is doubled in C. since the velocity indeed is doubled, yet not
also the body. And 1 saw that here an error has been made by those
who believed that the force itself is doubled by that reduplication of
modality (niodalitatis} alone ; as already T once observed and sug
gested, and that the true and not hitherto (although after so many
Elem.ents of universal Mathematics have been written) handed-down
art of estimating consists in this, that finally it attains to something
homogeneous; that is, a reduplication accurate and of all kinds, not
only of modes, but also of things. Of which method no other better
or more remarkable specimen could be given than that which is
exhibited in this argument itself.
In order, therefore, to obtain these results, T considered whether
these very two bodies .4 and (\ equal in magnitude but different in
682 LEIBNITZ'S CRITIQUE OF LOCKE
velocity, could produce some effects equal to their causes and homo
geneous among themselves. For thus those things which by them
selves could not easily be compared, by their effects at least might be
compared accurately. I assumed,
moreover, that the effect must be
equal to its cause if it is produced
by the expenditure or consumption
v ?C of the entire force: in which case
,P it matters not in how much time it
j is produced. Let us suppose, there-
fore, the bodies A and C (Fig. 5)
\
\
\
H aC R to be heavy, and to convert their
-pIG 5 force into an ascent, which will hap
pen, if at the moment in which they
have their said velocities, A simple. B double, are known to exist at
the extremities of the vertical pendulums PA, EC. But it is evident
from the demonstrations of Galileo and others that, the body A with
a velocity as 1 at the highest ascending above the horizon HR to
the height of one foot 2A H, the body C with a velocity as 2 can surely
ascend (at the highest) to the height 2CR of four feet. Whence it
already follows that a heavy body having a velocity as 2 is in power
four times as much as the one having a degree of velocity as 1, since by
the expenditure of all its force it can accomplish, in short, four times
as much. For raising a pound (that is, itself — id est. se ipsum) four
feet, in short raises four times one pound one foot. And in the
same manner it is inferred generally that the forces of equal bodies
are as the squares of the velocities, and thence the forces of bodies
in general are in reason composed of the simple of the bodies and the
doubles of the velocities.
I have confirmed the same things to absurdity (namely, to per
petual motion) by bringing back the contrary opinion, generally
received, especially among the Cartesians, according to which forces
are believed to be in reason composed of bodies and velocities : which
method, indeed, I used repeatedly to define a posteriori two states unequal
in force, and to distinguish the greater at the same time from the less
by a certain mark. And since in substituting the one for the other,
perpetual mechanical motion or an effect more powerful than the
cause does not arise, those states are not in the least equivalent to
themselves, but that which was substituted for the other was morp
powerful because it has caused something greater to be performed.
Hut I assume as certain that nature never substitutes things unequal
to the forces themselves, but the complete effect is always equal to
the full cause ; and, in turn, those things which are equal to the
forces, with safe reckoning can be substituted by us for them with
the freest supposition, as if we made that substitution in act, and thus
APPENDIX 683
with no fear1 of perpetual mechanical motion. But if, therefore, it
were true, as men generally persuade themselves, that a heavy body
A as 2 (for so now we assume it) endowed with a velocity as 1, and
a heavy body C as 1 endowed with a velocity as 2, are equivalent to
each other, we ought to be able to substitute with impunity the one
for the other. But this is not true. For let us assume that A as 2
has acquired a velocity as 1 in the descent ^A^A from the height 2A If
less than a foot; and now in ^4 itself or in the existing horizon, let
us substitute instead of it the equivalent (as they wish) weight
(pondux) C as 1 with a velocity as 2, which ascends as far as to C, or
to the height of four feet. And so by the descent alone of the weight
A of two pounds from the height of one foot ,2AH, and having sub
stituted its equivalent, we have accomplished the ascent of one pound
four feet, which is double the former. Therefore we have gained
just as much force, or we have produced perpetual mechanical mo
tion, which is certainly absurd. And it does not matter whether by
the laws of motions we can actually accomplish this substitution ;
for between equivalents indeed substitution can safely be made.
Although, indeed, we have thought out various plans by which it
will be accomplished actually so nearly as we wish, that the entire
force of the body A will be transferred to the body C, before at rest,
but which now (A itself being brought to rest) is alone put in motion.
Whence it will happen, that, instead of a weight of two pounds of a
velocity as 1, would succeed one pound of a velocity as 2, if these
were equivalent ; whence we have shown that an absurdity arises.
For these things are not indeed worthless, nor do they consist in
logomachies, but are of the greatest use in comparing machines and
motions. For if any one has force from water or animals or from
other cause, by which a heavy body of a hundred pounds is kept in
constant motion, so that within a fourth part of a minute of time
it can complete a horizontal circle of a diameter of thirty feet ; but
another maintains that a double weight in its place, in the same
time, uniformly accomplishes only half the circle with less expendi
ture, and reckons that to you as if it were a gain ; be it known that
you are deceived and caught by half of the forces. But now having
put to flight errors, let us set forth a little more distinctly in the
second part of this hastily thrown-off production (Schediasmatis} the
true and truly to be admired laws of nature.2
1 Gerhardt reads, " raotu,' ' evidently a typographical error. Duteiis, Leibnit.
op. om., 3, 324, reads, " metu," which the translation follows. — TR.
2 Dutens (Leibnit. op. om., 3, 324) adds: " proponemus, mense Maio exhi-
henda," i.e. to be presented in the month of May. The article, however, never
appeared in print, hut remained in Ms. among Leibnitz's papers, and was first
printed by Gerhardt, in his edition of Leibnitz's mathematical writings. A
translation of the article is herewith given. — TR.
084 LEIBNITZ'S CRITIQUE OF LOCKE
ESSAY ON DYNAMICS IN DEFENCE OF THE WONDER-
FUL LAWS OF NATURE IN RESPECT TO THE FORCES
OF BODIES, DISCLOSING THEIR MUTUAL ACTIONS
AND REFERRING THEM TO THEIR CAUSES1
[From the Latin]
PART II
The nature of body, nay, of substance in general, not being suffi
ciently known, had brought it about (a fact we have already touched
upon) that certain distinguished philosophers of our time, since they
placed the notion of body in extension alone, were compelled to have
recourse to God in order to explain the union between the soul and
the body, nay, also, the communication of bodies with each other.
For it must be confessed that it is impossible for a mere extension,
involving only geometrical notions, to be capable of action and
passion : and so this alone seemed to be left to them, that, when man
thinks and undertakes to move his arm, God, as it were, by a primeval
compact, moves his arm instead of he himself ; and on the other hand,
when the motion exists in the blood and spirits,2 God excites percep
tion in the mind. But these very things, since they are foreign to a
correct method of philosophizing, ought to admonish the authors that
they are resting upon a false principle, and that they have not assigned
rightly the notion of body, from which such things followed. We
have shown, therefore, that there is in every substance a force of
action and, if it is created, of passion also, that the notion of extension
is in itself not complete, but that a relation to something which is
extended, whose diffusion or continued replication it makes known,
and so the substance of a body is presupposed, which involves a power
of acting and resisting, and everywhere exists as a corporeal mass,
and the diffusion of this is involved in extension. Whence one day
we shall kindle a new light, also, for the explanation of the union of
the soul and the body. But now we must show how from thence
follow wonderful and extremely useful practical theorems, pertaining
to Dynamics, that is, the science which teaches the rules especially of
corporeal forces.
It must be known before all things that force, indeed, is some
thing truly real, even in created substances; but space, time, and
motion have something of a rational entity, and are true and real,
i Gerhardt, Leibniz, math. Schrift., II., 2 [Vol. <>]» pp. 246-254; aus d.
Manuscript, der Konigl. Biblioth. zu Hannover.
- Cf. Bacon's theory of the Spirit nx, a brief account of which is given by
Lasswitz, Gesch. <L AtomistiJc, 1. 4:51-432. — TR.
APPENDIX 685
not of themselves, but since they involve divine attributes, — im
mensity, eternity, operation, or the force of created substances. Hence
it already follows that there is no vacuum in space or time ; that
motion, moreover, separated from force, or where in it only the geo
metrical notions, — magnitude, figure, — and the variation of these
are considered, is in truth nothing else than a change of position, and
so motion, as far as (quoad} phenomena are concerned, consists in a mere
relation, which also Descartes acknowledged, when he defined transla
tion from the neighborhood of one body into the neighborhood of
another. But in deducing his consequences he forgot his definition,
and determined the rules of motions as if motion was something real
and absolute. So, therefore, we must consider, if an indefinite num
ber of bodies are in motion, that from the phenomena it cannot be
deduced in which of them absolute determinate motion or rest exists,
but to any one you please taken from these can be attributed rest,
provided that the same phenomena come forth. Hence it follows
(a result which Descartes did not notice) that the uniformity of the
hypotheses is changed neither by the encounters (concursus) of bodies with
each other; and besides, that such rules of motions must be assigned
that the respective nature of motion may remain intact, nor from the
event after the encounter can it be divined through the phenomena
where before the encounter there had been rest or determinate abso
lute motion. Whence the rule of Descartes does not at all accord
with the facts, by which he asserts that a body at rest can in no way
be driven from its place by another smaller body, and other things of
this sort. Than which nothing is more remote from the truth. It
follows, also, from the relative nature of motion, that the action of
bodies against each other by turns or percussion is the same, provided they
approach each other with the same velocity ; that is, the same appearance
remaining in the given phenomena, whatever at length be the true
hypothesis, or to whichever at length we rightly ascribe motion or
rest, the same event appears in the phenomena sought or resulting,
even in respect to the action of bodies among themselves. And this
also is what we find by experience (experimur), that we shall feel the
same pain, whether our hand runs against a stone at rest, suspended,
if you please, from a thread, or the stone with the same velocity runs
against our hand at rest. Meanwhile, we speak thus, according as
the thing demands, for a more suitable and simpler explanation of
the phenomena, precisely as in spherics we employ the motion of the
primum mobile, and in the theory of the planets we must use the
( -opernican hypothesis, so that already these disputes, urged on with
so much effort (in which even theologians were implicated), straight
way disappear. For although force is something real and absolute,
nevertheless motion pertains to the class of relative phenomena, and
truth is looked for not so much in phenomena as in causes.
686 LEIBNITZ'S CRITIQUE OF LOCKE
From our notions also of body and forces this principle arises, that
what happens in substance can be known to happen spontaneously and in
an orderly manner. With this is connected the principle that no
change takes place by a leap. This posited, it follows also that atoms
cannot be allowed. That we may seize the
jB force of this conclusion, let us assume
r\ that the bodies A and B (Fig. 6) meet
3B together and that }A comes to ZA, and
again ^B to 25, and thus meeting in 2A2B
are reflected from 2A to SA and from
2B to 3B. But supposing that atoms
exist, that is, bodies extremely hard and thus inflexible, it is evi
dent that the change takes place by a leap or momentary incre
ment (momentaneam)) for direct motion in the moment (momento)
itself of the encounter becomes retrograde unless we can assume that
immediately after the encounter the bodies rest, that is, lose their
force, which thing, besides the fact that it would otherwise be absurd,
would continue again the change by a leap, a momentary increment
(momenta/team), namely, from motion to
jA 0A|\/Y.B ^ i'est, and not however a transition by
I I "ML I/ O mtermediate steps. And so we must
A [ ~lA' ' ;£> know> if the bodies A and B (Fi8'- 7)
^ Xx" — * — meet and come from 1A1B into the place
JTIG 7 of concourse ,->A.,B, that there they are
gradually compressed like two inflated
balls, and more and more approach each other in turn by the con
tinually increased pressure ; that, moreover, by this thing the motion
itself is weakened, the force itself of the effort being carried over
into the elasticities (elastra) of the bodies, until at length they are
reduced to rest ; but then at length the elasticity of the bodies
restoring them, they themselves rebound from each other in turn
with a retrograde motion begun again from rest and continually
increasing ; at length with the same velocity with which they ap
proached each other, regained but turned in the opposite direction,
they recede in turn from each other and return into the positions
3A.J} which coincide with the positions 1A}B1 if the bodies are supposed
equal and of equal velocity. Thence it is already evident how no
change takes place by a leap, but the progress being gradually dimin
ished and at length reduced to rest, then at length a regress arises.
So that as from one figure another is not made (as from a circle an
oval) unless through innumerable intermediate figures, nor is there
any passing over from a place to a place or from a time to a time
unless through all intermediate places and times, so not from motion
is rest produced, and much less an opposite motion, unless through
all the intermediate degrees of motions. And since this principle
APPENDIX 687
is of so great consequence in nature, I wonder it is so little thought
of. From these considerations follows what Descartes had attacked
in his letters, and now also certain great men are unwilling to admit,
that all reflection arises from elasticity, and a reason is given of many
remarkable experiments which indicate that a body bends before it is
propelled, as Mariotte has very beautifully illustrated. Finally, that
especially wonderful principle follows from these considerations, that
no body is so poor but that it has elasticity, and so is pervaded by
a fluid still more subtile ; and then that there are no elements of bodies,
and that neither the most fluid matter nor certain solid globules of
the second element, exact and durable, are to be granted, but that
analysis proceeds to infinity.
It is consistent with this law of continuity, excluding leap from
change, that a case of rest can be considered as a special case of
motion, namely, as an evanescent or very small motion, and a case
of equality can be considered as a case of evanescent inequality.
Whence the consequence is, that such laws of motions must be
assigned that there be no need for peculiar rules for bodies equal
and at rest, but these rules spring from the rules of bodies unequal
and moving of themselves, or, if we wish to enounce peculiar rules
for rest and equality, we must be careful lest we assign such as (Jo
not agree with the hypothesis which considers rest as the last motion
or equality as the last inequality, otherwise we shall violate the
harmony of things and our rules will not agree among themselves.
This new system of testing our own or others' rules, T published first
in the "Xouvelles de la Republique des Lettres," July, 1687, article
S,1 and called it a general principle of order (principium ordinis gen
eral?), springing from the notion of the infinite and the continuum,
adding to it the axiom, that from orderly data the results also are
orderly (datis ordinatis etiam gucesita sunt ordinata). I expressed the
principle universally thus : If a case approaches a case continually in
the data and at length disappears in itself, the results of the cases must
also approach each other continually in the things sought for, and at length
cease in turn in themselves. (Si casus ad casum continue accedat in datis
tandemque in ipsum evanescat, necesse est ut etiam eventus casuum sibi con
tinue accedant in qucesitis tandemque in se invicem desinant.) Precisely
as in. geometry the case of the ellipse approaches continually the case
of the parabola, in proportion as one focus remaining another more
and more remote is regarded as assumed, until in the case of another
focus infinitely removed the ellipse passes into the parabola. Whence-
all the rules of the ellipse must be verified in the parabola (taken as
an ellipse whose other focus is infinitely distant). Whence the radii
falling parallel into a parabola can be conceived as coming from
1 Cf. Gerhardt, Leibniz, philos. Schrlft., 3, 51-55; Erdmann, 104-106.— TR.
088 LEIBNITZ'S CRITIQUE OF LOCKE
another focus or tending towards it. Since, therefore, in the same
way a case in which the body ^4 runs against B in motion can be
varied continually, so that the motion of A itself remaining, the
motion of B itself is regarded as less and less, until at length it is
regarded as disappearing in rest and thence again grows in the con
trary direction ; I say the result of the attack, but rebounding into
what whether in ..-I itself or in B itself, continually approaches by
both motions the result of the attack which exists in the case of B at
rest, and in it finally ceases ; and thus the case of rest both in the
data (in datis) and in the result or that which is sought (qucesitis) is
the limit of the cases of motion in a straight line, or the common
limit of direct and continuous motion, and thus as it were a special
example of either. With regard to this touchstone (lydium lapidcm),
brought over by me from geometry to physics, when I examined the
("artesian rules of motions, it happened, wonderful to say, that a cer
tain hiatus or leap showed itself utterly abhorrent to the nature of
things, for in expressing quantities by lines, and taking for abscissas
(pro ahscissis) the motions of B itself before the encounter, the data,
and for ordinates (pro ordinatim applicatis) the motion of the same
after the encounter, the results sought for, and by drawing the line
through the extremities of the ordinates (ordinatarum), according to
the precept of the rules of Descartes, this line was not a continuum,
but something wonderfully gaping and leaping in a certain absurd
and unthinkable manner. And when on that occasion I observed also
that the rules of Rev. Father Malebranche did not bear this examina
tion in all things, the distinguished man having considered the matter
again according to his candor, declared publicly that from this an
occasion had arisen for him to change his rules, for which reason,
also, he published a brief pamphlet. Although it must be confessed,
that because he had not yet directed his attention sufficiently to the
use of this new system, he has left something now also not yet suffi
ciently in all things complete (quadrant).
From what has been said, this wonderful principle also follows,
that the passion of every body is spontaneous, or arises from internal force,
although upon external occasion. I understand here, however, passion
proper, which arises from percussion, or which remains the same,
whatever hypothesis at length is assigned, or to whatever at length
we ascribe absolute rest or motion. For since the percussion is the
same, to whatever at length true motion corresponds, it follows that
the result of the percussion is distributed equally between both, and
thus both act equally in the encounter, and thus half the result arises
from the action of the one, the other half from the action of the other ;
and since half, also, of the result or passion is in one, half in the other,
it is sufficient that we derive the passion which is in one from the
action also which is in itself, and we need no influence of the one upon
APPENDIX 689
the other, although by the action of one an occasion is furnished the
other for producing a change in itself. Certainly, while A and />
meet, the resistance of the bodies, united with their elasticity, causes
them to be compressed because of the percussion, and the compression
is equal in each and according to whatever hypothesis, as the experi
ments show also, if any one conceives two inflated balls to meet, whether
both are in motion, or each is at rest, even if the one at rest be sus
pended from some thread, in order that it may most easily recede ;
for, always provided the velocity of approach or the respective velocity
be the same, the compression, or the intensity of the elasticity, will be
the same and equal in both. Then the balls A and B, restoring them
selves by the force of their own violent, namely, compressed and con
fined, elasticity, mutually repel each other by turns, and spread out,
as it were, in an arc, and, with a force equal on both sides, each is
driven back by the other, and so, not by the force of the other, but by
its own force, it recedes from that one. But what is to be understood
in the case of inflated balls is to be understood in the case of every
body so far as it is passive in percussion, namely, that the rebounding
and leaping apart arises from the elasticity in itself, that is, from the
motion of the permeating etherial fluid matter, and thus from force
internal, or proceeding from within. I understand, however, as I have
said, that the proper motion of bodies is separated from the common,
which can be ascribed to the centre of gravity ; whence their proper
motion is so to be conceived (to be conceived, I say, by the way of
hypothesis) as if they were produced on board a ship, which would
have the motion of their common centre of gravity, but they them
selves on board ship were so moved that from the composite common
motion of the ship or centre, and their own proper motion, the
phenomena are preserved. From what has been said, also, it is under
stood that the action of bodies is never without reaction, and both are equal
to each other, and directly contrary.
Since, then, only force, and thence nascent effort exists in any mo
ment (for motion never truly exists, as we have explained above),
and every effort tends in a straight line, it follows that all motion is
rectilinear, or composed of rectilinear,?. Hence, already it not only fol
lows that those bodies which, more in a curved line, try always to proceed
in the straight line tangent to it, but also, what any one least expects,
hence arises the true notion of stability (jirmitatis). For, it we suppose
that some one of those bodies which we call stable (although in truth
nothing is absolutely stable or fluid, but everything has a certain degree
of stability or fluidity, by us, however, it is named from a predominant
regard for our senses) circulates about its own centre, the parts will
attempt to fly away by the tangent, nay, they will really begin to fly
away; but since this separation of themselves from each other in turn
disturbs the motion of the encircling body, hence they are repelled, or
2 Y
LEIBNITZ'S CRITIQUE OF LOCKE
again crowded together towards themselves in turn, as if there were
iii the centre, a magnetic force of attraction, or as if there were in the
parts themselves a centripetal force, and therefore the revolution will
arise from the composition of the effort (nisu) to recede from the
rectilinear by the tangent and the centripetal effort (conatu). And
thus it remains that all curvilinear motion arises from the composition
among themselves of rectilinear efforts, and at the same time it is
understood that this crowding together by the encircling body is the
cause of all stability. Otherwise it could not be that all curvilinear
motion was composed of nothing but rectilinear motions. Whence,
also, again, we have a new and not less than before unexpected argu
ment against atoms. Moreover, nothing could be devised more incon
sistent with things than that stability be sought from rest, for (rue
rest never exists in bodies, nor from rest can anything arise but rest ;
but although A and B are mutually at rest with themselves, if not in
fact, at least relatively (although this never occurs exactly, for no body
preserves exactly the same distance from another, however small the tune),
and although whatever is once at rest will always be at rest unless a
new cause is added, nevertheless it does not follow, for this reason,
that because B resists the impelling body, it resists, also, the one
separating it from another, so that certainly, as the resistance of B
itself is overcome, or B itself driven forward, at the same time ,1
follows. But were the attraction, which is not given in nature, but
from the primitive stability (Jirmitate). explained through rest or
something similar, it -would assuredly follow. And so stability, also,
should not be explained unless by the crowding together produced by
the encircling body. For pressure alone does not sufficiently explain
the matter, as if the separation of B itself from A itself only is im
peded, but it is to be understood that in fact they separate from each
other in turn, that moreover one is again impelled to the other by the
encircling body, and thus, from the composition of the two motions,
this conservation of the conjunction is produced. And so those who
conceive in bodies certain tablets or insensible layers (for example, of
two polished marbles, which are exactly applied to eacli other), whose
separation is made difficult on account of the resistance of the ambient
body, and hence explain the stability of two sensible bodies, although
very often they speak truly, yet when they suppose some stability in
the layers again, they do not give the last reason for stability. From
these considerations, also, it can be understood why I cannot in this
thing continue (stare) in certain philosophic opinions of certain great
mathematicians, who, besides the fact that they admit vacant space.
and seem not to shrink back from attraction, consider motion, also,
as an absolute thing, and hasten to prove it from the revolution and
the centrifugal force which has thence arisen. But since the revolu
tion also arises only from the composition of rectilinear motions, it
APPENDIX 691
follows, if the equivalent of the hypotheses is sound in rectilinear
motions, however assumed, that it will be sound in the curvilinears.
From what has been said it can also be understood that the common
motion in many bodies does not change their actions among themselves, since
the velocity with which they approach each other in turn, and thus
the force of the encounter by which they act on each other in turn,
is not changed. Whence the remarkable experiments follow which
Gassendi mentions in his letters on motion impressed by a trans
ferred motor, that he might satisfy those who seemed to themselves
to be able to infer the rest of the earth's sphere from "the motion
of projectiles. Nevertheless, it is certain that, if any [persons] are
borne in a large ship (closed, if agreeable, or certainly so constituted
that the external phenomena cannot be observed by the travellers),
and if the ship is moved, although with great velocity, yet quietly or
uniformly, they themselves will have no principle by which to dis
tinguish (from those things, namely, which take place 011 shipboard)
whether the ship is at rest or moves, even if by chance they play ball
on the ship, or practice other movements. And this fact must be
noted in favor of those whose belief accords with the not rightly
understood notion of the Copernicans, that according to these, things
projected from the earth into the air are carried off (abripi) by the
air with the gyrating earth, and thus the motion of the bottom fol
lows, and fall back upon the earth just as if this were at rest ; a view
which is properly judged insufficient, since the very learned men who
make use of the Copernican hypothesis conceive, rather, that some
thing on the surface of the earth is moved with the earth, and, just
as if discharged from a bow or hurling machine (tormento), carries
with itself the impetus made by the gyration of the earth, together
with the impetus made by the projection. Thence, when their double
motion is the one common with the earth, the other peculiar to the
projection, it is no wonder that the common motion changes nothing.
Meanwhile, it is not to be disguised that, if the projectiles could be
driven so far, or if the ship were conceived so large, and borne with
such velocity, that before the descent the heavy earth or ship described
an arc perceptibly different from a straight line ; a distinction would
be discovered, because then, indeed, the motion of the earth or ship
(because circular) does not remain common to the motion which was
impressed upon the missile by the gyration of the ship or earth
(because rectilinear). And in the effort of heavy bodies towards the
centre, external action is added, which can no less produce a diversity
of phenomena, than if the compass were kept closed on the ship, which
would certainly indicate a variation of the ship. As often, however,
as the question concerns the equivalence of hypotheses, all things must
be united which concur in the phenomena. From these considera
tions, also, it is understood that any composition of motions or reso-
692 LEIBNITZ'S CRITIQUE OF LOCKE
lution, whatever, of one motion into two or more can safely be
employed, concerning which, nevertheless, a certain very clever man
in the works of Wallis had hesitated, not without reason. For the
matter certainly deserves proof, and cannot (as is done by many) be
assumed as in itself known.
VI
ON THE RADICAL ORIGIN OF THINGS1
November 23, 1097
[From the Lathi]
Besides the world or the aggregate of finite things, there is a
Unique Being who rules, not only as the mind in me, or rather as I
in my body rule myself, but also in a much higher manner. For
this unique sovereign of the universe not only rules the world, but
also frames or fashions it, and is superior to the world and, so to
speak, outside the world (extramundanum) , and thus is the ultimate
reason of things. For the sufficient reason of existence can be found
neither in any single thing, nor in the entire aggregate and series
of things. Let us suppose that there was an eternal book of the
Elements of Geometry, one copy always made from another, it is
evident that, although we can account for the present book by the
past, whence it has been copied, nevertheless wre never, by assuming
in the past as many books as we please, come to the complete reason,
for we may always wonder why, from all time, such books have
existed; that is to say. why these books were written, and why so
written. What is true of books is likewise true of the different states
of the world, for the following state has in a measure been copied
from the preceding (although according to certain laws of change),
and so to whatever extent you go back into anterior states, you will
never find in these states the full reason; that is to say, why any
world exists rather than none, and why such an one.
Therefore, although you imagine the world to be eternal, since,
nevertheless, you assume only a succession of states, and do not find
in any one of these whatever the sufficient reason, nay more, since by
assuming any number you please you do not advance even the least
towards accounting for them, it is evident that the reason must bf
sought elsewhere. For in eternal things we must understand that.
1 Gerhardt, Leibniz, philos. Schrift., 7, o02-;>08: Erdmanu, 147-150; Janet,
2, .">4(J-55:3 (in French) . — TR.
APPENDIX 693
even if there were no cause, yet there is a reason, which in persisting
things is the necessity itself or the essence ; but in a series of chang
ing things, if we suppose that this series proceeds from a prior series
eternally, the reason would be the prevalence of inclinations, as we
shall soon see, in which, that is to say, the reasons do not necessitate
(with an absolute or metaphysical necessity so as to imply the con
trary), but incline. From these considerations it is evident that we
cannot escape the ultimate extramundane reason of things or God
by assuming the eternity of the world.
The reasons therefore of the world lie concealed in something
outside the world, different from the chain of circumstances or series
of things, whose aggregate constitutes the world. We must then
come from physical or hypothetical necessity, which determines the
posterior states of the world from the prior states, to something which
ivS of absolute or metaphysical necessity, the reason for which cannot
be given. For the present world is physically or hypothetically but
not absolutely or metaphysically necessary. In fact, having assumed
that it is what it is, it follows that henceforth things must be what
they are. Since, therefore, the ultimate root must be in something
which is metaphysically necessary, and since there is no reason of
the existing unless from the existing, it is therefore necessary that
a unique being exist of metaphysical necessity, or whose essence is
existence, and that thus something exists different from the plurality
of beings or the world, which we have admitted and shown not to
be of metaphysical necessity.
But that we may explain a little more distinctly how temporal,
contingent or physical truths originate in eternal, or essential or
metaphysical truths, we must first know, that, by the very fact itself
that something rather than nothing exists, there is some demand
for existence in possible things or in possibility itself or essence, or
(so to speak) a stretching forth to existence, and, to sum it up in
a word, that essence per $e tends to existence. Whence it hereafter
follows, that all possible things, or those expressing essence or pos
sible reality, with equal right tend to essence (essentiam1) in pro
portion to the quantity of essence or reality, or in proportion to the
degree of perfection which they involve ; for perfection is nothing
else than quantity of essence.
Hut from this we see most clearly that from the infinite combina
tions of possible things and possible series there stands forth one
through which the greatest quantity of essence or possibility is
brought through to existence. There is always, in fact, in things a
1 The reading according to botli Gerhardt and Erdmann. Janet's French
version reads: " 1'existenee.'' The argument would seem to require the read
ing " existentium." — TR.
694 LEIBNITZ'S CRITIQUE OF LOCKE
principle of determination which is to be sought from the maximum
or minimum, so that beyond question the greatest effect is manifested
with, so to speak, the least expense. And here time, place, or, in a
word, the receptivity or capacity of the world can be considered as
the expense or ground upon which, as conveniently as possible, it
must be built, while the varieties of the forms correspond to the
proportion of the building and the number and elegance of the
rooms. And it is as in certain games when all the places at a table
must be rilled according to certain laws, where, unless you employ
a certain skill, hindered finally by the unfavorable places, you will
be compelled to leave vacant more places than you were able or
desired to do. There is, however, a certain method by which the
greatest possible space is most easily filled. If therefore, for instance,
we assume that it has been decreed that there be a triangle, though
with no other accidentally determining condition, the result is an
equilateral triangle ; and if it is assumed that we must proceed from
point to point, though nothing determines the road beyond, the
easiest and the shortest way will be chosen ; thus having once assumed j
that being prevails over non-being, or that there is a reason why/
something rather than nothing existed, or that from possibility aj
transition must be made to act, it follows hence, in the absence of
any further determination, that the quantity of existence is as great
as possible in proportion to the capacity of the time and place (or
the order of possible existence), just as tiles are so laid that in thes
proposed area as many as possible may be contained.
From these considerations we understand already in a wonderful
way how, in the very original formation of things, a certain Divine
Mathematics or Metaphysical Mechanics is employed, and the deter
mination of the greatest amount of existence has place. Thus the
right angle is the determinate of all the angles in Geometry, and
liquids placed in different media arrange themselves in the most
capacious form, namely, the spherical; but especially in general
Mechanics itself, when many heavy bodies struggle with each other,
such a motion at length arises, through which the greatest descent
on the whole is accomplished. For if all possibilities writh equal
right tend to existence according to the measure of reality, so all
weights by equal right tend to descend in proportion to the measure
of gravity, and as here the motion appears, in which is contained
the greatest possible descent of the heavy bodies, so there the world
appears, through which is realized the greatest possible production
of possibilities.
And so also we already have physical necessity from metaphysical :
for although the world is not metaphysically necessary, so that the
contrary implies contradiction or logical absurdity, it is nevertheless
physically necessary or determined so that the contrary implies
APPENDIX . 695
imperfection or moral absurdity. And as possibility is the source
of essence, so perfection or the degree of essence (through which
the greatest number of things are compossible) is the source of exist
ence. Whence it is at the same time evident how freedom exists in
the Author of the world, although he does all things determinately
because he acts from the principle of wisdom or perfection. Indif
ference certainly arises from ignorance, and the greater one's wisdom
the more he is determined to the most perfect.
But (you will say) this comparison of a certain determining meta
physical mechanism with the physical one of heavy bodies, although
it seems elegant, nevertheless is wanting in this because the struggling
heavy bodies truly exist, but the possibilities or essences before or
besides existence are imaginary or fictitious, therefore no reason of
existence can be sought in them. I reply that neither these essences
nor the eternal truths which they call from them are fictitious, but
exist in a certain so to speak region of ideas, namely in God himself,
the source of every essence and of the existence of the rest. That
we do not seem to have spoken gratuitously, the existence itself of
an actual series of things indicates. For since reason is not found
in this series, as we showed above, but must be sought in meta
physical necessities or eternal truths ; moreover, since existences
cannot exist unless from existences, as already we maintained above,
eternal truths must have existence in a certain absolute or meta
physically necessary subject, that is in God, through whom these
things, which otherwise would be imaginary, are (to speak barbar
ously but significantly) realized.
And in truth actually in the world we observe that all things take
place according to the laws of the eternal verities not only geomet
rical but also metaphysical, that is, not only according to material
necessities, but also according to formal reasons; and that is true
not only generally in that reason of the existing rather than non-
existing, and the so rather than otherwise existing world which we
have now explained (which certainly is to be sought from the tend
ency of possibilities to existence), but also by descending to specials
we see, by a wonderful plan in all nature, the metaphysical laws of
cause,. po\ver, action, have place, and these prevail over the purely
geometrical laws themselves of matter, as in giving the reasons of
the laws of motion I have observed to such an extent that I was
finally compelled to abandon, as elsewhere I have more at length ex
plained, the law of the geometrical composition of impulses (conatuum),
defended formerly by me, a youth, when I was more materialistic.
Thus, therefore, we have the ultimate reason of reality both of
essences and of existences in one, which assuredly greater, above and
before the world itself is necessarily existent, since through itself
not only existences, which the world embraces, but also possibilities,
t>9<> LEIBNITZ'S CRITIQUE OF LOCKE
have reality. But this can be sought only in one source on account
of the connection of all things with each other. It is evident, more
over, that from this source existing things continually spring forth
(promanare) and are produced and the products exist, since it is not
apparent why one state of the world rather than another, yesterday
rather than to-day, flows from itself. It is also evident how God acts
not only physically but also freely, and is in himself not only the
efficient but also the final cause of things, and how an account is
taken by him, not only of grandeur and power in the mechanism of
the universe already constituted, but also of goodness and wisdom
in that to be constituted.
And lest any one may think that moral perfection or goodness is
here confounded with metaphysical perfection or magnitude, and the
latter being granted may deny the former, it is to be understood that
it follows from what has been said, not only that the world is the
most perfect physically, or, if you prefer, metaphysically, or that
that series of things has been produced in which the greatest pos
sible reality is actually manifest, but also that it is the most perfect
morally, because in reality moral perfection in souls themselves is
physical. Whence the world is not only an especially admirable
mechanism, but also, as far as it is composed of souls, is the best
Republic, through which there is brought to souls the greatest pos
sible felicity or joy in which their physical perfection consists.
But, you will say, we experience the contrary in the world, for the
best very often fare the worst, the innocent, not only beasts, but also
men, are struck down, and even killed with torture ; finally, the world,
especially if the government of the human race be regarded, seems
rather a certain confused chaos than a thing arranged by a certain
supreme wisdom. So at first view I confess it seems, but the contrary
must be established by a more thorough inspection ; a priori, it is
evident from these very considerations which have been brought for
ward, that the highest possible perfection, namely, of all things, and
so also of mind, is obtained.
And in truth it is unjust to judge, unless after an investigation of
the whole law, as the jurisconsults say. We know a small part of the
eternity extending into immensity ; for how little is the memory of a
few thousands of years which history recounts for us. And yet, from
so small experience we judge rashly concerning the immense and the
eternal, as men in a prison, or, if you prefer, born and educated in
the subterranean salt-pits of the Sarmatians, thought that there is no
other light in the world but that dim lamp light scarcely sufficient
to direct their steps. We look at a very beautiful picture, we cover
this entirely, reserving a small portion ; what else in this will appear,
even if you look very attentively, nay, how much more will you observe
from near by thnn a certain confused congeries of colors without
APPENDIX 697
choice, without art; and nevertheless, when the whole covering is
removed, and you shall see the whole picture in the proper position,
you will know that that which seemed thoughtlessly spread upon the
canvas has been done with the highest art by the author of the work.
What the eyes observe in pictures, the ears perceive in music. Eminent
composers very often mix discords with concords in order to arouse,
and, as it were, sting the hearer, and as more solicitous concerning
the outcome, all having soon been restored to order, that he may
rejoice so much the more, in short, that we may take pleasure in
petty dangers or experiences of evils by the sense itself, or by the
display of either our power or happiness ; or, as we delight in the
spectacle of the rope-dancers, or in the sword-dance (saltatione inter
tjladios — sauts perilleux, Leibnitz), things that themselves excite terror,
and we, our very selves, half let down the children in sport, as it
were, now almost about to throw them before us, just as the ape
bore Christian, king of Denmark, when an infant, and wrapped in
swaddling clothes, to the roof of the house, and while all were anxious,
like one in sport bore him safe back again into his cradle. In accord
with the same principle, it is insipid always to eat sweet things ;
sharp, sour, nay more, bitter things which excite the taste, are to be
mixed with them. He who has not tasted the bitter, has not deserved,
nay more, will not appreciate the sweet. This itself is the law of joy,
that pleasure does not proceed uninterruptedly ; for this produces
disgust, and makes us inert, not joyful.
But what we have said of this part which can be disturbed while
the harmony on the whole is preserved is not so to be interpreted as
if no account is taken of the parts, or as if it would suffice that the
whole world be complete in its own parts, although it can happen
that the human race is wretched, and that there is no care for justice
in the universe, or account taken of us, as some think, who judge not
lightly enough concerning the totality of things. For we must know
that, as in the best constituted republic, care is taken that it be as
well as possible with individuals, so the universe would not be suffi
ciently perfect unless, while the harmony of the universe is preserved,
as much regard is had for particular interests. Of which thing no
better measure could be constituted than the law itself of justice,
saying that each should take part in the perfection of the universe,
and in happiness proper in proportion to the measure of his own
virtue and of that will which is a disposition of mind (affectus) toward l
the common good, by which that itself is completed which wre call the
affection and love of God, in which alone the force and also the power
of the Christian religion consists, in the judgment even of the wise
theologians'. Xor should it seem wonderful that so much is conferred
1 G"rhanlt roads, incorrectly, " eri^o *' : Enlntami, correct!; " erga" — TF.
LEIBNITZ'S CRITIQUE OF LOCKE
upon souls in the universe, since they very closely reproduce the image l
of the supreme author, and are related to him not only as machines to
the maker (like the rest), but also as citizens to the prince, and will
continue in existence equally with the universe itself, and express and
concentrate in a measure the whole in themselves, so that it can be
said that souls are the entire parts.
But as regards the sufferings especially of good men, it must cer
tainly be maintained that they result in their greater good, and that
is true not only theologically, but also physically, as the grain cast
into the earth suffers before it bears fruit. And on the whole, it can
be said that sufferings, temporarily evil, are in effect good, since they
are the short roads to greater perfection. So, in physics, those liquors
which ferment slowly are improved more slowly, but those in which
the fermentation is stronger are improved more readily, the parts
being thrown off with greater force. Arid this is, as you would say,
to go back, in order, by a greater effort, to leap forwards (qu'on recule,
pour inteux sauter, — you go back to take a better leap). These views,
therefore, must be maintained to be not only pleasing and comforting,
but also most true. And in general, I think there is nothing, both
truer than happiness, and more propitious and more delightful than
truth.
Respecting the increase also of the beauty and general perfection
of the divine works, a certain perpetual and very free progress of the
whole universe is to be recognized, so that it proceeds to ever greater
culture. As for instance, a great part of our earth receives culture
and will receive more and more. And although it is true that some
times some parts grow wild again or are destroyed and depreciated,
yet this must so be understood, as a little before we interpreted suf
fering, namely, that this destruction and depreciation itself is useful
in the attainment of something greater, so that in some measure we
gain by the very loss.
And as to the objection which might be made that thus the world
should long ago have been made a paradise, the reply is at hand :
although already many substances have attained great perfection,
nevertheless, on account of the divisibility of the continuum to infinity,
there always remain in the abyss of things parts hitherto asleep, to be
aroused and carried forwards to something- greater and better, and, in
a word, to a better culture. And accordingly, progress never comes
to an end.
1 Both Gerhardt and Erdmann read, " imagine " ; manifestly a typographi
cal error for " imaginem." — TB.
APPENDIX 699
VII
APPENDIX l
May, 1702
[From the Latin}
Up to the present time, I have published no book, indeed, against
the Cartesian philosophy, but often in the " Acta Eruditorum Lipsien-
sium " and the " Journaux " of France and Holland hastily-thrown-off
productions (Schediasmata) will be found inserted by me, in which I
have borne witness to my dissent from it. But first (not to speak
now of the others), about the nature of the body and what motive
forces are in the body ; in all others my opinion was the same. The
Cartesians, it is true, place the essence of body in extension alone, but
I, although with Aristotle and Descartes against Democritus and Gas-
sendi I admit no vacuum, and against Aristotle with Democritus and
Descartes think there is nothing but an apparent rarefaction and con
densation, yet I think with Democritus and Aristotle against Des
cartes, that there is something passive in body besides extension, that,
namely, by which body resists penetration ; but besides this, I also
recognize with Plato and Aristotle against Democritus and Descartes
an active force or ej/reA.e;(€ia, so that I think Aristotle so far rightly
defined nature as the source ( principiuni) of motion and rest, not
because I think any body, unless already in motion, can be moved by
itself or be put in motion by any quality such as gravity, but because
I think every body always has implanted in it motive force (motricem),
nay. rather motion actually intrinsic (motum intrinscum actualem), from
the very beginning of things. Moreover, I agree with Democritus and
Descartes against the multitude of the Scholastics, that the exercise of
the motive (motricis) power and the phenomena of bodies can always
be explained mechanically, the causes themselves of the laws of motion
being withdrawn which spring from a higher source, namely, from the
entelechy, which cannot be derived from the passive mass alone and
its modifications.
But in order that my opinion may be better understood and its
reasons also may be somewhat apparent, I think, in the first place,
that the nature of body does not consist in extension alone, because
in evolving the notion of extension we must notice that it is relative
to something that is extended and signifies a diffusion or repetition
1 Gerhardt, Leibniz, math. Schrift., II, 2 [Vol. (>], 98-106; Gerhardt, Leibniz,
philos. Schrift., 4, 393-400; cf. G.'s Einleitung, ibid., 271-272. The letter to
Honoratus Fabri, and this Appendix, were printed by Gerhardt from the Ms.
in the Royal Library at Hanover.
700 LEIBNITZ'S CRITIQUE OF LOCKE
of a certain nature. For every repetition (or multitude of the same
tilings) is either discrete, as in numbers where aggregate parts are
discerned; or is continuous, where the parts are indeterminate and
can be assumed in infinite ways. Continwi, however, are of two kinds ;
the one successive, as time and motion, the other simultaneous or
consisting of coexisting parts, as space and body. And as in time
we conceive nothing else than the disposition or series itself of varia
tions, which can occur in itself, so in space we perceive nothing
else than the possible disposition of bodies. And so when space is
said to be extended, we accept the statement in the same sense as
when time is said to endure or number to be numbered; for, in
truth, time adds nothing to duration nor space to extension, but as
successive variations are in time, in body those things are diverse
which can be diffused. For, because extension is a simultaneous
continuous repetition as duration is a successive one, as often as the
same nature is diffused at the same time through many things, as
ductility or specific gravity or the yellow-color in gold or the white-
color in milk, extension is said to have place generally in body as
resistance or impenetrability, although it must be confessed that that
diffusion continuous in color, weight, ductility, and things similar in
kind but homogeneous, is only apparent and has no place in parts
however small, and so the extension of resistance alone which is
diffused through matter preserves this name with the strict investi
gator. But it is evident from these considerations, that extension is
not an absolute predicate, but relative to that which is extended or
diffused, and from the nature of which, diffusion can just as little be
separated as number from the thing numbered. And hence those
who assumed extension as an absolute primitive attribute, indefinable
and apprjTov, erred by defect of analysis and took refuge in the
occult qualities which for the rest they so despised, as if extension
were something that cannot be explained.
The question now is asked, What is that nature whose diffusion
constitutes body? We have already said that matter is constituted
by the diffusion of resistance; but since in our opinion there is some
thing else in body besides matter, the question is asked in what its
nature consists. We say, therefore, it can consist in nothing else
than ly TO) Svra/xiKw or the indwelling principle of change and per
sistence. Whence also it uses the physical doctrine of the two mathe
matical sciences to whose principles it was subordinated, geometry
and dynamics, the elements of which latter science not yet sufficiently
propounded, I have elsewhere promised. Moreover, geometry itself,
or the science of extension, again is subordinated to arithmetic, be
cause in extension, as I said above, there is repetition or multitude,
and dynamics is subordinated to metaphysic which treats of cause
and effect.
APPENDIX 701
Again, TO Swa/uKo? or power in body is twofold, — passive and active.
Passive power properly constitutes matter or mass, active ei/TcA^eio.
or form. Passive power is the resistance itself by which body resists
not only penetration but also motion, and by which it happens that
another body cannot enter into its place unless itself yields, but
itself does not yield unless by retarding somewhat the motion of the
impelling body, and so it attempts to continue steadfastly in its
former state, not merely that it may not depart thence voluntarily,
but also that it may resist change. And so there are therein two
resistances or masses : the first antitypy, as they call it, or impenetra
bility ; the second resistance, or what Kepler calls the natural inertia
of bodies, which Descartes also somewhere in his letters acknowledged,
from the fact that bodies certainly receive no new motion unless by
force, and so resist the impression and break its force. This would
not happen if there were not in the body, besides extension, TO Bvva-
fjuKov or the principle of the laws of motion, by which it happens that
the quantity of forces cannot be increased, nor can a body even be
impelled by another unless its ow7n force is broken. This passive force
in the body, moreover, is everywhere the same and proportional to
its magnitude. For although some bodies appear more dense than
others, this nevertheless happens because their pores are more filled
with matter pertaining to the body, while, on the contrary, the rarer
bodies have the nature of a sponge, so that another more subtile
matter glides through their pores which is not reckoned with the
body nor its motion followed or looked for.
Active force, which also absolutely is customarily called force, is
not to be conceived as a simple common power of the schools, or as a
receptivitv of action, but involves a conatus or tendency to action, so
that, unless something else hinders, action follows. And in this
properly consists evTeXe^eta, too little understood by the schools ; for
such a power involves act (actum), and does not persist in a naked
faculty, although it does not always proceed wholly to the action
(actionein) to which it tends, as often, namely, as an impediment is
thrown in its way. Again active force is twofold, — primitive and deri
vative ; that is, either substantial or accidental. Primitive active force,
which is called by Aristotle eVTeAe^eta 17 TrpwT?/, generally the form of
substance (forma substantice), is another natural principle which with
material or passive power completes the corporeal substance, which is,
forsooth, a unum per se, not a mere aggregate of many substances; for
there is much difference, for example, between an animal and a flock.
And so this entelechy or soul, or something analogous to the soul,
exists, and always naturally actuates some organic body, which itself
separately assumed (quod ipsum separatim sumtum), when the soul is
separated forsooth or removed, is not one substance, but an aggregate
of many ; in a word, a natural machine.
702 LEIBNITZ'S CRITIQUE OF LOCKE
This natural machine, moreover, has this highest prerogative as
compared with an artificial, that exhibiting a proof of a divine author,
it consists of infinite organs wrapped up in itself, and so can never be
utterly destroyed, just as it cannot be absolutely produced, but can
be diminished only and increased, and be involved and evolved, this
being to a certain extent itself a substance, and in it (however trans
formed) a certain degree of vitality, or, if you prefer, of primitive
activity being always preserved. For what is said of animate things
must also be said proportionally of those which are not properly ani
mals. Meanwhile, it must be maintained -that intelligences, or the
more noble souls which are also called spirits, are ruled by God not
only as machines, but also as subjects, and are not liable to those
changes to which other living beings are exposed.
Derivative force is that which some call impetus, aconatus evidently
or tendency, so to speak, to a certain determinate motion, by which
accordingly primitive force or the principle of action is modified. I
have shown that this is not preserved the same in the same body, but
yet, however distributed in many, it remains the same in the amount
and differs from motion itself, whose quantity is not preserved. And
this itself also is the impression which a body receives by impulse, by
whose aid projectiles continue their motion and do not need any new
impulse, which Gassendi also has illustrated by elegant experiments
made on shipboard. Thus also some incorrectly think that projectiles
have their motion continued by the air. Further, derivative force
differs from action only as the instantaneous from the successive; for
there is already force in the first instant, but action requires a period
of time, and so is brought to pass by the prolongation of forces in
time, which is perceived in any part of the body whatever. And so
action is in reason composed of body, time, and force (y«V) or energy
(virtutis), since by the Cartesians the quantity of motion is estimated
by the calculation of velocity in the body, and forces are considered
far otherwise than as velocities, as will soon be stated.
To place active force in bodies moreover, many things compel us,
and especially the experience itself, which shows that motions are in
matter, although these motions must be attributed originally to the
general cause of things, — God; immediately, however, and specifically,
they must be attributed to the force placed in things by God. For to
say that God in creation has given to bodies a law of action, is nothing
unless he has given at the same time something by which the law is
observed ; otherwise he himself will be obliged always to procure in
an extraordinary manner the observance of the law. Yea, rather his
law is efficacious, and makes bodies efficient; i.e. he gave to them
natural (insitam) force. Further, we must consider that derived force
and action is a certain mode (modale), since it admits change. Hut
every mode is constituted by some modification of something persist-
APPENDIX 703
ing or more absolute. And just as figure is a certain limitation or
modification of passive force or extended mass, so derivative force and
moving action (actio matrix) is a certain modification not certainly of
a thing merely passive (otherwise a modification or limit would involve
more reality than the thing itself which is limited), but of something-
active, that is, of the primitive entelechy. Therefore, derivative and
accidental or changeable force will be a certain modification of the
primitive energy (virtutis) essential to and abiding in every corporeal
substance. Whence the Cartesians, since they acknowledge no active
principle substantial and capable of modification in the body, are
compelled themselves to reject (abjudicare) all action, and to trans
fer it to God alone, a far-fetched mechanical view (accersitum ex
Machina), which is not philosophical.
But primitive force is changed by derivative in the impacts of
bodies, according as the exercise of primitive force, is turned within
or without. For in truth, every body has an internal motion, nor can
it ever be brought to rest. This internal force, again, turns itself with
out, when it performs the duty of elastic force, when, namely, internal
motion is impeded in its accustomed course, whence every body is
essentially elastic, water not even excepted, and how violently this
rebounds, even the cannon balls (piles tormentarice) show. And
unless every body were elastic, the laws of motions could not be
proved true and binding. Meanwhile this force does not always
render itself conspicuous in the sensible parts themselves of bodies,
since these manifestly do not sufficiently cohere. But the harder a
body is, the more elastic it is and the more strongly it rebounds.
Indeed in impact, when bodies mutually rebound from each other,
this occurs through elastic force, whence indeed bodies always have
their own special motion from impact by their own special force, to
which a foreign impulse furnishes only an occasion of acting, and, so
to speak, a determination.
Hence, moreover, we understand that, although that primitive
force or form of substance (which, it is true, determines even the
forms in matter, while it produces motion) is admitted, yet in ex
plaining elastic force and other phenomena we must always proceed
mechanically, certainly by the forms which are modifications of
matter and by impulses which are modifications of form. And it is
useless, when distinct and specific reasons should be given, to have
recourse immediately and in general (f/enerice) to form or primitive
force in a thing, as it is useless in explaining the phenomena of created
things to recur to the first substance or God, unless his means or ends
are at the same time specifically explained, and the proximate efficient
or even the special final causes are rightly assigned, so that his power
and wisdom appear. For in general (whatever Descartes may have
said), not only efficient, but also final causes, belong to physical dis-
704 LEIBNITZ'S CRITIQUE OF LOCKE
cussion (traciationis) ; precisely as a house is badly exhibited, if any of
its parts betrays its structure only, not its use. L have further already
pointed- out above that, since we affirm that all things in nature are
explained mechanically, the reasons themselves of the laws of motion
or the principles of mechanics must be excepted, which should be
deduced not from mathematics alone and the imagination of the sub
ject, but from a metaphysical source, namely, from the equality of
cause and effect, and from other laws of this kind which are essential
to entelechies. Certainly, as has already been said, physics is subor
dinate through geometry to arithmetic, through dynamics to meta
physics.
But the Cartesians, not sufficiently understanding the nature of
forces, confounding motive force with motion, have seriously erred
in determining the laws of motions. For although Descartes knew
that the same force must be preserved in nature, and that a body,
although he attributed a part of its force (namely, the derivative)
to another, so retains a part that the sum of the forces remains the
same, (yet), deceived by the example of equilibrium or dead force
as T call it (which here does not enter into the reckoning, and of
living force or of that which is now in question, it is only an infini
tesimal part), (he) believed that force exists in a composite system
(rat lone composita) of masses and velocities, or that it is the same as
that which he calls quantity of 'motion, by which term he under
stands the product of the mass into the velocity (ex ductu massa in
celeritatem), when, nevertheless, it has elsewhere been demonstrated
by me a priori that forces exist in a composite system of simple
masses and double velocities. I know that lately certain learned
men, when at length they were compelled to admit against the
Cartesians that the same quantity of motion is not preserved in
nature, and considered this too alone as absolute force, concluded
that this force also does not abide, and took refuge in the conserva
tion alone of relative (respectivce) force, but we have discovered that
not in the conservation of absolute force even has nature been
mindful of her own constancy and perfection. And the opinion
of the Cartesians indeed, in which the quantity of motion is pre
served, contradicts all the phenomena, (while) ours is wonderfully
confirmed by experiments.
The Cartesians err, also, in this, because they think that changes
occur by a leap (per salt urn) ; as if, for example, a body at rest can in
a moment pass over into a state of determined motion, or as if a body
placed in motion can suddenly be brought back to rest, not by passing-
through the intermediate grades of velocity, because they have plainly
not understood the use of elastic force in the concourse of bodies.
Which, if it were absent, I confess that neither the law which I call
the law of continuity would be observed in things, through which
APPKMMX 705
leaps are avoided, nor the law of equivalence by which absolute forces
are conserved, nor other excellent inventions of nature's architect
have place, by which the necessity of matter arid the beauty of form
are united. Moreover, the elastic force itself implanted in every bodv
shows that there is in every body, also, internal motion and infinite
(so to speak) primitive force, although in the impact itself, wrhen
circumstances demand, it is determined by derivative force. [For, as
in an arch, any part whatever sustains the entire weight, or in a tense
cord the traction, and any portion whatever of compressed air, has as
much force as the weight of the air pressing upon it, so any corpuscle
whatever, of the entire ambient (ambientis) mass is solicited to action
by the conspiring force, and awaits nothing but an occasion for exer
cising its power, as is shown by the example of gunpowder (/ndt-pri*
pyrii)'].
There are many other things in which I have been obliged to de
part from Descartes, but those which I have now brought forth relate
chiefly to the principles themselves of corporeal substances, and, if you
interpret them rightly, are capable of vindicating the ancient philos
ophy of a healthier school, which I see deserted by many of the
more recent scholars, even those well disposed towards it, where there
was no 'need. The philosophy of Rev. Father Ptolemams,1 a man
very versed in the principles of the ancients and the moderns, whose
remarkable teaching I examined myself, at Rome (from which philos
ophy I promise myself very much), has not yet reached us.
In a note, Leibnitz has added : In addition, T am pleased to state,
that although very many Cartesians boldly reject forms and forces in
bodies, Descartes nevertheless spoke more rnoderatelv, and professed
this only, that he found no reason for using them. I indeed admit
that they should be rejected if of no use; but in this very thing 1
have shown that Descartes has erred. For not only in eutelechies, or
TO) Swa/ziKu), are placed the principles of mechanism, by which all
things are regulated in bodies, but I have also shown in the " Acta
Eruditorum," '2 when T was replying to the very celebrated man, John
Christopher Sturm,3 who attacked, in his " Physica Eclectica," my iu-
1 Giovanni Battista Tolomei, 1653-1726, was acquainted with aU the Euro
pean languages and had a very extensive knowledge of all the sciences of his
time, and was reputed a profound theologian and skilful critic. Among his
works was Philosophia mentis et senstiii'nt, Rompe, 1696, fol., Augusta1 Vin-
delicorum, 1698, fol. — TR.
- Sept. 1698. The piece is the De ipsa natura, cf. Gerhardt, Leibniz, p/iilox.
Schrift., 4.504-516: Erdmann, 154-160; Jacques (in French), 1,455-468: Janet
(in French), 2, 553-567 ; transl., Duncan, 112-126. Cf. also Gerhardt's Kinlei-
txiifj, op. cit., 4, 417. — TR.
3 Johaim Christoph Sturm, 1635-1703, was, from 1669, Professor of Mathe
matics and Physics at the University of Altdorf. His Physica Eclectica
appeared at Nuremburg, 1697, 4to. While not celebrated for physical dis-
2 /.
(06 LEIBNITZ'S CRITIQUE OF LOCKE
sufficiently understood doctrine, with irrefragable demonstration that,
completeness being assumed, if there were nothing in matter but mass
itself and arrangement of its parts, it would be impossible for any
perceptible variation whatever to occur, since equivalences are substi
tuted for limits, and by banishing conatus, or the force of tendency,
to the future (the entelechies, that is, being removed), the state of
things present at one moment cannot be distinguished from the state
at any other moment. And I think Aristotle perceived this when he
saw that, besides local motion, change is necessary in order to satisfy
the phenomena. But changes, although in appearance manifold, just
as qualities, are reduced in the last analysis to variation alone of forces.
For all the qualities of bodies, that is, all their real stable accidents,
except forms (that is, those which do not exist in transition, as motion,
but are known as present, although referred to the future), are at
length, when analysis is set up, reduced to forces. Further, when
forces are removed, nothing real remains in motion itself, for from
variation alone of arrangement it cannot be determined where the
true motion or the cause of variation is.
VIII
LETTER OF LEIBXITZ TO BASXAGE DE BEAUVAL,
EDITOR OF THE "HISTOIRE DES OUTRAGES DES
SAVANTS," PRINTED IX THAT JOURNAL, JULY, 1698,
pp. 329 -sv/.1
Explanation of the difficulties which M. Bayle has found in the X?w
System of the Union of the Soul and the Body
[From the French]
1 take the liberty, Sir, to send you this explanation of the diffi
culties which M. Bayle has found in the hypothesis which I have
proposed in order to explain the union of the soul and the body.
Nothing is kinder than the manner which he has used towards me,
and I consider myself honored by the objections he has placed in
his excellent Dictionary, in the article Rorarius. Moreover, a mind
as great and as profound as his cannot make them without instruct
ing, and I shall try to profit by the light which he has shed upon
ooveries, he emphasized the method of experiment, and spread abroad a taste
for experimenting. Germany is said to owe to him the introduction of the
teaching of mathematics into the gymnasia and the common schools. — TR.
1 Cf. Gerhardt, Leibniz, philos. Schrift., 4, 517-524, cf. G.'sEinleitung, ibid.,
419; Erdmann, Leibnit. op. philos., 150-154; Jacques, (Euvres cle Leibniz, 1,
481-487; Dntens, Leibvit. op. out., 2, Pt. I., 74-79.
APPENDIX 707
these matters in this part as well as in many other parts of his work.
He does not reject what I had said of the conservation of the soul
and also of the animal, but he does not yet appear satisfied with the
manner in which I have claimed to explain the union and the inter
course of the soul and the body in the " Journal des Savants " of June
27 and of July 4, 1695, and in the " Histoire des ouvrages des savants/'
February, 1696, pp. 274, 275.
Here are his words, which seem to indicate wherein he has found
difficulty : " I cannot understand," he says, " the series of actions,
internal and spontaneous, which would cause the soul of a dog to
feel pain immediately after having felt joy, although it were alone in
the universe." ' I reply that when I said that the soul, although only
(Jod and it should exist in the world, would feel all that it now
feels, 1 only employed a fiction in supposing that which cannot happen
naturally, in order to show that the feelings of the soul are only a
consequence of that which is already in it. I know not whether the
proof of incomprehensibility which M. Bayle finds in this series must
be sought alone in that which he calls lower, or whether he wished
to introduce it from this time by the example of the spontaneous pas
sage from joy to pain ; perhaps, by wishing to throw out a hint that
this passage is contrary to the axiom which teaches us that a thing
always continues in the state in which it is once if nothing occurs
which obliges it to change, and that thus the animal having once joy
will always have it if it is alone or if nothing external makes it pass
to pain ; in every case I agree with the axiom, and, further, I main
tain that it is in my favor, as in fact it is one of my grounds. Is it
not true that from this axiom we conclude, not only that a body at
rest will always be at rest, but also that a body which is in motion
will always preserve this motion or change, that is to say, the same
volocity and the same direction, if nothing occurs to hinder it ? Thus
a thing does not remain only so long as it depends upon itself (d'elle)
in the state in which it is; but also when this is a state of change,
it continues to change, following always one and the same law. Xow
it is, according to my view, the nature of created substance to change
continually according to a certain order wrhich conducts it spontane
ously (if I may avail myself of this word) through all the states
which will happen to it, so that he who sees all, sees in its present
state all its past and future states. And this law of order, which con
stitutes the individuality of each particular substance, has an exact
relation to that which happens in every substance and in the entire
universe. Perhaps I do not make too bold a statement if I say that
I can demonstrate all this, but at present the question is only of
maintaining it as a possible hypothesis suitable for explaining the
phenomena. Now in this way the law of the change of the substance
of the animal bears it from joy to pain at the moment that a continu-
708 LEIBNITZ'S CRITIQUE OF LOCKE
ous solution is made in its body, because the law of the indivisible
substance of this animal is to represent what is done in its body in
the way that we experience it, and also to represent in some fashion
and in relation to this body all that is done in the world; the unities
of substance being nothing else than different concentrations of the
universe represented according to the different points of view which
distinguish them.
M. Bayle continues : u 1 understand why a dog passes immediatelv
from pleasure to pain when, being very hungry, and eating bread,
we give him a blow with a stick." T do not know whether we
understand it sufficiently. No one knows better than M. Bayle him
self, that it is in this that the great difficulty consists of explaining
why that which passes in the body produces a change in the soul, and
that it is this which has forced the defenders of occasional causes to
recur to the care which God must take to represent continually to the
soul the changes which take place in the body ; whilst 1 believe that
it is the nature itself which God has given it to represent in virtue of
its own laws what passes in the organs. He continues :
"But that his soul is constructed in such a way that at the moment
he is struck he would feel the pain, although we should not strike
him, although he should continue to eat the bread undisturbed and
unhindered, this is what I cannot understand." I do not remember.
also, to have said it, and we could say it only by a metaphysical fiction,
as when we suppose that God annihilates a body in order to produce
a vacuum, both being equally contrary to the order of things. For
since the nature of the soul was made at first in a manner suited to
represent successively the changes of matter, the case wre suppose
cannot happen in the natural order. God could give to each substance
its phenomena independent of those of others ; but in this way he
would have made, so to speak, as many worlds without connection as
there are substances ; almost, as we say, that when we dream we are
in a world apart, and that we enter into the common world when we
awake. It is not that the dreams are unrelated to the organs and th«
(rest of the body, but that they are related in a manner less distinct.
Let us continue with M. Bayle :
"T find, also," says he, "the spontaneity of this soul very incompati
ble with the feelings of pain, and, in general, with all the perceptions
which are displeasing to it." This incomprehensibility would be cer
tain, if spontaneous and voluntary were the same thing. Everything
voluntary is spontaneous; but there are spontaneous actions which
are without choice, and consequently are riot voluntary. It does not
depend upon the soul, always, to procure feelings which please it.
since the feelings it will have depend upon those which it has had.
M. Bayle proceeds :
" Moreover, the reason why this clever man does not approve the
APPENDIX 709
Cartesian system appears to me to be a false supposition : for it cannot
be said that the system of occasional causes makes the action of God
intervene by a miracle (Deum ex machina) in the reciprocal dependence
of the body and sonl ; for, as God intervenes only according to general
laws, he does not act there in an extraordinary way." It is not for
this reason alone that I do not approve of the Cartesian system ; and
if you consider mine a little, you see clearly that I find in itself that
which leads me to embrace it. Moreover, if the hypothesis of occa
sional causes should not need miracle, it seems that mine would not
cease to have other advantages. I have said that we may imagine
three systems to explain the intercourse we find between the soul and
the body; namely, first, the system of the influence of the one upon
the other, which is that of the schools taken in the common sense,
which I believe impossible, after the Cartesians; second, that of a
perpetual overseer, who represents in the one that which takes place
in the other, very much as if a man were charged with making two
.bad clocks always to agree, which of themselves would not be capable
of agreeing, and this is the system of occasional causes; and third,
that of the natural agreement of two substances such as would exist
between two very accurate clocks; and I find this as possible as the
system of the overseer, and more worthy of the author of these sub
stances, clocks or automata. But let us see whether the system of
occasional causes does not in reality suppose a perpetual miracle.
They say here, no, because God would act according to this system
only through general laws. I agree, but, in my opinion, that is not
sufficient in order to remove the miracles : if God did it continually,
they would not cease to be miracles, taking this word not popularly.
as a thing rare and wonderful, but philosophically, as that which
exceeds the forces of created beings. It is not sufficient to say that
God has made a general law; for, besides the decree, there must also
be a natural means of executing it; that is to say. what takes place
must be capable of being explained by the nature which God gives to
things. The laws of nature are not so arbitrary or so indifferent as
many think. If God decreed, for example, that all bodies should
have a tendency toward a circular line, and that the radii of the circles
should be proportional to the size of the bodies, it would be necessary
to say that there is a means of executing this decree by more simple
laws, or rather, it would be necessary to admit that God will execute
it miraculously, or at least by angels expressly charged with this care,
very nearly like those who were sometimes given to the celestial
spheres. It would btfthe same if some one said that God has given
to the bodies natural and primitive gravities by which each should
tend to the centre of its globe, without being pushed by other bodies ;
for in my opinion this system would need a perpetual miracle, o»- at
least the assistance of the angels.
710 LEIBNITZ'S CRITIQUE OF LOCKE
•k Does the internal and active property communicated to the forms
of bodies know the series of actions it is to produce ? JCot at all ; for
we know by experience that we are ignorant that we have in an hour
such or such perceptions." I reply that this property, or rather this
soul or form, does not know them distinctly, but that it feels them
confusedly. There is in each substance traces of all which has hap
pened to it and of all which will happen to it. But this infinite mul
titude of perceptions hinders us in distinguishing them ; as when I
hear a great confused noise of a whole people, I do not distinguish
one voice from another.
"It would be necessary, then, that the forms be directed by some
external principle in the production of their acts ; would not this be
the Deux ex machina, just the same as in the system of occasional
causes?" The preceding reply puts a stop to this inference. On the
contrary, the present state of each substance is a natural result of its
preceding state ; but there is only one infinite intelligence therein
which can see this result, for it envelops the universe in souls as well
as in each portion of matter.
M. Bayle concludes with these words : '• Finally, as he supposes
with much reason that all souls are simple and indivisible, we cannot
understand how they can be compared to a pendulum, that is to say,
that by their original constitution they can diversify their operations,
by availing themselves of the spontaneous activity which they would
receive from their Creator. We conceive clearly that a simple being-
will always act uniformly, if no foreign cause turns it aside. If it
were composed of many pieces, as a machine, it would act diversely,
because the particular activity of each piece might change at every
moment the course of that of the others ; but in a single substance,
where will you find the cause of the change of operation ? " I find
that this objection is worthy of M. Bayle. and that it belongs to those
which most deserve to be cleared up. But I also think that if I had
not provided for it at first, my system would not deserve to be ex
amined. I have compared the soul to a pendulum only in regard to
the regulated precision of its changes, which is indeed but imperfect
in the best clocks, but which is perfect in the works of God ; and we
may say that the soul is an immaterial automaton of the most accurate
kind. When it is said that a simple being will always act uniformly,
there is a distinction to be made, if 1o act uniformly is to follow per
petually one and the same law of order or of continuity, as in a cer
tain rank or series of numbers, I admit that every simple being itself,
and indeed every complex being acts uniformly; but if uniformly
means likewise, I do not agree. To explain the difference of this
sense by a.n example, a movement in a parabolic line is uniform in
the first sense ; but it is not so in the second, the portions of the para
bolic line not being' similar among themselves like those of the straight
APPENDIX 711
lines. It is true, to mention it in passing, that a simple body left to
itself describes only straight lines, if we speak only of the centre
which represents the motion of this entire body; but when a simple
and rigid body, having once received a turbination or circulation
around its centre, retains it in the same sense and with the same velo
city, it follows that a body left to itself may describe circular lines by
its points distant from the centre, when the centre is at rest, and even
certain quadratrices, when this centre is in motion, which have the
ordinate composed of the straight line running through the centre,
and of the right sine whose versed sine is the abscissa, the area being
to the circumference as this straight line is to a given straight line.
We must consider also that the soul, wholly simple as it is, has always
a feeling composed of many perceptions at once, which fact effects
as much for our purpose as if it were composed of pieces like a
machine. For each preceding perception influences the following,
conformably to a law of order which exists in perceptions as in move
ments. Thus the majority of philosophers, for many centuries, who
allow thoughts to souls and to angels, which they believe destitute of
all body, to say nothing of the intelligences of Aristotle, admit a
spontaneous change in a simple being. I add that since the percep
tions which are found together in one and the same soul, at the same
time, involve a multitude veritably infinite of minute indistinguishable
feelings as the sequel must develop, we must not be astonished at the
infinite variety of that which must result therefrom in time. All this
is only a consequence of the representative nature of the soul, which
must express what passes and indeed what will pass in its body, and
in some fashion in all others, through the connection or correspon
dence of all parts of the world. Tt would perhaps suffice to say that
God, having made atoms corporeal, might also well have made them
immaterial to represent the first; but we have thought it would be
well to dwell upon it a little more.
For the rest, I have read with pleasure what M. Bayle says in the
article Zeno. It might, perhaps, be perceived that what can be drawn
therefrom agrees better with my system than with every other, for
w^hat there is of reality in extension and motion consists only in the
ground of the order and the regulated series of phenomena and per
ceptions. In like manner, as many academicians and sceptics as
those who wish to reply to them, seem to be embarrassed principally
only because they sought a greater reality in sensible things outside
of us than that of the regulated phenomena. We conceive extension
in conceiving an order in coexistences, but we must not conceive
it any more than space, after the fashion of a substance. Tt is like
time, which presents to the mind only an order in changes. And as
for motion, what is real therein is the force or the power ; that is to
say, what there is in the present state which carries with itself a
LEIBNITZ'S CRITIQUE OF LOCKE
change for the future. The rest is only phenomena and relations.
The consideration of this system shows also that, when we enter into
the heart of things, we find more reason than we thought in the
majority of the philosophic sects. The little substantial reality of
the sensible things of the Sceptics: the reduction of all to harmonies
or numbers, ideas, and perceptions of the Pythagoreans and Platon-
ists ; the one and also the all of Parmenides and of Plotinus without
any Spinozism ; the Stoic connection, compatible with the spontaneity
of the others ; the vital philosophy of the Kabbalists and Hermetics
who put feeling above everything; the forms and entelechies of
Aristotle and the Scholastics, and even the mechanical explanation
of all particular phenomena, according to Democritus and the moderns,
and so forth, find themselves reunited as in a centre of perspective,
whence the object, obscured in regarding it from an entirely different
point, shows its regularity and the agreement of its parts ; we have
failed through a sectarian spirit in limiting ourselves by the rejection
of others. The formalist philosophers blame the material or cor-
pusculary ones, and vice versa. We wrongly give limits to the division
and subtilty as well as to the richness and beauty of nature when we
posit atoms and the vacuum, when we imagine certain primary ele
ments, such as the Cartesians, instead of veritable unities, and when
we do not recognize the infinite in everything, and the exact expres
sion of the greatest in the smallest, united to the tendency of each
to develop itself in a perfect order, which is the most admirable and
the most beautiful result of the sovereign principle, whose wisdom
would leave nothing better to be desired by those who could under
stand its economy.
IX
FRAGMENT OF A LETTEPv TO AN UNKNOWN
PERSON
October l(i, 1707 :
[From the French]
I think, then, I have good reasons for believing that all the differ
ent classes of beings whose union forms the universe, exist in the
ideas of God only as so many ordinates of the same curve, the union
of which does not allow the placing of others between them, because
that would indicate disorder and imperfection. Men are connected
1 Guhrauer, Leibnitz, Elne Biographic, Anmerkungen z. zw. Buche, pp.
31-33. Guhrauer says in the note which contains the Fragment here translated :
"The Principle of Continuity, with which Leibnitz accomplishes so much in
APPENDIX 713
with the animals, these with the plants, and these again with the
fossils, which will be united in their turn with bodies which the
senses and the imagination represent to us as perfectly dead and
shapeless. Now since the law of continuity demands that when ihe
essential determinations of a being approach those of another so that like
wise accordingly all the properties of the first must gradually approach
those of the last, it is necessary that all the orders of natural beings
form only one chain, in which the different classes, like so many
links, connect so closely the one to the other, that it is impossible
for the senses and the imagination to fix the precise point where any
one begins or ends : all the species which border on or which occupy,
so to speak, the regions of inflection and retrogression being obliged
to be equivocal and endowed with characters w:hich can refer to the
neighboring species equally. Thus the existence of Zoophytes for
example, or, as Buddeus l calls them, Plant- Animals, is nowise mon
strous, but it is indeed agreeable to the order of Nature that there
are some. And such is the force of the principle of continuity with
me that, not only should I not be astonished to learn that beings had
been found which as regards many properties, for example, those of
maintaining and multiplying themselves, might pass for vegetables
with as good right as for animals, and which would reverse the ordi
nary rules, based upon the supposition of a perfect and absolute sepa
ration of the different orders of simultaneous beings which fill the
universe ; I should be so little astonished, I say, that I am indeed
convinced that there must be such, that Natural History will perhaps
some day succeed in knowing them, when it shall have studied more
this infinite number of living beings, whose minuteness hides them
from ordinary observation and which are found concealed in the
Psychology, led him to surprising glimpses in his views of animate nature.
Xowhere has Leibnitz expressed himself so clearly upon this subject, as in the
letter to an unknown person, of Oct. 16, 1707, of which a fragment occasioned
the notorious controversy between Maupertuis and Ko'nig, 1752. It stands
with many others in Konig's Appel au Public du jugement de I' academic
roy ale de Berlin, etc. See p. 45. .[Then follows the letter] . . . . This is the
same letter which the Berlin Academy, under the inspiration of Maupertuis,
declared a forgery, and struck off the list of the Academicians Professor
Konig as an impostor. — There are perhaps few pieces of Leibnitz, whose
genuineness are so certified to the connoisseur, as this letter (which Dutens
and Erdmann have overlooked) . Voltaire also (in his letter to Konig) recog
nized its genuineness at once, although only from motives which he drew from
the style. The Academy was right only in the fact that the letter could not
have been addressed to Hermann. Of. Leibn. opp. [ed. Dutens] , 3, 531." — TH.
1 Leibnitz probably refers to Johann Franz Buddeus, 16<>7-1729, assistant
in the philosophical faculty at Wittenberg, Professor of Greek and Latin at
Coburg Gymnasium, of Philosophy at Halle, and of Theology at Jena. He
published Elenienta philosophise practice instrumentalis et theoretics?, Hahe,
1703. — TR.
714 LEIBNITZ'S CRITIQUE OF LOCKE
bowels of the earth and the depths of the waters. We remarked
only since yesterday what grounds have we for denying to reason
what we have not yet had occasion to see? The principle of con
tinuity is then beyond doubt with me, and might aid in establishing
many important truths in the true philosophy, which, raising itself
above the senses and the imagination, seeks the origin of phenomena
in the regions of the intellect. I natter myself that I have some ideas
concerning them, but this age is not qualified to receive them.
THAT THE MOST PERFECT BEING EXISTS1
[From the Latin]
I call every simple quality which is positive and absolute, or
expresses whatever it expresses without any limits, a, perfection.
But a quality of this sort, because it is simple, is therefore irresolv
able or indefinable, for otherwise, either it will not be a simple
quality but an aggregate of many, or, if it is one, it will be circum
scribed by limits and so be known through negations of further
progress 2 contrary to the hypothesis, for a purely positive quality was
assumed.
From these considerations it is not difficult to show that all perfec
tions are compatible with each other or can exist in the same subject.
For let the proposition be of this kind:
A and B are incompatible
(for understanding by A and B two simple forms of this kind or
perfections, and it is the same if more are assumed like them 3), it is
evident that it cannot be demonstrated without the resolution of
the terms A and 7J, of each or both ; for otherwise their nature
would not enter into the ratiocination and the incompatibility could
be demonstrated as well from any others as from themselves. But
now (by hypothesis) they are irresolvable. Therefore this proposi
tion cannot be demonstrated from these forms.
But it might certainly be demonstrated by these if it were true,
because 4 it is not true per $e, for all propositions necessarily true arc
1 Gerhardt, Leibniz, philo.?. Schrift., 7, 2G1-2G2. Cf. Gerhardt's Einleitunf/,
ibid., 251. — TR.
2 Leibnitz had first written : " atque ita ope negationum," i.e. arid thus also
by means of negations. — Gerhardt. — TR.
3 The words, " idemque e\st . . .," were added later. — Gerhardt. — TR.
4 For the following, up to the words: " aut per se notae," Leibnitz at first
wrote: "(esset enim necessaria, neque tamen per se nota)" i.e. for it would
be necessary, and yet not known per se. — Gerhardt. — TR.
APPENDIX 715
either demonstrable or known per se. Therefore, this proposition is
not necessarily true. Or1 if it is not necessary that A and B exist in
the same subject, they cannot therefore exist in the same subject, and
since the reasoning is the same as regards any other assumed qualities
of this kind, therefore all perfections are compatible.
Tt is granted, therefore, that either a subject of all perfections or
the most perfect being can be known.
Whence it is evident that it also exists, since existence is contained
in the number of the perfections.'2
Gerhardt says: "In the foregoing is found what Leibnitz brought
before Spinoza. The following he appears later to have added : "
[The same can be shown also as regards the forms composed from
the absolute forms, provided they are granted.]
I showed this reasoning to D. Spinoza when I was in The Hague,3
who thought it solid; for when at first he opposed it, I put it in writ
ing and read this paper before him.
SCHOL.
The reasoning of Descartes concerning the existence of the most
perfect being assumed that the most perfect being can be known, or
is possible. For this being assumed because a notion of this kind is
granted, it immediately follows that that being exists, since we framed
the notion in such a way that it immediately contains existence. But
the question is asked whether it is within our power to conceive such
a being, or whether such a notion exists on the side of the thing, and
can be clearly and distinctly known without contradiction. For the
opponents will say that such a notion of the most perfect being or of
a being existing through his essence is a chimera. Nor is it sufficient
for Descartes to appeal to experience and to allege that he perceives
the same in such a manner in himself clearly and distinctly, for this
is to break off, not to complete the demonstration, unless he shows
the method through which others also can attain the same experience;
for as often as we bring experiences into the midst of the demonstra
tion, we ought to show others also the method of producing the same
experience, unless we wish to convince them by our authority alone.
? This sentence up to "omnes perfectiones," was added later. — Gerhardt.
-TR.
- At first : " inter perfectiones." — GerharJt. — TR.
8 November, 1676 ; cf. Gnhrauer, Leibnitz, Eine Biographic, Pt. I., 184. — TR.
716 LEIBNITZ'S CRITIQUE OF LOCKE
XI
WHAT IS IDEA1
{From the Latin]
First of all (however), by the term Idea we mean something which
is in our. mind ; marks (vestigia) therefore impressed upon the brain
are not ideas, for I assume as certain that the mind is something else
than the brain, or a more subtile part of the brain substance.
But there are many things in our mind — for example, thoughts,
perceptions, affections — which we know well are not ideas, although
without ideas they would not be produced. For idea for us consists
not in a certain act of thought, but in a power (facilitate), and we say
we have an idea of a thing, although we do not think of it, provided
we can on a given occasion think of it.
There is nevertheless also in this a certain difficulty, for we have a
remote power of thinking about all things, even of those of which we
have not perchance ideas, because we have the power of recovering
them ; idea, therefore, demands a certain power near at hand of thinking
about a thing or facility.
But not even this suffices, for he who has a method which if lie
follows he can attain the thing, does not, therefore, have an idea of it.
As, if I should enumerate in order the sections of a cone, it1 is certain
that I would come into the knowledge of opposite hyperbolas, although
1 have not yet an idea of them. There must necessarily, therefore,
be something in me, which not only leads to the thing, but also expresses it.
That is said to express anything in which are contained conditions
corresponding to the conditions of the thing to be expressed. But
these expressions are varied; for example, the model of the machine
expresses the machine itself, a perspective drawing of a thing in a
plane expresses a solid, an oration expresses thoughts and truths,
letters express numbers, an algebraic equation expresses a circle or
other figure; and because these expressions have something common,
from the contemplation of the conditions of the expressing thing, we
can come into the knowledge of the corresponding properties of the
thing to be expressed. Whence it is evident that it is not necessary
that that which expresses be similar to the thing expressed, provided
a certain analogy of conditions is preserved.
It is also evident that some expressions have a basis in nature, but
others at least are partly based in will (arbitrio), as are the expressions
which are produced by sounds or characters. Those things which
1 Gerhardt, Leibniz, philos. Schrift., 7, 2t>3-264. Cf. Gerhardt's Einleituny,
Ibid., 251-252. — TR.
APPENDIX 717
are based upon nature demand either some similitude, such as exists
between a great circle and a little one, or between a region and a map
of the region ; or at least a connection such as exists between a circle
and an ellipse which represents it in perspective (opft'cc), for any point
whatever of an ellipse corresponds, according to a certain fixed law>
to some point of a circle. Xay, rather, the circle, by any other similar
figure in such a case, would be badly represented. In like manner,
every complete effect represents a complete cause ; for I can always
from the knowledge of such effect, come to the knowledge of its cause.
Thus the deeds of each one represent his mind, and the world itself
in a measure represents God. It can also happen that those things
which arise from the same cause express themselves by turns; for
example, gesture and discourse. So certain deaf persons understand
those who speak, not by the sound, but by the motion of the mouth.
And so the idea of things existing in us is nothing else than the
fact that God, the author alike of things and the mind, has impressed
this power of thought upon the mind, so that out of its own workings
it can draw those things which perfectly correspond to those which
follow from things. And so, although the idea of a circle is not like
the circle, yet from it truths can be drawn which in the true circle
experience would no doubt confirm.
XII
ON THE METHOD OF DISTINGUISHING REAL
FROM IMAGINARY PHENOMENA1
[From the Latin']
Being is that the concept of which involves something positive, or
that which can by us be conceived, provided that which we conceive
is possible, and does not involve a contradiction, which we know,
both if the concept is perfectly explained, and involves no confusion ;
and briefly, if the thing actually exists, for that which exists is cer
tainly a being or a possible thing.
But as far as Being is explained by a distinct concept, so is Existence
by a distinct perception ; and that we may the better understand this,
we must see in what ways existence is proved. And in the first place,
without proof, I affirm existence, from the simple perception or ex
perience of which I am conscious within myself; that is, in the first
place, myself, thinking the various things, then the various phenomena
1 Gerhardt, Leibniz, philos. Schrift., 7, 319-322: Erdmann, Leibnit. opera
philo*., 443-445. — TR.
718 LEIBNITZ'S CRITIQUE OF LOCKE
themselves, or the appearances which exist in ray mind. For these
two, since they are immediately perceived by the mind with the inter
vention of no other, can be wholly proved, and it is equally certain
that there exists in my mind the species of a mountain of gold or of a
centaur, when I dream of these, as it is certain that I exist who dream ;
for each is contained in this one thing, that it is certain that the
centaur appears to me.
Let us now see by what signs we may know what phenomena are real.
We determine this now, both from the phenomenon itself, and from
the antecedent and consequent phenomena. From the phenomenon
itself, whether it be vivid, multiplex, congruous. It will be vivid, if
the qualities, as light, color, heat, appear sufficiently intense : it will
be multiplex if they are varied, and adapted to many tests and to the
institution of new observations; for example, if we experience in the
phenomenon not only colors but also sounds, odors, flavors, tactile
qualities, and those things both in the whole and in its various parts,
which again we can discuss in various relations (variis causis trac-
tare). Which things, indeed, a long series of observations, instituted
especially with design and with choice, is wont to meet neither in
dreams nor in those images which the memory or the phantasy pre
sents, in which the image is very often weak and also disappears
(disparef) in the course of the discussion. The phenomenon will be
congruous when it consists of many phenomena, the reason of which
can be given from themselves in turn, or from some common hypothesis
sufficiently simple ; then it will be congruous if it preserves the usage
of other phenomena which have frequently presented themselves to us
so that the parts of the phenomenon have that position, order, result,
which similar phenomena have had. Otherwise, they will be suspected ;
for if we should see men moved in the air, sitting upon the hippogryphs
of Ariosto, we should doubt, I think, whether we were dreaming or
awake. But this proof can be referred to another head of con
siderations assumed from the preceding phenomena. With which
phenomena the present phenomenon must be congruous, if, namely,
they preserve the same usage, that is, if the reason of this can be
given from the preceding, or all agree with the same hypothesis as a
common reason. But, undoubtedly, the strongest proof is the agree
ment with the whole course of life, especially if very many others
affirm that the same agrees with their own phenomena also ; for, that
other substances similar to us exist, is not only probable, but indeed,
certain, as I shall soon say. But the most powerful proof of the reality
of phenomena, which, indeed, alone suffices, is the success in predicting
future phenomena from the past and present, whether that prediction
is founded in reason, or in the hypothesis thus far succeeding, or in
the usage thus far observed. Nay, although this entire life were saicf
to be nothing but a dream, and the visible world nothing but a
APPENDIX 719
phantasm, I should call this dream or phantasm real enough, if, using
reason well, we were never deceived by it ; but just as we know from
these what phenomena mu'st be regarded as real, so, on the other
hand, whatever phenomena conflict with these which we judge real,
also those whose fallacy we can explain from their own causes, these
only we think apparent.
But it must be confessed that the proofs of real phenomena which
thus far have been brought forward, howsoever united, are not demon
strative; for, although they have the greatest probability, or, as is
commonly said, produce a moral certainty, they, nevertheless, do not
create a metaphysical certainty, so that the assertion of the contrary
implies a contradiction. And thus, by no argument can it be abso
lutely demonstrated that there are bodies, nor anything keep certain
well-ordered dreams from being objects to our mind, which are
considered by us as true, and on account of the agreement among
themselves with respect to use are equivalent to truths. Nor is the
argument of great weight, as they commonly allege, that thus God
would be a deceiver ; certainly, every one sees how far this is from
a demonstration of metaphysical certainty, for we are deceived by o in-
own judgment, not by God, when we assert anything without accu
rate proof. And although there is present great probability, never
theless God is not therefore a deceiver who presents this to us. For
what, if our nature were not perchance capable of real phenomena;
surely God would be not so much to be blamed as to be thanked, for,
by causing these phenomena, since they could not be real, to be at
least accordant, he showed us that which in the entire usage of life
would equal in worth real phenomena ; what, indeed, if this whole
short life were nothing but a certain long dream, and we should awake
only in death ? a conception such as the Platonists seemed to have ;
for since we are destined for eternity, and this whole life, although it
should continue many thousands of years, has in respect of eternity
the value of a point, how small will be the interposition of such a little
dream in the full truth, the ratio of which is much less than that of
the dream to life ; and yet no sane person will say that God is a
deceiver, if by chance he should happen to observe any short but
distinct and congruous dream in his mind.
Hitherto I have spoken of those things which appear ; now we
must see about those which do not appear, which, nevertheless, can
be inferred from those which do appear. And indeed it is certain
that every phenomenon has some cause. Now if any one says that the
cause of the phenomena is in the nature of our mind, in which the
phenomena are, he will affirm nothing indeed false, but nevertheless
he will not express the whole truth. For, in the first place, there is
necessarily a reason why we ourselves exist rather than not exist, and
although we should assume that we existed from eternity, yet the
720 LEIBNITZ'S CRITIQUE OF LOCKE
reason of the eternal existence must be sought, which reason must
be found either in the essence of our mind or outside it,. And,
indeed, there is nothing to prevent the existence of innumerable other
minds as well as ours ; but all possible minds do not exist, which I
prove from this, because all existing things have intercourse with
each other. Further, minds can be known of another nature than
ours and having intercourse with this of ours. Moreover, that all
existing things have intercourse with each other is demonstrated both
from this, that otherwise we cannot say whether anything in respect
to these things happens now or not, and so the truth or falsity of
such a proposition is not given, which is absurd, and because many
extrinsic denominations are given ; nor does any one become a
widower in India by the death of his wife in Europe, without a real
change happening in him. For every predicate is truly contained in
the nature of the subject. If now some possible minds exist, we ask
why not all ; then because it is necessary that all existing things have
intercourse, it is necessary that there be a cause of this intercourse,
nay, it is necessary that all express the same nature, but in a different
way ; but the Cause through which it happens, that all minds have
intercourse or express the same thing and so exist, is that which per
fectly expresses the universe, namely God. The same cause has no
cause and is unique. Hence it is at once evident that many minds
exist besides ours, and since it is easy to think that men who are con
versant with us can have just as much reason to doubt concerning us
as we concerning them, and no greater reason wages war in our
behalf, they also exist and will have minds. Hence already, sacred
and profane history, and whatever things pertain to the state of minds
or rational substances, are considered as confirmed.
With respect to bodies, I can demonstrate that not only light, heat,
color, and similar qualities are apparent, but also motion and figure
and extension. And if anything is real, that alone is the power of
acting and enduring, and so in this (as it were matter and form),
consists the substance of the body ; but those bodies which have no
substantial form, those only are phenomena, or at least aggregates of
the true.
Substances have metaphysical matter or passive power as far as
they express anything confusedly, active, as far as they express it
distinctly.
ADDITIONS AND CORRECTIONS
The following Additions and Corrections are made in the interest of the
greater accuracy and completeness of the book. The material incorporated
therein has been obtained chiefly since the earlier portion of the book was in
type. As it could not be introduced in its proper place, it is deemed best to
insert it here rather than to omit it altogether. It will be noticed that it per
tains chiefly to the earlier portion of the New Essays, the annotation of
which, not a part of the Translator's plan at the outset, began with the print
ing and has grown with the progress of the work. — TR.
PAGE 3, note 2, add : Erdmann, 677-678. The letter, after speaking
of the nature, processes, and extent of our knowledge of physics, proceeds
thus : ;t You enquire concerning the things of spirits or rather concern
ing incorporeal things ; and you say that we see the mechanical disposi
tion of the parts, but that we do not see the principles of the mechanism.
Very well, but when we see motion also, then we know the cause of the
motion or force. The source of the mechanism is primitive force (vis
primitiva*), but the laws of motion, according to which impulses (impetus)
or derivative forces arise out of this primitive force, proceed from the
perception of good and evil, or from that which is most fitting. Thus
it happens that efficient causes depend upon final causes, and spiritual
things are by nature prior to material things, as indeed to us they are
prior in knowledge, because we perceive more immediately (interim) the
mind (nearest — intimam — to us) than the body, as indeed Plato and
Descartes have observed. This force, you say, is known by its effects,
not as it is in itself. 1 reply that so it would be if we had no mind, and
did not know. The mind has in itself perceptions and appetites, and in
these its nature consists. And as in the body we know avriTv-rriav, and
form in general, although we do not know what the forms of the insensible
bodies are, so in the mind we know perception and appetite, although we
do not know distinctly the insensible ingredients of the confused percep
tions, by which the insensible things of bodies are expressed. Spiritual
things are perceived, you say, just as the air, the wind, the light, yet not
on that account sufficiently known ; but to me the air, the wind, the light
seem to be no more spiritual than running water, nor do they differ from
this save in subtility. Spirits, minds, and simple substances or monads in
the universe cannot be comprehended by the senses and the imagination,
because lacking in parts. Do you ask whether I believe that there are
bodies which do not fall within the range of vision ? Why may I not
3 A 721
LEIBNITZ'S CRITIQUE OF LOCKE
believe ? nay, rather, concerning them I think I cannot doubt. In micro
scopes we see animalcula otherwise imperceptible, and the nerves of these
animalcula and other animalcula by chance swimming in their own fluids
cannot be seen. The subtility of nature proceeds into infinity. Finally
you seek for definitions of matter, body, spirit. Matter is that which con
sists in antitypia, or that which resists penetration, and so naked matter
is merely passive. Body, moreover, has besides matter also active force.
Body, moreover, is either a corporeal substance or a mass collected from
corporeal substances. Corporeal substance I call that which consists in a
simple substance or monad (i.e. in the mind or somewhat analogous to
the mind) and in an organic body united to it. But mass is an aggregate
of corporeal substances, as a cheese sometimes consists of a conflux of
worms. Then a monad or a substance simple in kind contains perception
and appetite, and is either primitive or God, in which is the ultimate
reason of things, or derivative, that is a created monad, and this is either
endowed with reason, Mind (metis), or endowed with sense, that is
Soul (anima), or endowed with a certain lower grade of perception
and appetite, or analogous with soul (animce, analoga}, which is content
with the naked name of monad, since we do not know its various grades.
Every monad, furthermore, is inextinguishable ; for simple substances
can neither begin nor end, except by creation or annihilation, that is,
miraculously. And, moreover, every created monad is endowed with a
certain organic body, by means of which it perceives and appetizes,
although it is variously (e)volved through births and deaths, involved,
transformed, and exists in a perpetual flux. Monads, then, contain in
themselves the Entelechy, or the primitive force (vis primitiva}, and
without them matter would be passive merely ; and any mass whatever
contains innumerable monads, for although each organic body of nature
has its own corresponding monads, yet it contains in the parts other
monads endowed in like manner with their own organic bodies serving
the primary body ; and all nature is nothing else, for all aggregates must
necessarily result from simple substances, as it were from true elements.
But atoms or extended bodies, and yet infrangible, are a fiction, which
cannot be explained except by a miracle, and are without reason ; nor
may we from them assign the causes of the forces and motions. And
although they might be admitted, they would not be truly simple, for this
very reason, because they are extended and endowed with parts. Thus I
have replied to your questions, and set forth my views, as far as may be
in a few words and by letter."
PAGE 0, line 15. For " 1709," read " 1704," and cf. infra, p. 101, note
1, line 3 from bottom, and infra, p. 531, note 2, H~H 2, 3, where this por
tion of note 1, p. 101, is corrected.
PAGE 13, note 1. Add: translation also in Duncan, Philos. Wks. of
Leibnitz, 94-99 ; German translation in J. H. v. Kirchmann, Die klein.
philos. wichtig. Schrift. v. Leibniz, 86-92 (Philos. Bibliothek, Bd. 81;
Erlauterungen, Bd. 82), Leipzig, 1879.
ADDITIONS AND CORRECTIONS. 723
PAGE 15, note 2. After "translation," instead of ''Appendix," etc.,
read " Duncan, Philos. \Vks. of Leibnitz, pp. 71-80 ; German translation
in J. H. v. Kirchmann, Die klein. philos. wichtig. Schrift. v. Leibniz,
55-67."
PAGE 16, line 22, " Huygens." Of. infra, p. 150, note 3. On Huygens'
physical views, cf. Lasswitz, Gesch. d. Atomistik, 2, 341-397. New ed.
Huygens, CEuvres completes, La Haye, 1888-1893, 5 vols., still in prog
ress. These 5 volumes contain correspondence only.
PAGE 16, line 30, "pliable." "Leibnitz means," says J. H. v. Kirch
mann, Erlauterungen zu Leibniz, d. klein. philos. wichtig. Schrift., Leipzig,
1879, p. 109, " that, although bodies contain no vacuum, yet from the fact
that they can become greater or lesser in extent, the other substances
which fill out the gaps of the body proper are by pressure removed from
it, or conversely with the cessation of the pressure penetrate into its
vacuum. An actual extension or cohesion of a definite homogeneous body,
which contains no gaps, Leibnitz does not assume, although the Scholastics
affirmed it for a long time." On the development of Leibnitz's views
from the atomism to which he was at first inclined, but almost immedi
ately rejected, to the dynamic idealism of his monad doctrine, cf. D.
Selver, Der Entwicklungsgang d. Leibniz. Monadenlehre bis 1695, Leip
zig, William Englemann, 1885 ; Lasswitz, Gesch. d. Atomistik, 2, 446 sq.
PAGE 17, line 11, " De Seriebus infinitis." Cf. infra, p. 424, note 2.
PAGE 21, line 12, " Fabritius." Cf. infra, p. 102, note 2. The letter
of Fabritius to Spinoza here mentioned is found in Spinoza, Opera, ed.
Van Vloten and Land, 2, 181-182 ; Philos. Wks. Elwes' translation, 2,
374.
PAGE 26, line 4, " Clerc." Jean Le Clerc, 1657-1736, Professor of
Philosophy, Belles-Lettres, and Hebrew in the Remonstrant Seminary at
Amsterdam, 1684-1712, and thereafter of Church History, exercised con
siderable influence in the direction of scientific Biblical criticism, and
wrote several philosophical works ; but his greatest literary influence was
exercised through the serials or reviews of which he was the editor,
among which were the " Bibliotheque universelle et historique," here
mentioned; the "Bibliotheque choisie," Amsterdam, 1703-1713; and the
" Bibliotheque ancienne et moderne," 1714-1726.
PAGE 28, line 6, "Understanding." Cf., also, infra, p. 41. The term
is used in the sense of the Greek vous, Latin ititellectus, to indicate the
totality of the human intellectual powers, the Reason in the larger sense
of that term, in the language of Kant and his school, Vernunft.
PAGE 42, line 10, "Plato." Schaarschmidt says: "This comparison
is to be considered as provisional only, in order to illustrate the opposition
between the author's and Locke's point of view by a familiar example.
Strictly taken the parallel does not hold good, as may be seen from the
724 LEIBNITZ'S CRITIQUE OF LOCKE
addition Leibnitz makes. Aristotle, that is to say, — to call to mind only
the chief antitheses of the respective theories of knowledge, — assumes
before all things principles which are peculiar to the spirit as such, while
Locke denies the same ; Plato, again, recognizes experience by means of
sense-perception in a wholly different, more real, sense than Leibnitz and
affirms in no wise, as Leibnitz, an absolute spontaneity of the presenta-
tive power. ' '
PAGB 42, line 13, " Acroamatic." Cf. infra, p. 272, note 1.
PAGE 42, line 5 from bottom, " Aristotle.1" Schaarschmidt says :
"Aristotle has certainly compared the mind (or the Reason — in his
language vovs), though not the soul in general, with an unwritten tablet."
Cf. Ilepi *vxv, Bk. III., chap. 4, § 11, Berlin Academy ed., 439 b 31 ;
ed. E. Wallace, Cambridge, 1882, p. 159: Set 5' otfrws ciWep ev ypan/j.aTeiv
<i> jj.i]d€v virdpxei- evreXexfig. yeypa^^vov Sirep av^aivfi eirl TOV vov. " This
meanwhile is by no means to be understood in the sense that thought is
merely something taken up from without, the spirit a merely receptive
faculty. According to Aristotle, the thinking spirit is rather partly re
ceptive or passive, partly productive or active, as is clear from this same
Bk. III. of the Ile/ai ^ux^s." Cf., also, Zeller, Philos. d. Griech., 3d ed.,
II.. 2 [Vol. 4], 566 sq.
PAGE 43, line 1, "Schoolmen." The Scholastic philosophy, to which
Leibnitz frequently refers in this and other works, "assumed," says
Schaarschmidt, " a three-fold source of knowledge : 1. Experieutia, ex
perience through the senses ; 2. Ratio, the logical faculty of drawing
conclusions ; 3. Intellectus, the faculty of ideas, which is precisely the
understanding (or spirit) of Aristotle, active for itself from within, not
creative out of sense-experience."
PAGE 43, line 4, "Prolepses." The Stoics derived general ideas or
conceptions, — Koivai two LOU or irpoX^ets, communes notiones, — like all
knowledge, from sensuous perception, explaining them by the persistence
and combination of the sense-impressions. They are not to be under
stood, therefore, in the later sense as innate ideas, independent of ex
perience and peculiar to the spirit as such. The Stoic theory was more
like Locke's than like Aristotle's ; and according to Plutarch, Placitti
philosophorum, IV., 11, considered the soul as originally a blank tablet
( tabula rasa ), upon which the outer world made its impressions.
Through Boethius [470—524] the Stoic theory of knowledge became the
source of mediaeval nominalism. On the Stoic doctrine of knowledge,
cf. Zeller, Philos. d. Griech., 3d ed., Leipzig, 1880, III., 1 [Vol. 5], 70-8(5 ;
Benn, Greek Philosophers, 2, 15 ; Windelband-Tufts, Hist, of Philos.,
202 sq.
PAGE 43, line 14, "Necessary truths." "Leibnitz," says Schaar
schmidt, "here hints at his later more closely grounded division of truths
into necessary and factual (contingent). The former are, according to
ADDITIONS AND CORRECTIONS
Leibnitz, the 'eternal truths of reason,' partly logical laws, partly general
notions which belong to the mind as such, and are developed out of itself
in order to come into consciousness. The latter, the factual truths, are
formed by us through abstraction from experience, and therefore real.
To this antithesis, further developed in the second book, Kant joins on
that of the so-called a priori and a posteriori thought, in that he assigned
to the former the character of necessity and universality, to the latter
that of contingency and actuality (particularity)."
PAG E 44, line 13, "Innate." Leibnitz, in here maintaining that expe
rience can never furnish anything absolutely and universally valid, and
is therefore incapable of serving as the foundation of the sciences dealing
with and requiring absolutely universal fundamental truths, such as
Logic, Metaphysics, and Ethics, indicates in the sharpest and clearest
manner his opposition to Locke's theory of knowledge.
As regards the nature of these pure truths of reason and the method by
which they arise in consciousness, Leibnitz assumes and maintains that
they are developed by the mind out of itself, and thus come into conscious
ness. Of this self -development, " this transition from potentiality to
actuality (a potentia ad actum)," sense-experience furnishes the occasion,
but is not the sufficient reason. Leibnitz to this extent, therefore, main
tains against Locke the " Innateness of Ideas." But "he oversteps this
idealistic principle in so far as he assumes an absolute spontaneity of the
understanding, while at the same time that the understanding itself in its
development is plainly shown in reciprocal action with experience, which
forms the expression of real relation to other beings. In Leibnitz's
theory the ' eternal ' and ' necessary ' truths of reason are in substance
the principles of all knowledge, and furnish accordingly not only the
ground-principles of the formal sciences, like Logic and Mathematics, but
also of Metaphysics and Ethics" (Schaarschmidt).
PAGE 44, line 9 from bottom, "The same reasons hold good." Cf.
H. 8. Reimarus, 1694-1708, Allgemeine Betrachtungen iiber die Kimst-
trie.be der Thiere, 1760, 4th ed. 1798, chap. 2, wAo, says Schaarschmidt,
has treated the antithesis between the knowledge of man and brute,
the investigation of which in our times has led to interesting contro,
versies, better than most of the later writers. Leibnitz assumes a specific
difference between the souls of brute and man, and does not at all agree
with Descartes' view that animals are living but soulless automata. On
animal intelligence, cf. Romanes, Animal Intelligence [International Sci
entific Series, Vol. 44, D. Appleton & Co., New York, 1st ed. 1883. 2cl ed.
1880] ; Mental Evolution in Animals, New York, 1884, D. Appleton & Co. ;
VVrn. Wundt, Lectures on Human and Animal Psychology, translated
from the 2d German edition, by J. E. Creighton and E. B. Titchener,
London and New York, 1894, Lectures 23, 24, pp. 340-366. Wundt's
Lectures include some criticism of Romanes, as somewhat wanting in
critical attitude and exhibiting too much sympathetic imagination.
726 LEIBNITZ'S CRITIQUE OF LOCKE
PAGE 45, line 6 from bottom, " Intellectual ideas." Intellectual, i.e. as
opposed to "sensuous" (i.e. belonging to, or arising from, the senses).
Leibnitz means to say, says Schaarschmidt, either we fasten our attention
upon sense-pictures, whose source is sense-perception, or upon intellect
ual, verstandesmassigen (formulated, sprachgeformten), ideas, thought-
pictures, for whose rise those general ideas, which Kant called Kategories
or original notions of the understanding, are requisite ; general ideas
which do not arise from experience through the senses, but must belong
to our understanding as such and therefore be considered as " innate" or
"implanted."
PAGE 46, line 18, " Virtual." I.e. Potential, or, as opposed to " actual,"
the real-possible. " It is here," says Schaarschmidt, "the faculty through
which a substance (the soul) out of its own supreme power goes over into
a new condition as for it a new realization. Our soul contains an unend
ing number of possible ideas, as capacities, seeds or traces left behind and
remains of former activity, which upon definite occasion it realizes, i.e.
calls into consciousness. This Leibnitzian application of the — originally
wider— Aristotelian concept of power to the soul has become for modern
philosophy in the highest degree weighty and fruitful."
PAGE 46, line 7 from bottom, " Reminiscence." On the Platonic doc
trine of " reminiscence " or " recollection" (d«fc/*i^<ris), an essential part
of his doctrine of Ideas, cf. Windelband-Tufts, Hist, of Philos. pp. 118,
119; Zeller, Philos. d. Oriech., 4th ed. 1889, II., 1 [Vol. 3], 823, 824,
835, 836.
In Plato's philosophy the ideas which are the objects of our rational
thought were intuited by the soul in its pre-existent and exalted state
when it dwelt in the presence of the archetypal forms (Trapa.5eiyfj.aT a),
which Plato called ideas (etdij or tftat). The soul in its earthly life is
but dimly, if at all, conscious of these archetypal forms, till the percep
tion of their imperfect copies in corporeal things arouses the slumbering
recollection and stimulates the soul to reproduce them in consciousness
and with the aid of dialectic again to attain the knowledge of true and
ideal reality. Cf., also, New Essays, Book I., chap. 1, § 5, Th. (3), infra,
p. 79
PAGE 47, line 8, "Reflection." "Provided," as Schaarschmidt says,
"that Reflection, which with Locke has to do only with the activities of
the inner nature as such, receives that further content which embraces
the ' eternal ' and ' necessary ' ground-truths, and to which we are in fact
led if we keep in mind the presuppositions and modalities under which
those activities proceed."
PAGE 47, lines 18, 19, " The book of Boyle against absolute rest." Cf.
infra, p. 324, note 2. The treatise is also found in Vol. 1 of the Latin
version of his works, Opera varia, Geneva, 1680, and later, with the title
Dissertatio de intestines motions particularum solidorum quiescentiuni, in
qua absolnta corpornm quits in disquisitionem vocatur. On Boyle, cf.
ADDITIONS AND CORRECTIONS 727
Lasswitz, Gesch. d. Atomistik, 2, 261-293 ; Lange, Gesch. d. Materialis-
mus, 2d ed. Iserlohn, 1873. 1, 255; English translation, Boston, 2d ed.
1879, 1, 299-306.
PAGE 47, line 21, "Doing away with atoms." Leibnitz rejects atoms
in favor of his own monads, because the monads contain in themselves the
principle of motion as active force, while the atoms are assumed in conse
quence of a force in movement foreign to them. On Leibnitz's view and
its development, cf. Lasswitz, Gesch. d. Atomistik, 2, 470 sq.
PAGE 48, line 7 from bottom, "Confused in the parts." Cf. infra,
pp. 120, 317, note 2, 319, 320, 458, 459. Leibnitz's doctrine of "minute
perceptions" or, in the philosophical language of to-day, "unconscious
mental states," is of the greatest significance in psychology and episte-
mology, and never more so than at the present time. For an excellent
exposition of it, cf. Windelband-Tufts, Hist, of Philos., pp. 423 sq., 462 sq.
PAGE 48, last line, " Hippocrates." Cf. infra, p. 476, note 2.
PAGE 49, line 15, "Sufficiently distinguished." That is, to reach con
sciousness. The perceptions are not sufficiently strong to call forth a
conscious activity of the soul.
PAGE 49, line 12 from bottom, "Author of the most excellent of dic
tionaries." The reference is to Bayle. Cf. infra, p. 507, note 1.
PAGE 49, note 1. The note should read: Cf. Vergil, Georg. IV., 393.
Gerhardt's reading : "que" is evidently a typographical error. Erdmann
and Janet read : " quce mox futura," etc.; Jacques, correctly: qim mox
Centura trahantur."
PAGE 50, line 15, " Pneumatology." Cf. infra, p. 362, note 2.
PAGE 50, line 20, " Law of Continuity." Cf. infra, p. 334, note 1 ;
p. 552.
PAGE 50, note 3. Add: The correspondence of Leibnitz and Basnage
is found in Gerhardt, Leibniz, philos. Schrift., 3, 73 sq.
PAGE 51, line 7, " Numero." Cf., also, infra, p. 332, note 1.
PAGE 51, lines 11-13, "Perfect globes of the second element, born of
cubes perfect and original." The reference is to Descartes, Principled
Philosophies, Pt. III., §§ 48 sq. Cf., also, New Essays, infra, p. 552,
note 1. Mahaffy, Descartes, Blackwood's Philosophical Classics, Edin
burgh, 1881, p. 159, says Descartes' theory of general physics was elabo
rated as regards minerals. This fact perhaps accounts for Schaarschmidt's
translation : " des sichtbaren Metalls" and his reference to Prin. Philos.,
Pt. IV., §§ 70, 75, in his note, Erlauterung, 400, p. 101, to the passage,
Xcw Essays, Bk. IV., chap. 16, § 12, Th., p. 532 of his German transla
tion. Descartes, says Mahaffy, ibid., p. 159, gave special explanation
of the growth of the human body, but that of plants and the lower
animals was wanting when he died. On Descartes' theory, cf. Lasswitz,
Gesch. d. Atomistik, 2, 89.
728 LEIBNITZ'S CRITIQUE OF LOCKE
PAGE 51, lines 19, 20, " Present considerations.1' While the process of
abstraction allows us, in order to their better apprehension, to concen
trate our attention for the time on certain properties or attributes of a
subject to the exclusion of others, yet we must remember that in so doing
we are departing from reality and only partially representing it in con
sciousness.
PAGE 51, line 20. Instead of the rendering: "If it were very well
understood," read, after Schaarschmidt, " If we take it as pure and
si mple gospel, ' ' etc.
PAGE 51, line 29, "Some exception." Nature gives us no perfect
circles, perfect spheres, etc. Perfect mathematical regularity of form
exists only in thought.
PAGE 52, line 7 from bottom, "Strong-minded." That is, the "Free
thinkers," as Leibnitz at other times called them, who thought they might
deny immortality itself after the pretended proofs for it given by Scholas
ticism had been disproved.
PAGE 53, line 8 from bottom, " Averroists and some bad Quietists."
Of. infra, p. 581, note 1. The Mystics and Quietists approached very
nearly this Averroistic doctrine of a denial of personal immortality. In
Leibnitz's time the Mystics and Quietists were especially the followers of
Madame Guy on, who was ready "to burst from an overplus of divine
grace," and of Ant. Bourignon, on whom cf. infra, p. 599, note 2 ; also,
according to Schaarschmidt, Leibnitz's letter CXLIV., Feder, Commercii
epistolici Leibnitiani, Hanover, 1805, p. 459.
PAGE 54, note 1. Add: Leibnitz was much interested in the Locke-
Stillingfleet controversy, as his correspondence with Thomas Burnett
shows. Cf. Gerhardt, Leibniz, philos. Schrift., 3, 149-329, passim, and
especially pp. 205, 216, and the two essays, pp. 223-242 ; also Foucher
de Careil, Lettres et opuscules inedits de Leibniz, Paris, 1854, Introduc
tion, pp. Ixii sq., and Leibnitz's Remarques sur le Sentiment de M. de
Worcester et de M. Locke, ibid., pp. 1-26. The latter piece is identical
with that published — not therefore for the first time — by Gerhardt, op.
cit., 3, 229-242. The controversy, like that of Leibnitz and Arnauld,
served to bring Locke to the further explication and limitation of his
views.
PAGE 55, lines 16, 17, " French version." That is, by Pierre Coste,
with the co-operation of Locke. It appeared in 1700, then in 1729, and
again in 1742. Cf. ante, p. 4, note 1. For the correspondence of Leib
nitz and Coste, cf. Gerhardt, Leibniz, philos. Schrift., 3, 377-436. Before
Locke published, in 1690, his Essay, he published an abstract, translated
into French by Le Clerc in Le Clerc's " Bibliotheque universelle," Janu
ary, 1688. Cf. ante, p. 4, note 1, and Fraser's Lockers Essay, 1, 15.
note 2. The abstract or " Epitome " is found in Lord King's Life and
Correspondence of Locke, new ed., London. 1830, 2, 231-293 ; Bohn'sed..
1858, 1 vol., pp. 365-399.
ADDITIONS AND CORRECTIONS 720
PAGE 55, last line, " Intentional' species." Cf. infra, p. 381, note 1.
TAG*: 56, line 3. For the Latin verse, rf. Ovid, Tristia, I., 8, 7.
PAGE 59, line 4 from bottom, " Inexplicable qualities." That is, the
qnaJitates occultce of the mediaeval philosophers.
PAGE t>0, line 6 from bottom, " Instructive." Leibnitz, as Schaar-
schmidt says, "avails himself of Stillingfleet's polemic against Locke,
which is of particular interest because it shows Locke's uncertainty in
regard to the weighty question of the substantiality of the soul, to add
thereto the statement that the soul must be immaterial. Locke himself,
so he argues, has admitted that thought is not conceivable as a modifica
tion of matter, or that, in other words, a thinking being cannot be a mere
mechanism ; thus the soul is to be considered as something immaterial,
since the thought, that God may through a miracle have bestowed, thought
upon matter, is an impermissible subterfuge." For further discussion of
the point, cf. New Essays, Bk. IV.
PAGE 62, line 10 from bottom, " Miracle pure and simple." Cf. infra,
p. 428. The doctrine of a purifying fire through which souls have to pass
after death goes back to the early period of the church, but became more
prominent and was more generally adopted from the time of Gregory the
Great (c. 540-604). Cf. Hagenbach, Hist, of Doctrines, ed. H. B. Smith,
8 141, Vol. 1, p. 373 ; § 206, Vol. 2, p. 126. Clement of Alexandria, Stro-
niateis, vii. , 6, says: (fra.iJ.tv 8' ^/uets dyid^eiv TO irvp, ov TO. Kpta, d\\a ras
a fj-apr ajXous i/'i/xds ' TVP ov rb irdfj.(payov /cai fiavavcrov, dXXa TO cpp6viij.ov
XtyovTfs, TO duKvov/jLevov did i/^X^s Trjs dtepxofj-evris TO irvp, i.e. '• We say that
fire sanctifies not flesh, but sinful souls, speaking of that fire which is
not all-devouring, such as is used by artisans, but of that which is dis
criminative, pervading the soul which passes through the fire " (the phrase
••discriminative" (<pp6vifwv') , or as Bigg, The Christian Plato nists of
Alexandria [Bampton Lectures for 1886], p. 113, translates it, " wise fire,"
•'comes," says Bigg, "from Heraclitus and the Stoics.") Cf. Bigg, op.
cit., 295; Hagenbach, op. cit., § 77, 1, 222. And Augustine, De Civit.
Dei, Bk. XXL, chap. 10, Benedictine ed., Paris, 1685, Vol. 7, p. 631,
says: '^Gtlflmim non dicamus, quamvis miris, tamen veris modis etiam
spiritus incorporeos posse pcena corporalis ignis affligi, si spiritus hoini-
num, etiam ipsi profecto incorporei, et nunc potuerunt includi corporali-
bus membris, et tune poterunt corporum suorum vinculis insolubiliter
alligari ? " i.e. " For why may we not assert that even immaterial spirits
may, in some extraordinary way, yet really be pained by the punishment
of material fire, if the spirits of men, which also are certainly immaterial,
are both now contained in material members of the body, and in the
world to come shall be indissolubly united to their own bodies ? " ( The
City of God, 2, 435, translated by Rev. Marcus Dods, M.A., T. & T. Clark,
Edinburgh, 1871). In chapter 7, after having in previous chapters cited
many real or supposed facts from the natural world in support of the pos
sibility at least of the view, he admits that it is miraculous and beyond our
730 LEIBNITZ'S CRITIQUE OF LOCKE
knowledge, and maintains the omnipotence of God as the ultimate reason
for belief in miracles. Thos. Aquinas, Summa Theol., Qusest. 70, Art. 3,
Concl.,says: " Respondeo : Dicendum quod ignis inferni [i.e. purgato
rial fire, according to the context] non sit metaphorice dictus, nee ignis
imaginarius, sed verus ignis corporeus," etc. Only those requiring purga
tory go there, according to St. Thomas, cf. Quaest. 69, Art. 2. Bellamin,
1542-1621, in his De Purgatorio, chaps. 10-12, investigates the method
of the purgatorial fire and follows Augustine in teaching that it is mate
rial and miraculous in its action upon the soul.
PAGE 63, line 10 from bottom, "Demons or goblins." "Leibnitz is
perhaps here thinking," says Schaarschmidt, "of the so-called Spirits of
the Elements (Elementargeister), of which the 'philosophers and physi
cians of the past,' especially Theoph. Paracelsus [c/. infra, p. 645, note 1],
had treated, both in his Philosophia sagax, and in a special book, DC
nymphis, sylphis, pygmasis et salamandris, or even of the ' spiritus famili-
«m.' of others, as of the Italian philosopher and physician Hieronymus
Cardanus [cf. infra, p. 566, note 1], who in his interesting autobiography
[De vita proprict], chap. 47, discusses the subject and at the same time
narrates marvellous experiences of his own past life."
PAGE 63, note 3. Add : In the Philos. Mosaica, and also in his
Utriusque Cosmi — Metaphysica, physica atque technica Historia, Oppen-
heimii, 1617 fol., "God appears," says Schaarschmidt, "as the ani
mating and moving principle of things, in that all power streams forth
in a miraculous way from him into matter, in order afterwards to turn
back again from the thereby occurring differentiation to unity." On
Fludd, cf. Lasswitz, Gesch. d. Atomistik, 1, 329 ; Stockl, Gesch. d. Philos.
d. Mitteialters, III. [Vol. 4], 472-476.
PAGE 64, note 1. Add: Prof. A. C. Eraser, in his edition of Locke's
Essay concerning Human Understanding, Oxford, 1894, follows Coste's
French version in separating the introductory chapter from the First Book,
and making, with Leibnitz here, but three chapters in Bk. I.
PAGE 64, note 2, line 2. After "1674," add: new ed. with notes by
Bouillier, Paris, 1880,2 vols. ; line 4, after " Bernier," add : On Gassendi,
cf. Stockl, Gesch. d. Philos. d. Mitteialters, III. [Vol. 4] 316-327 ; Lange,
Gesch. d. Materialismus, 2d ed., Gerlohn, 1873, 1, 223-234, Eng. trans. 2cl
ed. 1, 253-269 ; Lasswitz, Gesch. d. Atomistik, 2, 126-188. On Bernier's
later divergence from Gassendi, cf. ibid. 2, 504.
PAGE 65, line 13. Instead of " Doctors," read: " scholars."
PAGE 65, note 1. Add: Lady Masham, 1659-1708, was one of Locke's
most intimate and truest friends, kept him by her at her country seat at
Oates and nursed him in his last illness. Cf. Gerhardt, Leibniz, philos.
Schrift. 3, 365. Lady Masham presented Leibnitz with a copy of her
father's Intellectual System, as appears by his letter of March 29, 1704, cf.
Gerhardt, 3, 338.
ADDITIONS AND CORRECTIONS 731
PAGE 65, note 3. Add : The objections referred to in the text are the
objectiones quintal against Descartes' Meditationes de prima philosophia,
" which indeed," as Schaarschmidt says, " contain a series of very acute
objections and gave Descartes much trouble." The Cinquiemes Objec
tions of "Gassendy," with the Reponses of Descartes thereto, are found
in Cousin, CEuvres de Descartes, 2, 89 sq., 241 sq.
PAGE 66, line 6, " Inclined towards ethics." Leibnitz, who to a certain
extent may be considered as giving utterance to his own views in the»
person of Theophilus, here throws out a hint to be well taken to heart as
regards his own course of development. As a natural consequence of his
early studies in jurisprudence, Leibnitz was led to a deeper study of ethical
conceptions, and in like manner his study of Descartes made him
acquainted with the problems of mathematics and physics, which he
thoroughly examined only later after his sojourn in Paris.
PAGE 66, lines 13, 14, "No longer a Cartesian." Cf. the entire context,
pp. 66-69, also Leibnitz's letter to Remond de Montmort, January 10,
1714, Gerhardt, Leibniz, philos. Schrift. 3, 606-607, Erdmann, 701-702, in
which Leibnitz gives a brief account of his own philosophical studies and
development, including, Plato, Aristotle, and the Scholastics and thence
passing to the moderns, rejecting the " substantial forms" for the mechan
ism of the Cartesian system, and then developing his own doctrine of Pre-
established Harmony. The difficulties and controversies within the
Cartesian School and against it led Leibnitz to his own doctrine, and he
remarks in his Considerations sur le Principe de Vie, 1705, Gerhardt, 6,
540, Erdmann, 430, as also in the letter here cited, that if Descartes had
known that Nature conserves not only the same force, but also the same
total direction in the laws of motion, he would himself have come to the
system of pre-established harmony. Cf. W. Sigwart, Die Leibniz'sche
Lehre v. d. prdstabilirten Harmonie. Tubingen, 1822, pp. 110-112, 117,
118, 121, 132, etc. For Leibnitz against Descartes and Cartesianism, cf.
Gerhardt, 4, 265-406 ; also, Stein, Leibniz u. Spinoza, 60 sq.
PAGE 66, line 17, "New System." That is, The System of Pre-
established Harmony, in explanation and defence of which Leibnitz
published in the journals mentioned many essays, most, if not all, of which
are mentioned later in either the text of the New Essays or notes thereto.
"Leibnitz," as Schaarschmidt well says, "can truly boast that he has
turned to account for his own system moments of all the doctrines named
in the text," it being "a characteristic feature of Leibnitz's thought to
ascribe a relative truth to each philosophic system and accordingly to wish
to extract from it a good side in order, by harmonizing these different
elements, to bring to pass the possibly best view of the world." Cf.
Leibnitz's letter to Remond de Montmort, January 10, 1714, Gerhardt,
Leibniz, philos. Schrift. 3, 606, Erdmann, 701 : " Outre que j'ay eu soin
de tout diriger a 1'edification, j'ay tache de deterrer et de re"unir la ve"rite
eusevelie et dissipee sous les opinions des differentes Sectes des Philosophes,
732 LEIBNITZ'S CRITIQUE OF LOCKE
et je crois y avoir adjoute quelque chose du mien pour faire quelques pas
en avant."
PAGE 66, note 1. Add : Geronimo Korario, 1485-1566, an Italian
litterateur, Nuncio of Clement VII. at the Court of Ferdinand, King of
Hungary, maintained, against the Cartesians and the followers of Aristotle,
that the beasts have reason and make better use of it than man. His book,
Quod animalia bruta scepe ratione utantur melius homine, appeared first
in 1648, then 1654 at Amsterdam.
PAGE 6,7, lines 3, 4, "Life and perception in all things." The doctrine
of the universal soulhood (Allbeseeltheit) goes back to the world-soul of
Plato, as developed especially by Plotinus (cf. \Vindelband-Tufts, Hist, of
Philos., 245 sq.), and is connected in part therewith, and partly with the
pantheistic tendencies represented, for example, by the Averroists (cf.
Vew Essays, infra, p. 581, note 1). Leibnitz rejects both errors by his
Monadology, which conceives the universal soulhood of substances in an
individual and not in a pantheistic way. In modern times the doctrine
appears in Giordano Bruno, 1548-1600 (cf. Delia Causa, Vol. II., pp. 239-
241, ed. A. Wagner, Leipzig, 1829, new ed. by P. de Lagarde, 2 vols..
Gottingen, 1888, German trans, by Lasson, Berlin, 1872, in J. H. v. Kirch-
mann's Philos. Bibliothek, Vol. 53), and in Jacob Boehme (cf. infra,
p. 298, note 1). On the doctrine as found in Bruno and Boehme, cf.
Windelband- Tufts, op. cit., 367 sq., 373 sq. Spinoza, Ethica, Pt. II.,
Prop. XIII., Scholium, ed. Van Vloten and Land, 1, 86-88 ; Elwes'
trans., 2, 92, also gives expression to the same thought.
PAGE 67, line 5, " Countess of Connaway." Anne — Viscountess Con-
way — died Feb. 23, 1678-9, was a metaphysician and an earnest student
of Plato, Plotinus, Philo Judseus and the " Kabbala Denudata." In spite
of never-ceasing sufferings from a severe headache lasting till her death,
she pursued her metaphysical studies with extraordinary devotion and
assiduity. Her physician, Francis Mercury van Helmont (cf. infra, 242,
note 2), encouraged her in this course. She was very friendly with H.
More and corresponded with him on philosophical and theological topics.
She wrote many works of which only one has been printed : Opuscule
philosophic a qxt'bus continentur principia philosophice antiquissimaz et
recentissimw, Amsterdam, 1690. It was the first in a collection of philo
sophical treatises appearing in Latin in that year at Amsterdam, translated
as "a work by a certain English countess, 'learned beyond her sex,1 ''
and ascribed by Leibnitz in a German literary journal, on the authority of
Van Helmont. to the Countess of Conway. The treatise was re-trans
lated into English and published with the title The Principles of the Most
Ancient and Modern Philosophy, etc., London, 1692, 8vo.
PAGE 67, note 1. Add: On Campanella, cf. Stockl, Gesch. d. Philos. d.
Mittelalters, III. [Vol.4.], 343-366 ; Lasswitz, Gesch. d. Atomistik, 1, 340-
342.
PAGE 67, note 2. Add : On Van Helmont, cf. infra, p. 242, note 2 ; on
H. More, cf. infra, pp. 380. note 1 ; 382, note 2, and addition thereto,
infra p. 768.
ADDITIONS AND CORRECTIONS 783
PAGE 67, note 3. Add: Further references to Archseus in Leibnitz's
writings are: Specimen Dynamlcum, Gerhardt, Leibniz, math. Schrift.,
II.. 2 [Vol. 6], 242, also infra, Appendix, p. 679 ; Hypothesis phys. nova,
Theoria motus concreti, § 60, Gerhardt, Leibniz, philos. Schrift. 4, 217;
math. Schrift., IT., 2 [Vol. 6], 57; Dutens, Leibnit. op. om., 2, Ft. II.,
33 ; Leibnit. Animadversiones circa Assertiones aliquas Theories Medicce
uerce Clar. Stahlii, Dutens, op. cit., 2, Pt. IT., 130. Cf.. also, Windel-
band-Tufts, Hist, of Philos. 371 sq.
PAGE 68, line 10, " Morte carent aninw." Cf. Ovid, Metamorphoses,
15, 158.
PAGE 68, line 20, ••Spontaneity.'" Leibnitz ascribes absolute spon
taneity to the soul, to which the activity of the body perfectly corresponds
through the Pre-established Harmony, and therefore neither influences
nor disturbs it.
PAGE 68, line 7 from bottom, "Epitome." That is in the Monad, each
monad representing in itself and to itself the entire universe. Leibnitz
constantly recurs to this thought, which is one of the chief points of his
system. Cf. Systeme nonveau de la nature. § 16 ; Monadologie, § 65, etc.
PAGE 69, note 1. Add : also G. Groom Robertson, Philos. Y?f •»?///».<?,
Williams & Xorgate, 1894, pp. 334-342.
PAGE 70. line 5 from bottom, " Copernicans." Kant, later in the
Preface to the 2d ed. of his Kritik d. reinen Vermin ft, makes use of the
same comparison of Copernicus.
PACK 71. line 24, '• Confused perceptions." Cf. ante, p. 48 and note to
line 7 from bottom, ante, p. 727. " While Leibnitz," says Schaarschmidt,
'• often returns to this antithesis of truths of reason and of fact, he has
unfortunately nowhere given accurate definitions of the former, nor any
wholly satisfactory criterion of a truth of reason. Kant first undertook
this task, in that he certainly on the one side significantly restricted the
service of the truths of reason, on the other, that against Leibnitz he
recognized that for the reason as such complete (fertige) concepts are to
arise out of the truths of reason."
, PAGE 72, note 1. Add : " The Later Arminians," says Schaarschmidt,
•• are here referred to, as the leaders of this religious sect, such as Episco-
pius, Lirnborch, J. Clericus, like Descartes and Leibnitz himself, assume
a knowledge of God derived from natural reason."
PAGE 74, line 8 from bottom, "Natural light." Cf. infra, pp. 575-576,
note 1.
PAGE 74, lines 4. 3, from bottom, " Verification." Cf. ante, p. 71, note
to line 24, above, and also New Essays, Bk. IV., chaps. 9, 11. Leibnitz
here presents as the criterion or test of innate ideas their immediacy in
consciousness. Spinoza before him (Ethica, Pt. II., Prop. 43, Scholium,
ad fin., ed. Van Vloten and Land, 1, 111 ; Elwes' trans., 2, 115 ; cf., also,
F. Pollock. Spinoza, hi* Life and Philosophy, 129 sq.), said : " Sane sicut
734 LEIBNITZ'S CRITIQUE OF LOCKE
lux seipsam et tenebras manifestat, sic veritas norma sui et falsi est."
Cf., also, Descartes, Prin. Philos., Bk. I., § 45 ; ed. Cousin, 3, 90; Veitch's
trans., 212, where he sets forth the doctrine of "clear and distinct"
knowledge and of intuition through which we become immediately con
scious of the truth as such. Cf., also, Descartes, Regular ad directionem
ingenii (Regies pour la direction de V esprit), Opuscula posthuma Cartesii,
Amsterdam, 1701, III., p. 6 ; IV., p. 9; VI., p. 14 ; ed. Cousin, 11, 209,
215, 226.
PAGE 75, note 1. Dele note. The Ludolph here referred to by Leibnitz
is Ludolph van Ceulen, or Keulen, 1539-1610, Professor of Military Archi
tecture in the University of Ley den since 1600, and previously teacher of
mathematics in Breda, Amsterdam, and Leyden. He published his Van
de Circkel, daarin geleert wird te finden de nceste proportie des Circkels-
diameter iegen synen Omloop, Delft, 1596 ; Latin trans, by Snellius, en
titled De circulo et adscriptis, 1615. His De arithmetische en geometrische
fondamenten, etc., Leyden, 1616. Fundamenta arithmetical et gcometrica
and Zetemata (sen Problemata') geometrica, both trans, from the Dutch
by Snellius, Lugd. Bat., 1615. He computed the ratio of the diameter
to the circumference of the circle to 35 places of decimals. The ratio
is commonly known in Germany by the name " Ludolphische Zahl."
Leibnitz refers to him in his mathematical writings, cf. Gerhardt, Leibniz,
math. Schrift. II., 1 [Vol. 5], 95, 119. For Leibnitz's discussions of the
subject, cf. infra, p. 424, note 2.
PAGE 77, line 6 from bottom, " Subvenire.1" Schaarschmidt translates
" Beikommen," and in his note to the passage states that "the French
souvenir (to remember) made from subvenire, originally means : to come
to the aid of. The expression of help introduced by the Heidoartian phi
losophy could, unfortunately, not be used, since the word-play would be
wholly lost."
Leibnitz's thought is that reminiscence, the active and voluntary factor
in the reproduction of the past and in bringing the now unconscious
knowledge again into consciousness, requires and receives the aid of
remembrance or memory, the conservative factor in the process, which in
some unknown and mysterious way, and out of consciousness, preserves
as in a store-house the knowledge previously acquired or possessed. Of.
Hamilton, Metaphys., Lect. 20, pp. 274-275, American ed., Boston, 1875.
PAGE 78, line 16 from bottom. The sentence should read thus : "For
through an admirable arrangement of nature we cannot have abstract
thoughts which do not require something sensuous, although this should
consist only of such characters as are the forms of the letters and the
sounds."
PAGE 79, line 8 from bottom, "Opinion of the Platonists." Cf. ante,
p. 46, and note to line 7 from bottom, ante, p. 726.
PAGE 80, note 1. Add: Janet also reads: "ou." Schaarschmidt
translates " wo," cf. his translation, p. 45, line 13 from bottom. The
ADDITIONS AND CORRECTIONS 735
context seems to require here the reading "ou," where. The reading
" ou " is probably a MS. or typographical error.
PAGE 83, note 1. Add: For an account of his views, cf. Lasswitz,
Gesch. d. Atomistik, 2, 188-207. Digby's doctrine on the subject men
tioned in Leibnitz's text is found in his Demonstratio immortalitatis
animce rationales, Tract. I., cap. 3, p. 26 sq., ed. Francofurti, 1664, full
title of which Lasswitz gives, op. cit., 2, 188, note 3 ; and in his Institu-
tiones peripateticce, published as an Appendix to the Demonstratio, ed.
of 1664. Schaarschmidt gives 1st ed. of Demonstratio, Paris, 1655. A
treatise of the nature of bodies, Paris, 1644.
PAGE 86, line 8, " Sadness is." Says Schaarschmidt : " We are imme
diately conscious of the theoretical ground-truths as such. With the
practical, the case is different. Joy and sorrow we certainly feel immedi
ately as such, but to find out their real nature requires subsequent reflec
tion."
PAGE 87, note 2. After " Erdmann," add : Janet ; and after "Bonn's
edition," add : Eraser's Locke's Essay, 1, 67, line 18.
PAGE 88, line 13 from bottom, "Instinct." "Leibnitz understands
here by instinct," says Schaarschmidt, "a definite inclination to a certain
manner of action, which arises out of need and serves to satisfy the same.
' Truths of instinct ' thus refer themselves back to our nature and are
accordingly, in conformity with Leibnitz's general view, innate truths."
PAGE 89, note 2. Add : A German translation, by G. E. Bottger, ap
peared at Nordhausen, Gross, 1787.
PAGE 89, note 3. Add : According to Schaarschmidt, the story is found
in Bk. II., chap. 1, p. 73, of Baumgarten's, " very interesting but rare,"
Perigrinatis in ^Eyyptum, Arabiam, Palccstinam et Syriam, Noribergae
ex off. Gerlachiana, p. P. Kaufmannum, 1694, 4to.
PAGE 91, line 5, " esse." Cf. Digest or Pandects, Bk. I., Tit. 1, § 3,
where Elorentinus says: " Ut vim atque injuriam propulsemus. Nam
jure hoc evenit, ut quod quisque ob tutelam corporis sui fecerit, jure
fecisse existimetur, et, cum inter nos cognationem quandam natura con-
stituit. consequens est hominem homini insidiari nefas esse." Corpus
Juris Civilis Academicum Parisiense, p. 229, 7th ed., Lutetiae Parisiorum
1862 ; Corpus Juris Civilis (Digesta recog. T. Mommsen, and paged sepa
rately), Berlin, Weidmann, 1893, Vol. 1, p. 1.
PAGE 91, line 8 from bottom, " Complete certitude to morals." Schaar
schmidt here compares Hume, "the most acute (scharfsinnigste} of the
English philosophers," who "reached a similar result, wholly indepen
dent of Leibnitz," in his An Inquiry concerning the Principles of Morals,
Section I., cf. The Philos. Wks. of David Hume, 4 vols., Little, Brown, &
Co., Boston, 4, 233 : " The final sentence, it is probable, which pronounces
characters and actions amiable or odious, praiseworthy or blamable ;
730 LEIBNIT/S CRITIQUE OF LOCKE
that which stamps on them the mark of honor or infamy, approbation or
censure ; that which renders morality an active principle, and constitutes
virtue our happiness, and vice our misery; it is probable, I say, that this
final sentence depends on some internal sense or feeling, which nature has
made universal in the whole species. . . . But in order to pave the way.
for such a, sentiment, and give a proper discernment of its object, it is
often necessary. \ve find, that much reasoning should precede, that nice
distinctions be made, just conclusions drawn, distant comparisons formed,
complicated relations examined, and general facts fixed and ascertained.'1
Cf. , also, Hume. .1 'J'rcntise of Human Nature, Bk. III. Of Morals,
1't. I., Sect. II.. ed. (iiven and Grose, 2, '241.
P\<;i: 01. line 3 from bottom. •• Boutan." That is. Bhutan, a district
in the Eastern Himalayas, north of Assam.
Pvc.i: 02, line 0. •• Often confused." •• Feeling here means." as Schaar-
schmidt says, •• not the sensuous-psychical sensation, but the confused
complex of presentations (Vor*tellnn<ji>n} — a frequently used significa
tion of the term — which occupies the soul and therefore often drives it to
action. Feelings of this kind may by self-reflection be resolved into more
or less clear and distinct ideas (Vorstellungen), a process necessary for
testing and correctly estimating their content. Leibnitz at this time
appears to regard all feelings without exception as such undeveloped
ideas and judgments.''
PA<;I: 03, line 20. "Joseph Scaliger." Cf. infra, p. 10(5, note 2.
PACK 05. note 1. Add : The five principles here referred to are found
in the De Veritate. and in the De Iteli</i(»>e Laid, annexed to the 3d ed.,
London. 1045, of the De Verit. Cf. Eraser's Lucked Essay. 1, 80. note 2 ;
81, note 1.
PA<;K 00. note 1. After " ad init.S* add : 15. Berlin Academy ed.. 1100b
30: (0-TLv, apa 77 apery e£ts TrpoaipcriKrj ev /iecroTTjTt of/era TT? Trpos i]/J.a$
upifffjitvig \6yw Kai us av 6 (ppovijjios 6picrei.ei> • fMCfforrjs 5e dvo /caA.'icDi', rrjs /u.€i>
K0.6' virfpfioXriv rrjs df KO.T' eXXei^iv . . . 5io Kara fj.ei> TTJV oixriav Kai rbv
\6yov rbv ri ?ji> civai \fyovra fj.f<7orr]s €(rriv 77 aperv;, Kara 5e TO aptcrrov Kai rb
ev aKporTis.
Pv<;i: (.»7. note 1. Add: A long time after this note was in type, I
came across the following in Guhrauer, Leibnitz's Deutsche Schriften, 2,
•")00. among some V?nnixchte Bfincrkunyeu und Urtheile . . . Ann dem
MondtlirJien An#zu<j<". "(October, 1701). Ilei-r Boile.au Despreaitx, ein
franz(")sischer Academicus und beriihmter Satyricus, hat eine neue und
vennehrte Edition seiner Satyren machen lassen, und denselben semen
Nainen vorgesetzt. und dabey zu verstehen gegeben, dass er diese und
ki'ine andere Edition vor die seine erkenne." Possibly the edition here
referred to contained the lines as Leibnitz gives them, the author chang
ing them in later editions.
PA<;I: 00. lines 7-0. Cf. mitr, p. 00. and note to line 17. ante. p. 731.
ADDITIONS AND CORRECTIONS 737
PA«K 99, note 1. Add: The Chronicon, 379-468, :? also found in
M. Bouquet, Sec. hist. Gaules, new ed., Paris, 1809-1880, 19 vols., fol..
Vol. 1, p. 012; A. Duchesne, Hint. Franc. Script., 1, 183; Migne, Patrol,
s. Lett., 74, 075.
PAGE 100, lines 10, 17. '-The knowledge of being is wrapped up in
that knowledge which we have of ourselves." Cf. New Essay*, Bk. II.,
chap. 27, § 9, Th., infra, pp. 245 sq., and note to p. 247, lines 7-9, infra,
p. 700. Also Kant's doctrine of the categories, to which Leibnitz's
thought at this point is very closely related. Our self-consciousness gives
us an immediate knowledge of being, i.e. of our own particular being,
but not yet the concept of being or substance in general nor any " eternal
truth." What is given is an internal experience, whose essential and
necessary content, implications and full significance are reached only after
profound and protracted thought.
PALI; 101, note 1. The following changes or corrections are to be made
iu this note : In line 23, instead of "Appendix," read: Duncan, 37-40.;.
in line 25, after "Math, tichrift., 0, 234 sq.," insert : trans.. Appendix.
infra, pp. 070-092 ; in line 27. instead of "Appendix," read: Duncan.
71-80; in line 28, instead of " Appendix." read: Duncan. 112-120 : in
line 30. dele " trans., Appendix " ; line 5 from bottom, "As Leibnitz was
occupied." etc., cf. infra, p. 531, note 2, 1JT 2, 3. The statement made
in these two notes would probably more nearly represent the truth in the
matter if made thus: "As Leibnitz was occupied with the composition
of his >New 'Essays1 from 1700-1704, and with their revision until the
end of 1707, and perhaps later (cf. Gerhardt's Introduction to the k New
Essays.' ante, pp. 8, 9, and Leibnitz's Correspondence with Coste, Ger-
liardi. Li'ihniz. philos. Schrift.. 3. 377 *q., especially 391-400) the relative
date." etc.
P.\«.i: 103, line 7. " Witsen." Nicolas Witsen, c. 1040-1717. Dutch
ambassador at the Russian Court, alderman and burgomaster at Amster
dam, published Architectonica nautica nov-antiqua, Amstelod.. 1071 ;
Xoor<!-(jn. Oost-Tartarye, mat Landkaerten, beschrecen, getckent, etc.,
~ vols.. fol.. ib., 1092 and 1705. For Witsen's correspondence with
Lt-ibnitz, cf. Dutens, 0, Pt. II., 199-203 ; Foucher de Careil, (Enures df
Leibniz, 7. 450, 453-459, 404.
PA<;K 103. line 8, "Barantola." The old name for Lhasa, the capital
of Thibet. Cf. Dutens, 0, Pt. II., p. 201.
PA<;K 103, note 2. Add: Chap. 3 in Fraser's Locke's Ksscty.
PA<;I: 103, note 3. Add : Fraser's Locke's Essay, 1, 99.
PA<:K 105, note 1. Add: Cf. Fraser's Locke's Essay, 1,109. Eraser
numbers 21, and states in his note that the section was added in the
second edition
PACK 108, note 2, line 5 from bottom. Instead of " Vol. 3," read :
III.. 2 [Vol. 0].
738 LEIBNITZ'S CRITIQUE OF LOCKE
PAGE 109, note 2. Cf. ante, p. 733, note to p. 68, line 7 from bottom.
Leibnitz regards each monad, and especially the human soul, as a mirror
of the universe. So far as the ideas are clear and distinct, the soul ex
presses the picture of the ideal universe existing in the mind of God as
the " best world" and realized out of his goodness ; so far as they are
confused, the soul is like the phenomenal world in space and time.
PAGE 110, lines 18, 10, "Intrinsic connotations." The intrinsic, inner
activity of every " substantial thing" determines its external activity and
relations to each and all other things. In Leibnitz's view, this activity
consists in representation or is conceived as analogous to representation.
That is, all external change is apparent merely, depending upon that in
ternal change in the condition of substances which we call representation
and which is the real occurrence.
PAGE 112, line 11 from bottom, "Certain author." Locke, Bk. II.,
chap. 1, § 10 (in Coste's translation, which, it will be remembered, was
the one used by Leibnitz as the basis of his critique, 4th ed., Amsterdam,
1742, p. 65, 4 vol. ed., Amsterdam, 1774, 1, 152), says: "Car il s'est
trouve" un Auteur qui ayant lu la premiere Edition de cet Ouvrage, et
n'e'tant pas satisfait de ce que je viens d'avancer contre 1'opinion de ceux
qui soutiennent que V Ame pense toujours, me fait dire, qu'wne chose cesse
(Vexister parceque nous ne sentons pas qu'elle existe pendent notre som-
v/itfiV," etc.; but he does not name the author referred to. In the English
editions of the Essay, for example, Bohn's, Vol. 1, p. 212 ; Eraser's, Vol.
1, p. 129, Locke makes the reference general : " How could any one make
it an inference of mine," etc. Philalethes rightly takes exception to the
opinion thus falsely imputed to the partisans of Locke.
PAGE 118, line 10 from bottom, "Beg the question." Schaarschmidt
has put the argument in logical form thus : "That of which we are not
conscious is not in the soul ; We are often conscious of no ideas ; there
fore, We are often without ideas (or, therefore, often we do not think).
And he goes on to say that, the circle, of which Leibnitz speaks, consists
in the fact that he who so concludes has already put the conclusion in
the major premise in assuming that to have no consciousness of ideas is
the same as to be without ideas (Nichtvorstelleri) or not to think (Nicht-
denken}. The latter statement is false. One can have ideas, and actu
ally does have them, without being directly conscious of his ideas
(VorsteUens). Thus the major premise of that argument is false, and
therefore the conclusion likewise, while the minor is true. According to
Leibnitz, substance is always active — is indeed action itself — thus also
the soul, since for him it is a substance, and since the proper activity of
the soul is to have ideas (das VorsteUen), therefore the soul is always
having ideas (vorstellend) ."
PAGE 118, note 1, line 2. After " Erdmann," add: Janet.
PAGE 119, line 8 from bottom, "Independently of the senses." Cf.
ante, p. 723, note to p. 42, line 10, ad Jin. ; p. 725, note to p. 44, line 13 ;
ADDITIONS AND CORRECTIONS 739
p. 733, note to p. 68, line 20. In accord with Leibnitz's principle of the
absolute spontaneity of substances, all activity, that of the soul as well,
springs out of the depths of its own being.
PAGE 119, note 1, line 2. After " Erdmann," add: Janet.
PAGE 120, line 6, " Ex professo." Schaarschmidt says the term Ex
professo is a technical expression occurring in classical literature (for
example, Seneca and Quintilian) , which signifies : in a positive, precise
way, in a pronounced or aforementioned manner. Leibnitz means to
say, hitherto have we each set forth and justified his own speculative
point of view (erkenntniss-theoretischen Standpunkt} ; now we come to
the consideration of some classes of ideas in which we shall more than
hitherto agree with each other.
PAGE 120, note 1. After " Erdmann,1' add: Janet.
PAGE 121, note 1. After " Erdmann's," add : Janet's.
PAGE 122, lines 1, 2. "The membranes receive the sensation," etc.
Cf. Leibnitz's letter to Amauld, April, 1687 (Gerhardt, Leibniz, philos.
Schrift., 2, 90, 91): "«Les nerfs et les membranes sont des parties plus
sensibles pour nous que les autres, et ce n'est peutestre que par elles que
nous nous appercevons des autres, ce qui arrive apparemment, parceque
les mouvemens des nerfs ou des liqueurs y appartenantes imitent mieux
les impressions et les confondent moins, or les expressions plus distinctes
de 1'ame repondent aux impressions plus distinctes du corps. Ce n'est
pas que les nerfs agissent sur 1'ame, a parler metaphysiquement, mais
c'est que 1'un represente 1'estat de Pautre spontanea relatione," i.e. "The
nerves and the membranes are the parts more sensitive for us than the
others, and it is perhaps only by them that we perceive the others, which
happens apparently, because the movements of the nerves or of the fluids
belonging thereto imitate better the impressions and confuse them less,
now the more distinct impressions of the soul correspond to the more
distinct impressions of the body. Not that the nerves act upon the
soul, to speak metaphysically, but that the one represents the state of
the other by reason of a spontaneous relation.'1'1 Modern psychological
investigation and experiment prove that the end-organs rather than the
nerves "receive the sensation," or, in modern phrase, 'are acted upon
directly by the stimulus,' the character of the sensation depending upon
the peculiar structure of these different end-organs, and not upon the
nerves. The formerly held doctrine of the "specific energy of the
nerves" as being the cause of specific sensations, or as 'accounting for
the quality of the sensation ' — a doctrine which, according to Schaar
schmidt in his note to the passage (Erlauterungen z. d. Neuen Abhand-
lungen u. d. menschlich. Verstand v. G. W. Leibniz, Berlin, 1874, J. H.
v. Kirchmann's Philos. Bibliothek, Bd. 56, Erlauterung, 92, p. 27) con
tradicts Leibnitz's statement in the text, — is now given up. Leibnitz's
statement, while partly true, is nevertheless incomplete. He is right in
stating " that tastes make themselves known to some extent through the
740 LEIBNITZ'S CRITIQUE OF LOCKE
nose, by reason of the connection of these organs," —modern experiments
having proved taste and smell to be interdependent in their action in sen
sation, — but wrong as to the assistance of the teeth in the transmission
of sound, the teeth not being ordinarily concerned in the process. If by
"membranes" Leibnitz meant "end-organs," his statement, with the
exception of the part regarding the hearing, would be correct, and his
theory exhibit a remarkable degree of insight and foresight and of ap
proximation to the modern view of the subject. But this interpretation
of his language seems on the whole inadmissible, "membranes" with
him signifying probably the skin and the muscles, so that, while we may
not justly regard him as having attained the fulness and completeness of
the modern understanding of the sensation-process, we may yet justly
attribute to him a measure of insight into, and foresight of, what through
subsequent investigation and experiment has been proved to be its true
nature.
PAGE 122, Chap. IV., § 1, line 5, "Solidity." On Locke's idea of
solidity, cf. Lasswitz, Gesch. d. Atomistik, 2, 505-508.
PAGE 123, note 3. After " Erdmann," add: Janet.
PAGE 124, lines 9, 10 from bottom, "The scholastic conception of the
air." Cf. New Essays, Bk. I., chap. 1, § 18, Th., ante, p. 83, lines 11, 12.
On "rarefaction and condensation," line 12 from bottom, cf. Lasswitz,
Gesch. d. Atomistik, Vol. 1, passim.
PAGE 125, last line of text and note 1, " Animant." Some time after
the text and note were in type, I came upon Leibnitz's letter to Leuwen-
lioek, " Sur PAimant," cf. Dutens, Leibnit. op. om., 2, Pt. II., 92-94. In
the correspondence, in Latin, of Leibnitz with Des Bosses there is con
siderable allusion to the Magnet, cf. Gerhardt, Leibniz, philos. Schrift.,
2, 437 (Postscript to Letter of Leibnitz to Des Bosses, February 5, 1712).
492-495, 497-498 (Leibnitz* to Hartsoeker, April 29, 1715, in French).
505, 513 (Response de Mr. Hartsoeker, in French). As from this corre
spondence it is evident that Leibnitz was occupied more or less with the
study of the Magnet, it seems as if the reading of the text should be
"aimant," and the translation accordingly "magnet," and thus the view
expressed in the last sentence of note 1, ante, p. 125, is, con firmed. Janet
also reads "aimant." Cf., also, a rough draft of letter of Leibnitz to
Peter the Great, January 16, 1712, Foucher de Careil, (Euvrex de Leibniz,
7. 507, and a rough draft of a memorial of Leibnitz concerning the study
of languages and the observation of the variation of the magnetic needle
in the Russian Empire, (hid., 519, 531 sq. ; also. Observations iiber die
M<i(jii<>t-Xadel, ibid., 562 sq.
PAGE 126, line 1, " Vacuum." That is, the effort of all bodies, particu
larly air and water, to fill up empty space. The doctrine of the universal
attraction of all bodies has put an end to this false notion of " the fear of
a vacuum " — horror vaciti. On the vacuum, cf. Lasswitz, Gesch. d. Ato-
misfik, passim.
ADDITIONS AND CORRECTIONS 741
PAGE 127, note 2. Add : Leibnitz's correspondence with Guerike, cf.
Gerhardt, Leibniz, philos. Schrift., 1, 89-112.
PAGE 129, line 1, " The view of the Cartesians." Janet, (Euvres phito*.
de Leibniz, 1, 95, note 1, refers to Descartes, Prin. Philos., II., § 4.
Cf. Veiteh's trans., pp. 233-234.
PACK 129, line 0, " Disagreement." Schaarschmidt remarks on this
chapter as follows : "In this chapter on Solidity the antithesis of the
Lockian and Leibnitzian view comes out with great acuteness. Locke,
starting out from Sensualism, affirms that solidity is the most real property
of bodies, a statement which, if logically developed, must lead to the as
sumption of hard impenetrable atoms. On the other hand, Leibnitz rightly
maintains that all the properties of the body which Locke derives from
solidity may be won without the assumption of a space-filling and im
penetrable first being, and that ' solidity ... is conceivable by pure
reason, although the senses furnish the reason with the means of proof
thereto.' " He also compares, on the atoms, Leibnitz's Nonrwn zysteme
d<> la nature, § 11 sq.
PAGE 129, last liue, "Demonstration." This view of Leibnitz, as
developed by Christian Wolf, became the seed from which sprang the
Kantian doctrine of the categories. «
PAGE 130, line 13 [Chap. 7, line 6], "Idea of existence." Schaar
schmidt says : " The validity of this protest is clear, although Sensualism
until the present time has not allowed itself to be brought back from the
Lockian view. The concept of existence springs from the source of self-
consciousness. not from the sensitivity. Sense-perception is as such first
possible, after we have won the concept of existence from self-conscious
ness, and now after the analogy of our own being have placed it under
the sense-phenomena for their explanation."
PAGE 130, note 1. Add: Schaarsclrtnidt translates: " Inbetracht-
nahme des Daseins."
PAGE 130, note 1. Add : Dr. E. G. Robinson, President of Brown
University, and Professor of Philosophy, 1872-1889, gave in his MS.
Lectures to his classes on Psychology the following account of Cnn-
CONSCIOUSNESS
" As this is the one controlling source of all our knowledge of mind, it
is indispensable that we determine as precisely as we can just what we
understand by it.
" It is manifest at the outset that consciousness is the invariable accom
paniment and necessary condition of all actual knowledge and of every
cognitive act. It is itself never an act but always a state of mind without
which mental acts are impossible and which itself is possible only through
742 LEIBNITZ'S CRITIQUE OF LOCKE
cognitive acts, and this is true whatever the acts of cognition may be,
whether relating to objects in the external world, to the bodily organism,
or to strictly subjective thought and feeling.
"It is evident, therefore, that we cannot with Reid regard conscious
ness as a faculty. A faculty can be called into exercise, consciousness
cannot be, but always exists as a condition of the exercise of a faculty.
Neither can we regard it as an intuitive idea, a regulative notion. Aji
intuitive idea can exist only in consciousness. If consciousness be an
intuitive idea, it must itself exist as the condition of its own existence.
Neither can we regard it as identical with feeling, as sundry sensational
ists do, since feeling can exist only in consciousness. Nor yet again can
we with Sir William Hamilton regard consciousness as the genus of
which cognitive acts are the species, as the complement of the cognitive
faculties.1 A genus can exist only as made up of species. The distinc
tion between consciousness and cognition is, according to their definition
when analyzed, only verbal and not real. Consciousness can be neither
a special faculty, nor an intuitive idea, nor a distinct species of knowl
edge, nor the complement of the cognitive faculties, but is that within
which all ideas must exist, any species of knowledge be acquired, and
every faculty be exercised.
" It cannot, accordingly, be correct to define consciousness as the soul's
knowing that it knows,1 or ' the power by which the soul knows its own
acts and states,' '2 or the power to know that it is itself that knows.8
But consciousness is rather the souVs actual knowing with itself that it
knows, that is, is that relation to itself into which the ego is brought by
cognition of any object other than itself, is the ego as subject commun
ing with itself as object through the mediation of some object distinct
from itself. It is not a power of the soul but is a state,4 a condition, a
function of the soul which always necessarily accompanies any normal
or voluntary exercise of the soul's powers. Speaking figuratively and
popularly, it is the mind's illumination of itself by its own action.
"That the foregoing is a correct account of consciousness seems
evident:
"1. From the difference between cognition and consciousness and the
relation of the one to the other. Cognition is a voluntary act of the ego,
and consciousness is an involuntary state or condition of the ego which
always accompanies its cognitions, and neither one can by any possibility
exist without the other. Simple cognition is only a given correlation of
subject and object ; whereas in consciousness, which must always accom-
1 Sir William Hamilton, Metaph., 133 sq., 143 sq. , Amer. ed. ; Discussions,
p. 54, Amer. ed.
'2 President Noah Porter, Hum. Intellect, p. 83.
3 President Mark Hopkins, Outline Study of Man, p. 107.
4 In the oral exposition of this passage, Dr. Robinson remarked in substance
as follows: "A 'state' is usually considered as something inert, stable, in
active ; but not so with Consciousness. Consciousness is an active state.
' State ' is preferable to 4 act,' as the latter implies volition. Consciousness is
an involuntary state or condition of the ego."
ADDITIONS AND CORRECTIONS 743
pany cognition, the knowing subject is in and by the cognitive act
brought into correlation to itself as coexistent or conjunctive object.
••2. The very word consciousness, which all are agreed in using, implies
in its composition a partnership and an intercommunication between self
as knowing subject and self as known object, an intercommunication
which occurs momentarily and continuously in every cognitive act.
Whatever may have been the origin of the word, whether with philoso
phers or the unlettered, it etymologically vindicates the view of conscious
ness here given.
"3. It is admitted on all hands that knowledge is impossible without
consciousness. But if consciousness itself be a distinct kind of knowl
edge, whether generic or specific, then since all knowledge is possible
only in consciousness, consciousness itself must have its conditioning
consciousness and so on ad injinitum. But not only does the conscious
ness of every individual being have an absolute beginning, but every
given instant of consciousness is as distinct and separate from the
preceding as is every act of cognition from its preceding, and every
given instant of consciousness is dependent on some given act of cogni
tion. Consciousness, therefore, is not an act of cognition, nor a power
to cognize, but is the simple reflex action of the ego upon itself in its own
acts of cognition ; and it cannot be the mind's power to know itself or to
know that it is itself that knows, since it is a state or a relation of the ego
to itself which is always dependent on the exercise of the power to know.
l'If what has been said be true, then it is evident that consciousness,
although always inseparable from bodily sensation, is predicable only of
mind as active intelligence or intellect. It is by the mind alone as the
perceiving, thinking power of the soul that any of the soul's energies,
cognitive, cogitative, emotive, volitional, can be brought into exercise or
continued in action, and since it is only by the exercise of these energies
that consciousness exists, it is of the mind alone, the perceiving and
thinking power of the soul, that consciousness is predicable. Again, it
also follows that there can be but one kind of consciousness, that it is
always spontaneous, the invariable and necessary accompaniment of cog
nition, that is, it always accompanies cognition whether the cognition
be of objects external or internal. It may vary in degree according to
degrees of attention in acts of cognition, but it never changes from itself
into consciousness of another kind.
;' The so-called self-consciousness or the reflective, acquired, philo
sophical consciousness, is nothing else than that act of mind by which
the ego itself, its acts or states or its consciousness are made objects of
attention. This does not differ from any other act of cognition and
knowledge. It furthermore, like every other act of knowledge, is always
accompanied by a consciousness of the act, and the consciousness of our
consciousness, when it is made an object of attention and knowledge, is
just as clear as the consciousness we have when we perceive an external
object or when we make a percept, a concept, or an inward emotion an
object of attention and scrutiny."
744 LEIBNITZ'S CRITIQUE OF LOCKE
THE COMPONENTS OK CONSCIOUSNESS AND THEIR REALITY
" When we make consciousness an object of attention and analyze it
into its component parts, we find it always to consist of three distinguish
able elements, namely : the ego cognizing, the object cognized, and the
communion of the ego with itself in the cognitive act ; tjiat is, we find the
.soul communing with itself in the act of knowing something which is not
itself. But these three elements, when themselves analyzed, reveal the
existence of but two distinct quantities or entities, the ego and the object
of its knowledge. Out of these two factors, subject and object, carefully
analyzed, come directly or indirectly the entire materials of mental phi
losophy.
" As to the real existence of these factors of consciousness, the subject
and its objects, we may begin with the objects. If there be any doubt as
to the reality of the mind's objects, the so-called subject-objects, whether
they be sensations, feelings, perceptions, ideas, volitions, or whatever else
simple or complex, there is still stronger reason for doubting the existence
of an external world from which as cause or occasion these subject-objects
have sprung, and reasons stronger still for doubting the existence of our
doubt. If mental objects be unreal, doubt has no existence. The truth
is, if there be any reality anywhere it is in the mind's own acts of subjec
tive cognition.
•' In like manner, if the object in consciousness has a real existence,
still more indubitably real is the existence of the personal ego that knows
the object in consciousness. This is evident in three ways :
"First. We are conscious only while one of our mental faculties or
powers is in exercise. In the act of its exercise the ego immediately
intuits itself as exercising its own energy. Self immediately cognizes
self as active in every successive moment of consciousness.
t% Second. It is plain that the objects cognized on which the existence of
consciousness is always dependent, even the most subjective and subtle of
them, are clearly distinguishable from the ego that cognizes the object.
In fact, no object in consciousness is ever cognized unless the cognizing
self clearly distinguishes between itself and the object. Such discrimina
tion cannot take place unless the ego that makes it has an indubitably
real existence.
'• Third. The existence of memory proves the real existence of the per
sonal ego. Consciousness is a succession of instants each of which is
distinct from the preceding and following and each of which changes
with the ever-changing objects of cognition and thought, and yet these
vanishing instants so leave their traces on the personal ego that it can at
will recall long series of them. Thus memory not only proves the exist
ence but the persistent identity of the ego that has an object of thought
with its accompanying consciousness to-day which it can reproduce to
morrow, the next day, and with indefinite frequency thereafter.
-Finally. The real existence of object and subject being indubitably
established, it necessarily follows that the existence of consciousness,
ADDITIONS AND CORRECTIONS 745
within which both subject and object are found, and consequently its
trustworthiness as a source of knowledge in Psychology, must be unhesi
tatingly admitted.'' (Lects. on PsychoL, MS., §§ 12, 13, as given to the
class of 1884.)
REQUISITES AND DIFFICULTIES IN CONSULTING CONSCIOUSNESS
'• That is, in practising the so-called self-consciousness.
"First. Requisites: It is necessary that there be close and concen
trated attention, patience and persistence in observation, frequent and
varied observations, careful discrimination between different classes as
well as between different species of the same class of mental phenomena ;
that each particular phenomenon be analyzed and traced to its cause or
causes ; that there be a distribution of phenomena according to their
nature and causes so far as these can be ascertained.
•• But with the utmost care, attention, and discrimination in the anal
ysis and classification of the phenomena given in consciousness, there is
a constant liability to error. The nature, relations, and causes of the
phenomena to be observed are many of them so subtle and obscure that
diversity and even conflict of view may be inevitable, but the disagree
ments, it must be remembered, turn chiefly on the theories respecting the
origin of the phenomena and their relation to realities and not on the
reality of the existence of the mental phenomena themselves.
••Second. Difficulties: The observation and examination of the phe
nomena of consciousness, however, as compared with the observation
and examination of phenomena in the external world, is attended with
various, and to inexperienced minds with serious, difficulties. Thus :
'• («) So large a portion of early life is spent among and in the obser
vation of the phenomena of the outer world that it is difficult for many
persons to acquire the habit of accurate observation of the subjective
phenomena of mind. This difficulty is heightened :
•' (fr) By the necessity the conscious subject is under of becoming the
object of its own observation, the necessity of compelling himself to act
and to observe himself at the same instant. Upon the phenomena of t he-
outer world the mind can concentrate an undivided attention, but when
the mind makes its own action an object of attention there is requisite
the double effort to produce mental movement and to observe oneself
in the process, the result being at best but constrained and halting action
of which from divided attention we can catch only hasty and imperfect
views.
" (c) Subjective acts and states occurring in rapid succession can be
observed only instantaneously, while most objects of sense remaining
comparatively permanent in form can generally be examined repeatedly
and at leisure. The most evanescent of physical phenomena give ample
lime for observation in comparison with the most enduring phenomena of
mind.
" u?) Every individual consciousness is isolated from that of every
746 LEIBNITZ'S CRITIQUE OF LOCKE
other, and the report of no one's consciousness, notwithstanding the
unanimity in the deliverance of all consciousnesses, can be accepted or
even understood by another without a personal scrutiny of his own ;
whereas in the natural sciences there may be many or few observers, and
their reports can be understood and received without personal experiment.
" (e) The objects of consciousness are many of them complex in them
selves and their causes and subtle in their relations to one another ; they
therefore are much more difficult of observation and require much more
careful discrimination in observing them than objects in the external
world, the mechanical and chemical origin of which are at once and pal
pably discernible." (Lects. on Psychol, § 14, e'd. of 1884.)
To the above, as presenting more completely Dr. Robinson's view of
Consciousness, — -a subject which "he regarded as fundamental to all
order and rectitude of thought" in Psychology, and on which "he ex
pended much time and thought" in perfecting his conception and its
statement, — may be added what he dictated to his classes on the question :
" CAN THERE BE AN UNCONSCIOUS MODIFICATION OF MlND ?
" That is, can there be mental processes and the mind itself unaware of
them '? The answer must manifestly depend on the meaning attached to
the word mind. If by mind be meant the thinking personal essence, or if
it denotes the co-ordinated psychical forces which constitute personal
being, there can be no good ground for doubting that there may be
unconscious modifications of both its states and its powers. There are
depths in the potentialities of the personal being which consciousness
never reaches. Consciousness knows nothing of the inner sources of
energy whence thoughts, feelings, desires, and volitions emanate, but
only of thoughts, feelings, desires, and volitions after they have taken
form in the mind. It is upon the existence of these that consciousness
depends, and of their existence alone can consciousness inform us. There
may therefore be modifications of states of soul, increments and diminu
tions of intellectual and moral power, and losses of intellectual possessions
of which we may be unconscious and of which we may remain uncon
scious till we learn them from unwonted phenomena.
"So also thoughts and accompanying states of consciousness often
spring from instinct and hereditary bias which have long lain latent and
have existed and operated below consciousness. Instances of knowledge
lost under some given condition of the brain and restored under other
cerebral conditions are examples of the same kind of unconscious changes.
Every species of mental action is more or less dependent on the state of
the brain, but to ascribe these changes to unconscious cerebration is to
assume that thought is the equivalent of physical force, is both the quan
titative and qualitative product of the brain alone, rather than the product
of an active agent which uses the brain, and it is an assumption for which
there is no sufficient ground.
1 "But if by mind be meant the soul's acquisitive and cogitative powers.
ADDITIONS AND CORRECTIONS 747
the intellect, the intelligence, the question whether it may not be uncon
sciously modified is equivalent to the query whether there may not be an
unconscious mental act or (which is the same thing) an unconscious state
of consciousness, a contradiction of terms. Every modification of mind,
in the sense of the word mind here under consideration, must be by some
mental act. But any mental act in order to be such must be a conscious
mental act. Cognition and consciousness always coexist. An uncon
scious modification of mind would necessitate a mental act of which one
was unconscious.
" The facts often cited in proof of an unconscious modification of mind
do not seem to warrant the conclusions drawn from them ; for instance,
acts performed in obedience to any established habits, single but synthetic
visions of complex objects, sudden and apparently unaccountable thoughts,
sudden and mysterious recollection of long-forgotten persons and events,
the apparently simultaneous carrying forward of several trains of
thought. All these may be instances, not of unconscious cerebration or
of unconscious modification of the mind, but of mental movements, the
successive steps of which are too occult or too rapid and minute for the
mind in the study of itself to follow. In compound and complex mental
processes it is possible that simple steps may be so inadvertently taken as
to be apparently taken unconsciously ; but an analysis of the process will
show that while the degrees of consciousness may be indefinitely numer
ous, running down to the lowest stages of latent or sub-consciousness,
yet unconsciousness is so far removed from ever so low a degree of con
sciousness as to be separated from it by an impassable chasm. As there
are many degrees in life but none in death, so there are degrees in con
sciousness but none in unconsciousness." (Lects. on Psychol., § 20, ed.
of 1884.)
PAGE 138, note 1. Add : For the letter of Molyneux here referred
to, dated March 2, 1693, cf. Locke's correspondence with Molyneux, in
Locke's Works, 9, 34, 12th ed., London, 1824, 9 vols. 8vo. Berkeley, An
Essay toward a New Theory of Vision, §§ 132, 133, Eraser's ed., Vol. 1,
pp. 90, 97, refers to it ; also Locke, Philos. Wks., Bonn's ed., 1, 257-258,
note t. -On the relations of Locke and Molyneux, cf. Eraser, Locke,
Blackvvood's Philos. Classics, Edinburgh and Philadelphia, 1890, p. 234 sq.,
the letter referred to, p. 238. Molyneux died as a result of a journey,
undertaken when ill, to see Locke.
PAGE 139, lines 17-20, "In this case . . . united with that sense-knowl
edge with which touch has before furnished him." Cf. " The Mentor,"
a monthly, published by the Alumni Association of the Perkins Institu
tion for the Blind, Boston, Mass., U.S.A., Vol. 2, No. 3, March 1892, pp.
81-86, -'Sculpture by the sense of Touch," giving an account of a blind
sculptor, Johnson M. Mundy, whose sight began to fail in his youth and
slowly but surely grew less, until it practically vanished entirely. He
learned the sculptor's art between the ages of 22 and 29, and practised it
for twenty years till the loss of sight compelled him to give it up. Unable,
748 LEIBNITZ'S CRITIQUE OF LOCKE
however, long to endure " the monotony of an idle and useless existence '"
and lk with unabated aspiration and fondness for his art,"' he resumed his
work, performing the actual work of sculpture by the sense of touch. His
last work up to the date of the article here referred to was a heroic statue
of Washington Irving.
PA<;K 144, note 1. Add: Of. Gerhardt, Leibniz, philos. Schrift., 0,
522-528, letter 5 to Sophie Charlotte ("hitherto not published," Gerhardt,
op. <.•?£., 0, 477, note * — he should have said 'published entire,' as Foucher
de Careil, Lettres et opuscules inedits de Leibniz, Paris, 1854, pp. 252-254,
published a fragment of the same), in which Leibnitz subjects Bouhours'
book to a sharp critique. Leibnitz also refers to Bouhours in his letter to
Sebastian Kortholt. Sept. 30, 1708, Kortholt, Leibnit. Epistohr. 1, 282;
Dutens, Leibnit. op. om., 5, 306-307 ; to Fried. Wilhelm Bierling, Oct. 24,
1709, Kortholt, op. <'it., 4, 8 ; Dutens, op. <*Jt., 5, 355 ; Gerhardt, Leibniz,
philos. Schrift., 7, 487: "Bouhursius mihi conteintu vindicandus, nee
verbis a Germanis, sed rebus ret'ellendus videbatur." Cf., also, Dutens,
<>p. fit., 5, 190: " Mediocris vir fuit Bouhursius, qui neglecto religion is
sua>, cui se addixerat, habitu. Damaretum quendam effingere, et foemi-
neam elegantiam exprimere satagebat."
PACJK 147. line 2 from bottom, "Modes." Cf. Descartes, Prin. Philos.,
Bk. L. § 50, ed. Cousin, 3, 98 ; Veitch's English trans., 217 ; German
trans, by J. H. v. Kirchmann, 2d ed., Heidelberg, 1887 (Bd. 20 of his
Philo*. Bibliothek), p. 28: "Lorsque je dis ici fagon ou mode, je
n'entends rien que ce que je nomine ailleurs attribut ou qualite. Mais
lorsque je considere que la substance en est autrement disposee ou diver-
sin'ee. je me sers particulierement du nom de mode ou fagon ; et lorsque.
de cette disposition ou changement, elle pent etre appelee telle, je nomine
qualities les diverses fagons qui font qu'elle est ainsi nominee ; enfin.
lorsque je pense plus ge"neralment que ces mt)des ou qualitfe sont en la
substance, dans les conside"rer autrement que comme les de"pendances de
cette substance, je les nomme attributs. Et, parceque je ne dois cnncc-
voir en Dieu aucune variete ni changement, je ne dis pas qu'il y ait en
lui des modes ou des qualitds, mais plutot des attributs ; et meme dans
les choses cree'es, ce qui se trouve en elles ton jours de meme sorte, comme
I'existence et la duree en la chose qui existe et qui dure, je le nomme
attribut, et non pas mode ou qualite." Of., also, Xeif Essays, Bk. II..
chap. 30, § 4, infra, p. 270, and note to p. 277. line 8. infra, p. 703.
r.\uK 147, note 1. Dele ''Appendix, p. ." and substitute " Duncan,
71-80." Cf., also, New Essays, Bk. IV.. chap. 10. § 7, 'I'll., ad Jin., infra,
p. 505, $ 9. Th.. p. 507.
P\<iK 149. line 15 from bottom, k>The shortest great-arc of a circle."
The French text is : '• La longueur du plus petit grand-arc de cercle," etc.
PA<;K 150, line 13. '• Buratini." Cf. Dutens, Leibnit. op. om., 6, Pt. I.,
319: -• (-iravitt*, Anglns. in de;scrii)tione vEgypti apud Thevenot, Vol. 1,
p. 14. mentionem facit, Titi Licit Bnratini, jeune homme Venitien fort
ADDITIONS AND CORRECTIONS 749
spiritual, qui etoit dans la compagnie. Thevenot in margine annotat :
Kuratini est maintenant maitre de la monnoye du Roi de Pologne, et c'est
de lui que 1'on vit il y a dix ou douze ans un modelle d'une machine pour
rolf.r."
PAGE 153, line 7, "Lessius." Leonard Lessius, 1554-1623, a Flemish
.Jesuit, was Professor of Philosophy at Douay, and of Theology, 1583-1623,
at Louvain. He opposed the doctrine of grace of Thos. Aquinas, and was
charged with favoring Semi-Pelagianism. He was well acquainted with
theology, law, mathematics, medicine, and history. For two of his
Opera, cf. Migne, TheoL cur. compl, 3, 787 ; 15, 445. Janet, CEuvres
philos. de Leibniz, 1, 120, note 1, states that he was a celebrated casuist,
often cited in Pascal's Provinciates, and adds that of his ethical works
the chief is the De jKstitia et jure (Migne, op. cit., 15, 445) ; and that of
the theological works we have De perfectiotiibus moribusque divinis ; De
libertate arbitrii et prcescientia Dei; De summo bono ; De Providentia
numinis.
PACK 154, line 13, "Accidents or abstracts." The strong contrast
between Locke's and Leibnitz's philosophies conies here again to the front.
Locke regards substance as a mere creation of thought, a subjective expe
dient of the understanding which "invents" it as a unitary support to,
or bearer of, the accidents. Leibnitz looks upon the " substance-concept
as the suitable expression of the idea of the actual, to which we refer
back the accidents. Every phenomenon as such, in his view, presupposes
an actual being, since through such an actual being the phenomenon is
first possible. Substance, accordingly, is in the case of all phenomena that
which is constantly to be presupposed, the non-irrational (Nickt-nichtzn-
denkende}, but in no sense a mere auxiliary concept of only subjective
validity." — Schaarschmidt. Leibnitz is in the direct line of Hegel in his
emphasis of the concrete rather than the abstract.
PAGE 154, line 4 from bottom, " Indefinite." Cf. Descartes, Prin. Philos.,
Pt. IT., § 21, ed. Cousin, Vol. 3, p. 138: "Nous saurons aussi que ce
monde, ou la matiere etendue qui compose 1'univers, n'a point de bornes,
parceque, quelque part ou nous en voulions feindre, nous pouvons encore
imaginer au-dela des espaces inde"finiment etendus, que nous n'imaginons
pas seulement, mais que nous concevons etre tels en effet que nous les
imaginons ; de sorte qu'ils contiennent un corps indefinement etendu,"
i.e. We know that this world, or the extended matter which composes the
universe, has no limits because, should we wish anywhere to feign such
limits, we can still imagine beyond spaces indefinitely extended, which we
do not imagine only, but which we conceive to be in fact such as we imag
ine them, so that they contain an indefinitely extended body.
PA<JE 154, note 1, line 4. Instead of "Appendix," read: Duncan, pp.
68-70 ; line 7, ditto, pp. 71-80 ; line 10, ditto, pp. 112-126.
PAGE 155, line 26, " Motion." Cf. Leibnitz's 4th letter to Clarke, ad
fiii., Gerhard t, 7, 377 ; Erdmann, 758 ; Jacques, 2, 437 ; Janet, 2, 640 ;
750 LEIBNITZ'S CRITIQUE OF LOCKE
trans. Duncan, 253 ; 5th letter to Clarke, § 22, Gerhardt, 7, 394 ; Erd-
mann, 765 ; Jacques, 2, 450 ; Janet, 2, 654 ; Duncan, 259.
PAGE 156, note 1. Phys., VIII. [or H], 6, 258b 10: cirei 5£ Set Klmi<riv
dfl eivai /ecu JJ.T) StaXetTretj', avdyKr) etvai TL o trpCiTov /am, ftre ev efre irXeiw,
/ecu TO Trp&TOV KIVQVV O.KIVTJTOV.
PAGE 157, note 1. Add: QvaiKrjs 'A/cpodo-ewj, A, 11, 219b 1 : TOVTO yap
fffriv 6 %p6vos, dpifl/AOS /eii'Tjtrews Kara TO irpdrepov /ecu varepov. OVK &pa Klvr/cris
6 x/>6i/os d\X' rj dpidfjibv exet 77 Klvrjffis. &V<TIKTJS 'A/epoclcrews, A, 11, 219b 8 : 6 5£
Xpbvos earl rb apid/j-oiJiuifvov /cat oi>x V o,pi6fj.ovfj,ev. Cf. Zeller, Philos. d.
Griech., 3d ed., 1879, II., 2 [Vol. 4], 402.
PAGE 158, note 1. Add : Spinoza regards all determination as a nega
tion — Omnis detenninatio est negatio — of this originally posited or
necessarily presupposed absolute. Hegel likewise in his Logik maintains
essentially the same position as Leibnitz, so that Leibnitz may rightly be
said to be in the direct line of the philosophical development culminating
in Hegel. Cf. Wallace, The Logic of Hegel, 1st ed., 1874 ; 2d ed., revised
and augmented, Oxford, Clarendon Press, 1892-1894, passim.
PAGE 160, line 9, "Transcendent." Janet, (Euvres philos. de Leibniz,
1, 128, in his note to this passage, says: "Expressions of the scholastic
mathematical language, rarely employed to-day. The surd (le sourd) is
the incommensurable, for example, v'2 ; le rompu — the broken — is the
fraction, as J ; the transcendent is that which cannot be calculated by a
limited number of arithmetical operations, for example, log 3. These
three terms are comprised between two whole numbers.1'
PAGE 162, note 1. Add: Locke's Essay, ed. Eraser, 1, 295, line 9 from
bottom.
PAGE 162, note 2. Add: Cf. the note of Foucher de Careil, Sur Jen
trois sens du mot infini dans la philosophie de Leibniz, youvelles Lettres
et Opuscules inedits de Leibniz, Paris, 1857, pp. 404-407 ; also A. Penjon,
De injinito apud Leibnitium, Paris, 1878.
PAGE 162, note 3. Add: Locke's Essay, ed. Eraser, 1, 277, line 14.
PAGE 166, note 1. Add : Locke's Essay, ed. Eraser, 1, 300, line 10.
PAGE 167, note 1. Add: The definition referred to runs as follows:
"Amnre autem sive diligere est felicitate altering delectari, vel quod
eodem redit, felicitatem alienam adsciscere [Erdmann — asclscere] in
suam. Unde difficilis nodus solvitur, magni etiam in Theologia momenti,
quomodo amor non mercenarius detur, qui sit a spe metuque et omni
utilitatis respectu separatus : scilicet quorum utilitas [Erdmann — felici-
tas] delectat, eornm felicitas nostram ingreditur, nam quse delectant per
se expetuntnr." Cf. Dutens, Leibnit. op. om., 4, Pt. IV., 295 ; Erdmann,
118, b. The entire preface to the Codex juris is given in Dutens, op. cit.,
4, Pt. III., 287-328.
ADDITIONS AND CORRECTIONS 751
PAGE 168, note I, ad fin. Add : Infra, pp. 177 sg., 188. Also, Theo-
dicee, III., § 404, Gerhardt, 6, 357 ; Erdinann, 620 ; Jacques, 2, 300 ;
Janet, 2, 402. Cf., also, J. H. v. Kirchmann, Erlauterungen zur Theo-
dicee von Leibniz (Bd. 80, of his Philos. Bibliothek, Leipzig, 1879),
Krlauterung, 264, pp. 145-147.
PAGE 172, line 4 from bottom, "Displeasure." Schaarschmklt says
that neither Locke nor Leibnitz have yet reached the distinction between
emotion and passion, as appears from the language of both ; and that
Kant first grasped the distinction and attempted to determine it more
accurately.
PAGE 174, note 1. Add: Phys., T, 201a 10: -f] TOV 5vvd/j.ei 6i>ros evre-
, 77 TOIOVTOV, Kivrjo~is eo~Ti.v, olov TOV /j£v dXXotwroC, 77 dXXoiwr6i', aXXotunm,
av%r)Tov /cat TOV AvriKeiftevov 0#troO (ovdtv yap 6vo/jia KOLVQV err'' d/j.(po'ii>)
/cat <j>0i(TLS TOV 5e yevrjTov /cat <f>6apTOv yti>eo~is /cat cftdopd, TOV o£ (popyTov
<popd. j\letcipliys., K, 1065b 16: TT\V TOV dwdfj.€L rj TOLOVTOV t&Tiv evtpyeiav
X^w Kcvrja-iv. Cf. Zeller, Philos. d. Griech., II., 2 [Vol. 4]. 351 sr/.,
389 sq.; Wallace, Outlines of the Philos. of Aristotle, § 42, p. 77, 3d ed.,
1883.
PAGE 174, note 2. Add : Translations of the two pieces last referred
to will be found in the Appendix, infra, the Reilage to the letter to Fabri,
pp. 699 sq. • the Specimen Dynamicum, pp. 670 sq.
PAGE 175, line 5, "Idea of power.1' Leibnitz carefully distinguishes
between mere power and force ("Macht" and "Kraft"). Cf. De
primce philos. emendatione, etc., Gerhardt, 4, 469; Erdmann, 122;
Jacques, 1, 453 [in French] ; Janet, 2, 525 [in French]; Duncan, Philos.
Wks. of Leibnitz, 69.
PAGE 175, line 18, "Because of our ignorance." That is, we are thus
far incapable of resolving our sense-impressions, i.e. the simple sense-
qualities, into anything more simple, and are therefore compelled to
regard them as simple presentations, although in themselves possibly
composite and in fact in many cases in indirect ways shown to be so.
Cf., also, Xew Essays, Bk. III., chap. 3, § 18, Th., infra, p. 317, and
note 2.
PAGE 175, line 24, "Primitive truths." Cf. New Essays, Bk. I., chap.
1, and Bk. IV., chap. 2, infra, pp. 404 sq.
PAGE 176, line 13 from bottom, " Casati." Paolo Casati, 1617-1707,
a learned Italian Jesuit, who taught mathematics and theology at Rome,
and was said to have converted Queen Christiana, of Sweden, to the
Catholic faith. On his return from Sweden he became Director of the
University of Parma. Among his works are Vacuum proscription,
Genoa, 1649 ; De terra machinio mota, Rome, 1668 ; Mechanicorum lib.
VIII., Lyons, 1684 ; De igne dissertationes physical, Venice, 1686, 1695 ;
Ilydrostaticce dissert., 1695 ; Opticce dissert., 1705. Lasswitz, Gesch. d.
Atomistik, 2, 490, says: " Im Einzelnen ebenfalls durchaus korpuskular
752 LEIBNITZ'S CRITIQUE OF LOCKE
sind die physikalischen Erklarungen des Jesuiten Paolo Casati . . . Aber
seine allgemeine Auffassung der Natur ist dabei vollstandig scholast-
isch."
PAGE 176, note 1. Add: Cf. Lasswitz, Gesch. d. Atomistik, 2, 421-428,
especially 423-424. Malebranche changed his views under the influence
of Huygens and Leibnitz. The Loix generates de la communication des
mouvements, Lasswitz says, was added as an Appendix to the later edi
tions of the Recherche de la verite.
PAGE 180, note 1. Add: Cf. § 13 of this chapter, infra, pp. 182-184,
New Essays, Bk. IV., chap. 6, ad Jin., infra, p. 462, note 1 ; also, Ger-
hardt, 7, 108-111 ; Erdmann, 669 ; also the fragment entitled De Libertate,
published by Foucher de Careil, Nouvelles Lettres et Opuscules inedits de
Leibniz, Paris, 1857, pp. 178-185. "Apart from the freedom of fact and
of right," says Schaarschmidt, t; Leibnitz distinguishes between ethical
freedom and free-will ( Willkur}. The former, ethical freedom, is the
power to follow the ethical insight in spite of opposing internal hin
drances, such as the passions. This concept also is clear and simple.
The difficulty proper lies hidden in the conception of free-will (der
Willkllr}, the liberum arbitrium, by which, as Leibnitz expresses him
self, is meant, 'that the strongest reasons or impressions which the
understanding presents to the will do not prevent the act of the will from
being contingent, and do not give it an absolute and, so to speak, meta
physical necessity.' " Leibnitz regards the action of the will as a motive
which inclines, but does not compel, — but at the same time he assumes,
Theodicee, Pt. I., § 52, a self-determination of the will over against which
the expression incline appears as a mere evasion. Cf. infra, p. 462, note
1. On Leibnitz's doctrine of the Will and Freedom, cf. G. Class, Die
metaphys.Voraussetzungen d. Leibnitzisch Determinismus, Tubingen, 1874,
pp. 9, 78 sq. ; F. Kirchner, Leibniz's Psychologic, Cothen, 1875, pp. 82 sq. ;
M. Penzler, Die Monadenlehre u. Hire Beziehnncj z. griech. Philos.,
Minden, 1878, p. 23 ; L. Braeutigam, Leibniz und Herbart liber die Frei-
hnt des menschl. Willens, Heidelberg, 1882, pp. 3-17, 28-39 ; M. Nour-
risson, La Philosophic de Leibniz, Paris, 1860, pp. 268-286 ; Kuno Fischer,
Gesch. d. n. Philos., Vol. 2 [Leibniz] pp. 512-533, 3d ed. Heidelberg,
1889. For a clear analysis and able, though brief, discussion of the vari
ous senses in which the " freedom of will " is used, and of " determinism,"
cf. Robinson, Principles and Practice of Morality, pp. 122-137.
PAGE 180, note 2. After " 1881," add : pp. 68 sq. The Greek text of
the passages referred to reads thus: 'RBiKa Xuto/idxcta, r, 4, 1112a 15: 77
yap TTpoa/petm /xera \6yov Kai diavotas. 5, 1112a 30 : pov\ev6fjie6a dt irfpi TUV
e0' JHJ.'IV irpaLKTuv. Cf., also, Sir Alexander Grant, The Ethics of Aristotle,
3d ed., London, 1874, Vol. 2, pp. 17, 19, 'H0. N«., III., chap. 2, § 17; chap.
3, § 7. Peter's translation follows the chapter and section numbering of
Grant's text. Cf., also, the following pasages from the so-called 'H0t/ca
Me7a\a — Magna Moralia — " which," Schaarschmidt says, " at least for
Leibnitz, was a genuine work of Aristotle," — though now regarded, ac-
ADDITIONS AND CORRECTIONS 753
cording to Zeller, as -a sketch compiled from both " the Nicomachean and
Eudemian ethics, "bat more especially from the Eudemian " (Philos. d.
Griech., II., 2 [Vol. 4J, 102, note 1 ; Outlines of the Hist, of Greek Philos.,
New York, 1880, p. 175): A, 16, 1188b25: eVei oe rb {KOIHTIOV ei> ovoe/j-ig.
opfj.r] effriv, \oiirov civ to; TO e/c oiavoias yiyv6/j.evov. 1188b 31 : o>s rov
&VTOS ev r$ diavo-rjdijvaL. 1188b 37 : evravda apa TO €Kov<riov iriirrei eis TO
diavoias. A, 17, 1189a 31 : et TO'LVVV i] Trpoaipeffis 6pe£is TIS fiovXevriKrj fj.erd
Biavoias, OVK f<m rb eKOV<riov irpoaipcrov. eK&vres yap iro\\d irpdrro/jLev irpb
rov diavoij0rjvai /cot pov\€v<ra<rdcu, olov Kadifrfj-ev /cat dvcffrdfieffa /cat ctXXa TroXXd
TotaOTO e/coJ'Tes /JL£V &vev de TOV diavofjdijvaiy r6 5e Kara. irpoaipe<riv ira.v ijv /j-crd
diavoias. OVK apa rb CKOIHTLOV irpoaiperov, dXXd TO irpoaiperbv eKovaiov • av n
yap Trpoaipu/J.f0a irpdrreiv /3ouXei»<rd^ei'ot, fKovres irpdrro/J-ev. With this last
passage, c/. 'H^. Nt/c., F, 4, llllb 6: 17 irpoaipetris STJ €Kov<riov ptv tpaiverai,
ov ravrbv 5^, dXX' tiri ir\eov rb CKOIXTLOV. 1112a 14 : €Kov<riov ^v STJ <paii>erai
[TJ frpoaipeffis^, TO 5' e/coi5<rioi> ov TTO.V Trpoaiperov. Ill3a 9 : oWcs 5e TOU irpoai-
perov ftov\evrov opeKrov r&v e0' rjfjuv, /cat i) irpoaipe<ri.s ai> etr) /3ouXeuTi/c7j 6/)e|ts
ruv 60' jjfjuv. The 'K0. Nt/c., r, 3, lllla 22, defines rb eKovo-cov, the vol
untary, — das Freiioillige, — thus: TO e/couo-toj/ 66^eiev av tlvai ov ij dpxy fv
OUTO; eiSoTt rd Kad' eKa<rra ev ofs TJ irpai;<.$. 'R6. Eu5^/xta, B, 8, 1224a 6 :
XetVcTat eV rip SiavovfJ.fv6v TTWS irpdrreiv elvat rb fKOVcriov. B, 9, 1225* 36 :
eVet de rovr' fX€l T^Xos, /cat ouTe rrj 6p£j-et ovre rrj Trpoacptcrei rb eKOVffiov wptff-
Tat, Xot7r6f 8rj bpiffaffdai rd Kara didvoiav. B, 10, 1226b 6: i] ydp irpoaipeffis
aipeffis fj.tv e<rriv, ovx aVXws 5^, dXX' ertpov irpb ertpov ' rovro 5£ oi>x olov
re avev ffKeif/ews /cat /SouX^s. 5to e/c 56^7;$ f3ov\evriKrjs ecrriv rj Trpoaipcffis. Cf.,
also, Zeller, Philos. d. Griech., 3d ed., II., 2 [Vol. 4], 587 sq.
On Aristotle's doctrine of the Will and Freedom, cf. 'H0. Nt/c., T. 1-8,
1109-1115; Grant, Ethics of Aristotle, 2, 5-32, and notes; also his Plan
of Book III., ibid., iii., iv., and Essay V., 1, 284 sq. ; Essay VII., 1, 376 sq. ;
J. A. Stewart, Notes on the Nicomachean Ethics of Aristotle, Oxford.
Clarendon Press, 1892, Vol. 1, pp. 224-230, 232-236, 240, 243-245, 250,
279 ; Vol. 2, pp. 16, 17, 379, 380 ; Trendelenburg, Histor. Beitrage z.
Philos., 2, 149 sq. ; Windelband-Tufts, Hist, of Philos., § 16, 2, pp. 191,
192.
<)u Leibnitz's relations and indebtedness to Aristotle, cf. I). Jacoby,
Dr. Leibnitii Studiis Aristotelicis, Berlin, 1867 ; D. Nolen, Quid Leib-
•mzins Aristoteli debuerit, Paris, 1875 : M. Penzler, Die Monadenlehre u.
i/it'f Beziehumj z. griech. Philosophie, Minden, 1878, p. 29.
PAGK 183, line 13 from bottom, "The best." Cf. New Essays, Bk,
TV., chap. 6, ad Jin., infra, p. 462, note 1.
PAGE 184, lines 7, 6 from bottom, "A freedom of equilibrium absolutely
imaginary and impracticable." Leibnitz argues against indeterminism
and equilibrium of will, cf. Gerhardt, 7, 109: " Lioertas indiffer entice est
impossibilis. Adeo ut ne in Deum quidein cadat, nam determinatus ille
est ad optimum efficiendurn. Et creaturse semper ex rationibus internis
externisque determinantur " (ib., 110, in French^; Erdmann, 669 (in
Latin). Cf. Robinson, Principles and Practice of Morality, p. 126.
LEIBNITZ'S CRITIQUE OF LOCKE
PAGE 185, line 20, "Vigor of Will." Of. Robinson, Principles and
Practice, of Morality , p. 138, where Virtue is denned as "the soul's or the
will's persistency of compliance, — its energy in complying with the moral
law, " — a definition perhaps suggested by that of Kant, quoted in the
foot-note : "the strength of the human will in the performance of duty."
PAGE 185, note 1. After "Erdmann," add: Janet.
PAGE 192, line 8, "Clearly felt." Schaarschmidt says: "Our feelings
can be very lively, while the ideas causing them may be obscure, con
fused, nay even senseless (let one think, for example, of religious fanati*
cism, of drunkenness, the aberrations of revenge, etc.) ; on the other hand,
our thoughts can be distinctly, i.e. from one another, indeed be distin
guishable, without being clearly, i.e. in their own content, conceived."
PAGE 192. note 2. Add: The passage from the Ethica referred to in
this note is found in Vol. 1, pp. 270 sq. of this edition. Cf. also the
Short Essay on God, etc., Korte Verhandeling van God, etc., Bk. II.,
chaps. 5 and 19, ed. Van Vloten and Land, 2, 310, 338 ; Schaarschmidt's
German trans., pp. 54, 84 .sg., in J. H. v. Kirchmann's Philos. Bibliothek,
Bd. 18, 2d ed., Berlin, 1874.
PAGE 193, line 6, " Francisco Borgia." General of the Jesuits, 1565-
1572.
PAGE 199, note 1. Add: The texts of Erdmann, Jacques, and Janet,
and the translation of Schaarschmidt end at "pleasure."
PAGE 203, note 2. The note should read as follows : Gerhardt reads :
" On venons au propos ; " the phrase is wanting in the texts of Erdmann,
Jacques, Janet, and in Schaarschmidt's translation.
PAGE 204. note 1. After "proposer," the note should read: wanting
in the texts of Erdmann, Jacques, Janet, and in Schaarschmidt's trans
lation.
PAGE 204, note 2. After " gauche," the note should read : wanting in
the texts of Erdmann, Jacques, Janet, and in Schaarschmidt's transla
tion. For the allusion, etc.
PAGE 205, note 1. After " Erdmann," add: Janet.
PAGE 205, note 2. After "Erdmann," add: Janet.
PAGE 206, line 12 from bottom, "Following the good." Leibnitz is a
forerunner of Kant in the expression here used that the chief end of
reason is practical. "In Kant's view," says Schaarschmidt, "theo
retical reason has only the negative significance of raising us above the
contemplation of nature and the sphere of experience to that position
where beyond the sensuous the practical principles, by means of a legis
lation derived from freedom, unconditionally determine the will." Cf.
also Leibnitz's definition in the same sense of " wisdom as the science of
ADDITIONS AND CORRECTIONS 755
happiness," Gerhardt, Leibniz, philos. Schrift., 7, 86; Erdmann, 671:
" Weisheit 1st nichts anders als die Wissenschaft der Gliickseeligkeit, so
uns nehmlich zur Gliickseeligkeit zu gelangen lehret."
PAGE 208, line 21, " Endure forever." Cf. Spinoza, Korte VerhandeUng
van God, Bk. II., chap. 26, ed. Vloteii and Land, 2, 359 ; Schaarschmidt's
trans. 105 : " Zo konnen wy 't met reden voor een groote ongerijmtheid
achten, 't geene veele, en die men anders voor groote god-geleerde acht,
zeggen ; namelijk, byaldien op de liefde Gods geen eeuwig leeven en
kwarn te volgen, zy als dan haar zelfs best zouden zoeken ; even als of zy
iets dat beter was, als God, zouden uytvinderi. Dit is alzo onnozel als of
een vis wonde zeggen (voor welke doch buyten het water geen leven is) :
by aldien my op dit leven in het water geen eeuwig leven en zoude
komen te volgen, zo wil ik uyt het water na het land toe ; ja niaar wat
konnen ons die God niet en kennen dog anders zeggen?" i.e. "Thus
we can rightly pronounce exceedingly absurd the statement which many,
whom we otherwise deem great theologians, make ; namely, that if eternal
life did not follow from the love of God, then man should seek his own
best good, as though man thereby could find something better than God.
This were just as foolish as if a fish [for whom out of the water there is
no life] should say, if for me after this life in the water no eternal life
follows, I will go out of the water on to the land. What else, how
ever, can they who do not know God say to us ? " Schaarschmidt thinks
that Leibnitz's accord with Spinoza was perhaps mediated by the Stoic
doctrine.
PAGE 208, line 25, " Absolutely indispensable." Cf. infra, p. 261, note
"2. Leibnitz, while admitting the truth of the Aristotelian and Stoic view,
nevertheless contests that in this life we cannot always demonstrate the
identity of the virtuous and useful, and supports the life of duty and
overcomes the dualism between duty and pleasure through the '-thought
of God and immortality." Kant grounded rational belief in immortality
upon this very dualism.
PAGE 210. note 1. After "Erdmann" add: Janet.
PAGE 210, note 2. Add: Eraser, Locke's Essay, 1, 358, reads: § 66.
His edition gives full account of all the various readings and changes in
the various editions of Locke's Essay, including those in the translation
of Coste. It is in all respects the best edition of the Essay yet issued,
and the thanks of all students of philosophy are most heartily rendered
to Prof. Eraser for his splendid work.
PAGE 211, note 1. Add : 3d ed., enlarged, 2 vols., 8vo, A. & C. Black,
Edinburgh, 1893.
PAGE 212, line 25, "Turn them aside from it." Cf. New Essays, Bk.
II.. chap. 27, § 36, Th. ; ante. pp. 194 sq., § 53, Th., 207. Perfectibility is
Leibnitz's ethical norm, and the "luminous pleasures" are those which
assist us in our efforts to attain this perfection, because they spring out
756 LEIBNITZ'S CRITIQUE OF LOCKE
of the need of, and therefore also out of the idea, though obscure, of the
true good.
PAGE 213, line 12. " Greatness of the consequent.1' Janet, CSuvres
philos. de Leibniz, 1, 185, note 1, says: " The greatness of the conse
quence, i.e. the greater or less probability that the foreseen good or evil
will occur ; the greatness of the consequent, i.e. the greater or less good
or evil which the outcome must bring."
PAGE 213, note 1. After " Erdmann," add : Janet.
PAGE 214, note 1, line 1. After " 70a 3," add : TO fj.ev ei'/cos eon-i Tr/oorao-ts
e vdo£os ' o yap us etri TO iro\v icraffiv OVTU yivo/j-evov ?/ pr) yivoftevov 77 ov r/ IJLTJ &v,
TOUT' eo-Tiv eiK&s, i.e. "The probable," etc. And in line 5, after " 1357a 34,"
add : rb ptv yap et/coj e<?Tiv is CTT! TO TTO\I) yi.v6fj.evov, i.e. " For the proba
ble," etc.
PAGE 217, line 2 from bottom, "World." "Because," as Schaar-
schmidt says, " mathematics as the science of magnitude is applicable
only to sensible things."
PAGE 218, lines 18, 19, " The term thought in the same general way."
" We exercise an inner activity," says Schaarschrnidt, " either so that we
produce perception-(phantasie-) images or (formulated — sprachgeformte)
thought-images. The lower situated entelechies do the former, of the
latter minds only are capable. We can, continues Leibnitz, in case of
necessity designate both of these activities as thought. To-day we [the
Germans] use ' Yorstellen ' as the most general expression to indicate
the inner activity."
PAGE 218, note 1. Add : Eraser's Locke's Es*ay, 1, 371, line 3.
PAGE 219, line 26, "Comes from thought.]" Schaarschrnidt says in
his note to this passage : "These weighty expressions are the pure result
of the fundamental thought, that every substance acts from an inner
spontaneity. Passion thus has for the spirit only the significance of a
confused and therefore imperfect activity, whose most pregnant expres
sion for the subject is pain ; for bodies, however, passion means an
imparted or mediated activity, in connection with which it is to be con
sidered that, since bodies are mere phenomena, their changes are also
only phenomenal, whose grounds must always be sought in the spontane
ous forces of simple substances (out of whose joint-existence — Zusam-
mensein — our confused thought forms the corporeal mass)." Cf. New
Essays, Bk. II., chap. 8, ante, p. 131, note 1. Schaarschmidt adds:
"Activity in the absolute sense, however, is the transition to greater
perfection and thence also accompanied with pleasure."
PAGE 219, note 1. After " Jacques," add : and Janet.
PAGE 220, line 2 from bottom, "Complete separation." Schaarschmidt
says in his note to the text at this point, "Separation arises from the
Aristotelian concept xw/n<r,u6s. Xwoifeif is the separation or loosing of the
ADDITIONS AND CORRECTIONS 757
purely spiritual from the material. After Descartes had again renewed
the ancient Platonic-Aristotelian Dualism in another way, Spinoza and
Leibnitz, each in his own way, again set up a monism, which the realistic
tendency of Locke in another way and towards another goal also endeav
ored to attain."
PAGK 220, note 1, line 2. After " Erdrnann," add : Janet.
PAGK 222, line 10 from bottom, "Old word." That is " chevauchier,"
"chevalchier," "chevaucher," "• chevalcher," " cevaucier," all these dif
ferent forms occurring in the old writers. For examples, cf. Littre", who
gives the Provengal "cavaloar," "cavalguar," Italian "cavalcare," all
derived from the Low-Latin " caballicare." " Chevaucher," says Littre,
is reserved for elevated style and especially for narrations regarding the
Middle Age ; "aller a cheval" is the common and daily form of speech.
PAGF. 222, line 2 from bottom, "Seen." Schaarschmidt says: "That
Locke here makes the formation of the mixed or compound modes pro
ceed from wider experience, to which he certainly adds 'invention' —
from a purpose — Leibnitz not only allows in a noteworthy fashion, but
he also adds thereto as a further source the activity of the fancy. Locke
undoubtedly understands by mixed modes something wholly different
from that which is formed by means of dreams and fancies ; namely,
abstractions from given compound relations, which, according to the
measure of our interest, or at least of our attention, are formed and
linguistically fixed."
PAGI: 223, note 1. Add : For Leibnitz on Mademoiselle de Scudery, in
the " Monatlicher Auszug aus allerhand neu herausgegeben, niitzlichen
und artigen Buchern," Dec., 1700, pp. 909, 910, and Dec., 1701, IV., cf.
Guhrauer, Leibnitz's Deutsche Schriften, 2, 414-420. Cf., also, Foucher
de Careil, Lettre.s et opuscule* inedits de Leibniz, Paris, 1854, pp. 254-
2(50 : F. de Careil, (Euvres de Leibniz, 2d ed., Paris, 1869, 2, 515-517.
PALI: 224, line 23, "Called causes in the schools." Cf. Appendix,
infra, pp. 637, 672 s</., 699 sq., for Leibnitz's further exposition of the
doctrine here set forth. In this place, "without allowing himself to
enter upon a critique of Locke's exposition of the term primal cause,
Leibnitz," says Schaarschmidt, "contents himself with ascribing to it a
double signification, one of which goes back to the Aristotelian termi
nology ; the other indicates the end. At the same time, however, he
mentions the fact that the primal cause may also be understood as the
material ground of a thing. Critical investigation of this important con
ception first begins with Hume."
PAGE 227, line 11, "Promoter." Cheruel, Dictionnaire des Institu
tions Fran^aises, sub voc., says : " Promoteur" : " Eccle"siastique charge
du ministere public dans les officialites (voy. ce mot) [in that article it
is explained that officialite = the court of a bishop or archbishop], dans
les assemblies du clerge, dans les chambres superieurs ecclesiastiques, en
un mot dans tons les tribunaux ecclesiastiques. Les fonctions des
758 LEIBNITZ'S CRITIQUE OF LOCKE
moteurs consistaient surtout & maintenir les droits, liberty's et immunit&s
de 1'Eglise ; a veiller & 1'observation de la discipline ecclesiastique et a
poursuivre les crimes et debits qui etaient de la competence des juges de
1'Kglise. II y avail quelquefois dans les officialite's un vice-promoteur ; il
e"tait, comme le promoteur, nomme par 1'eveque."
In short, the promoteur was a sort of ecclesiastical district attorney,
and he is here on the opposite side of the case from the young lawyer.
When he calls the lawyer "doctor juris," the latter objects that he ought
to call him "doctor juris utriusque," i.e., doctor of both civil and canon
law, or in our phrase, doctor of laws, LL.D. To which the promoteur
replies sarcastically.
PAGE 227, note 2, line 3. After "Eucken," insert: Gesch. und Kritik
der Grundbe.yriffe der Gegenwart, Leipzig, 1878, pp. 69-78 (Leibnitz, p.
70) ; Die Grundbegriffe der Gegenwart historisch und kritisch entivickelt,
2te, vollig umgearbeitete Auflage, Leipzig, 1893, pp. 98-102 (Leibnitz,
p. 98), but not so fully as in the 1st ed., the author stating in the Preface,
that "the historical statements are strictly limited to that which appears
immediately requisite to the understanding of the present time." Eng.
trans, of 1st ed. , The Fundamental Concepts, etc. At end of note, add :
Schaarschmidt states Leibnitz's view thus : "Knowledge a priori means
with Leibnitz, who with his predecessors in this matter attached himself
to the Aristotelian conception of the irpbrepov ry <pucrci, knowledge from
the cause, and, accordingly, knowledge a posteriori means with him
knowledge from the working or result, and therefore from external ex
perience resting upon the phenomenon of things." Kant's usage differs
from that of Leibnitz. A priori knowledge is for Kant that which pro
ceeds from pure reason and not from experience ; while a posteriori
knowledge comes only from external experience, not "from result and
working in general." Cf., also, J. II. von Kirchmann's Erlauterung,
No. 25, to the Theodicee, Bk. I., § 44 ; p. 34 of his Erlauterungen zur
Theodicee v. Leibniz, Leipzig, 1879.
PAGE 228, note 2. Cf. infra, pp. 399, note 3, 551, note 4.
PAGE 229, note 2, line 1. After "II. and VI.," add : ed. Cousin, 1,
240 sq., 322 sq.
PAGE 230, note 1. After "Dioptrica, IV., 1 sr/.," add: ed. Cousin, 5,
34 sq. ; after liPassiones Animce, I., 31 .<?</.," add: ed. Cousin, 4, 63 sq. •
after "Frm. Philos., IV., 189, 196. 197," add: ed. Cousin, 3, 500, 507,
509.
PAGE 230, note 1. Add: Cf., also, Cousin, (Eiccrvs de Descartes, 8,
200, where Descartes, in a letter (dated by the annotator 1640 — the
letter in Bk. II. , Xo. 3(5, in ed. of 1666) to Meissonier, "m&lecin de
Lyon," says: "Mon opinion est que cette glande " ["la petite glande
nominee conarion'1'1^ "est le principal sie"ge de I'ame, et le lieu oil se font
toutes nos pensees. La raison qui me donne cette creance est que je ne
trouve aucune partie en tout le cerveau, excepte celle-l<i seule, qui ne soit
ADDITIONS AND CORRECTIONS 759
double," etc. In a letter to Mersenne, dated by the annotator April 1,
1640, Cousin, (Euvres de Descartes, 8, 215 sg. [ed. of 1666, Bk. II., Letter
No. 38], Descartes makes substantially the same statement and gives the
same reasons therefor, and adds: " Mais je crois que c'est toute le reste
du cerveau qui sert le plus a la memoire," etc.
PAGE 233, line 4 from bottom, " The union of the soul and the body."
Leibnitz was undoubtedly satisfied that his Pre-established Harmony
satisfactorily explained the "union of the soul and the body," and for
those who accept his philosophy it does. But those who look for another
explanation, for example, in a real reciprocal action between the soul and
certain substances of the body, find in Leibnitz's semi-spiritualistic inter
pretation of matter a clue or suggestion thereto.
PAGE 235, end of chap. 24, "Comprising substances." Leibnitz, ac
cording to Schaarschmidt, means to say that, strictly understood, the
collective ideas are not signs of substances, rather, indeed, are the single
objects themselves substances, as, for example, the army, the herd, con
sist of substances. Yet the collective ideas serve to a certain extent indi
rectly to indicate substances. Leibnitz adds this concession here because
in his system of monads he departs very widely from the customary con
ception of substance, and yet may not lose all touch with the linguistic
usage.
PAGE 235, line 6, 5 from bottom, "Essence of reason." That is, ens
r((twnis, which actuality reaches only so far as it is a thought-image.
PAGE 235, line 3 from bottom, "Comes from the supreme reason."
" Relations, so Leibnitz will have us understand the matter," says Schaar
schmidt, "are in the first place products of our thought, for they are
neither the expression of substances, nor of the determinations (Attribute,
Modi) inhering in them, but the expression of our subjective conception
of the relation of things to one another. But this human conception,
although also subjective, is yet again grounded in the nature of things, in
particular in the nature of the mind, and to this extent springs out of its
own constitution, like the eternal truths. And the constitution of the
mind, as the 'mirror of the universe,' corresponds again to reality in
virtue of the pre-established harmony. The thoroughgoing parallelism of
the inner with the outer occurrence gives consequently to the relations,
according to Leibnitz, a certain real meaning."
PAGE 239, note 1, line 4. Instead of "Leben," read : Fine Biographic.
PAGE 241 , note 1. Add : Corpus Juris Civilis, 6th stereotyped ed., Vol. 1,
p. 650, a ; Digesta, ed. Mommsen, Berlin, Weidmann, 1803. Schaarschmidt
says it is "a definition springing from Stoicism," and compares Gop-
pert. Ueber einheitliche, zitsammenyesetzte und Gesammtsachen nach r'dm.
Jtrclit. pp. 7 .sv?., 20 sg., Halle, 1871.
PAGE 242, line 4, " Soul." Leibnitz is right in placing the identity of
man in the soul and its conservation, instead of in the "well-organized
760 LEIBNITZ'S CRITIQUE OF LOCKE
body," as Locke does. The relative unity of the bodily organism results
from the absolute unity of the soul.
PAGE 245, note 1. Cf. Eraser, Locke's Essay, 1, 448, note 3. This sec
tion is numbered § 11 in Eraser's ed.
PAGE 245, note 2. After " Erdmann," add : Janet.
PAGE 246, note 1. After " Erdmann," add : Janet.
PAGE 247, lines 7-9. '•''The. self constitutes identity real and physical/'
etc. This sentence contains the gist of the whole discussion. "The self"1
or the ego which "constitutes identity real and physical" is "the pre
supposition of that consciousness of the subject of itself to which the
conviction of its own reality attaches." Consciousness itself is an active
though involuntary modification or state of this self or ego. "The phe
nomenon of self" is the ego's actual consciousness of itself, as the subject
of all its inner experience, and as the constant accompaniment of the
same. The self is accordingly by Leibnitz regarded as a real entity, a
substance, constituting in itself "real and physical identity" which is
recognized as "personal " in consciousness. But it must be remembered
that for Leibnitz substance is dynamic, its essence is action, and its real
identity consists in the continuity and connection of its activity. When
this activity becomes distinctly conscious or is brought into distinct con
sciousness, it constitutes moral and personal identity.
PAGE •249. note 1. Add : Janet reads : "etant."
PAGE 250, note 1. Add : (Jf.t also, The Immortality of the Soul, Bk. II.,
chaps. 13, 14; Philos. Writings, ed. in 1 vol., London, 1662, pp. 116-121
(each treatise paged separately in this ed.).
PAGE 251, lines 12, 13, " Indifferent to every sort of matter." Janet,
(Euvres philos. de Leibniz, 1, 224, in his note to this passage, says :
•• Aristotle believed also that the soul is not indifferent to every kind of
matter, and avails himself of the fact to combat the doctrine of metemp
sychosis." Cf. Ilept ^vxrjs* Bk. I., chap. 5, Berlin Academy ed., 409a
31-41 lb 30 ; ed. E. Wallace, Cambridge, 1882, pp. 44-57.
PAGE 251, note 1. After "Gerhardt," add: Janet.
PAGE 251, note 2. After " Erdmann," add: Janet.
PAGE 252, line 6 from bottom, "Two persons." On double and alter
nate personality, cf. James, Psychology, 1, 379-392.
PAGE 252, note 1. Add: Eraser's Locke's Essay, 1, 460, line 8.
PAGE 252, note 2. Add: Eraser's Locke's Essay, 1, 461, line 6.
" Sober" = " sane."
PAGE 254, note 1. After " Erdmann," add : Janet.
PAGE 254, note 2. After "Erdmann," add: Janet.
ADDITIONS AND CORRECTIONS 701
PAGE 256, lines 17-20. "For since there is an individual diversity,"
etc. Cf. New Essays, Bk. II., chap. 27, § 3, Th., ante, p. 239, and note 1 ;
Bk. III., chap. 6, § 8, Th., infra, pp. 331, and 332, note 1. All true or
actual difference is individual difference, consisting in some internal dif
ferentiating principle specifying the existence in this or that definite way,
even though it first reveals itself only in " the course of time." With this
thought is closely connected that of identity, on which cf. ante, p. 247,
and note to lines 7-9, ante, p. 700.
PAGE 257, note 1. After "Erdmann,'1 add: Janet.
PAGE 258, line 10, " Magnitude which I call imperfect.''1 An imperfect
magnitude is one which, because of its infinite minuteness, admits of no
measurement.
PAGE 259, note 1. After "Erdmann," add: Janet.
PAGE 259, note 3. After " Erdmann," add : Janet,
PAGE 201, note 1. Add: Punjer, Gesch. d. christlich. Reliyiomphi-
losophie, Braunschweig, 1880, 1, 123, Eng. trans., Edinburgh, 1887, 1,
105, in his account of the controversy of Vedelius and Joh. Musseus (cf.
ante, p. 587, notes 1,2), gives, from Musseus, another use of the term.
Punjer says : " 1st aber die philosophische Pramisse allgemein, die theo-
logische partikular, dann muss sorgfaltig untersucht werden, ob die
betreffenden philosophischen Principien nothwendig und allgemein gel-
ten (absolute et simpliciter necessaria) oder nur fiir ein besonderes
(Jebiet, bedingungsweise (secundum quid et physicey ; i.e. "But if the
philosophical premiss is universal and the theological premiss is particular,
then it must be carefully examined whether the philosophical principle in
question is necessarily and universally valid (absolute et simpliciter neces
saria), or applies only to a particular sphere and conditionally (secundum
quid etphysice)." [Italics are mine. — TR.]
PAGE 201, note 2. Add : Cf. New Essays, Bk. II., chap. 21, § 55, ante,
p. 208, and note to p. 208, line 25, ante, p. 755.
PAGE 202, note 1. Add: Leibnitz, Observationes de Principio Juris,
§ 13 (Dutens, Leibnit. op. om., 4, Pt. III., 273), says: "Deum esse omnis
naturalis juris auctorem (quod ait § 41) verissimum est, at non voluntate,
sed ipsa essentia sua, qua ratione etiam auctor est veritatis," etc.
PAGE 202, note 2. Add: Cf, also, Dr. Robinson's Lecture, "Moral
Law in its relations to Physical Science and to Popular Religion," in
Boston Monday Lectures — Christ and Modern Thought — 1880-1881,
pp. 31-59.
PAGE 203, note 1. Add: Teubner, Leipzig, 1805. Vopiscus says of
Bonosus : " Bibit, quantum hominum nemo. De hoc Aurelianus saepe
dicebat : 'Non ut vivat natus est, sed ut bibat,' quern quidem diu in
honore habuit causa militire. Nam siquando legati barbarorum unde-
cumque gentium venissent ipsi propinabantur, ut eos inebriaret atque ab
762 LEIBNITZ'S CRITIQUE OF LOCKE
his per vinum cuncta cognosceret. Ipse quantumlibet bibisset, semper
securus et sobrius et, ut Onesiinus dicit, scriptor vitse Probi, adhuc in
vino prudentior."
The reference in the next line, also taken from Vopiscus, ibid., is to
Proculus, and not Bonosus, and the text should be corrected accordingly.
PAGE 264, line 10, " Depends upon truth." I.e., as Schaarschmidt
says, '-upon the ever-equal reality of the ethical world-order."
PAGE 267, note 1. After " Erdmann," add: Janet.
PAGE 270, note 1. After "Erdinann," add: Janet.
PAGE 273, note 1. After "Erdinann," add: Janet.
PAGE 273 note 2. After " Erdinann," add: Janet.
PAGE 274, note 1. After "Erdinann," add: Janet. After "§15,"
add : So also Eraser's Locke's Essay, 1, 493.
PAGE 274, note 3. Add : Eraser's Locke's Essay, 1, 494, reads § 16.
PAGE 275, note 1. After " Erdinann," add : Janet. Eraser's Zone's
Essay, I, 494, reads: "betwixt the 100,000th and the 1,000,000th part
of it."
PAGE 276, note 1. Add : Of. Gerhardt, Leibniz, philos. Schrift., 3, 225,
where Leibnitz says: " II est encor a propos de considerer qu'il y a deux
abus considerables dans les definitions, qu'on pent commettre en voulant
former des ide"es : Pun est ce que 1' excellent Jungius (<\f. Appendix, infra,
p. 636, note 1), appelloit obreption, 1'autre est ce que j'appelle chimerisme,
par exemple si quelqu'un raisonnoit ainsi : il m'est pennis de combiner les
idees, et de donner un nom a ce qui en resulte ; prenons done 1'idee d'une
substance ou il n'y ait rien que de 1'etendue et appellons cela corps, done
les corps qui sont dans la nature n'ont rien que de 1'etendue, il y auroit a
la fois ces deux fautes dans ce raisonnement. L'obrrption y seroit en ce
qu'ayant donne" au mot : corps, la definition qui bon me semble (ce qui
est en quelque fagon arbitraire), je veux par apres 1'appliquer a ce que
d'autres hommes appellent corps. C'est comme si dans la Geometric
quelqu'un donnoit a ce mot : ovale, la definition que d'autres Geometres
donnent a 1' Ellipse, et vouloit prouver par apres que les ovales de M. des
Cartes sont des sections du cone. Le chimerisine est icy d'avoir fait une
combinaison impossible, car on n'accorde point qu'il est possible qu'il y
ait une substance qui n'ait que de 1'etendue. Je sgais que ces Messieurs
veulent se justifier de 1' obreption, en disant qu'on ne sgauroit concevoir
autre chose dans les corps qui sont dans la nature, que ce qu'ils ont mis
dans leur definition ; mais en cela ils commettent une fausse supposition,
ou bien ils confondent concevoir et imaginer ; car il est bien vray qu'on ne
S9auroit imaginer que ce qui est etendu, mais ils reconnoissent eux memes
ailleurs qu'on congoit des choses qui ne sont pas imaginables. Ouy,
diront ils, mais ce n'est que la pensee qu'on ne peut point imaginer. Je
reponds, qu'en cela ils font encor une autre fausse supposition, en pre-
ADDITIONS AND CORRECTIONS 763
tendant que rien ne s§auroit estre conga que pense~e et e"tendue, oublians
qu'ils parlent souvent eux memes de la force qui n'est pourtant ny Pun
ny 1'autre, outre qu'ils n'ont point prouve' qu'il n'y a rien de possible que
ce que nous concevons."
PAGE 277, line 8, "Capable of existing together." Leibnitz, in argu
ing against Locke's view of the passivity of the mind in relation to its
"simple ideas" and its activity in their combination into "complex
ideas," affirms that the mind "is active in reference to simple ideas,"
that the relations are objectively significant and valid through the deter
mination of the "supreme intelligence," that the mixed modes " may be
real accidents," which do not become merely subjective from the fact
that we perceive them by thought. According to Leibnitz, everything
really possible is in a certain sense an actual object of intelligence : to
the divine intelligence an actual, to the human intelligence a universally
possible object. The external existence of this thought-object really adds
nothing to the being of this object, and alters nothing in the relation of
the thought to it. <?/., also, New Essays, Bk. II., chap. 12, § 3, Ph.,
ante, p. 147, and note to line 2 from bottom, "modes," ante, p. 748.
PACE 277, note 1. Add: Eraser's Locke's Essay, 1, 500. In § 1, Locke
has " Fantastical or chimerical," Eraser's ed., 1, 497; Bonn's ed., 1, 508.
PAGE 277, note 2, line 1. After " 345a 25," add: oi 5£ irepi 'Kva&ybpav
Kai ^.rj^oKpiTov 0cDs fivat. rb yd\a \£yov<riv ctcrrpwp rwOiv • TOV yap rjXiov UTTO
T7)i> yr}v c£>ep6iJ.evov of/x opdv evict rCjv affTpwv.
PAGE 281, note 2. Add: The Greek text of the passages referred to
in the note is as follows : Hepl ^u%^s F, 6, 430a 26-30 : 17 /j.tv o&v T&V
ddiaiperuv vo^cris ev TOVTOLS, irepi a. OUK eVri TO i/'eCSos • ev oh d£ Kai TO i/'eOSos
Kai TO dXtjdes, (rvvdecris TLS ijdrj voT}p.a.Twv wvirep ev OVTWV, nadairep 'EyUTreSo/cX^s
€<f>r] " rj 7roAAa)i> /j.ev Kopcrai dvavx^ves e/SXacrrT/o-ar," eVeiTa (rvvTiOeo'dai. Trj (f)i\ia.
Hepl 'Ep/UT/i/eias I., 16a 12: (rrj/j.eioi> 5' ecrrt Tovde" /cat yap 6 Tpaye\a<pos
<r-r]IJ.aii>ei ^v TL, oviru de d\f]6es T? ^eOSos, edv fj.r) TO elvai TJ fj.rj elvai TrpoffTedrj,
TI aVXcDs T? KaTa xp°vov- Cf., also, New Essays, Bk. III., chap. 3, infra,
pp. -310-318, and the notes, especially pp. 310, note 2, 317, note 3.
PAGE 281, line 17, "Possibility." Schaarschmidt states that Christian
Wolf placed this definition of truth here given by Leibnitz at the head of
his collected science. According to Wolf, Log. Disc, prwlectt., philoso
phy is the science of the possible so far as it can be. Ueberweg, Hist, of
Philos., Eng. trans, by Morris, New York, 1871, Vol. 1, p. 4, gives it,
Philos. Rationalis. Disc. Prcelim., §29: " philosophia est scientia possi-
biliuin, quatenus esse possunt."
PAGE 281, note 1. After "Essays," add : Bk. III., chap. 3, § 15, Th.,
infra, pp. 315 sq., especially p. 317, note 3 ; after " chap. 5," add : ad fin.,
infra, p. 452, and note 1.
PAGE 282, note 1. After "Erdmann," add: Janet.
PAGE 282, note 2. After "Erdmann," add : Janet.
764 LEIBNITZ'S CRITIQUE OF LOCKE
PAGE 283, line 17, " Ottavio Pisani." An Italian jurist, who published
in Italian his Lycurgus sen leges promptam justitiam promoventes ; trans
lated into German, and published, Sulzbach, 1666, 12mo. Leibnitz men
tions him in his Bedenken welchergestalt den Mdngeln des Justiz-Wesens
IN TiiEORiA abzuhelfen, cf. Guhrauer, Leibnitz* s'deutsche Schrift., 1, 257,
also Beilagen, ibid., 42 ; Dutens, Leibnit. op. om., 4, Pt. 3, 230-234 (Latin
trans, of the same, regarding which, cf. Guhrauer, op. cit., 1, 41 sq. — On
p. 41, op. eft., line 9 from bottom, "220-24" should read: 230-234, as
above cited, the present reading being a typographical error).
PAGE 283, note 1. After " Erdmann," add : Janet.
PAGE 284, line 17, " Inclinations." Schaarschmidt says that u in these
remarks lies the germ of the recognition of the law of association, which "
Johann Gebhard Ehrenreich Christian Maass, 1766-1823, Professor of
Philosophy at Halle University, "further elaborated in his Versuch liber
die Einbildungskraft, Halle and Leipzig, 1797 ; afterwards J. F. Fries,
1773-1843, in his New Kritik der Vernunft, 2d ed., 1828-1831, p. 148 »<?.,
and which finally J. F. Herbart, 1776-1841, and his school have attempted
more closely to investigate and establish." F. II. Bradley, The Princi
ples of Logic, pp. 279, 297, 312, 313, refers to a portion of Maass' discus
sion. Cf., also, Hamilton's Reid, Notes I)** and I)***, 2, 882-917, espe
cially 890, 899, 913 sq. Maass followed Wolff's Psych. Emp., Frankfort
and Leipzig, 1732, ed. Nova, 1738 ; but he may also have been influenced
somewhat by Leibnitz, as the New Essays were published in 1765 by
Kaspe, and therefore accessible for nearly thirty years before his own
work appeared.
PAGE 284, note 1. After " Erdmann," add : .Janet.
PAGE 284, note 2. After "Erdmann," add: Janet.
PAGE 284, note 3. After " Erdmann," add : Janet.
PACE 284, note 4. After " Erdmann," add : Janet.
PAGE 286, note 1. Add: Recently Mr. R. L. Garner has been investi
gating the language of monkeys, with the aid of the phonograph, and
published an account of his investigations in an interesting book entitled
The Speech of Monkeys, New York, Chas. L. Webster & Co., 1892. An
unfavorable notice of the book appeared in "The Nation," October 6,
1892, p. 267 b, the gist of which appears in the following sentence : " As
a scientific record of original discoveries, it has little value."
PAGE 288, note 1. Add : Cf. New Essays, Bk. III., chap. 3, § 5, Th.,
infra, pp. 307, 308. Also, Hamilton, Metaphysics, Lect. XXXVI. , pp.
492 sq., Boston, 1875.
PAGE 297, line 11, " Hypothesis," etc. Leibnitz's hypothesis has been
wholly verified by modern philology.
PAGE 297, note 1. Add: For an interesting account of Leibnitz's
services to comparative philology, cf. Max Miiller, Lects. on the Science
ADDITIONS AND CORRECTIONS 765
of Language, 2d ed., London, 1862, Lect. 4, pp. 131-135 ; New York,
Chas. Scribner, 1862, pp. 135-139. Cf., also, Guhrauer, Leibnitz, Eine
Biographie, 2, 126 sq. ; Foucher de Careil, (Euvres de Leibniz. 7, 519 sq.,
a rough draft of a memorial of Leibnitz concerning the study of lan
guages ... in the Russian Empire.
PAGE 298, note 1, line 3 from end. After "p. 409," insert: "Lites de
Boehmianis sententiis inanes esse censeo, et Boekmium nee sibi, nedum
aliis intellectum," i.e. etc.
PAGE 300, note 3. After " Erdmann," add : Janet.
PAGE 300, note 4. After " Erdmann," add : Janet.
PAGE 300, note 5. After " Erdinann," add : Janet.
PAGE 304, note 1, line 8. After " Dutens, op. cit., Vols.," add: 4, Pt.
II., p. 56: Ab insigni apud Bremenses Theologo Gerhardo Meiero, qui
(ut hoc obiter dicam) hortatu meo praeclarum opus aggressus est Glossarii
Saxonici titulo, in quo origines Germariicarum vocum multas eruet illus-
trabitque, nee pauca non pervulgata proferet in lucem." At end of note,
add: Janet, (Euvres philos. de Leibniz, 1, 274, note 3, gives the dates of
Meier's birth and death, 1646-1680, and titles of his "principal philo
sophical works" : Compendium logiccv, divina? ; Aranearum telas divines,
existent ice testes ; De dubitatione sceptica et cartesiana.
PAGE 304, note 2. Add : The date of Soli liter's death being 1705, and
the mention of the same in the text as having "just" occurred, is evi
dence that Leibnitz at least briefly touched up this part of the A>w
Essays as late as 1 705.
PAGE 308, line 10 from bottom. Read: Greathead, instead of -'large
Iwad ;" and line 8 from bottom, read : great, instead of "large."
PAGE 308, line 3 from bottom. After "wormwood," insert: (absin
thium).
PAGE 313, line 8, "Living rational being." Cf. Trendelenburg, Histor.
Bcitr. z. Philos., 3, 53, 54.
PAGE 316, note 1. After "(Bohn's ed.)," add : Eraser's Locke's Essay,
2, 28.
PAGE 317, note 1. Add : cf. Xew Essays, Bk. IV., chap. 4, § 5. Th..
infra, p. 445, note 1.
PAGE 317, note 2. Add : Cf., also, Xew Essays, Bk. II., chap. 21, § 3.
Th., ante, p. 175, and note to p. 175, line 18, ante, p. 751.
PAGE 317, note 3. Add: Cf., also, Prantl, (lesch. d. Logik, Bd. 1,
p. 516, note 33, where he refers to Cicero, Off., I., 2, 7 ; Fin., II., 2, 5 ;
D. orat,. I., 42, 189 : "est enim definitio earum rerum, quae sunt eius rei
proprise qnam definire volumus, brevis et circumscripta quaedam explica-
766 LEIBNITZ'S CRITIQUE OF LOCKE
tio"; II., 39, 164; III., 29, 113; Oral., 33, 166; Top. 5, 26; Quint.,
Inst.. VII., 3, 10.
PAGE 318, note 1. Add : Eraser's Locke's Essay, 2, 29.
PAGE 319, note 2. Add : Erdmaun, 443-445.
VAGE 321, note 4. After "chap. 9, ad med.," add: " ' How can that
he ? ' cried Don Quixote ; ' didst thou not tell me that thou sawest her
winnowing wheat? ' ' Take no heed of that, sir,' replied the squire ; ' for
* he fact is, her message, and the sight of her too, were both by hearsay,
and I can no more tell who the lady Dulcinea is than I can buffet the
moon.' '
PAGE 322, note 1. Add : Aldrich, Artis loyiccv rudimenta, ed. II. L.
Ivlansel, 3d ed., Oxford, 1856, pp. 30, 31 (diagram on p. 31).
PAGE 323, note 1, line 3. After " Erdmann," add : Janet.
PAGE 324, note 2. Add : Ilypoth. phys. nova, § 57 ; Gerhardt, 4, 208.
fjf, also, New Essays, note to p. 47, lines 18, 19, ante, p. 726.
PAGE 326, note 1. Add: Cf. note to p. 43, line 14, ante, p. 724.
''Leibnitz," says Schaarschmidt, "makes here a weighty remark. AH
demonstration appeals only to the (real) possible and to that which in a
\ogical way inferred from the same is so far thought-wise necessary ;
reality or the actual, on the other hand, can be known only historically
or empirically, not, however, philosophically."
PAGE 326, note 2. Add: Janet, (Euvres philos. de Leibniz, 1, 293,
agrees with the reading of Jacques.
PAGE 329, note 1, line 2. After " 1888," add : Paris Academy ed., by
C. M. Galisset, 7th ed., 1862, p. 140 ; Corpus Juris Civilis, Berlin, \Veid-
marin, 1893 (Inst. of Justinian, ed. by Paul Krueger), Vol. 1, p. 13 b;
line 3, after " 1890," add: Collectio Librorum Juris Ante Justin iani, ed.
Krueger, Mommsen, and Studemund, Vol. 1, pp. 50, 51, 3d ed., Berlin.
Weidmann, 1891; line 4, after "1870," add: Corpus Juris Civilis
(Digest, ed. by Mommsen, and paged separately), Vol. 1, p. 112. At
end of note, add : Rudolph Sohm, Institutes of Roman Law, trans, from
4th German ed., by Jas. Cranford Ledlie, Oxford, Clarendon Press, 1892,
pp. 258-268.
PAGE 332, note 1. Add : For Hegel's interpretation of Leibnitz's prin
ciple of individuation, — principium individuationis, — (cf. New Essays.
ante, p. 239, note 1) cf. Wallace, The Logic of Hegel. 2d ed., Oxford.
Clarendon Press, 1892, pp. 217, 218.
PAGE 333, note 1. Add: Fraser's Locke's Essay, 2, 68.
PAGE 334, note 1. Add: On the natural order in the vegetable king
dom, Schaarschmidt cites J. H. Burckhardi, Epist. ad Leibnitium, Wolffen-
buttel, 1703. Cf., also, Epist. G. G. Leibnitii ad A. C. Gackenholtziuni,
31. D.. de methodo Botqnica, § 10 ; Dutens, Ldbnit. <>p. om., 2, Pt. II., 173.
ADDITIONS AND CORRECTIONS 767
PAGK 335, note 1, line 1. Alter " 50," add : Eraser's Locke's Essay,
2, 69. So also Coste's translation, p. 360, ed. Amsterdam, 1742. Vol. 3,
p. 129, ed. in 4 vols., Amsterdam, 1774.
PAGE 337, note 3. Add: A 5th ed., Hamburg, 1887.
PAGK 343, note 1. Add: Also Gerhardt, Leibniz, math. Schrift., L, 2
[Vol.2], 1-208, Briefwechsel zwischen Leibniz und Hngens van Zulichem.
Also an earlier ed. in Pt. II. of Christ. Huge-nil aliorumque seculi XVII.
vironnn celebrium exercitationes mathematical et philosophical. Ex manu-
scriptis in bibliotheca Lugduno-Batavce servatis edidit. P. I. Uylenbroek,
Hagie Comitum, 1833. On the relation of Gerhardt's ed. to that of Uylen
broek, cf. Gerhardt, op. cit., II., 2 [Vol. 2], 9, 10. Gerhardt says, p. 10 :
" Es hatte mithin in jedem Falle auf die Sammlung Uylenbroek's Riick-
sicht genommen werden miissen, der die Leibnizischen Originate vor
sich hatte."1 Cf., also, New Essays, note to p. 16, line 22. ante, p. 723.
PAGE 344, note 4. Add : Professor Schaarschmidt having kindly sent
me Ulrich's note, and Ulrich's translation being rare and generally inacv
cessible. it is here given: " Dieser Knabe ward 1661 in einem Alter von
neuu Jahren in einem Walde von Litthauen von den Jaegern unter den
Ba'ren gefimden. Es war noch ein anderer Knabe bei ihm, der aber den
Jaegern entwischte. Dieser wehrte sich als man ihn fangen wollte anfang-
lich mit seinen Nageln und Zahnen ungemein tapfer, musste aber zuletzt
der Gewalt nachgeben. Er war iibrigens wohl proportionirt, weiss, hatte
blonde Haare und eine angenehme Gesichtsbildung ; man kommte ihn aber
durch nichts teandigen, vielweniger zu Kleidung und inenschlicher Nahr-
ung gewohnen. Er erhielt in der Taufe den Namen Joseph Ursinus."
The story is of course fabulous, it being impossible during the winter
to live in Poland without clothes, even were it anywise probable that
bears would live with children without eating them."
PAGE 349, note 1, line 3 from bottom. Dele "2d ed." — since, accord
ing to the author's " Avertissement," the work ktis not a 2d ed." of his
earlier work, entitled De la philosophie scholastique, 2 vols., Paris. 1850,
but an entirely new and independent work.
PAGE 353, line 5, "Prophetic vision." Leibnitz wrote a critical essay
on the Story of Balaam, which is found in Dutens, Leibnit. op. om., 4.
Pt. II.. 275-278. Wilhelm Brambach has published a monograph, en
titled f-iott fried Wilhelm Leibniz Verfasser der Histoire de Bileam, Leipzig.
1887, in which he gives an account of the various arguments for and
against its Leibnitzian authorship, maintains that Leibnitz was the author,
and gives Leibnitz's approved text of the piece.
PAGK 357, note 1. Add: Eraser's Locke's Essay, 2, 8(5.
PAGE 359, note 1. Add : Eraser's Locke's Essay, 2, 88.
PAGK 380, note 1. Add : On More. cf. Tulloch, national Theology
and Christian Philosophy in England in the 17th Century, 'Edinburgh,
768 LEIBNITZ'S CRITIQUE OF LOCKE
Win. Blackwood & Sons, 1872, 2, 303-409, the "ethereal vehicles,'1 396,
the "spirit of nature," 397.
PAGE 382, note 1. Add: Cf. New Essays, Bk. I., chap. 1, ante. p. 67,
and note to p. 67, lines 3, 4, ante, p. 732.
PAGE 382, note 2. Add: Cf. also, Dutens, Leibnit. op. om., 6, Pt. I.,
315, Leibnitiana, No. C., where Leibnitz says: " Henricus Moras statuit
pneexistentiam animarum, sive quod ariimse creates fuerint cum iiiundo,
quam sententiam Plato, Origines, aliique jampridem foverunt. Mea
opinio est, omnia, ut sic dicam, plena esse animarum vel analogarum
naturarum, et ne brutorum quidem animas interire."
PAGE 386, note 1. Instead of "Jacques reads," read: Jacques and
Janet read, etc.
PAGE 387, note 1. Add: In the "Bulletin des Sciences Mathe'ina-
tiques, 2d Series, Vol. 16, 1892, Pt. I., p. 18, in a review of C. Huygens,
(Envrea completes, La Have, 1888 sq., the following statement occurs:
" La courbe a-y = x2(a — x) rentre dans la categoric gene"rale des courbes
np+q-ryr = .»•*)(«__ x)?? qu'on appelle les perles de de SI use. Elle est une
cubique a centre (au point d'inflexion x — ^a, */ = o)." Cf., also, the letters
in this ed. of Huygens, Nos. 401, 403, 408, 419, 434, 436, referred to in
this review. In letter 461, the review goes on to say : " il est question
d'un rapport remarquable entre les deux perles a-y2 = xs(a — x} et >/4 =
jfi(a — ./•)." Cf., also, letter 435.
PAGE 388, lines 23, 27, 32, " §§ 23, 23, 24." These sections are numbered,
respectively, §§ 23, 24, 25, in Eraser's Locke's Essay, 2, 142-143 ; also in
Locke, Philos. Works, Bonn's ed. 2, 108-109; and in Coste's French
trans., Amsterdam, 1742, pp. 409, 410, 4 vols. ed., Amsterdam, 1774. 3,
248, 249.
PAGE 392, lines 6, 7. "The majority of the mixed modes nowhere exist
together." The French text of all the editions is: "La pluspart des
modes composes n'existent nulle part ensemble." The grammatical con
fusion of a singular subject and plural verb is probably occasioned by tlie
too condensed summary of Locke's statement, i.e. "Another reason that
makes the defining of mixed modes so necessary, especially of moral
words, is what I mentioned a little before, viz. that it is the only way
whereby the signification of the most of them can be known with cer
tainty. For the ideas they stand for, being for the most part such whose
component parts nowhere exist together," etc. (Eraser's Locke's Essay.
2, 158; Locke, Philos. Works, Bonn's ed., 2, 122); in Coste's trans.,
ed. 1742, p. 421, ed. 4 vols., 1774, 3, 276: "Une autre raison qui
rend la definition des Modes mixtes si necessaire, et sur-tout celle des
mots qui appartiennent a la Morale, c'est ce que je viens de dire en pas
sant, que c'est la seule vote par ou Von puisse avoir certainement la xiy-
uijication de la plupart de ces mots. Car la plus grande partie des idees
qu'ils signifient, etant de telle nature qu'elles n'existent nulle part ensem
ble," etc.
ADDITIONS AND CORRECTIONS 769
PAGE 404, note 1. Add: For a specimen of Euclid reduced to syllo
gisms, extracted from the very curious and rare Analyses Geometrical of
Herlinus and Dasypodius, cf. Aldrich, Art-is Logicce Rudimenta, ed.
Maiusel. Oxford, 1856, 3d ed., Appendix, note L, ad Jin., pp. 264-266.
Sir William Hamilton calls Herlinus and Dasypodius " zealous but thick
headed logicians," Aldrich, op. cit., p. 248, note r (Mansel). The 5th
proposition of the 1st Bk. is also analyzed by Mill, Logic, Bk. II., chap.
4, pp. 162, 163, 8th ed., New York, Harper and Bros., 1881.
I'AGK 405, note 1. After " Erdmann," add : Janet.
PAGE 405, note 2. After " Erdmann," add: Janet.
PAGE 408, note 1. Add : For a brief account of the Ramist-Aristotelian
controversy, rf. Piinjer, Gesch. d. Christlich. Religionsphilos., 1, 89-92 ;
Eng. trans., Hist, of the Christian Philos. of Religion, 1, 118-123.
PAGE 412, note 1. After " Erdmann," add: Janet,
PAGE 414, note 1. After " Erdmann," add: Janet.
PA«;K 414, note 2. Add: Fraser, Locke's Essay, 2, 185.
PAGE 425. At end of first paragraph of note continued from p. 424,
after •' 1, 187," add : letter to Conring, March 19, 1678, ibid., 1, 199 ; also
the writing with '-neither superscription nor place nor date," ibid., 4,
274 *»/., especially 277, 278.
PAGES 428, 429. " Certain theologians claim that the fire of hell burns
up separated souls." Cf. New Essays, Preface, ante, p. 62, and note to
line 10 from bottom, ante, p. 729, 730.
PAGE 431, line 10 from bottom. " Et quidquid Schola finxit otiosa."
I have not been able to find the author or source of the Latin line.
PAGE 432, line 11, " Lignum nephriticwn." A term used by the old
pharmacologists, signifying a wood, supposed to be that of the horse
radish tree, which has been used in decoction for affections of the kid
neys, — Nephritic wood, from the Greek vetypfc, a kidney.
PAGE 434, note 1. Line 2, after "1890)," add: Collectio Librorum
Juris Antejustiniani, ed. Krueger, Mommsen and Studemund, Berlin,
Weidmann, 1891, 1, 86; and line 6, after "1888)," add: Corpus Juris
Civil in. Berlin, Weidmann, 1893, 1, 23 b.
PAG E 445, note 1 . Add : On the history and significance of the terms (frav-
rao-tcu 0di/ra(r^a, " phantasma," cf. Siebeck, Gesch. d. Psychologic, Gotha,
1880. 1884, passim. Leibnitz in 'his letter to Thomasius, Feb. 16, 1666,
Gerhardt, Leibniz, philos. Schrift., 1,8, says : " Omnis color est impressio
in sensorium, non qualitas quaedam in rebus, sed extrinseca denominatio,
seu ut Th. Hobbes appellat, phantasma." On Hobbes' use of the term.
cf. his Works, and Lange, Hist, of Materialism, 2d ed.. 1, 288-289. For
Thomas Aquinas' use of the term, cf. Ueberweg, Hist, of Philos., New
York. 1875, 1, 449.
?0 LEIBNITZ'S CRITIQUE OF LOCKE
PAGE 447, note 1. Add: Fraser, Locke's Essay, 2, 237-239, and cf.
ibid., 2, 73, note 3: "An idiot, 'Such men do chaungelings call, so
chaunged by faries' theft.' Spenser, Faerie Queen, Bk. I., canto X. ;
also Shakespeare, Midsummer Night's Dream, ii., I., 21.''
PAGE 450, note 1, line 4 from bottom. After " pp. 312-314," add : also,
G. Croom Robertson, Philos. Remains, Williams & Norgate, 1894, pp.
274-278.
PAGE 462, note 1. Add : Cf. " Leibnitz and Protestant Theology," by
Professor John Watson, of Queen's University, Kingston, Canada, in
"The New World," March, 1896, Vol. 5, pp. 112-122. Cf., also, New
Essays, Bk. IV., chap. 7, § 11, Th. (2), infra, p. 474, and note 1 ; chap.
17, § 23, Th. (2), infra, p. 579, and note 1.
PAGE 464, line 6, " The number of the axioms." Mansel, in the Appen
dix to his ed. of Aldrich, Arlis Logicce Budimenta, 3d ed., Oxford, 1856,
p. 258, says: "The numerous attempts of Geometers to diminish or get
rid of their axioms have been steps in a wrong direction. The number
of axioms, instead of being diminished, should be very considerably in
creased ; and the errors that have hitherto prevailed on the nature and
foundation of Geometrical reasoning have been mainly owing to the man
ner in which many indispensable assumptions have been either omitted
altogether, or concealed among the definitions."
PAGE 465, note 1. Add : Cf. also addition to this note, ante, p. 768.
PAGE 474, note 1. Add: Cf. Neiv Essays, Bk. IV., chap. 6, ad fin.,
ante, p. 462, note 1, and addition thereto above ; chap. 17, § 23, Th. (2),
infra, p. 579, and note 1, and addition thereto, infra, p. 773. Dieckhoff,
Leibnitz Stellung zur Offenbarung, Rostock, 1888.
PAGE 481, note 1. Add: For Aristotle on the "middle term," rf.
Wallace, Outlines of the Philos. of Aristotle, 3d ed., 1883, §§ 23, 24,
especially the latter, and the passage of Aristotle there quoted. For the
history of the term, cf. Prantl, Gesch. d. Logik.
PAGE 482, lines 1-3. The text should read: "Made him reject alto
gether their use in the establishment of the truth, and goes as far as to
make them a party to confusion [of ideas] in conversation."
PAGE 483. note 1. After "Princip. Philos., II., §§ 1, 4, 11." add:
ed. Cousin, 3, 120, 123, 129.
PAGE 484, note 1, line 2. After " §§ IGsq.," add : ed. Cousin, 3, 133 sq.
PAGE 486, note 1. Add: Corpus Juris Civilis (Digest ed. Mommsen,
and paged separately), Berlin, 1893, 1, 718b.
Page 486, note 2. Line 3, after "locupletiorem," add: Corpus Juris
Civilis, Berlin, 1893, 1, 873 b ; after "Tit. VI., 14," add: ibid.. 1, 169 b ;
line 6, after "lucrum," add : ibid., 1, 300 a ; after " § 4, ad fin.," add : 1,
190 a.
ADDITIONS AND CORRECTIONS 771
PAGE 487, note 1. After " Tit. XVII., 1," add : Corpus Juris Civilis,
Berlin, 1893, 1, 868 a.
PAGE 487, note 2. Line 2, after "1888)," add: Collcctio Librorum
Juris Antejustiniani, Berlin, Weidmann, 1803 (lust. ed. Krueger), 1,
47 b ; at end of note, add : ed. 1893, 1, 120 a, 593 a.
PAGE 487, note 4. At end, add : On Sennert, cf. Lasswitz, Gesch. d.
Atomistik, 1, 436-454.
PAGE 492, note 3. Line 4, after "24, ad fin.," add: ed. Mommsen,
1893, 599b ; line 6, after " ib., 26," add : ib.\ 699 b ; line 7, after " 55,"
add: ib., 869 b ; line 8, after » ib., 129," add : ib., 871 b.
PAGE 495, note 1. Add : Cf., also, the quotation from the Theodicee,
P. II., § 184, infra, p. 635, note 2, ad Jin.
PAGE 495, note 2. Add: Cf., also, Leibnitz's letter to Conring (with
out place or date ; probably written at the beginning of 1670 — Gerhardt's
note), Gerhardt, Leibniz, philos. Schrift., 1, 160: Ego suppono cum
Carneade (et Hobbius consentit) Justitiam sine utilitate propria (sive
prresente' sive futura) summam esse stultitiarn longe enim absunt ab
liumana natura Stoicorum et Sadducseorum de virtute propter se colenda
superbse jactationes. Ergo omue justum debet esse privatim utile, sed
cum Justitise forma consistat in publica utilitate, sequitur quod non pos-
.sit accurate demonstrari haec propositio : homo prudens debit semper agere
quod justum est, nisi demonstretur esse quendam perpetuum vindicem
public* utilitatis (nam aliorum oculi metusque non ultra ligabunt pru-
dentem, quain quousque juvare aut nocere possunt) id est Deum, cumque
sensu manifestum sit, eum non esse semper vindicem in hac vita, super-
esse aliain^, id est esse aliquem Deum, et humanfim animam esse immor-
talem."
PAGE 496, line 7 of note continued from p. 495. After " 1877," add:
J. L. Lincoln, "Marcus Aurelius Antoninus," in In Memoriam John
Larkin Lincoln, 1827-1892, pp. 484-502, Boston, Houghton, Mifflin &
Co., 1894.
PAGE 506, note 1. After "Bohn's ed.," add: Eraser, Locke's Essay,
2, 315. Coste's translation of Locke's Essay, ed. 1742, p. 519, 4 vol. ed.,
1774, 4, 131, reads: "finis."
PAGE 510, note 1. Add: The note here referred to(c/., also, Coste's
translation of Locke's P^ssay, ed. 1742, p. 523, note 2, 4 vol. ed. 1774. 4,
141, note 2 ; translation of a part of the note, Eraser Locke's Essay, 2,
321, note 2), reads thus: " Ici M. Locke excite notre curiosite, sans
vouloir la satisfaire. Bien des gens s'e'tant imagines qu'il m'avoit com
munique cette maniere d'expliquer la creation de la matiere, me prie"rent
pen de terns apres que ma traduction eut vu le jour, de leur en faire part ;
mais je fus oblige de leur avouer que M. Locke m'en avoit fait un secret
a moi-merne. Enfin long-terns apres sa mort, M. le Chevalier Newton, a
LEIBNITZ'S CRITIQUE OF LOCKE
qui je parlai par hazard de cet endroit du livre de M. Locke, me decouvrit
tout le mystere. Souriant, il me dit d'abord que c'e"toit lui-meme qui
avoit imagine1 cette maniere d'expliquer la creation de la matiere, que la
pensee lui en e"toit venue dans 1'esprit un jour qu'il vint & tomber sur
cette question avec M. Locke et un seigneur Anglois [Le feu Comte de
Pembroke, mort au mois de Fevrier de la pre"sente annee, 1738]. Et voici
comment il leur expliqua sa pense"e. * On pourroit,' dit il, ' se former en
(jiielque maniere une idee de la creation de la matiere en supposant que
Dieu edt empeche' par sa puissance que rien ne put entrer dans une
eertaine portion de 1'espace pur, qui de sa nature est pe'ne'trable, e"ternel,
necessaire, infini ; car des-la cette portion d'espace auroit 1'hnpe'ne'tra-
bilite. 1'une des qualite"s essentielles a la matiere : et comme 1'espace pur
est absolument uniforme, on n'a qu'a supposer que Dieu auroit com
munique cette espece d'impe'ne'trabilite a une autre pareille portion de
1'espace, et cela nous donneroit, en quelque sorte, une idee de la rnobilite
de la matiere, autre qualite qui lui est aussi tres-essentielle.' Nous voila
maintenant de"livre"s de 1'embarras de chercher ce que M. Locke avoit
trouve bon de cacher a ses lecteurs : car c'est 1& tout ce qui lui a donne
occasion de nous dire, ' Que si nous voulions donner 1'effort a notre esprit,
nous pourrions concevoir, quoique d'une maniere imparfaite, comment
la matiere pourroit d'abord avoir e"te" produite,' etc. Pour moi, s'il m'est
pcrmis de dire librement ma pensee, je ne vois pas comment ces deux
-suppositions peuvent contribuer a nous faire concevoir la creation de la
matiere. A mon sens, elles n'y contribuent non plus qu'un pont contri-
bue a rendre 1'eau qui coule imm&liatement dessous, impenetrable a un
boulet de canon, qui venant a tomber perpendiculairement d'une hauteur
de vingt ou trente toises sur ce pont y est arrete' sans pouvoir passer a
travers pour entrer dans 1'eau qui coule directement dessous. Car dans
ce cas-la, 1'eau reste liquide et penetrable a ce boulet, quoique la solidite
du pont empeche que le boulet ne tombe dans 1'eau. De meme, la puis
sance de Dieu pent empecher que rien n'entre dans une eertaine por
tion d'espace, mais elle ne change point par-la la nature de cette portion
d'espace, qui restant toujours pe'ne'trable, comme toute autre portion d'es
pace, n'acquiert point en consequence de cet obstacle, le moindre degre
<le 1'impenetrabilite qui est essentielle a la matiere," etc.
Eraser, Locke's Essay, 2, 321, 322, note 2, above referred to, states that
••the idea of the creation of matter which Locke had in view in this
curious passage has occasioned various conjectures," and he refers to
that of Leibnitz in this passage, to Reid's in Intell. Powers, Essay II. ,
10 [ed. Hamilton, 8th ed., 1880, 1, 287 a], and to Dugald Stewart, Essay
II., chap. 1, p. 63. Reid thinks Locke agrees with Berkeley; Stewart
is almost tempted to think that Locke's idea of matter is "somewhat
analogous to that of Boscovich." Fraser says that "this 'dim concep
tion,' if it means that the material world may be resolved into a con
stant manifestation of God's power to man's senses, conditioned by
space, so far coincides with Berkeley's account of it ; he emphasises the
sensuous manifestation of divine power in selected spaces, as well as
ADDITIONS AND CORRECTIONS
the ultimate dependence of space on sense. Newton, it seems, suggested
that 'creation of matter' means, God causing in sentient beings the
sense-perception of resistance, in an otherwise pure space, — a theory
akin to Berkeley ism in its recognition of the Supreme Power, and to
Boscovich in its conception of the effect.'1
PAGE 513. At end of note, add : translation, Appendix, infra, p.
717 sq.
PAGE 522, note 1. After "Gerhardt," add: Janet,
PAGE 534, note 1. Line 1, after "Tit. VII., 1," add: Collectio Li-
brorum Juris Antejustiniani , ed. Krueger, Mommsen and Studemund.
Berlin, Weidmann/1878, 2, 52 ; line 5, after "Tit. I., 33," add : Corpus
Juris Civilis (Digest, ed. Mommsen), Berlin, 1893, 1, 667 b.
PAGE 534, note 2. Add: ed. Mommsen, 1893, 1, 665 a.
PAGE 534, note 3. Add: ed. Cousin, 1, 148.
PAGE 545. note 2. Add: New ed. of Bolsec, Vie de Calvin, by P. L.
Chastel, Lyons, 1875.
PAGE 548, note 3. Add : Fraser, Locke's Essay, 2, 379.
PAGE 552, note 1. Add: Cf., also, note to New Essays, Preface, ante,
p. 51, lines 11-13, infra, p. 727 ; also, New Essays, Bk. IV., chap. 20,
§ 11. Th., infra, p. 613, and note 1.
PAGE 567, note 1, line 3. After "296," add: Boliu's ed.; Fraser,
Lockers Essay, 2, 403-405.
PAGES 575, 576, note 1. Add: The doctrine set forth in the note is
closely allied to the inner light of the Quaker theology. Of. New Essays,
Bk. IV.. chap. 19, infra, p. 599, and note 1 ; also, Bancroft, Hist, of the
United States, Centenary ed., 1876, Vol. 2, pp. 87-92.
PAGE 579, note 1. Add: Cf. New Essays, Bk. IV., chap. 6, ad Jin.,
ante, p. 462, note 1 ; 7, § 11, Th. (2), ante, p. 474, note 1 ; also, on the
general philosophical question, " The Roots of Agnosticism," by Pro
fessor James Seth, in "The New World," September, 1884, Vol. 3, pp.
458-471 ; and on the special problem here under discussion, "Leibnitz
and Protestant Theology," by Professor John Watson, in " The New
World," March, 1896, Vol. 5^ pp. 102-122. Professor Watson's state
ment and criticism of Leibnitz's doctrine is admirable. He holds that
Leibnitz's distinction of two kinds of truth, truths of reason and trutlis of
fact, cannot be maintained, that " for a Being of infinite knowledge the
possible and the actual are coincident," that " the only possible reality is
that which is capable of being actualized," that there can be no choice
between hypothetical worlds, and that the existing world is the only pos
sible one, and is "necessary just because it is the expression of an abso
lute reason."
774 LEIBNITZ'S CRITIQUE OF LOCKE
PAGE 581, note 1. At end, add: Further references on the whole
subject: Lange, Gesch. d. Materialismus, 2d ed., 1, 182 sq ; Eng. trans.,
1, 218 sq. • E. Kenan, Averroes et VAverroisrne, Paris, 1852 ; 3d ed., Paris,
1865).
PAGE 585, line 6, " Motives of credibility." Cf. JVipw Essays, Bk. IV.,
chaps. 10, § 14, Th., ante, p. 554; 17, § 23, Th. (2), ante, p. 579, and
note 1. Cf., also, Dutens, Leibnit. op. om., 1, 680, where Leibnitz says:
"Motifs de croyance ou de credibility (comme ils les appellent) c'est-a-
dire, outre les raisons explicables de notre Foi, qui ne sont qu'un amas
d'argumens de differens degres de force, et qui ne peuvent fonder tous
ensemble qu'une foi humaine, ils demandent une lumiere de la grace du
Ciel, qui fasse une entiere conviction, et forme ce qu'on appelle la Foi
divine," i.e. " Motives of belief or of credibility (as they call them), that
is to say, besides the explicable reasons of our faith, which are only a
mass of arguments of different degrees of force, and which all together
can establish only a human faith, they demand a light of the grace of
heaven, which produces a complete conviction, and forms what is called
the divine faith."
PAGE 588, lines 16-19. '• What is only necessary by a physical neces
sity (i.e. founded upon induction from that which is customary in nature,
or upon natural laws which, so to speak, are of divine institution)," etc.
Cf. ante, p. 261, note 1, and addition thereto, ante, p. 761.
PAGE 606, note concluded from p. 605. Line 10, after "April 20-30,
1669, G. 1, 27," add: Appendix, infra, 650; line 20, after "p. 33," add:
translation, Appendix, infra, 631-651.
PAGE 613, note 1. Line 1, after " p. 51, line 11," add : and note thereto,
infra, p. 727 ; line 2, after " §§ 52, 90," add : ed. Cousin, 3, 217, 256 ;
line 5, after » § 48 sq.," add: ibid., 3, 214 sq.
PAGE 634, line 24, ''Gilbert." William Gilbert, 1540-1603, private
physician to Queen Elizabeth, was " the first real physicist and positively
methodical experimenter known in the History of Physics before Kepler
and Galileo." By the experiments and discoveries published in his De
magnete magneticisque corporibus et de magno magnete telhtre, Physiologia
nova, London, 1600, later editions, Sedan, 1628, 1633, Frankfort, 1629,
1638, he became "the founder of the doctrine of magnetism and electric
ity." He called the latter vis electrica. For an account of his philoso
phy, cf. Lasswitz, Gesch. d. Atomistik, 1, 315-321 ; for his view of vacuum,
ibid, 319.
PAGE 634, line 24, " Gassendi." For Gassendi on the vacuum, cf. Lass
witz, Gesch. d. Atomistik, 2, 136 sq., 168-169.
PAGE 634, line 24, " Gericke." Cf. ante, p. 127, note 2. An account
of his views is given by Lasswitz, (resell, d. Atomistik, 2, 293-300.
PAGE 634, line 25, " Digby." Cf. ante, p. 83, note 1. On Digby's phi
losophy, cf. Lasswitz, Gesch. d. Atomistik, 2, 188-207 ; on his view of the
vacuum, ibid, 199.
ADDITIONS AND CORRECTIONS 775
PAGE 641, line 11, "Anglus." Cf. ante, p. 634, note 1. A peculiar
notion of White's concerning the state of the soul separated from the
body, involved him in a controversy with the Bishop of Chalcedon.
White wrote two tracts on the subject: De Media Animarum Statu,
Paris, 1653, 8vo, Agr. 1659, 8vo ; Eesponsio ad duos Theologos Parisi-
enses Hen. Holdenum, et alium de Media Animarum Statu, 1662, 8vo.
The former, together with Hobbes' Leviathan, was censured by the
House of Commons in 1666. Archbishop Francis Blackburne, 1705-1787,
gives an extended account of both tracts in his own Historical View of
the Controversy concerning an Intermediate State. 1st ed., 1765, 2d, much
enlarged, 1772 ; in Vol. 3 of his Works, Theolog. and Miscellaneous, 1
vols., 1804. Hobbes and White frequently engaged in disputations, in
whith White commonly proved himself the abler dialectician.
PAGE 657, note 1. Add : On Leibnitz's dynamical views, cf. P. Harzer,
"Leibniz' dynamische Anschauungen, mit besonderer Rtichs. auf d.
Reform des Kraftemaasses u. d. Entwickelung des Princ. der ErhaUung
der Energie," in " Vierteljahrsschr. f. wissenschaftl. Philos.," 1881, Vol.
3, pp. 265-295 ; D. Selver, Der Entwicklungsgang der Leibniz"1 'schen
Monadenlehre bis 1695, Leipzig, 1885 ; M. Zwerger, Die lebendige Kraft
und ihr Mass, Miinchen, 1885 ; M. Planck, Das Princip der Erhaltuny
der Energie, Leipzig, 1887, p. 6 sq.
PAGE 679, note 1. Add: and additions thereto, infra, p. 733.
PAGE 692, note 1. Add : Translated also by Duncan, Philos. Wks. of
Leibnitz, with the title " On the Ultimate Origin of Things."
PAGE 705, line 10 from bottom (of text). The Latin text reads:
"Praeterquam finiam, adjicere placet, "'etc., of the first phrase of which I
have not been able to find any better rendering than that given in the text.
PAGE 712, note 1, at the end (p. 713). Add: Cf., also, Toucher de
Careil, Nouvelles Lettres et Opuscules inedits de Leibniz, Paris, 1857, pp.
412-437, — Note sur la loi de continuite, by the editor. The passage refer
ring to the letter here translated occurs p. 433. The note itself is a very
complete and valuable account of Leibnitz's principle. Cf., also, Nour-
risson, La Philosophic de Leibniz, Paris, 1860, pp. 221-238.
INDEX A
TO THE CRITIQUE OF LOCKE
"A in theology," applied to Antoinette
Bourignon, 603.
"A is not B," compared with " A is
non-B,"84.
A posteriori and a priori, eomplemen- j
tary methods, 315.
A posteriori truths, 499.
A priori proofs, 227 ; truths, 499 ; ar- ]
gument for existence of God, 503.
" A B " who says, says " A," 471.
Abridge, natural inclination of mind
to, 561.
Absolute, idea of, anterior to that of
limits, 158; anterior to all compo
sition, 162; is that of the infinite,
12, 17, 162; "in us internally," 163;
opposed to relative, 236.
Absolutes, the attributes of God are,
163: the source of ideas, 163.
Abstract, and concrete, how related,
128: thoughts have need of things
sensible, 78; entities, their reality?
178.
Abstracts affirmed of each other, not
always purely verbal, 497.
Abstraction, its process, 309; by it
we arrive at essences, 497 ; gives no
knowledge of real existence, 497.
Abstractions, when not errors, 51 ; to
be avoided, 225, 226.
Academic disputes, 478, 479.
Academicians, 421.
Accidental and contingent, 498.
Accidents, real beings, 154 ; when be
stowed miraculously, 428.
Accidents of bodies, not arbitrarily ac
corded by God, 428, 431 ; are not as
pigeons going into and out of their
holes, 428 : sometimes virtually
made substances, 428; if not modes
of their being or modifications of
their substances, then miraculous,
428; are suitable to their nature,
431 ; are not removed from ' reason
in general,' 431.
Acervi Ruentis, problem of, 328.
Acroamatic, 42, 272.
Act, how forced yet voluntary, 181,
184.
Actes de Leipzic, 227, 319, 502: des
Scavans, 14.
Action, essential to substance, 11, 218 ;
body and soul ever in, 111 ; two kinds
of, 175, 218 ; constant because nature
ever labors to put herself at ease,
194; perception, a form of, 218, 219:
motion, a form of, 218; that which
takes place in substance spontane
ously, 218; compared with passion,
218, 219 ; in substance when percep
tion is distinct, 219; a step towards
pleasure, 219 ; a change towards per
fection, 219; great business of man
kind, 223; consists in thoughts or
motions, 223 ; in Aristotle, 321.
Acts 17 : 28 quoted, 153.
Actus purus, God is, 113.
Adaruic language, the, its alleged pres
ervation in German, 298.
Adequate ideas, 17.
Adhesion of bodies, 123, 124.
Adverb, its use, 364.
'^Egean,' Bochart's derivation, 302.
^Equalia sequalibus, the axiom, 540.
Affinity, 259.
Aggregata, 361.
Aggregates, in what their unity con
sists, 235: artificial, 361; natural,
361.
Aggregations, beings by, 149.
Ah ! 368.
'Aha,' 301.
777
LEIBNITZ'S CRITIQUE OF LOCKE
'Ains,' 'anzi,' 367.
Air-gun, 466.
Albert, the Great, 278.
Albinus or Alcuin, 546.
Alchemists, 601 ; called « adepts,' 379;
write. only for ' sons of the art,' 379;
dangerous, 601.
Alexander the Great, 208; his dream,
267.
Algebra, 432, 571 ; does not require re
currence to ideas, 443; Vieta's use
of letters in, 468; Leibnitz proposes
use of figures in, 468; its use in ex
tracting roots, 571 ; not art of inven
tion, 573.
'Allein,' its equivalents in French, 366.
Alliance, 259.
Alliot, Dr., his verses, 3.~>2.
Alphabet, Chinese have no, 74 ; its
connection with sounds, 78.
Alps, derivation of word, 308.
Amadis de Gaul, 399, 431, 546.
Ambition, one's, should be to build
rather than destroy, 99.
America, lack of iron there, 525.
American, meaning Red Indian, 90,
359 ; savage regarded clocks as
alive, 388.
Analogy, as a rule of probability. 549 ;
foundation of rational hypothesis,
549; how employed by Huygens,
550 ; to be searched after. 553 ; mira
cles admitted in despite of, 553.
Analysis, 411, 412; its relation to in
vention, 412; infinitesimal. 440;
Pappus on, 521, 565; Conring criti
cises, 521 ; ultimate, difficult to ar
rive at, 521 ; involves a return by
synthesis, 565.
Anatomy, comparative, recommended,
553.
Ancient book, see Books.
Andradians, 593.
Andradius, on salvation of heathen,
592.
'Angebornen Ideen,' 3.
Angel, the change in its signification,
289.
Angelicus Doctor, 503.
Angels, as to their subtle bodies, 53 ;
according to the Fathers, 229; ac
cording to Aquinas, 230.
Anger, what, 173.
Anglicans, 613.
Animals, Cartesian view of, 62; con
servation of, in miniature, 62 ; auto
mata with souls, 66; immortal, 68;
reason upon particular ideas by con
nection, 145; do not form abstract
thoughts, 145; their love, its source,
145; have no knowledge of num
bers, 145; have no understanding,
178; rational, other than man, 244;
how the idea of, is produced, 310;
how the name is arrived at, 310;
speech of, 352, 353 ; and man con
nected, 549, 552: and 'man,' the
terms compared, 569.
j Animant, examples of, 125.
I Annuities, 540.
Anselm, his argument for the exist
ence of God, 18, 502, 503.
Antipathies, surprisingly common, 27,
37 ; the explanation of, 27, 28 ; de
serve the attention of educators,
29.
Antipodes, the ground on which re
jected, 217, 442 ; ' pretended heresy '
of, 443.
Antiquity, of value in religion, 618.
Antisthenes on virtue, 519.
aVTlTUTTia, 3.
Apagogical demonstration, 491.
Ape, a human ancestor, 353.
Aphorism, 476, 48(5.
Apiitm, 394.
Apollonius, 14, 108, 402, 416, 463, 573.
"Apologie du genre humain " of M.
Fabritius, 21.
Appellative names, 309,
Apperceptions, past, 46 ; depend on
attention and order, 76 ; we are often
without, 166.
Appetite, and hunger, distinguished,
170; tends to pleasure rather than
happiness, 207.
Appetitions, what? 177; apperceptible,
177 ; tend to go to their end directly,
not wisely, 195; can be directed by
reason, 196; motus prhno primi are
towards joy, 195.
Apuleius, ass of, 243.
Aquaviva, Claudio, 619.
Arabia Deserta, 259.
INDEX A
779
Arabs, influence on medicine, 371.
Arbitrariness, not in ideas but in
words, 325.
Archrei, 67.
Archelaus, his "law makes virtue,"
519.
Archimedes, 93; demonstrations in
physics, 414, 415; on equilibrium,
415, 416 ; has shown a square equal
to a circle, 424; further investiga
tions by him regarding circle, 424 ;
on curvilinears, 473 ; how he arrived
at quadrature of parabola, 475 ; his
definition of straight line, 522; on
the spiral, 573.
Areopagites, their practice of releasing
one whose case was too hard to de
cide, 186.
Argumenta, 398.
Arguments, the two, of the rhetori
cians, 529 ; mixed, 530 ; from greater
number, 530; Nicole on, 530.
Arguments in form, what? 559; a
recto ad obliquum, 5(50, 564; four
sorts, ad verecitndiam, 576 ; ad ig-
norantiam, 576; ad honiinem, 576;
ad judiciuni, 576; ad vertiginem,
577.
Aristides, 392.
Aristippus, on happiness, 518.
Ariosto, 398.
Aristotle, 392, 418, 466, 495, 521 ; his
entelechy, 66, 174; on time, 156; on
free acts, 180; on future life, 208;
on probability, 214 ; his definition of
motion, 320; his definition of light,
321 ; on materia prima, 383 ; defects
arising from the fact that some of his
writings were posthumous, 384 ; defi
nition of man, 384; defended, 385; his
14 Prior Analytics," 414, 416: as a
philosophic, writer, 41(5; assump
tions. 479; his KadbXov irp&Tov, 488;
additions to what he left concern
ing body, 495; his fT?™^^, 495; his
estimate of metaphysics, 495 ; how
he referred accident to matter, 498;
his " Posterior Analytics," 521; his
" Topics," 541; Locke's estimate of,
557 ; his disposition of the prem
ises in the syllogism, discussed, 568;
his expression " B is in A " justified
by reference to ideas, 569; is he
"saved"? 593.
Arithmetic, its propositions innate, 76,
78 ; can be presented apart from
sight or touch, 78 ; awakened in us
by touch, 78.
Armenian books, 372.
Armiuius, 72.
Arnauld, his " New Elements," 463,
464; argues against insensible
changes, 618.
Arrangement, its importance, 475.
Ars Combinatoria, pirated, 434.
Art of Signs, needed, 573.
Arts, advantage of cultivating, 525,
526.
Ass, golden, of Apuleius, 243.
Assassins, 196, 197.
Assent, degrees of, 529; often based
on memory of previous reasonings,
532, 533; such use of memory in, its
advantages and disadvantages, 533 ;
as a guide of action, 534,535; its
varieties, 537, 538 ; as assurance, 538 ;
as confidence, 538 ; as firm belief,
538; has varying degrees of proba
bility, 538 ; granted to Miracles and
Revelation, 553 ; founded on motives
of credibility, 554 : supernatural,
founded on Divine Grace, 554.
Association of ideas, a non-natural
often observable, 281, 282; ground
of acquired sympathies and antip
athies, 282; affects intellectual
habits, 282 ; source of the non-
natural, 283; depends on associ
ation of perceptions, 283 ; strength
ened by repetitions, 283, 284;
strengthened by " vehemence of im
pression," 284; influenced by "au
thority, party, custom," 284.
Assumptions, Aristotle's, 479.
Assurance, how belief becomes, 538.
Assyrians, doubts about history of, 545.
Asyllogistic, conclusions, 560, 561.
Asymptote, 209, 52::.
! Atom, defined, 53, 54.
! Atoms, 65, 68, 239; of Epicurus, 126,
132; of Democritus, 309; fortuitous
concourse of, folly, (515.
! Attention, 115, 165, 166; division of, a
means of securing sleep, 115.
780
LEIBNITZ'S CRITIQUE OF LOCKE
Attraction over distance, 56.
Attributes and modifications, distin
guished, 58.
Augustan Confession, 612.
Augustine, 410; on eternal truths in
Divine intelligence, 516; damning
infants unbaptized, 594; his " De
Utilitate Credendi," 616.
Augustus, 308: his " Brevarium Im-
perii," 610.
Augustus, Elector of Saxony, an
alchemist, 339.
Aumont, Due d', an antiquarian, 547.
Australians, supposed invasion of, 456.
Authority, how far to be yielded to,
616.
Avarice and ambition, the principle at
bottom of both wholesome, 212.
Avarice, its application to different
complex ideas, 313, 314.
Aventin, 546.
Averroists, 53.
Axioms, are they indispensable? 12;
should be demonstrated, 18, 72, 99,
107, 175, 473, 518; truths other than
self-evident, 464 ; secondary, should
be reduced to primitive, 464 ; primi
tive, 464; primitive, are identicals
and undemonstrable, 464 : its par
ticular and more general meaning,
469; in what sense prior to other
parts of knowledge, 470; other
truths alleged to be as evident as,
471 ; the result of discarding, 472 ;
their use in geometry, 473; should
be assumed with caution, 518; when
the secondary may be employed, 524 :
their principal use to connect ideas,
" B in mathematics," used by Bertrand
la Coste, 603.
Babylonians, doubts about mathe
matics of, 416 ; doubts about history
of, 545.
Baldness, the problem concerning, 328,
353.
Baptism, conditional, 244, 343, 344.
Barantoli, could not understand ' hal
lowed,' 103.
Barbarism and cultivation contrasted,
96, 97.
Barclay Quaker theologian, 599.
Earner, his Prodromus, 487 ; suggests
abridgment in medical works, 488.
Battles, almost no good account of,
543; those of Livy imaginary. 543;
Dahlberg's plans of, 543.
Bauhin, 308.
Baumgarten, his story of the Sauton,
89.
Bayle, 66, 507.
I Beasts, men distinguished from, by
innate knowledge, 76.
Beatific vision, 575.
Becan, 303.
Beda, 295.
Being, have idea of, because we are
beings, 76; knowledge of. how de
rived? 100: some have no word
for, 103; God, finite spirits, and
matter may be modifications of a
common, 154: corporeal, knowledge
of, given in sensation, 229 ; spiritual,
knowledge of, given in sensations,
229; thinking, if thought comes
from, such Being is God, 501; one
original, reasonable to believe that
there is, 501 ; thinking, can it come
from a non-thinking source? 505;
eternal first, cannot be matter, 506.
Beings, outside of us, are they demon
strable ? 469 ; eternal, may there be 'I
501 : may this state of things origi
nate in a concurrence of? 501.
Belgian Confession, (512.
Belief, how it becomes assurance. .~>:;H ;
not according to wish, but sight of
most apparent, 615; can be indirectly
influenced, 615 : founded on slight
reasons, explained, 616.
Bellarmine, 621.
Bernier, 64.
Beverovicius, his book on medicine,
624.
Beyerling, 622.
Beza, his views of Eucharist, 612.
Blind, their opinion of scarlet, 128,
321 ; have learned geometry, 139 ;
may learn optics, 139; can speak
pertinently of light and color. 305.
Bochart, 302.
Bodies, " two cannot be in same place
at same time/' the statement con-
INDEX A
781
sidered, 83; impenetrability of, 83;
extension of, and equality of space,
not inseparable, 127; act only by
impulse, 132 ; do not act where they
are not, 132; in what sense neces
sary agents, 183 ; do not remain
same in appearance, 240; of entel-
echies are machines, 362; of entel-
echies, imperishable, 362; of en-
telechies, an infinite replication of
inanimates, 362.
Body, never without motion, 11, 24,
47, 110; least impression upon,
reaches its entirety, and therefore
to part whose motions correspond
to actions of soul, 25; Leibnitz al
leges a change in Locke's views as
to, 38; and mind, their differences
not modifications, 58; and mind,
exact correspondence between, 117,
182: to say it is extended without
parts unintelligible ? 118 ; acts (agit)
when spontaneity in its motion, 219 :
is passive (patit) when urged or hin
dered by another, 219; possesses
an image of substance and action,
219 : as composed of parts, not one
substance, 219 ; its unity comes from
the thought, 219; like a flock, 219;
organized not the same but equiva
lent, 241; Descartes' view of, 483;
can it be only in one place at same
time, 466, 589; substance of, does
not consist in extension or dimen
sion, 612; glorious of Jesus Christ,
612 ; glorious, its local presence, 612 ;
glorious, its sacramental presence,
612; glorious, its miraculous pres
ence, 612.
Bodies, mechanical affections of .colors,
sounds, etc. how explained, 441;
movements of, correspond to, but
do not resemble, affections of soul,
441 ; their connection with soul ex
plained by Pre-established Har
mony, 441 ; the statement that two,
cannot be in the same place at the
same time, discussed, 466 ; the state
ment true if body be an impenetra
ble mass, 466 ; the statement not true
of real body, 466 ; the statement
only true in natural order of things,
467; knowledge of, being increased,
495 ; knowledge of, acquired by ex
perience, 524; knowledge of, ac
quired by rational and regular
experiment, 524 ; investigation of
internal parts of, most useful of our
pi'esent efforts, 552.
Boehme, Jacob, 298 ; Teutonic Philoso
pher, 603; believed to make gold,
603.
Bohlius, 366.
Boldness, 223.
Bolsec, his slanders on Calvin, 545.
Boniface, 443.
Bouosus, wherein his drinking might
be praised, 263.
Book, never formed by throwing type
together pell-mell, 422.
Books, ancient, to be investigated, es
pecially on medicine, 372 ; Chinese,
372.
Boreas and the traveller's cloak,
613.
Borgia, Francis de, how he reduced
his wine, 193.
Bouhours, his Art de Penser, 144.
Bouillaud upon the spiral, 573.
Bouquetin, ibex, 394.
Bourignon, Antoinette dc, an enthusi
ast, 599, 602, 603.
Buutan, 91.
Boyle, Chevalier, 324; denies absolute
rest, 47 ; concludes that everything
in nature takes place mechanically,
527.
Brahmins, 372.
Brenner or Pyrenees, 308.
Brocards, require reform, 486.
Bruguolus, 106; Brugnol, 107.
Brusquer, 370.
Brutes, their knowledge, 44; their
"consecutions," 44; have imperish
able souls, 62, 113.
Brutus, origin of name, 308; and the
Britons, 546.
Bubbles, as memories, 513.
Bucephalus, 308.
Buratini, 150.
Buridan's ass, 116.
Burnett, Thomas, a correspondent of
Leibnitz. 6.
' But,' its different significations, 366;
782
LEIBNITZ'S CRITIQUE OF LOCKE
its equivalents in French and Ger
man, 366; its derivation, 367.
Caedmon, 295.
Caesar, 308, 575.
Calvin, his strong views of Eucharist,
612.
Caraillus and the Gauls, story con
tradicted, 545.
Campanella, 67.
' Candle of the Lord,' 437.
Cannon-halls, why piled? 570.
Canon, general, 468.
Capacity, 149, 174.
Capito, 308.
Cardan, 67 ; on the logic of the proba-
ble, 566.
Caribbees, their cruelty, 89.
€arlowitz, peace of, 259.
Carrington, his life of Cromwell, 543.
Cartesians, 02, 66, 67, 68, 113, 126, 133.
Cartesians, their appeal to ideas, 13;
perplexed by souls of brutes, 62 ;
on space and matter, 128 ; on space
and extension, 129; on transfer of
motion, 176; on souls giving new
direction to force, 233; cannot
demonstrate real external existence,
319 ; their first truth, 410, 460 ; their
argument (the Anselmic) for exist
ence of God, 502; their grooved
particles, 613.
Casati, 176.
Casaubon on the Sorbonne, 478.
Casimir. King of Poland, and his forest
child, 344.
Cassowary, sign of a complex idea, 357 ;
exact idea of its skin might distin
guish it, 357 ; "wide nails " wanting
to make it a man, 384, 385.
Castor and Pollux, with one soul,
114.
Cause, final, 224, 556; proximate for
mal, 337.
Cause and effect, 237 ; can they be ex
pressed apart from action ? 224.
Causes, efficient, parallel in all worlds,
440 ; final, various, 224, 440.
'Cavalcar,' 222.
Cebes, Table of, 436.
Celery-plant, 394.
Censors, 593.
Censures, Theologic, 537.
Cependant, its use, 367.
Certainty, in human knowledge, 15 ;
of truth and of knowledge, 453 ; ex
perimental, 460 ; moral or physical,
distinguished from metaphysical or
necessity, 462 ; what ? 513.
Certitude, mathematical, 13 ; the place
of particular demonstration in, 318,
403; depends on certain universal
propositions, 403.
' Chain of reasoning,' 561.
Chance, what ? 203 ; a mathematical
treatment of games of, 541.
'Chancellor of England, the,' 526.
I Change, what ? 174.
Characteristic, a universal, 453, 469.
Chemistry, its infido successu, 331.
Chemnitius, 592.
Chess, Arabs play, by memory, 152.
j Chiliagon (figure of a thousand sides) ,
269, 272, 273.
Children, why they have no knowl
edge of innate principles, 76; their
exposure, 89.
Chimerical, difficulty of affixing epi
thet, 277.
I China, race-mules in, 345; Jesuits in,
594.
Chinese, geometers, 22 ; alphabet, no,
74 ; drawings, 13(5 ; writing, 140 :
language, 287, 452, 453 ; Golius's opin
ion about language, 287, 292 ; salva-
bility of, according to Jesuits, 59-A.
Choices, suspensory power exists over.
186; different, prove varying opin
ions of good, 207; future life should
influence our, 208; man's, never
wrong if present alone regarded,
208.
Christmas eve, superstition concern
ing, 470.
Chronicles, II.. (5:18, 158.
Chrysostom, on natural piety, 591.
Church, ambiguity of term, 271; its
relation to controversies, 617, 61S.
Cicero, 308 ; on the sight of the beauty
of virtue awaking love to it, 192;
on the praise of virtue, 264; on the
existence of God, 500.
Circle, quadrature of, 603.
City of God, 53.
INDEX A
783
Clair-confus conceptions, are they pos
sible to the blind ? 140.
Clauberg on sources of German, 303,
304.
Clavius, 424.
Clearness, a species of certainty, 513.
Clelie, 223.
Clement, Second, his family, 544; of
Alexandria, 591.
' Coaxare,' as a stem, 298.
Codex Argenteus of the Euxine Goths,
295.
Codex juris gentium diplomctticus,
167.
Cogitationes csecee, 191.
Cohesion, causes traction, 54; in all
bodies, 125; its explanation as diffi
cult as that of thought, 231 ; not es
sential to extension, 231; does it
arise from pressure of ambient
fluid? 231,232.
Collective unity, what ? 149.
Collins, 593.
Color of gold would disappear if senses
move penetrating, 227.
Colors, their common properties, 323;
their divisions, 323; intimate nat
ure of, determined by analogy, 549.
Comenius, his air-gun argument, 466;
his " LuxinTenebris," 604; prophe
cies popular, 604.
Compactness, 123, 126.
Comparison, 144.
Compass, 525.
Complex ideas, 5, 147-149.
Composition of ideas, 144.
Compossible, capable of existing to
gether, 277, 334.
Compound direction of volition, 200.
Compulsion, physical, what? 182, 183;
moral, what? 184.
Conatus, 177, 224.
Conceptivity, creature's measure of
nature's power, 60.
' Concreate,' 80.
Concrete terms, best to be employed,
226.
Concrete and abstract, how related,
128.
Concurrence, 144.
Condensation, 124; there is none, 127.
Condensations, real, 466.
Conditions, an early thesis upon, re
ferred to, 434.
Cone, an illustration of the gliding
of the sensible and rational into
each other, 549.
Confidence, 538.
Configuration can abide specifically
without abiding individually, 240.
Confucius, Jesuits' opinion regarding,
594.
Conjectures, 529, 538.
Conjunctions, 364.
Connaway, Countess of, 67.
Conring, 520 ; his criticism on Pappus,
521.
Consanguinity, 259.
Conscience, borne witness to by best
part of race, 90 ; remorse of, 91 ;
" laniatus et ictus " of, 91.
Conscious, we are not always, of hab
its and stores of memory, 46.
Consciousness of objects dependent on
attention, 115; what? 245; "silent
in forgetfulness," 247; cannot be
transferred, 247, 248; as a represen
tation, 248.
Consecutions of animals, 69, 145.
Consent, general, may come from tra
dition, 72.
Consequence discussed, 213.
Conservation of souls, 52 ; of animals
in miniature, 62.
Consideration, 166.
Consistence, 126.
Consubstantiation, 611, 612.
"Containing" and "contained" not
same as " whole " and "part," 569.
Contemplation, 165, 166; of acquired
knowledge, 142; of innate knowl
edge, 142.
Contingence, angle of, 258.
Contingent truths, 183.
Continuity, law of, 50, 334, 552; ap
parently violated for reasons of
beauty, 552; why not evident be
tween man and beast, 552.
Continuum, 152, 1(50.
Contradiction, axiom of, a first princi
ple, 14; made use of always, 77;
how it may be employed in logic,
406, 407; how it may be employed
in mathematics, 406.
784
LEIBNITZ'S CRITIQUE OF LOCKE
Contradictories, 23.
Contrition, the act of, what? 591 ; how
it saves, 591.
Controversy, often due to the disput-
ers "speaking a different language
while meaning the same thing," 388.
Conversation, its nature, 341 ; angelic,
341.
Conversion, principle of, how used in
logic, 407.
Copernican hypothesis, one opposed
to it maintained with zeal, 613.
Copernicans, 70.
Copernicus, 419 ; the detriment of sup
pressing his views, 614.
("optic books, 372.
Copy, force of a, as evidence, 541 ;
copy of a, its value in evidence, 541 ;
adds no weight to the original, 545.
Corban, 327.
Corinthians, II., 5: 10, 447.
Corollaries, 434.
Corpus delicti, 538.
Corruptio optimi pessima, 482.
Coste, Pierre, his translation of Locke's
Essay, 7, 27.
Coste, La, Bertrand, 603.
'Couaquen,' see 'Quaken,' 298.
Councils, advantage and disadvantage
of, 617 : their sphere according to
Henry Holden, 617, 618.
Count, to, what ? 160.
Creation, continuous, 16, 511 ; Locke's
statement concerning, that " its mys
tery is open to some extent to pro
found meditation," 509; probable
that Locke's hinted explication is
Platonic, 510; not more inconceiv
able than movements produced in
bodies by volition, 510; a gradual
connection in all its parts, 549; the
boundaries of its sensible and ra
tional regions difficult to define, 549.
Creator, ruled by nature of things, 431 :
produces and conserves only what
suits the nature of things, 431 ; pro
duces only what can be explained
by their natures, 431 ; gives no acci
dental powers detached from inward
constitution, 431 ; acts according to
general reason, 431; knowledge of
bis acts, because of their reasonable
ness, rot beyond us, 431 ; difficulty of
comprehending his work not in their
reasons but their multitude, 431.
Credibility, motives of, 554, 579, 585.
Credulitate, de, oath, 530.
Crime, what ? 262.
Criterion of objects of sense : the con
nection of the phenomena, 422 ; veri
fication by truths of reason, 422 : yet
does not afford highest certitude, 422.
Criticism, 372.
Cromwell, Oliver, did he ever leave
the British Isles ? 543.
Crusca, La, function of, 18.
Ctesias, disagrees with Herodotus, 545.
Cud worth, 65.
Cuivls potest accidere, quod culqaam
potest, 492.
Cyrano, de Bergerac, his "Voyages,"
399 : fancies of, concerning beings in
the sun, 228, 229; in the moon, 551.
Cyrus, doubts about, 545.
Dahlberg, Count of, his plans of the
battles of Charles Gustavus of
Sweden, 543; his defence of Riga,
543.
Dalgarno, George, his artificial lan
guage, 292.
Darapti, 568.
Day and night, their succession in
twenty-four hours not necessary, 43.
De Dominis, 442.
De officio viri honi circa futwa con-
tinyentia, 605.
Deaf and dumb, those born, enquiries
concerning, 140.
Death, a sleep, 49, 52; cannot last
always, 53 : separation in, proves
movement of soul, 229.
Decahedron, a regular, an impossible
combination, 315, 354.
I Deduction, as an instinct and as a log
ical power, 88; employed by all, 88.
Definition, nominal, 17, 316, 339; real,
17, 316 : as applied to substances and
predicates, 317 ; empiric, only pro
visional, 324; external marks in,
sufficient for exact, 339; should be
capable of being substituted for
name, 340; dependent on exterior
of bodies imperfect and provisional.
INDEX A
785
342; often several, for an object,
392: whose possibility appears at
once to involve intuitive knowledge,
410; adequate, contains intuitive
knowledge, 410.
Degrees of assent, 532.
Deity, knowledge of, given by nature,
72 ; confirmed and rectified by knowl
edge, 72 ; readiness with which men
have received notion of, if tradi
tion or not, proves that it comes
from depth of soul, 72.
Aei iricrreveiv rbv /jLavdavovra, 519.
Democritus, 65 ; his promise of another
life, 66 ; his correct surmise regard
ing Milky Way, 277 ; atoms of, 309;
the principle of individuation in con
nection with his atomic theory, 309.
Demonstration, defined, 22, 556; phil
osophic, why inferior to mathemat
ical, 416, 417 ; not to be always ex
pected, 512 ; mathematical, its stages,
556.
Demonstrative knowledge, not so clear
as intuitive, 411 ; illustrated by a
series of mirrors, 411.
Demonstrative science founded on in
nate knowledge, 77.
Denial is positive, 131, 289.
Denominatio pure extrinseco., cannot
exist metaphysically, 236.
Denomination, intrinsic, 456; extrin
sic, 456.
Deo, omnia in, videre, 3.
Desargues, on tints and shades, 137.
Descartes, 62, 64, 67, 123, 46(5; advo
cated innate idea of God, 70 ; on fal
laciousness of senses, 134 ; on limit
less matter, 154; makes infinite
equal to indefinite, 154 : his idea
about pineal gland insufficient, 230;
his affection for squint-eyed persons,
283 ; his idea of body, 483 ; denies a
vacuum, 483: at La Fleche, 504; on
Bacon's method, 526; his expected
Telescope, 551 ; his hypothesis uncon
firmed, 552 ; employed the knowledge
of his time, 552 ; on solution of equa
tion of fourth degree. 572; applies
calculus to geometry, 573.
Description may fall upon the impossi
ble, 398, 399.
3 B
Desire, founded on uneasiness, 49;
what? 168-170, 189; its relation to
pain, 170; accompanies the passions.
198; in midst of joy leads to new
actions and neglect of present pleas
ures, 198; produces voluntary ac
tion, 199 ; aroused by happiness, 200 ;
its suspension is man's freedom,
202 ; its advantage, 202, 203 ; occurs
through insensible lassitude, 202 ; oc
curs through contrary inclinations,
202; may be brought about by
methodical mental processes, 203;
brought about by direct power of
mind, 204.
Despair, what ? 172, 173 ; reasons
against, 437.
Despreaux, 97.
Determination, of will, what? 183;
useful and necessary, 205 ; needful
to effective choice, 205 ; does not
necessitate, but incline, 206 ; an in
clination rather than a necessity,
206 ; when founded on reason gives
largest freedom, 206 ; resting on
final result necessary to freedom,
205 ; its strength in superior beings
does not limit their freedom, 205 ;
"confirmation" of unfallen angels
rests on, 205; is in God, and is not
inconsistent with perfect divine free
dom, 206.
Determined, all things in soul are,
15.
Diagram, 435.
Dialogue, advantages of that form of
writing, 42.
" Diaphanous " in Aristotle, 321.
Die cur hie, 166, 203.
Dichotomies, 200; their use, 312.
Dictionaries of simple ideas observed
in individuals of each species desid
erated, 394 ; with small illustrations,
recommended, 394; Chinese have il
lustrated, 395; "the most excellent
of," 49.
Difficulties often created and then
lamented, 460.
Digby, Chevalier, 83.
Digests, 272, 486.
Diogenes wishes to make, a Platonic
man, 385.
LEIBNITZ'S CRITIQUE OF LOCKE
Diopliant, 573; on reduction of equa
tions, 571.
Dioscorides, 371.
Discernment, 143-147.
Discovery, finds general truths, 474;
a chance example often assists in,
475 ; ways of, might be systematized,
476; sometimes arrived at by ra
tional but extended circuits, 476.
Discussion, art of, its importance, 477 ;
frequent in beginning of Reforma
tion, 477 ; art of, needs remodelling,
478; "last word" in, 478; assump
tions in, 479; confusion in, from
want of axioms, 47'.); rules and ex
ceptions in, 480: replications and
duplications in, 480; cavilling in,
reprehended, 481 ; its academic for
mulae not to be paraded in conver
sation, 482; of matters of faith,
regarded by some as of the devil,
610.
Disease, like a plant or animal, 488.
Disparates, what? 405, 406.
Disposition, what? 223.
Dispositions, remains of past impres
sions in the soul, 143; conscious of,
on occasions, 143.
Distance, what? 149; of places and
times, congruity between, 209.
Distinct, 267.
Distinctions, virtual, of the Scotists,
587.
Diversity, involves an internal princi
ple of distinction, 238; time and
space are helps to recognize, 238 ; not
destroyed by interpenetration, 238.
Divine grace, a pleasure, 192.
Divini, Eustachio, 613.
Dogmatists, 420.
Drabitius, 605.
Draudius, 626 ; his method criticised,
627.
Dreaming, 165, 166.
Dreams, absence of, no disproof of
soul's activity, 115; leave marks on
brain, 117': shall we infer from inco-
herency of, that rational thought de
pends on body? 117 ; of persons and
places before they have been ceen
by dreamer, 514.
Drinking, a virtue, 263.
: Drunkard, under the illusion of time,
209.
Duration, 155-158, 220; idea of, how
awakened ? 156 ; could perceptions
give idea of ? 156 ; how measured ?
156 ; not comprehensible in all its
extension, 158 ; indicates possibilities
beyond supposition of existences,
158 : infinite, an easier conception
than an infinite expansion of space,
158.
\ Duties and sins, how they differ -from
virtues and vices, 261, 262.
i Dynamics, 440.
j Eau, its derivation, 302.
! Ebenbitar, 371.
["Ecclesiastical Polity" of Hooker,
quoted, 566.
E chant illon de Reflexions sur I' Essay
par Locke, 6.
Economic faculty as an Judicial term.
627.
Ecstasy, 165, 166.
Ecthesis (mathematical), 464, 556.
Effect, often confounded with cause,
137.
Effort, 174.
Ego, spiritual, preserved, 241 ; has no
parts, 247 ; same physical preserved,
247.
Egyptian, geometers, 22, 416: vases
religiously decorated, 390.
Elbe, 308 ; applied to all rivers in Scan
dinavia, 308.
Embryology, question in, 347.
Empiricism, liable to mistake, 44 : un
reasoning, 556.
Enchiridion sapientias, proposed, 610.
Encyclopedia, 623-625.
Endoxon, 418.
Enigma, its use, by Pythagoras, 379 ;
by Orientals, 379.
Entelechy, 66 ; Aristotle's view of, 174 ;
Leibnitz's view of. 174.
Entelechies, when they are souls, 175;
perception belongs to all, 218; sub
stantial unities, 234: primitive, their
bodies machines, 362.
Enthusiasm, Locke's thoughts on, 31-
37 ; defined, 32, 33,596, 597 : difticult
to rescue its victim, 33, 600, 601 : its
INDEX A
787
ground examined, 33, 34, 596; how
to guard against, 35 ; rests on a feel
ing of revelation, 597 ; at first had a j
good signification, 598.
Enthusiast, a young lady, 600.
Enthusiasts, may become a dangerous
sect, 600.
Euthymeme, 73, 481, 559, 563, 564.
Envy, what ? 173.
Epictetus, 495.
Epicurean atom, 54 ; tendency to mo- !
tion when at rest, 380 ; tendency to j
motion is gravity, 382.
Epicureans, 501.
Epicurus, 126; his life exemplary, 535. j
Epiphany, 361.
Episcopius, 179.
Equation, method of solution often
depends on good luck, 572.
Erasmus, 591.
Errors, arise from false principles as- ,
sumed as once proved, 37; arise from |
carelessness in deduction, 37 ; arise |
from the bias given by emotion, 37, |
38 : arise from little time left for \
study by necessary occupation, 607; i
of people of leisure, 608 ; of people j
of narrow logical power, 608 ; are j
they dependent on nature of soul or
lack of exercise ? 608, 609 ; often due
to power of example, 609; enter
tained by those who lack will to
study, 609; from false measures of
probability, 610; arise from earliest
education, (ill; arise from believing
teachings of an accepted communion,
611; from accepted hypothesis, 613 ;
from improperly understood author
ity, 616: the sin of, 607, 616: not so
common as apparent? 620.
Essay, concerning Human Understand
ing, by Locke, its translation into
French, 4, 27, 65 : its successive edi
tions and abstracts, 4, 26, 27 ; its con
tents, 4, 6, 70; its translation into
Latin, 37, 65; errors corrected in,
and additions made to, 26, 27 ; com
mended, 567.
Essence, its import, 315; 'nominal'
and ' real,' is the terminology cor
rect? 315, 316, 385; and definition
distinguished, 316 ; and property dis
tinguished, 317 ; how perpetual, 318 ;
iu'to which opinion enters, 328; half
nominal, 328; is it confined to sorts
or does it enter into individuals ? 331 ;
real, when chimerical, 356; more
than signs, 356 ; words may be used
regarding, 387; if unknown in some
respects, may be known in others,
387 ; our ignorance of, does not pre
vent their existence, 387 ; a real, may
be assumed by means of a reciprocal
proposition as to genus and species,
457; of substance, makes its quali
ties emanate from its depths, and
makes itself known by them, 460;
knowledge of, arrived at by abstrac
tion, 497 : and existence, 498; natu
ral as applied to accidents, 498.
Eternal truths, their reality in connec
tion with ideas, 516; require either
created or Divine mind for existence,
516 ; the Divine mind their constant
region, 516.
Eternity, how notion originates, 158;
in what sense a positive idea of, pos
sible, 164; we have a just idea of,
but no image, 274.
Ethics, a true philosophy strengthens,
66; though demonstrative has its
innate principles, 85, 86 ; its maxims
often only convenient rules, 86 ; its
truths not independent, 86 ; has prin
ciples which are not demonstrable,
86; has principles not known purely
by reason, 86 : its maxims sometimes
known by instinct, 86, 89; deriva
tive truths of, 87 ; depends on dem
onstrations furnished by natural
light, 89; are not perceived at once,
89 ; obedience usually unreasoning,
90: its impulses not invincible, 90;
natural impressions serve in, only as
aids to reason, and indices to the
plan of nature, 91; natural instincts
not beyond, but in spite of exceptions
tend to what is right and decent, 91 ;
if geometry were as much opposed
to men's inclinations as. it would be
equally contested, 93; best treated
by definition, 392; and metaphysics.
495; geometry might be applied in,
524; what it comprises, (521.
788
LEIBNITZ'S CRITIQUE OF LOCKE
Eucharist, opinions concerning, 611 ; !
participation in, of thought, (512.
Euclid, 14, 22, 44, 93, 108, 403, 404, 416,
463, 465, 467, 471, 473, 491, 522, 523, I
613 : does not expressly use ' ' the
whole is equal to the sum of its j
parts," 471; does use " the whole is j
greater than its parts," 471 ; axioms j
of, diminished hy Roberval, 473; his
definition of a straight line obscure
and gives rise to difficulties, 522 ; his
demonstrations, arguments in form,
559, 560.
Euphorbus, 21, 100.
Evangelicals, their opinions on the
Eucharist, 611.
Evidence, luminous certainty, 513.
Evil, what? 167, 200, 202, 260: its ad
vantages, 170. [198.
Evils, present, possible remedies for,
Example, its force, 609.
Exclusion, method of, 413.
Excommunication, 264.
Existence, our own, known by intui
tion, 18, 439, 498, 499; of God, by
demonstration, 18, 439, 499, 500; idea
of, whence ? 130, 220 ; real , one of the
"four sorts of agreement or disa
greement," 400 ; beyond the mind,
how determined, 419 ; of things
besides God and ourselves, how
known, 499; earliest apperceptions
of, furnish earliest experiences, 499 ;
of God, the Lockian, Anselmic, and
Cartesian arguments for, 499-505
Exoteric, 272.
Experience, twofold, 4 ; not sole source
of truth, 11 ; not everything in
physics, 18; never assures of per
fect universality, 22 ; never assures
of necessity, 22 ; determines to
thoughts but does not furnish ideas,
110 ; its first truth, 501 ; not a good
thing to judge by, 582.
Experimenting, Bacon put art of, into
maxims, 526.
Extended, the, what? 152.
Extending ideas, 144.
Extension, what? 152, 160, 163, 220 ;
different from matter, 155 ; not nec
essary to existence, 430. [129.
Extensions, are there two? 127, 128,
External causes of sensation, reality
of, 511, 512 ; if a dream, yet suitable
to circumstances and hence satis
factory, 512 ; have an assurance of,
as certain as pleasure or pain, 512.
Fabri, his " Summa Theologiae," 586:
his view of movement of sun, 613.
Fabritius, or Fabricius, M., 21, 102.
Factuni, in, the action, 486.
Faculty, more than the possession of
ability without using it, 80 ; requires
not merely object but disposition
towards object before it will act, 80 :
not full explanation of, mind's easy
consent to certain truths, 81 ; naked,
does not exist, 110, 143, 174, 204, 428.
Faculties, have disposition and ten
dency to action, 110; how they act,
179 ; secondary, more than relations,
185 ; naked, little goblins as it were,
431; their limits and sphere, 525;
lessons to be drawn thence, 525.
Fairies, how their transformations
would be regarded, 244, 245.
Faith, the analysis of, 555 ; what ? 580,
583; grounded on reason, 580, 582:
and reason, their distinctive limits,
583; proper matters of, 584; requires
internal grace of Holy Spirit, 585 :
does not refuse a knowledge of
reasons, 585 ; cannot receive what
subverts all belief, 587; implicit.
Bellarmine on, 621; involves a rea
sonable docility, 621.
False judgment, in allowing the "dis
tance" of a pleasure or pain to
determine its value, 209; depends
on limited capacity of mind, 210:
by which the absent is annihilated.
210; distinguished from bad taste,
210 ; as to the greatness or certainty
of consequences, 212; in hazarding
a greater good for a less, 213 ; causes
of, 214; the reckoning required to
escape, 214, 215 : in accepting first
pleasure which comes to hand, 216 ;
to expose oneself to a possible dan
ger in next life, 217.
Falsehood, its nature, 452.
Family names, 258.
Fanatic, .".3, 596.
INDEX A
'89
Fear, what ? 172.
Feel, without knowing it, 191.
Felicity, what? 87; reason prompts
to, 87.
Ferrari, Lewis, his equations, 572.
Feuille inorte, an idea of the color,
how conveyed to peasant, 391.
Figural arrangements, 145.
Figure, what? 151, 160; scarcely a
simple mode, 152; does not pass de
subjecto in subjectum, 240 ; knowl
edge of, does not depend on " imagi
nation," 273.
Figures, in logic, 560; principal one,
407 ; less principal ones, 407 ; in
direct or fourth, 407.
Fingers, counting on, 482, 562.
Finite, the concept of, how arrived at,
12.
Finnish, 297.
Fire, not known by Marian Islanders,
104 ; its intimate nature more than
probable, 549, 552.
Flacius, 295.
Flieyende Gedanken, 182.
Florileges, 548.
Fludd, Robert, his <; Philosophia Mo-
saica," 63.
Fluid, perfect, of Cartesian, impossi
ble, 126.
Fluidity, in all bodies, 126.
Fontenelle, on plurality of worlds, 550.
Force, 174 ; as active power, 174.
Form, of Man, not enough to consti
tute man, 244; of words, what?
304, 305; arguments in, what? 559.
Forms, substantial, term inaptly em
ployed by scholastics, 347, 380 ; Des
cartes on, 348.
'•Formalities," 569.
Formido opposite or scrupulousness,
210.
" Forty-Seventh " proposition, its dem
onstration, how dependent on formal
logic, 565.
Foucher, Abbe', 420.
Fractions, their reduction to lowest
terms, 426.
Fractive faculty in grain-mill, 63.
Frauds, pious, sometimes more effec
tive than truth badly managed, 198;
to be avoided, 60(5.
Free, when a man is, 179; a man
awake is not, as to thinking, 181 ;
is, as to transference of his thoughts,
181 ; man is not, in certain circum
stances to certain ideas, 181 ; and
voluntary, term illustrated, 181 ; act,
in, what sense necessary, 183 ; beings
do not act indeterminately, 183.
Freedom, term ambiguous, 179; of
right, 179; of fact, 179; in its gen
eral sense, 179; in its particular
sense, 179 ; why a ball in motion not
an instance of, 180; properly cannot
belong to will, 184; of equilibrium
impossible, 184 ; what understood by
term, 184 ; without understanding, of
no use, 216.
Freedom of Will, opposed to internal
restraint, 179 j opposed to restraint
of necessity, 179; what it consists
in, 180, 202; not placed in a perfect
indifference or equilibrium, 203, 204 ;
does not throw off yoke of reason,
206; consistent with determination
of will, 206 ; founded in real happU
ness, 206.
Frenicle, M., 393.
Fromondus, 234.
Future life, how most men regard it,
196; its influence on choice, 208;
grounds on which wicked deem it
impossible, 217 ; favorable conject
ures concerning, 217 ; certitude of,
218 ; definition of, 246 ; its influence
on practice of virtue, 495, 496.
Galen, 407.
Galileo, on great antiquity of sun,
237; his condemnation considered,
613.
Gallic, language, 296.
Gallican confession, 612.
Gallows, a use of, 92.
Gassendi, 62, (54, 66.
Gaudium and Isetitia- compared, 172.
Gender, of no account in philosophical
grammar, 365.
jenealogical tree, to illustrate rela
tions, 236.
General notions, 43; •origin of, 71;
signs used by men deprived of
speech, 145; truths (propositions,
790
LEIBNITZ'S CK1T1QUE OF LOCKE
maxims), their universality not
proved by examples, 43; do not
come to us from the senses, 70 ; we j
tind them, do not form them, 70,
325; the senses give us occasion to
perceive them, 70; recognized as
soon as heard, 73 ; employed, though
not distinctly, in thought, 73; as
little in thought in reasoning as
muscles in thought in walking, 74 ;
not easily represented distinctly, 74 ;
why not, though innate, most vivid
in minds of children, idiots, and
savages? 85; their usefulness, 307 ;
how their truths may be deter
mined, 454; can they be applied to
substances ? 454-456.
Generality, its reality discussed, 313.
Genii, always joined to body, 52, 334;
their powers of perception, 228 ;
their alleged employment in future
ages, 551 ; are they animals more |
perfect than we? 574: there is much
they do not know, 574 : are in infi
nite gradation, 575.
Genus, physical and logical distin
guished, 58 : logical may exist be
tween heterogeneous things, 58 ;
its genealogy, 59; definition of, in
what case not provisional but per
fected, 456', 457.
Genus, and species, how they origi- I
nate, 310 : classification into, too j
little esteemed, 311 : and difference,
interchangeable, 313.
Geometry, employs pure reason, 22;
declines experience, 22 ; its proposi
tions innate, 7(5; in us virtually, 78;
can be prosecuted apart from sight
or touch, 78; mind awakened to by
touch. 78 ; its demonstrations would
be disputed if, like ethics, it op
posed our passions, 93 ; no exact cat
alogue of its axioms, 95 ; can be
learned by blind and paralytic, 139 ;
built on general axioms, 473 ; of
Greeks, 523; of Egyptians, 523; of
Chinese, 523 ; if follow senses in, fall
into error, 523; asymptotes in, 523;
permits us a glimpse of eternal truth,
523; ancient, the system described,
524.
Gerhardt, his introduction to the
Nouveaux Essais, 3-12; his esti
mate of Leibnitz's Meditationes de
Cogitations, Veritate et Ideis, 3.
Gerontophony, 222 ; name of, if be
stowed, would not give a new idea,
2>>o
Gesner, his Pandects, 626.
Gideon, 37.
Gobien, Father, 104.
God, apparent absence of idea of,
means only absence of occasion to
awaken it, 21 ; inclination to idea
of, from nature of soul, 72 ; penetra
tion of space possible to, 83; his
existence binds us to observance of
most moral precepts, 94 ; idea of,
innate, 94, 234, 493, 499; are there
nations which have no idea of?
Fabricius's denial, 102, 103; Locke
quoted on idea of, 103, 104 ; Locke,
in his description of the idea of,
approaches innate truths, 104 ; is
uctns purus, 113 ; the ground of
eternal truths, 153; the place of
things, 153; not extended, 159: im
mensity of, 159; by his essence,
source of possibilities, 159; by his
will, source of actualities, 159; the
principle of beings, 163; chooses
freely, yet is determined in choice,
183; continually produces, 230; fills
the universe, 230; in social connec
tion with us, 247 : and created spirits,
difference between, 332; extra- vel
supra-nmndana intelligentia, 382;
the supreme substance, 430; his pure
and universal act essential to all
changes in matter, 430 : his existence
demonstrable, 469, 499, 500; wit
ness to his existence, in our con
stitution, 41)9 ; impressions on the
soul which indicate, 499 ; evidence of
his existence, according to Locke,
equals mathematical demonstra
tions, 499; evidence of existence of,
arises from reflection on ourselves
and our own indubitable existence,
500.
God, existence of, Anselmic argument
for, misunderstood by scholastics,
502-504; imperfect but not a paralo-
INDEX A
"'.'I
gism, 504; morally demonstrable,
504 ; Descartes' argument for, from
" idea of Him in the soul," 504, 505 ;
his argument for, involves an un
proved assumption : that we have the
" idea," and that it comes from the
original, 505; proved by Pre-estab
lished Harmony, 505 ; nearly all ar
guments to prove, good, but must be
perfected, 505.
God, as Thinking Being, cannot be
material, since infinite and eternal,
508; absurd if all matter thinks,
508; absurd if part of matter thinks,
508; cannot be a mass of unthinking
matter, 50!) ; cannot be matter in
motion, 50(1; cannot be matter at
rest, 509; possible to attain a con
ception of how, made matter, 509 ;
how he gives existence to spirit is
more difficult to understand, 509;
his existence only has a necessary
connection with ours, 511.
Godwin, Franc, on the moon, 551.
Gold, result of its artificial production
if possible, 340; if a body had all the
qualities of, without malleability,
what then ? 357 ; on the determina
tion of its inner constitution, 393.
''Gold, all, is fixed" is an identical
proposition, 340; is it intelligible?
340: not known by agreement or dis
agreement of ideas, 460; can we cer
tainly know this for a truth, and
why? 460, 461.
Golden Rule, 88.
Golius, his theory on Chinese language,
287.
Gonzales, traveller to the moon, 342.
Goropize, what? 303.
Goropius, Becanus, his ridiculous ety
mologies, 303; claims that German
can contest honor of being primitive
language with Hebrew, 303.
Good, what, 107, 200, 202; its division,
167 ; when is one in possession of a,
172; how it may become an evil, !
202; how to be utilized, 207; moral,
260; moral, not an arbitrary institu
tion, 261 : moral, conformed to nature
or reason, 261; moral, founded in
God's rule of reason, 261 ; moral, not
dependent on legislation, 261 ; phys
ical, what? 261.
Goodwill, men of, 608.
Goose, Mother, the transformation in,
245.
Government, its claim on the absolute
freedom of its citizens, 433.
Grace, defined, 377.
Gradations in nature, 549.
Gratitude, an act of justice, 497;
foundation of Actio ingraft, 497.
Gravitation, 59.
Greaves, his theory as to the pyramids
of Egypt, 150.
Greeks, as geometers. 22 ; their admi
rable style in mathematical compo
sition. 416.
Green, its definition and analysis, 120,
320, 458.
Gretser, his ''Analysis of Faith." 618;
believes that a new article of faith
may be made through continuous
presence of the Spirit, 618.
Grimaldi, 394.
Grotius, Hugo, 494, 542.
" Ground, the, is everywhere the
same," a fundamental principle,
575.
Guericke, 127, 153.
Guerre, the personator, 310.
Guilt connected with inability, 5(54.
Habit, what? 223.
Habitus intellectuales,on these depend
the sects in philosophy, 30 ; formed
through Association of Ideas, 30, 31.
Hans Kalb, and his reputed calf's
head, 352.
Happiness, never consists in complete
possession, 194 ; and joy, 195 ; is op
posite extreme to misery, 200 ; is the
utmost pleasure of which we are
capable, 200; its lowest degree, 200;
is lasting pleasure, 200, 207; in
volves progression, 200, 201 : un
equal in different persons, 200, 201 ;
a "road through pleasures," 200;
reason will carry to, 200 ; shortest
way to, may not be best, 201 ; search
after, man's perfection, 206; dis
tinction between real and imaginary,
206 ; requires not so much knowledge
792
LEIBNITZ'S CRITIQUE OF LOCKE
as good will, 215 ; within reach of
idiot, 216.
Hardness, what ? 125 ; conceived by
reason, 126; terms preferred to that
of, 126.
Hardy, Leibnitz's discussion with,
465 ; believed the demonstration of I
Serenus paralogistic, 465 : com
mended by Descartes, 466.
Harlequin's stripping, an illustration
from, 362 ; in moon, 551.
Harmony, Pre-established, 11, 66, 334,
430, 553.
Hatred, what? 167, 173.
Health, its neglect commented on, 610.
Heap of thirty-six stones, illustration
from, 269.
Heat, relative to suitable organs, 133,
134: why sensation of, varies, 134;
wrongly said not to be in sun, 134,
135.
Heathen, salvation of, 594, 595; ac
cording to Romish doctors, 594.
Hebrew particle, a, has fifty significa
tions, 365.
Heliogabalus, if his soul is in the hog,
what is the hog? 241.
Hell fire burns up souls ? 428, 429.
Helmont, Van, 67.
Helmstadt, 581.
Herbert, Lord, his catalogue of innate
principles, 95.
Hercules, as the figure of, in rude mar
ble outlined by veins, so idea in
mind, 3. 46 ; known by gait, 357.
Herlinus, editor of Euclid, 404.
Herodotus, his one-eyed nation, 389:
disagrees with Ctesias, 545 ; accords
with Old Testament, 547.
Herostratus, a hero with some, 536.
Hippocrates, the physician, 48, 476;
the geometer, 527.
llifitortca, Dejide, of jurisconsults, 545.
Historical doubts, 545.
History, satire in, 542 : romance to be
expelled from, 542; details in, un
certain, 543; battles of, imperfectly
described, 543 ; writers of, posterior
to events they describe, worthy of
attention, 544; its value, 544, 545;
the private, of a people, when of
much value, 545 ; the fabulous in
history, 546 ; when stories of differ
ent and far-separated people agree,
it is a sign of truth in them, 546;
value of medals, inscriptions, etc.,
in, 547 ; of China much to be de
sired, 547 ; principal uses of, 547 ; of
clothing, valuable, 547 ; as a diver
sion, allowable, 548; ought to be
instructive, 548.
Hobbes, 450 ; writes against mathema
ticians, 93; afraid of ghosts, 283.
Hofmann, Daniel, 581.
Holden, Henry, his "Analysis of
Faith," 617.
Homicide, 385; as murder, 385; as
manslaughter, 385; chance-medley,
385.
Honor, as a principle of action, 536.
Honorius and his hen, 610.
Hooker, " the judicious," 566, 567, 570.
Hope, what ? 172.
Horace, 328, 335, 566.
Horodeictic faculty in watches, 63.
Horses, Welsh and Flemish, 237 ; witli
genealogical trees, 259.
Horseshoe, iron, when converted by a
certain spring into copper, changes
as individual, 240.
Hottentots, name for Holy Spirit
among, 103, 290.
" Houses, dwellers in small," we can
not expect much search after truth
among, 608, 609.
"Hundred Horses," an illustration,
617.
Hunger, as an illustration of mental
perception, 119.
Huygens, 150; gives up ' vacuum,' 16;
on logic in mathematics, 18 ; on
planetary men, 343; " De Alea,"
539; his " Cosmotheoros," 550; his
view regarding other planets, 550;
his use of analogy, 550.
Hybrida concluslo, 84.
Hybrids, do they multiply? 345.
Hypothesis, how proved, 520, 521 ;
must be combined with experimen
tation, 52(5; may lead to new dis
coveries, 526; is a help to memory,
526; must not be hastily framed,
526; greatly shortens the road to
discovery, 526; physical, cannot be
INDEX A
demonstrated, 565; zeal for, what? |
613 ; variable, 613 ; source of love I
for, 614.
Jfysteron proteron (le rebours), not j
arguing in a circle, 409.
" I and He " without parts, 247.
" I exist " carries with it highest evi- |
dence, 469.
"I think, therefore I am," not an j
axiom, 469; a truth of fact, 469; \
does not prove existence by thought,
469.
"I" and "existence" only God un- j
derstands how they are united,
469.
Icarus, 442.
Ice and the King of Siam, 530.
Jdeae adseq-uatss, what? 17, 278; pro-
prise, 3 ; what ? 3 ; necessity of hav- j
ing, 3; how in mind, 3.
Idea and image, confounded by Locke,
273; in a chiliagon, former possible
but not latter, 273 ; how they differ,
274.
Ideal world, 326.
Ideas, association of, 281 ; instances
of, 282, 283.
Ideas, when true and real, 14; the
origin of, not preliminary in philoso
phy, 15 ; come from within the soul,
15 ; when doubtful, 15 ; when chi
merical, 15 ; their possibility proved
a priori, 15 ; their possibility proved
a posteriori, 15 ; primitive or deriva
tive, 21; in what sense both sorts in
us, 21; denned, 21, 109; in what
sense can subsist un perceived, 21 ; j
innate, what? 22; and truths, how
related, 22 ; Locke's two sources for,
23: implanted, of Plato, 38; if they
come from without, then we should
be outside ourselves, 76; pure, op
posed to ' phantoms ' of sense, 78 ;
which do not come from sense, ad
mitted by Locke, 82 ; of sense con
fused, as also the truths founded on
them, 82 ; of intellect are distinct, as
are also the truths founded on them ,
K2 ; difficulties in, depend on amount
of attention required, 82; in mind
as habitudes, aptitudes, dispositions,
105; distinct, represent God, 109;
confused, the universe, 109; imme
diate, internal objects of thought,
109; not forms of thought, 109;
their perception, not themselves,
come through sensation and experi
ence, 111; pure and distinct, inde
pendent of the senses, 119; distin
guished from thoughts, 119 : which
come to us by one sense only, 121,
122 ; supposed to come to us by dif
ferent senses enumerated, 129 ; sup
posed to come by sensation and
reflection enumerated, 130; their
simplicity disputed, 130; their cause:
are they arbitrary, or have they an
expressive resemblance? 133; and
the secondary qualities which pro
duce them, their relations discussed,
133; resemble both primary and
secondary qualities, 133 ; resemble
motions which cause them, 134 ; from
sensations often unconsciously al
tered by mental judgment, 136 ; are
modes of thought, 143 ; internal ob
jects, 143; do not cease when not
matters of consciousness, 143; and
'bodily movements' 'correspond,'
181 ; and ' movements,' there is an
order and connection in, 181 ; or
notions, three degrees of, 217 ; ob
jects of, proposed classification of,
221; simple, those most modified,
223 ; collective, of substances, 234 ;
often applied by Locke to the objec
tive realities which the ideas repre
sent, 237 ; clearness and obscurity
of, 265; when distinct, 266, 267;
when confused, 267; confusion in,
when blamable, 267 ; confusion of,
sometimes lies in the composition,
269 ; sometimes in the bad use of
names, 269; sometimes in defective
analysis, 269; avoided to some ex
tent by precision in names, 271 :
real, 275; fantastical, 275; not
necessarily conformed to their foun
dations in nature, 275; the erro
neous opinion regarding, that God
has arbitrarily assigned them to
mark qualities, 276 ; association of,
281 ; privative, why should there
794
LEIBNITZ'S CRITIQUE OF LOCKE
not be ? 289 ; natural order of, 289 ;
same for all intelligences, 289 ; sub
stances and modes represented by,
306; of substances and sensible
qualities more fixed, 300 ; reflective,
enter into those of things, 306 ;
how they become general, 307 ; ab
stract, may be attributed to one
another, 313, 497 ; simple, and of sub
stance, their reality not necessary,
318 ; God has, and can communicate
them before creating their objects,
318 ; cannot demonstrate that ob
jects of, are without us, 319 ; simple,
can have real definition, 320; express
only possibilities, 325; are they arbi
trary ? 325 ; are in God eternally,
325 ; are in us before thought, 325 ;
not to be taken as actual thoughts
of men, 325, 326 ; influence of names
on, 328; physical, what regulates
their combination, 353, 354 ; generic,
do not follow models set in nature,
355 ; agreement or disagreement of,
four kinds according to Locke,
400; that of identity or diversity, '
400; that of relation, 400; that of
coexistence, 400 ; that of real ex
istence, 400; Locke's four kinds
reduced to two, 401 ; that of com
parison, 400, 401; that of concur
rence, 401 ; concurrence includes
coexistence and existence, 401 ; want
of, 439; of substances have neces
sary conformity to eternal arche
type, 446 ; what meant when said to
be true or false ? 452; general, may
be broken up ecthetically into par
ticular propositions, 464, 465 ; super
fluous expressions of, 483 ; wre may 1
not have real, yet know what we
are saying, 505; may be in us not
consciously, but availably, 505; do
not prove existence, 511; distinct,
our knowledge of, defective, 570;
their multitude perplexing, 570; not
enough for reasoning, 570 ; confused,
many lacking to men, 570; are
' images ' or ' impressions,' 570; give
rise to instincts, 570.
Ideas, complex, of three kinds, 5 ;
when clear, 266; their obscurity
rests on more than names, 268 :
may rest on presence in them of
ideas too few or too confused, 2(58 ;
may be clear and yet obscure, 272 :
something volitional in formation of,
276 ; how to avoid mistakes in form
ing, 276; of substance, when real,
277; of substance, when fantastical,
277 ; are not entirely without arche
type, 280; the combination of, not
wholly voluntary, 280 ; of a triangle
give a perfect idea, 280 ; which enter
into courage, 280; can they be com
posed of different simple ideas in
different minds, 313; can they be
regarded as arbitrary in formation,
325, 326 ; are they made by mind or
have they archetypes in eternal pos
sibility of things, 446.
Ideas, derivative, 21 ; are formed,
21.
Ideas, innate, what ? 4, 21 ; denied by
Locke, 4; at foundation of meta
physics and ethics, 11 ; the propo
sitions of arithmetic and geometry
are, 76.
Ideas, primitive, what? 15; distin
guished, 21; their reduction, 220:
some susceptible of further reduc
tion, 220; how they may be ar
ranged, 220.
Ideas, real : not necessarily conformed
to their foundations in nature, 275 ;
when possible, 275 ; simple ideas
are, 275 ; when complete, 278 ; when
incomplete, 278; simple complete,
278; adequate and inadequate, 278,
279; imperfect, give rise to many
and at present independent defini
tions, 279 ; of geometry, give per
fect ideas, 279.
Ideas, simple, 4; rudiments of knowl
edge, 119; which come to us by
one sense, 121 ; which come to us In
different senses, 129; those mosi
modified, 22;i; when clear, 265, 2(5(5:
all real, 275 ; mind passive in regard
to, 276; mind active in separating
them for consideration, 276 ; simple
only as regards us, 322; have little
subordination in line of predication
because of our ignorance, 323; only
INDEX A
795
in appearance, 323; our uncertainty
as to their incompatibility, 446.
Identical, propositions, not to be
despised, 18; maxim, the general,
83; propositions employed in logic,
406 : affirmations, their use exhib
ited in logical conversion, 409.
Identity, axiom of, a first principle, 13,
100; did it persist under the forms
of Euphorbus, the cock and Pythag
oras, in which forms the soul of
Pythagoras had been? 21,100; not
dependent on memory, 114 ; depends
on fact that future in each substance
is united to past, 115; or Diversity,
what is it ? 238; Locke's definition
of, 240; organization by itself not
enough for, 240; configuration by
itself not enough for, 240 ; the
monad essential to, 240; not in
bodies. 240 ; but in substance, 241 ;
in plants and animals it is depend
ent on souls 241 ; depends on soul or
spirit which constitutes the Ego in
thinking beings, 241, 242; depends
on vital union of body with soul,
241 ; not on fluent body, 242 ; not
upon certain atoms, 242 ; maintained
only by conservation of same soul,
242 ; is it affected by metempsychosis
of Pythagoras? 243; depends on
memory, 243 ; physical and real,
243, 246; moral and personal, 243,
245 ; founded on consciousness, 245 ;
something more than a mere pres
ervation of, needful to be called
" man," 245 ; apparent, to be distin
guished from real, 246; moral, con
stitutes a person capable of rewards
or punishments, 246; apparent im
plies real, 246: does not depend on
unbroken memories, 246, 247 ; pre
served by a middle bond of con
sciousness, 246; personal, proved
with utmost certainty by present
reflection, 247: personal, proved for
ordinary purposes by memory dur
ing interval, or testimony of others,
247; personal, absolutely dependent
on real identity, 247 ; personal, not
solely dependent on consciousness,
247: personal, rests on phenomenon
of self, 247; physical, rests on self,
247 ; can a breach of, occur in con
sciousness of same immaterial sub
stance ? 248 ; real, depends on bond
of perceptions, 250; moral, depends
on bond of apperceptions, 250.
Idiots, their defects, 146; compared
with madmen, 146; compared with
stupid persons, 146 ; imaginative
and well read, arrogate inspiration,
599.
Idol, the, of the day, always the great
est saint of paradise, 211.
Ignorance, falsely praised by some,
85 ; not always affected, 214 ; a
cause of false judgment, 214 ; a
knowledge of, desirable, 439; its
three principal causes, 439 ; a first
cause of, want of ideas, 439 ; a sec
ond cause of, inability to discover
connection between ideas, 439; a
third cause of, we do not follow the
ideas we have, 441 ; a despair of dis
tinct explanation favors continuance
of, 442 ; bad use of terms has helped
to maintain, 443; how a sin, 615.
Ilargus, its derivation, 302.
Illustrations, value of, 394.
Image, and idea, how they differ, 274 ;
clear, may consist with a confused
idea, 274.
Images, what? 182; come to us, 182;
not controllable, 182; distinguished
from exact ideas, 182; may arrest
182.
Imagination, 144, 145; not needful to
number or figure, 273.
Imagines majorum, 259.
Imbeciles, why regarded as men, 342.
Immediate truths, what ? 499.
Immortality, not a miraculous grace
from God, 53; of human soul dis
tinguished from incessability of ani
mal soul, 245; of human soul, 245,
246.
Impact of bodies, of the motion aris
ing from, 175, 176.
Impenetrability of bodies, 83 ; perfect,
125, 127.
Imperceptible bodies, 112.
Impetuosity of bodies, 123.
Impudence, 223.
796
LEIBNITZ'S CRITIQUE OF LOCKE
Impulsions between parts of matter,
differing views of, 54, 55.
Inability in some cases consistent with
guilt, 564.
Inattention, a cause of false judgment,
214.
Incessability of animal soul, 245, 246.
Inclination, how it passes into a prac
tical truth, 87.
Inclinations or propensions, how
formed, 201; various kinds, 201;
originate in soul, 202; beginning of
desire, 202 ; combated by contrary
inclinations, 203; combated by oc
cupations of another nature, 203.
" Incorporeal things," 329.
Index, an, in geometry, 625; its plan,
625; its use, 625; to science as a
whole, 625 ; to science as a whole
might be systematic, 625 ; to science
as a whole might be alphabetic, 625.
Indian, philosopher, his theory of how
the earth is supported, 226, 227.
Indices, ad torturam, 539; ad terren-
dum, 539; ad capturam, 539; ad
inquirendum, 539.
Indifference of will not essential to
freedom of will, 203, 204; not possi
ble, 171, 204 ; whence notion of, 205 ;
an absolute, an imperfection, 204,
205 ; the alleged, only apparent, 205 ;
dependent on a small prevalence,
205; is really only a capability of
being determined by least sensible
subjects, 205.
Individual, precise idea of, difficult to
discern, 310; absence of precise idea
of, shown in deception by persona
tion, 310; mathematical,^ 335, 336;
physical, 336.
Individuals, knowledge of, impossible,
309 ; something essential to, 331 ; of
one species never alike, 332.
Individual (proper) names; usually
given to ideas of substances, 361 ;
given occasionally to an accident,
361.
Individuality, includes infinity, 309.
Individuation, principle of, 239.
Inertia, 123.
Infants, why regarded as men, 314,
342, ar)0, 448 ; damnation of, held by
Augustine, rejected by the Scholas
tics, 594.
Infer, to, illustrated, 557.
Inference, 555.
Infinite, the, according to Locke, 12;
according to Leibnitz, 12; as posi
tive, 17; as composite, denied, 17;
not applicable to a whole, 154, 162,
163, 164 ; is it a mode or quantity ?
161 ; the number of things is, 161 ;
a number never is, 161, 163: syn-
categorematic, what ? 161 ; exists
only in the absolute, 162; idea of,
how applied to God, 162 ; not neces
sarily suggested by magnitude, 162 ;
not a modification, 162 ; arises from
consideration of similarity or the
same ratio, 162 ; completion of idea
of, comes from ourselves, 163 ;
source of notion, 163, 164; in in
tention, 163; in extension, 163; can
only be thought into original quali
ties, 163; space, no idea of, 163;
duration, in what sense a positive
idea of, possible, 164; divisibility,
gives no image, but an idea, 234, 275.
Infinites, our relation to, 51.
Infinitesimal, parts used only by ge
ometers 163 ; analysis (calculus)
unites geometry with physics, 440;
discovered by Leibnitz, 573 ; relieves
imagination , 574 : is superior to ge
ometry of Descartes, 574.
Inhesion, 62.
" Injustice, there is none where there
is no property," discussed, 433.
Innate ideas, truths, principles, max
ims, not to be used as a cloak for
idleness, 13, 72, 99; perceived less
easily than acquired or recollected,
20: difficulty in their perceptions
does not prove their non-existence,
20; occasions cause them to be seen,
do not bring them into being, 20;
defined, 21, 22, 74; not proved en
tirely by universal consent, 23, 71 ;
not proved by approval on presenta
tion, 23; sensations reminders of,
38 ; proof of, on internal grounds,
38; Locke repudiates, 38; none, 65;
not needed, 70: why Locke opposed
them, 71; often prejudices, 71; not
INDEX A
797
alone those confusedly known by
instinct, 74 ; truths are, yet we learn
them, 75; often suppressed as pre
mise in enthymeme, 77 ; external
" doctrine " stirs them up, 77 ; a con
sent among men sufficiently general
an " indication," not a demonstra
tion of, 77 ; their certitude comes
from what is in us, 77 ; are employed
without express consideration, 77 ; if
not known, do not cease to be innate,
77 ; recognized as soon as heard, 77 ;
at bottom known by all, 77 ; senses
not sufficient to show their necessity,
81 ; give the occasion and attention
required for their discovery, 81 ;
contain some of which we have not
thought and some of which \ve will
never think, 84; appear through
attention, 85 ; some, are not part of
natural light, 86 ; derivative truths
are, 88 ; formed by insight and in
stinct, 88.
Innate, practical principles, how ad
mitted by Locke, 87 ; principles and
innate truths distinguished. 88 ; prin
ciples, some moral rules are not, and
yet are innate truths, 88; compre
hend instinct, and natural light, 88,
92 : distinguished from natural light
as genus from species, 92; that men
violate the limits of justice no proof
that they are not, 92, 93; truth, not
known always and by all, 93; viola
tions of moral law, do not disprove
that it is, 93; ideas, are not at first
known clearly and distinctly as such,
94; require attention and method,
94; all not indubitably evident at
first, 94; can be asserted only of
necessary truths and instincts, 95:
influence of education on, 98; may
be obscured but not effaced, 98.
Innate truths, in what sense difficult
and profound sciences are, 76; dis
tinguish us from beasts, 77 ; can
both be known and also found by
mind, 80; principles and innate
truths distinguished, 88: idea of
God among, 94; idea of future life
among, 94; doctrine of, may lead to
assumption of infallibility, 96 : uni
versal consent to, not principal but
confirmatory proof, 96 ; can they be
effaced by education or custom ? 98 ;
why not more lustrous in children
and illiterates than in adults and
literati ? 98 ; may be obscured but
not effaced, 98; not creatures of
prejudice, 98; reduce to first prin
ciples, 99; "it is impossible for a
thing to be and not to be; " is this
among? 100; 'impossibility' and
'identity' among, 100; 'being,'
' possibility, and ' identity ' among,
100; ' whole is greater than its part,'
Locke denies its place among, 102 ;
' God should be worshipped ' among,
102; idea of virtue among, 104; are
they in mind as memories? 105 ;
defined, 105; may lead to laziness,
107 ; unravelled by discernment, 143.
Innocent, 262.
Innocents, 448.
Innovation, must guard against ambi
tion to make, 99.
Itisensibilia corpora, 3; ingredientia
perceptionum confusarum, 3.
Insensible perception, basis of relation
between sensible qualities, 50.
Instant, defined, 155.
Instinct, in ethics, 86; not always
practical , 87 ; its principles become
conclusions of natural light, 88 ;
its principles proved by reason, 88;
(le naturel) inclines custom to good
side, 90; establishes tradition of ex
istence of God, 90; gives affectionate
feeling between members of species,
90, 91 : what ? 391 ; even in man, .'591 .
Instincts, sometimes hard to distin
guish from customs, 96; their rea
son unknown, 99; reasons of, to be
sought, 107.
Intellection, what? 178.
" Intellectual System of Universe," 65.
Intention, 163.
Intentional species, 55, 381.
Interjection, says all in a word, 3(58.
Intuition, a certain knowledge by, 404 ;
primitive truths known by, 404.
Invention, 556.
Invenzione la pih vac/a, employed in
the spiritual world, 335.
798
LEIBNITZ'S CRITIQUE OF LOCKE
Invisible movement, 112.
Involuntary, defined, 177.
lo ti vedo, addressed by Italian to gal
lows, 92.
Irish, 29(5.
Isogon is in rectangle, 568.
John, St., fecit aurttm,6Q3.
" Journaux des Savans," 66, 421.
Joy defined, 171, 172; and felicity, 87;
and sadness, arise from prevalence
of pleasure or pain, 211.
Judgment, what? 143; distinguished
from mind, 144; false, 209; reasons
of, 214 ; Day of, 254.
Jure suo, qui utitur, nemini facit in-
juriam, 492.
Jurisconsults, bonmot of, 91 ; a rule of,
492; juramenta of, 538.
Jus accrescendi, 434.
Juvenal quoted, 91.
Kepler, 123, 551.
Kerkring, 345.
Knowledge, our present, best, 227, 228 ;
can go on to infinite, 228 ; of body, a j
perfect, perhaps possible, 228 ; em- [
pirical, how useful, 273; of truth,
what? 397, 400; a particular siguifi- |
cation of, 397; a general significa
tion of, 397, 398 ; confused perception
in empirical, 400; of hypothetical
truths, ideas in, 400; of truth, its
content, 400, 401 ; as actual and
habitual, 401 ; habitual, its employ
ment and improvement, 401, 402;
two sorts of. suggested, 402; intui
tive, 404, 410; demonstrative, what?
411; opinion, perhaps not, 417 : sen
sitive, 417, 419; sensitive, its certi
tude, 420; certain, 420; probable,
420 : clearness of, related to clear
ness of ideas, 423 ; extent of, 423 ;
not always intuitive, 423 ; not always
demonstrative, 423; sensitive, lim
ited, 423: sensitive, more limited
than ideas, 423 ; sensitive, can be ex
tended, 423, 424 ; in confused ideas,
424; its limits presented, 432; of real
existence, 439 ; difficulties in the way
of, 439, 440; of bodies and spirits,
441 ; have ideas for, 441 ; lack facts
for, 441 ; lack acnteness of senses
for, 441 ; though concerned entirely
with ideas may have certainty, 445 :
certainty of, suggested criteria of,
445 ; mathematical, real though
founded on ideas, 446 ; is of gen
eral or particular truths, 452 ; of
general truths best conceived by
help of words, 452; certainty of,
454; when self-evident, 464; order
of, 469; particular, or of facts dis
tinguished from universal and neces
sary, 470 ; appellations of, possibility
of their extension, 513; commences
in particular propositions? 517; em
ployment of mnemonic maxims in,
517 ; mnemonic maxims not formed
by induction, 518; what conduces to
the extension of, 527 ; mediate ideas,
their place in, 527; neither wholly
necessary, nor wholly voluntary,
528; divine, intuitive, 574; angelic
and beatified, 574.
KOivai HVVOLCLI, 43, 71.
Koran, 90,
Kuhlmann, Querin,601; on the Trin
ity, 601.
" L " employed to signify gentle move
ment, 300.
Labadists, 602.
Labbe, Father, his language, 293.
"Labyrinth, sive de compositione con-
tinui," 234.
Lsetitia and gaudiutn compared, 172.
Language, Locke on, 5; tropical use
of, must be guarded, 271, 272 : origi
nates in desire of being understood,
287; serves in reasoning, 287; of
tones, 287 ; place of general terms
in, 288; study of, reveals, not the
origin of ideas, but the history of
their discovery, 289; primitive root
of, 297 ; German likely the primi
tive? 298.
Languages, have altered, 294; have
common rootSj 297; Keltic, Latin,
and Greek, have common origin,
297 ; a primitive element in all, 298;
show the origin and migration of
nations, 303, 304; best mirrors of
human mind, 368; practical but not
precise, 370; same terms in, may
INDEX A
799
convey different ideas, 371 ; of world
will finally be reduced to grammar
and dictionary, 372 ; will be better
known with increase of knowledge
of mind, 372.
Lateran Council, 581.
Law of continuity, 50.
Law, divine, 262; natural, 262, 487;
positive, 262.
Law, civil, 262; of reputation, improp
erly so called, 262 ; described, 264 ; its
reformation needed, 2(54, 265 ; a pre
cept of wisdom or of the science of
happiness, 391.
Laws, three sorts, according to Locke,
261 .
Leander and Hero, 211.
Leaves, no two alike, 240.
Leeuwenhock, 346.
Legislator, not implied in all natural
rewards and punishments, 94.
Leibnitz, his sketch of Locke's Essay
in '• Monatliche Auszug," 7; hints
at a more complete reply, 7; delays
therein, 8; was to be in form of
dialogue, 9; unfinished, 9; his esti
mate of Locke's Essay, 10, 13; turns
to Theodicee, 10 ; Raspe publishes
reply, 10 ; differs from Locke as
Plato from Aristotle, 10 : thinks soul
not a "tabula rasa," but that it
has principles, 11 ; truth has other
foundations than experience, 11 ;
credits Locke with an approach to
his views, 11,45; regards bodies as
always in motion, 11: on axioms,
12 ; on logic, 12; on nominal and real
being, 12; on the Infinite, 12; his
explanation of Locke's aversion to
the doctrine that principles are born
with us, 13; his first principles, 13;
differs from Locke on the soul ever
thinking, 16 ; how he differentiates
his system from that of Locke, 42;
on German philology, 304.
Leibnitz's system, gives a new aspect
to interior of things, 6(5; unites
different schools, 66; explains union
of soul and body, 66 ; gives true
principle of things, 6(5; is simple,
66; is uniform, 66; explains laws of
nature, 66; how characterized, 68.
Leine, the river, whence its name, 300,
308.
Leipsic Acts, 266.
Lemma, what ? 413.
Lemnius, Levinus, his monster, 448.
Length, an idea of determinate, not
in mind, 149, 150; preserved only
by real measures, 150 ; pyramid to
serve as standard, 150; pendulum
measures, 150.
Lentulus, 308.
Lerins, Vincent de, 617.
Lessius, 153.
Lethargy, 166.
Liars who contradict themselves uni
versally obnoxious, 23, 77.
Licetus, 351.
Life, a good one preferable to a bad,
apart from eternal felicity, 217 ;
Epicurean doctrine, even apart from
felicity, not most reasonable, 217 ;
indefinite ideas of, 388; notion of,
is accompanied by perception in
the soul, 388; of man, that it should
be a dream, not impossible meta
physically, but rationally, 422 ; even
if a dream, does not deceive, since
its phenomena are in reliable series,
422.
Light, why referred to fire, 133: rel
ative to suitable organs, 133; like
sugar, 140 ; Aristotle's definition of,
321.
Light, internal, what ? 22,599; opposed
by perceptions of sense, 98 ; is source
of science, law, and morals, 98; its
struggle with perception of sense
described in Scripture and ancient
and modern philosophers, 98; dulled
by sense and custom, 98; — natural,
74.
Lights, first, 499.
Lignum nephriticum, 432.
Lingua Franca, 293; Zerga, 293.
Lion, known by claw, 357; its deriva
tion, 300, 301.
Lipenius, 62(5.
Livy, his accounts of battles imagi
nary, 543.
Locke, John, his Essay concerning
human understanding, 4; denies in
nate ideas, 4 ; declines reply
800
LEIBNITZ'S CRITIQUE OF LOCKE
nitz's criticism on his Essay, 6 ; on
axioms, 12; on logic, 12; on the
Infinite, 12 ; his change of view on
Newton's theory of gravitation, 12;
both assayer and transmitter, 19 ; in
his view of reflection relaxes his doc
trine about innate ideas, 45; denies
anything virtual in us, 46 ; believes
that mind does not always think,
47 ; his antagonism to innate princi
ples explained, 71.
Logic, its fruitfulness, 12; valuable,
18; full of truths which can only be
proved by innate principles, 44; a
natural, 88; has it helped to main
tain the obscurity of words, 378 ;
ignorance of, accounts for inaccurate
use of terms, 379 ; as much a demon
strative science as mathematics, 414 ;
of geometers but a part of general,
414 : of probabilities suggested, 541 :
chains of reasoning in, whence their
complexity, 561; laws of, principles
of good sense reduced to writing,
562 : a severe, not necessarily scho
lastic, needed in practical delibera
tions, 563 : because men reason
without artificial, does not prove its
inutility, 5G3; its scholastic forms
inconvenient, 504; have its rules
entire sway in probable questions?
505, 566; of the probable, Cardan
on, 566; a sublime, suggested, to
which common is but as alphabet,
566 ; its possible improvement, 566 ;
• Hooker upon its improvement, 566;
as a universal mathematics, 569 ; in
what particulars reason needs it,
570; not needed in intuitive knowl
edge, 574 ; what it comprises, 621 ; its
contents according to the ancients,
622; includes artes clicendi, 622; its
boundaries indefinite, 622; discur
sive, 623; medicinal, 624.
Logical form reveals force of argu
ment, 562.
Lombards, brothers of the, 449.
Lot, man's, a ground of praise rather
than complaint, 439.
Loubere, M. de la, 60.
Louis le Debonnaire, the oath of, 294.
Love, what? 167, 168; extension of
term, 168 ; of complacency, 108 ; of
benevolence, 168; disinterested, 168.
Lucan, a sally of his criticised, 144.
Lucian, his " True History," 399.
Ludolphe, 75.
Lully, Raymond, 590.
Lunafixa, 324.
Lune, its quadrature by Hippocrates,
527 ; axiom employed in its quadra
ture, 527.
Lutheran view of Eucharist, 611. 612.
Lutheranism, name disapproved, 544.
" Lux in Tenebris," 604.
Luz of the Rabbis, 242.
Lynx, its derivation, 301.
Lysimachia, 267.
Machine, its archetypes, 280.
Madmen, their defects, 146; from rev
erie, 166.
Magnetology, a science, 525.
Magnitude, 258.
Magots, 342, 343.
Mais, its equivalents in German, 366;
its derivation, 367; its elliptic use,
368.
Malotru, Abbot, 351
Man, should we call an irrational creat
ure in human form a ? 244 ; should we
call a parrot discoursing philosophi
cally a ? 244 ; requires not merely rea
soning soul, but something of figure
and constitution of body, 245: can
not be a machine, 246 ; a social being,
285; his speech the instrument and
bond of society, 285; how the name
is arrived at, 310; what creatures
may be so called. 342: definition of.
at once real and nominal, 342; no
rational animal has yet been found
with a body differing much from
that of, 351 : definitions of, Aris
totle's, 384 ; definitions of, Plato's,
384 ; a working definition of, 391, 392 ;
the most stupid, more rational than
the most spiritual beast, 552, 553 : ad
vantage of his position on the globe,
575.
Man-ness (Vhommelte}, 369.
" Mansions " applied to planets, 548.
Manual arts, their principles should be
taught by scholars, 628.
INDEX A
801
Marble, a veined block of, the .illus
tration of, 46, 76, 82, 84; block of,
with or without veins, 46.
Marcus Aurelius, 495.
Marian islanders, 101.
Marinas, 465.
Marionettes regarded as alive, 388.
Mariotte, M., an experiment of, 121 ;
on the color blue, 337.
Martin Corneille, his attempts to rec
oncile philosophy and religion, 581.
Masham, Lady, 65.
Mass, an image of substance, 219.
Materla priina, has impenetrability,
383 : has inertia, 383.
Mathematics, paralogisms of, faults of
form. 18: some propositions demon
strated outside of, 272, 414; not the
only science capable of demonstra
tion, 414 : why it has become so per
fectly demonstrative, 414.
Mathematicians, accused of passion
for glory, 93.
Matter, how regarded by Locke, 11,
16 ; how regarded by Leibnitz, 11, 16 ;
"medley of effects of surrounding
infinite,'' 51 ; is not rigid, 54; can it
think? 56, 59, 61, 62, 427: contro
versy with Bishop of Worcester
regarding, 56 ; distinct from exten
sion, 155: secondary, 231 ; primary,
possesses a perfect fluidity, 231 ; its
indivisibility, a perplexed notion,
234: distinct from body, 383: are
discussions concerning, as materia
prinia futile? 383; can it think,]
427 : primary, purely passive, and j
therefore incomplete, 428; primary, I
cannot produce perception, sensa- j
tion. reason, 428 ; secondary, a !
complete being, 428; secondary, aj
real mass, 428; secondary, supposes j
real unities, 428; secondary, its!
unities percipient, 428; secondary, |
constitutes an intelligible world of I
substances, 428 ; secondary, when !
God gives it organs for rational ex
pression He gives it immaterial
thinking substances, 428; second
ary, substances of, have within
them correspondence or harmony,
428 ; secondary, primitive powers of,
3r
are substances themselves, 428 ; sec
ondary, derivative, powers of, are
modes of being, 428 ; new hypothe
sis of, attributes to soul and body
only the modifications we experi
ence in ourselves and them, 430;
new hypothesis of, gives to our
ideas of matter greater regularity
and connection, 430; presents diffi
culty only to those who must im
agine what is only intelligible, 430;
changes in, dependent on reasons
incapable of arising from extension
and natures purely passive, 430;
changes in, cannot arise even from
particular and inferior active na
tures without the pure and univer
sal act of the superior substance,
430; not unintelligible, but in parts
not clear because of our confused
perceptions, which contain the infi
nite, and are the detailed expression
of what occurs in bodies, 431 ; can
not produce pleasure or pain, 431 ; if
susceptible of thought, may create,
501 ; if first eternal thinking being,
means an infinite number of think
ing beings, 506 ; cannot give rise to
perceptions, 507 ; not a monad or
unity, 507 ; a mass of an infinite
number of beings, 507 ; each being
of, is material or immaterial, 507 ;
has a General and Superior Cause,
507 ; under Pre-established Harmony,
507; all is, 518.
Maurier, his slanders on Grotius, 542.
Maurolycus, 442.
Maxims or Axioms, on what their self-
evidence rests, 462 ; are they evident
ex tpr minis, 462 ; demonstrated by
geometers, 462; when to be assumed,
464: their use, 473, 474; their intro
duction into public disputations,
477, 478, 479; formed through an
instinct, 481; bad use of , 482 ; help
ful to knowledge, 484, not to be
blamed for improper use of terms,
484 ; of special use in long processes
of reasoning, 485 ; how formed, 485 ;
use in mathematics, 485; use in
jurisprudence, 486; what included
under, 486 ; fundamental, 487 ; some-
802
LKIBMTZ'S CIUTIQL'K OF LOCKE
times employed out of season, 489;
identical, not nugatory, 490; their
use, 491 ; semi-identical, their use,
492 ; by many regarded as basis of
knowledge, 517 : relieve memory,
f>17; not arrived at by induction,
517 ; are present implicitly in exam
ples, 518: exist in minds of all men,
518: their certainty dependent on
comparison of ideas, 519: must not
be assumed gratis, 519 ; borrowed by
subaltern sciences from superior in
which they have been proved, 519:
accepted provisionally, 520.
Medicine, the antiquities of, important,
371, 372; improbability of a better
science of, 442; bad use of terms in,
448; well-detailed observations desir
able in, 489 : as an indicial term, (527.
Meditation, 166.
'' Meditationes de Coguitione, Veri-
tate, et Ideis," 3, 14.
J/«//M.S terinhiufi often sufficient, 481.
Megiddo, battle of. 547.
Meier, Gerard, philologist, 304.
Melanchthon, his views of Eucharist,
612.
" Memoires de Trevoux," 502.
Memory, and reminiscence, 77 : effects
of former impressions without, 106;
does not make same man. 114: after
a time may deceive, 248 ; immediate
and internal, cannot deceive, 248;
mediate and external, may, 248;
its fallibility, 403: an illustration
of, from keeping accounts of Hartz
mines, 403 : how Leibnitz applied
laws of, in keeping accounts, 403:
its functions, 513; its limitations,
514
Men, deprived of speech use other
general signs, 145 ; with tails, 341 ;
distribution of beard among, 341 ;
prefer to deceive and be deceived,
389. [545.
Menage, his abbot of Saint Martin, 350,
Mercures Galans, 438.
Me're, Chevalier de, his " Agreinens,"
539. [495.
Metaphysic, a real, being established,
Metaphysics, abstracts of, teach only
words, 493; the most general science
according to Aristotle, 495 ; ethics,
how related to, 495.
Metempsychosis, 53, 68.
Microscope, 227, 228; its use recom
mended, 553.
yiiKp6v, r6, not to be neglected, 51.
Milky Way, Democritus' correct sur
mise regarding, 277.
Mill, why unconscious of its continu
ous noise ? 47.
Mind, things may be in, of which one
is not always conscious, 20; may take
necessary ideas from itself, 78 ; has
more than mere passive capacity for
receiving impressions, 80; is not as
wax or tablet, 80; and judgment,
distinguished, 144: are its ideas of
itself no clearer than its ideas of
substance ? 226 ; the Supreme and
Universal, 516.
Miracles, not to be recurred to in ordi
nary way of nature, 55 ; accepted in
despite of analogy, 553; refused by
Christ, when ? 606.
Miraculous, its use in philosophy, 61.
Mirror, knowledge of its construction
as affecting rays of light, an illustra
tion of interior constitution of sub
stance and its relation to qualities,
458.
Misery, what? 200.
j Mixed, conclusion, 84 : modes, acquired
by observation, 222 ; modes, acquired
by invention, 222; modes, acquired
by explaining terms. 222 : modes,
acquired in dreaming and reverie,
222,223 ; modes, are they real? 329;
modes, do we always change species
of, with change of a constituent idea,
385.
Mixta imperfecte, 361.
Mode, a geometrical, may be referred
to specific essences, 386.
Modes, the, according to Locke, 5 ;
their kinds, 5 ; what ? 148 ; majority
of, not simple, 164; mixed, what?
221; how distinguished from ideas
of substance, 221; dependent on
mind, 276; must be possible and
compatible, 276: may be real acci
dents, 277 ; ingredients of, must be
compossible, 277 ; impossible, can be
INDEX A
803
invented, 280; if an idea in one of
them changed, it becomes another
thing, 385.
Modification and attribute distin
guished, 58.
Modifications which may belong nat
urally to a thing, 60.
Mola, .344.
Molyneux, his problem as to a man's
power of discriminating between a
cube and globe presented to him for
the first time after obtaining sight,
138, 139, 141; his Dioptric, 484.
Monad, defined, 147.
Monads, doctrine of, 101 ; substantial
unities, 231 ; not mass, 507 ; how the
soul acts in, 507; Bayle's objection
to theory of, 507 ; originate from
God and depend on Him, 511 ; the
"how in detail" incomprehensible,
511 ; their conservation a continual
creation, 511 ; doctrine of, evident
everyAvhere, 553.
" Monatliche, Auszug," 5; Leibnitz's
sketch of Locke's essay in, 7, 26-38.
Money, should not be debased, 578.
Monkeys, said to possess organs of
speech, 287.
Monster, is it a man? 314 ; can it be a
species midway between beast and
man, 447,448; his future state dis
cussed, 447, 448; possession of rea
son settles its manhood, 448; its
birth and shape presumptions of
its rationality, 448 ; we save it from
destruction during uncertainty, 449 ;
not made for nothing, 449.
Monsters, 344, 345, 346, 350, 351, 352;
their classification discussed, 339.
Montausier, 605.
Mood, one added to fourth figure, 561.
Moods, in each figure six, 560 ; four
common, what? 560; two added to
first figure, 5(50 ; two added to sec
ond figure, 561.
Moon, emperor of, his saying, 574.
Moral entities, their reality, 329; re
garded as " things " by jurisconsults,
329.
Moral, good, 260; evil, 260; sphere,
436.
Morality, truths of, demonstrable, 86 ;
laws of, their violation does not
disprove them to be innate, 93; ob
scured by excesses, 93 ; their neces
sity not demonstrated as it ought to
be, 93 ; its principal point God's so
cial connection with us, 247 : partly
founded in reason, partly in experi
ence and disposition, 392 ; " the New
Hypothesis" lays deep the founda
tions of, 433; consideration of goods
of life conduces to, 433 ; its questions
can be decided as incontestably as
those of mathematics, 433 ; diagrams
proposed in, 435 ; definitions invalu
able in, 435 ; algebra may help, 435 ;
Weigel's diagrams to illustrate, 435 ;
are its problems simpler than those
of geometry, 436? ideas of, are they
of human invention, 446 ; the proper
science of all men, 525.
More, Henry, 67: his " aerial vehi
cles," 380; his "Hylarchic princi
ple," 382.
Moses, 37.
Motion, in Aristotle, 174; by physical
impulse and by thought, is it con
ceivable in either instance ? 232 ; its
transference as an accident not con
ceivable, 232; amount of, lost in
impact of bodies, 232.
Motions, never lost, 24 ; become indis
tinguishable, 25; according to Aris
totle, 174, 320 ; real phenomena,
219: image of action, 219; motivity,
220; laws of, derived from a cause
superior to matter, 233; produced
by thought, no idea or experience
of, 233.
Motive, the present and the sensory
furnish a stronger, than the future
and reasonable, 92.
Mouton, 150.
Murder, its degrees employed to illus
trate how mixed modes change in
species with change of a constituent
idea, 385.
Musaeus, Jean, 590; "Use of Reason
in Theology," 587, 588.
Mussels, perception in, 142.
Name, why not given to murder of an
old man ? 222.
804
LEIBNITZ'S CRITIQUE OF LOCKE
Names, family, 258, 259 ; how bestowed
on tribes, 251) ; improper use of, gives
rise to confusion (obscurity) of
ideas, 268, 271 ; how they should be
employed, 271 ; a particular one for
each thing impossible, 307 ; such mul
tiplicity would baffle the end of lan
guage, 307 ; such multiplicity would
not extend our knowledge, 307 ;
proper, their use, 307 ; have usually
been appellations at first, 307 ; of
species, how given, 308; first used
by young children personal, 309;
their influence, 328; of substances
say more than definition, 393, 394.
Narquois, 293.
Nations, common origin of, 297.
Natural light, 36, 38, 8G, 88, 89, 92, 96,
597.
Naturally, or, "in the order of nat
ure," defined, 60, 61.
Nature, questioning, 18 ; makes no
leaps, 50: of things and of mind
agree, 74: labors to put herself
more at her ease, 194 ; a good econo
mist, 356 ; grand in effects, sparing
in causes, 356 ; proceeds by shortest j
paths, 484 ; its order, not of meta
physical necessity, 582 ; grounded in
good pleasure of God, 582 ; may de
viate therefore for superior reasons
of grace, 582.
Naude', 580.
Naudeana, 580.
Nebuchadnezzar, 545. [486.
Ne quis alterius damno fiat lucupletior,
Necessary, idea of, founded on pre- |
sumption of God's reasonable im
mutability, 180.
Necessary truth, when possible to j
prove, 3; what? 4, 326.
Necessitate inedii, 620 : Prsecepti, 620.
Necessity, never proved by experience,
22 ; when thought wanting, 182 : when
compulsion, 182 : when restraint, 182 ;
of geometrical and metaphysical con
sequences, 183 : does not enter into
physical and moral consequences,
183; opposed to contingency, 183:
not determination, 18:5.
Need, art of thinking in time of, 214.
Nicole, M., 617.
Nihll est in intellectu quod nonfuerit
in sensu excipe nisi ipse intellectus,
111.
Nisi, elliptic use of, 368.
Nisus, in Vergil, 598.
Nodus in scirpo, 460.
Nomenclator, 330 ; an illustrated,
printed at Nuremberg, 395.
Nominalists, 178, 623 ; seemed to make
nature seem stingy, 356.
Nominati, in Roman law, 360 ; age of
puberty, an example of, 360.
Non-appearance, not equivalent to
non-being, 98.
Non-consistence of bodies, 124.
Nothing cannot produce real being,
500, 501.
" Nothing in us but of what we have
been formerly conscious," 46.
Notion, what? 221, 222, 493; the true
mark of a clear and distinct, 227;
the word discussed, 329.
Notoriety, as evidence, 538.
" Nouveaux Essais," their origin, 5, (5.
" Nouvelles de la Republiqne des
Lettres," 50.
Novelle of Boiardo, 398.
NugatoriaB, 490.
Number, 220 ; knowledge of, not in
animals, 145 ; ideas precise in, 160 ;
has no minimum in extent, 160; col
lective idea in, 160; memory in, 1(50;
does not depend on imagination, 273 ;
short methods in, desirable, 570:
prime, how to recognize easily, 571.
" Number, The great," argument from,
617.
Gates, 65.
Oath cannot fix opinion, though it may
teaching, 619.
Obediential power, 428.
Obreptlon, 276.
Occam, 588.
Occult qualities, 63, 204, 431.
Ocker, 302, 308. -
(Ecumenical councils preserved from
error as to doctrine, 618.
Old man of the mountain, 196.
Oldenbnrgh, 52(5 ; Count of, 259.
"One and one make two," a defini
tion, not an axiom, 23.
INDEX A
805
" One and two are three," 471.
Opal, 432.
Opinion, the perception of a truth, 92;
natural, the perception of an innate
truth, 92; its value in support of
truth, 530; freedom of, what? 537;
how acquired, 556.
Opinions, voluntary indirectly, 528 ;
theoretic, their practical influence,
535; how they spread, 535.
Opposition, between the individual and
the public an evil, 620; between
sects, an evil, 020; often an accident
of party rather than result of rea
soned conviction, 620.
" Opposite angles made by intersec
tion of two straight lines an equal " :
is this truth innate ? 105.
Optics, may be learned by the blind,
140 : founded on maxim that nature
proceeds by the shortest paths, 484.
Oracles, internal, derived from early
education, 611.
Orel f/alea, 479.
Order, tempore vel natura, 82 ; of analy
sis, different from that of occasion,
220 : the natural distinguished from
the historical, 470.
Orders of Rome, have narrower rules
than their Church, 619.
Origin of ideas, not preliminary in
philosophy, 15.
Ostensives, the, 491.
Ostracism, 222.
Otfried, gospel of, 294.
Ourang-outang, man may become as
stupid as, yet preserve rational soul,
244 : illustrative of human form
without human soul, 244.
Outlines, impression on empty tablets
of mind, a thing of self-perception,
20.
Oyster, perception in, 142; tossed by
monkey, an illustration, 491.
Pain, and pin, relation between, 133;
why referred to body ? 133 ; rudi
ments of, their place in our welfare,
170, 171 ; includes apperception, 194;
partly unconscious, 195 ; what ? 200 ;
a feeling of imperfection, 201.
Painting, deceives by metonymy and
metaphor, 137 ; in fresco, some good
things like, 173; a, which was only
intelligible when looked at through
a cylindrical mirror, 269.
Pajon, 595.
Pallium, 394.
Pandects, 296, 415 ; similarity of style
among authors far separated in time,
416.
Pappus, 573 ; on analysis, 521, 565.
Parabola, how one may add to his idea
of, without changing its concealed
constitution, 386.
Parallel lines, their definitions, 318.
Paralogisms often dependent on as
sumptions, 481.
Paralytic, could learn geometry, 139.
Parrhesia, Tra.ppijo'ia, 223.
Parricide as a possible crime, 325.
Parrot who talked philosophy, would
it be a parrot ? 244.
Parrots, possess words without organs
of speech, 287.
Partes extra partes, 163.
Particles, what? 364; their use, 364;
not absolutely necessary, 364 ; their
explanation, 366, 367 ; may connect
parts of an idea, 364; should be in
vestigated, 368; catalogues of, 365;
concealed in inflections of nouns and
verbs, 365 ; best explained by para
phrase, 367 ; by ellipsis equal to com
plete sentiment, 368.
Particular propositions appear as uni
versal affirmations, 568.
Pascal, on calculations of chances,
539.
Passah, Hebrew, 361.
Passion, how controlled, 207; or pas
sive power discussed, 218 : towards
imperfection, 219; when it is con
fused, a step towards pain, 219.
Passions, whence ? 167; what ? 172 : af
fect body, 173 : can be mastered, 207 ;
their illogical influence, 614, 615.
" Pater, space of," 578.
" Patience, forced," of soul, 496.
Paul, St., 43, 153.
Paulus, jurisconsult, his rule, 486.
Pearls of Slusius, geometric figures
about which much was known before
they were found to be cubic parabo-
806
LEIBNITZ'S CRITIQUE OF LOCKE
loids, 387 ; or the lines of the cubic
parabola, 465.
Peas, throwing, against pins, 208.
Pelisson, 591, 592.
Pendulum, employed to measure
length, 150, 156; called in German,
" unruhe," 171.
Peun, 602.
Pensees colantes, 182.
Perceptions, exist too feeble to be re
membered : illustration of, 24 ; if we
did not always have, could not be
waked from sleep, 24 ; illustration of
man waked by several voices, not by
one, 24: never lost, 25: become in
distinguishable by composition, 28;
without apperception infinite, 47 :
reasons why we may not be conscious
of, 47, 48; insensible, their efficacy,
form images of qualities, 48 : con
nect each being with rest of uni
verse, 48 : make present big with
future, and laden with past, 48:
insensible, explain Pre-established
Harmony, 49 ; insensible, render
death a sleep, 49: insensible, con
stitute sameness of individual, 49;
insensible, their determining influ
ence, 49 ; and objects, their relations
not arbitrary, 50; insensible, give
rise to noticeable perceptions, 50:
insensible, of use in pneumatology,
50; insensible, explain why souls are
never perfectly alike, 50, 52 : not
perceived or remembered, known
only by consequences, 112: have
them while asleep, 112: minute,
mental, though not perceptible,
have effects, 116 : unpremeditated
actions, result of minute, 116 : thence
customs, 116; thence passions, 116:
these in morals, what corpuscles are
in physics, 11(5 ; prevent indifference
in moral actions, 116; incline with
out necessitating, 116; of which not
conscious, 121, 135: defined, 135;
animals have, 135; have wre, uncon
sciously? 135; mind passive in, 135:
Locke denies unconscious, 136; in
plants, 141, 142 ; of images, 142, 143 :
feeble, in oyster and mussel, 142 :
never without minute, 166; none
indifferent to us, 167 ; confused,
advantages of, 170 ; perceptible
only in mass, 199; pertain to all
the entelechies, 218; in enthusiast,
597.
Perfection, man's highest, in search
for true happiness, 206.
Perfections, certain, bring greater im
perfections, 208, 209.
Peripatetics, 65 ; obscure, 378 ; on rare
faction and condensation, 124: their
ten predicaments, 380.
Perpetual mechanical movement, il
lustration of an "apparent idea,"
505.
Persians, doubts about the history of
the, 545.
Persius quoted, 272.
Person, its content according to Locke,
245.
Persons, can there be two with same
immaterial substance? 248.
Peruvians, their cruelty, 89.
Petronius, " culolescentes in scholis
stultissimos fieri,1' 482.
Plunedo, Plato's, 170.
Phantasms, 459; sensitive, 459; good
term for "secondary qualities" or
"sensitive ideas," 459; confused,
cannot abide if distinguished into
ingredients, 459.
Phantoms of sense opposed to pure
ideas, 78.
Pharsalia I, 128, 144.
Philalethes, why the name was as
sumed, 69.
Philanthropy defined, 91.
Philology, 372.
" Philosophia Mosaica," 63.
Philosophy, practical, 621 ; as an indi
cia! term, 627 ; introductory to other
divisions, 628.
<t»opd, its signification, 321.
Photis (Fotis) and the golden ass, 243.
Physical laws, as to God, not neces
sary, 183.
Physicist, 525.
Physics, as a whole, will never be a
perfect science, 525 : some parts of,
scientifically detailed, 525; cannot
give a reason for all experiments in,
525; its content, 621.
INDEX A
807
Piety, practical, 520; natural, does it
save? 590,591.
Pin, and pain, 133; affrights, 283.
Pineapple, cannot experience its taste
by account, 321; its cultivation, 322.
Pisani, Ottavio, his "Lycurgus," 283.
Piso, 308.
Place, what? 152; particular, 152;
universal, 152 ; if nothing fixed,
could yet be determined, 152 ; an
order of coexistences, 229.
Planetary communication, complica
tions connected with, 343.
Plants, fecundation in, 338.
Plato, 392; supposed to believe that
soul has originally principles or
ideas, 42, 43 ; his idea of matter, 66 ;
his " Meno," 78; on conscience, 91;
his " Phjedo," 170.
Platonist, his soul of world, 380, 382 ;
his reminiscence refuted, 105.
Pleasure, how founded ? on semi-
pleasures, 170; on semi-pains, 170;
a step to happiness, 200 ; its low
est degree, 201); its most estimable
kind, 200; what? 200, 201; feeling
and appetite carry to, 201 ; can grow
infinitely, 201 ; cannot have a nomi
nal definition, 201; allows a causal
definition, 201; and happiness dis
tinguished, 207; a feeling of perfec
tion, 200, 201, 208; or displeasure
accompanying an action can be I
changed, 216 ; good, of God, defined,
431 ; cum ratione insanire, an ele
ment in, 459.
Pleasure and pain, 167-173 : not capable
of nominal definition, 167 ; affinity
of, 170; pertain only to mind, 200;
originate in mind and body, 200,
202 ; not in matter but in soul, 430.
Pleasures, luminous, how they improve
us, 207 ; confused, the danger of, 207 ;
two cannot be enjoyed at once, 210;
can they be enjoyed with pain ? 211 ;
do men diminish future? 212.
Plenum, unnecessary hypothesis, 54;
uses of, 54.
Pliny, on Democritus, 66.
Plus videitt oculi qiiam oculus, 617.
Pluto, his helmet, 479.
Pneumatics, doctrine of spirit, 362.
Pneumatology, 52.
Point, defined, 156.
Polemo, " the world is God," 518.
Police, a better, desired, 438, 526.
Pollen, 338, 347.
Polygon, to illustrate relations, 236.
Poniatovia, prophet, 604.
Portugal, Sea of, 134.
Possible, 'distinctly intelligible,' 277.
Power, idea of, how formed, 130, 174;
possibility of change, 174; active,
may be called force, 174 ; active, the
proper attribute of spirit, 174, 233;
passive, as mobility and resistance,
174, 175 ; passive, that of bodies,
174, 177, 233; a simple idea through
ignorance, 175 ; relation of, 175 ;
active, idea of, furnished by reflec
tion, 175, 177 ; an obscure idea of,
given by an impinging body, 176 ; its
noblest sense, 176 ; active, in entele-
chies alone, 177 ; liberty the most
important form of, 218 ; what ? 224 ;
includes tendency, 224 ; an entelechy,
224.
Powers, pure, are fictions, 110; real,
not possibilities, 112 ; have tendency,
112.
Prretor's album, 44, 86.
Predicaments, 361 ; use of, important,
311, 380; the ten, of the Peripatetics,
380; may be reduced, 380.
Predicate is in subject, 568, 569.
Pre-established Harmony, 49, 230,
233, 252, 333, 421 ; requires sensible
outlines, 78: explains motion of
bodies, 229 ; its influence on theology
and pneumatology, 363.
Pre-judgments, by which men would
except themselves from discussion,
531 ; legitimate in the Romish con
troversy, 531.
Prejudice. 98, 99. [364.
Prepositions, their use and origin, 290,
Prescriptions of Tertullian, 531.
Presentiments, we have, 15.
Presumptions, what? 260; of the juris
consults, 538, 616.
Primary matter, 231.
Primitive language, see Language.
Primitive truths cannot be proved by
anything more certain, 410.
808
LEIBNITZ'S CRITIQUE OF LOCKE
"• Prince, a great," as benefactor of
the race, expected by Leibnitz, 438,
629.
Principium individucttionis, 239.
Principle of principles : union of
definitions by means of identical
axioms, 521.
Principles, first, according to Leibnitz,
18 ; on which men agree, 71 ; not im
pressions which minds receive with
their existence, 71 ; universal con
sent does not prove them innate, 71 ;
not universal, 71 ; the two great
speculative, 77 ; first, how arrived
at, 99; should be open to judicious
investigation, 108, 473.
Probabilities, mathematical calcula
tion of, 539; illustrated, 540, 541;
a new logic of, 541 ; methods of es
caping unpleasant, G14, 615.
Probability, the part of logic which
estimates, still wanting, 213 ; Aris
totle's mistake concerning, 214; its
consideration important yet neg
lected , 417 ; degrees of resem
blance (ex datis) can be determined,
417; teaching of Jesuit moralists
concerning, 418 ; must be drawn
from the nature of things, 419;
opinions of persons collateral only
to its determination, 419; opinion
of Copernicus, though he was alone,
had most, 419; art of estimating,
more useful than most demonstra
tive sciences, 419; grounds of, 529.
530, 532; its highest degree, 538;
nature of, 529, 585 ; false measures
of, in what they consist, 611 ; one can
not lean to side of less, 615.
Probable reasoning of jurisconsults,
577.
Problems, what? 411.
Proclus, 108, 463, 491 ; demonstrates
axioms, 14; his philosophical style,
41(5.
Procopius, when credible, 542.
" Proferendis, De, scientise denion-
strandi pomoeriis," 437.
Progress, in all things, 142 ; to be ex
pected, 440, 629.
Progymnasmata, 399.
Projection, of a circle on a plane, illus
trative of relation between idea and
its cause, 133.
Prolepsis, of Stoics, 43.
Proof, advantage of continued appli
cation of, 402, 403; complete, 538;
more than complete, 538 ; more than
half complete, 538; less than half
complete, 538 ; slender, should it in
criminal charges be in any case ac
cepted against a man? 577 ; slender,
accepted against a man not to con
demn him, but to prevent him doing
harm, 577.
Proofs, 411.
Propositions, which secure acquies
cence as soon as heard, are they
found in physics as well as mathe
matics? 83; identical, do not admit
proof, 83; universal, of the truth or
certitude of, 452; being certain of,
454 ; can they be obtained by expe
rience of "consequences in a con
stant manner " ? 461 ; express as
late an effort of mind as formulat
ing axioms, 470 ; general, concerning
substance, are often trifling, 493;
some grand and beautiful, 494; uni
versal, do not relate to existence,
498; universal, may be accidental,
498 : a division of, into general and
particular, virtually a division into
those of fact and those of reason,
514 ; capable of a certain generality,
514; of reason, 515 ; mixed, 515 ; how
far general and certain, 515; cate
gorical and hypothetical, how re
lated, 515, 516; of two kinds: of
fact, 537 ; of speculation, 537.
Propensities, insensible perceptions of
perfections and imperfections, 201.
Proper names, originally appellatives,
307.
Property, term discussed, 433, 434.
Prophecies, instances of pretended,
604; their bad effects, 605; alleged,
said to have had" a good effect, 606.
Proportion, the relation of, 258.
Propriety, regard for, among men, 91.
Proscriptio, 222.
Frosthaphseresis, in probability, 540;
how employed by peasantry, 540.
Protestants, non-opinionative, may be
INDEX A
809
saved, according to some Romish
doctors, 591.
Proverbs, 481.
Psittacism, 191, 196.
Public, opinion, its force, 262; spirit
depends on morality and religion,
536.
" Public spirits," 536.
Puccius, Franciscus, 593.
Puffendorf, 435.
Punishment, 260.
Pyramid, conservation of measure by,
150.
Pyrenees, 308.
Pythagoras, 100, 474.
" Quaken," as a stem, 298.
QUSB uno spiritu continentur, 241.
Quakers, 599.
Qualities of things, defined, 131 ; pri
mary, what? 131; secondary, what ?
132 : power, when regarded among
the primary, 132; power, when re
garded among the secondary, 132;
secondary, their relations to corre
sponding ideas, 133; even primary,
do not appear uniformly, 134 ; clas
sified upon basis of most common
conditions, 134; real, what? 134;
what? 148; sensible, confused, 432;
sensible connections known only
through experience, 432; analysis
employed in, 432; secondary (sensi
tive ideas), their relation to interior
constitution of bodies, a confused re
sultant of the actions of bodies upon
us, 458.
Quarto moclo, properties in, how appli
cable to inftma species, 455.
"Quek,"299.
Questions, are themes between ideas
and propositions, 398.
Qtiia inter omnes homines, etc., 91.
Quietists, " bad," 53; " idle," 526.
Quinquina, 525.
Quodlibets, 419.
" R," employed to signify a violent
movement and noise, 299.
Rabbinage, 372.
Ragosky impelled to attack Poland,
604.
Raiiiists, 398.
Ram us, Peter, on the reduction of logi
cal figures, 408, 409.
Rank, of man in scale of being, 439 :
carries with it requirements, 609,
610.
Rarefaction, of matter, 124; none,
127.
Raspe, publisher of " Nouveaux Es-
sais," 10.
^Rauschen," defined, 299.
Realists seem to make nature prodigal,
178, 356.
Reality, what? 22, 148; of relations
depends not merely on the minds of
men but on that of God, 276, 277 : of
the nominal definition, 316; of our
knowledge, 444.
Reason, natural revelation, 32; essen
tial to all revelation, 32 ; its place
in investigating an alleged revela
tion, 36; of men, 69; animals have,
145 ; prefers to consecrate term
to man, 146: to declaim against,
foolish, 206; "a concatenation of
truths," 206; consists in knowing
the truth and following the good,
206 ; depends on characters, 220 ;
Leibnitz's definition of, 555 ; Locke's
definition of, 555; a special defini
tion of, 555 ; its uses as defined, 555 ;
a priori, 556; in truths corresponds
to cause in things, 556; confined
to man, 556; apparent in animals,
what? 556; its two parts, 556; its
four degrees, 556 ; one of these not
apparent, 556; contrary to, when?
578; above, when? 578, 579; things
beyond our present faculties not
above, 578, 579 ; not opposed to faith,
580; defined, 583; used by all as
long as it seems to aid them, 583;
in theology agitated between Socin-
iaus and Catholics, 585 ; and custom,
difficult to satisfy both, 609.
Reasoning, an oddness in some people
due to a non-natural connection of
ideas, 282; what? 411; all, springs
from things already known and
agreed to, 413; is ex prsRcognitis
etprsecoiicessis,±13,47Q; claims of,
an infinite number of, 561.
810
LEIBNITZ'S CRITIQUE OF LOCKE
Recalling absent ideas, an active
power, 219.
Receptivity, 174.
Recollection, its two meanings, 165.
Reduction, of figures in logic best ef
fected by principle of contradiction,
407.
Reflection, according to Locke, 4; " a
regard for what is in us, and born
in us," 11, 45; more than Locke
makes it, reaches mind, 23, 24, 45,
75, 82; where Locke approaches
nearest Leibnitz, 111 ; senses furnish
material for, 220.
Regula, no» ex, jus suiiti, $ed ex jure
quod est regulcim fieri, maxim of
Paulas, 4S!6.
Keinesius, 372.
Relatct, 235.
Relations, a complex idea according to
Locke, 5 ; of comparison, 144 ; of con
currence, 144 ; subjects of , 235 ; have
something of essence of reason, 235 ;
have foundations in things, 235 ; come
from supreme reason, 235 ; may
change, without change of subject,
235 : ideas of, their clearness, 236 ;
of proportion, 258 ; of imperfect
magnitude, 258; of origin, 258; of
the family, 258; of consanguinity,
259; alliance, 259; affinity, 259; nat
ural and moral, 260 ; by institution,
260 ; itself often clearer than it's
ground, 2(55 ; value of knowing
ground of, 265 ; dependent on Divine
Mind, 277 ; knowledge of, largest
field of human investigation, 432.
Relative terms, what ? 235, 236 ; which
are usually deemed positives, 237.
Religion demands unambiguous words,
379.
Remembrance, what? (sub-venire), 77,
165.
Reminiscence, 15, 20, 77, 107 : of Plato,
15, 46; of what we know sometimes
difficult, 20 ; Plato's doctrine of, de
nied, 21, 7!), 80; how distinguished |
from other forms of thinking, 105.
Resemblances, possibilities in, 356.
Resistance in matter, is it invinci- !
ble? 122; arises in different ways, |
122, 123; denned, 122; comes from i
inertia, 123 ; comes from impetuos
ity of body, 123 ; comes from adhe
sion, 123.
Resolutions, should be made when
a man is in the midst of good im
pulses, 192; should be kept when
their sensible reasons are only surd
thoughts, 196.
| Respondentes, 478, 479.
j Rest, its privative nature discussed,
131 ; cause of, 131.
I Restraint, what ? 182.
Restitutio in integrum, 534.
Retention, a faculty of mind in con
templation, 142; in memory, 142,
143.
Revelation, what? 32; must be sure
concerning, 554; original, 584; tra
ditional, 584 ; cannot go against clear
evidence of reason, 584; cannot be
received against intuitive knowl
edge, 584 ; determines against prob
ability, 585; supernatural reason,
596 ; had external signs, 597 ; God
sometimes illumines mind in, 597 ;
defined, 598; judged by reason and
Scripture, 598.
Reveries, 165, 166.
Reversal of viscera, 352.
Revolution, a general, said to be im
minent through the spread of loose
opinions, 536 ; will be a punishment
and yet an advantage, 536.
Reward, 260.
Rhetoric, not truthful or calm, 389;
though fallacious, popular, 389; cer
tain ornaments of, wisely employed,
390.
Rhine, 308.
Richard First of England, exonerated
from charge of murder by Old Man
of the Mountain, 197.
River changes its waters, yet is same
river, 240.
Rivers, their names, 308.
Roberval, at eighty publishes his geom
etry, 463; his work on Euclid's ele
ments, 107, 473.
Rod and sugar illustration, 470.
Rohaut on motion, 233.
Romans ii. 15, quoted, 43 ; 14 : 4, quoted,
447.
INDEX A
811
Romans who built, 99 ; excelled Greeks
in law and arms, 415.
Romulus, doubts about, 545.
" Rorarius," (JO.
Rothwelsch, its nature, 292.
Round, why distant things seem so,
120.
Rue-tit i* Acervl, problem of, 328.
Ruhr, 308.
Rules, sure when established on reason,
45: good, their division, 486; when
universal, 487; of jurisprudence,
their uses, 493.
Sagacity, 411, 555.
Sancho Paiiza, saw Dulciuea by hear
say, 321.
Sarmatian, 297 ; salt pits, 696.
Satires, as historical material, 542.
Satisfaction influences will, 188.
Saxons, ancient books of, 295.
Scaliger, Joseph, writes against math
ematicians, 93; Julius, his semina
seternitatis, 43; dream of, 106.
Scandiano, Count of, 398.
Scarlet, like sound of trumpet, 128,
321.
Sceptics, 6G, 420, 422.
Scheubelins, his edition of Euclid, 403.
Schilter, 295, 304.
Schoenberg, 100.
Scholastics, 55, 02, 60, 428, 503, 511 ; the
question of immortality among, 52 ;
their attempts at definition ridiculed
by Locke, 320; sometimes present
discussions of value, 494 : their de
constantia subjccti, 51(5; abandoned
infant damnation, 594.
Science, demonstrative, founded on
innate knowledge, 79 : its content,
320 : historical, its content, 326 ; each
has its prfKcogtuta, 517 ; divided into
three kinds, 621 : each division may
be made to absorb the others, 622;
Nominalists on, 623; one for each
truth, 623; like ocean, arbitrarily
divided, 623; truths may be placed
in different divisions, 623 ; a twofold
division proposed, 623; a synthetic
and practical part of, 624; an ana
lytic and practical part of, 624 : how
the ancient triple division should be
understood, 625; civil division of,
626 : a third division, an index, pro
posed, 625.
Scipio Ferreus, 571.
Scriptures, Holy, may the literal sense
of, ever be abandoned ? 589.
Scythians, 297.
Sea, noises of, as an illustration of in
sensible perceptions, 15, 48.
" Search after Truth, The," 176.
Seckendorf, nature of his work, 543,
544.
Secondary matter, not of utmost
subtlety, 231 ; unity in, from con-
spirant movements, 231 ; doctrine of
monads throws much light upon, 231 .
Secondary qualities, can any neces
sary coexistence or incompatibility
between them be known with cer
tainty? 461.
Sectarianism, its strange influence,
618.
Self, dwells in us, 246 : basis of phys
ical identities, 247 ; to be distin
guished from phenomenon of self
and pure consciousness, 247 ; phe
nomenon of, basis of personal iden
tity, 247.
Semicircle, a centre of magnitude of,
cannot be, 354.
Semina seternitatis, 43.
Semi-identicals, 492.
Semi-pains, 170.
Semi-pleasures, 170.
Sendomir, Council of, 612.
Sennertus, 487-489.
Sensations, what? according to Locke,
4 : reminder of innate truths rather
than proofs, 38; carried by nerves
to brain, 121 ; how received by nerves
or membranes, 122; different, pro
duced by same object, 133; what?
165 : of light, its genesis, 171 ; of
heat, its genesis, 171 : action in,
220 ; and imagination, difference
between, 419, 422 ; may be same
species with imagination, 422 ; give
certainty, 511 ; scepticism regard
ing, impossible, 511; are "percep
tions of sensible things," 511; arise
from external cause, 511, 512; jus
tify mathematical demonstrations.
812
LEIBNITZ'S CRITIQUE OF LOCKE
512; of the different organs bear
witness to each other, 512 ; beyond
these, no knowledge but probabil
ity, 512.
Sense-qualities, capable of real defini
tion, 17; give occasion to perceive
ideas and truths, 82 ; not of arbi
trary constitution, 171.
Senses, some ideas not from, 70; give
confused ideas and truths, 82 ; do
not give truths absolutely certain,
470; are liable to illusion, 470.
Sensible, qualities, pleonasm of per
ception in regard to, 324 ; species,
381.
Sentiments and beautiful sentences of
authors, their use, 492.
Sereuns, 4(35.
Series, a continued, to what extent
in corporeal and intelligent worlds,
332-334; certain, not compossible in
universe, 334.
Series, infinite, 424 ; expressive of pro
portion of square and circle, 425;
can it be expressed in a finite quan
tity, 425 ; a, of syllogisms, 564.
Sextus Pomponius, 241.
Shadows interpenetrate, yet are dis
tinct, 238.
Shame, what? 173.
" Shepherd, The Extravagant," 389.
Siam, King of, and existence of ice,
530, 582.
Sibyl, Cumaean, 598.
Si f rid, Petri, 546.
Sight, object of, may not be in ex
istence when seen, 137 ; educated,
of physicians, 392: neither wholly
necessary, nor wholly voluntary,
528.
Signs, 621 ; and indications, medical,
539.
Simple ideas, 4 ; simple in appear
ance, 120 ; apperception does not
divide them, 120; analyzed by rea
son, 121 ; which come by one sense
only, 121 : arranged according to
means by which we perceive them,
121 ; cannot have nominal defini
tions, 319.
Simple modes, 164.
Sins and duties, 261.
Size, knowledge of, howr acquired, 160.
Sleep, 165, 166 ; does not arrest percep
tion, 112; if soul exist in, without
perception, why not thought exist
without perception ? 113; secured by
division of attention, 115; dream
less, has a feeble consciousness,
115.
Sleidan, his forgetfulness, 114 ; Charles
Fifth's opinion of, 543 ; nature of his
work, 543.
Slusius, his "pearls," 387, 465.
Society, founded in nature and con
venience, 285, 286; not founded, as
according to Hobbes, in the wicked
ness of the species, 285, 286.
Socinians, 586, 589.
Socrates, 495; in " Meno," 78: on
affinity of pleasure and pain, 170;
his demon, 598.
Solem clicere falsum ctuclet, 156.
Solidity, 220: how caused, 122: im
penetrability, a synonyme, 122, 123;
sensible, 124; essential, what? 124;
what? 125; perfect, an experiment
regarding, 126.
Solomon, quoted, 158.
Solon, on parricide, 325.
Something, the Eternal, is it a being,
501.
Sondern, its meaning, 366.
Sophia of Russia, 601.
Sophists, their obscurity of teaching
ridiculed by Lucian, 378.
Sorbonne, Casaubon's bon-mot con
cerning, 478.
Sorites, 559, 561.
Sorrow, what? 172.
Soul, in it a multitude of impressions,
inarticulate like noise of waves, 11 :
always thinks, 11 : more independent
than thought, 15, 24: its thoughts
not always distinct enough for re
membrance, 24; if passive, is with
out life, 25 ; its immortality not de
pendent on gracious miracle, 25, 53,
63; its alleged reunion with ocean
of Divinity, 53: its ineffaceable con
nection with organic body, 53; its
immortality proved, 62; can it be
annihilated? 62: the importance of
its immateriality to religion and
INDEX A
813
morality, 62, 63: Locke's view of
its immateriality, 63 : our thoughts
and acts come from its depths,
70 ; is its failure to perceive only
a failure to remember what was
learned formerly? 79; can a thing
be in, and yet not known when
the soul has the capacity of know
ing it? 79; may not nature have
concealed therein some original
knowledge? 79; its properties and
affections cannot be all considered
at once, 79 ; may have possessions of
which we have made no use, 80; has
more than naked faculty towards in
nate truths, 81 ; has dispositions, ap
titudes, propensities toward innate
truths, 81; nothing in, which will
not be expressed by understanding,
87 ; what it comprises, 111 ; never
without perception, 112; continuity
of its perceptions not disproved by
dreamless men, 115; of child, what
ideas in, before or at moment of un
ion with body, 117 : its thoughts indis
tinct when a multitude of movements
in brain, 117 : it always expresses a
body which is always impressed in
an infinite multitude of ways, 117 ;
perception in, of which it is not con
scious, 117; does not require that
impressions be of a certain form and
size to be perceived, 117 ; movements
within, correspondent to circulatory
and digestive movements in the
body, 117 ; how do we know it al
ways thinks, 117: what is perceiva
ble is composed of what is not so,
118; is to say that it thinks without
consciousness, to say that it thinks
unintelligibly? 118; not merely the,
always thinks, but the man, 118 ;
passive only in perception of simple
ideas, 119; active in forming com
plex ideas, 119 ; impossible for it to
think expressly upon all its thoughts,
119 ; if thinking on all its thoughts,
it would never pass to a new thought,
119; its connection with body, 138;
vegetable, 141 ; a simple substance
or monad, 147 ; while representing
body, preserves its own perfections, i
181 ; dependent on body, 181 ; in
voluntary acts body dependent met
aphysically on it, 182; a living
mirror, 219 ; a " separate,' ' inconceiv
able, 220, 221 ; thinks and feels al
ways, 230 ; never leaves entirely and
at once the body, 230; in animals
and vegetables secures their iden
tity, 241 ; cannot wholly leave body,
242; keeps even in death an organ
ized body part of preceding, 242;
basis of identity, 242; no transmi
gration of, but transformation, 242;
should doctrine of its immaterial
ity be received on faith? 429; im
materiality of soul not the only
basis of morality, 429; produces
pleasure or pain in conformity to
what takes place in matter, 431 ; is
there, if it is not perceived ? 490.
Souls, always joined to a body, 52,
113 ; of brutes, their conservation
does not require metempsychosis,
53; not perishable, 68, 166; not
absurd to suppose that there are
truths in, which may yet be devel
oped, 80; capable not merely of
knowing innate truths, but of find
ing them, 80 ; all differ, but not spe
cifically, 110 ; never without organs,
220; never without sensations, 220;
a kind of movement attributable to,
231 ; change nothing in the force of
bodies nor in their direction, 233;
as primitive entelechies are infinite,
348.
Soul and body, independent, yet mutu
ally obedient, 68 ; difficulty regard
ing union of, removed by doctrine
of monads, 510, 511 : harmony of,
553.
" Soul and machine," 348, 349.
Sound, heard by teeth and vertex, 122.
Space, views of Locke and Leibnitz
regarding, 12; full of infinitely
divisible matter, 54; with6ut body,
a fiction of philosophers, 114; " full
of cubes?" 124: and solidity, are
they two? 128; a kind of order, 128;
defined, 153; indicates the possible
as well as the actual, 158; has its
reality from God, 159: infinite, no
814
LEIBNITZ'S CRITIQUE OF LOCKE
idea of, 163 ; a vacuum in, consid
ered, 16, 126, 484.
Spain, castles in, 166.
Species, immission of, a theory of self-
perception, 20; intentional, 55, 381;
names of, originally given to individ
uals, 308; receive names of genera,
308 : ascend from, to genera, 309 ; can
be infinitely varied, 314; is the es
sence or idea of, factitious or existent
in nature ? 314 ; are they dependent
entirely on name, 315; its limits,
usually fixed by nature, may be
arbitrary, 328 ; logical, will never be
found,. 331, 332; cannot be founded
on essence or interior constitution,
332 : is their foundation in nature
or in naming ? 335 ; an ambiguity in
connection with terms, 335, 336 ;
what can after change be returned
to its first form, has preserved its
first, 336; in organized bodies, 336;
determined by generation, 336 ; what
constitutes human, 336; all, truth
fully distinguished, have founda
tions in nature, 337 ; in botany,
337; assumptions involved in the
supposition that, are dependent on
model essences, 338 ; may there
not be a common internal specific
mark of? 330 ; if dependent on
propagation, questions concerning,
343, 344 ; which are not unum .per
se, 348 : devised by the ignorant, but
constantly under scientific correc
tion, 349, 350: if work of nature,
why such differing conceptions of?
350; may have real essences inde
pendent of our knowledge, 353 ;
much alike, seldom occur together,
353 : in what, cases passage between
may be insensible, 353; to what
extent we can combine ideas to
produce, 353, 354 ; definition of,
depends on ability and industry
of definer, 354: conceptions of, may
vary. 355 ; may be good and natural,
though not best and most natural,
355 : men determine name but not,
357; mathematical, 357; physical,
357: accidental changes do not af
fect, 358: provisional mark of, 358;
do the house dogs of England and
those of Boulogne belong to different ,
358; infima, 358; dog and elephant,
of different, 358 ; of time-pieces, how
determined, 359 ; all men of one, 359 ;
do not depend on opinion, 360 ; exist
in nature, 360; purely logical, 360;
purely physical, 360 ; founded on
specific civil differences, 360 : nomi
nal, 360; legal, 360; of artificial
things, the hesitation to admit them
into the Predicamental Tables, 361 ;
a rule for determining, practically,
361 ; sensible, 381 ; do we wrongly
think that nature fixed limits to
each by specific essence, and that
this follows some specific name ? 386 ;
a dictionary of simple ideas observed
in each individual of, desiderated,
394; description of, is natural his
tory, 395 ; is being completed by
degrees, 305; why retarded, 395;
will be defined provisionally only
by definitions of genera, 457 ; medi
ate, why kept from our observation,
552 ; connection of, 552.
I Speculative discussion usually affords
two sides, 378.
Speech, the instrument and bond of
society, 285 ; monkeys said to have
organs of, 286 : might consist of
musical tones, 287 : by words more
suited to man's original simplicity,
287 ; organs of, not. in birds who use
words. 287 : man alone can ewiploy
organs of, 287.
Spendthrift, his undue estimate of
"advantage of the present," 200.
Spider's voracity, 91.
Spinoza, " the subtle Jew," cautiously
quoted, 526 ; life of, exemplary, 535.
Spinozists, Leibnitz's relation to, 60;
their views of God, 69; their views
of final causes, 60.
Spirit, existence of, more certain than
that of sensible objects, 229; not " in
loco sed in aliquo ubi," the expres
sion challenged, 230 ; their " ubiety "
detailed, 230; cannot be stripped of
perceptions of past existence, 249;
has presentiments which can be de
veloped, 249; an illustration of a
INDEX A
815
word passing from a sensible origin
to a signification more abstruse,
289.
Spirits, imited to some organic body,
159: related to other bodies, 159;
related to space, 159; can perhaps
assume suitable organs of sensation,
228 ; can operate only where they
are, 229 ; active power perhaps, the
proper attribute of, 233; created,
not totally separate from passive
matter, 234; in the future state,
possess very perfect organs, 393 ;
influence matter, 440 ; form a kind
of State under God, 441.
Spring, a mineral, 240.
" Square is not a circle " : is the idea
innate ? 83, 84.
Square may be known by child, though
its incommensurability with its diag
onal unknown, 100.
" Square equal to circle," how nearly
done, 424.
Stabbing, English opinion of, 326.
" State of Vision " of theologians, 429.
Stegmann, Christopher, a Socinian,
585. [585.
Stegmann, Joshua, an anti-Socinian,
Stoics, their prolepses, 43 ; their views
of the passions, 172 ; their " wrise
man alone free," 179; on future life
and virtue, 208.
Z-rop-yiJ, 91.
Strabo, 345.
Strauchius, 365.
Street-porter surpasses a statesman in
determining the weight of a burden,
273.
Strigil, curry-comb, 394.
Study, 1(>5, 166 ; reasons for aversion
to, 609.
Stupidity, 146.
Suarez, 494.
Sub-exceptions, 480.
Subscription to symbols, 619.
Substance, its existence dependent on
activity, 11; 'a, whose knowledge
and power are infinite should be
honoured,' an innate principle, 23;
how perceived, 24; Locke's view of,
57, 58 ; activity belongs to its es
sence, (JO; immaterial, necessary to
thought, 62; unities of, 66; Locke
denies we have idea of, 105; reflec
tion discovers idea of, 105 ; once in
action always so, 111 ; has a degree
of liquidity, 111 ; activity of, implies
activity of soul, 112 ; Locke's defini
tion, 148; idea of, not obscure, 148;
division of, 148; may God, finite
spirits, and matter be modifications
of a common? 153; do accidents
subsist in ? 154 ; divergency of
opinion between Locke and Leib
nitz upon, 154; that which is active,
218; one created, cannot influence
another, 218; is idea of, due to in
advertence? 225; is assumption of
substratum in, unreasonable? 225;
whence our ignorance of substance ?
227 ; Locke's opinion of, 234 ; .if one
add a quality to the idea of a, does
he change essence of substance, or
perfect his idea of it? 385; an
allegation that ideas of, being fan
cies, prevent advance in knowl
edge, 389; the visible in, gives first
ideas, 392 ; knowledge of internal
constitution of, necessary to ulterior
knowledge both of qualities and of
accidents, 457, 458 ; can it be multi
plied when the individual essence
does not exist ? 589 ; in theology, 612.
Substances, according to Locke, 5 ;
simple, created, always joined to a
body, 52 ; never naturally separated
from matter, 63 ; iiniversally differ
ent, 110 ; internal vortices of, cannot
be stopped, 112; 'these machines
are,' 280; their definition, 317; gen
era and species, only sorts of, 330 ;
ideas of individual names usually
confined to ideas of, 361 ; perfect, to
be distinguished from (aggregata)
assemblages of substances, 361 : di
recting or characteristic qualities in,
392 ; names of, say more than defini
tion, 393, 394; definitions of, arrived
at by study of natural history, 394 ;
do not have their qualities inde
pendent of other substances, 461.
Substratum, 5.
Subvenire, 77.
Succedaneum, 417.
816
LEIBNITZ'S CRITIQUE OF LOCKE
" Summa Theologiae " of Fabri, 586.
Summa rerum, 215, 610.
£i) fj.w voia irdvra, phrase of Hippo
crates, 48.
Sun, birds in the, intelligent, 244.
Suppressions, internal, 77.
Surd thoughts, 191, 193, 196, 198, 210,
265, 270, 287.
Suspension of desire, 202.
Sweden, theological authority in, 611.
Swedish youth, a prodigy iii numbers,
78, 393.'
Sweetness different from bitterness, a
fact of primitive experience, 23.
Swiss Confession, 612.
Syllogism, when terms equivocal, 484;
does it present only a single exam
ple? 557, 562; does it help mind?
557, 558 ; used on authority, 557 ;
if we can reason without it, what
then ? 557, 56-5 ; its forms, 557 : when
to be used, 557, 562, 563; cannot
show connection of mediate ideas,
558 ; its use confined to the schools,
558 ; a possible use for, 558 ; its in-
utility, 558 : serves as spectacles, 559 :
Leibnitz's view of, 559 ; the scholas
tic, not often employed, 559; a most
important and beautiful discovery,
559; a universal mathematics, 559 ;
contains an infallible art, 559; cate
gorical (simple and complex), 560;
hypothetical, 560; disjunctive, 560;
like counting on the fingers, 561,
562 ; it may be trifling, 562 ; useful
in probabilities, 564, 565 ; its use in
invention questioned, 565 ; its scope
as "formal argumentation," 565 ;
Locke's visible mistake about, 567 ;
does not require a universal proposi
tion for its validity, 567 ; a transpo
sition of premises proposed, 568;
begins with universal proposition as
more didactic, 568 ; its doctrine de
pends on " de continents et con-
tento," 569; single, people of a,
608.
Symbolic books, the propriety of
swearing to adhere to, 619.
Sympathy, 391.
Symptom, 113.
Syncategorematic, 161.
Syncretists, 537.
Synthesis, often leads to beautiful
truths, 412.
Syrus, Publilius, 492.
Tabula rasa, is the mind originally
a ? 4, 10, 15, 42, 65, 105 ; of Aristotle,
38 ; a fiction based on imperfect no
tions of philosophers, 109, 110; if
soul a, then when ideas taken away
there is nothing, 110; notion of, rests
really on corporality of soul, 111.
Tacitus, 91.
Taking words for things, 484.
Tartar, 297.
Taste, felt by nose, 122.
Tastes, confused perceptions, 208 ; how
to be treated, 208 ; both of palate
and of soul can be changed, 216.
Teaching, employs general proposi
tions, 475.
Tendency, 174; included in power,
224.
Tenderness, what? 223.
Ten tame n, 38.
Terence, quoted, 459, 492.
Terms, peculiar to each language, 222 ;
dependent on change of custom, 222 ;
general, their place in language, 288 ;
did language originate in, 288 ; how
arrived at, 309, 310; abstract and
concrete, 368 ; abstract, distinct,
368 ; can they be affirmed of each
other? 368, 369; abstract, logical,
368, 369; real, 368, 369; are they
confined to schools, 369; a chaos of,
much time lost over, 442.
Tertullian, his prssscriptiones, 531 ;
'•the impossible must be believed,"
582.
Testimony, may secure moral certi
tude, 247 ; and opinion compared,
530 ; its force diminished as it is re
moved from the original statement,
541 ; the value of contemporary,
541 ; subjects about which it cannot
be obtained, 548.
Tetragonism, 75.
Teutonic language and antiquities
enter into European history, 304.
Thales of Miletus, 463.
"Theatrum Vitte Humanae,"548.
INDEX A
817
Theme, iucomplex, 398 ; complex, 398.
Themes, Avhich are between ideas and
propositions, 398.
Theogony, 361.
Theology, Christian, ridiculed by one
who persisted in explaining its terms
according to their original force,
290 ; based upon revelation, 474 ;
unites with it ' natural ' theology,
474; natural, "the axioms of ex
ternal reason," 474; founded on
"the veracity and attributes of
God,"' 474; natural, theoretical or
metaphysics, practical or ethics,
496 ; reason in, 585 ; logical necessity
accepted in, 588 ; physical necessity
not sufficient to refute a miracle,
588 : a conclusion in, is it to be
judged by its terms or means of
proof? 588; as an indicial term, 627.
Theophilus, why assumed, 69.
Theotisque, 294.
' Therefore,' its use, 564.
Theresa, St., 600.
Theseus, ship of, 240.
Thieving, why praised by Spartans,
263.
Things, not perceived, should not
therefore be denied, 24; of which
we are not conscious are neither in
soul nor body, 51; " themselves," 59;
cannot be and not be at same time,
are there some to whom this axiom
is not known ? 72, 83 ; uniform ab
stractions, 110; substantial, have
each characteristic relations to each
other? 110 ; of the same kind, yet
not perfectly alike, 238; " identical
with a third thing are identical with
one another," denied by some in
theology, 586.
"Think, I, therefore I am," 410, 469.
Thinking, art of, in time of need, 214;
its elements not yet found, 214;
not mnemonics, 214 ; -being, can it
come from non-thinking? 505; not
from the spiritualization of matter
by minute division, 505 ; not by its
configuration, 506 ; not by its organ
ization, 506.
"Thirteen," 283.
Thomasius, Jacob, 606.
Thorn, Council of, 613.
Thought, immediate objects of, 109;
mediate objects of, 109: external
immediate object of, God, 109; in
ternal immediate object of, soul,
109; is what? 135,178; past persists
or memory could not preserve it,
143; an essential act of soul, 166;
what animals have no, 178; trains
of, 182 ; pertains to mind, 218; only
a passive power, 219; should not
think of, apart from things senses
furnish, 220.
Thoughts, and acts, all from depths
of soul, 70; external senses in part
causes of, 70 ; are acts, 84 ; distin
guished from ideas, 119; we are
never without, 119; correspond to
sensation, 119; in general, 119; re
markable, 119; involuntary, 182;
partly from external objects, 182 ;
from remaining impressions, 182.
"Three, is as much as two and one,"
a definition, 410 ; conceals an intui
tive conviction that the ideas are
possible, 410.
Time, " a kind of order," 128 ; is num
ber not measure of motion, 157 ; the
vacuum in, what it shows, 157 ; has
its reality from God, 159; a vacuum
in, concealed, 159; distinguished,
238.
Tobacco-smoking, its spread illustra
tive of spread of tradition, 72 ; illus
trative of habit, 216.
Topics (argumenta) , 398 ; explain, 398 ;
prove, 398; of Aristotle, 498, 541.
Torricelli, tube of, 127.
Touch, qualities of, are modifications
of resistance or solidity, 122.
Traction, in bodies which do not touch,
125, 127.
Trades, how best taught, 628.
Tranquil times of progress looked for
ward to, 437.
Transmigration, Van Helmont's idea
of, 242; held by Rabbins, 242;
distinguishable from transforma
tion, 242; in what sense may be
held, 242; in what sense possible,
243; not conformed to order of
things, 243; of human soul into a
818
LEIBNITZ'S CRITIQUE OF LOCKE
hog, does it make a man? 243; in
volves no apparent absurdity, 245);
of immaterial substance without
same consciousness does not con
vey same personality, 249.
Transparency, artificial, produced by
rapid rotation of a cog-wheel, illus
trative of confused sensitive percep
tions, 459.
Travel, books of, their uses, 548.
Trebeta and Treves, 546.
Trent, Council of, 612.
Trimalchio, 204.
Trithemius, 546.
Tropical use of language, 271.
True and false, belong to propositions,
281 ; how applicable to ideas, 281.
True, the, may be drawn from the
false, 565.
Truth, necessary, alone capable of
proof, 3; what? 4; not founded on
experience, 11 ; seeker of, described,
31 ; he who does not seek it sin
cerely himself dictates to others,
31 ; unknown to brutes, 44 ; imme
diate to understanding and always
present, 45 ; not established by long-
past experience, 45 ; from under
standing alone, 81 ; mind source of,
81 ; cannot be innate unless its ideas
are innate, 84 ; a, may be known
without knowing all about it, 100;
though natural, not known from
cradle, 100; nothing stronger to
influence men than, 198; of sensible
things only in connection of phe
nomena, 421 ; how distinguished
from dreams, 421 ; not a supreme
attraction to man, 437 ; wrhat is
it ? 449 ; is it in agreement or disa
greement of signs ? 449, 450 ; does it
lie in words ? 450, 451 ; Hobbes' view
of, 450 ; as to its division into men
tal or nominal, 451 ; why not have
literal too? 451; its definition as
lying between objects of ideas,
451 : common to us with God and
angels, 451 ; its provisional indica
tion, 451; moral, what? 452; meta
physical, what? 452; lies in the
correspondence of propositions in
ihe mind with the things in ques
tion, 452 ; certainty of, 454 ; is there
theological, opposed to philosophi
cal, each being true ? 581 ; how
judged of, 611.
Truths, speculative and practical, the
same, 23 ; do all depend on experi
ence ? 43 ; necessary, of mathematics
do not depend on examples, 43 ; yet
such truths may be evolved by the
senses, 44; necessary, how discov
ered, 44; necessary, 68; of fact,
69 ; origin of, 71 ; necessary, their
origin, 71: particular, sooner per
ceived, 74 ; their proof dependent on
more general, 74 ; of arithmetic and
geometry innate, 76 ; imprinted on
the soul, yet not always perceived,
77 ; of fact, 78 ; necessary, 78 ; are
innate which can be drawn from
primitive innate truths, 79; are
innate when their proof lies in what
is within and not in what is given by
experience, 80; either necessary, or
stores of experience, 81 ; universal,
we cannot be assured of by induc
tion, 81 ; have their necessity in
reason, 81 ; necessary, their source
in intellectual ideas, 82 : are they
subsequent to ideas ? 82 : express
knowledge of, how subsequent to
express knowledge of ideas, 82 ; that
are within us are habitudes or dis
positions, not thoughts, 84 ; of rea
son not so evident as immediate or
identical truths, 86 : opinions taken
as, which are only effects of custom
and credulity, 98, 99.
Truths, individual, only given by
senses, 11 ; knowledge of, not in
nate, 21 ; actual consideration of,
not innate, 21 ; contingent, how
they come to us, 22; of fact, how
they come to us, 22; necessary
derivative, what they depend on,
22 ; primitive, their source, 22 ;
dependent on divine mind, 277;
negative, 289; primitive, known by
intuition, 404; divided into those
of reason and those of fact, 404 ; of
reason, identical, 404; affirmative
and negative, 404, 405; identical,
negative, which belong to principle
INDEX A
819
of contradiction, 405 ; primitive, of j
fact, are immediate internal experi
ences of an immediateness of feel
ing, 410 ; not to be confounded with
their expressions, 451 ; general, their
establishment more important than
resolution of particular cases, 467 ;
their natural and historical order,
470 ; why many pass as self-evident,
yet are capable of farther reduction,
473 ; of experience and truths of
pure reason compared, 493; eternal,
at bottom conditional, 515; neces
sary, are determining reasons and
regulating principles of existence,
516; anterior to existence of con
tingent beings, 516 ; grounded in
necessary substance, 517 ; in mind
originally not as propositions but
as sources of judgment, 517.
Tulpius on man-like ape, 244.
Tunica, cloak, 394.
"Two and two are four/' its demon
stration, 472.
" Two homogeneous magnitudes are
equal when one is neither greater
nor smaller than the other " : an ax
iom of Euclid and Archimedes, 473.
Ubiety, circumscriptive, 230; defini
tive, 230 ; repletive, 230.
Unconscious pain, 195.
Understand, not to, a thing, no ground
for denial of its existence, 60; to,
what? 177.
Understanding, " to be in," according
to Locke, and according to Leibnitz,
81 ; a resemblance to, 147 ; adds re
lations, 148 ; the origin of all things,
N8 ; what ? 177 ; animals have none,
178; corresponds to intellectus, 178;
its action intellection, 178; guardedly
called a faculty of soul, 178; with
out freedom of no use, 216.
Uneasiness, 49, 171, 172; as a stimu
lus, 168; expressed by "inquie
tude," rather than "chagrin," 169;
its influence on will, 188; may be
an insensible perception, 188; not
always a displeasure, 188; arises
from nature's efforts to put herself
more at ease, 194 ; determines in
cases apparently indifferent, 194;
the field of a series of little suc
cesses which afford pleasure, 194.;
not incompatible with happiness,
194; consists in feeling without
knowing it, 194 ; more pressing not
always prevalent with will, 200.
Unhappiness, the result of false judg
ments, 209.
Unities of substance, 66.
Unity of languages can only be at
tributed to migration of peoples,
297.
Unity, perfect, not secured by homo
geneity, reserved to animated bodies,
362.
Universality, never proved by experi
ence, 22 ; in what it consists, 567.
Universals, are they real? 313; com
prise (in form) particulars, 567,
Unpremeditated actions, result of
minute perceptions, 116.
Unruhe, term applied to pendulum,
171.
Unum ex primis cognitis inter ter-
minos complexes, 469.
Urim and Thummim, early teachings
a sort of, 611.
"Utilitate Credendi, De," of Augus
tine, 616.
" Utriusque," 227.
Vacuum, 65 ; Locke and Leibnitz upon,
16; is it necessary to motion? 53;
excluded, 68 ; perfect cannot be
proved by experiment, 127 ; would
opposite sides touch in ? 155 ; in
time and space, 159; abhorrence of,
can be soundly understood, 381 ;
denied by Descartes and Leibnitz,
483 ; in forms or species, 552.
Valla, Laurentius on the Jurists, 415.
Van Helmont on transmigration, 242.
Vandal king, 99.
Vayer, La Mothe le, 593.
Vedelius, his " Rationale Theologi-
cum," 587, 588, 595.
Vega, Garcilasso de la, 89.
Vegetative souls, not to be lightly dis
carded, 380, 381. .
Velleity, 168, 1C.9.
Velleite, what ? 188.
820
LKIUMTZ'S Clil Tigi:i-: OF LOCKE
Venus Urania and the bastard Venus,
390.
Vergil, 200, 415, 598; on the praise of
virtue, 263; quoted by the Priscil-
lianists, 345 ; quoted by Coperni-
cans, 614.
Versurct, 326.
Vice, by what standard adjudged a,
261, 263; its relation to sin, 262.
Vieta, extended algebra, 468, 573.
Vincent de Lerins, his " Commoni to
ri um," 617.
'• Vindication of Doctrine of Trinity,"
by Stillingfleet, 56: Locke's opin
ions examined in, 56: ensuing con
troversy, 57.
Viottus, 520.
Vires centripetse, 132.
Virgil of Salzburgh, 443.
" Virtually," defined, 78.
Virtue, its meanings, 95 : the philo
sophic notions of, 96; Aristotle's
definition of, 96 ; a pleasure of mind,
167 : its success if fashionable for a
day, 198 ; is useful, 261 : not depen
dent on opinion, 262 ; and vice, are
they founded on tacit consent? 262;
what is generally praised is usually
worthy of praise in some respects,
263; the term, and that of praise
often applied to same quality, 263,
264 : praise attributed to, in Vergil
and Cicero, 263, 264 ; is it that which
is praised, or that which is worthy
of praise? 264 ; called ' honesty ' by
ancients, 264.
Visions, what? 166: divine, 166; state
of, 429.
Vivacity of mind, what? 143.
Vives, Ludovicus, 591.
Vladislas, king of Poland, 612.
Volition, what? 177: a result of con
flict of perceptions and inclinations,
199 ; has at bottom perceptions only
perceptible in mass, 199; most press
ing uneasiness not always prevalent
to secure, 200 : obeys sometimes a
'compound direction,' 200: finally
determined by result of tendencies,
200: mind can employ the dichoto
mies to vary influence, 200.
Voluntary, defined, 177 ; and free, 187 ;
and involuntary not distinguishable,
553.
Vulcan's buckler, 479.
Water, its apparent compression due
to air, 126: changed into wine on
Christmas Eve, 470.
Waterfall, why unconscious of its
noise? 47.
Water-mill, 117.
Weigel, his moral diagrams, 435.
"Whatever is, is" not universally
known, 72.
"White is not red," 83.
Whiteness, what? 163.
"Whole, the, is equal to its parts,"
not expressly used by Euclid, 471 :
its limitations, 471.
Wilkins, Bishop, his artificial lan
guage, 292.
Will, not exclusively influenced by
assurance of greater good, 26; influ
enced by present unrest accompa
nied by desire, 26: what? 177; and
power united, action follows, 177 :
" is free," phrase discussed, 185, 186 :
and understanding, relation of, 185;
may suspend its exercise, 186; acts
in advance of, may influence, 187 ;
action of, determined by what
pleases, 188; what determines the,
188; and desire distinct, 188; what
determines, not greater good, 188;
some actual uneasiness, 188; great
est good fails to influence, because
not strongly sensible to us, 192 : re
moval of present pain determines
it, 194; why so little swayed by
thoughts of future life, 196; and
desire, why confounded, 198; its
intelligent determination desirable.
204 ; its indifference an imperfection,
204 ; absolute indifference never pos
sible, 204; in cases of seeming indif
ference it is yet determined by a
concurrence of internal dispositions
and external insensible impressions,
204; determination of, useful, 205:
secures effective choice, 205; deter
mination of, if it exists in anything
but final choice, not free, 205 ; com
plete in superior beings, yet they not
INDEX A
821
less free, 205 : in God secured by
what is best, 206; in God not fixed
by necessity, 206: secured by incli
nation, 206; to the best, is freedom,
206; should be determined by hap
piness in general, 206; should be
determined by particular goods only
when found agreeing with our true
happiness, 206 : and taste under one
control, 207 : acts by present percep
tions, 211 ; acts by present image of
the future, 211 ; acts by discomfort
of opposition to a resolution or
habit, 212.
Wisdom, the science of happiness,
377.
Witt, Pensionary De, 426; on Annu
ities, 540.
Wittemberg, 611.
Witty sayings not to be too rigorously
treated, 144.
Worcester, Bishop of, Locke's reply
to second letter of, quoted, 54, 55; |
on immortality of soul, 58.
Words, the twofold abuse of, 270; re
present and explain ideas, 285; trans- j
ferred from origin in simple ideas !
to more abstruse significations, 289;
their tropical signification depends
on analogy between the sensible and
non-sensible, 290 : are the meanings
of, arbitrary? 292: the use of, im
plies that speaker has ideas, 305 ;
may sometimes be those of another
than speaker, 305 : hollow use of,
305 : speaker of, means something
general, 305; men often think more
of, than things, 305; connect them
selves with ideas and things, 305,
30H : often secure attention to exclu
sion of things, 305 ; are supposed to
have a secret relation to another's
ideas, and to things, 305; form
of, what? 305; are often parrot's
sounds, 305 ; as applied to simple
ideas and modes, 30(5; as applied to
substances, 306; spoken of some
times in a material way, 306 ; largest
number of, are general terms, 307 ;
originally general terms, 308; how
they become general. 309 : genus and
difference employed in defining, 312 ;
dichotomous definitions of, best, 312 :
their use, 356, 357; their analysis
shows best the workings of the
understanding, 368; their imperfec
tions, 369; double use of, 369, 370;
civil use of, 370; philosophic use of,
370 ; are notas for us and others, 370 ;
cases in which it is difficult to learn
and to retain ideas of, 370; how
their defects may be remedied, 373;
have a double relation to things
signified, 374; those which indicate
simple ideas not wholly unequivo
cal, 375 ; those which indicate simple
modes least doubtful, 375; act as a
medium between understanding and
thing, 375; removal of imperfections
of, would lessen disputes, 375: re
form in use of, suggested, 375;
uncertainty in regard of, should pro
duce modesty in controversy, 376;
have changed much in Latin and
other languages, 376 ; have changed
little in Greek authors, 376; Italian,
have not changed so much as French,
376 ; imperfections of, arising from
intention and negligence, 376; are
abused, when we attach no clear
ideas to, 376 ; there are, which never
had a definite idea, 377; there are,
which have lost their first idea, 377 ;
insignificant, not many, 377 ; abused,
because we learn them before their
ideas, 377 ; bad use of, leads to mis
construction, 378; abuse of, from in
constancy of use, 378; inconstancy
of use in, dependent on inadvertence,
378; abuse of, through affected ob
scurity, 378; abused, when we take
them for things, 379; pardonable
and praiseworthy obscurities of, 379 ;
not so much taken for things as be
lieved to be what they are not, 380;
are abused, when used for things
they cannot signify, 384; are they
abused when applied to complex-
ideas as if these had a real essence
on which the properties depend?
384; abused when we attach certain
ideas to them, and then suppose
that everybody accepts our mean
ings, 387; their uses, 388; corre-
822
LEIBNITZ'S CRITIQUE OF LOCKE
spending defects, 388; abuse of, in
figurative terms and allusions, 389 ;
remedies for the philosophic abuse
of, 390 ; always use, with ideas, 391 ;
ideas of, applied to modes should be
more determined and those of sub
stance carefully conformed to what
exists, 391 ; usage should be re
garded in, 391 ; when new are used,
or old ones in a new sense, the
sense in which taken should be
declared, 391 ; for simple ideas are
explained by synonyms or by show
ing the thing, 391 : conveying mixed
modes are explained by definition,
391 : diagrams remedy uncertainty
of, 433 ; put in place of things, 451.
World, ideal, 326; existing, 326.
Wormwoods, Bauhins on, 308.
Worsley, 259.
Writing, characters in, what? 512.
Ximenes, Cardinal, his cure by Moor
ish woman, 623.
Yellowness not sweetness, 83.
, Aristotle's, 495.
Zopyra, 43.
Zwinger, " Theatrum Vitse Humanae,"
548.
Zwingli, on salvation of heathen,
595.
Zwinglians, 589.
INDEX B
TO THE APPENDIX
Act, to, a mark of substance, 671.
Acta Eruditorunt Lipsiensium, 699,
705.
Action, moving (actio motrix, I' action
motrice), 661, 703; moving, general
rule of, 661 ; and reaction, law of,
689; composed of body, time, and
force, 702.
" Agreement, natural," as a theory
explanatory of relation of body and
soul, 709.
Agrippa, his angelic obstetrician, 646.
Anaxagoras, his sophism concerning
black snow, 639.
Angle, the right, the determinate of
all angles, 694.
Antitypy, dvriTvn-ia, 637,645, 647, 648.
Ape and the infant Christian of Den
mark, 697.
"Airopa, 657.
Apparent phenomena, what? 719.
Archaeus (hylarchic principle) of
Henry More, 679.
Ariosto, his hippogryphs, 718.
Aristotle, his &v<riKr] 'A.Kp6a<Tis, " Phys.
Auditus," 634, 641 ; his teachings
compatible with Reformed Philoso
phy, 634, 635, 636, 645; "the irrec
oncilable," 634; his view of "vac
uum," 634, 699; his " Ethics," 635 ;
his "Logic," 635; his "Metaphys
ics," 635, 642; his " Physics," 635 ;
his meaning perverted by the scho
lastics especially in physics, 635, 636;
incorrectly represented to say that
geometry was not a science, 642;
his "Analytics," 642; places origin
of motion in mind, 643, 651 ; how he
regards form as a cause of motion,
643 ; does not employ the " substan
tial forms" of the Scholastics, 643;
ascends to the First Mover, 643 ; his
definition of time, 645: his "pri
mary matter," 651 ; his " vortices,"
651; adds intelligence only to prin
cipal rings of his vortices, 651, 680;
his geocentricism, 651 ; his errors
extenuated, 651 ; his eutelechies,
e^reX^xftai, 671, 699, 701, 712.
Atheism, its prevalence in Leibnitz's
time, 648; a philosophy which af
forded a unique plank by which
men could save themselves in the
shipwreck of impending, 648.
Atoms, there are no, 652; defined,
653; of any figure, 653 ; it is impos
sible for all bodies to consist of,
demonstrated, 653; scholium to
demonstration against, 654; appen
dix to demonstration against, 656;
do not exist, since their existence
would make change of motion take
place by leaps, 669, 686 ; do not ex
ist, since curvilinear motion is com
posed of rectilinear motions, 690;
theory of, opposed to subtlety of na
ture, 712.
Averroists, on " interminate " quan
tity of matter, 637.
Bagheminus, as a writer, 632.
Basnage de Beauval, his " Histoire des
Ouvrages des Savants," 706.
Bayle, Leibnitz's explanation of the
difficulties presented by, to the the
ory of pre-established harmony, 706.
Being, A Unique, 692; how He rules
the world, 692 ; is ultimate reason of
81i3
824
LEIBNITZ'S CRITIQUE OF LOCKE
things, 692 ; His existence not to be
escaped by assuming eternity of the
world, 692, 693-, He exists of meta
physical necessity, 693; is free yet
determined, 695; in Him essences
and eternal truths exist, 695 ; the
connection of all things with each
other proves Him their one source,
696; that the most perfect, exists,
714 ; what ? 717.
Beings, all natural, form only one
chain, 713.
Bodin, his dangerously atheistical
"Arcana Sublimium," 648.
Body, defined, 647 ; enquiry after con
stitutive quality of, 647, 700 : infinite
creatures are in any given, 652, 702;
coheres with its fellows, 652 ; never
wholly quiescent, 652, 657, 699, 703 ;
errors arising from false notions of,
684 ; Leibnitz's view of, 684 ; differ
ence between the views of Leibnitz
and Descartes concerning, 699 ; what
the nature whose diffusion consti
tutes? 700; a "machine," 701,702;
cannot be destroyed nor absolutely
produced, 702 ; has a degree of prim
itive activity, 702; conspectus of
systems presented as explanations
of union of, with soul, 709.
Bodies, all that is in, explicable by
magnitude, figure, and motion, 634,
648 ; are something during, nothing
between, instants of motion, 648;
particular, arise from conflicting
motions, 652 ; are all elastic, 668, 687,
703 ; their action against each other
the same, if they approach with
same velocity, 685 ; no elements of,
687 ; distance between, never the
same, 690; their phenomena can be
explained mechanically, 699; can
not demonstrate existence of, 719.
Boeder, 650.
Bnrgoldensis, probable author of
" Itinerarium Politicum," 650; com
mentator on " Instrumentum Pads,"
650.
Campanella, his "De Sensu Rerum et |
Magia," 646.
Cartesians, have added little to dis- !
coveries of Descartes, 632 ; Leibnitz
refuses to be classed among, 634; re
lations to the ancient philosophers,
645; "subtile matter" of, 651; on
communication of motion by im
pact, 685, 688, 704; admit no vac
uum, 699 ; essence of body, according
to, 699 ; acknowledge inertia, 701 ;
reject action in bodies and find it in
God, 703; modifications of views on
force, 704 ; suppose a body in mo
tion proceeds per saltum, 704; the
disciples among, not so careful in
statements as their master, 705 ; as
sume redundantly the "Deus ex
Machina," 709; posit "primary
elements" instead of veritable
unities, 712; their reasoning con
cerning the existence of the most
perfect being, 715.
CAUSE, THE, through which minds
have intercourse, 720.
Causes, final, agents in research, 680;
both final and efficient, pertain to,
and help in physical discussion, 704.
Centaur, the species of, exists in mind,
718.
Change, spontaneous, admitted by
philosophers in simple being, 711.
Changes, enumerated, 638; reduced to
forces, 706.
Cicero politely laughs at Epicurus,
643; his " De NaturaDeorum," 643.
Classes of beings, linked together in
one chain, 713; their limits cannot
be precisely given, 713.
Coins, how two of different metals
may be distinguished, 653.
Collegium Philadelphicum, 650.
Colors, arise from motion, 639.
Column, how extracted from the rough
block, 638.
Conatus, 671, 673, 675, 678, 695, 701,
702, 706.
Concurrent bodies, same relative ve
locity preserved between, 658;
"total progress" preserved be
tween, 658; absolute force con
served in, 659, 660; why they can
stop each other, though unequal in
"living force," 660; augmentation
of "living force " in, would lead to
INDEX B
826
perpetual mechanical motion, 661 :
diminution of "living force" in,
would lead to destruction of force,
661 ; conservation of " moving ac
tion " in, general rule as to, 661
conservation of " moving action '
in, general demonstration of, 663
conservation of "moving action'
in, proved by an example in num
bers, 663; conservation of " moving
action "in, proved by rules of per
cussion, 666; lineal equation which
expresses conservation of cause of
impact in, 6(57; plane equation
which expresses conservation of
total progress in, 667 ; solid equation
which expresses conservation of
total absolute force in, or of " mov
ing action" in, 667; the interde
pendence of the three equations con
cerning, 668 ; are to be regarded as
"hard-elastic," 668; influence of
degree of elasticity in, 670 ; both act
equally in concourse, 688 ; compres
sion from impact equal in each of
them, 689.
Conditions amid space, 645.
Congruity of phenomena, 718.
Connection between all parts of uni
verse, 713.
Corn-ing, Hermann, 636 : on forms, 638.
Continua, how defined by Aristotle,
637 ; of two kinds, 700 ; successive,
700 ; simultaneous, 700.
Continuity, law of, 668 : excludes
change per saltum, 687 ; applied to
zoology and botany, 713.
Continuum, 687.
Corporeal things, more involved in
their explanation than geometry
and logic, 679.
Corpuscle, each, awaits an occasion
of exercising its power, 705.
Corpuscular philosophy, its abuse, 672.
Corruption and its correlative genera
tion result from motion, 639.
Creation, continuous, in motion, 648,
650, 679; a Divine Mathematics or
Metaphysical Mechanics in, 694.
Dance, tight-rope, why pleasing? 697 ;
sword-, why pleasing? 697.
Death, if we awaken in, Avhat then?
719.
Democritus, his atoms freed from con
tempt, 671 ; regarded body as inert
mass, 677; holds a vacuum, 699:
regarded rarefactions as only ap
parent, 699; thought there was
something passive in body, 699;
taught that the phenomena of bod
ies can be explained mechanically,
699, 712.
Descartes, Clauberg clearer than, 632 :
disciples of, 633; argument of his
method the only distinctive doctrine
of, held by Leibnitz, 634; his "Me-
ditationes," 634; opposes vacuum,
634, 699 ; contends for plenum, 634 ;
" subtile matter " of, 651 ; his "uni
versal rings," 651; distinguished
velocity from direction, 675; re
garded motion quoad phenomena as
mere relation, 685; his inaccurate
statement about concourse of a
larger and smaller body, 685 ; de
nies that all reflection arises from
elasticity, 687 ; a testing application
of his co-ordinates to conditions of
motion in concurrent bodies, 688:
saw only extension in body, 699;
believed that phenomena of body
could be explained mechanically,
699; acknowledged natural inertia,
701 ; believed force to be a compo
site system of mass and velocity,
704; found no reason for assuming
forms and forces in bodies, 705 ;
his assumption that the notion
of a perfect being exists criticised.
715.
Deuncali, substantial forms virtually,
646.
Deusing, 632.
Development in perfect order, the law
of all things, 712.
Dig-by, Kenelm, 632; his " Peripatetic
Institutions," 641.
Discontinuity, how induced in primary
matter, 637.
Dreams, how related to body, 708;
well-ordered, are equivalent to truth,
719.
Duration, defined, 700.
826
LEIBNITZ'S CRITIQUE OF LOCKE
Effect, violent, what? 659, 662.
Effort, an illustration of, 674 ; is two
fold, 674.
Elasticity, whence? 668; everywhere
present, 669, 687; often insufficient,
669; all reflection comes from, 677,
687 ; necessary to laws of motion, j
703; necessary to "law of continu- '
ity," 704; necessary to "law of!
equivalence," 705 ; assists in uniting j
" necessity of matter with beauty of
form,'' 705; shows the presence of
internal motion and infinite primi
tive force, 705.
Ellipse passing into parabola used as
an illustration, 687; may represent
a circle optice, 717.
Energy, primitive, 703.
Entelechies, e^reXex^at, 671, 672, 679,
680, 699, 701, 703, 705, 712.
Entities, the only given, 645.
Epicurus, 643, 644; bestows per se
downward motion on his atoms, 643 ;
laughed at by Cicero, 643; denies
motion from without, 644 ; admitted
progress into infinite, 644.
Equilibrium, what? 659; relation of
heights and weights in, 659.
Essence, or possibility itself, 693, 695 ;
of matter, 637; of body, 647, 671,
678, 684, 699, 700.
Eternity, of world, does not set aside
an extramundane reason for its
existence, 693 ; of existence does not
explain existence, 719, 720.
Existence, its sufficient reason not in
a succession of states, 692; not in
things, 692 ; essence per se tends to,
693 ; quantity of, greatest possible
under conditions, 694 ; in the num
ber of the perfections, 715 ; how
proved? 717.
Express, to, what ? 716.
Extension, what? 647, 671, 699, 700;
howAve conceive, 711.
Eeelings of soul, a consequence of that
which is in it, 707.
Figure, what? 637, 645, 703; arises
from motion, 642.
Flowing, free curvilineity, (J40.
Force, and quantity of motion, not
the same, 659; absolute, to be meas
ured by violent effect, 659; dead,
the equivalent of equilibrium, 659;
when living, developed, 660; how
dead, estimated? 660; how living,
estimated, 660; is twofold, 674;
dead, or elementary, 674; living, is
twofold, 675; total living, 675; par
tial living, 675; partial respective,
675 ; partial directive, 675 ; total ab
solute, how composed, 675; — prim
itive active, 701; is the ei/reX^x^a
'{] irpuTT) of Aristotle, 701 ; is form of
substance, 701 ; how affected by im
pact, 703; —derivative, what? 702.
703: its amount maintained, 702;
differs from action, 702; — active,
placed in bodies, 702 ; originally in
God, 702 ; internal, turns itself with
out, 703.
Forces, how they exist, 704.
Form, what? 637: substantial, con
sists in the indivisible, 640; what,
according to Scholastics, 643.
Forms, from active power of Efficient
One, 632; how they originate, 638;
substantial, endowed with intelli
gence, 646; appetite assigned to,
646; axioms connected with, 646;
— how the doctrine of, must not be
employed, 672.
Full, all things are, 652.
Galileo, his expression "the infinite
force of percussion," 674 ; his inves
tigations concerning living force,
675.
Gassendi, 632 ; not strictly a Cartesian,
633; contends for a vacuum, 634,
699; places body in inert matter,
677 ; his remarkable experiments,
691 .
Generation, how explained by motion,
638.
Geometry, demonstrates from causes,
642 : Aristotle's view of, 642 : is a
science, 642; denned, 700; its rela
tion to arithmetic, 700.
Glanvill, Joseph, his History of the
growth of science since Aristotle,
631.
God, the primary matter of things,
INDEX B
827
632; forms produced from his ac
tive power, 632; produces creatures
from his active power, 632 ; must
not be introduced in explanation to
the exclusion of acting in things,
679 ; free, yet does all things deter-
minately, 695; in him not only ex
istences but possibilities have reality,
695 ; progress to be recognized in his
works, 698 ; how beings exist in the
ideas of, 712 ; world in a measure
represents, 717 : not a deceiver, 719 ;
is Cause of intercourse between
minds, 720; is a Cause, but has no
cause, 720.
Goezius, publishes the " Collegium
Philadelphicum," 650.
Greatest expressed in smallest, 712.
Gyri, 651.
Heat, a form of motion, 639.
Hermetics, 712.
History, how confirmed, 720.
Hobbes, 632; not strictly a Cartesian,
633 ; asserts possibility of both ple
num and vacuum, 634; his vortices,
651.
Hooke, his " Micrographia," 639; his
" Sylvula " of rust, 639.
Huygens, his "method of a boat,"
(566; adorns the age with splendid
discoveries, 676.
Hypotheses, rule for choosing among,
637.
Hypothesis, the, of modern philosophy,
637; a defect in, 646.
Idea, something in mind, 716 ; not im
pression on brain, 716 ; not every
thing in mind is an, 716; is a power
in mind, 716; may exist without
thinking, 716 : a power near at hand
of thinking about a thing, 716 ; must
not only tend to the thing, but ex
press it, 716; need not resemble its
thing, but it presents truths which
would be confirmed in the thing, 717.
Ideas for which the age was not pre
pared, 714.
Impetus, what? 673.
Impulse, made from infinite degrees,
674.
Incompatibility, only demonstrated by
resolution of terms compared, 714.
Increment, the momentary, in a force
striving for change is real, 671.
Indifference of will, arises from igno
rance, 695.
Infinite, should be recognized in every
thing, 712.
" Influence, the system of," the Scho
lastic method of explaining connec
tion of body and soul, 709.
Intelligences, of Aristotle, 651, 711:
discarded, 680; — used by God not
as machines but subjects, 698, 702.
Intercourse, and by consequence ex
istence, of minds, its cause in God,
720.
" Journal des Savants," 707.
" Journaux," 699.
Joy, the law of, 697.
Justice, the law of, 697.
Kabbalist, 712.
Kepler, 701.
Laws, mechanical, from higher reas
ons, 680; of God imply means of
accomplishment, 709.
" Leap," no change by, 669, 686.
Leibnitz, how far a Cartesian, 634;
his juvenile production, "Hypothe
sis Physica," 677 ; his maturer judg
ment of " Hypothesis," 695.
Light from motion, 639.
Living force, see Force.
Malebranche, his " Search after Truth,"
657 ; his rules of motion, 688.
Marci, Marcus, his"De Ideis Opera-
tricibus," 646.
Mariotte, on rules of motion, 677:
points out that a body bends before
it is propelled, 687.
Matter, defined, 645; subtile, of Des
cartes, 651 ; tends to rest or anni
hilation, 652 ; infinitely divided, 652 ;
more than extension, 700.
Matter, primary, what ? 637, 672 ; dis
continuity in, how effected, 637;
how all things produced from, 637 ;
of Aristotle, 651 ; and space the
828
LEIBNITZ'S CRITIQUE OF LOCKE
same, 652 ; if at rest is nothing, 652 ;
obscurely hinted at by Scholastics,
(552; if moving in parallel lines is
nothing, 652.
Mechanics, ancient, dealt with dead
force, 675.
Mechanism, a physical, illustrative of
metaphysical problems, 695.
Mercury, the basis of all metals, 640.
Metals, whence they arise, 640.
Metaphysical laws prevail over geo
metrical, 695.
Mind, source of motion, 643: liberty
and spontaneity alone in, (543: de-
tined, 645.
Mobile, 673.
Molyneiix, his " Dioptrics," 680.
Moral perfection is physical, 696.
More, Henry, his Archaeus, 679.
Motion, originates in mind, 643; de-
tined, 645, 673; not given in bodies,
648 ; a continual creation , 648 ; source
of all particulars, 651 ; is circular,
652 ; and body, 652 ; in what case
not external, 652: same quantity of,
not preserved in concurrent bodies,
657; quantity of, what? 657, 673;
never exists, 671 ; term applied to
instantaneous element of motion,
(573; systematic rules of, 678, 679;
why real, 685; a relation, 685; Des
cartes' mistakes in relation to, 685 ;
proper, separated from common, 689 ;
as a tendency rectilinear, 689; why
curvilinear, 690; its true nature,
690, (591 ; when common in many
bodies, does not change their action
among themselves, 691.
Motions, their compositions and resolu
tions, 691, 692.
Motive force, in bodies intrinsically,
699.
Natural history, discoveries expected
in, by employment of Law of Con
tinuity, 713.
Nature, Two Laws of, which Leibnitz
first made known, 668: Aristotle's
definition of, approved, 699.
Naudaeus, 648.
Necessity metaphysical, 693 ; physical,
693; hypothetical, 693.
" Nouvelles de la Republique des Let-
tres," 687.
Number defined, 645.
Order, a general principle of, 687 ; its
foundation, 687; its enunciation,
687 ; its illustration, 687.
Origin of things, on the radical, 692.
Paradise, why the world is not yet a,
698.
Parts not neglected for sake of total
ity, 697.
Passion of bodies, spontaneous yet
occasioned, 688; proper, arises from
percussion, 688.
Perfection is quantity of essence, 693;
is degree of essence, 695 ; that through
which greatest number of things are
compossible, 695 ; a source of ex
istence, 695.
Peripatetics, their forms referred to
intelligible notions, 671.
Phantasmata. how certified that things
are not, 647.
Philosophic temperament, the, which
suits piety and science, 680.
Philosophies, none of them worthy of
contempt, 671.
Philosophy, the Reformed, its com
mon rule, 634 ; its reconciliation with
Aristotle, 63(5; its relations with
Aristotle, 645.
Physics, why misunderstood by Schol
astics, 63(5.
Plato, his Ideas, 671 ; his entelechies,
699.
Platonists, 712.
Plenum, 634.
Position, defined, 645.
Possibility, is essence, 693, 695.
Power, active, is force or form, 701 ;
a tendency to action, 701 ; not a
faculty, 701 : is primitive or sub
stantial, 701 ; is derivative or acci
dental, 701.
Power, passive, is matter, 701 ; is im
penetrability or antitypy, 701 ; is
resistance or inertia, 701 ; is every
where the same, 701.
Power in body, twofold, 701.
Progress, quantity of, what, 658; of
INDEX B
829
universe never comes to an end,
698.
Projectiles, G91, 702.
Putrefaction, 638.
Quadrat ices, 711.
Qualities, changed through motion,
639; depend on organs, 640; with
exception of forms reduce to forces,
706.
Ranis, on Aristotle, 641.
Reality, both of essences and exist
ences, their ultimate reason, 695.
Red Cross, Society of, 650.
Reiser, Anton, 649.
Repetition, discrete or continuous, 700.
Rest, evanescent motion, 687; "ex
cludes leap from change," 687; ad
vantage of regarding it as a case of
motion, 687, 688; not cause of sta
bility, 690; true, does not exist,
690.
Rings in primary matter, 651.
Rust, 639.
Salts, their nature, 640 ; the causes of
fixity, 640.
Sarmatian salt-pits, 696.
Scaliger, harmonized Aristotle and
moderns, 641 : his Stfi/a/xis TrXcurTi/ci^,
646.
Scholastics, their queries concerning
primary matter, 637 ; their relation
to mathematics, 642.
Schurzfleisch, 650.
Sciences, " a certain harmonizing of
the," 642.
Snow, what ? 639.
Solicitation, an infinitely small mo
tion, 659, 674.
Solidity from motion, 651.
Souls and entelechies, we give no place
to, 680; why so much conferred on?
698; concentrate universe in them
selves, 698; always connected with
organic bodies, 701.
Space, defined, 645 ; why real, 684, 685 ;
no vacant, 690 ; in what sense said
to be extended, 700.
Spener, 649.
Sphericity, tendency of bodies in flu
idity to assume, 694.
Spizel, his "Confessio naturae contra
Atheistas," 649.
Stability, true notion of, 689; abso
lute, does not exist, 689; defined,
690 ; not derived from rest, 690 ; not
explained by pressure, 690.
Stoics, tranquillity of, 671.
Substance, changed by motion, 639;
what happens in, happens in an or
derly manner, 686; apart from soul,
an aggregate, 701.
Sufferings of good men result in greater
good, 698 ; short roads to perfection,
Theologians and philosophers discuss
the same questions, 644.
Thing, a, how distinguished from other
things, 652.
Things, corporeal, possess tendency
or effort, 671 ; something has been
placed in them by God, 679 ; are part
of the Kingdom of Power or of the
Kingdom of Wisdom, 680 ; existing,
in what sense necessary, 693; their
original formation, 693, 694 ; reasons
of, not found in their series, but in
metaphysical truth, 695 ; depend not
on material necessities, but formal
reasons, 695.
Thomas Anglus, on immortality of
soul, 641.
Thomasius, Jacob, Leibnitz's letter to,
631.
Time defined, 645, 711 ; Aristotle's defi
nition of, 645 ; never exists, 671 : real,
684.
Trew, Abdias, 641.
Truths, contingent, originate in meta
physical, 693; — eternal, exist in a
metaphysical subject, God, 695 ; reg
ulate things, 695; are reasons of
existence rather than non-existence,
695 ; are reasons of the so-existing
rather than the otherwise-existing
world, 695 ; prevail over geometrical
laws, 695.
" Uniformly," how applied to action of
830
LEIBNITZ'S CRITIQUE OF LOCKE
" Unities, veritable," to be posited at j
foundation of things rather than j
" primary elements," 712.
"Unthinking, the," nothing, 652; no
variety in, 652.
Vacuum, 634, 635, 638, 699, 708, 712.
Vaninus, 648.
Velocity, relative, between concurrent
bodies, preserved, 658 : how esti
mated, 662; denned, 673; with di
rection called conatust 673; distin
guishable from direction, 675.
" Vividness," of phenomena, 718.
Vossius, his criticism on Descartes,
634.
Wallis, 677, 692.
Water, elastic, 703.
Weights in motion exhibit the greatest
possible descent of heavy bodies, 694.
Weigel,641.
White, the color, 639.
Whole never exists, 671.
Wisdom determines to the most per
fect, 695.
World, the four things necessary to
explain its phenomena, 646 ; in
it is realized the greatest produc
tion of possibilities, 694 ; physically,
not metaphysically, necessary, 694 ;
— this, not the best, apparently
shown by experience, 696 ; a priori
argument against, 696 ; a supposi
tion founded on partial knowledge,
696 ; the most perfect possible,
6%; the most perfect physically,
696 ; the most perfect morally, 696 ;
an admirable mechanism and the
best Republic of Souls, 696 ; its evils
but as purposed discords in a musi
cal composition, 697 ; represents God,
717.
Wren, 677.
Zeno, Leibnitz claims accord with, 711.
Zoophytes, not monstrous, but orderly
productions, 713.
INDEX (J
TO THE XOTES, ADDITIONS. AND CORRECTIONS
A posteriori knowledge, Leibnitz's
view of, 109, 227, 758 ; Kant's view
of, 109, 227, 758.
A priori knowledge, Leibnitz's view
of. 109, 227, 758 ; Kant's view of, 109,
227, 758.
Ab nniuersali ad particular?, is it ap
plicable always? 509; the principle,
De continents et contento, 5(>9.
Adelung, J. C1., " (resell, d. mensch,
Narrheit," (500, (501, (504, (!05.
Aerial vehicles of spirits, 380.
/Esehylus," Prometheus Vinctus," 389.
Agnosticism, 195.
Agreement or disagreement, Leibnit/
reduces Locke's enumeration of the
kinds of, 401.
Aimant, 1', Leibnitz writes upon, 740.
Abel, Niels Henrik, demonstrates the I Air, scholastic conception of, 740.
impossibility of reducing by radi- i Aix, its derivation, 301.
cals general equations higher than
the fourth degree, 571.
Absinthium, 765.
Absolute, belongs to reason, .158 ; how
we become acquainted with it, 158.
Albertns Magnus, 278, 381 ; unjustly
suspected of magical practices, 278.
Albinus Flaecus, instructor of Charle
magne, 54(5 ; *' Opera," 54(i.
Alcuin, see Albinus Flacetis.
Abstraction, to what extent a depart- | Aldrich, Henry, " Artis Logic* Rudi-
ure from reality, 728.
Academie, des Inscriptions et Belles-
Lettres, 547 ; Francaise, 550 ; des
Sciences de Paris, 5"0.
Academy, Old, 518.
Accidentia, 455.
" Accidents and abstracts," their con
sideration develops the differences
between the theories of Locke and
Leibnit/, 749.
'• Acroamatic," the epithet explained,
42. 272. 724.
'• Acta Cnncil. Reg., "581.
" Acta Eruditoruni," (5, 14, 101, 174,
227. 421. 434, 481, 502, 511, 670,
Acts 17: 2S, 15:;.
Adam as a symbol in Boehme's philos
ophy, 298.
Adams, F., "The Genuine Works of
Hippocrates," 47b'.
Adamson, on Gassendi, 421.
menta," 456, 7<!(!, 7(59.
Alexander of Aphrodisias, 581.
Alexander the Great, 531 i.
Alexandrists, 581.
Allbwelthpif, 732.
Alliot, Jean Baptiste, bis " Traite du
cancer," 352 ; — Pierre, his " Theses
medic* de molu sanguinis circu-
lato," 352; his '• Epistola de cancro
apparente," 352; his " Xuntius pro-
fligati sine ferro et igne carcino-
rnatis." 352.
I Allman, G. J., " Greek Geometry from
Tlialcs to Euclid," 108. 4(5:1, 475, 527 ;
" Pythagorean Geometry," 475.
j Alsted. .1. H., 311. 398: his " Encyclo-
p*dia," 311, 3(5:!; and '• Systema
logica* harmonicum," 398.
{ Amadis de Ganla, 39!).
j Amare (diligere) defined, 750.
' Amor non mercenarius, 750.
831
LL1BM1Z\S CK1TIQI K OF LOCK:-:
" Anabaptisticum et enthusiasticum
Pantheon," 601.
Anabaptists, 602.
Analogy, the class of phenomena in
which it affords probable conclu
sions, 549; its conclusions are only
rational hypotheses since not founded
on complete inductions or mathe
matical data, 550; the rationality of
a conclusion drawn from, on what
it depends, 550.
Analysis, how explained by Pappus,
521.
Anaxagoras, 65, 519.
Anaximenes, 519.
Andrada. Diego Payva d', theologian,
592: on salvability of heathen, 592;
his " Orthodoxarum explication um
de religionis Christiana; capitibus
libri X.," 592; his " Defensio Tri-
dentinae fidei," etc., 592; maintains
a controversy with Chemnitz, 592.
Andrews, E. B., " Institutes of General
History," 453; on quart us modus,
455.
Andriae, Tobias, 633.
'Ai^/cSora, Td, of Procopius, 542.
Aniina mundi, 382.
Animalcula within animalcula, 722.
" Animant," its meaning, 125 ; its per
haps preferable variant, 125, 740.
Anselm, founder of Christian Scholas
ticism, 502; his "Monologium,"502;
his " Cur Deus Homo," 502, 503; his
" Proslogium," 502, 503; his " Liber
apologeticus," 503; his ontologieal
argument for existence of God, 503;
several of his tractates which have
been translated, 503.
Antimony, 324.
Antipodes, 444.
Anti-Ramists, 408.
Antisthenes, 518; taught that virtue
only is good, 518; a list of his writ
ings, 519.
Antitypy, avrirvirla, 721, 722.
Antoninus, Marcus Aurelius, 495 ; his
" Meditations," or " Thoughts," 495.
Apagogical demonstration, 491.
Apes have organs of speech, 286.
Apodeictic syllogism, 565.
, 564.
Apollonius of Perga, 108 ; his " Treatise
on Conies," 108, 465.
Apostolici Regiminis, the papal decree
of, 581.
Appuleius, 455.
Apuleius, 243; his " Metamorphoses "
summarized, 243.
Aquaviva, Claudius, 619: his "Ratio
Studiorum," 619.
Aquinas, Thomas, 230, 503 ; his
"Summa Theologia', 230, 4l>6, 503,
729; on species, 381; a realist, 382;
criticises ontological argument for
existence of God, 503; his ''Contra
Gentiles," 503 ;" censured by Spinoza,
504; on "ignis infernus," 730; op
posed by Lessius, 749; his use of
" phantasm," 769.
Arbor Porphi/riana, 322 ; priedi ca
me ntalis, 322 ; prsef.licabilis, 322.
Archaeus, 67, 382, 733.
Archilaus, a physicist, 519.
Archimedes, 93, 108; greatest Greek
mathematician, 414 ; the first mathe
matical engineer, 414; best edition
of his works, 414.
Argenteus, Codex, 295.
Argot, 293.
" Argument," as applied to middle
term, 481.
Argument, topical. 564.
Argumentum, simplex, 398 ; eow-
plexum, 398.
Ariosto, his " Orlando Furioso," 399.
Aristippus, 518; made pleasure end of
life, 518: his definition of pleasure,
518; his writings enumerated, 518;
his philosophy discussed, 518.
Aristotle, 66 ; his " Nicomachean
Ethics," IK!, 180, 285, 321, 752, 753;
his "Physics" (&VO-IKTJ 'A/cp6a<ris)»
156, 157, 174, 272, 320, 321, 750, 751 ;
his " Metaphysica," 156, 174. 311,
320, 495. 498, 751 ; his definition of
probability, 214; his "Rhetoric,"
214; his "Analytica Priora,"214.636;
his "Meteorologica," 277; on Milky
Way, 277 ; his " De Anima," 281, 321,
724, 760, 763 : his " De Interpreta-
tione," 281, 291, 452, 763; on man as
a social being, 285: his " Politeia,"
285, 28(5, 482; his "Categories,"
INDEX C
833
311: on genus and difference, 312;
Leibnitz's defence of, from Locke's
strictures, 312; his "Topica," 312,
418, 5(54, 565, 6:36; on motion, 320,
321 : on light, 321 ; oixria, how used
by, 349; his vovs iradijTiKfa, 381; his
vovs TTOLTJTIKOS, 381 ; on knowledge
as dependent on things previously
known, 413; his "Analytica Posteri-
ora," 413,636; Leibnitz's opinion of,
4KJ : on ej>5o£a, 418; his use of tdiov,
455 ; his limit to scientific considera
tion, 488; his Kado\ov irpuTov, 488;
his Trepi 2,o<f>icrTiKui> >EX^7xwi'5 519;
on a pupil's prior and provisional
faith in his teacher, 519; his defini-
tion of " topical argument," 564: is
" unsaved," 59,3 : on mind as an
unwritten tablet, 726: his " Magna
Moralia," 752,753; his " Eudemean
Ethics," 753; on will and freedom,
753 ; on soul as not indifferent to
every kind of matter, 760 : on mid
dle term, 770.
Arminians, the later, 733.
Arminius, James, 72.
Arnauld, Antoine, 463, 530 ; Leibnitz's
letter to, 101 ; on Descartes' funda
mental dictum, 410: " (Euvres,"
463 ; "La Logique ou L'Art Penser,"
464: his controversy with Holden,
617 : — Simon, Marquis de Pomponne,
605.
Arnold, Gottfried, " Kirchen und
Ketzerhistorie," 600, 602.
Arrian, reporter of Epictetus' talk,
496.
Art schools, Leibnitz favors their
founding, 628.
Aries liberates, 628.
Askath Rachel, 242.
Assassins, the, 197.
Association, Law of, its germ in Leib
nitz's teaching, 764.
" Assurance Magazine," 540.
Atomism, Leibnitz early defends, 723.
Atoms, an additional argument against,
656; non-existent, 722 ; why rejected
by Leibnitz, 727.
Aubery, see Maurier.
Augustinus, Aurelius. anticipated Des
cartes' fundamental dictum, 410 ;
his " Soliloquium," 410, 516; ground
of his philosophy, 516 ; his "De
Beata Vita," 516; " De Trinitate,"
516, 589 ; " De Vera Religione," 516 ;
literature illustrative of philosophy
of, 516 ; " De Ideis," 516, 594 ; on con
sciousness involving in itself the
idea of God, 575 ; "De peccatorum
meritis et remissione et de Bap-
tismo parvulorum," 594; "De pec-
cato originali," 594 ; " Encheiridiou
ad Laurent.," 594 ; " De nupliis et
concupiscentia," 594; "Contra Juli-
anum Pelagianum," 594 ; "Contra
duas epistolas Pelagii," 594 ; teaches
that babes dying unbaptized are in
some sort damned, 594; his "De
Civitate Dei," 594, 729 ; his "Opera,"
(516; on a future material fire, 729.
Augustus I., alchemist, 339.
Authority, Leibnitz opposes blind sub
mission to, 579.
Aventinus, Johann Thurmayr, his
" Annales Boiorum," 54(5.
Averroes, 581.
Averroists, 581, 590, 732 ; related to
Mystics and Quietists, 728.
Axioms, their demonstration, 463;
should they be lessened ? 770.
Baader, von, his relation to Boehnie,
298.
Bachet de Merzeriac, his edition of
" Diophantus," 571.
Bacon, Francis, 591 ; on Idohi Furi,
30(5; his " Xovum Organum," 306 .
his " De Augmentis," 30(i ; Leibnitz's
estimate of, 30(5 : editions of his
works, 306, 307 : Spinoza's refer
ence to, 526: his " Spiritus," 684;
— Roger, 278.
Bagheminus, 632.
Baitar, Ibn al, 371 ; greatest of Ara
bian botanists, 371 ; his alphabetical
list of simples, 371; his " Ma-teria
Medica," 371 : sources of informa
tion concerning, 371.
Balaam, Leibnitz's essay on, 767.
Bancroft, "History of United States
of America," 599, 773.
Barantola, 737.
Barbeyrac, Jean, 286; translator of
834
LEIBNITZ'S CRITIQUE OF LOCKE
the "De Jure" of Grotius, 28(5;
translator of Pufendorf, 436.
Barclay, Robert, 55)9; his "Apology for
the True Christian Divinity." 599.
Bardeen, C. W., editor of Coinenius,
4(56.
Baruer, Jacob. 487; his " Prodromus
Sennerti novi," 487.
Basilius, Valentinus, his " Sehluss-Ke-
den," 324; his "Chymische Schrif-
ten," 324.
Basnage de Beauval, his (l Histoire
des Oavrages des Savants," 50,
507; his "Histoire critique de la
Republique des Lettres," 508.
Baudoinr Jean, his " L'homme dans
la Lune." 342.
Bauhin, Jean, a founder of modern
botany, his " De Plantis Absinthii
nomen habentibus." 308: his " His-
toria universalis Plantarum," "09:
— Gaspard. 308.
Baumgarten, H, " Ueber Sleidanus
Leben und Brief wechsel," 114.
Baumgarten, Martin, his " Travels
through Egypt, Arabia, and Pales
tine," 89, 735.
Bayle, Pierre, 507, 727 ; his " Xouvelles
de la Republique des Lettres," 50 ;
his " Dictionnaire historique et cri
tique." 278. 441. 507. 531, 601,604,727 ;
his ••Dictionary'' article " Rora-
rius." 66,507, 50S.
piresdu soleil," 228, and also " de la
lune," 228.
Berkeley, 772; his ''Essay towards a
new Theory of Vision," 747.
Berkum, H. van, his " De Labadie et
de Labadisten," 602.
j Bernays, his "Die Dialoge des Aris-
toteles," 272; " Der Chronik des
Sulpicius Severus," 345.
Bernhardt, E., his " Vulfila oder die
gotische Bibel," 296.
Bernier, Francois, " Abrege de la Phi
losophic de Gassendi," 64, 730.
Beruouilli, James, 213.
Beverwyck, Jan van, physician, 621;
simplifies prescriptions, 624 ; his
•' Idea medicinae veterum," 624.
Beyerlinck, Laurent, his " Theatrum
vit* human JP," (522.
Bibliotheca, Maxima Veterum Patrum,
444 ; Sacra, 50:'.
Bibliotheque Universelle, see Leclcrc.
Biel, 382.
Bigg, his "Christian Platonists of
Alexandria." 729.
Black ie, John Stuart, his " Four
Phases of Morals," 598.
Blarkburne. Francis, his "Historical
View of Controversy concerning an
Intermediate State," 775.
Blasius, Gerard, 351.
Bochart. Samuel, 302; on the connec
tion of languages, 302 1
Baynes, Thomas Spencer, translates j Bodin. Jean, the earliest systemati/er
the "La Logique ou L'Art de Pen- I of Political Economy, 6i8.
ser," or the Port Royal Logic, 14, 4(54. Boeder, Johann Heinrich, C50.
Bears, child of the, 344. i Body, in Cartesian sense. 348
Becan, John (Van Gorp), 303; his
'• Origines Antwerpianae," 303; on
the original language, 303; on the
site of Paradise, 303.
Bede, the Venerable, his "Ecclesias
tical History," 295.
Regriff, 330.
Begri.ffliche Wesen , 31 1 .
Beings, notional or conceptional, 311.
Bellarmin, his "De Purgatorio," 730.
Bellay, Cardinal du, 114.
Benn, Alfred William, his " Greek
Philosophers," 108, 156, 421. 576, 724.
Bergerac, Cyrano de, 228, 399 : his
" Histoire comique des e'tats et em-
invisi-
wliat?
~>(\ ; its
ble, why l>elieved in, 721
721,722: mere phenomena,
action phenomenal, 756.
Boehme, Jacob, 29S, 732: a Protestant
theosophist, 298: the first charac
teristically German philosopher, 298 ;
forerunner of Leibnitz's metaphysic,
298; his "Das dreyfache Leben,"
298: his " Sammtliche Werke," 298;
Leibnitz's estimate of, 298, 765: in
fluences Quirin Kuhlmann, 601.
Boethius, 455, 724.
Bohl, S::muel, his researches into the
Massoretic system of Hebrew mark
ings, 366.
INDftX C
Coiardo, Matteo Maria, Count of
Smndiano, his '' Orlando Innanlo-
rato," 31)8.
Hoileau-Despreaux, Nicolas, his "Sat
ires,'1 97, 730.
B.»lsec, Jerome Hermes, advocates
Pelagian views in Geneva, 545 : cen
sured by Calvin, 545; imprisoned by
Senate. 515; pursued by Calvin's
hostility to Bern, 545; conceives
hatred to his persecutors, 545 : writes
his " Histoire de la Vie, Moeurs,
Actes, Doctrines et Mort de Jean
Calvin," 545, ibid, new ed., 773 ; and
his " Histoire de la Vie, Moeurs, Doc-
irines et Deportement de Theodore
de Beze," 545.
Boniface, apostle to the Germans, 443;
his "Opera quae extant," 443; his
controversy with Virgil, 444; Pope
Zachary's letter to, 444.
Bonino, G. G., " Biografia medica
piemontese," 521.
Bonitz.his " Index Aristotelicus," 383.
Bnnosus. described by Vopiscus, 7(51.
Borelli, Giovanni Alfonso, 676.
Borgia, Francisco, 754.
Boscovich. 772.
Bosses, Des, Leibnitz's correspondence
with, in which is contained clearest
exposition of the Monadology, 101.
Bossuet, Jacques Benigne, his corre
spondence with Leibnitz, 531.
Bouhours, Dominique, his " Maniere
de bien penser dans les ouvrages
d'esprit," 141: Leibnitz's estimate
of, 748.
Bonillier, his "Histoire de la Philo
sophic Cartesienne," 421; his
"Eloges de Fontenelle," 550.
Boulliau, Isniael, his " Ad a^tronomos
monita duo," 573; his " De lineis
spiralibus," 573; his theory concern
ing variable stars, 573.
Bouquet, his " Rerum Gall, et Franc,
scriptores," 99; his " Rec. Hist.
( iaules," 737.
Bourignon, Antoinette, 599, 728; her
" Traite de 1'aveugleinent des
hommes," 599; her " La lumiere du
monde," 599; her " De la lumiere
ne'e en tenebres," 599; Kuhlmann
relations with. 601 ; Labadie's rela
tions with, h'02; Lacoste's revulsion
of feeling towards, 604 ; Leibnitz re
fers to, 728.
Boutan (Bhutan), 73<>.
Bowne, Borden P., his '' Metaphysics,"
470.
Boyle, Robert, 324; discovers law of
compressibility of gases, 324 ; a
founder of the Royal Society,
England. 324; his "Of Absolute
Rest in Bodies," 324; his works,
324, 726.
Brachet, his " Historical Grammar of
the French," 2.»4.
Bradley, F. H., his "Principles of
Logic," 214, 764.
Brambach, W., his " G. W. Leibniz,
Verfasser der Histoire de Bileam,"
767.
Braunfels, his " Kritischer Versnch
iiber Amadis," 399.
Brautigam, L., his "Leibniz und
Herbart iiber die Freiheit d. menschl.
Willens/' 752.
Bremont d'Ars corrects a mistake of
Moreri's, 539.
Britannica, Encyclopedia, 67, 68, i!44,
294, 311, 399, 421, 425, 475, 542. 5'2,
573, 598.
Brocardica, 486.
i Brooke, Stopford A., his "History of
Early English Literature," 295.
| Briicker, " Historia Philos.," 278, 60 i.
Bruno, Giordano, his use of term
"monad,'' 101: his "Delia Causa,"
732.
Bryce, James, his article " Procopius,"
in " Encyclop. Britannica," 542.
! Bucer, Martin, 114.
Buddeus, Johann Franz, 713.
Bulletin des Sciences Mathematiques,
768.
Buratini, his flying machine, 749.
I Burckhard, his "Historia Bibliotheca;
Augusta','' 2i2.
" Burgoldensis," an a.nagram. 650.
Buridan, John, his " Questiones Etlii-
corum Aristotelis," 116; his view of
liberty, 116: the illustration of the
fatally indifferent ass not of his
authorship. 11(5.
886
LEIBNITZ'S CRITIQUE OF LOCKE
Ceulen, Ludolph van, his "Van de
Circkel," 734 ; his " De arithmetische
en geometrische fondamenten," 734 :
his " Zetemata," 734 ; computes ratio
of diameter of circle to its circum
ference to thirty-five places of deci
mals, 734.
Chabre'e of Geneva, his '• Sciagraphia,"
Burnet, Thomas, his correspondence
with Leibnitz, 6, 478.
Burridge of Dublin, the Latin trans
lator of the " Nouveaux Essais," 37.
Butler, Nicholas Murray, his "Great
Educators," 619.
Credmon, his Anglo-Saxon Paraphrase
of Scripture, 21)5.
Caird, E., his article " Cartesianism," j Changeling, 447 : " Chaungelings,"770.
in " Encyclop. Britannica," 421; his | " Characteristic, a General," 292, 37.",
" Philosophy of Kant," 319, 332, 503 ; j 437.
his "Critical Philosophy of Kant," j Chastel, P. L., edits Bolsec's Vie dc
503. Calvin, 773.
Caird, John, his " Introduction to the j Chauvin, Stephen, his " Lexicon Philo-
Philosophy of Religion," 274. sophicum," 3(33.
Calculus of Infinitesimals, controversy Chemnitz, Martin, greatest of imnie-
regarding its discoverer, 573; of
Probabilities, 213.
Calendar, Gregorian, 424.
Calixtus, George, 587.
Campanella, Tommaso, 67, 640, 732.
Camper, Peter, his " Natuurkundige
Verhandelingen," 286; on the lan
guage of apes, 286.
Capella, Marcianus, 455.
Capes, his " Stoicism," 49(5.
Cardano, Girolamo, 67. 106, 566, 572;
his "De Subtilitate," 106; on the
spiritusfamiliaris, 730.
Carlo witz, peace of, 259.
Carrington, his "History of the Life
and Death of Oliver Cromwell," 543.
Casati and Christiana of Sweden, 751.
Casaubon, Isaac, 47S.
Casimir, John, 344.
Casuistry to be supplanted by logic of
probabilities, 213.
Categories of Kant, arise from Leib
nitz's doctrine, 741.
Cats, Jacob, Dutch poet. 624.
Cause, primal, its signification, 757 :
Hume upon, 757.
Causes, efficient, depend upon final,
721.
Cebes of Thebes, 436; his reputed
Ilti/a^ " spurious," 43ii.
Century Dictionary, (57.
"Certain author, a," 738.
Certainty, its kinds, metaphysical,
4(>2; moral or physical, 462.
Cervantes, "Don Quixote," 321.
diately post-Lutheran theologians,
592 ; his " Examen Concilii Triden-
tini," 592; his "Loci Theologici,"
592.
Cherler, collaborator with the Bauhins,
309.
Cheruel, his " Dictionnaire des Insti
tutions Francaises," 757.
" Chevauchier," 757.
" Chimerisme," Leibnitz defines, 762.
Chinese, their dictionaries, 394.
Xwpto-^tos, the Aristotelian, 756.
Christianity consists in its ethical con
tent, 607.'
Chrocus, the Vandal. 99.
Chronicles, II., 6: 18, 158.
Chrysostom, John, on Greek culture,
591 ; his hopeful views of humanity,
591.
Cicero, his " De officiis," 192. 261, 765 ;
"De Finibus," 192. 272, 765: " De
Oratore," 214, 765: " Qiuestiones
Tusculana?," 264: "Ad Atticum,"
327 ; " De Legibus," 500 : " Topica."
766.
Circle-quadrature, historical sketch of,
425: Leibnitz's relation to the prob
lem of, 425.
Cisner, Nicolas, 546.
Clarke, John, his translation of
"Jacobi Rohaulti Physica," 233;
— Samuel, his notes on "Rohaulti
Physica," 23:5.
Class, G., his " Der Leibnizsche Deter-
minismus," 752.
INDEX C
Clauberg, Jean, 303, 304; Leibnitz's
opinion of, 304: his " De Conjunc-
tione animse et corporis humani
seriptum," 303 ; his " Ontosophia, de
cognitione Dei et uostri," 303.
Clavius, Christopher, the Euclid of
the sixteenth century, 424; assists
in correcting the calendar, 424 ; his
'•Euclidis elementa," 424; his
'•Sinus lineae tangentis," 424; his
" Romani Calendarii explicatio,"
424 : edits " Photismi " of Maurolico,
442.
" Clelie, Histoire Romaine," 223.
Clement of Alexandria, 575 ; his " Stro-
mata." 591; on "light of nature,"
591 ; on purgatorial fire, 729.
Clerc, Jean le, his " Bibliotheque uni-
verselle et historique," 723; his" Bi
bliotheque choisie," 723 ; his " Biblio
theque ancienne et moderne," 723;
bis abstract of Locke's essay, 728.
Clericus. J., 733.
Clerke, Gilbert, 634.
Clerselier, Claude, his " Les Lettres de
Descartes," 633.
Clichtoveus, " Elucidatorium Eccle-
siasticum," 603.
Cloelia, the Roman maiden, 223.
Co-divisions, 337.
Cock, made into Platonic man, 385.
Codex Justinian, see Corpus, Juris;
— Ai'yenteus, 295.
Collateral distributions, 337.
Collectio Librorum Juris Aiitejusti-
HtiDti, edited by Krueger, Mommsen,
and Studemund, 70(5, 769, 771, 773.
Collio, Francesco, 593 : his views on
salvabilityof pagans, 593; held Aris
totle " unsaved," 593; his " De ani-
mabus paganorum," 593.
Cornelius. John Amos, a writer on
pedagogy, 466: his "Opera didac-
tica," 46(3: publishes his " Physicae
ad lumen Diviiium reformatae synop
sis," 466; estimates and biographies
of. 4(i6.
Compressibility explained by Leibnitz,
723.
" Comptes Rendus." 425.
Conarion, why the suggested seat of
soul? 758.
I Concepts, the hypostatizing of, a large
source of error, 30(3.
Conceptio, concepttts, 330.
i "Conclusion, that the, cannot contain
more than the premises," variously
expressed, 515.
Connaway (Con way) , Countess of, 732 ;
her "Opuscula philosophica," 732.
i Connotations, intrinsic, 738.
Conring, Hermann, his vast erudition,
520; his "Opera omnia," 520; his
voluminous correspondence with
Leibnitz, 520 ; taught Oldenbur-
gerus, 650.
i Consciousness, E. G. Robinson on, 741.
" Consequent, greatness of the," Janet
explains the phrase, 756.
"Contemporary Review," 542.
\ Continens et contention, 569.
: Continuity, Law of, 334, 509, 712.
Contradictory ideas, their combina
tion under one notion how detected,
354.
i Copernicus, Nicolas, 419 ; his " De
orbium crelestium revolutionibus,"
419.
j Corban, .1?-^, 327.
j Corinthians', I., 2:9, 200, 583.
i Corneille, Thomas, 536.
i " Corpus Juris Civilis," Mommsen and
Paris editions, 241, 329, 434, 486, 487,
492, 497, 534, 735, 759, 76(3, 769, 770,
771, 773.
| Corruptio optimi pessima, 482.
j Coste, Pierre, 169 ; " Essai philoso-
phique concernant 1'Entendement
humain — par M. Locke," xiv, 4,
7; as translator of Locke, 101, 727;
is sometimes clearer than Locke,
103.
Cousin, his " (Euvres de Descartes,"
731, 748, 749, 758, 759, 770, 773, 774.
1 Creation, Leibnitz's view of, -'24 :
Locke's view of, 771.
"Credibility, motives of," defined by
Leibnitz, 774.
Cremer, his " Biblico-Theological Lexi
con of New Testament Greek,"
289.
Cromwell, 543.
Crown, laurel, in surgery, 520.
" Crusca, La," 18.
LEIBNIT/'S CRITIQUE OF LOCKE
Cud worth, Ralph, 6f> : his "True In
tellectual System of the Universe,"
(55, 730 ; editions of his works, (if).
Cynic School, 518.
Cyrenaic School, 518.
Dahn, F., his " Profcopius von Case-
rea," 542.
Daial-Kirbal, 197.
Duis, 197.
Dalgarno. George, 292; his "Ars Sig-
horum," 292; inventor of manual
alphabet, 292.
Damnatio levissima omnium, the fate
of infants dying unbaptized, 594.
Dangicourt, a correspondent of Leib
nitz, 101.
Darapti may become Darii, 568.
Darwin, C., his "Origin of Species,"
345.
Dasypodius, Conrad, 404; his "Ana
lysis Geometries," 404.
D'Aurnont, Louis Marie- Victor, numis
matist. 547.
Debidour, M., his " Thesis" in defence
of Empress Theodora, 542.
Decahedron, a nominal definition, 317.
Definition, according to Aristotle, 312;
Leibnitz's vindication of Aristotle's
rule concerning, 312; on the use of
loose, 313: Leibnitz's definition of
nominal, 317, 398 ; of real, 317 ; of ge
netic, 317: of causal, 317; Leibnitz
defines analytically, 318.
Delecluse,590.
Delbruck, B., his " Eiuleitung in das
Sprachstudium," 292.
Delphin classics, 605.
Democritus,b'4 : on Milky Way, 277.
Demoivre, his "Doctrine of chances,
or method of calculating the proba
bilities of events at play," 213.
" Demons or goblins," 730.
Demonstration, philosophical, reduced
to syllogism and prosyllogism, 404;
none according to Leibnitz in Aris
totle and Plato, 410; proposal to ex
tend its bounds, 437; direct, 491:
what it appeals to, 766.
Denores, Jason, 636.
Desargues, Gaspard, geometer and
engineer. 137.
Descartes, Rene, (54, 348; friend of
Digby, 83 ; denies vacuum, 127 ; his
"Principia Philosophic," 127, 128,
148, 230, 483, 484, 502, 552, 602, 613,
727, 7:34, 741, 748, 749 ; his letter to
Samuel Clarke, 127; his letter to Mer-
seime, 137,759; his " Meditationes
de Prinia Philosophia," 229, 502, 731 ;
his " Dioptrica," 230 : his " Passiones
Animse,"230; his theory concerning
the Pineal Gland, 2:30, 758; friend
of Froidmont, 234; his "Epistles,"
348 ; his remarks on the programme
of Regius, 348; explodes "inten
tional species," 382; his opinion of
Frenicle, 393 ; his preliminary diction
anticipated, 410; corresponds with
Hardy and Fermat, 466; on the
argument for the existence of God,
502; " Disco urs sur la methode pour
bien conduire sa raison, etc.," 502,
534 ; his theory of vortices, 552, (513 ;
his theory of matter of the first and
second elements, (513; avoids his
" rock of velocity," 659 : Reponses to
" Objectiones quintse " of Gassendi,
731; his "Regular ad directionem
iugenii," 734; his Platonic Aris
totelian dualism, 757 ; letter to
Meissonier, 758.
Deschales, Claude Francois Milliet ,(576.
Deusing, Anton, his " De vero system-
ate mundi," 632.
De Vise, 438.
Dewey, John, his "Leibniz's New
Essays, a Critical Exposition," x\ .,
17, 128. 129, 131, 317, 319, 336, 3(53.
Dialectic syllogism, 564.
Dieckhoff, his "Leibniz Stellung zur
Offenbarung," 770.
Dietz, his " Analecta Medica," 371.
Diez, Friedrich Christian, founder of
Romance philology, 294; his " Altro-
manische Sprachdenkmsiler," 294.
Difference, actual, in what it consists,
761.
Digby, Sir Kenelm, his "Treatise on
the Nature of Bodies, 83; " Demon-
stratio immortalitatis animae ratio-
nalis,"735; on " vacuum," 774.
Digesta, see Corpus Juris Civilis,
Dillmann, Edward, his " Eine neue
INDEX C
839
Darstellung der Leibnizischen Mon-
adlehre auf Grund der Quelleri," 102,
180, 2'25, 349.
Diogenes of Apollonia, 519.
Diogenes the Cynic, and " the man of
Plato," 385.
Diogenes Laertius, his " Lives of the
Philosophers," 379, 385, 518, 519.
Diophantus, 571 ; his " Arithmeticorum
libri sex," 571.
Dioscorides, 371.
Direct demonstration, 491.
Disamis, how it may be derived from
Barbara, 407.
%< Distinguished sufficiently," 727.
Divini, Eustachio, 613; his alleged
controversy with Huygens, in "Sys-
tema Saturnium," (513, 614.
Doctor juris utrinsque, 758.
Dods, M., translator of Augustine, 516,
729.
Dominis, M. Ant. de, 442; his " De
Republica ecclesiastica," 443; his
" De radiis visus et lucis in vitris
perspectivis et iride," 443.
" Don Juan ou le Festiu de Pierre " of
Moliere, 536.
Don Quixote, 321, 706.
"Donation." the so-called, "of Con-
stantine," exposed by Valla, 415.
Dorner, I. A., his " System der Christ-
lichen Glaubenslehre," 249, 503.
" Double truth," the doctrine of, 581.
Drabitius, Nicolas, an enthusiast, 604 ;
stirs George of Transylvania to an
unsuccessful movement against Po
land, 005 ; burned at the stake, 605.
Draud, George, 626; his "Bibliotheca
Classica," 620.
Dreier. Christian (Peter), 635.
Drobisch, Moritz Wilhelm, 337; on
''collateral distributions," 337.
Du Hamel, Jean Baptiste, 634.
Duchesne, Andrew, "46; his "Hist.
Franc. Script.," 737.
Duncan. G. W., his translation, "The
Philosophical Works of Leibnitz,"
xiii, 3, 14, 15, 18, 68, 101, 127, 128,
131, i:u5, 154, 167, 174, 239, 317, 332,
34(1, 363, 381, .".83, 420, 421, 470, 502,
504, 511, 553, 722, 723, 737, 748, 749,
750, "51, 775.
Duns Scotus, see Scotus.
Dupin, Louis Ellies ; his " Bibliotheque
Universelle des Auteurs ecclesias-
tiques," 418, 593, 617.
Durandus, 382.
Durrius, Johann Conrad, 636.
Dutens, his " Leibnitii Opera Omnia,"
101, 290, 292, 294, 295, 298, 302, 304,
306, 311, 317, 318, 324, 333, 337, 344,
345, 346, 381, 382, 383, 394, 415, 417,
420, 425, 434, 435, 436, 438, 443, 450,
451, 465, 466, 478, 484, 486, 495, 491),
502, 504, 508, 511, 520, 532, 539, 544,
546, 550, 551, 552, 553, 554, 561, 573,
579, 590, 591, 592, 595, 600, 606, 626,
631, 638, 649, 683, 70(5, 733, 737, 748,
750, 761, 766, 767, 768, 774.
Dynamic Idealism, that of Leibnitz,
723.
Dyoor, 341.
Eccard, 304.
E?5os, 349.
Egnazio, Giovanni Battista, 610; his
"De Romanis principibus," 610.
Elaterium, 655.
Eleatic School, 93.
j Elementargeister, 730.
j Elements, the, according to Empedo-
cles, Plato, and Aristotle, 362.
I Elimination, a method of, 413.
[ Eloqes of the French Academicians,
550.
Elwes, R. H. M., translator of Spinoza,
192.
Emotion and passion, not distinguished
by Leibnitz and Locke, 751.
Empedocles, 302; his four elements,
362.
" End organs " of nerves, 739.
Ende, Francis Van der. 345.
Endoxa, in Aristotle, 418.
Enthyrneme, 481.
Entia rationlx. 311, 759.
'ETrixeipr)/ui.a, what? 565.
Epictetus, 496; his Aiar/>t)3a<, 490.
Epicurus, 126, 421 ; literature of his
life and philosophy, 421.
Epigram, its nature, 481.
Episcopius, Simon, 179,733; his " De
libero arbitrio," 179.
Equations: " ordinary " or algebraic,
840
LEIBNITZ'S CRITIQUE OF LOCKE
425; "extraordinary" or transcen
dental, 425; reduction of, 571.
Erasmus, 591, 592.
Eratosthenes, 93.
Erdmann, J. E., his " Leibnitii Opera
Philosophiea," xii, 3, 13, 14, 15, 16,
19, 42, 46, 47, 49, 50, 52, 53, 5(J, 58,
62, 63, 73, 80, 87, 89, 90, 91, 97, 101,
118. 119, 120, 121, 123, 125, 127, 128,
131, 136, 147, 150, 154, 155, 159, 167,
174, 180, 185, 203, 204, 205, 210, 211,
213, 218, 219, 220, 225, 227, 229, 239,
240, 245, 246, 249, 251, 254, 257, 259,
2(51, 2(53, 267, 270, 272, 273, 274, 275,
282, 28,°,, 284, 2<!0, 293, 300, 301, 306,
310, 314. 316, 317, 318, 319, 321, 323,
326, 332, 333, 334, 341, 346, 349, 363,
376, 37(.», 381, 382, 383, 386, 405, 412,
414, 419, 420, 421, 434, 436, 437, 450,
451, 460, 466, 476, 496, 497, 502, 504,
506, 508, 511, 513, 537, 539, 548,
551, 553. 561, 580, 588, 631, 632, 635,
638. (544, 677. 687, 692, 693, 698, 705,
706, 717, 721, 727, 731, 735, 749, 750,
751, 752, 753. 7(5(5; " Grundriss d.
Gesch. d. Philos.," 67, 68, 129, 131,
278, 303, 590.
Erkenntnisslehre, 319, 633.
Ennerins, F. Z., his " Hippocratis et
aliorum medicorum reliquae," 476.
Erpenius, 287.
Esoteric teachings, 272.
" Esprit." 28. [768.
"Ethereal vehicles" for spirits, 380,
Ethics, its truths founded in natural
theology. 45)6.
Eucharist, Lutheran view of. 611.
Eucken, Rudolph, his "Fundamental
Concepts of Modern Philosophical
Thought," 227, 239 : his " Gesch. und
Kritik der Grundbegriffe der Gegeu-
wart," 75S : his " Die Grundhegriffe
der Gegenwart historisch und kri-
tisch ent \viekelt," 758.
Euclid of Alexandria, 93 : his response
to Ptolemy, 93 ; commentators upon,
108; his Elements reduced to syllo
gisms, 769; — of Megara, 93.
Euler, Leonard, 393.
Eutocius of Ascalonita, 4(55.
Evolution, theory of, hinted at by
Leibnitz, 347.
"Ex professo," 739.
"Exception, some," 728.
Exclusion, a method of, 413.
Existence, what? 401.
Existence of God, Descartes on, 502;
Spinoza on, 502; Leibnitz on, 502;
Anselmic argument for, 503.
| Exoteric teachings, 272.
j Experience, its incompetency, 725.
" Experieutia," its use among Scho
lastics, 724.
Eye, "accommodation" of the, 228:
men with only one, 389; Maurolico
upon the, 442.
Fabri, Honore'. 586 ; disputes with Sen-
nert upon the immateriality of the
souls of animals, 488 ; his " Synopsis
Geometrica," 586: his " Physica seu
scientia rerum corporearum," 586;
his " Summula Theologian," 58(5 : as
sists Divini in the controversy with
Huygens. (514.
Fabricius, John Lewis, 102; saves the
Heidelberg archives, 102: his " Apo
logise generis human! contra calum-
niam Atheism!," 102; letter to Spi
noza, 723.
"Factum, in," 486.
^ctfTCKrta, (f>dvra(rfj,a, 7(59.
Farrar, F. \V., his "Seekers after
God," 49(5.
Fedais, the devoted ones, 197.
Feder. " Commercii epistolici Leibni-
tiani," 728.
Feeling, defined, 736; and ideas, their
relations, 754.
Felden, Johannes, 636.
Feller, his " Otium Hanoveranum."
595; edits "Miscellanea Leibniti-
aua," 443.
Felwinger, 635.
Fergil. St., 443.
Fermat, Pierre de. 213, 393, -165, 4li»>,
571 : his " De Maximis et Minimis,"
4(55 : " Opera Mathematica," 571.
Ferrari, Luigi, 572 ; resolves equations
of third and fourth degrees, 572.
Ferri, L., his "La Psicologia di P.
Pomponazzi," 581.
Ferro, Scipione del, 571 ; solves cubic
equations. 571.
INDEX C
841
Feyerabend, 626.
Figmenta mentis, 623.
Figure, syllogistic, the invention of
the Fourth, 408.
<bi\o<r6(j>r)tJi.a, what? 565.
Fiore, Antonio del, 571.
Fire, as <pp6vifjioi', 729.
Fischeiv Kuno, his " Gesch. d. neuern
Philos.," 218, 239, 363, 394, 421, 554,
579, 584, 629, 752 ; his " Descartes
and his School," 634.
Florentinus, 735.
Fludd, Robert, his " Philosophia Mo-
saica," 63, 730; his " Utr unique
Cosmi," 730.
Foerster und Koschwitz, their " Alt-
franzosisches Uebungsbuch," 294.
Fontenelle, Bernard le Bovier de, his
" Entretiens sur la pluralite des
inondes," 550; his " Eloge de Leib
niz," 550; his " Dialogues des
Morts,"551 ; " Doutes sur le systeme
physique des causes occasionelles,"
551.
Fontanier-Pellisson, Paul, 591 ; corre- |
sponds with Leibnitz, 591 ; his " His- |
toria 1'Academie Francaise," 591:1
his "Traite de 1'Eucharistie," 591; |
his " Reflexions sur les differends en j
matiere de religion," 591.
4>0pci, 321.
Force, primitive and derivative, 721. |
" Formalities," 569.
Forms, substantial, their origin, 349; j
Locke's view of, 349 ; Leibnitz's view |
of, 349.
Foucher de Careil, his " Lettres et i
opuscules inedits de Leibniz," xii, !
677, 748, 757; " Nouvelles lettres et
opuscules iuedits de Leibniz," xii,
101, 420, 496, 728, 748, 750, 752, 775;
his "QEuvres de Leibniz," xii, 532,
544, 591,592, 629, 737, 740, 757, 765;
his " Leibniz et Pierre le Grand,"
629.
Foucher, Simon, 420; ''the restorer
of the philosophy of the Academy,"
420: his "Critique de la Recherche
de la Verite," 420 : Malebranche crit
icises, 420 : his objections to doctrine j
of Pre-established Harmony, 420; his I
correspondence with Leibnitz, 420.
Fraser, Alexander Campbell, his
"Locke," 56, 747; his edition of
" Locke's Essay concerning Human
Understanding," 549, 728, 730, 735,
736, 737, 738, 747, 750, 755, 756, 760,
762, 763, 765, 766, 767, 768, 769, 770,
771, 772, 773 ; edits Berkeley, 747.
Free-will, Leibnitz's definition of, 752.
Freedom, ethical, distinguished from
free-will, 752.
Freigius, J., 311.
French version of Locke's Essay, 728.
Frenicle de Bessy, Bernard, a rapid
calculator, 393 ; his method, 393; his
"Traite des triangles et rectangles
in nombres," 393.
Frenicle, Nicolas, poet, 393.
Friedlein, G., edits works of Proclus,
108, 463.
Fries, G. F., his " Neue Kritik der
Vernunft," 764.
Frisch, Ch., edits Kepler's works, 123.
Froben, edits "Alcuini Opera," 546.
Froidmont (Fromont) Libert, 234; his
" Labyrinthus sive de compositione
continui," 234.
Fuchs, a botanist, 308.
Gabelentz and Loebe, their " Ulfilas,"
296.
Gaius, his " Elements of Roman Law,"
329, 434.
Galenus Claudius, 407; his " De usu
partium corporis humani," 407; his
" Opera omnia," 408 ; invents fourth
syllogistic figure, 408.
Galileo, paves the way to formulation
of law of gravitation, 440.
Ganzarini, Tito Giovanni, 51 Scandi-
anese, 399.
Garner, R. L., on language of mon
keys, 764 ; his " Speech of Monkeys,"
764.
Gass, W., his " Gesch. d. protestant-
ischen Dogmatik ihrem Zusammen-
hange mit der Theologie," 589, 595.
Gassendi, Pierre, 64, 65, 730; attacks
doctrine of intentional species, 382 ;
on Epicurus, 421 : his " Syntagma
Philosophicum," 421 ; " Gassendy,"
his Cinquieme Objections," 731; on
vacuum, 774.
842
LEIBNITZ'S CRITIQUE OF LOCKE
" Gaunersprache,'' its composition,
292.
Gaunilo, 502: his "Liber pro Insipi- !
enti," 503.
Gauss, Carl Friedrich, his " Theo- j
via niotus corporum enelestium," i
152.
Gander, L., his " (Euvres Poetiques |
d'Adam de St.-Victor," 603.
Gayard, his "Fragments relatifs a la
doctrine des Ismaelis," 197.
Genera and species, the philosophies
of Locke and Leibnitz most sharply
divergent on, 310.
"Generation, spontaneous," 346.
Genii, 52, 313.
Gergo, 293.
Gerhard, J., 587.
Gerhardt, Carl Immannel, " Die phi-
losophischen Schriften von G. W.
Leibniz," xii, 3, 10, 14, 15, 16, 2(5, 28,
41, 49, 50, 53, 55, 5(5, 57, 65, 66, 72, 73,
80, 87, 89, 90, 91, 97, 101, 105, 118,
119. 120, 121, 123, 125, 128, 131, 13(5,
147, 150, 154, 155,' 159, 174, 180, 184,
185, 199, 203, 204, 205, 210, 211, 213,
218, 219, 220, 225, 227, 229, 239, 245,
246, 249, 251, 254, 259, 2(53, 270, 272,
273, 274, 282, 283, 284, 292, 300, 301,
;K)6, 310, 311, 314, 316, 317, 319, 321,
323, 324, 330, 332, 333, 334, 341, 344,
346, 348, 349, 362, 363, 37(5, 379, 381,
382, 383, 386, 393, 394, 412, 420, 421,
425, 434, 4:56, 437, 4r>0, 451, 458, 460,
463, 466, 478, 4%, 497, 502, 504, 506,
508, 511, 513, 520, 521, 522, 532, 537,
518, 5.V2. 553, 561, 57(5, 580, 586, 588,
606, 623, 631, (533, 635, 638, 643, 644,
651,652, 653, 654, 655, 676, 677, 687,
692, 693, 697, 698, 699, 705, 70(5, 714,
715, 716, 717, 727, 728, 730, 731, 733,
741, 748, 749, 750, 751, 752, 753, 754,
755, 762, 766, 771 ; his " Einleitung," j
463; his " Sammlung des Pappus
siebentes and achtes Buch," 521;
"Leibniz, math. Schrift.," 573, 586,
6:54,657,659, 670, (571, (57(5, 677, 683,
684, 699, 733, 7:54, 7(57.
Gerland, E., his " Leibnizens and Huy-
gens Briefwechseln," 343.
Gesner, Conrad, " the German Pliny,"
626; makes the first attempt at
a literary encyclopedia, 626 ; his
'• Bibliotbeca Universalis," 626.
Gibbon, Edward, his "Decline and
Fall of the Roman Empire," 197.
345.
Gilbert, William, earliest methodical
experimentalist, 774: his " De mag-
riete rnagneticisque eorporibus," 771.
Glanvill, Joseph, 631.
Glass, Pliny on flexible, 316.
Gobien, Charles A., 104; his " Histoire
des Isles Mariannes," 104.
Goclen, R., 311 ; his " Lexicon philoso-
phicum," 311 ; his " Isagoge in Orga-
nnm Aristotelis," 311 : his regressive
sorites, 311 ; mediates between Aris
totle and Ramus, 408.
God, as place of things, 153; as actux
pur us, 159 ; omnipresence of, dyna
mic, 15!); his veracity, its place in
Cartesian system, 319; his existence
required by doctrine of monads, 3(53 ;
the scholastic distinction of will and
understanding in, 4(52; object of
man's highest moral aspiration and
effort, 49(5; source of all truth and
of all beings, 517.
Godwin, Francis, his " Man in the
Moon," 342, 551.
Gcebel, 602.
Gobi, Jacob, 287, 468; his "Lexicon
Arabico-Latinum," 287.
Gottling, 379.
Gombault, Antoine, 539.
Gonzales, Domingo, his " Voyage chi-
merique an monde de la lime," 342.
Gonzalez, Tirso, opposed probabilism,
418; his " Fundament um Theologian
moralis, tractatus de recto usu opi-
nioimm probabilium." 418.
Goodwin, W. W., his "Plutarch's
Morals," 476.
Goppert, his " Ueber einheitliche,
zusammengesetzte und Gesammt-
sachen nach rom. Recht," 75'. ».
Gorgias, 518.
Goropius, see Becan.
Gow, his " Short History of Greek
Mathematics," 527. [295.
Graff, E. Th., his "Gospel of Otfrid,"
Grammatical confusion in the text ex
plained, 768,
INDEX C
843
Grant, Alex., his "Ethics of Aris-
t,)lle," 321, 752, 753.
Greaves, John, his " Pyramidogra*
phia," 150.
Green, when the product of blue and
yellow, 320.
Gregory, IX., 444; XIII., reforms the
Calendar, 424.
Grein, C. \\'. M., his " Bibliothek der
Angel-Sachsischen Poesie," 295.
Gretser, Jacob, 618 : his response to
magistrates of Marckdorf, 618.
Gritnaldi, Charles Philip, 35)4.
Grimm, Jacob, his " Kleinere Schrif-
ten,'' 294; his " Deutsches Worter-
bnch," 294.
Groot, see Grotius.
Grotefend, C. L., his " Briefwechsel z.
Leil)ni/, Arnanld nnd Landgratin
Ernst, etc.," 463.
Grotius, Hugo, 03(5; founder of phi
losophy of law, 494 ; on man as a
social animal, 285; his " De Jure
Belli et Pads," 285; his " Epistohe
ad Gallos," 494.
Ground-truths, theoretical, how con
scious of, 735; practical, how con
scious of, 735.
Guericke, Otto von, 774; experiments
on vacuums, 127 ; his air-machine,
127; "Experiments nova ut vocant
Magdeburgica," 127.
Guerre, Martin, the story of his per
sonation, 310.
Guerrier, 629.
Guhrauer, Dr. G. E., his '• G. \V. Frei-
herr v. Leibnitz. Eine Biographie,"
xii, 213, 239, 334, 365, 394, 415, 434,
435, 436, 532, 573, 591, 712, 715, 765 :
edits " Leibnitz's De principio Indi-
vidui," 23!», 606, (523; edits "Leib
nitz's deutsche Schriften," 7, 379,
435, 602, 626, 736, 757, 764; his
"J. Jung nnd sein Zeitalter," 63(5;
edits Bodin's "Colloquium Hepta-
plomeres," (!48.
Guyon, Mine., 728.
Haaxman. biographer of Leeuwen-
hoek, 346.
Hadley, " Introduction to Roman
Law," 329.
Hagenbach, his " History of Doc
trines," 594, 729.
Hakluyt Society, the, 89.
Hamilton, Sir William, "Lectures on
Logic," 14, 311, 317, 408, 515, 568:
his "Reid," 50, 116, 136, 382, 463,
57(5, 764; Note A, 43, 576; on the
Infinite, 274; "Lectures on Meta
physics," 382, 734, 764.
Hamm, Ludwig, 346.
Hammer, Von, his " Gesch. d. Assassi-
nen," 197.
Hardy, Claude, his "Data Euclidis,"
465, 4(56.
Harlay, Archbishop of Paris, 348.
Harmony, Pre-established, 147, 319,
363, 420, 759.
Harris, \V. T., "Journal of Specula
tive Philosophy," 8.
Harrison- Verrall, his " Mythology and
Monuments of Ancient Athens," 390.
Hartenstein, his "Locke's Lehre von
der menschlichen Erkenntniss in
Vergleichung mit Leibniz's Kritik
derselben," 5,311 ; his " Hist. Philos.
Abhandlungen,"311,349; his edition
of " Kant," 332.
Harvey, William, 346.
Harzer, P., his " Leibniz's dynamische
Ausschauungen," etc., 775.
Hashishin, 197.
Hasse, his " Anselm von Canterbury,"
503.
Haureau, Barthe'lmy, his " Histoire de
la Philosophic Scholastique," ."49,
382, 503, 588 ; his " De la philosophie
scholastique," 7(57.
Haurisius, his " Scriptores Historiie
RomamB Latini veteres qui extant
omnes," 610.
Heath, James, his "Flagellum: or
Life and Death, Birth and Burial of
Oliver Cromwell," 543.
Hebrew in Gaunersprache, 292.
Hedge, F. H., in " Journal of Specula
tive Philosophy," 101, 154, 332.
Heereboord, Adrian, (533.
Hegel, his '• Gesch. d. Philos.," IDS,
15(5; on Boehme, 298; his " Vorles-
ungen iiber Beweise von Dasein
Gottes," 503 : emphasizes like Leib
nitz the concrete, 749 ; agrees with
LEIBNITZ'S CRITIQUE OF LOCKE
Leibnitz's view of absolute, 750; in
terprets Leibnitz's Principle of Indi-
viduation, 766.
Heidegger, J. H., edits works of Fab-
ricius, 102.
Helmont, Francois, Mercure van, 67,
101, 242; his " Opuscula philoso-
phica," 242; his relations with Leib
nitz, 242 ; Leibnitz writes his epitaph,
242 : physician of the Countess of
Connavvay, 732 ; — John Baptiste
van, (545.
Hendriks, Frederic, his " Contributions
to the History of Insurance," 54,0.
Henke, E. L. Th., his " Georg Calixtus
und seine Zeit," 582.
Heppe, his " Gesch. d. Pietismus," 602.
Heraclitns, 729.
Herbart, J. F., on "working over of
notions/' 463.
Herbell, J. F. M., translator of
Camper, 286.
Herbert of Cherbury, Lord Edward,
587; his "De Veritate," 95.
Herlinus, Christian, collaborator with
Dasypodius upon the "Analyses
Geometricae," 404 ; Hamilton's opin
ion of, 769; where examples of the
Analysis of, may be found, 769.
Hermathena, of Trinity College, Dub
lin, 108.
Herodotus, 389, 547.
Herostratus, the incendiary, 536.
Hertz, Wilhelm, 67.
Herzog, his " Realencyclopadie," 2%,
587, 592, 595.
Higginson translates Epictetus, 496.
Hippocrates, of Chios, 527 ; determines
area of lune, 527 ; — of Cos, 476, 527 :
"Father of Medicine," 476 ; based
practice of physic on observation,
476; enforced dietetics, 476; his
Aphorisms, 476 : his av^irvoia Travra,
conspirantia oinnia, 476.
Hispanus, Petrus, 322. [50, 68.
" Histoire des Ouvrages des Savants," I
Hobbes, Thomas, 93, 285, 450: his " De I
Corpore," 93 ; his " Six Lessons to the I
Professors of Mathematics," 93; his !
" Ue Give," 285; his "Leviathan," i
285, 450; his doctrine of Society, j
285: on truth, 450: a Nominalist,!
450; literature upon the teachings
of, 450: his "Leviathan" censured
by Parliament, 775.
Holden, Henry, his " Divinae Fidei
Analysis," 617 ; his controversy with
Arnauld, 617.
Holtzendorff and Virchow, their
" Samnilung wissenschaftlicher Vor-
triige," 425.
Hommeite, "man-ness,"' 369.
Honestuin and utile, 261.
Honorius, his "gallus pugnax," (510.
Hooghelande, Cornelius Van, 633.
Hooke, Robert, his " Micrographia,''
639.
Hooker, Richard, his " Laws of Eccle
siastical Polity," 566.
Hoole, Samuel, translator of Leeuwen-
hoek," 346.
Horace, "Epistles," 87, 328, 566;
"Satires," 335.
Hottentots, language of. 290.
Hughes, his " Loyola, and the Educa
tional System of the Jesuits," 619.
Hugony, 9.
Hultsch, F., his " Pappi Alexandrini
Collectiones qua supersunt," 521.
Humanities, 628.
Hume, accords with Leibnitz on basis
of morals, 735 : " Inquiry concerning
the Principles of Morals," 735; his
" Treatise of Human Nature," 736;
on Causes, 757.
Hunt, T. W., his "Csedmon's Exodus
and Daniel," 295.
Huygens, Christian, 150, 213. 539, 676,
723; his"Traite'delaLumiere," 150;
discovers double refraction, 150;
places the wave theory of light on a
sure foundation, 150; applies the
pendulum to the clock, 150 ; his " De
scription de 1'horloge a pendule."
150; experiments on the isochronous
pendulum, 150; his " De Ratiociniis
aleae ludo " 539; his " Cosmotheo-
ros," 550; his speculations concern
ing planets, 550 ; controversy with
Divini, 614 ; his " De motu corporum
ex percussione," 676; his "CEuvres
completes," 723.
" Hypothesis physica nova," its struct
ure, 677.
INDEX C
845
Ihn-al-Baitar, see Baitar.
Matins, Chronicle of, 99.
Idea, 330.
Ideas, their natural order, 289; pure
truths of reason, 325 : their content,
325 ; their realization, 325 ; in what
sense ''true" or "'false," 452; in
Divine Mind as ratio ties rerum sta
biles ft incotnmutabiles, 516; in
nate, their criterion, 733: simple,
mind active in reference to, 703.
Idee, 330.
Identitatis, principium, 569; indis-
cernibilium, principium, 332.
ISiov, 455.
Jdola Fori, omnium molestissima, 306.
lllyricus, Matthias Flacius, 294.
Image and Idea, 274.
Immams, 197.
Immediate Revelation of God to Soul,
Locke's statement concerning, 474.
liifactum, an action at law, 486.
In.cefsabilite, 245.
Indefinite-infinite, 162.
Independents, 600.
Indirect demonstration, 406, 491.
Indiscernibles, principle of, 332.
Individual, the, its existence alone
allowed hy Locke, 567.
Individualism, nominalist ic, 623.
Individuation, principle of, 239.
Inductive conclusions founded on
•' truths of fact," 493.
Infants, concerning their salvation,
594.
Infinite, the syncategorematic and cat-
egorematic, 161, 162; whence the
errors and difficulties in discussion
of. 274; cannot form an image of,
274: knowledge of the, denied, 274;
"trois sens du mot,'? 750.
Infinite series, 424.
Infinitesimal calculus, its application
in Newton's " Principia," 440; dis
covery of, 573.
.Infiintivum, iHilelhiittim. 162.
" Inner Light " defined, 599, 773.
Inspiration, Divine, gives " lumen
Gratiae," 576; regarded as associ
ated with mental derangement, 598.
"Instinct," how used by Leibnitz,
Insurance, John de Witt, its first sci
entific propounder, 540.
Intelligence. The Supreme, His rela
tion to ideas, 763.
Intuition, immediate, of Plato, 575.
''Inward Light" of William Penn,
602.
Ionic School of Philosophy, 519.
Jackson, H., on the dai^viov of Soc
rates, 598.
Jacoby, D., his " De Leibnitii studiis
Aristotelis," 753.
Jacques, Amedee, his " CEuvres de
Leibniz," xii, 42, 46, 47, 49, 50, 53,
56, 58, 62, 63, 73, 80, 87, 89, 90, 91,
97, 101, 118, 119, 120, 121, 123, 125,
147, 150, 154, 184, 185, 203, 204, 205,
210, 211, 213, 218, 219, 240, 245, 246,
249, 251, 254, 257, 259, 263, 267, 270,
273, 274, 275, 282, 283, 284, 290, 298,
300, 301, 310, 314, 316, 321, 323, 326,
332, 333, 334, 346, 349, 352, 363, 381,
382, 383, 386, 405, 412, 414, 460, 466,
476, 496, 497, 504, 506, 508, 511, 522,
537, 548, 550, 551, 553, 580, 588, 705,
727, 750, 751, 754, 766, 768.
" Jalk ut Chad asch," 242.
James, W., his " Psychology," 760.
Jancourt, his " Historia vitas Leib
nitii," 573.
Janet, " CEuvres philosophiques de
Leibniz," 73, 451, 463, 705, 727, 734,
735, 738, 739, 740, 741, 749, 750, 751,
754, 756, 760, 761, 762, 763, 764. 765,
766, 768, 769; his " La Morale," 418.
j Janney, his "Life of William Penn,"
602.
j Jan sen, H. C., translator of Camper,
286.
Je ne say quoi, applied to ultimate
essence of things, 128.
Jebal, Sheik-al, 197.
Jenichen, J. A., 626.
Jerome, his " Ad Ctesiphontem," 345.
Jerome de la Lande, 551.
Jesuits, 418.
Jevons, W. S., his " Principles of Sci
ence," 214 ; " Lessons in Logic," 322 ;
his " Substitution of Similars," 569.
Jocher, his " Allgemeines Gelehrten-
Lexicou," 403, 585, 586.
846
LEIBNITZ'S CRITIQUE OF LOCKE
"Journal," "des Savants," 15, 101,
420, 507; "of Speculative Philoso
phy," 8, 101, 332 ; " for Math.,"
Crelle, 571 ; " of Philology," 598.
Jowett, translator of " Politics of Aris
totle," 285, 482 ; translator of " Dia
logues of Plato," 291, 292, 298, 390.
Julius, Duke, his decision in the case
of Martin of Helmstadt, 582.
Jung, Joachim, 636.
Jurists, the Roman, Leibnitz's opinion
of, 415.
Jus accrescendi, 434.
Jus non ex regula sumatur, sed ex
jure, 487.
Justin Martyr, his " Apologies," 591 ;
his " Spermatic Logos," 591.
Justinian, his " Institutes," 434, 487,
492, 591 ; his " Codex," 497.
" Kabbala " on pre-existence of souls,
250; "Denudata," 732.
Kadlubek, Vincent, his " Historia
Polonica," 546.
Ka^fSXou irp&Tov, 488.
Kalbkopf, see Moscherosch.
Kant, his " Kritik d. prakt. Ver-
nunft," 184; his "Die Religion in-
nerhalb der grenzen der blossen
Vernunft," 248; his " Kritik d. rein.
Vernunft," 128, 332, 503, 733; " Di-
lucidatio nova," 332 ; his a priori
(necessary and universal) and a
posteriori (contingent and actual)
thought, 725 ; his Kategories or
original notions of the understand
ing, 726, 737, 741 ; on truths of
reason, 733 ; refers to Copernicus,
733; his reason practical, 754; his
definition of "virtue," 754; his
ground of faith in immortality, 755.
Keckermann, Earth., 311 ; his proof of
Trinity, 589; his " Systemass. Theo-
logue," 589; his "Opera omnia,"
589.
Kelle, J., his " Gospel of Otfrid," 295.
Kepler, John, 123; his " Somnium seu
de Astronomia lunari," 551. "*
Kerkkrinck, Theodore, his " Anthro-
pogenise Ichnographia," 345.
Kessler, Andreas, his " Physicre Pho-
tiniante Examen," 580 ; his " Meta
physics Photiniarise Examen, "586;
his "Logicae Photinianae Examen,"
586.
Kestuer, his " Mediciiiisches Gelehrten-
Lexicon," 521.
King, his " Life and Correspondence
of Locke," 728.
Kings, I., 8:27, 158.
Klrchmann, J. H. von, his " Philos.
Biblioth.," 125, 227, 239, 286, 349, 504,
540, 552, 555, 613, 732, 739, 748, 754 ;
his "Die klein. philos. wichtig.
Schrift. v. G. W. Leibniz," 218, 227,
239, 722, 723; " Erlauterungen zu
J. Locke's Versuch. ii. d. menschl.
Verstand," 555 ; his " Erlauterungen
zur The'odice'e," 751, 758.
Kirchuer, his" Leibniz's Psychologic,"
752.
Kleutgen, his " Philosophie d. Vor-
zeit," 382.
Klopp, O., his "Die Werke v. Leib
niz," 239.
Knowledge, mediate and immediate,
109 ; its relation to Kant's division
of, 109 ; of senses, how classified, 317.
Konig's " Appel," 713.
Kortholt, Christian, his " Leibnitii
Epist. ad diversos," 415, 486, 606.
631, 632, 748 ; — Sebastian, Leibnitz's
letter to, 436.
Koschny, Erick, 218.
Kotter, C., 604.
Krafft, his " Kirchengesch. d. deutsch.
Volker," 296.
Krauth-Fleming, their "Vocabulary
of Philosophical Sciences," 125, 136,
330, 363.
Kuhlmann, Quirin, his hallucination
and fate, 601.
Kummer, his " Festrede am Leibuiz-
tage," 425.
Labadie, Jean de, 602.
Labadists, 602.
Labbe, Philippe, 293; his " Concordia
chronologica, technica et hislorica,"
293; his " Erudit<e pronuntiationis
catholici indices," 293.
Lacoste, Bertrand de, his " Scheda de
inventa quadratura circuli," (i04.
Lactantius. 327.
INDEX C
847
Laertius, Diogenes, his " De vitis, dqg-
matibus, et apophthegmatis claro-
rum philosophorum libri decem,"
385, 518, 519.
Lagrange, Jos. Louis, 393.
Lallemant, Ave, his "Das deutsche
Gaunertlmm," 292.
Lambert of Auxerre, his "Summa
Logic*," 322.
La Mothe le Vayer, Francois de, 593;
his " De la vertu des pa'iens," 593.
Lang, Andrew, his " Myth, Ritual and i
Religion," 85.
Lange, his " Gesch d. Materialismus," |
3ii3, 421, 592, 727, 730, 774 ; his article I
•' Vives," in " Encykl.d. ges. Erzieh. |
-u. Unterrichtswesen," 592.
Langley, Alfred G., his article, "Reve
lation. Inspiration and Authority,"
in " Andover Review," 32, 195.
Language, an aid to society, 28(3; of
apes, 280; Leibnitz's mistake as to
its origin, 288; involves advance to
abstract ideas, 290; early discus-!
sions upon, 291; Leibnitz upon for- I
ination of, 292 ; modern discussions I
upon, 292; philosophical, 292, 375.
Languages, Leibnitz's presentiment of i
their connection, 297; the compara
tive study of, recommended, 298.
Laplace, his " Theorie analytique des j
probabilites," 213.
Larousse, P., his "Dictionnaire uni- :
versel du XIXe siecle," 310, 443, 494,
527, 539.
Lasiks, 197.
Lasswitz, his "Gesch. d. Atomistik,"
(5:52,633,635, 636, 639, 645, 64(5, 648,
676, 684, 723, 727, 730, 732, 735, 740, !
751, 752, 771,774.
Lateran Council, the fifth, 581.
"Latin," 0opd, 321.
Laurie, S. 8., his "Comenius," 466.
Leclerc, his " Bibliotheque universelle
et historique," 26.
Leemvenhoek, Anton van, discovers
spermatozoa and capillary circula
tion, 346; opposes "spontaneous
generation," 346.
Leibnitz, Gottfried "Wilhelm; his
" Meditationes de Cognitione, Veri-
tate et Ideis," 3, 14, 17, 227, 2(56,
317, 363, 404, 502 ; his correspondence
with Bierling, 3, 101, 131, 436, 542,
721, 748; his correspondence with
Buruet, 6, 7, 382, 458, 478, 599, 728 ;
anonymous letters of, 8, 712; cor
respondence with Coste, 9; cor
respondence with Remond, 9, 101,
131, 731; correspondence with Lady
IVlasham, 9, 65; titles given by him
self to his review of Locke's Essay,
9, 10, 65 ; his use of parentheses in
" Nouveaux Essais," xiv, 10; his
" Eclaircissement des difficultes que
M. Bayle a trouvees dans le systeme
nouveau de 1' union de 1'ame et du
corps," 50; his remarks on " Rora-
rius," 66, 507; his " Considerations
sur la Principe de Vie et sur les
Natures plastiques," 67, 68, 363, 731 ;
his relation to Spinoza, 69 ; his " Sys
teme nouveau de la nature," 101,
147, 154, 346, 349, 363, 733 ; his " Res
ponse sur reflexions contenues dans
la seconde edition de Dictionnaire
critique de M. Bayle," 101, 333, 508,
539; his correspondence with R.
Ch. Wagner, 101, 131, 379, 550. 559;
his correspondence with Fardella,
101 ; his correspondence with Dan-
gicourt, 101 ; his correspondence
with Arnauld, 101, 334, 426, 463, 553,
739; his " De ipsa natura," 101, 154,
218, 332, 349, 383, 705; correspon
dence with Des Bosses, 101, 128, 1:51,
155, 229, 341, 740 ; correspondence
with De Voider, 101 ; correspondence
with Bourguet, 101, 213, 43(5, 561;
correspondence witli von Hessen-
Rheinfels, 101 ; his " Un petit dis-
coursde Metaphysique." 101,261, 319,
330, 349, 49(5, 553, 554 ; his " Specimen
dynamicum pro admirandis naturae
legibus," 101, 174, 383, 670. 733, 751 ;
his "Principe de la Nature," 101;
his " La Monadologie," 101. 225,332,
502, 511, 733; his correspondence
with Clarke, 128, 332, 381, 383, 553,
749, 750; correspondence with Tolo-
mei, 131 ; his " De anima brutorum,"
131; his " Principes de la nature et
dela grace fondes en raison," 136, 346,
363, 502; his "Codex juris gentium
848
LEIBNITZ'S CRITIQUE OF LOCKE
diplomatics, " 167, 495, 496, 750; his !
" De notionibus juris et justitiae,"
167; his " De primae philosophic!
emendatione," 154, 174: his corre- |
spondence with Fabri, 174, 586, 676, I
69*), 751 ; his " Essaisde Theodicee," |
180, 227, 239, 310, 333, 334, 349, 382, j
383, 415, 450, 496, 508, 511, 551, 553,
576, 581, 582, 585, 586, 587, 589, 590, '
592, 594, 595, 602, 606, 635, 752 ; I
on logic of probabilities, 213; ac- j
quainted with Pascal's investigations
on probabilities, 213; on creation, j
225 ; his correspondence with Bayle, !
225,261,334; his " Disputatio Meta- |
physica de principio individui,"239,
(306,623; correspondence with Sophie j
Charlotte, 239, 748: his "Miscel
lanea," 242, 435, 443, 539, 590; his
"De stilo philos. Nizolii,'' 272, 450,
588, 623 ; his correspondence with
Geheimrath von Ilgen,293: his corre
spondence with Fr. S. Loeffler, 298;
was an idealistic realist, 319: his
"Animadversiones in partein gener-
alem principiorum Cartesianorum,"
334, 363, 504 : his views of substan
tial forms, 349; "Leibniz gegen
Descartes nnd den Cartesianismus," j
363; on Pythagoras. 379 : his opinion j
of formal Logic, 379, r>.">9: his corre- i
spondence with G. Wagner, 379, 559; j
correspondence with Placcins, 382, j
43."), 520 ; correspondence with editor
of "Journal des Savans," 383: cor
respondence with Alberti, 383 ; cor
respondence with Thomasius, 383, j
606, 631, 769: correspondence with!
Hobbes, 3H7, 450: correspondence
with Kestner, 415, 417, 436, 486;
his "Epist. ad di versos," ed. Kor-
tholt, 417, 486, 748; correspondence
with S. Kortholt, 436, 438, (549, 748;
correspondence with Foncher, 420,
677 ; correspondence with Male-
branche, 421 : his infinite series, 424 :
his infinitesimal calculus, 424, 573;
correspondence with Con ring, 425,
504, 520, 521, 769, 771 : his " De vera
proportions circuli ad quad rat um
circnmscriptum in nnmeris ration-
alibns," 425; his "Thesis de con-
ditionibus," 434; his " Specimina
Juris," 434; his " De Arte Com-
binatoria," 434, 561; on Weigel,
485; his criticism of Pufendorf, 436;
his " Monita quaedam ad S. Puffen-
dorfii principia," 436; his " Pre-
ceptes pour avancer les sciences."
437: a philosophical fragment, 437;
his " Reflexions sur 1'ouvrage que
M. Hobbes a publie de la liberte,
de la necessite et du hazard," 450,
451; on Revelation, 474: his " Uui-
cum opticae catoptricae et dioptricse
principium," 484; his " Xova me-
thodus discendae doeendaeque juris-
prudentiae," 486 ; his " Nouvelles
lettres et opuscules ine'dits,'' by
Foucher de Careil, 496 ; on rela
tion of Natural Theology to Meta
physics, 496 : his letter to Electress
Sophie, 496 : source of ethical truth
according to, 496 ; his " Definitiones
ethicai," 496; on ontological argu
ment for existence of God, 5O2 :
his doctrine of Monads requires ex
istence of God, 502; his " De la de
monstration Cartesienne," 502, 504 :
his " Confessio Naturae contra Athe-
istas," 502 ; his correspondence with
Jacquelot, 504 ; his correspondence
with Eckhard, 504; his "Probatio
existientiffi Dei ex ejus essentia,'1
504 ; correspondence with Basnage de
Beauval, 507, 727; his "Observatio
ad rescensionem libri de fidei et rati-
onis consensu a Domino Jacqueloto
editi," 511; bis " De modo distin-
guendi phenomena realia ab imagi-
nariis," 513 ; regarded idea of God as
constitutive, 517 : regarded idea of
God as principle of all thought, 517;
regarded actuality of God as consti
tutive principle of all things, 517;
his correspondence Avith Bossuet,
544; bis " Introductio in collec-
tionem Scriptorum Historiae Bruns-
vi*»ensi inservientium," 546 ; his
correspondence with Tentzel, 553:
his " Response aux objections centre
le systeme de 1'harmonie preetablie
qui se trouvent dans le livre de la
connoissance de soy-memes," 553;
INDEX C
849
his "Systema Theologicum," 554;
his correspondence with Hartsocker,
554,740; his "Annotatiunculae subi-
taneae ad Tolandi librum," 554, 579;
his views of miracles, 554 ; his " Diffi-
cultates qusedam logicae," 561 ; his
controversy with Newton, 573; his
" Histoi'ia et origo calculi differen-
tialis," 573 : his correspondence with
Countess Kielmanusegge, 573; his
"Hypothesis physica nova," 586;
his " Theoria motus abstract!," 586,
634: his views of the Trinity, 590;
his "Defensio Trinitatis," 590; his I
" Dure Epistolae ad Loeflerum," 590;
his "Remarques sur le livre d'un
Autitrinitaire Anglois," 590; letter!
to M. B., 590; his correspondence'
with Pellisson, 591, 592 : his corre- 1
spondence with Magliabechius, 592 ; j
his correspondence with Fabricius, '
592 ; his " Sur 1'esprit sectaire," 600; |
his correspondence with Spizel, 602 ;
his correspondence with Wolf, 606;
on Nominalism, 623 ; his " Idea Leib-
iiitiana Bibliothecse Publican," 626;
his " Representation au Due de
Wolfenbuttel pour Feucourager a
Tentretien de sa Bibliotheque,'' 626;
his relations with Peter the Great,
629, 740; his "Theoria motus con-
creti," 634, 733 ; correspondence
with Spener, 649 ; correspondence
with Huygens, 676, 767 ; corre
spondence with Wallis, 677 ; his
comparison of himself to Plato, and
of Locke to Aristotle investigated,
723, 724 ; his "Remarques sur le
Sentiment de M. de Worcester et
de M. Locke," 728; is "inclined
towards ethics," 731 ; eclectic in
thought. 731 ; his "Animadversiones j
circa Assertiones aliquas Theorise
Medicse verse Clar. Stahlii," 733:
his " Vermischte Bemerkungen und
Urtheile," 736 ; correspondence with
Leuwenhoek, 740; his "Observa
tions iiber die Magnet-Nadel," 740;
correspondence with Guericke, 741 ;
his " De Libertate," 752: on Made
moiselle de Scude'ry, 757 ; his " Ob-
ser.vationes de Priucipio Juris,"
3i
761; his " Bedenken welchergestalt
den Mangeln des Justiz-Weseus in
theoria abzuhelfen," 764 ; letter
from Burckhardt to, 766; corre
spondence with Gackenholtzius, 76(i;
his "Critical Essay on the Story of
Balaam," 767.
Lemnius, Leviuus,448; his " De mira-
culis occultis naturae," 449.
Lessing, his "Theolog. Streitschrif-
ten," 194; his statement regarding
search after truth vindicated, 194,
195; his " Erziehung des Menschen-
geschlechtes," 248 ; his " Dass meni
als fiinf Sinne fiir den Menscheu
sein konnen," 584.
Lessius, quoted by Pascal, 749; " De
justitia et jure, "749; his theological
works, especially on Freedom of
Will, 749.
Library, Leibnitz on its classification
and catalogue, 626.
Libri, his " Histoire des Sciences ma-
thematiques en Italic," 572.
Licet i, Fortunio, on monsters, 351 ;
Guiseppe, on monsters, 351.
Light, Aristotle's definition of, 321;
the inner, 591 , 599.
Lignum nephriticum, 769.
Limborch, 733.
Lincoln, J. L., his "Marcus Aurelius
Antoninus," 771.
Lindemann, demonstrates non-alge
braic character of ?r, 425.
Linden, J. A. van der, his " De scriptis
medicis," 521.
Linea prsediccunentalis, 322.
Lipenius, Martin, his various " Biblio-
thecse reales," 62(5 : his use of realis.
626.
Littre, his " Diction naire de la langue
francaise," 191, 757; his " CEuvres
completes d'Hippocrate," 476.
Lobeira, Vasco de, his " Amadis de
Gaul," 399.
Locke, John, his "Essay" translated
and summarized in " Bibliotheque
Universelle," 4; editions of his
" Essay," 4 ; his " Essay " translated
by Coste, 4 ; his " Thoughts on Edu
cation, 5 ; " Some Familiar Letters ''
of, 5, 6; correspondence with Moly-
850
LEIBNITZ'S CRITIQUE OF LOCKE
neux, 6, 747 ; his philosophy con
trasted with that of Leibnitz, 310,
723; his view of substantial forms,
349 ; on truth, 452 ; on religion,
474; his view of reason, 555; his
sensistic realism, 567 ; his " Exami
nation of Malebranche," 578 ; on rea
son and faith, 579; his controversy
with Stillingfleet, 728; his idea of
creation of matter, 772.
Logic, formal, the views of Locke and
Leibnitz regarding, 555, 559, 561 ; its
function, 555.
Ao7os, its part in formation of society,
286: defined, 555.
Long, George, his translations of the
" Thoughts of Aurelius Antoninus,"
and of the "Discourses, Encheiri-
dion and Fragments of Epictetus,"
4:16.
L-mbere, La, Simon, 60.
Lucan., " Pharsalia," 144.
Lucian, his "Lucius or Ass," 243; his
"True Histories," 399.
Ludolph, see Ceulen.
Ludolphe, John Job, his " Tetragono-
metria Tabularia," 75.
Ludolphische Zahl, 734.
Lully, Raymond, his " Tabula Logica,"
322; inventor of the "Great Art,"
590 ; his "Articuli Fidei Sacro-
sanctae," 590.
Lumen, naturals, 576; gratiss, 576.
Lunafixa, 324.
Lime, first curvilinear space whose
area was determined, 527.
Luz, nK, the incorruptible bone of the
Rabbis, 242.
" Lyra Germanica." 586.
Lycosthenes (Wolffhart), 548.
Maass, Johann G. E., 764.
.Machine (i.e. body), a term among
Cartesians, 348.
Madvig, his edition of Cicero's " De
Finibus," 272.
Magnet, Leibnitz on, 740.
Magnitude, Imperfect, what? 761.
Magot, 342.
Maher, his " Psychology," 382.
Mahaffy, J. P. his "Descartes,"
727.
Maimbourg, his " Histoire du Luthera-
nisme," 544.
Majority of professors, argument
from, 531.
Malebranche, Nicolas, his " De la Re
cherche de la Ve'rite," 64, 176, 421;
on " seeing things in God," 153; his
" Traite de la communication du
mouvement," 176 ; opposed by
Regis, 348; his change of view, 752.
Malpighi, 346.
Man, a selfish or a social animal ? 285.
Mancini, his monograph on Valla, 415.
Man-ness, as a translation of liom-
meity, 369.
Mansel on the Infinite, 274; on limita
tion of axioms, 770.
Marci von Kronland, Johannes Mar
cus, 676.
Marinus, Neo-Platonist, and commen
tator on Euclid, 465.
Mariotte, Edme, 121; discovers blind
spot in retina, 121.
Mark 7: 11-13, 327.
Markham, Clements R., translator of
Garcilasso de la Vega, 89.
Martineau, James, his "Types of
Ethical Theory," 153, 421 : his
"Study of Spinoza," 633; a mis
take of his, 633.
Masham, Lady, 65, 730.
Mass, what? 722.
Massa perditionis, infants naturally
a part of, according to Augustine,
594.
Massmann, H. F., his "Die kleinen
Sprachdenkmale des VIII bis XII
Jahrhundert," 294; his "Ulphilas,'
296.
Materia prirna, 110.
Mathematics as science of magnitude
applicable only to sensible things,
756.
Matthew 5: 5, 6, 327.
Matter, primary and secondary, 131 ;
can it think ? 427 ; what ? 722 ; sub
tile to infinity, 722.
Maupertuis. his charge against Ki'mig,
713.
Maurier, Louis Aubery du, his Dutch
" Memoires," 542.
Maurolico, Francesco, his "Treatise
INDEX C
851
on Conies," 442; his " Problemata
ad perspectivam et iridem perti-
nentia," 442; his " Theodosii sphae-
ricorum," 442; his "Photismi (or
Theoremata) de lumine et umbra,"
etc., 442.
Maywald, M., his "Die Lehre v. d.
zweifaehen Wahrheit," 581.
Mechanism, its source, 721.
Medius terminus, 481.
Megarian School of Philosophy, 93.
Meier, Gerhard, 304, 765.
Melancthon, 592.
Membranes, what Leibnitz meant by?
740.
" Memoires de Trevoux," 444, 502.
Menage, Gilles, his " Dictionnaire
etymologique de la langue fran-
caise," 344.
" Menagiana," 350.
"Mentor, the," a magazine published
by the blind, 747.
" Mercure galant," 438.
Mere, Chevalier de, 213; his " Agre-
mens," 539.
Merkelius, editor of Ovid, 211.
Mersenne, 410; his " Synopsis," 465.
Merz, J. T., his " Leibniz," 307, 629.
Merzeriac, Bachet de, 571.
Metempsychosis, Aristotle opposes,
760.
Meyer, H. A. W., " Kommentar," 327.
Michaud, his "Biographic Univer-
selle," 401, 418, 520, 546, 551; his
" Histoire des Croisades ," 197.
Microcosm, 109.
Middle term, 770.
Migne, his " Theologiae Cursus com-
pletus," 749; his " Patrologife Cur
sus corapletus," 345, 443, 502, 516,
546, 618, 737.
Milky Way, the successful conjecture
of Democritus concerning, 277, 763.
Mill, J. S., his " Logic," 213, 769.
"Mind," 69.
Mind, what we know in. 721.
Minute perceptions, the value of
Leibnitz's teachings on, 727.
Miracles, Leibnitz's attitude towards,
606, 607.
Mnemonics, their alleged invention,
214.
"Modes," Descartes on, 748; mixed,
their formation according to Locke,
757, 768.
" Mola," 344.
Moliere, his " Don Juan ou le Festin
de Pierre," 53(5.
Molyneux, William, founded Dublin
Philosophical Society, 138; his "Di-
optrica Nova," 138, 484; his corre
spondence and relations with Locke,
747.
Mommsen, Theodore, his edition of
the "Digests." See Corpus Juris
Civilis.
Monad, the term whence borrowed,
101 ; where first mentioned, 101 ; the
writings of Leibnitz in which men
tioned, 101; the primitive, 722 ; the
derivative, 722; how divided, 722;
inextinguishable, 722; the created,
endowed with an organic body, 722 ;
contains the entelechy, 722 ; like
mirror, 738.
Monadology not pantheistic, 732.
Monatliche Auszug, 26.
"Monist, the," 425.
Monists, Leibnitz, Spinoza, and Locke
were in different ways, 757.
Montague, Vieux de la, 197.
Montferrat, Conrad of, 197.
Montalvo, Garcia Ordonez de, 309.
Montucla, his "Histoire des Mathe-
matiques," 572, 573.
" Monumenta Germanise Paeda.go-
gica," 619.
Moon daemons, 551.
Moral Law, Leibnitz's view of, 262 ;
E. G. Robinson's view, 262.
Moral Philosophy, Pythagorean prin
ciple applied to, 435.
Morality, according to Hume, "de
pends on some internal sense or feel
ing," 735,736.
More, Henry, his theory of pre-exist-
ence of souls, 250 ; on aerial vehicles,
380; his principium hylarchicumov
Spiritus nfitiirse, 382; his friendship
with the Viscountess Conway, 732.
Moreri, his mistake, 539.
Morhof, his " Polyhistoria," 636, 650.
Morley, Henry, his "English Writers,"
295.
LEIBNITZ'S CRITIQUE OF LOCKE
Moschevosch, John Mich., his " Ge-
sichte Philanders von Sittenwald,"
293.
Motion, Aristotle on, 320; the source
of laws of, 721.
MoutoD, Gabriel, invents " Method of
Differences," 150; his "Observa-
tiones diametroruni solis et lunse
apparentium," 150.
Muler, Nicolas, his " Astronomia In-
staurata," 419.
Mulford, his "Republic of God," 503.
Mullach, his "Fragmt. Philos. Graec.,"
379, 519.
Miillenhoff uud Scherer, their " Deuk-
maler deutsche Poesie und Prosa aus
Vlll-XIIJahrh.," 294.
Mtiller, Julius, " Die Christ. Lehre von
der Siinde," 248 ; — Max, " Lectures
on the Science of Language," 764, 765.
Mundy, the blind sculptor, 747.
Mus«?us, Johannes, his " De Luminis
Naturae," 587 ; his " De usu principi-
orum rationis et philosophise in con-
troversiis theologicis," 587, 590.
Musseus, his " poem of love and
death," 211.
Mystics, mediaeval, 576, 728.
"Nation, the," 764.
" Naturals, " 341.
Nature, copies after, what? 353; an
aggregate of monads, 722 ; conserves
"the same force," 731; conserves
" the same total direction," 731.
Naude', Gabriel, his " Apologie des
Grands Homines Soup<,'onnes de
Magie," 278; founder of " Biblio-
theque Magazine," 580; Naudeana,
580.
Neander, his " History of the Christian
Religion and Church," 345, 443, 444,
590.
Neff , L., his " G. AV. Leibniz als Sprach-
forscher und Etymologe," 304, 376.
Nerves, " end organs " of, 739 ; specific
energy of, 739.
Newton, Sir Isaac, 233; his " Prin-
cipia," 440; first to apply infinitesi
mal calculus to physics, 440; his
'• Optics," 443 ; almost a Berkeley an,
773.
Niam-niam, the, 341.
Niceron, J. P., his " Me'moires d'hom-
mes," 587.
Nichol, John, his " Bacon," 306.
Nicole, Pierre, 418, 530; his " L'Art
de Penser," 531; his "Essais de
Morale," 531 ; his " Unite' de 1'e'glise
on refutation du nouveau Systeme
de Jurieu," 531.
Nihus, Bartholomew, his controversy
with Vedel, 587.
Nithard, his " Historia de dissidio fili-
orum Ludovici Pii," 24)4.
Nolen, his "Leibniz, La Monadologie,"
511 ; his " Quid Leibnizius Aristoteli
debuerit," 753.
Nominalism, 623.
Nominalists, 382.
Nonrisson, M., his " La Philosophic de
Leibniz," 752, 775.
Nous of Plato, 555, 723; of Aristotle,
555.
" Nouvelles de la Republique des
Lettres," 50, 334.
Obreption, 276; Leibnitz's definition
of, 762.
Occam, AA^illiam of, 450; develops
Nominalism in form of Terminism,
382, 588.
Oi/ce/wo-ts, 286.
Oldenburgerus, Philippus Andrea, (>50.
Oleum Martis et Veneris, 324.
Olle-Laprune, his "La Philos. do
Malebranche," 421.
Onesirnus, " adhuc in vino pruden-
tior," 762.
"Ontosophia," 303.
Order, the historical, 470; the natural
or logical, 470.
Ordo prsedicamentalix, 322.
Ordonez, Garcia, 399.
Origen, a believer in pre-existence, 248 ;
on " Visio Beatifica," 575.
" Orlando, Furioso," 399; " Innamo-
rato," 398.
Orphica, 153.
Ostensives, 491.
Otfrid, his "Life of Christ," 294; in
troduces rhyme, 295.
| Ovaia, in Aristotle, 349.
I Ovid, his "Tristia," 56, 729; his
INDEX C
"Metamorphoses," 68, 190, 733; his
"Heroides," 211 ; his " Fasti, "598.
Pajon, Claude, his view of conversion,
5H5.
Pali'yu, Jean, 351.
Paused us, 261.
Pandects, see Corpus Juris Civilis.
Pappus of Alexandria, 521 ; his " Lem
mata," 465; his " Synagoge," 521;
his explanation of analysis and syn
thesis, 521.
Paracelsus, Theophrastus, (545 : his
" Philosophise Sagax," 730; " De
Xymphis, Sylphis, Pygmseis et Sala-
rnandris," 730.
Pardies, Ignace Gaston, 676.
llappr)ffia (parrhesia), 223.
Pascal, founder of Calculus of Proba
bilities, 213; on equitable division
of stakes in games of chance, 213;
his " Lettres Provinciales," 418, 749.
Pasch. G., on " De novis inventis,"
521.
Passion in spirit, what? 750; its rela
tion to pain, 756: in bodies, 756.
Paul. Hermann, 292; his " Principien
der Sprachgeschichte," 292 ; his
" Grundriss d. germ. Philologie,"
295, 29(5.
Paulas, on source of rules, 487 ; his
" Sententiarum," 534.
Pausanias, quoted, 390.
" Peccatum originale," 594.
" Pellucid, the," in Aristotle, 321.
Penjoii, his " De Infinite apud Leib-
nitium." 750.
Penn. William, (i02.
Penzler, M., his " Die Monadenlehre
und ih re Beziehung z. griech. Phi-
losophie," 752, 753.
Perception and apperception, 136.
Perfectibility, 755; relation of lumi
nous pleasures to, 755.
Peripatetics, 362, 455.
" Perles de De Sluse," defined, 768.
Persius, his " Satires," 264, 272.
Personality, double and alternate, 7(iO.
Pertz, his " Monumenta Germanise
Historica," 2i)4.
Peters, F. H.,translatorof" Aristotle,"
285.
Petitio princlpii, 84.
Petronius, " Satyricon," 204, 482.
Petrus, Hispanus, 322.
Prleiderer, O., on Boehme, 298; his
"Religionsphilosophie," 249, 298,
503, 553, 584, 598.
" Phantasies, "how to render the term,
445.
Phantasm, 445, 459; Hobbes' use of,
769.
Phenomena, connection of, 422 ; pro
duces certainty in sense-knowledge,
422; verified by truths of reason,
423.
Philo, 598, 732 ; on pre-existence, 248 ;
on " Visio Beatifica," 575.
" Philosophia Altdorfiana," 635.
Photinians, 586.
" Physical," its occasional meaning in
Leibnitz, 261.
Piccart, Michael, 63(5.
Pichler, his "Die Theologie des Leib
niz," 511, 532, 554, 579.
llivat. of Cebes, its genuineness, 436.
! Piper, P., an editor of " Otfrid," 295.
Pisani, Ottavio, 764.
Planck, M., his "Das Princip der
Erhaltung der Energie," 775.
Plato, 66; his " Meno," 78: his
" Phaedo," 170, 240, 436 ; his " Pha>-
drus," 192, 250, 598 ; on pre-existcnce,
248,768; his method of teaching, 272;
his "Cratylus," 291,292,299; €l5os
in, 349; his "Symposium," 390;
Leibnitz's opinion of, 416 ; on im
mediate intuition, 575; his "Ion,"
598; his "Timaeus," 598; Leibnitz
compares himself to, 723; his doc
trine of reminiscence, 726 ; his
world-soul, 732, 768.
Plautus, "MeiuBchmi," 226.
Pleasure, according to Aristippus, 518.
"Pliable," the epithet explained, 723.
Pliny, the Elder, " Historia Natur-
alis," 316.
Plotinus, 598: on ecstatic intuition,
575; his world-soul, 732.
Plutarch, 476, 598; his " De Fafo,"
476; his "Moralia," 476, 551; "De
Facie in orbe luna?," 551 ; on moon-
dremons, 551 ; his " Placita Philo-
sophorum," 724.
854
LEIBNITZ'S CRITIQUE OF LOCKE
llvev/ji.a, Cremer upon, 289.
"Pneumatics," as a term in mental
philosophy, 362.
Pneumatology, 50, 363.
Pneumatosophy, 363.
Poe, Edgar A., refers to Gonsales, 342.
Poiret, Pierre, biographer of Antoi
nette Bourignon, 599; his " CEco-
uomie de la Nature," 599.
Poisson, his " Recherches sur la Proh-
abilite," etc., 213.
Polenio, statement of Stobseus con
cerning, 518; his philosophy, 518.
Pollock, F., his " Spinoza, his Life and
Philosophy," 345, 733. [315.
Polyhedra, the only possible regular,
Pomponazzi, Pietro, 581; his " Trac-
tatns de Immortalitate Animi," 581.
Pomponius Sextus, 241, 48(5.
Poniatowa, Christine, a visionary, (!04 ;
her death from chagrin, 604; her
visions rendered into Latin by
Comenius, 604.
Porphyry, his " Tabula Logica," 322;
his Eiffaywy/i, 322.
Port Royalists, 530.
Portugal, Sea of, 134.
Possible, everything which is, an ob
ject of intelligence human or divine,
763.
Poste, his " Gaius, Elements of Roman
Law," 329.
Potestas Diaboli, infants under, ac
cording to Augustine, 594.
Pouchet, F. A., his " Histoire des Sci
ences naturelles en moyen age," 371.
Power distinguished by Leibnitz from
force, 751.
PpSBtUcftbilia, Prsedlcamenta, 322.
Prgescriptiones, 531 .
Prantl, his " Gesch. d. Logik," 116, 322,
349, 382, 408, 415, 456, 488, 515, 565,
588, 590, 765, 770.
Pre-existence of souls, 248 ; no expla
nation of the origin of sin, 248, 249.
Preller, his " Griech. Mythologie," 390.
Premise, when the philosophical is
general and the theological is par
ticular, what is to be done? 761.
" Prince, A great," Leibnitz's expec
tation from one in the future, 629.
Priscillianists, 345.
Probabiliorism, 418.
Probabilism, 418.
Probabilities, Calculus of, 213.
Probability, Aristotle's definition of,
214 ; logic of, 417.
Proclus, Diadochus, 93, 108, 465; the
" schoolman of Neo-Platonism,"
108; his "Treatise on the Sphere,"
108; his "Institutes of Theology,"
108; his "In primum Euclidis Ele-
mentorum libruin commentarii,"
108, 463; Leibnitz's opinion of, 416.
Procopius, alleged author of " Anec-
dota," 542.
Proculus, 762.
Prolepses, Stoic doctrine of, 724.
<; Promoter," defined, 757.
Proof, indirect, what? 406.
Propositions, " weaker," 515.
Propria, 455.
Proprium, 455.
Prosthapha>resis. 540.
Prosy llogism, 404.
Proverbs, Book of, 437.
Pucci, Francesco, 593; his *' De fide in
De um," 593; his views of universal
grace, 593.
Pufendorf, Samuel, 435 ; his " Ele-
menta Jurispriidentise universalis,"
436; his " De Statu imperil German-
ici," 436; his " De jure naturae et
gentium," 436; Leibnitz severely
criticises, 436.
Piinjer, his " Gesch. d. Christliche Re-
ligionsphilosophie," 298, 5S1, .'82,
584, 587, 589, 607, 7(il, 769.
Pythagoras, 379; his " Symbols." 379;
literature upon, 474.
Pythagoreans, 248.
" Quadratura Arithmetica," 425.
Qtutdriviuni, 628.
" QualitateH occult se,'' 729.
"Qualities, inexplicable," 729.
Quartan fever, 488.
"Quarto Modo, in." 455.
Question, how "begged" in the as
sumption that because we are not
conscious of ideas, therefore we do
not think, 738.
Qui jure *//o utltur nemini far if in-
, 492.
INDEX C
855
Quietists approach Averroists in doc
trine, 728.
Quintic equations, as to possibility of
their solution, 571.
Quintilian, his " Institutes," 766.
Quodlibeturias questiones, 419.
Qiiodlibetani, 419.
Qnolibet, 419.
Rabbi n age, 372.
Rabelais, 399.
Raey, Jean de, 632; his " Clavis Phil-
osophica," 633.
Ramists, 398. 408.
Ramus, Petrus, 398, 408; opposes
Aristotelianism, 408; his " Animad-
versiones Aristotelicae," 408; his
" Institutiones dialectics, " 408.
Rispe, 510, 532.
"Ratio" a department of the scho
lastic "threefold source of knowl
edge," 724.
Real and physical, their relations, 261.
Realism, Locke's sensistic, set forth in
sharp outline, 567.
Realists, 349, 382.
Reality, demonstrable, 319; how
known, 766.
Reason, how used by Locke and Leib
nitz. 555: can apprehend the super
natural as fact, 579 : and faith, 579 ;
its chief end practical, 754.
Rebus, 453.
'• Recueillernent," its translation, 165.
Refiks, 197.
Reflection, 726.
Regiomontanus, his discovery, 571.
Regis, Pierre Sylvain, an empiric Car
tesian, 348, 633; his " Cours entier '
de philosophic," 348; censured by I
Descartes, 348.
Regius, see Roy.
" Regulative," 517.
Reimarus, H. S., his " Allgemeine Be-
trachtnngen iiber die Kunsttriebe
tier Thiere," 725.
Reimer, G., 102.
Reinesius, Thomas, physician and phi
lologist, 372.
Reinkens, J. H., enquires " ' Anecdota '
sintne scripta a Procopio," 542.
Reiser, Anton, 649.
Reisland, O. K., 102.
Relation, two kinds of, 401; what?
759.
Remembrance, 734.
Reminiscence, 734; Platonic view of,
726.
Renan, E., his " Averroes et 1'Aver-
roisme," 774.
Representationism, 382.
Res, incorporates, 329; judicata, 534,
602.
Revelation, Divine, Laugley on, 32,
195: Locke assumes, 474; Leibnitz,
while insisting on rational element
in theology, admits possibility, and
discusses method and actuality, of,
474; its truth rests on " veracity of
God," 474.
Revelation, universal, 474.
Revius, J., 633.
"Revue des deux Mondes," 590.
Ritschl, his " Gesch. d. Pietismus,"
602, 649.
Robertson, G. Croom, (59; his
"Hobbes," 93, 450; his " Philos.
Remains," 733, 770.
Roberval, Gilles Personne de, 107,
127 ; his method for construction
of tangents, 108; Descartes' esti
mate of, 466.
Robinson, E. G., his " Principles and
Practice of Morality," 90, 95, 262,
752, 753, 754; his "Christian The
ology," 594, 606; his "Lectures on
Psychology" (MS.) quoted, 741-747;
on " Moral Law in its Relations to
Physical Science and to Popular Re
ligion," 761.
Rohault, James, his " Physica," 233.
Roinana rttxtica linr/m.i, 294.
Romanes, his "Animal Intelligence."
725: his " Mental Evolution in Ani
mals," 725.
Romans, 2 : 15, S9.
"Rompu, le," 750.
Rorario, Geronimo, 732.
Rothwiilsch, 292.
Roy, Hendrik van (Regius), rejected
by Descartes, 633 ; his notions of
soul, motion, and rest, 633; his
" Fundamenta Physicre " and his
" Philosophia Xaturalis," 633.
856
LEIBNITZ'S CRITIQUE OF LOCKE
Ruach (?"), defined, 289.
Ruland, Martin, his " Lexicon Al-
cheiniae," 324.
Russia, Leibnitz's plan for study of its
languages, 705.
Sabbah, Hassan Ben, 197.
Sacy, De, his " Me'nioires de 1'Insti-
tute," 197.
Sadness, its nature, 735.
Saint-Vincent, Gregoire de, his " Opus
geometricum quadrature circuli et
sectionum coni," 573.
Sainte-Maure, Charles de, edits " Del
phi n Classics," GO.").
Salmasius, 371.
Sandars, his " Institutes of Justinian,"
329, 434, 487.
Sauseverino, his " Dynamilogia," 382.
Santon, 89.
" Savage," 85.
Scaliger, Joseph Justus, reconstructs
"Chronicle of Eusebius," 100; — Jul
ius Csesar, his " Exotericse Exercita-
tiones," 106.
" Sealigerana," 107.
Schaarschmidt, 125, 128, 150, 152, 168,
214, 242, 272, 311, 316, 317, 321, 330,
339, 362, 371, 394, 399, 408, 413, 415,
424, 436, 445, 459, 4(55, 466, 476, 492,
499, 504, 510, 521, 543, 555, 569, 582,
588, 589, 590, 601, 606, 622, 623, 723,
724, 725, 72(3, 727, 728, 729, 730, 731,
733, 734, 7:35, 736, 738, 739, 741, 749,
752, 754, 755, 756, 757, 758, 759, 7(53.
Sehaff, P., edits " Xicene and Post-
Nicene Fathers," 516.
Schelling, his relation to Boehme,
298.
Schever. W., " Gesch. d. deutsch-
Literatur," 295, 296.
Schering, E. J., edits Gauss's works,
152.
Scherz and Schilter, joint editors of
"Thesaurus antiquitatum teutoni-
cum," 295.
Schilter, John, Leibnitz refers to, 295;
his death a note of time as to revi
sion of the " New Essays," 765.
Sehlee, E., his " Der Streit des Dan.
Hofmann iiber die Verhaltuiss der
Philosophie und Theologie," 582.
" Scholarch," 518.
" Scholastic, The last great," 494.
Scholastic philosophy, its threefold
source of knowledge, 724.
Schooten, F. van, 468: his " Exereita-
tiones Mathematical," 539.
Schopenhauer, 298.
Schubert, H., 425.
Schuchardt, B., 372.
Schurmau, J. G., his " Ethical Import
of Darwinism," 90, 97.
Schiirman, Anna Maria v., 602.
Schurtzfieisch, Konrad S., (550.
Schwabe, Ludwig, 244.
Schweinfurth, G. A., on men with
tails, 341; his " Im Herzen vom
Afrika," 341.
Schwei/er, his " Central-Dogmen,"
595.
" Sciences as many as truths," 623.
Scientific consideration, its limits ac
cording to Aristotle, 488.
Scotus, Johannes Major, 322 ; — Johan
nes Duns, 381 ; — Michael, 278.
Sculpturing by sense of touch, 747.
Scudery, Mile., her "Clelie, Histoire
Romaine," 223; Leibnitz on, 757.
Seckendorf, Yeit Ludwig von, his
" Commentarius historicus et apolo-
geticus de Lutheranismo," 543 ; Leib
nitz's opinion of, 544.
"Self, The," defined, 760; " the phe
nomenon of," 760; how related to
consciousness, 760 ; constitutes iden
tity, 760 ; a real entity, 760.
Selver, D., his "Der Entwicklungs-
gang d. Leibni/. Monadenlehre bis
1695," 723, 775.
Serni-Ramists, 408.
Seneca, " De Tranquilitate," 492.
Sennert, Daniel, introduces chemistry
into curriculum at Wittenberg, 487 ;
maintained that souls of animals
were immaterial, 487; his " Institu
tion es medicaj," 488; attempts to
unite principles of Galen and Para
celsus, 488.
Sensation, how related to nerves, 739.
Sense-impressions likely composite,
but at present irresolvable, 317, 751.
Sense-knowledge, confused, 317; needs
classification, 317.
INDEX C
80]
Sense-perception, when possible, 741.
Senses, when, according to Idealists,
we have truth by, 512.
Sensitive, 417; —soul, 380.
Serarius, Nicolas, 443.
Sereuus of Autissa, his " De sectione
Cylindri et Coni," 465.
Series, infinite, of Leibnitz, 424, 723.
Seth, James, his article "Roots of Ag
nosticism," in " New World," 773.
Shakespeare, his " Midsummer Night's
Dream," 770.
Shedd, W. G. T., his " History of Chris
tian Doctrine," 594.
Sheikh-al Jebal, 197.
Ship, the sacred, of the Athenians,
240.
Siebeck, his " Gesch. d. Psychologic,"
769.
Sifrid, on Frisian antiquities, 546.
Sigogne, Francois de, 107.
Sigwart, W., " Die Leibniz'sche Lehre
v. d. prastabilirten Harmonie," 731.
Simonides, inventor of mnemonics,
214.
Sleidan, John, his " Commentariorum
de statti religionis et republican,
Carolo Quinto Csesare," 114.
Sluse, Rene Francois Walter de, his
" Mesolabium," 387; his treatment
of equations of the third and fourth
degree, 387; his "perles," 768.
Smith, his "Dictionary of the Bible,"
327 ; and Wace, their "Dictionary
of Christian Biography," 345, 443,
444, 531, 618.
Societe des anciens textes francais,
Album of, 294.
Socinus, F., 593.
Socrates, 595; his dtemon, 598.
Socratic school of philosophy, 93.
Sohm, Rudolph, his "Institutes of
Roman Law," 766.
Solidity, in its conception the views
of Locke and Leibnitz come to
clearest antithesis, 741.
Souer, Ernst, 635.
Sophie Charlotte, Queen, 239.
Soul, what? 722.
Soulhood, universal, 732.
Souls, three forms of, in scholastic
philosophy, 380.
I Space defined, 152.
" Spatium fit ordo existentium phseno-
menorurn," 128.
Species, its meaning, 314; intentional,
381, 382; real, 381, 382; sensible,
381; intelligible, 381.
Specieuse genet-ale, 292, 375.
Spectroscope, the, 549.
Spencer, Herbert, 274.
Spener, Philip Jacob, 649.
Spenser, " Faerie Queen," 770.
Spermatic logos, 591.
Speusippus, 518.
Spinoza, 102, 192, 723 ; offered chair of
philosophy at Heidelberg, 102; his
"Ethica," 148, 192, 502, 732; his
" Tractatus Theologico-politicus,"
289; his fatalism, 462; letter to De
Vries, 502; maintains ontological
argument for existence of God, 502:
his " Korte Verhandeling van God,"
504, 754, 755 ; his reference to Bacon,
526; reference to Descartes, 526; on
probabilities, 539, 540 ; receives a
letter from Fabritius,723; his " Om
ni s deterrninatio est negatio," 750;
on value of faith in a future life
upon this one, 755: monism of, 757.
| Spirits incomprehensible to senses and
imagination, 721 ; of the elements,
730.
] Spiritual things prior to material, 721.
' Spiritus, 289 ; naturae, 382,768": /«-
miliaris, 730.
Spitzel, Theophil Gottlieb, 649.
Spontaneity of soul, 733.
Sprengel, K., his " Beitrage z. Gesch.
des Medecin," 408; on Sennert, 4S8.
Stamm, his " Ulfilas," 296.
Stegmann, Christopher, his " Dvas
Philosophica," 585; — Joachim,
mathematician and theologian, ;>5;
— Joshua, his " Ach bleib' mit
deinem gnade," 586.
Stein, Ludwig, his " Leibniz und
Spinoza," 69, 102, 242, 349, 504, <;.r»L',
653, 655, 731 .
Steinthal, H., his " Einleitung in die
Psychologic und Sprach-wissen-
schaft," 292.
Stephanus, his '' Thesaurus Linguae
' 476.
858
LEIBNITZ'S CRITIQUE OF LOCKE
Stewart, J. A., his " Notes on the Nico-
machean Ethics of Aristotle," 753.
Stillingrleet, Bishop Edward, 54; con
troversy with Locke, 54, 55, 56.
Stobfeus, " Eclogae Physicae," 518.
Stockl, his " Gesch. d. Philos. d. Mittel-
alters," 116, 278, 298, 349, 380, 382,
408, 415, 421, 494, 503, 566, 581, 588,
590, 592, 632, 635, 645, 646, 730, 732.
Stoic philosophers, 261, 729.
" Stomachi Janitor," 67.
Strabo, his " Geographica," 345; on
fertility of mules, 345.
Strauch, Johann, his "Lexicon parti-
cularum juris," etc., 365.
" Strong-minded," 728.
St.ru ve, F. W., edits the " Bibliotheca
juridica " of Lipenius, 626,
Struyck, Nicolas, on De Witt's reason
ing on Insurance, 540; his " Inlei-
ding tot het algemeine geography,"
540.
Sturm, Johann Christoph, 705.
Suarez, Francisca, his "De Anima,"
382; his "Tract, de legibus ac Deo
legislatore," 494.
Substance, idea of the individual, its
development in mind of Leibnitz,
101 ; list of Leibnitz's papers on,
154 : what, according to Leibnitz,
227 ; what, according to Aristotelian
scholasticism, 227 ; changing yet nu
merically the same, 243 ; first in
sense of Aristotle, 311 ; first, IT purr/
ova-La, 311, 34!); corporeal, what? 722;
its absolute spontaneity, 739 ; opin
ions of Locke and Leibnitz regard
ing, 749 ; Leibnitz, in speaking of,
accommodates himself to linguistic
usage, 759 : Leibnitz's view of, 760.
" Succedaneum," 417.
SiAXo7io>6s, two kinds of, 565.
Sulpicius Severus, 345.
, 453.
ce, 47(5.
^vjjiirvovs, universe, 476.
Supernatural, its relation to reason,
579. '
Surd, an obsolete mathematical term,
750.
Suter, H., his " Gesch. d. math. Wis-
senschafteu," 527.
i Swift, his "Gulliver's Travels," 342;
did he plagiarize? 399.
! Syllogism, fourth figure of, 408; all
its terms not always expressed in'
argumentation, 481; dialectic, 564;
apodeictic, 565.
I Symonds, J. A., his "Studies of the
Greek Poets," 211, ibid. 3d ed., 755 ;
his "Renaissance in Italy," 399,
415.
Synthesis, explained by Pappus, 521.
" System, New," commented on, 731.
"Tabula," " logica," 322; "rasa, "724.
Tacitus, "Annales," 91, 327.
Tails, men with, 341.
Tartaglia, his contest with Fiore, 572.
j Taste through nose, 739, 740.
Taylor, Thomas, 108.
Technical schools advocated by Leib
nitz, 628.
Teeth transmit sound ? 740.
Temperament, what? 362.
I " Ternpus fit ordo successivorum," 128.
j Ten Brink, B., his " Early English Lit
erature," 295.
Teotisca, lingua, old German, 294.
Terence, "Andria," 226: " Phormio,"
327; "Eunuchus," 459; " Heauton-
timoromnenos," 492.
Term, middle, 481 ; the general, 511.
Terminism, 588.
Tertullian, 531; his " De Pr»3scripti-
one Hsereticorum," 531: his " De
Carne Christi," 582: his " credibile
est quia inept um est," etc., 582.
Teuffel, his "Gesch. d. Rom. Lit.,"
244.
j Thales, 463.
" Thendicee, Essais de," see Leibnitz.
! Theology, Natural, made a depart
ment of Metaphysics by Scholastics,
496.
Theophrastus adds to first figure of
the Syllogism, 408.
I " Theseus, ship <>C' 240.
! Thil, Arnaud du, the personator of
Martin Guerre, 310.
! Thomas, the Pseudo-, 322.
Thomasius, G., his "De Controversia
Hoffrnanniana," 582; — Jacob, pro
fessor of Philosophy at Leipzig,
INDEX C
859
605; his "De officio hominis circa
notitiam futurorum contingenti-
um," 606; his " Origin es historise
philosophies et ecclesiasticae," 606;
— Christian, son of above, and ed
itor of his works, 606.
Thompson, Archbishop, 455.
Thorpe, B., his " Caedmon's Metrical
Paraphrase," 295.
Thought, objects of, classified, 148;
right, leads back to God, 505 ; may be
distinct, yet not clear, 754 ; how the
word is employed by Leibnitz, 756.
" Thought-necessity," 281.
Tichborne case, 310.
Time, defined, 128 ; — of writing " New
Essays," 532; of revising "New
Essays," 765.
Tiraboschi, his " Storia della Lettera-
ttira Italiana," 415, 593.
Todhunter, Isaac, his " History of the
Theory of Probability from Pascal
to La Place," 213, 539.
Tolomei, Giovanni Battista, 705.
Tonnies, F., his " Leibniz unu
Hobbes," 4.~0.
Torricelli, Evangelista, invented mer
curial barometer, 127: discovered
quadrature of cycloid, 127; his "De
motu gravium naturaliter accele-
rato," 127.
" Tot scientise quot veritates," 623.
" Transcendent " in mathematics, 750.
Trebatius, 492.
Trendelenl)urg, his " Ueber Leibniz-
ens Entwurf einer allgemeinen Char-
akteristik," 292, 375; his "Ueber
d. element d. definition in Leibniz.
Philosophie," 317 ; his " Histor. Bei-
triige z. Philos.," 753, 765.
Trent, Council of, 114.
Trew, Abdias, 641.
Trino, the Decurions of, 520.
Trithemius, his "Annales Hirsaugien-
ses," 278; his "Compendium primi
volurninis annalium de origine re-
rum et gentis Francorum," 546.
Trivium, 628.
True, the, is the thinkable, 281.
Truth, Aristotle on, 281 : of two kinds,
404; Leibnitz on its definition, 445 ;
Locke's and Leibnitz's views of,
452; Schaarschmidt's definition of,
762.
"Truth, twofold," the, 581.
Truths, of fact and of reason, 462,
493; of reason, their genesis, 725;
necessary, 725 ; factual, 725.
I Tulloch, his "Rational Theology and
Christian Philosophy in England in
17th Century," 767.
| Tulp, Nicolas, his " Observation um
Medicarum," 244.
| Tutiorism, 418.
| "Twofold Truth, "581.
! Ueberweg, his "Hist, of Philosophy,"
116, 332, 763, 769: his " Grundriss
der Gesch. der Philosophie," 5;
-Heinze, 332, 408, 503, 516, 592.
| Ulfilas, 296.
j Ulpianus, 486.
j Ulrich, J. H. F., German translator
of the French and Latin works of
Leibnitz, Raspe's ed., 344.
" Unconscious Mental States," 727.
" Un Je ne say quoi," 12S.
ITncle of Leibnitz, 365.
: "Understanding," 723. [310.
Universal, the, does it really exist?
! Universe not a whole, 155.
Uppstrom, edits "Codex Argenteus,"
296.
Ursinus, Joseph, 767.
! Utile and honestum, 261.
Uylenbroek, P. I., 767; his "Christ.
Hugenii aliorumque celebrium exer-
citationes mathematics et philo-
sophieae," 767.
1 Vacuum, Descartes' view of, 127 ; for-
marum, 334 ; defined, 740.
Valla, Laurentius, explodes the alleged
"Donation of Constantine," 415;
his " Disputationes contra Aristote-
licos," 415; his " De voluptate et
vero bono," 415 ; his " Libero arbit-
rio " ; his " Elegantise Latinse Lin-
guai," 415.
[ Van Helmont, 67, 242.
| Vanini, Lucilio, 648.
I Vassan , 107.
! Vaughan, Alfred, his " Hours witli the
Mystics," 298.
8(10
LEIBNITZ'S CRITIQUE OF LOCKE
Vayer, Francois de la Mothe le, his
" De la Vertu des Pa'iens," 593.
Vedelius, 587; his "Rationale Theo-
logieum," 587; his controversy with
Musaws, 587, 7(51.
Vega, Garcilasso de la, his " Commen-
tarios Reales," 89.
" Vegetative soul," the, 380.
" Vehicles, aerial," of spirits, 380.
Veitch, J., translator of Descartes,
127, 348, 483.
Velleitas, 168.
Velleite, its rendering, 168.
Venn, J., his " Logic of Chance," 214.
Venturi, his " Commentarii sopra la
storia et le teorie dell' ottica," 443.
Vergil, his " Georgics," 200, 211, 727;
"^Eneid," 300, 415, 598, 614; "Ec
logues," 614.
" Vernunft, die," its Kantian accepta
tion, 723.
Versura, 326.
Vertunien, Francois, 107.
Verulamius, 526.
Vibration Theory of Light, 639.
Viete, Francois, 468 ; his improve
ments in algebraical operations, 468 ;
lays down the principle of " homo
geneity," 468 ; his "Opera mathe-
matica," 468.
Vincent of Lerins, his " Ad versus
novitates hsereticorum commonito- ;
rium," 617; author of the dictum, j
"Quod semper, quod ubique, quod
ab omnibus creditum est," 617.
Viotto, Bartolommeo, his " De balne- ;
orum riaturalium viribus," 520 ; his j
" Demonstrationum in methodum
medendi," 520: Conring's opinion >
of, 520.
Virgil, St. (Fergil), 443.
"Virtual," 726.
Virtue, ou what its usefulness de
pends, 495 ; Kant's definition of, 754 ; !
E. G. Robinson's definition of, 754. ;
Vision, the Beatific, its nature, 575; '
history of idea, 575.
Voet-Schoock-Descartes controversy, !
633.
Volitio imperfecta, 168.
Voltaire in the Maupertuis-Konig con
troversy, 713.
Vopiscus, in " Scriptores Hist. Au
gust.," 263, 761.
" Vorstelleu," 756.
" Vorstellung," 330, 736, 756.
Vortices, theory of, according to Des
cartes, 552, 613, 727.
Vossins. Isaac, 107.
Waitz, his "Das Leben des rifilas,"
296.
Wallace, E., his "Outlines of the Phi
losophy of Aristotle," 96, 156, 157,
214, 281, 291, 311, 312, 320, 321, 349,
421, 488, 565, 751, 770; his "Aris
totle's Psychology in Greek and
English," 281, 321 ; — \V.f his " Epi
cureanism," 421; his "Logic of
Hegel," 750, 766.
Wallis, John, 677.
Walpole. F., his "Ansayrii," 197.
Walton, Isaac, 566.
Warr, G. C. W., 244.
Watson, John, his "Philosophy of
Kant in Extracts," 128; his article
"Leibnitz and Protestant The-
°logy,'' in " New WTorld," 770, 773.
" Weaker or Worse," in Logic, 515.
Weigel, Erhard, engaged on Calendar,
435 ; a school reformer, 435 ; his
" Arithmetique de la Morale," 435;
Leibnitz upon, 435.
Weil, his " Gesch. d. Chalifen," 197.
Werner, K., his " Suarez," 494.
Wetzer und Welte, their " Kirchen-
lexicon," 600.
White, Thos. (Anglus), 634; his " In-
stitutionum Peripateticarum ad
mentem K. DigbaM," 634: his "De
Medio Animarum Statu,"775; cen
sured by Parliament, 775; his " Ke-
sponsio ad duos theologos de Medio
Animarum Statu," 775.
Whitney, AV. D., his "Language and
the Study of Language," 291, 292.
Wilkin, "Gesch. d. Kreuzziige," 197.
Wilkins, Bishop -John, his " P'ssay
towards a Real Character and a
Philosophical Language," 292.
" Will, vigor of," 754.
Willensneiyung, 168.
AVillkiir, 752.
AViudelband, his "History of Philos-
INDEX C
861
ophy," 488, 502, 503, 516, 570, 581,
588, 724, 727, 732, 733, 753.
Winer, his " Handbucli d. Theol. Lit.,"
581), 587.
Wint'rid, see Boniface.
Wisdom, Leibnitz's definition, 754.
Witsen, Nicolas, sends specimens of
the language of the Hottentots to
Leibnitz, 290; his " Architectonica
nautica non-antiqua," 71)7.
Witt, John De (Pensionary), 426; his
" Elementa linearum curvorum,"
427; his report on annuities to
States-General, 540.
Wohlwill, E., his " Jurigius," <i36.
Wolf, Christian, 303; his " Kurzer
Unterricht v. d. vornehmsten math.
Schrift," 463; made existence the
source of its concept, 741 ; ac
cepts Leibnitz's definition of truth,
763; his definition of philosophy,
763; his " Psychologia Empirica,"
764.
Wolffhart, Conrad (Lycosthenes),
548.
World-soul, 732.
Wrangham, D. S., his " Liturgical
Poetry of Adam St. Victor," 603.
Wren, Sir Christopher, 346, 677.
Wright, J., his "Primer of Gothic,"
296.
Wundt, William, his " Lectures on
Human and Animal Psychology,"
725.
Xenocrates, 518.
Xenophon, "Memorabilia," 240.
Xylander, 571.
Yvon, Pierre, his " Abrege precis de
la vie et de la conduite et des vrais
sentiments de feu M. de Labadie,"
602.
Zabarella, Jacopo, 635.
Zachary, Pope, 444.
Zeller, his " Outlines of the History of
Greek Philosophy," 65, 93, 96, 108,
156; his "Philos. d. Griech.," 108,
156, 261, 277, 285, 311, 312, 320, 321,
349, 3(52, 379, 383, 408, 421, 436, 463,
4(55, 474, 488, 496, 518, 519, 565, 576,
598, 724, 750, 751, 753; " Gesch. d.
deutschen Philos.," 363.
Zigliara, his " Summa Philosophica,"
382.
Ziminermann, his "Leibniz und Les-
sing," 584.
Zwerger, M., his " Die lebendige Kraft
und ihr Mass," 775.
Zwinger, Theodore, 311; his " Thea-
truin Vitre Humanae," 548.
Zwingli, Ulrich, 592, 595 ; his "Christ
Fidei brevis et clara expositio," 595;
his " De Providentia," 5. 5.
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