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DISCOURSE

METHOD OF RIGHTLY CONDUCTING

THE REASON, AND SEEKING

TRUTH IN THE SCIENCES

RENE DESCARTES

TRANSLATED FROM THE FRENCH AND COLLATED WITH
THE LATIN BY

JOHN VEITCH, LL.D

LATE PROFESSOR OF LOGIC AND RHETORIC JI» IGT
UNIVERSITY OF GLASGOW

AUTHORIZED REPRINT

THE OPEN COURT PUBLISHING COMPANY
LA SALLE ILLINOIS

NOV 1 5 1966

o* /]

^

or

1139360

Printed in the United States of America

for the Publishers by

Paquin Printers

PUBLISHERS' PREFACE.

DESCARTES' Discourse on Method was published in Leyden,
in 1637, and was accompanied by three brief tracts as appendices :
the Geometry, the Meteor ics, and the Dioptrics.

The Discourse on Method was Descartes' intellectual confes
sion of faith, his statement of his own peculiar method of reaching
the Truth ; the appendices were his documents of justification,
specimens of the actual Truth that he had reached by his method.
And splendid specimens they were : the invention of analytical
geometry, which literally unshackeled mathematical research ; the
researches in the theory of equations and algebraical symbolism ;
the enunciation of the law of the refraction of light, which is the
beginning of the development of modern optics ; the partial ex
planation of the rainbow ; and so forth. All these achievements,
far as they may seem from the common life, are shot througn the
warp and woof of our technical civilisation, and our entire spiritual
and material existence bears their hidden impress.

Whether our calling, therefore, be that of a philosopher or
not, and whatever be our attitude to the problems involved, the
contemplation of the methods by which such unique results have
been reached is of the highest concern. No one can fail to draw
a most bountiful stimulus from these pages. Their freshness
and independence of view, their wholesome common sense, their
self-reliance, their apotheosis of Reason, are, when we consider
the state of mind of the period in which they were written, almost
unequalled in history. Here was an absolute break with the
authority of tradition, an utter rejection of the past, an utter con
tempt of books, of the graces of literature and of erudition ; while
in their place were substituted the ideals of radical doubt, impla
cable critique, unerring certainty. Truth was no longer a "plural
ity of suffrages," the utterance of an Aristotle or a Pope; it was

iv PUBLISHERS' PREFACE.

the outcome of right thinking and right seeing, the privilege of
every man. The appeal throughout was made to " the great book
of the world," to experiment, to observation. " Here is my library,"
said Descartes to an inquirer, as he pointed to a quartered calf he
was busy dissecting.

Such an attitude would be impossible now ; the present age
has a real past of science behind it. But it was necessary then ;
the past which lay directly behind Descartes, with a few bright
exceptions like Bruno and Campanella, was a past of slavish sub
mission to authority, both in action and in thought ; and the utter
demolition of this past was the self-chosen task of the great recluse-
philosopher, who believed he had stript himself of every clog that
the heritage of antiquity had placed upon man's intellect.

And here lies both the virtue and defect of his system. Des
cartes was primarily a mathematician. He found in mathematics,
as did Kant and Comte, the type of all faultless thought — not in
the traditional mathematics as such, but in mathematics as regen
erated and inspirited by his own epoch-making discoveries. The
geometrical analysis of Plato and the ancients was, at best, a hap
hazard procedure, depending almost entirely on the insight and
skill of the manipulator, concerned for the logic rather than for
the power of the method, and yielding in almost all cases isolated
results, not general and comprehensive truths. But the method
of Descartes was an engine of research ; it reduced geometry largely
to algebra ; of the science of the eye it made a science of the mind ;
from a part it deduced a whole ; for the rich exuberance of nat
ural forms it substituted the economy and precision of a purely
logical mechanism. Was he not justified, therefore, in pointing
with pride to the maxims and rules by which his mediocre talents,
as he termed them, had been enabled to advance the truth so
powerfully ? He was on the verge of a universal Mathematical
Science, why was it not possible to construct a Universal Formal
Science, manipulable with the same mechanical precision, and ap
plicable to physics, chemistry, cosmology, biology, psychology,
and theology ? Why was it not possible to deduce God, man, and
society from a few simple fundamental truths, as the properties of
a curve were developable from an algebraical equation ?

Hence resulted the Cartesian physics and metaphysics, half

PUBLISHERS' PREFACE. V

child of the science that he vaunted, half child of the dead tradi
tion that he detested ; for he had not stript himself entirely of the
past. That is possible for no man.

Descartes stopped at Faith. His metaphysics was a rational
ised theology, in which everything was merged in God, — a theistic
monism. His psychology, his theory of the soul, were dualistic.
Yet, despite their crudeness from the modern view, they were an
advance, and despite their author's seeming submissiveness to the
teachings of the Church, they were placed with his other doctrines
on the Index. The very search for a "criterion of truth" was
sufficient to condemn his system.

But there was, in this action of the Church, a presage of the
disintegrating character of the new doctrines. Descartes' physics
practically nullified his theology, but he was careful not to give
offence. With the fate of Bruno, Campanella, and Galileo before
his eyes, he naturally felt, as a recent writer expresses it, "no
vocation for martyrdom." Nonetheless he pushed his mechanical-
ism to the extreme, and carried it to the very throne of his God,
engulfing all nature and all life. With motion and extension alone,
supported by the laws of geometry, he constructed the Universe.
The construction was largely a friori and was in defiance of the
experimental principles that he so highly lauded, and in contra
diction to the real mechanics that Galileo had just discovered and
which Descartes mistook, but it contained most of the theoretical
elements of the modern mechanical explanation of nature, and its
main hypotheses, as the theory of vortices, the uniform constitu
tion of matter, etc., have persisted to this day. His ideas were,
thus, more powerful than even his own application of them, and
in the hands of his successors led to the undermining of the very
Faith which, from prudence or conviction, he himself had desired
to leave untouched.

His system, even now, as shattered by modern research, and
in its ruins, with the towers of its real achievements projecting
aloft, presents a magnificent spectacle, daring in its scope and
execution. The defects of its construction are to be measured by
the standard of its time, not by the standard which through its
assistance succeeding centuries have been enabled to establish. If
it appears repellent in its aspect, harsh in its rigor, it must be re-

VI PUBLISHERS' PREFACE.

membered that it came from a man to whom " there was no beauty
but the beauty of truth," and to whom the natural severity of sci
ence was the proudest adornment of civilisation, and redounded
most surely to the enhancement of real, practical life.

Descartes, it has been said, is the cross-roads from which the
modern paths of thought diverge. He was the forerunner of New
ton and Leibnitz on the one hand, and of Hume and Kant on the
other. The picture presented in this book, of his mental auto
biography, is one of the most pleasing chapters of the history of
philosophy. It belongs to the world, from the great heart of
which it sprung, free from the mustiness of the study ; and its
candor and manliness of view cannot, even now when most of it
has become commonplace, and some of it antiquated, fail to arouse
the apathy of a people who are hungering for enlightenment.

To make it more accessible to the people, is our purpose in
re-publishing it. The translation is by the late Dr. Veitch, of the
University of Glasgow, whose representatives have authorised the
reprint, and to whose Introduction in the volume published by
Blackwoods we may refer the student for a detailed analysis of
Descartes' philosophy. A more general treatment will be found in
Levy-Bruhl's new History of Modern Philosophy in France*
For further literature the reader is referred to the Bibliography at
the end of the text.

THOMAS J. MCCORMACK.
LA SALLE, ILLS., August, 1899.

*Thc Open Court Publishing Company, Chicago.

NOTE.

Since the appearance of the first edition of this reprint, Veitch's trans
lation of Descartes's Meditations on the First Philosophy has also been pub
lished in the present series of Philosophical Classics. The same volume also
contains translations of parts of the Principles of Philosophy, and of part of
Descartes's Reply to the Second Objections, and is prefaced by Ldvy-Bruhl's
essay on Descartes's Philosophy.

[PREFATORY NOTE BY THE AUTHOR.]

IF this Discourse appear too long to be read at
once, it may be divided into six parts : and, in the
first, will be found various considerations touching
the Sciences; in the second, the principal rules of
the Method which the Author has discovered; in the
third, certain of the rules of Morals which he has
deduced from this Method ; in the fourth, the rea
sonings by which he establishes the existence of
God and of the Human Soul, which are the founda
tions of his Metaphysic, in the fifth, the order of
the Physical questions which he has investigated,
and, in particular, the explication of the motion of
the heart and of some other difficulties pertaining
to Medicine, as also the difference between the soul
of man and that of the brutes ; and, in the last, what
the Author believes to be required in order to
greater advancement in the investigation of Nature
than has yet been made, with the reasons that have
induced him to write.

Discourse on Method.

PART I.

GOOD SENSE is, of all things among men, the most
equally distributed ; for every one thinks himself so
abundantly provided with it, that those even who
are the most difficult to satisfy in everything else,
do not usually desire a larger measure of this quality
than they already possess. And in this it is not
likely that all are mistaken : the conviction is rather
to be held as testifying that the power of judging
aright and of distinguishing Truth from Error,
which is properly what is called Good Sense or
Reason, is by nature equal in all men; and that the
diversity of our opinions, consequently, does not arise,
from some being endowed with a larger share of
Reason than others, but solely from this, that we
conduct our thoughts along different ways, and do
not fix our attention on the same objects. For to!
be possessed of a vigorous mind is not enough; the V
prime requisite is rightly to apply iU The greatest )
minds, as they are capable of the highest excel
lencies, are open likewise to the greatest aberra-

2 DESCARTES.

tions; and those who travel very slowly may yet
make far greater progress, provided they keep
always to the straight road, than those who, while
they run, forsake it.

For myself, I have never fancied my mind to be
in any respect more perfect than those of the gener
ality; on the contrary, I have often wished that I
were equal to some others in promptitude of
thought, or in clearness and distinctness of imagi
nation, or in fulness and readiness of memory.
And besides these, I know of no other qualities that
contribute to the perfection of the mind ; for as to
•the Reason or Sense, inasmuch as it is that alone
which constitutes us men, and distinguishes us from
the brutes, I am disposed to believe that it is to be
found complete in each individual ; and on this point
to adopt the common opinion of philosophers, who
say that the difference of greater and less holds only
among the accidents, and not ampag^the forms or
natures of individuals of the §z.-m<£spt;ies?\

I will not hesitate, however, to 3V6w my belief
that it has been my singular good fortune to have
very early in life fallen in with certain tracks which
have conducted me to considerations and maxims,
of which I have formed a Method that gives me the
means, as I think, of gradually augmenting my know
ledge, and of raising it by little and little to the high
est point which the mediocrity of my talents and the
brief duration of my life will permit me to reach.
For I have already reaped from it such fruits thal^
although I have been accustomed to think Jowlv
enough of myself, and although when I look witn

DISCOURSE ON METHOD. 3

the eye of a philosopher at the varied courses and
pursuits of mankind at large, I find scarcely one
which does not appear vain and useless, I neverthe
less derive the highest satisfaction from the progress
I conceive myself to have already made in the
search after truth, and cannot help entertaining
such expectations of the future as to believe that if,
among the occupations of men as men, there is any
one really excellent and important, it is that which
I have chosen.

After all, it is possible I may be mistaken ; and it
is but a little copper and glass, perhaps, that I take
for gold and diamonds. I know how very liable we
are to delusion in what relates to ourselves, and also
how much the judgments of our friends are to be
suspected when given in our favour. But I shall
endeavour in this Discourse to describe the paths I
have followed, and to delineate my life as in a pic
ture, in order that each one may be able to judge of
them for himself, and that in the general opinion
entertained of them, as gathered from current
report, I myself may have a new help towards
instruction to be added to those I have been in the
habit of employing.

My present design, then, is not to teach the

Method which each_ought to follow for Jthe right con
duct of his reason, but solely to describe the way in
which I have endeavoured to conduct my own.
They who set themselves to give precepts must of
course regard themselves as possessed of greater
skill than those to whom they prescribe; and if they
err in the slightest particular, they subject them-

4 DESCARTES

selves to censure. But as this Tract is put forth
merely as a history, or, if you will, as a tale, in
which, amid some examples worthy of imitation,
there will be found, perhaps, as many more which
it were advisable not to follow, I hope it will prove
useful to some without being hurtful to any, and
that my openness will find some favour with all.

From my childhood, I have been familiar with
letters; and as I was given to believe that by their
help a clear and certain knowledge of all that is use
ful in life might be acquired, I was ardently desirous
of instruction. But as soon as I had finished the
entire course of study, at the close of which it is
customary to be admitted into the order of the
learned, I completely changed my opinion. For I
found myself involved in so many doubts and
errors, that I was convinced I had advanced no
farther in all my attempts at learning, than the dis
covery at every turn of my own ignorance. And
yet I was studying in one of the most celebrated
Schools in Europe, in which I thought there must
be learned men, if such were anywhere to be found.
I had been taught all that others learned there ; and
not contented with the sciences actually taught us,
I had, in addition, read all the books that had fallen
into my hands, treating of such branches as are
esteemed the most curious and rare. I knew the
judgment which others had formed of me; and I did
not find that I was considered inferior to my fel
lows, although there were' among them some who
were already marked out to fill the places of our
instructors. And, in fine, our age appeared to me

DISCOURSE ON METHOD. 5

as flourishing, and as fertile in powerful minds as
any preceding one. I was thus led to take the
liberty of judging of all other men by myself, and of
concluding that there was no science in existence
that was of such a nature as I had previously been
given to believe.

I still continued, however, to hold in esteem the
studies of the Schools. I was aware that the Lan
guages taught in them are necessary to the under
standing of the writings of the ancients ; that the
grace of Fable stirs the mind ; that the memorable
deeds of History elevate it ; and, if read with dis
cretion, aid in forming the judgment; that the
perusal of all excellent books is, as it were, to
interview with the noblest men of past ages, who
have written them, and even a studied interview, in
which are discovered to us only their choicest
thoughts; that Eloquence has incomparable force
and beauty ; that Poesy has its ravishing graces and
delights; that in the Mathematics there are many
refined discoveries eminently suited to gratify the
inquisitive, as well as further all the arts and lessen
the labour of man; that numerous highly useful
precepts and exhortations to virtue are contained in
treatises on Morals; that Theology points out the
path to heaven ; that Philosophy affords the means
of discoursing with an appearance of truth on all
matters, and commands the admiration of the more
simple; that Jurisprudence, Medicine, and the other
Sciences, secure for their cultivators honours and
riches ; and, in fine, that it is useful to bestow some
attention upon all, even upon those abounding the

6 DESCARTES.

most in superstition and error, that we may be in a
position to determine their real value, and guard
against being deceived.

But I believed that I had already given sufficient
time to Languages, and likewise to the reading of
the writings of the ancients, to their Histories and
Fables. For to hold converse with those of other
ages and to travel, are almost the same thing. It is
useful to know something of the manners of jd|ffer-

Jbe__Able to form

correct judgment regarding our .own, .and be
vented from thinking that everything contrary :ti>
our customs- is ridiculous and irrational, — a con
clusion usually come to by those whose experience
has been limited to their own country. On the
other hand, when too much time is occupied in
travelling, we become strangers to our native
country; and the over curious in the customs of the
past are generally ignorant of those of the present.
Besides, fictitious narratives lead us to imagine the
possibility of many events that are impossible ; and
even the most faithful histories, if they do not
wholly misrepresent matters, or exaggerate their
importance to render the account of them more
worthy of perusal, omit, at least, almost always the
meanest and least striking of the attendant circum
stances; hence it happens that the remainder does
not represent the truth, and that such as regulate
their conduct by examples drawn from this source,
are apt to fall into the extravagances of the knight-
errants of Romance, and to entertain projects that
exceed their powers.

DISCOURSE ON METHOD. 7

I esteemed Eloquence highly, and was in raptures
with Poesy ; but I thought that both were gifts of
nature rather than fruits of study. Those in whom
the faculty of Reason is predominant, and who
most skilfully dispose their thoughts with a view to
render them clear and intelligible, are always the
best able to persuade others of the truth of what
they lay down, though they should speak only in the
language of Lower Brittany, and be wholly ignorant
of the rules of Rhetoric; and those whose minds are
stored with the most agreeable fancies, and who can
give expression to them with the greatest embellish
ment and harmony, are still the best poets, though
unacquainted with the Art of Poetry.

I was especially delighted with the Mathematics,
on account^pf the certitude JandTevidence oTTheir
reasonings^, but I had not as~ yet a precise know4-
edge of their true use; and thinking that they but
contributed to the advancement of the mechanical
arts, I was astonished that foundations, so strong
and solid, should have had no loftier superstructure
reared on them. On the other hand, I compared
the disquisitions of the ancient Moralists to very-
towering and magnificent palaces with no better
foundation than sand and mud: they laud the
virtues very highly, and exhibit them as estimable
far above anything on earth ; but they give us no
adequate criterion of virtue, and frequently that
which they designate with so fine a name is but
apathy, or pride, or despair, or parricide.

I revered our Theology, and aspired as much as
any one to reach heaven: but being given assuredly

8 .DESCARTES.

to understand that the way is not less open to the
most ignorant than to the most learned, and that the
revealed truths which lead to heaven are above our
comprehension, I did not presume to subject them to
the impotency of my Reason ; and I thought that in
order competently to undertake their examination,
there was need of some special help from heaven,
and of being more than man.

- Of Philosophy I will say nothing, except that
when I saw that it had been cultivated for many
ages by the most distinguished men, and that yet
there is not a single matter within its sphere which
is not still in dispute, and nothing, therefore, which
is above doubt, I did not presume to anticipate that
my success would be greater in it than that of
others ; and further, when I considered the number
of conflicting opinions touching a single matter that
may be upheld by learned men, while there can be
but one true, I reckoned as well-nigh false all that
was only probable.

As to the other Sciences, inasmuch as these bor
row their principles from Philosophy, I judged that
no solid superstructures could be reared on founda
tions so infirm ; and neither the honour nor the gain
held out by them was sufficient to determine me to
their cultivation : for I was not, thank heaven, in a
condition which compelled me to make merchandise
of Science for the bettering of my fortune; and
though I might not profess to scorn glory as a
Cynic, I yet made very slight account of that honour
which I hoped to acquire only through fictitious
titles. And, in_fine^ of__false_ Sciences- I-thougfct -I

DISCOURSE ON METHOD. 9

knew the worth sufficiently to escape being deceived
by the professions of an alchemist, the predictions
of an astrologer, the impostures of a magician, or
by the artifices and boasting of any of those who
profess to know things of which they are ignorant.
For these reasons, as soon as my age permitted
me to pass from under the control of my instructors,
I entirely abandoned the study of letters, and
resolved no longer to seek any other science than
the knowledge of myself, or of the great book of the
world. I spent the remainder of my youth in
travelling, in visiting courts and armies, in holding
intercourse with men of different dispositions and
ranks, in collecting varied experience, in proving
myself in the different situations into which fortune
threw me, and, above all, in making such reflection
on the matter of my experience as to secure my
improvement. For it occurred to me that I should find
much more truth in the reasonings of each individual
with reference to the affairs in which he is person
ally interested, and the issue of which must pres
ently punish him if he has judged amiss, than in
those conducted by a man of letters in his study,
regarding speculative matters that are of no prac
tical moment, and followed by no consequences to
himself, farther, perhaps, than that they foster his
vanity the better the more remote they are from
common sense ; requiring, as they must in this case,
the exercise of greater ingenuity and art to render
them probable. In addition, I had always a most
earnest desire to know how to distinguish the true
from the false, in order that I might be able clearly

IO DESCARTES.

to discriminate the right path in life, and proceed
in it with confidence.

It is true that, while busied only in considering
the manners of other men, I found here, too, scarce
any ground for settled conviction, and remarked
hardly less contradiction among them than in the
opinions of the philosophers. So that the greatest
advantage I derived from the study consisted in
this, that, observing many things which, however
extravagant and ridiculous to our apprehension, are
yet by common consent received and approved by
other great nations, I learned to entertain too
decided a belief in regard to nothing of the truth of
which I had been persuaded merely by example and
custom: and thus I gradually extricated myself
from many errors powerful enough to darken our
Natural Intelligence, and incapacitate us in great
measure from listening to Reason. But after I had
been occupied several years in thus studying the
book of the world, and in essaying to gather some
experience, I at length resolved to make myself an
object of study, and to employ all the powers of my
mind in choosing the paths I ought to follow; an
undertaking which was accompanied with greater
success than it would have been had I never quitted
my country or my books.

PART II.

I WAS then in Germany, attracted thither by the
wars in that country, which have not yet been brought
to a termination ; and as I was returning to the army
from the coronation of the Emperor, the setting in
of winter arrested me in a locality where, as I found
no society to interest me, and was besides fortu
nately undisturbed by any cares or passions, I
remained the whole day in seclusion,* with full
opportunity to occupy my attention with my own
thoughts. Of these one of the very first that
occurred to me was, that there is seldom so much
perfection in works composed of many separate
parts, upon which different hands have been
employed, as in those completed by a single master.
Thus it is observable that the buildings which a
single architect has planned and executed, are gener
ally more elegant and commodious than those which
several have attempted to improve, by making old
walls serve for purposes for which they were not
originally built. Thus also, those ancient cities
which, from being at first only villages, have
become, in course of time, large towns, are usually
but ill laid out compared with the regularly con
structed towns which a professional architect has

* Lite rally, in a room heated by means of a stove. — 2>.

II

12 DESCARTES.

freely planned on an open plain ; so that although
the several buildings of the former may often equal
or surpass in beauty those of the latter, yet when
one observes their indiscriminate juxtaposition,
there a large one and here a small, and the conse
quent crookedness and irregularity of the streets,
one is disposed to allege that chance rather than any
human will guided by reason, must have led to such
an arrangement. And if we consider that neverthe
less there have been at all times certain officers
whose duty it was to see that private buildings con
tributed to public ornament, the difficulty of reach
ing high perfection with but the materials of others
to operate on, will be readily acknowledged. In the
same way I fancied that those nations which, start
ing from a semi-barbarous state and advancing to
civilisation by slow degrees, have had their laws
successively determined, and, as it were, forced
upon them simply by experience of the hurtfulness
of particular crimes and disputes, would by this proc
ess come to be possessed of less perfect institutions
than those which, from the commencement of their
association as communities, have followed the
appointments of some wise legislator. It is thus
quite certain that the constitution of the true reli
gion, the ordinances of which are derived from God,
must be incomparably superior to that of every
other. And, to speak of human affairs, I believe
that the past pre-eminence of Sparta was due not to
the goodness of each of its laws in particular, for
many of these were very strange, and even opposed
to good morals, but to the circumstance that, orig-

DISCOURSE ON METHOD. IJ

Inated by a single individual, they all tended to a
single end. In the same way I thought that the
sciences contained in books, (such of them at least
as are made up of probable reasonings, without
demonstrations,) composed as they are of the opin
ions of many different individuals massed together,
are farther removed from truth than the simple
inferences which a man of good sense using his nat
ural and unprejudiced judgment draws respecting
the matters of his experience. And because we
have all to pass through a state of infancy to man
hood, and have been of necessity, for a length of
time, governed by our desires and preceptors,
(whose dictates were frequently conflicting, while
neither perhaps always counselled us for the best,) I
further concluded that it is almost impossible that
our judgments can be so correct or solid as they
would have been, had our Reason been mature from
the moment of our birth, and had we always been
guided by it alone.

It is true, however, that it is not customary to
pull down all the houses of a town with the single
design of rebuilding them differently, and thereby
rendering the streets more handsome ; but it often
happens that a private individual takes down his
own with the view of erecting it anew, and that
people are even sometimes constrained to this when
their houses are in danger of falling from age, or
when the foundations are insecure. With this
before me by way of example, I was persuaded
that it would indeed be preposterous for a private
individual to think of reforming a state by funda-

H DESCARTES.

mentally changing it throughout, and overturning it
in order to set it up amended; and the same I
thought was true of any similar project for reform
ing the body of the Sciences, or the order of teach
ing them established in the Schools : but as for the
opinions which up to that time I had embraced, I
thought that I could not do better than resolve at
once to sweep them wholly away, that I might after
wards be in a position to admit either others more .
correct, or even perhaps the same when they had
undergone the scrutiny of Reason. I firmly
believed that in this way I should much better sue-,
ceed in the conduct of my life, than if I built only
upon old foundations, and leant upon principles
which, in my youth, I had taken upon trust. For
although I recognised various difficulties in this
undertaking, these were not, however, without
remedy, nor once to be compared with such as
attend the slightest reformation in public affairs.
Large bodies, if once overthrown, are with great
difficulty set up again, or even kept erect when
once seriously shaken, and the fall of such is always
disastrous. Then if there are any imperfections in
the constitutions of states, (and that many such
exist the diversity of constitutions is alone sufficient
to assure us,) custom has without doubt materially
smoothed their inconveniences, and has even man
aged to steer altogether clear of, or insensibly cor
rected a number which sagacity could not have
provided against with equal effect ; and, in fine, the
defects are almost always more tolerable than the
change necessary for their removal- in the same

DISCOURSE ON METHOD. 15

manner that highways which wind among moun
tains, by being much frequented, become gradually
so smooth and commodious, that it is much better to
follow them than to seek a straighter path by climb
ing over the tops of rocks and descending to the
bottoms of precipices.

-ty Hence it is that I cannot in any degree approve
of those restless and busy meddlers who, called
neither by birth nor fortune to take part in the
management of public affairs, are yet always pro
jecting reforms; and if I thought that this Tract
contained aught which might justify the suspicion
that I was a victim of such folly, I would by no
means permit its publication. I have never con
templated anything higher than the reformation of
my own opinions, and basing them on a foundation
wholly my own. And although my own satisfac
tion with my work has led me to present here a
draft of it, I do not by any means therefore recom
mend to every one else to make a similar attempt.
Those whom God has endowed with a larger meas
ure of genius will entertain, perhaps, designs still
more exalted ; but for the many I am much afraid
lest even the present undertaking be more than
they can safely venture to imitate. The single
design to strip one's self of all past beliefs is one
that ought not to be taken by every one. The
majority of men ^^ is_composed _pf__t^a_classesr for
^neither"of which would .. this be at all a befitting
resolution: in the first place, of those who with
more than a due confidence in their own powers, are
precipitate in their jsdgmentsjmd want the patience

l6 DESCARTES.

requisite for orderly and circumspect thinking;
whence it happens, that if men of this class once
take the liberty to doubt of their accustomed opin
ions, and quit the beaten highway, they will never
be able to thread the byeway that would lead them
by a shorter course, and will lose themselves and
continue to wander for life ; in the second place, of
those who, possessed of sufficient sense or modesty
to determine that there are others who excel them
in the power of discriminating between truth and
error, and by whom they may be instructed, ought
ratfier to content themselves with the opinions of
such than trust for more correct to their own
Reason.

For my own part, I should doubtless have belonged
to the latter class, had I received instruction from but
one master, or had I never known the diversities of
opinion that from time immemorial have prevailed
among men of the greatest learning. But I had
become aware, even so early as during my college
life, that no opinion, however absurd and incredible,
can be imagined, which has not been maintained by
some one of the philosophers ; and afterwards in the
course of my travels I remarked that all those whose
opinions are decidedly repugnant to ours are not on
that account barbarians and savages, but on the con
trary that many of these nations make an equally
good, if not a better, use of their Reason than we
do. I took into account also the very different char
acter which a person brought up from infancy in
Yrance or Germany exhibits, from that which, with
the same mind originally, this individual would have

DISCOURSE ON METHOD. 17

possessed had he lived always among the Chinese or
with savages, and the circumstance that in dress
itself the fashion which pleased us ten years ago,
and which may again, perhaps, be received into
favour before ten years have gone, appears to us at
this moment extravagant and ridiculous. I was thus
led to infer that the ground of our opinions is far
more custom and example than any certain knowl
edge. And, finally, although such be the ground of
our opinions, I remarked that a plurality of suffrages
is no guarantee of truth where it is at all of difficult
discovery, as in such cases it is much more likely
that it will be found by one than by many. I
could, however, select from the crowd no one whose
opinions seemed worthy of preference, and thus I
found myself constrained, as it were, to use my own
Reason in the conduct of my life.

But like one walking alone and in the dark, I
resolved to proceed so slowly and with such circum
spection, that if I did not advance far, I would at
least guard against falling. I did not even choose
to dismiss summarily any of the opinions that had
crept into my belief without having been introduced
by Reason, but first of all took sufficient time care
fully to satisfy myself of the general nature of the
task I was setting myself, and ascertain the true
Method by which to arrive at the knowledge of
whatever lay within the compass of my powers.

Among the branches of Philosophy, I had, at an
earlier period, given some attention to Logic, and
among those of the Mathematics to Geometrical
Analysis and Algebra,— three arts or Sciences

l8 DESCARTES.

which ought, as I conceived, to contribute some
thing to my design. But, on examination, I found
that, as for Logic, its syllogisms and the majority of
its other precepts are of avail rather in the com
munication of what we already know, or even as the
Art of Lully, in speaking without judgment of
things of which we are ignorant, than in the investi
gation of the unknown ; and although this Science
contains indeed a number of correct and very excel
lent precepts, there are, nevertheless, so many
others, and these either injurious or superfluous,
mingled with the former, that it is almost quite as
difficult to effect a ' severance of the true from the
false as it is to extract a Diana or a Minerva from a
rough block of marble. Then as to the Analysis of
the ancients and the Algebra of the moderns,
besides that they embrace only matters highly
abstract, and, to appearance, of no use, the former
is so exclusively restricted to the consideration of
figures, that it can exercise the Understanding only
on condition of greatly fatiguing the Imagination;*
and, in the latter, there is so complete a subjection
to certain rules and formulas, that there results an
art full of confusion and obscurity calculated to
embarrass, instead of a science fitted to cultivate the
mind. By these considerations I was induced to
seek some other Method which would comprise the
advantages of the three and be exempt from their
defects. And as a multitude of laws often only
hampers justice, so that a state is best governed

*The imagination must here be taken as equivalent simply to
the Representative Faculty. — Tr.

DISCOURSE ON METHOD. 19

•when, with few laws, these are rigidly administered;
in like manner, instead of the great number of pre
cepts of which Logic is composed, I believed that
the four following would prove perfectly sufficient
for me, provided I took the firm and unwavering
resolution never in a single instance to fail in
observing them.

The first was never to accept anything for true
which I did not clearly know to be snch ; that is to
say, carefully to avoid precipitancy and prejudice,
and to comprise nothing more in my judgment
than what was presented to my mind so clearly and
distinctly as to exclude all ground of doubt.

The seco-ntf, to divide each of the difficulties under
examination into as many parts as possible, and as
might be necessary for its adequate solution.

The third, to conduct my thoughts in such order
that, by commencing with objects the simplest and
easiest to know, I might ascend by little and little,
and, as it were, step by step, to the knowledge of
the more complex; assigning in thought a certain
order even to those objects which in their own
nature do not stand in a relation of antecedence and
sequence.

And the last, in every case to make enumerations
so complete, and reviews so general, that I might

be assured that nothing was omitted. <2xctP<r VW *^s

& .4^1.44.

The long chains of simple and easy reasonings by . -i

means of which geometers are accustomed to reach uV
the conclusions of their most difficult demonstra- , ^ \}o\\&'h
tions, had led me to imagine that all things, to the . A
knowledge of which man is competent, are mutually

2O DESCARTES.

. connected in the same way, and that there is noth-
4V ing so far removed from us as to be beyond our
ch, or so hidden that we cannot discover it, pro
vided only we abstain from accepting the false for
the true, and always preserve in our thoughts the
order necessary for the deduction of one truth from
another. And I had little difficulty in determining
the objects with which it was necessary to com
mence, for I was already persuaded that it must be
with the simplest and easiest to know, and, consider
ing that of all those who have hitherto sought truth
in the .Sciences, the mathematicians alone have
been able to find any demonstrations, that is, any
certain and evident reasons, I did not doubt but that
such must have been the rule of their investigations.
3 I resolved to commence, therefore, with the exami
nation of the simplest objects, not anticipating,
however, from this any other advantage than that to
be found in accustoming my mind to the love and
nourishment of truth, and to a distaste for all such
reasonings as were unsound. But I had no inten
tion on that account of attempting to master all the
particular Sciences commonly denominated Mathe
matics: but observing that, however different their
objects, they all agree in considering only the
various relations or proportions subsisting among
those objects, I thought it best for my purpose to
consider these proportions in the most general form
possible, without referring them to any objects in
particular, except such as would most facilitate the
knowledge of them, and without by any means
restricting them to these, that afterwards I might

DISCOURSE ON METHOD. 21

thus be the better able to apply them to every other
class of objects to which they are legitimately
applicable. Perceiving- further, that in order to
understand these relations I should sometimes have
to consider them one by one, and sometimes only to
bear them in mind, or embrace them in the aggre
gate, I thought that, in order the better to consider
them individually, I should view them as subsisting
between straight lines, than which I could find no
objects more simple, or capable of being more dis
tinctly represented to my imagination and senses;
and on the other hand, that in order to retain them
in the memory, or embrace an aggregate of many,
I should express them by certain characters the
briefest possible. In this way I believed that I
could borrow all that was best both in Geometrical
Analysis and in Algebra, and correct all the defects
of the one by help of the other.

And, in point of fact, the accurate observance of
these few precepts gave me, I take the liberty of
saying, such ease in unravelling all the questions
embraced in these two sciences, that in the two or
three months I devoted to their examination, not
only did I reach solutions of questions I had for
merly deemed exceedingly difficult, but even as
regards questions of the solution of which I con
tinued ignorant, I was enabled, as it appeared to
me, to determine the means whereby, and the extent
to which, a solution was possible; results attribu
table to the circumstance that I commenced with the
simplest and most general truths, and that thus
each truth discovered was a rule available in the dis-

22 DESCARTES.

covery of subsequent ones. Nor in this perhaps
shall I appear too vain, if it be considered that, as
the truth on any particular point is one, whoever
apprehends the truth, knows all that on that point
can be known. The child, for example, who has
been instructed in the elements of Arithmetic, and
has made a particular addition, according to rule,
may be assured that he has found, with respect to
the sum of the numbers before him, all that in this
instance is within the reach of human genius. Now,
in conclusion, the Method which teaches adherence
to the true order, and an exact enumeration of all
the conditions of the thing sought, includes all that
gives certitude to the rules of Arithmetic.

But the chief ground of my satisfaction with this
Method, was the assurance I had of thereby exercis
ing my reason in all matters, if not with absolute
perfection, at least with the greatest attainable by
me: besides, I was conscious that by its use my
mind was becoming gradually habituated to clearer
and more distinct conceptions of its objects; and I
hoped, also, from not having restricted this Method
to any particular matter, to apply it to the diffi
culties of the other Sciences, with not less success
than to those of Algebra. I should not, however,
on this account have ventured at once on the exam
ination of all the difficulties of the Sciences which
presented themselves to me, for this would have
been contrary to the order prescribed in the
Method, but observing that the knowledge of such
is dependent on principles borrowed from Philos
ophy, in which I found nothing certain, I thought it

DISCOURSE ON METHOD. 23

necessary first of all to endeavour to establish its
principles. And because I observed, besides, that
an inquiry of this kind was of all others of the great
est moment, and one in which precipitancy and
anticipation in judgment were most to be dreaded, I
thought that I ought not to approach it till I had
reached a more mature age, (being at that time but
twenty- three,) and had first of all employed much of
my time in preparation for the work, as well by
eradicating from my mind all the erroneous opinions
I had up to that moment accepted, as by amassing
variety of experience to afford materials for my
reasonings, and by continually exercising myself in
my chosen Method with a view to increased skill in
its application.

PART III.

AND, finally, as it is not enough, before commenc
ing to rebuild the house in which we live, that it be
pulled down, and materials and builders provided,
or that we engage in the work ourselves, according
to a plan which we have beforehand carefully
drawn out, but as it is likewise necessary that we be
furnished with some other house in which we may
live commodiously during the operations, so that I
might not remain irresolute in my actions, while
my Reason compelled me to suspend my judgment,
and that I might not be prevented from living
thenceforward in the greatest possible felicity, I
formed a provisory code of Morals, composed of
three or four maxims, with which I am desirous to
make you acquainted.

The first was to obey the laws and customs of my
country, adhering firmly to the Faith in which, by
the grace of God, I had been educated from my
childhood, and regulating my conduct in every
other matter according to the most moderate opin
ions, and the farthest removed from extremes,
which should happen to be adopted in practice with
general consent of the most judicious of those
among whom I might be living. For, as I had from
that time begun to hold my own opinions for nought
because I wished to subject them all to examina-

24

DISCOURSE ON METHOD. 25

tion, I was convinced that I could not do better
than follow in the meantime the opinions of the
most judicious; and although there are some per
haps among the Persians and Chinese as judicious*
as among ourselves, expediency seemed to dictate
that I should regulate my practice conformably to
the opinions of those with whom I should have to
live ; and it appeared to me that, in order to ascer
tain the real opinions of such, I ought rather to take
cognizance of what they practised than of what they
said, not only because, in the corruption of our
manners, there are few disposed to speak exactly as
they believe, but also because very many are not
aware of what it is that they really believe; for,
as the act of mind by which a thing is believed is
different from that by which we know that we
believe it, the one act is often found without the
other. Also, amid many opinions held in equal
repute, I chose always the most moderate, as much
for the reason that these are always the most con
venient for practice, and probably the best, (for_aH
excess is generally vicious,) as that, in the event of
my~falling into error, I might be at less distance
from the truth than if, having chosen one of the
extremes, it should turn out to be the other which I
ought to have adopted. And I placed in the class
of extremes especially all promises by which some-
what of our freedom is abridged ; not that I disap
proved of the laws which, to provide against the
instability of men of feeble resolution, when what is
sought to be accomplished is some good, permit
engagements by vows and contracts binding the

26 DESCARTES.

parties to persevere in it, or even, for the security
of commerce, sanction similar engagements where
the purpose sought to be realized is indifferent: but
because I did not find anything on earth which was
wholly superior to change, and because, for myself
in particular, I hoped gradually to perfect my judg
ments, and not to suffer them to deteriorate, 1
would have deemed it a grave sin against good
sense, if, for the reason that I approved of some
thing at a particular time, I therefore bound myself
to hold it for good at a subsequent ^me, when per
haps it had ceased to be so, or I had ceased to
esteem it such.

My second maxim was to be as firm and resolute in
my actions as I was able, and not to adhere less
steadfastly to the most doubtful opinions, when once
adopted, than if they had been highly certain; imi
tating in this the example of travellers who,
when they have lost their way in a forest, ought
not to wander from side to side, far less remain in
one place, but proceed constantly towards the same
side in as straight a line as possible, without chang
ing their direction for slight reasons, although per
haps it might be chance alone which at first
determined the selection; for in. this way, if they do
not exactly reach the point they desire, they will
come at least in the end to some place that will
probably be preferable to the middle of a forest.
In the same way, since in action it frequently hap
pens that no delay is permissible, it is very certain
that, when it is not in our power to determine what
is true, we ought to act according to what is most

DISCOURSE ON METHOD. 2?

probable; 'and even although we should not remark
a greater probability in one opinion than in
another, we ought notwithstanding to choose one or
the other, and afterwards consider it, in so far as it
relates to practice, as no longer dubious, but mani
festly true and certain, since the reason by which
our choice has been determined is itself possessed of
these qualities. This principle was sufficient thence
forward to rid me of all those repentings and pangs
of remorse that usually disturb the consciences of
such feeble and uncertain minds as, destitute of any
clear and determinate principle of choice, allow
themselves one day to adopt a course of action as the
best, which they abandon the next, as the opposite.
My third maxim was to endeavour always to con
quer myself rather than fortune, and change my
desires rather than the order of the world, and in
general, accustom myself to the persuasion that,
except our own thoughts, there is nothing absolutely
in our power; so that when we have done our best
in respect of things external to us, ail wherein we
fail of success is to be held, as regards us, abso
lutely impossible: and this single principle seemed
to me sufficient to prevent me from desiring for the
future anything which I could not obtain, and thus
render me contented; for since our will naturally
seeks those objects alone which the understanding
represents as in some way possible of attainment, it
is plain, that if we consider all external goods as
equally beyond our power, we shall no more regret
the absence of such goods as seem due to our birth,
when deprived of them without any fault of ours,

28 DESCARTES.

than our not possessing- the kingdoms of China or
Mexico; and thus making, so to speak, a virtue of
necessity, we shall no more desire health in disease,
or freedom in imprisonment, than we now do bodies
incorruptible as diamonds, or the wings of birds to
fly with. But I confess there is need of prolonged
discipline and frequently repeated meditation to
accustom the mind to view all objects in this light ;
and I believe that in this chiefly consisted the
secret of the power of such philosophers as in
former times were enabled to rise superior to the
influence of fortune, and, amid suffering and pov
erty, enjoy a happiness which their gods might have
envied. For, occupied incessantly with the con
sideration of the limits prescribed to their power by
nature, they became so entirely convinced that
nothing was at their disposal except their own
thoughts, that this conviction was of itself sufficient
to prevent their entertaining any desire of other
objects; and over their thoughts they acquired a
sway so absolute, that they had some ground on this
account for esteeming themselves more rich and
more powerful, more free and more happy, than
other men who, whatever be the favours heaped on
them by nature and fortune, if destitute of this
philosophy, can never command the realization of
all their desires.

In fine, to conclude this code of Morals, I thought
of reviewing the different occupations of men in this
life, with the view of making choice of the best.
And, without wishing to offer any remarks on the
employments of others, I may state that it was my

DISCOURSE ON METHOD. 29

conviction that I could not do better than continue
in that in which I was engaged, viz., in devoting
my whole life to the culture of my Reason, and in
making the greatest progress I was able in the
knowledge of truth, on the principles of the Method
which I had prescribed to myself. This Method,
from the time I had begun to apply it, had been to
me the source of satisfaction so intense as to lead
me to believe that more perfect or more innocent
could not be enjoyed in this life ; and as by its means
I daily discovered truths that appeared to me of
some importance, and of which other men were
generally ignorant, the gratification thence arising
so occupied my mind that I was wholly indifferent
to every other object. Besides, the three preceding
maxims were founded singly on the design of con
tinuing the work of self-instruction. For since God
has endowed each of us with some Light of Reason
by which to distinguish truth from error, I could not
have believed that I ought for a single moment to
rest satisfied with the opinions of another, unless I
had resolved to exercise my own judgment in
examining these whenever I should be duly quali
fied for the task. Nor could I have proceeded on
such opinions without scruple, had I supposed that I
should thereby forfeit any advantage for attaining
still more accurate, should such exist. And, in fine,
I could not have restrained my desires, nor
remained satisfied, had I not followed a path in
which I thought myself certain of attaining all the
knowledge to the acquisition of which I was compe
tent, as well as the largest amount of what is truly

30 DESCARTES.

good which I could ever hope to secure. Inasmuch
as we neither seek nor shun any object except in so
far as our understanding represents it as good or
bad, all that is necessary to right action is right
judgment, and to the best action the most correct
judgment, — that is, to the acquisition of all the
virtues with all else that is truly valuable and within
our reach ; and the assurance of such an acquisition
cannot fail to render us contented.

Having thus provided myself with these maxims,
and having placed them in reserve along with the
truths of Faith, which have ever occupied the first
place in my belief, I came to the conclusion that I
might with freedom set about ridding myself of
what remained of my opinions. And, inasmuch as I
hoped to be better able successfully to accomplish
this work by holding intercourse with mankind,
than by remaining longer shut \\p in the retirement
where these thoughts had occurred to me, I betook
me again to travelling before the winter was well
ended. And, during the nine subsequent years, %
did nothing but roam from one place to another,
desirous of being a spectator rather than an actor in
the plays exhibited on the theatre of the world ;
and, as I made it my business in each matter to
reflect particularly upon what might fairly be
doubted and prove a source of error, I gradually
rooted out from my mind all the errors which had
hitherto crept into it. Not that in this I imitated
the Sceptics who doubt only that they may doubt,
and seek nothing beyond uncertainty itself ; for, on
the contrary, my design was singly to find ground

DISCOURSE ON METHOD. 3 1

of assurance, and cast aside the loose earth and
sand, that I might reach the rock or the clay. In
this, as appears to me, I was successful enough ; for,
since I endeavoured to discover the falsehood or
incertitude of the propositions I examined, not by
feeble conjectures, but by clear and certain reason
ings, I met with nothing so doubtful as not to yield
some conclusion of adequate certainty, although this
were merely the inference, that the matter in ques
tion contained nothing certain. And, just as in
pulling down an old house, we usually reserve the
ruins to contribute towards the erection, so, in
destroying such of my opinions as I judged to be ill-
founded, I ma4e a variety of observations and ac
quired an amount of experience of which I availed
myself in the establishment of more certain. And
further, I continued to exercise myself in the Method
I have prescribed ; for, besides taking care in general
to conduct all my thoughts according to its rules, I
reserved some hours from time to time which I
expressly devoted to the employment of the Method,
in the solution of Mathematical difficulties, or even
in the solution likewise of some questions belonging
to other Sciences, but which, by my having
detached them from such principles of these Sci
ences as were of inadequate certainty, were rendered
almost Mathematical: the truth of this will be
manifest from the numerous examples contained in
this volume.* And thus, without in appearance
living otherwise than those who, with no other

*The Discourse on Method was originally published along
with the Dioptrics, the Meteorics, and the Geometry.— Tr.

32 DESCARTES.

occupation than that of spending their lives agree
ably and innocently, study to Fever pleasure from
vice, and who, that they may enjoy their leisure
without ennui, have recourse to such pursuits as are
honourable, I was nevertheless prosecuting my
design, and making greater progress in the knowl
edge of truth, than I might, perhaps, have made
had I been engaged in the perusal of books merely,
or in holding converse with men of letters.

These nine years passed away, however, before I
had come to any determinate judgment respecting
the difficulties which form matter of dispute among
the learned, or had commenced to seek the prin
ciples of any Philosophy more certain than the
vulgar. And the examples of many men of the
highest genius, who had, in former times, engaged
in this inquiry, but, as appeared to me, without suc
cess, led me to imagine it to be a work of so much
difficulty, that I would not perhaps have ventured
on it so soon had I not heard it currently rumoured
that I had already completed the inquiry. I know
not what were the grounds of this opinion;
and, if my conversation contributed in any measure
to its rise, this must have happened rather from my
having confessed my ignorance with greater free
dom than those are accustomed to do who have
studied a little, and expounded, perhaps, the reasons
that led me to doubt of many of those things that by
others are esteemed certain, than from my having
boasted of any system of Philosophy. But, as I am
of a disposition that makes me unwilling to be
esteemed different from what I really am, I thought

DISCOURSE ON METHOD. 33

it necessary to endeavour by all means to render
myself worthy of the reputation accorded to me; and
it is now exactly eight years since this desire con
strained me to remove from all those places where
interruption from any of my acquaintances was pos
sible, and betake myself to this country,* in which
the long duration of the war has led to the establish
ment of such discipline, that the armies maintained
seem to be of use only in enabling the inhabitants
to enjoy more securely the blessings of peace; and
where, in the midst of a great crowd actively
engaged in business, and more careful of their own
affairs than curious about those of others, I have
been enabled to live without being deprived of any
of the conveniences to be had in the most populous
cities, and yet as solitary and as retired as in the
midst of the most remote deserts.

* Holland; to which country he withdrew in 1629.— TV.

PART IV.

I AM in doubt as to the propriety of making mv
first meditations in the place above mentioned
matter of discourse; for these are so metaphysical,
and so uncommon, as not, perhaps, to be acceptable
to every one. And yet, that it may be determined
whether the foundations that I have laid are
sufficiently secure, I find myself in a measure con
strained to advert to them. I had long before
remarked that, in relation to practice, it is some
times necessary to adopt, as if above doubt, opin
ions which we discern to be highly uncertain, as has
been already said; but as I then desired to give my
attention solely to the search after truth, I thought
that a procedure exactly the opposite was called for,
and that I ought to reject as absolutely false all
opinions in regard to which I could suppose the
least ground for doubt, in order to ascertain
whether after that there remained aught in my
belief that was wholly indubitable. Accordingly,
seeing that our senses sometimes deceive us, I was
willing to suppose that there existed nothing really
such as they presented to us; and because some
men err in reasoning, and fall into paralogisms,
even on the simplest matters of Geometry, I, con
vinced that I was as open to error as any other,

34

DISCOURSE ON METHOD. 35

rejected as false all the reasonings I had hitherto
taken for demonstrations; and finally, when I con
sidered that the very same thoughts (presentations)
which we experience when awake may also be
experienced when we are asleep, while there is at
that time not one of them true, I supposed that all
the objects (presentations) that had ever entered
into my mind when awake, had in them no more
truth than the illusions of my dreams. But imme
diately upon this I observed that, whilst I thus
wished to think that all was false, it was absolutely
necessary that I, who thus thought, should be some-
what; and as I observed that this truth, / think,
hence I am, was so certain and of such evidence, that
no ground of doubt, however extravagant, could be
alleged by the Sceptics capable of shaking it, I con
cluded that I might, without scruple, accept it as the
first principle of the Philosophy of which I was in
search.

In the next place, I attentively examined what I
was, and as I observed that I could suppose that I
had no body, and that there was no world nor any
place in which I might be; but that I could not
therefore suppose that I was not ; and that, on the
contrary, from the very circumstance that I thought
to doubt of the truth of other things, it most clearly
and certainly followed that I was; while, on the
other hand, if I had only ceased to think, although
all the other objects which I had ever imagined had
been in reality existent, I would have had no reason
to believe that I existed; I thence concluded that I
was a substance whose whole essence or nature

36 DESCARTES

consists only in thinking-, and which, that it may
exist, has need of no place, nor is dependent on any
material thing; so that "I," that is to say, .the jpincl
by which I am what, Lam. is_ wholly ^distinct frgm
me body, and is even more easily known than the
latter, and is such, that although the latter were not,
it would still continue to be all that it is.

After this I inquired in general into what is essen
tial to the truth and certainty of a proposition ; for
since I had discovered one which I knew to be true,
I thought that I must likewise be able to discover
the ground of this certiiude. And as I observed
that in the words / think, hence I am, there is noth
ing at all which gives me assurance of their truth
beyond this, that I see very clearly that in order to
think it is necessary to exist, I concluded that I
might take, as a general rule, the principle, that all
the things which we very clearly and distinctly con
ceive are true, only observing, however, that there is
some difficulty in rightly determining the objects
which we distinctly conceive.

In the next place, from reflecting on the circum
stance that I doubted, and that consequently my
being was not wholly perfect, (for I clearly saw that
it was a greater perfection to know than to doubt,)
I was led to inquire whence I had learned to think
of something more perfect than myself; and I
clearly recognised that I must hold this notion from
some Nature which in reality was more perfect. As
for the thoughts of many other objects external to
me, as of the sky, the earth, light, heat, and a thou
sand more, I was less at a loss to know whence these

DISCOURSE ON METHOD. 37

came ; for since I remarked in them nothing which
seemed to render them superior to myself, I could
believe that, if these were true, they were depend
encies on my own nature, in so far as it possessed a
certain perfection, and, if they were false, that I
held them from nothing, that is to say, that they
were in me because of a certain imperfection of my
nature. But this could not be the case with the idea
of a Nature more perfect than myself; for to receive
it from nothing was a thing manifestly impossible ;
and, because it is not less repugnant that the more
perfect should be an effect of, and dependence on
the less perfect, than that something should proceed
from nothing, it was equally impossible that I could
hold it from myself: accordingly, it but remained
that it had been placed in me by a Nature which
was in reality more perfect than mine, and which
even possessed within itself all the perfections of
which I could form any idea; that is to say, in a
single word, which was God. And to this I added
that, since I knew some perfections which I did not
possess, I was not the only being in existence,
(I will here, with your permission, freely use the
terms of the schools) ; but, on the contrary, that
there was of necessity some other more perfect
Being upon whom I was dependent, and from whom
I had received all that I possessed; for if I had
existed alone, and independently of every other
being, so as to have had from myself all the perfec
t-ion, however little, which I actually possessed, I
should have been able, for the same reason, to have
had from myself the whole remainder of perfection,

DESCARTES.

38

of the want of which I was conscious, and thus could
of myself have become infinite, eternal, immutable,
omniscient, all-powerful, and, in fine, have possessed
all the perfections which I could recognise in God.
For in order to know the nature of God, (whose
existence has been established by the preceding
reasonings,) as far as my own nature permitted, I
had only to consider in reference to all the proper
ties of which I found in my mind some idea,
whether their possession was a mark of perfection;
and I was assured that no one which indicated any
imperfection was in him, and that none of the rest
was wanting. ' Thus I perceived that doubt, incon
stancy, sadness, and such like, could not be found
in God, since I myself would have been happy to be
free from them. Besides, I had ideas of many
sensible and corporeal things; for although I might
suppose that I was dreaming, and that all which I
saw or imagined was false, I could not, neverthe
less, deny that the ideas were in reality in my
thoughts. But, because I had already very clearly
recognised in myself that the intelligent nature is.
distinct from the corporeal, and as I observed that
' all composition is an evidence of dependency, and
that a state of dependency is manifestly a state of
imperfection, I therefore determined that it could
not be a perfection in God to be compounded of
these two natures, and that consequently he was not
so compounded; but that if there were anybodies
in the world, or even any intelligences, or other
natures that were not wholly perfect, their exist
ence depended on his power in such a way that

DISCOURSE ON METHOD. 39

they could not subsist without him for a single
moment.

I was disposed straightway to search for other
truths; and when 1 had represented to myself the
object of the geometers, which I conceived to be a
continuous body, or a space indefinitely extended
in length, breadth, and height or depth, divisible
into divers parts which admit of different figures
and sizes, and of being moved or transposed in all
manner of ways, (for all this the geometers suppose
to be in the object they contemplated I went over
some of their simplest demonstrations. And, in the
first place, I observed, that the great certitude which
by common consent is accorded to these demonstra
tions, is founded solely upon this, that they are
clearly conceived in accordance with the rules I
have already laid down. In the next place, I per
ceived that there was nothing at all in these demon
strations which could assure me of the existence of
their object: thus, for example, supposing a tri
angle to be given, I distinctly perceived that its
three angles were necessarily equal to two right
angles, but I did not on that account perceive any
thing which could assure me that any triangle
existed: while, on the contrary, recurring to the
examination of the idea of a Perfect Being, I found
that the existence of the Being was comprised in the
idea in the same way that the equality of its three
angles to two right angles is comprised in the idea
of a triangle, or as in the idea of a sphere, the
equidistance of all points on its surface from the
centre, or even still more clearly; and that conse-

40 DESCARTES.

quently it is at least as certain that God, who is this
Perfect Being, is, or exists, as any. demonstration of
Geometry can be.

But the reason which leads many to persuade
themselves that there is a difficulty in knowing this
truth, and even also in knowing what their mind
really is, is that they never raise their thoughts
above sensible objects, and are so accustomed to
consider nothing except by way of imagination,
which is a mode of thinking limited to material
objects, that all that is not imaginable seems to
them not intelligible. The truth of this is suffi
ciently manifest from the single circumstance, that
the philosophers of the Schools accept as a maxim
that there is nothing in the Understanding which
was not previously in the Senses, in which however
it is certain that the ideas of God and of the soul
have never been; and it appears to me that they
who make use of their imagination to comprehend
these ideas do exactly the same thing as if, in order
to hear sounds or smell odours, they strove to avail
themselves of their eyes; unless indeed'that there is
this difference, that the sense of sight does not
afford us an inferior assurance to those of smell or
hearing; in place of which, neither our imagination
nor our senses can give us assurance of anything
unless our Understanding intervene.

Finally, if there be still persons who are not suffi
ciently persuaded of the existence of God and of the
soul, by the reasons I have adduced, I am desirous
that they should know that all the other proposi
tions, of the truth of which they deem themselves

DISCOURSE ON METHOD. 41

perhaps more assured, as that we have a body, and
that there exist stars and an earth, and such like,
are less certain; for, although we have a moral
assurance of these things, which is so strong that
there is an appearance of extravagance in doubting
of their existence, yet at the same time no one,
unless his intellect is impaired, can deny, when the
question relates to a metaphysical certitude, that
there is sufficient reason to exclude entire assur
ance, in the observation that when asleep we can
in the same way imagine ourselves possessed of
another body and that we see other stars and
another earth, when there is nothing of the kind.
For how do we know that the thoughts which occur
in dreaming are false rather than those other which
we experience when awake, since the former are
often not less vivid and distinct than the latter?
And though men of the highest genius study this
question as long as they please, I do not believe that
they will be able to give any reason which can be
sufficient to remove this doubt, unless they presup
pose the existence of God. For, in the first place,
"even the principle which I have already taken as a
rule, viz. , that all the things which we clearly and
distinctly conceive are true, is certain only because
God is or exists, and because he is a Perfect Being,
and because all that we possess is derived from
him: whence it follows that our ideas or notions,
which to the extent of their clearness and distinct
ness are real, and proceed from God, must to that
extent be true. Accordingly, whereas we not
unfrequently have ideas or notions in which some

42 DESCARTES.

falsity is contained, this can only be the case with
such as are to some extent confused and obscure,
and in this proceed from nothing, (participate of
negation,) that is, exist in us thus confused because
we are not wholly perfect. And it is evident that it
is not less repugnant that falsity or imperfection, in
so far as it is imperfection, should proceed from
God, than that truth or perfection should proceed
from nothing. But if we did not know that all
which we possess of real and true proceeds from a
Perfect and Infinite Being, however clear and dis
tinct our ideas might be, we should have no grouncV
on that account for the assurance that they pos-
sessed the perfection of being true.

But after the knowledge of God and of the soul
has rendered us certain of this rule, we can easily
understand that the truth of the thoughts we experi
ence when awake, ought not in the slightest degree
to be called in question on account of the illusions
of our dreams. For if it happened that an indi
vidual, even when asleep, had some very distinct
idea, as, for example, if a geometer should discover
some new demonstration, the circumstance of his
being asleep would not militate against its truth;
and as for the most ordinary error of our dreams,
which consists in their representing various ob
jects in the same way as our external senses,
tjiis is not prejudicial, since Jt leads us very prop
erly to suspect the truth of the ideas of sense*
for we are not unfrequently deceived in the same
manner when awake; as when persons in the
jaundice see all objects yellow, or when the stars or

DISCOURSE ON METHOD.

43

bodies at a great distance appear to us much smaller
than they are. For, in fine, whether awake or
asleep, we ought never to allow ourselves to be per
suaded of the truth of anything unless on the evi
dence of our Reason. And it must be noted that I
say of our Reason, and not of our imagination or of
our senses: thus, for example, although we very
clearly see the sun, we ought not therefore to
determine that it is only of the size which our sense
of sight presents ; and we may very distinctly imag
ine the head of a lion joined to the body of a goat,
without being therefore shut up to the conclusion
that a chinuera exists; for it is not a dictate of
Reason that what we thus see or imagine is in reality
existent ; but it plainly tells us that all our ideas or
notions contain in them some truth ; for otherwise it
could not be that God, who is wholly perfect and
veracious, should have placed them in us. And
because our reasonings are never so clear or so com
plete during sleep as when we are awake, although
sometimes the acts of our imagination are then as
lively and distinct, if not more so than in our wak
ing moments, Reason further dictates that, since all
our thoughts cannot be true because of our partial
imperfection, those possessing truth must infallibly
be found in the experience of our waking moments
rather than in that of our dreams.

PART V.

I WOULD here willingly have proceeded to exhibit
the whole chain of truths which I deduced from
these primary; but as with a view to this it would
have been necessary now to treat of many questions
in dispute among the learned, with whom I do not
wish to be embroiled, I believe that it will be better
for me to refrain from this exposition, and only
mention in general what these truths are, that the
more judicious may be able to determine whether a
more special account of them would conduce to the
public advantage. I have ever remained firm in my
original resolution to suppose no other principle than
that of which I have recently availed myself in
demonstrating the existence of God and of the soul,
and to accept as true nothing that did not appear to
me more clear and certain than the demonstrations
of the geometers had formerly appeared ; and yet I
venture to state that not only have I found means to
satisfy myself in a short time on all the principal
difficulties which are usually treated of in Philos
ophy, but I have also observed certain laws estab
lished in nature by God in such a manner, and of
which he has impressed on our minds such notions,
that after we have reflected sufficiently upon these,
we cannot doubt that they are accurately observed

44

DISCOURSE ON METHOD.

45

in all that exists or takes place in the world: and
farther, by considering the concatenation of these
laws, it appears to me that I have discovered many
truths more useful and more important than all I
had before learned, or even had expected to learn.

But because I have essayed to expound the chief
of these discoveries in a Treatise which certain con
siderations prevent me from publishing, I cannot
make the results known more conveniently than by
here giving a summary of the contents of this
Treatise. It was my design to comprise in it all
that, before I set myself to write it, I thought I
knew of the nature of material objects. But like
the painters who, finding themselves unable to rep
resent equally well on a plain surface all the differ
ent faces of a solid body, select one of the chief, on
which alone they make the light fall, and throwing
the rest into the shade, allow them to appear only in
so far as they can be seen while looking at the prin
cipal one ; so, fearing lest I should not be able to
comprise in my discourse all that was in my mind, I
resolved to expound singly, though at considerable
length, my opinions regarding light; then to take
the opportunity of adding something on the sun and
the fixed stars, since light almost wholly proceeds
from them ; on the heavens, since they transmit it ;
on the planets, comets, and earth, since they reflect
it; and particularly on all the bodies that are upon
the earth, since they are either coloured, or trans
parent, or luminous; and finally on man, since he is
the spectator of these objects. Further, to enable
me to cast this variety of subjects somewhat into the

46 DESCARTES.

shade, and to express my judgment regarding them
with greater freedom, without being necessitated to
adopt or refute the opinions of the learned, I
resolved to leave all the people here to their disputes,
and to speak only of what would happen in a new
world, if God were now to create somewhere in the
imaginary spaces matter sufficient to compose one,
and were to agitate variously and confusedly the
different parts of this matter, so that there resulted
a chaos as disordered as the poets ever feigned, and
after that did nothing more than lend his ordinary
concurrence to nature, and allow her to act in
accordance with the laws which he had established.
On this supposition, I, in the first place, described
this matter, and essayed to represent it in such a
manner that to my mind there can bo nothing
clearer and more intelligible, except what has been
recently said regarding God and the soul; for I even
expressly supposed that it possessed none of those
forms or qualities which are so debated in the
Schools, nor in general anything the knowledge of
which is not so natural to our minds that no one can
so much as imagine himself ignorant of it. Besides,
I have pointed out what are the laws of nature;
and, with no other principle upon which to found
my reasonings except the infinite perfection of God,
I endeavoured to demonstrate all those about which
there could be any room for doubt, and to prove that
they are such, that even if God had created more
worlds, there could have been none in which these
laws were not observed. Thereafter, I showed how
the greatest part of the matter of this chaos must, in

DISCOURSE ON METHOD. 47

accordance with these laws, dispose and arrange
itself in such a way as to present the appearance of
heavens; how in the meantime some of its parts
must compose an earth and some planets and comets,
and others a sun and fixed stars. And, making a
digression at this stage on the subject of light, I
expounded at considerable length what the nature
of that light must be which is found in the sun and
the stars, and how thence fn an instant of time it
traverses the immense spaces of the heavens, and
how from the planets and comets it is reflected
towards the earth. To this I likewise added much
respecting the substance, the situation, the motions,
and all the different qualities of these heavens and
stars; so that I thought I had said enough respect
ing them to show that there is nothing observable in
the heavens or stars of our system that must not, or
at least may not, appear precisely alike in those of
the system which I described. I came next to
speak of the earth in particular, and to show how,
even though I had expressly supposed that God had
given no weight to the matter of which it is com
posed, this should not prevent all its parts from
tending exactly to its centre ; how with water and
air on its surface, the disposition of the heavens and
heavenly bodies, more especially of the moon, must
cause a flow and ebb, like in all its circumstances to
that observed in our seas, as also a certain current
both of water and air from east to west, such as is
likewise observed between the tropics; how the
mountains, seas, fountains, and rivers might natur
ally be formed in it, and the metals produced in the

48 DESCARTES.

mines, and the plants grow in the fields; and in
general, how all the bodies which are commonly
denominated mixed or composite might be gener
ated: and, among other things in the discoveries
alluded to, inasmuch as besides the stars, I knew
nothing except fire which produces light, I spared
no pains to set forth all that pertains to its nature,
— the manner of its production and support, and to
explain how heat is sometimes found without light,
and light without heat; to show how it can induce
various colours upon different bodies and other
diverse qualities; how it Teduces some to a liquid
state and hardens others; how it can consume
almost all bodies, or convert them into ashes and
smoke; and finally, how from these ashes, by the
mere intensity of its action, it forms glass: for as
this transmutation ofwshes into glass appeared to
me as wonderful as any other in nature, I took a
special pleasure in describing it.

I was not, however, disposed, from these circum
stances, to conclude that this world had been created
in the manner I described; for it is much more
likely that God made it at the first such as it was t®
be. ' But this is certain, and an opinion commonly
received among theologians, that the action by
which he now sustains it is the same with that by
which he originally created it ; so that even although
he had from the beginning given it no other form
than that of chaos, provided only he had established
certain laws of nature, and had lent it his concur
rence to enable it to act as it is wont to do, it may
be believed, without discredit to the miracle of crea-

DISCOURSE ON METHOD. 49

tion, that, in this way alone, things purely material
might, in course of time, have become such as we
observe them at present; and their nature is much
more easily conceived when chey are beheld coming
in this manner gradually into existence, than when
they are only considered as produced at once in a
finished and perfect state.

From the description of inanimate bodies and
plants, I passed to animals, and particularly to man.
But since I had not as yet sufficient knowledge to
enable me to treat of these in the same manner as of
the rest, that is to say, by deducing effects from
their causes, and by showing from what elements
and in what manner Nature must produce them, I
remained satisfied with the supposition that God
formed the body of man wholly like to one of ours,
as well in the external shape of the members as in
the internal conformation of the organs, of the same
matter with that I had described, and at first placed
in it no Rational Soul, nor any other principle, in
room of the Vegetative or Sensitive Soul, beyond
kindling in the heart one of those fires without light,
such as I had already described, and which I
thought was not different from the heat in hay that
has been heaped together before it is dry, or that
which causes fermentation in new wines before they
are run clear of the fruit. For, when I examined
the kind of functions which might, as consequences
of this supposition, exist in this body, I found pre
cisely all those which may exist in us independently
of all power of thinking, and consequently without
being in anv measure owing to the soul ; in other

L

50 DESCARTES.

words, to that part of us which is distinct from the
body, and of which it has been said above that the
nature distinctively consists in thinking, — functions
in which the animals void of Reason may be said
wholly to resemble us; but among which I could
not discover any of those that, as dependent on
thought alone, belong to us as men, while, on the
other hand, I did afterwards discover these as soon
as I supposed God to have created a Rational Soul,
and to have annexed it to this body in a particular
manner which I described.

But, in order to show how I there handled this
matter, I mean here to give the explication of the
motion of the heart and arteries, which, as the first
and most general motion observed in animals, will
afford the means of readily determining what should
be thought of all the rest. And that there may be
less difficulty in understanding what I am about to
say on this subject, I advise those who are not versed
in Anatomy, before they commence the perusal of
these observations, to take the trouble of getting
dissected in their presence the heart of some large
animal possessed of lungs, (for this is throughout
sufficiently like the human,) and to have shewn to
them its two ventricles or cavities: in the first place,
that in the right side, with which correspond two
very ample tubes, viz., the hollow vein, (vena cava,)
which is the principal receptacle of the blood, and
the trunk of the tree, as it were, of which all the
other veins in the body are branches; and the
arterial vein, (vena arteriosa^] inappropriately so
denominated, since it is in truth only an artery,

DISCOURSE ON' METHOD. 51

which, taking its rise in the heart, is divided, after
passing out from it, into many branches which pres
ently disperse themselves all over the lungs; in the
second place, the cavity in the left side, with which
correspond in the same manner two canals in size
equal to or larger than the preceding, viz., the
venous artery, (arteria vcnosa?) likewise inappro
priately thus designated, because it is simply a vein
which comes from the lungs, where it is divided into
many branches, interlaced with those of the arterial
vein, and those of the tube called the windpipe,
through which the air we breathe enters; and the
great artery which, issuing from the heart, sends its
branches all over the body. I should wish also that
such persons were carefully shewn the eleven
pellicles which, like so many small valves, open and
shut the four orifices that are in these two cavities,
viz., three at the entrance of the hollow vein, where
they are disposed in such a manner as by no means
to prevent the blood which it contains from flowing
into the right ventricle of the heart, and yet exactly
to prevent its flowing out, three at the entrance to
the arterial vein, which, arranged in a manner
exactly the opposite of the former, readily permit
the blood contained in this cavity to pass into the
lungs, but hinder that contained in the lungs from
returning to this cavity; and, in like manner, two
others at the mouth of the venous artery, which
allow the blood from the lungs to flow into the left
cavity of the heart, but preclude its return; and
three at the mouth of the great artery, which suffer
the blood to flow from the heart, but prevent its

52 DESCARTES.

reflux. Nor do we need to seek any other reason
for the number of these pellicles beyond this that
the orifice of the venous artery being of an oval
shape from the nature of its situation, can be
adequately closed with two, whereas the others
being round are more conveniently closed with
three. Besides, I wish such persons to observe that
the grand artery and the arterial vein are of much
harder and firmer texture than the venous artery
and the hollow vein ; and that the two last expand
before entering the heart, and there form, as it
were, two pouches denominated the auricles of the
heart, which are composed of a substance similar to
that of the heart itself; and that there is always
more warmth in the heart than in any other part of
the body ; and, finally, that this heat is capable of
causing any drop of blood that passes into the
cavities rapidly' to expand and dilate, just as all
liquors do when allowed to fall drop by drop into
a highly heated vessel.

For, after these things, it is not necessary for me
to say anything more with a view to explain the
motion of the heart, except that when its cavities
are not full of blood, into these the blood of neces
sity flows, — from the hollow vein into the right, and
from the venous artery into the left ; because these
two vessels are always full of blood, and their
orifices, which are turned towards the heart, cannot
then be closed. But as soon as two drops of blood
have thus passed, one into each of the cavities, these
drops which cannot but be very large, because the
orifices through which they pass are wide, and the

DISCOURSE ON METHOD. 53

vessels from which they come full of blood, are
immediately rarefied, and dilated by the heat they
meet with. In this way they cause the whole heart
to expand, and at the same time press home and
shut the five small valves that are at the entrances
of the two vessels from which they flow, and thus
prevent any more blood from coming down into the
heart, and becoming more and more rarefied, they
push open the six small valves that are in the
orifices of the other two vessels, through which they
pass out, causing in this way all the branches of the
arterial vein and of the grand artery to expand
almost simultaneously with the heart — which imme
diately thereafter begins to contract, as do also the
arteries, because the blood that has entered them
has cooled, and the six small valves close, and the
five of the hollow vein and of the venous artery
open anew and allow a passage to other two drops
of blood, which cause the heart and the arteries
again to expand as before. And, because the blood
which thus enters into the heart passes through
these two pouches called auricles, it thence happens
that their motion is the contrary of that of the heart,
and that when it expands they contract. But lest
those who are ignorant of the force of mathematical
demonstrations, and who are not accustomed to dis
tinguish true reasons from mere verisimilitudes,
should venture, without examination, to deny what
has been said, I wish it to be considered that the
motion which I have now explained follows as
necessarily from the very arrangement of the parts,
which may be observed in the heart by the eye

54 DESCARTES.

alone, and from the heat which may be felt with the
fingfers, and from the nature of the blood as learned

O 7

from experience, as does the motion of a clock from
the power, the situation, and shape of its counter
weights and wheels.

But if it be asked how it happens that the blood in
the veins, flowing in this way continually into the
heart, is not exhausted, and why the arteries do not
become too full, since all the blood which passes
through the heart flows into them, I need only men
tion in reply what has been written by a physician*
of England, who has the honour of having broken
the ice on this subject, and of having been the first
to teach that there are many small passages at the
extremities of the arteries, through which the blood
received by them from the heart passes into the
small branches of the veins, whence it again returns
to the heart; so that its course amounts precisely to
a perpetual circulation. Of this we have abundant
proof in the ordinary experience of surgeons, who,
by binding the arm with a tie of moderate strait-
ness above the part where they open the vein, cause
the blood to flow more copiously than it would have
done without any ligature ; whereas quite the con
trary would happen were they to bind it below ; that
is, between the hand and the opening, or were to
make the ligature above the opening very tight.
For it is manifest that the tie, moderately strait
ened, while adequate to hinder the blood already in
the arm from returning towards the heart by the
veins, cannot on that account prevent new blood

* Harvey— Lat. Tr.

DISCOURSE -ON METHOD. 55

from coming- forward through the arteries, because
these are situated below the veins, and their cover
ings, from their greater consistency, are more diffi
cult to compress; and also that the blood which
comes from the heart tends to pass through them to
the hand with greater force than it does to return
from the hand to the heart through the veins. And
since the latter current escapes from the arm by the
opening made in one of the veins, there must of
necessity be certain passages below the ligature,
that is, towards the extremities of the arm, through
which it can come thither from the arteries. This
physician likewise abundantly establishes what he
has advanced respecting the motion of the blood,
from the existence of certain pellicles, so disposed
in various places along the course of the veins, in
the manner of small valves, as not to permit the
blood to pass from the middle of the body towards
the extremities, but only to return from the extrem
ities to the heart; and farther, from experience
which shows that all the blood which is in the body
may flow out of it in a very short time through a
single artery that has been cut, even although this
had been closely tied in the immediate neighbour
hood of the heart, and cut between the heart and the
ligature, so as to prevent the supposition that the
blood flowing out of it could come from any other
quarter than the heart.

But there are many other circumstances which
evince that what I have alleged is the true cause of
the motion of the blood: thus, in the first place, the
difference that is observed between the blood which

56 DESCARTES.

flows from the veins, and that from the arteries,
can only arise from this, that being rarefied, and, as
it were, distilled by passing through the heart, it is
thinner, and more vivid, and warmer immediately
after leaving the heart, in other words, when in the
arteries, than it was a short time before passing into
either, in other words, when it was in the veins;
and if attention be given, it will be found that this
difference is very marked only in the neighbourhood
of the heart ; and is not so evident in parts more
remote from it. In the next place, the consistency
of the coats of which the arterial vein and the great
artery are composed, sufficiently shows that the
blood is impelled against them with more force than
against the veins. And why should the left cavity
of the heart and the great artery be wider and
larger than the right cavity and the arterial vein,
were it not that the blood of the venous artery, hav
ing only been in the lungs after it has passed
through the heart, is thinner, and rarefies more
readily, and in a higher degree, than the blood
which proceeds immediately from the hollow vein?
And what can physicians conjecture from feeling
the pulse unless they know that according as the
blood changes its nature it can be rarefied by the
warmth of the heart, in a higher or lower degree,
and more or less quickly than before? And if it be
inquired how this heat is communicated to the other
members, must it not be admitted that this is
effected by means of the blood, which, passing
through the heart, is there heated anew, and thence
diffused over all the body? Whence it happens,

DISCOURSE ON MKTHOD.

57

that if the blood be withdrawn from any part, the
heat is likewise withdrawn by the same means ; and
although the heart were as hot as glowing- iron, it
would not be capable of warming the feet and
hands as at present, unless it continually sent
thither new blood. We likewise perceive from this,
that the true use of respiration is to bring sufficient
fresh air into the lungs, to cause the blood which
flows into them from the right ventricle of the heart,
where it has been rarefied and, as it were, changed
into vapours, to become thick, and to convert it
anew into blood, before it flows into the left
cavity, without which process it would be unfit for
the nourishment of the fire that is there. This
receives confirmation from the circumstance, that it
is observed of animals destitute of lungs that they
have also but one cavity in the heart, and that in
children who cannot use them while in the womb,
there is a hole through which the blood flows from
the hollow vein into the left cavity of the heart, and
a tube through which it passes from the arterial
vein into the grand artery without passing through
the lung. In the next place, how could digestion be
carried on in the stomach unless the heart com
municated heat to it through the arteries, and along
with this certain of the more fluid parts of the
blood, which assist in the dissolution of the food
that has been taken in? Is not also the operation
which converts the juice of food into blood easily
comprehended, when it is considered that it is dis
tilled by passing and repassing through the heart
perhaps more than one or two hundred times in a

58 DESCARTES.

day? And what more need be adduced to explain
nutrition, and the production of the different
humours of the body, beyond saying, that the force
with which the blood, in being rarefied, passes from
the heart towards the extremities of the arteries,
causes certain of its parts to remain in the members
at which they arrive, and there occupy the place of
some others expelled by them ; and that according
to the situation, shape, or smallness of the pores
with which they meet, some rather than others flow
into certain parts, in the same way that some sieves
are observed to act, which, by being variously per
forated, serve to separate different species of grain?
And, in the last place, what above all is here worthy
of observation, is the generation of the animal
spirits, which are like a very subtle wind, or rather
a very pure and vivid flame which, continually
ascending in great abundance from the heart to the
brain, thence penetrates through the nerves into the
muscles, and gives motion to all the members; so
that to account for other parts of the blood which,
as most agitated and penetrating, are the fittest to
compose these spirits, proceeding towards the brain,
it is not necessary to suppose any other cause, than
simply, that the arteries which carry them thither
proceed from the heart in the most direct lines, and
that, according to the rules of Mechanics, which are
the same with those of Nature, Avhen many objects
tend at once to the same point where there is not
sufficient room for all, (as is the case with the parts
of the blood which flow forth from the left cavity of
the heart and tend towards the brain,) the weaker

DISCOURSE ON METHOl). 59

and less agitated parts must necessarily be driven
aside from that point by the stronger which alone in
this way reach it. *•

I had expounded all these matters with sufficient
minuteness in the Treatise which I formerly thought
of publishing. And after these, I had shewn what
must be the fabric of the nerves and muscles of the
human body to give the animal spirits contained in
it the power to move the members, as when we see
heads shortly after they have been struck off still
move and bite the earth, although no longer ani
mated; what changes must take place in the brain
to produce waking, sleep, and dreams, how light,
sounds, odours, tastes, heat, and all the other quali
ties of external objects impress it with different
ideas by means of the senses ; how hunger, thirst,
and the other internal affections can likewise
impress upon it divers ideas; what must be under
stood by the common sense (scnstts conimunis] in
which these ideas are received, by the memory
which retains them, by the fantasy which can
change them in various ways, and out of them com
pose new ideas, and which, by the same means, dis
tributing the animal spirits through the muscles,
can cause the members of such a body to move in as
many different ways, and in a manner as suited,
whether to the objects that are presented to its
senses or to its internal affections, as can take place
in our own case apart from the guidance of the will.
Nor will this appear at all strange to those who are
acquainted with the variety of movements per
formed by the different automata, or moving

6o

DESCARTES.

machines fabricated by human industry, and that
with help of but few pieces compared with the great
multitude of bones, muscles, nerves, arteries, veins,
and other parts that are found in the body of each
animal, i Such persons will look upon this body as a
machine made by the hands of God, which is incom
parably better arranged, and adequate to move
ments more admirable than is any machine of
human invention' And here I specially stayed to
show that, were there such machines exactly
re-sembling in organs and outward form an ape or
any other irrational animal, we could have no
means of knowing that they were in any respect of
a different nature from these animals; but if there
were machines bearing the image of our bodies, and
capable of imitating our actions as far as it is
morally possible, there would still remain two most
certain tests whereby to know that they were not
therefore really men. Of these the first, is that they
could never use words or other signs arranged in
such a manner as is competent to us in order to
declare our thoughts to others: for we may easily
conceive a machine to be so. constructed that it
emits vocables, and even that it emits some corre
spondent to the action upon it of external objects
which cause a change in its organs ; for example, if
touched in a particular place it may demand what
we wish to say to it, if in another it may cry out
that it is hurt, and such like ; but not that it should
arrange them variously so as appositely to reply to
what is said in its presence, as men of the lowest
grade of intellect can do. The second test is, that

DISCOURSE OX METHOD. 6l

although such machines might execute many things
with equal or perhaps greater perfection than any
of us, they would, without doubt, fail in certain
others from which it could be discovered that they
did not act from knowledge, but solely from the
disposition of their organs: for while -Reason is an
universal instrument that is alike available on every
occasion, these organs, on the contrary, need a par
ticular arrangement for each particular action;
whence it must be- morally impossible that there
should exist in any machine a diversity of organs
sufficient to enable it to act in all the occurrences of
life, in the way in which our reason enables us to
act. "~ Again, by means of these two tests we may
likewise know the difference between men and
brutes. For it is highly deserving of remark, that
there are no men so dull and stupid, not even idiots,
as to be incapable of joining together different
words, and thereby constructing a declaration by
which to make their thoughts understood; and that
on the other hand, there is no other animal, however
perfect or happily circumstanced, which can do the
like. Nor does this inability arise from want of
organs: for we observe that magpies and parrots
can utter words like ourselves, and are yet unable to
speak as we do, that is, so as to show that they
understand what they say; in place of which men
born deaf and dumb, and thus not less, but rather
more than the brutes, destitute of the organs which
others use in speaking, are in the habit of spon
taneously inventing certain signs by which they dis
cover their thoughts to those who, being usually in

62 DESCARTES

their company, have leisure to learn their language.
And this proves not only that the brutes have less
Reason than man, but that they have none at all :

* »

for we see that very little is required to enable a
person to speak ; and since a certain inequality of
capacity is observable among animals of the same
species, as well as among men, and since some are
more capable of being instructed than others, it is
incredible that the most perfect ape or parrot of its
species, should not in this be equal to the most
stupid infant of its kind, or at least to one that was
crack-brained, unless the soul of brutes were of a
nature wholly different from ours. And we ought
not to confound speech with the natural movements
which indicate the passions, and can be imitated by
machines as well as manifested by animals; nor
must it be thought with certain of the ancients, that
the brutes speak, although we do not understand
their language. For if such were the case, since
they are endowed with many organs analogous to
ours, they could as easily communicate their
thoughts to us as to their fellows. It is also very
worthy of remark, that, though there are many ani
mals which manifest more industry than we in cer
tain of their actions, the same animals are yet
observed to show none at all in many others : so that
the circumstance that they do better than we does
not prove that they are endowed with mind, for it
would thence follow that they possessed greater
Reason than any of us, and could surpass us in all
things; on the contrary, it rather proves that they
are destitute of Reason, and that it is Nature which

DISCOURSE ON METHOD. 63

acts in them according to the disposition of their
organs: thus it is seen, that a clock composed only
of wheels and weights can number the hours and
measure time more exactly than we with all our
skill.

I had after this described the Reasonable Soul,
and shewn that it could by no means be educed
from the power of matter, as the other things of
which I had spoken, but that it must be expressly
created ; and that it is not sufficient that it be lodged
in the human body exactly like a pilot in a ship,
unless perhaps to move its members, but that it is
necessary for it to be joined and united more closely
to the body, in order to have sensations and appe
tites similar to ours, and thus constitute a real man.
I here entered, in conclusion, upon the subject of
the soul at considerable length, because it is of the
greatest moment: for after the error of those who
deny the existence of God, an error which I think
I have already sufficiently refuted, there is none
that is more powerful in leading feeble minds astray
from the straight path of virtue than the supposi
tion that the soul of the brutes is of the same nature
with our own; and consequently that after this life
we have nothing to hope for or fear, more than flies
and ants; in place of which, when we know how far
they differ we much better comprehend the reasons
which establish that the soul is of a nature wholly inde
pendent of the body, and that consequently it is not
liable to die with the latter; and, finally, because no
other causes are observed capable of destroying it, we
are naturally led thence to judge that it is immortal.

PART VI.

THREE years have now elapsed since I finished the
Treatise containing all these matters; and I was
beginning to revise it, with the view to put it into
the hands of a printer, when I learned that persons
to whom I greatly defer, and whose authority over
my actions is hardly less influential than is my own
Reason over my thoughts, had condemned a certain
doctrine in Physics, published a short time previ
ously by another individual,* to which I will not say
that I adhered, but only that, previously to their
censure, I had observed in it nothing which I could
imagine to be prejudicial either to religion or
to the state, and nothing therefore which would
have prevented me from giving expression to it
in writing, if Reason had persuaded me of its
truth; and this led me to fear lest among my
own doctrines likewise some one might be found
in which I had departed from the truth, notwith
standing the great care I have always taken not to
accord belief to new opinions of which I had not the
most certain demonstrations, and not to give
expression to aught that might tend to the hurt of
any one. This has been sufficient to make me alter
my purpose of publishing them ; for although the
reasons by which I had been induced to take this

* Galileo. — TV.

64

DISCOURSE ON METHOD. 65

resolution were very strong, yet my inclination,
which has always been hostile to writing books,
enabled me immediately to discover other considera-y
tions sufficient to excuse me for not undertaking thev.
task. And these reasons, on one side and the(
other, are such, that not only is it in some measure)
my interest here to state them, but that of the pub
lic, perhaps, to know them.

I have never made much account of what has pro
ceeded from my own mind ; and so long as I gath
ered no other advantage from the Method I employ
beyond satisfying myself on some difficulties
belonging to the speculative sciences, or endeavour
ing to regulate my actions according to the principles
it taught me, I never thought myself bound to
publish anything respecting it. For in what regards
manners, every one is so full of his own wisdom,
that there might be found as many reformers as
heads, if any were allowed to take upon themselves
the task of mending them, except those whom God
has constituted the supreme rulers of his people, or
to whom he has given sufficient grace and zeal to be
prophets; and although my speculations greatly
pleased myself, I believed that others had theirs,
which perhaps pleased them still more. But as soon
as I had acquired some general notions respecting
Physics, and beginning to make trial of them in
various particular difficulties, had observed how far
they can carry us, and how much they differ from
the principles that have been employed up to the
present time, I believed that I could not keep them
concealed without sinning grievously against the

66 DESCARTES.

law by which we are bound to promote, as far as in
us lies, the general good of mankind. For by them
I perceived it to be possible to arrive at knowledge
highly useful in life, and in room of the Speculative
Philosophy usually taught in the Schools, to dis
cover a Practical, by means of which, knowing the
force and action of fire, water, air, the stars, the
heavens, and all the other bodies that surround us,
as distinctly as we know the various crafts of our
artizans, we might also apply them in the same way
to all the uses to which they are adapted, and thus
render ourselves the lords and possessors of nature. '
And this is a result to be desired, not only in order
to the invention of an infinity of arts, by which we
might be enabled to enjoy without any trouble the
fruits of the earth, and all its comforts, but also and
especially for the preservation of health, which is
without doubt, of all the blessings of this life, the
first and fundamental one ; for the mind is so inti
mately dependent upon the condition and relation
of the organs of the body, that if any means can
ever be found to render men wiser and more ingen
ious than hitherto, I believe that it is in Medicine
they must be sought for. It is true that the science
of Medicine, as it now exists, contains few things
whose utility is very remarkable : but without any
wish to depreciate it, I am confident that there is no
one, even among those whose profession it is, who
does not admit that all at present known in it is
almost nothing in comparison of what remains to be
discovered; and that we could free ourselves from
an infinity of maladies of body as well as of mind,

DISCOURSE ON METHOD. 67

and perhaps also even from the debility of age, if
we had sufficiently ample knowledge of their causes,
and of all the remedies provided for us by Nature.
But since I designed to employ my whole life in the
search after so necessary a Science, and since I had
fallen in with a path which seems to me such, that if
any one follow it he must inevitably reach the end
desired, unless he be hindered either by the short
ness of life or the want of experiments, I judged
that there could be no more effectual provision
against these two impediments than if I were faith
fully to communicate to the public all the little I
might myself have found, and incite men of superior
genius to strive to proceed farther, by contributing,
each according to his inclination and ability, to the
experiments which it would be necessary to make,
and also by informing the public of all they might
discover, so that, by the last beginning where those
before them had left off, and thus connecting the
lives and labours of many, we might collectively
proceed much farther than each by himself could do..
I remarked, moreover, with respect to experi
ments, that they become always more necessary the
more one is advanced in knowledge; for, at the
commencement it is better to make use only of what
is spontaneously presented to our senses, and of
which we cannot remain ignorant, provided we
bestow on it any reflection, however slight, than to
concern ourselves about more uncommon and recon
dite phenomena: the reason of which is, that the
more uncommon often only mislead us so long as
the causes of the more ordinary are still unknown;

68 DESCARTES.

and the circumstances upon which they depend are
almost always so special and minute as to be highly
difficult to detect. But in this I have adopted the
following order: first, I have essayed to find in
-* general the principles, or first causes, of all that is or
can be in the world, without taking into considera
tion for this end anything but God himself who has
created it, and without educing them from any
other source than from certain germs of truths
naturally existing in our minds. In the second
place, I examined what were the first and most
ordinary effects that could be deduced from these
causes; and it appears to me that, in this way, I
have found heavens, stars, an earth, and even on
the earth, water, air, fire, minerals, and some other
things of this kind, which of all others are the most
common and simple, and hence the easiest to know.
Afterwards, when I wished to descend to the more
particular, so many diverse objects presented them
selves to me, that I believed it to be impossible for
the human mind to distinguish the forms or species
of bodies that are upon the earth, from an infinity of
others which might have been, if it had pleased God
to place them there, or consequently to apply them
to our use, unless we rise to causes through their
effects, and avail ourselves of many particular
experiments. /Thereupon, turning over in my mind
all the objects that had ever been presented to my
senses, I freely venture to state that I have never
observed any which I could not satisfactorily explain
by the principles I had discovered.' But it is neces
sary also to confess that the power of nature is so

DISCOURSE ON METHOD. 69

ample and vast, and these principles so simple and
general, that I have hardly observed a single par
ticular effect which I cannot at once recognise as
capable of being deduced in many different modes
from the principles, and that my greatest difficulty
usually is to discover in which of these modes the
effect is dependent upon them; for out of this diffi
culty I cannot otherwise extricate myself than by
. again seeking certain experiments, which may be
' such that their result is not the same, if it is in the
• one of these modes that we must explain it, as it
would be if it were to be explained in the other. As
to what remains, I am no win a position to discern, as
I think, with sufficient clearness what course must
be taken to make the majority of those experiments
which may conduce to this end: but I perceive like
wise that they are such and so numerous, that
neither my hands nor my income, though it were a
thousand times larger than it is, would be sufficient
for them all ; so that, according as henceforward I
shall have the means of making more or fewer
experiments, I shall in the same proportion make
greater or less progress in the knowledge of nature.
This was what I had hoped to make known by the
Treatise I had written, and so clearly to exhibit the
advantage that would .thence accrue to the public,
as to induce all who have the common good of man
at heart, that is, all who are virtuous in truth, and
not merely in appearance, or according to opinion,
as well to communicate to me the experiments they
had already made, as to assist me in those that
remain to be made.

70 DESCARTES.

But since that time other reasons have occurred to
me, by which I have been led to change my opinion,
and to think that I ought indeed to go on commit
ting to writing all the results which I deemed of any
moment, as soon as I should have tested their truth,
and to bestow the same care upon them as I would
have done had it been my design to publish them.
This course commended itself to me, as well because
I thus afforded myself more ample inducement to
examine them thoroughly, for doubtless that is
always more narrowly scrutinized which we believe
will be read by many, than that which is written
merely for our private use, (and frequently what
has seemed to me true when I first conceived it, has
appeared false when I have set about committing it
to writing ;) as because I thus lost no opportunity of
advancing the interests of the public, as far as in me
lay, and since thus likewise, if my writings possess
any value, those into whose hands they may fall
after my death may be able to put them to what use
they deem proper. But I resolved by no means to
consent to their publication during my lifetime, lest
either the oppositions or the controversies to which
they might give rise, or even the reputation, such as
it might be, which they would acquire for me,
should be any occasion of my losing the time that I
had set apart for my own improvement. For
though it be true that every one is bound to promote
to the extent of his ability the good of others, and
that to be useful to no one is really to be worthless,
yet it is likewise true that our cares ought to extend
beyond the present; and it is good to omit doing

DISCOURSE ON METftOD. 71

what might perhaps bring some profit to the living,
when we have in view the accomplishment of other
ends that will be of much greater advantage to
posterity And in truth, I am quite willing it
should be known that the little 'I have hitherto
learned is almost nothing in comparison with that of
which I am ignorant, and to the knowledge of which
I do not despair of being able to attain for it is
much the same with those who gradually discover
truth in the Sciences, as with those who when
growing rich find less difficulty in making great
acquisitions, than they formerly experienced when
poor in making acquisitions of much smaller
amount. Or they may_be_compare_d to the com
manders of anniea, whose forces, usually increase in
proportion jtqjheir victories, and who need greater
prudence to keep together the residue of their troops
after a defeat than after a victory to take towns and
provinces. For he truly engages in battle who
endeavours to surmount all the difficulties and errors
which prevent him from reaching the knowledge of
truth, and he is overcome in fight who admits a false
opinion touching a matter of any generality and
importance, andJie.-i'equires thereafter much more
skill to recover Jns former position than_tp_make
great advances., when -once, in possession, of thor
oughly ascertained, principles. As for myself, if I
have succeeded in discovering any truths in the
Sciences, (and I trust that what is contained in this
volume* will show that I have found some,) I can
declare that they are but the consequences and
*See p. 31, footnote.

72 DESCARTES.

results of five or six principal difficulties which I
have surmounted, and my encounters with which I
reckoned as battles^ in which victory declared for
me. I will not hesitate even to avow my belief
that nothing further is wanting to enable me fully
to realize my designs than to gain two or three
similar victories; and that I am not so far advanced
in years but that, according to the ordinary course
of nature, I may still have sufficient leisure for this
end. But I conceive myself the more bound to hus
band the time that remains the greater my expecta
tion of being able to employ it aright, and I should
doubtless have much to rob me of it, were I to pub
lish the principles of my Physics: for although they
are almost all so evident that to assent to them no
more is needed than simply to understand them, and
although there is not one of them of which I do not
expect to be able to give demonstration, yet, as it is
impossible that they can be in accordance with all
the diverse opinions of others, I foresee that I
should frequently be turned aside from my grand
design, on occasion of the opposition which they
would be sure to awaken.

It may be said, that these oppositions would be
useful both in making me aware of my errors, and,
if my speculations contain anything of value, in
bringing others to a fuller understanding of it; and
still farther, as many can see better than one, in
leading others who are now beginning to avail them
selves of my principles, to assist me in turn with
their discoveries. But though I recognise my
extreme liability to error, and scarce ever trust to

DISCOURSE ON METHOD. 73

the first thoughts which occur to me, yet the experi
ence I have had of possible objections to my views
prevents me from anticipating- any profit from
them. For I have already had frequent proof of the
judgments, as well of those I esteemed friends, as
of some others to whom I thought I was an object
of indifference, and even of some whose malignity
and envy would, I knew, determine them to
endeavour to discover what partiality concealed
from the eyes of my friends. But it has rarely hap
pened that anything has been objected to me which
I had myself altogether overlooked, unless it were
something far removed from the subject: so that I
have never met with a single critic of my opinions
who did not appear to me either less rigorous or less
equitable than myself. And further, I have never
observed that any truth before unknown has been
brought to light by the disputations that are prac
tised in the Schools ; for while each strives for the
victory, each is much more occupied in making the
best of mere verisimilitude, than in weighing the
reasons on both sides of the question; and those
who have been long good advocates are not after
wards on that account the better judges.

As for the advantage that others would derive
from the communication of my thoughts, it could
not be very great; because I have not yet so far
prosecuted them as that much does not remain to be
added before they can be applied to practice. And
I think I may say without vanity, that if there is
any one who can carry them out that length, it must
be myself rather than another: not that there may

74

DESCARTES.

not be in the world many minds incomparably
superior to mine, but because one cannot so well
seize a thing- and make it one's own, when it has
been learned from another, as when one has himself
discovered it. And so true is this of the present
subject that, though I have often explained some of
my opinions to persons of much acuteness, who,
whilst I was speaking, appeared to understand them
very distinctly, yet, when they repeated them, I
have observed that they almost always changed
them to such an extent that I could no longer
acknowledge them as mine. I am glad, by the way,
to take this opportunity of requesting posterity
never to believe on hearsay that anything has pro
ceeded from me which has not been published by
myself; and I am not at all astonished at the extrav
agances attributed to those ancient philosophers
whose own writings we do not possess; whose
thoughts, however, I do not on that account suppose
to have been really absurd, seeing they were among
the ablest men of their times, but only that these
have been falsely represented to us. It is observ
able, accordingly, that scarcely in a single instance
has any one of their disciples surpassed them ; and
I am quite sure that the most devoted of the present
followers of Aristotle would think themselves happy
if they had as much knowledge of nature as he pos
sessed, were it even under the condition that they
should never afterwards attairL_tn_lr[^1rier In this
respect they are like the ivy which never strives to
rise above the tree that sustains it, and which fre
quently even returns downwards when it has

DISCOURSE ON METHOD. 75

reached the top ; for it seems to me that they also
sink, in other words, render themselves less wise
than they would be if they gave up study, who, not
contented with knowing all that is intelligibly
explained in their author, desire in addition to find
in him the solution of many difficulties of which he
says not a word, and never perhaps so much as
thought. Their fashion of philosophizing, however,
is well suited to persons whose abilities fall below
mediocrity ; for the obscurity of the distinctions and
principles of which they make use enables them to
speak of all things with as much confidence as if
they really knew them, and to defend all that they
say on any subject against the most subtle and skil
ful, without its being possible for any one to convict
them of error. In this they seem to me to be like a
blind man, who, in order to fight on equal terms
with a person that sees, should have made him
descend to the bottom of an intensely dark cave:
and I may say that such persons have an interest in
my refraining from publishing the principles of the
Philosophy of which I make use ; for, since these
are of a kind the simplest and most evident, I
should, by publishing them, do much the same as if
I were to throw open the windows, and allow the
light of day to enter the cave into which the com
batants had descended. But even superior men
have no reason for any great anxiety to know these
principles, for if what they desire is to be able to
speak of all things, and to acquire a reputation for
learning, they will gain their end more easily by
remaining satisfied with the appearance of truth,

76 DESCARTES.

which can be found without much difficulty in all
sorts of matters, than by seeking the truth itself
which unfolds itself but slowly and that only in
some departments, while it obliges us, when we
have to speak of others, freely to confess our igno
rance. If, however, they prefer the knowledge of
some few truths to the vanity of appearing igno
rant of none, as such knowledge is undoubtedly much
to be preferred, and, if they choose to follow a
course similar to mine, they do not require for this
that I should say anything more than I have already
said in this Discourse. For if they are capable of
making greater advancement than I have made,
they will much more be able of themselves to dis
cover all that I believe myself to 'have found; since
as I have never examined aught except in order, it
is certain that what yet remains to be discovered is
in itself more difficult and recondite, than that which
I have already been enabled to find, and the grati
fication would be much less in learning it from me
than in discovering it for themselves. Besides this,
the habit which they will acqiiire, by seeking first
what is easy, and then passing onward slowly and
step by step to the more difficult, will benefit them
more than all my instructions. Thus, in my own
case, I am persuaded that if I had been taught from
my youth all the truths of which I have since
sought out demonstrations, and had thus learned
them without labour, I should never, perhaps, have
known any beyond these; at least, I should never
have acquired the habit and the facility which I
think I possess in always discovering new truths in

DISCOURSE ON METHOD. 77

proportion as I give myself to the search. And, in
a single word, if there i~ any work in the world
which cannot be so well finished by another as by
him who h^s commenced it, it is that at which I
labour.

It is true, indeed, as regards the experiments
which may conduce to this end, that one man is not
equal to the task of making them all , but yet he can
advantageously avail himself, in this work, of no
hands besides his own, unless those of artisans, or
parties of the same kind, whom he could pay, and
whom the hope of gain (a means of great efficacy)
might stimulate to accuracy in the performance of
what was prescribed to them. For as to those who,
through curiosity or a desire of learning, of their
own accord perhaps, offer him their services,
besides that in general their promises exceed their
performance, and that they sketch out fine designs
of which not one is ever realized, they will, without
doubt, expect to be compensated for their trouble
by the explication of some difficulties, or, at least,
by compliments and useless speeches, in which he
cannot spend any portion of his time without loss to
himself. And as for the experiments that others
have already made, even although these parties
should be willing of themselves to communicate
them to him, (which is what those who esteem them
secrets will never do,) the experiments are, for the
most part, accompanied with so many circumstances
and superfluous elements, as to make it exceed
ingly difficult to disentangle the truth from its
adjuncts; besides, he will find almost all of them so

^S DESCARTES.

ill described, or even so false, (because those who
made them have wished to see in them only such
facts as they deemed comformable to their prin
ciples,) that, if in the entire number there should be
some of a nature suited to his purpose, still their
value could not compensate for the time that would
be necessary to make the selection. So that if
there existed any one whom we assuredly knew to
be capable of making discoveries of the highest kind,
and of the greatest possible utility to the public , and
if all other men were therefore eager by all means
to assist him in successfully prosecuting his designs,
I do not see that they could do aught else for him
beyond contributing to defray the expenses of the
experiments that might be necessary; and for the
rest, prevent his being deprived of his leisure by
the unseasonable interruptions of any one. But
besides that I neither have so high an opinion of
myself as to be willing to make promise of anything
extraordinary, nor feed on imaginations so vain as
to fancy that the public must be much interested in
my designs; I do not, on the other hand, own a soul
so mean as to be capable of accepting from any one
a favour of which it could be supposed that I was
unworthy.

These considerations taken together were the
reason why, for the last three years, I have been
unwilling to publish the Treatise I had on hand, and
why I even resolved to give publicity during my life
to no other that was so general, or by which the
principles of my Physics might be understood. But
since then, two other reasons have come into opera-

DISCOURSE ON METHOD. 79

tion that have determined me here to subjoin some
particular specimens, and give the public some
account of my doings and designs. Of these con- .
siderations, the first is, that if I failed to do so,
many who were cognizant of my previous intention
to publish some writings, might have imagined that
the reasons which induced me to refrain from so
doing, were less to my credit than they really are ;
for although I am not immoderately desirous of
glory, or even, if I may venture so to say, although
I am averse from it in so far as I deem it hostile to
repose which I hold in greater account than aught
else, yet, at the same time, I have never sought to
conceal my actions as if they were crimes, nor made
use of many precautions that I might remain
unknown; and this partly because I should have
thought such a course of conduct a wrong against
myself, and partly because it would have occasioned
me some sort of uneasiness which would again have
been contrary to the perfect mental tranquillity
which I court. And forasmuch as, while thus
indifferent to the thought alike of fame or of forget-
fulness, I have yet been unable to prevent myself
from acquiring some sort of reputation, I have
thought it incumbent on me to do my best to save
myself at least from being ill-spoken of. The other
reason that has determined me to commit to writing
these specimens of philosophy is, that I am becom
ing daily more and more alive to the delay which my
design of self-instruction suffers, for want of the
infinity of experiments I require, and which it is
impossible for me to make without the assistance of

80 DESCARTES.

others : and, without flattering myself so much as to
expect the public to take a large share of my inter
ests, I am yet unwilling to be found so far wanting
in the duty I owe to myself, as to give occasion to
those who shall survive me to make it matter of
reproach against me some day, that I might have
left them many things in a much more perfect state
than I have done, had I not too much neglected to
make them aware of the ways in which they could
have promoted the accomplishment of my designs.
And I thought that it was easy for me to select
some matters which should neither be obnoxious
to much controversy, nor should compel me to
expound more of my principles than I desired, and
which should yet be sufficient clearly to exhibit what
I can or cannot accomplish in the Sciences.
Whether or not I have succeeded in this it is not for
me to say; and I do not wish to forestall the judg
ments of others by speaking myself of my writings;
but it will gratify me if they be examined, and, to
afford the greater inducement to this, I request all
who may have any objections to make to them, to
take the trouble of forwarding these to my pub
lisher, who will give me notice of them, that I may
endeavour to subjoin at the same time my reply;
and in this way readers seeing both at once will
more easily determine where the truth lies ; for I do
not engage in any case to make prolix replies, but
only with perfect frankness to avow my errors if I
am convinced of them, or if I cannot perceive
them, simply to state what I think is required for
defence of the matters I have written, adding

DISCOURSE ON METHOD. 8l

thereto no explication of any new matter that it may
not be necessary to pass without end from one thing
to another.

If some of the matters of which I have spoken in
the beginning of the Dioptrics and Meteorics should
offend at first sight, because I call them hypotheses
and seem indifferent about giving proof of them, I
request a patient and attentive reading of the whole,
from which I hope those hesitating will derive satis
faction , for it appears to me that the reasonings are
so mutually connected in these Treatises, that, as
the last are demonstrated by the first which are
their causes, the first are in their turn demonstrated
by the last which are their effects. Nor must it be
imagined that I here commit the fallacy which the
logicians call a circle ; for since experience renders
the majority of these effects most certain, the causes
from which I deduce them do not serve so much to
establish their reality as to explain their existence ;
but on the contrary, the reality of the causes is
established by the reality of the effects. Nor have
I called them hypotheses with any other end in view
except that it may be known that I think I am able
to deduce them from those first truths which I have
already expounded; and yet that I have expressly
determined not to do so, to prevent a certain class
of minds from thence taking occasion to build some
extravagant Philosophy upon what they may take to
be my principles, and my being blamed for it. I
refer to those who imagine that they can master in a
day all that another has taken twenty years to
think out, as soon as he has spoken two or three

82 DESCARTES.

words to them on the subject; or who are the more
liable to error and the less capable of perceiving
truth in very proportion as they are more subtle and
lively. As to the opinions which are truly and!
wholly mine, I offer no apology for them as new, —
persuaded as I am that if their reasons be well con
sidered they will be found to be so simple and so
conformed to common sense as to appear less
extraordinary and less paradoxical than any others
which can be held on the same subjects; nor do I
even boast of being the earliest discoverer of any of
them, but only of having adopted them, neither
because they had nor because they had not been held
by others, but solely because Reason has convinced
me of their truth.

Though artisans may not be able at once to
execute the invention which is explained in the
Dioptrics, I do not think that any one on that
account is entitled to condemn it, for since address
and practice are required in order so to make and
adjust the machines described by me as not to over
look the smallest particular, I should not be less
astonished if they succeeded on the first attempt
than if a person were in one day to become an
accomplished performer on the guitar, by merely
having excellent sheets of music set up before him.
And if I write in French, which is the language of
my country, in preference to Latin, which is that of
my preceptors, it is because I expect that those who
make use of their unprejudiced natural Reason will
be better judges of my opinions than those who give
hee3 to the writings of the ancients only ; and as for

DISCOURSE ON METHOD. 83

those who unite good sense with habits of study,
whom_alone,I desire for judges, they will not, I feel
assured, be s^_rjartial_tp_JLatin as to refuse to listen
to my reasonings merely because I expound them
in the_vulgar Tongue.

In conclusion, I am unwilling here to say anything
very specific of the progress which I expect to make
for the future in the Sciences, or to bind myself to
the public by any promise which I am not certain of
being able to fulfil ; but this only will I say, that I
have resolved to devote what time I may still have
to live to no other occupation than that of endeavour
ing to acquire some knowledge of Nature, \vhich
shall be of such a kind as to enable us therefrom to
deduce rules in Medicine of greater certainty than
those at present in use; and that nr- inclination is
so much opposed to all other pursuits, especially to
such as cannot be useful to some without being
hurtful to others, that if, by any circumstances, I
had been constrained to engage in such, I do not
believe that I should have been able to succeed. Of
this I here make a public declaration, though well
aware that it cannot serve to procure for me any
consideration in the world, which, however, I do not
in the least affect; and I shall always hold myself
more obliged to those through whose favour I am
permitted to enjoy my retirement without inter
ruption than to any who might offer me the highest
earthly preferments.

DESCARTES LITERATURE.

EDITIONS:

Opera. Latin edition of his works. Amsterdam. 1650 ff.

Oeuvres Completes. Ed. Cousin. Paris. 1824-2(3. 11 vol. in
8vo.

Oeuvres Philosophiques. Ed. Gamier. Paris. 1834. 4 vol.
in 8vo.

Oeuvres Completes. Ed. Ch. Adam et Tannery. Paris. In
4to. (The first volume appeared in 1896, the second in
1898.)

Oeuvres Choisies. Ed. Jules Simon. 1 vol. Paris: Char-
pentier.

Oeuvres Choisies. Ed. Jules Simon. 1 vol. Paris: Gamier.

The Method, Meditations, and Selections from the Principles.
Translated into English by J. Veitch. llth ed. Edin
burgh & London. 1897. (Authorized reprint of The
Method of this edition. Chicago: Open Court Pub. Co.
1899.)

La Gcometrie. New reprint. Paris: A. Hermann. 1896.

Meditations. Translated into English by Lowndes. Lon
don. 1878.

Extracts from Descartes' 's Writings: Rules for the Direction
of the Mind; the Meditations (in part); the World; Pas
sions ^f the Soul, etc. By H. A. P. Torrey. New York.
1892.

German Translations: (1) the Method, (2) the Principia,
(3) the Passions of the Soul, (4) the Meditations. Heidel
berg: George Weiss. 1 or 4 vols.
FOR REFERENCE:

L. Ltvy-Bruhl. History of Modern Philosophy in France.
Chicago: The Open Court Pub. Co., 1899.

F. Bouillier. Histoire de la Philosophic Carte*sienne. 2 vol.
Paris. 1868.

84

DESCARTES. 85

Liard. Descartes. Paris: Alcan. 1881.

Fouillee. Descartes. Paris: Hachette. 1893.

Revue de MHaphysique et de Morale. Descartes number.

1896.

Ersch and Cruder. Encyclopadie.

Mahaffy. Descartes. Edinburgh and Philadelphia. 188'.
Wallace. Art. " Descartes" in Encyclopaedia Britannica.
Schaarschmidt, C. Descartes & Spinoza. Bonn. 1850.
Huxley. Essays.
Natorpt P. Descartes' Erkenntnistheorie. Marburg. 1882.

INDEX.

Accidents, 2.
Algebra, 18, 21.
Analysis, 17, 18, 39.
Anatomy, 50.

Animals, are machines, 60.
Aristotle, 74.
Arithmetic, 22.
Arteries, 50 et seq.
Astronomy, 45.
Authority, 14.
Automata, 59 et seq.

Bad, 30.

Battles of i.nought, 72.

Beliefs, 15, 25.

Blood, circulation of the, 54.

Book's, 5.

Brutes, soul of, 61, 62.

Buildings, 12, 24.

Cave, dark, 75.

Certainty, 36.

Change, 26.

Chaos, 46, 48.

Characters, brief, 21.

Chinese, 17.

Cle'ar, 36.

Clearly, 19.

Clearness, 41.

Clock, 54, 63.

Cogito, ergo sum, 35 et seq.

Common sense, 59.

Composition, 38.

Content, 27.

Controversy, 72.

Cosmogony, 46.

Country, 24.

Criticism, self. 73.

Custom, 10.

Demonstrations of geometry, 39.
Descartes, his method, an auto
biography. 4.

Digestion, 57.
Dioptrics, 82.

Discovery, 74, 76.
Distinctness, 36, 41.
Doubt, 30, 36.

Dreaming, 41.
Dreams, 35, 43.

Dress, 17.

Earth, 47.

Easiest objects. 19 et seq.
Enumeration, 19, 22.
Errors, 10.
Existence, 41.
Experiments, 67 et seq., 77.
External, things, 27.
Extremes, 25.

Faith, 2J.30.
First causes, 68.
Fortune, 28.
France, 16.

Galileo, 64.

Geometers, reasonings of, 19.

Geometry, 17, 39.

Germany, 11, 16.

God, 29, 37 et seq., 40 et seq., 43, 44,

60, 68.
Good. 30.
Good sense, 1. f

Harvey, 54.

Heart, description of the, 50 et sety.

Heat, 48.

Highways, 15, 16,

History, 5.

Holland, 33.

Houses, 13,24.

Humours of the body, 58.

Hypotheses, 81.

DESCARTES.

87

Ideas, 40.

Imagination, 40, 43
Immortality, 63.
Imperfection, 42.
Infinite Being, 42.
Ivy, the, 74.

Language, 60 et seq.

Languages, 5.

Laws, 12, 18; natural, 44, 46, 48.

Letters, 9.

Light, 45, 47.

Logic, 18.

Lully, art of, 18.

Machines, GO etseq.

Man, 45.

Manners, 10.

Mathematics, 5, 7, 30, 31.

Maxims, moral, 24 et seq.

Meaning, 61.

Mechanics, 58.

Medicine, 66, 83.

Mediocrity, 75.

Men, two classes of, 15.

Method, 2,3,17, 18, 22,29,31.

Moderate, 25.

Moralists, ancient, 7.

Morals, provisory code of, 24.

Nutrition, 58.

Occupations of men, 28.
Opinions, 14, 16 et seq., 25.
Order, 19, 22.

Painters, 45.

Perfection, 36, 37.

Perfect Being, 39.

Philosopher, occupation of a. 3.

Philosophizing, the old, 7f>.

Philosophy, 5, 8, 22, 66.

Physics, 64 et seq., 72.

Poetry, 5, 7.

Posterity, 71.

Practical, 66.

Precepts, Descartes's, 19.

rinciples, 68.

robability, 27.
Proportions, 20.
'ublic interest, 70.

Reason, 1, 7, 10, 13, 16, 17, 29. 43, 61, 82.

Reformers, 65.

Reforms, 15.

Religion, 12

Resolute, 26.

Respiration, 5V

Rhetoric, 7

Romance, 6.

Rules, Descartes's, 19.

Savages, 16.

Sceptics, 30.

Schools, studies of the, 5.

Sciences, 4 et seq., 8, 13, 14, 22.

Self, conquest of, 27.

Sense, 1.

Senses. 42, 59.

Simplest objects, 19 et seq.

Soul, 35 et seq., 49 et seq., 63 et sec.

Sparta, 12.

Speech, 60 et seq.

Spirits, animal, 58 et 3eq.

Stars, 47.

States, 14.

Suffrages, plurality of, 17.

Surgeons, 54.

Theology, 5, 7.
Thinking is being, 36.
Tides, 47.
Travelling. 6, 30.
Triangle, 3'.).
True, 41.

Truth, 9, 13, 16, 17, 20. 22, 25, 29, 32, 36,
1 43, 76.

Understanding, 40.
Vows, 25.

World, the great book 01 the, 9.
Worlds, other. 46.

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