Kant's critical philosophy for English readers

KANT'S CRITICAL PHILOSOPHY

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KANT'S
CRITICAL PHILOSOPHY

FOR ENGLISH READERS

BY

JOHN P. MAHAFFY, D.D.

FELLOW AND TUTOR OF TRINITY COLLEGE, DUBLIN
PROFESSOR OF ANCIENT HISTORY IN THE UNIVERSITY OF DUBLIN

JOHN H. BERNARD, B.D.

FELLOW OF TRINITY COLLEGE, DUBLIN
ARCHBISHOP KING'S LECTURER IN DIVINITY IN THE UNIVERSITY OF DUBLIN

A NEW AND COMPLETED EDITION

VOL. II.
THE PROLEGOMENA TRANSLATED, WITH NOTES AND

VANNEVAR & co

438 YONGE STREET.

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PREFACE

THE following translation of Kant's Prolegomena to
any Future Metaphysic is not the first which has been
laid before the English public. Richardson published
a translation in i 8 I 8, which is now so rare that Mr.
Lewes, though his knowledge of this sort of literature
was exceedingly wide, seemed to be unaware of its ex
istence.1 When I had completed part of the task, I
chanced to find a copy of this book, which is full of
errors and inaccuracies, but yet has merit enough to
have escaped oblivion, had the author published -it at a
time when anything whatever was known in England
about Kant's philosophy. I was tempted to use it
in some sections as the basis of the present work, in
order to relieve myself of the tedium of writing out
the whole translation. But so many corrections
were necessary that it hardly saved me any trouble,
and probably my book may not have been improved
by putting the new wine into the old bottles. Still
I am answerable for the general correctness of the

1 Hist, of Phil. ii. p. 441, note.

vi PREFACE

following translation, and believe that, clumsy as it
may be, it is far more readable than Kant's original.
There are at least twice as many full stops as in the
German ; sundry missing verbs and pronouns have
been supplied, and I have done what I could to
make the terms more precise without damaging the
faithfulness of the reproduction.

There is also recently published a good version
by Mr. Bax, who had the advantage of using the
First Edition of the present work, which appeared
in 1872.

I need say nothing here of the scope of the
Prolegomena, as Kant himself has explained it in his
Introduction, but lay special stress on the fact, that
while prior in time to the Second Edition of the
Kritik, and professedly expounding the First Edition,
its attitude is completely that of the Second Edition
on the great question of idealism. When Schopen
hauer's school talk of Kant's supposed change of
opinion between 1781 and 1787, they should be
reminded that in 1783 he wrote the Prolegomena,
not to refute, but to explain his original Kritik, and
that in no work has he spoken out more precisely
against absolute idealism.

Most of the terms used do not require any
special explanation, but the following points may
be worth noticing. As in Vol. L, knowledge and
cognition are both used, and used synonymously, on
account of the convenience and precision of the

PREFACE vil

forms cognitive and cognise, while the Saxon word is
clearer to most readers. I have frequently printed
the word Reason with a capital, where it means a
special faculty, as distinguished from the under
standing, but as Kant himself often passes back to
the wider meaning, it was impossible to distinguish
all the individual occurrences of the more special
meaning and to do more than call attention to the
distinction. In the case of another word I have
taken a liberty which appears to be an improvement
on the original. While Kant uses Begriff as synony
mous with our concept, he also uses it for those
vaguer mental representations which are under no
category, as, for example, God and Infinity. In
these cases I have used the word notion, as being
vaguer than concept, and may call the reader's atten
tion to the curious fact that the Germans are not
supplied with a special word to indicate a vaguer
thought than a concept. Kant's Vorstellnng includes
intuitions, his Idee has a quite special meaning.

Apart from nomenclature, I have in many
places endeavoured to bring out the point of the
argument, by trifling additions or modifications —
so trifling that they will not appear without a
careful comparison with the original. It was
indeed suggested to me in some of these places to
translate quite literally, and leave the reader to
solve the difficulty left by Kant. This indeed is
the plan followed by Mr. Bax. But I venture to

viii PREFACE

hope that nowhere has the sense of the original
been changed, and it is better to run the risk of a
mistake than to put down anything that does
not convey a distinct idea to the reader's mind.
It is of course far more agreeable to paraphrase
than to translate, and as the Kritik is accessible
in English, this course was adopted in the former
volume ; but it is due to Kant to put his Pro
legomena in all their homeliness literally before the
reader, that he may judge of the accuracy of the
various commentators and critics who discuss it.

I have reprinted in the Appendix the suppressed
passages of Kant's First Edition of the Kritik.
The text of the Prolegomena and of these Appen
dices has been carefully revised by Mr. Bernard,
and many improvements made. We have also
given in brackets the paging of the original edition,
for the sake of the references made to it in our first

Voluma J. P. MAHAFFY.

TRINITY COLLEGE, DUBLIN,
June 6th, 1889.

CONTENTS

PREFACE
CONTENTS

PAGE
V

INTRODUCTION i

PREAMBLE ON THE PECULIARITIES OF ALL METAPHYSICAL
COGNITION

Of the Sources of Metaphysic . . . . . .13

Concerning the kind of Cognition which can alone be called

Metaphysical . . . . . . . . .14

Observations on the General Division of Judgments into

Analytical and Synthetical . . . . . . 19

The General Question of the Prolegomena. — Is Metaphysic at all

possible ? * t . . . . .20

The General Problem : How is Cognition from Pure -Reason

possible ? . . ; . . . .26

How are Synthetic Propositions a priori possible ? . . . 27

FIRST PART OF THE GENERAL TRANSCENDENTAL PROBLEM
How is Pure Mathematic possible ? . . . . . 32*

SECOND PART OF THE GENERAL TRANSCENDENTAL PROBLEM

How is the Pure Science of Nature [Physic] possible
Logical Table of Judgments .

49
59

CONTENTS

PAGE

Transcendental Table of the Pure Concepts of the Under
standing ......... 60

Pure Physiological Table of the Universal Principles of the

Science of Nature ........ 60

How is Nature itself possible ? . . . . . .77

APPENDIX TO THE PURE SCIENCE OF NATURE
Of the System of the Categories . . . . . .83

THIRD PART OF THE MAIN TRANSCENDENTAL PROBLEM

How is Metaphysic in General possible ? .... 89

Prefatory Remark to the Dialectic of Pure Reason 95

The Psychological Idea ....... 96

The Cosmological Idea ..... .102

Table of Dialectical Assertions of Pure Reason . .103

The Theological Idea . . . . . . .114

General Remark on the Transcendental Ideas . .115

CONCLUSION. — On the Bounds of Pure Reason . .116

SOLUTION OF THE GENERAL QUESTION OF THE PROLEGOMENA

How is Metaphysic possible as a Science ? . . . 135

APPENDIX. — On what can be done to make Metaphysic actual as

a Science ......... 143

SPECIMEN OF A JUDGMENT ON THE KRITIK PRIOR TO

ITS EXAMINATION 145

APPENDIX A

ON THE DEDUCTION OF THE PURE CONCEPTS OF THE
UNDERSTANDING

Of the a priori Grounds of the Possibility of Experience . 155

Of the Relation of the Understanding to Objects in General, and

of the Possibility of Cognising them a priori . . . 1 70
Summary Statement of the Correctness and Possibility of this
and no other Deduction of the Pure Concepts of the
Understanding . . . . , . . 180

CONTENTS xi

APPENDIX B

p PAGE

^DISTINCTION BETWEEN NOUMENA AND PHENOMENA . 1 82

APPENDIX C

THE FIRST PARALOGISM, OF SUBSTANTIALITY

Kritik of the First Paralogism of Pure Psychology . . .189
The Second Paralogism, of Simplicity . . . . .191

Kritik of the Second Paralogism of Transcendental Psychology 191
Third Paralogism, of Personality . . . . . .199

Kritik of the Third Paralogism of Transcendental Psychology . 199
The Fourth Paralogism, of Ideality (of External Relations) . 203
Kritik of the Fourth Paralogism of Transcendental Psychology 203
'Reflection concerning the whole of Pure Psychology, as an

Appendix to these Paralogisms . . . . .214

APPENDIX D

PART OF THE 9TH SECTION OF THE ANTINOMY OF THE
PURE REASON

Possibility of Causality through Freedom in Harmony with the

Universal Law of Natural Necessity . . . .232

Further Elucidation of the Cosmological Idea of Freedom in

Harmony with the Universal Law of Natural Necessity . 235

KANT'S

PROLEGOMENA TO ANY FUTURE
METAPHYSIC

INTRODUCTION

THESE Prolegomena are for the use, not of pupils, but of
future teachers, and are intended to serve even the latter,
not in arranging their exposition of an existing science, but
in discovering this science itself.

There are learned men, to whom the history of philo
sophy (both ancient and modern) is philosophy itself; for
such the present Prolegomena are not written. They must
wait till those who endeavour to draw from the fountain of
reason itself have made out their case ; it will then be the
historian's turn to inform the world of what has been done.
Moreover, nothing can be said, which in their opinion has
not been said already, and indeed this may be applied as
an infallible prediction to all futurity; for as the human
reason has for many centuries pursued with ardour infinitely
various [2] objects in various ways, it is hardly to be
expected that we should not be able to match every new
thing with some old thing not unlike it.

My object is to persuade all who think Metaphysic

II B

2 PROLEGOMENA TO METAPHYSIC [2-3

worth studying, that it is absolutely necessary to adjourn
for the present this (historical) labour, to consider all that
has been done as undone, and to start first of all with the
question, 'Whether such a thing as metaphysic be at all
possible?'

If it be a science, how comes it that it cannot, like other
sciences, obtain for itself an universal and permanent
recognition? If not, how is it ever making constant
pretensions, under this supposition, and keeping the human
mind in suspense with hopes that never fade, and yet are
never fulfilled ? Whether then, as a result, we demonstrate
our knowledge or our ignorance, we must come once for all
to a definite conclusion about the nature of this pretended
science, which cannot possibly remain on its present footing.
It seems almost ridiculous, while every other science is
continually advancing, that in this, which would be very
Wisdom, at whose oracle all men inquire, we should per
petually revolve round the same point, without gaining a
single step. And so its followers having melted away, we
do not find men who feel able to shine in other sciences
venturing their reputation here, where everybody, however
ignorant in other matters, pretends to deliver a final verdict,
as in this domain [3] there is as yet no certain weight and
measure to distinguish sound knowledge from shallow talk.

But after long elaboration of a science, when men begin
to wonder how far it has advanced, it is not without pre
cedent that the question should at last occur, whether and
how such a science be even possible? For the human
reason is so constructive, that it has already several times
built up a tower, and then razed it to examine the nature
of the foundation. It is never too late to mend ; but if the
change comes late, there is always more difficulty in setting
it going.

3-4] INTRODUCTION

The question whether a science be possible, presupposes
a doubt as to its actuality. But such a doubt offends the
men whose whole possessions consist of this supposed
jewel; hence he who raises the doubt must expect op
position from all sides. Some, in the proud consciousness
of their possessions, which are ancient, and therefore con
sidered legitimate, will take their metaphysical compendia
in their hands, and look down on him with contempt ;
others, who never see anything except it be identical with
what they have seen before, will not understand him, and
everything will remain for a time, as if nothing had happened
to excite the concern, or the hope, for an impending
change.

Nevertheless, I venture to predict that the independent
reader of these Prolegomena will not only doubt his previous
science, but ultimately be [4] fully persuaded, that it cannot
exist without satisfying the demands here stated, on which
its possibility depends ; and, as this has never been done,
that there is, as yet, no such thing as Metaphysic. But as
it can never cease to be in demand —

1 Rusticus expectat, dum defluat amnis, at ille
Labitur et labetur in omne volubilis aevum ; ' —

since the interests of mankind are interwoven with it so
intimately, he must confess that a radical reform, or rather
a new birth of the science after an original plan, must be
unavoidably at hand, however men may struggle against it
for a while.

Since the Essays of Locke and Leibnitz, or rather since
the origin of metaphysic so far as we know its history,
nothing has ever happened which might have been more
decisive to the fortunes of the science than the attack made
upon it by David Hume. He threw no light on this

4 PROLEGOMENA TO METAPHYSIC [4-5

species of knowledge, but he certainly struck a spark from
which light might have been obtained, had it caught a
proper substance to nurture and develop the flame.

Hume started chiefly from a single but important con
cept in Metaphysic — that of Cause and Effect (including
the deduced notions of action and power). He calls on
reason, which pretends to have generated this notion from
itself, to answer him with what right it thinks anything to
be so constituted, that if granted, something else must
necessarily be [5] granted thereby ; for this is the meaning
of the concept of cause. He demonstrated irresistibly that
it was perfectly impossible for reason to think such a com
bination by means of concepts and a priori — a combination
that contains necessity. We cannot at all see why, in
consequence of the existence of one thing, another must
necessarily exist, or how the concept of such a combination
can arise a priori. Hence he inferred, that reason was
altogether deluded by this concept, which it considered
erroneously as one of its children, whereas in reality the
concept was nothing but the bastard offspring of the
imagination, impregnated by experience, and so bringing
certain representations under the Law of Association. The
subjective necessity, that is, the custom which so arises, is
then substituted for an objective necessity from real know
ledge.1 Hence he inferred that the reason had no power
to think such combinations, even generally, because its
concepts would then be mere inventions, and all its pre
tended a priori cognitions nothing but common experiences
marked with a false stamp. In plain language there is not,
and cannot be, any such thing as metaphysic at all.2 This

1 Lit. insight. M.

2 Nevertheless Hume called this very destructive science metaphysic,
and attached to it great value. ' Metaphysic and morals (he says in the

6-7J INTRODUCTION

conclusion, however [6] hasty and mistaken, was at least
founded upon investigation, and the investigation deserved
to have suggested to the brighter spirits of his day a com
bined attempt at a happy solution of the problem proposed
by him, if such solution were possible. Thus a complete
reform of the science must have resulted.

But the perpetual hard fate of metaphysic would not allow
him to be understood. We cannot without a certain sense
of pain consider how utterly his opponents, Reid, Oswald,
Beattie, and even Priestley, missed the point of the problem.
For while they were ever assuming as conceded what he
doubted, and demonstrating with eagerness and often with
arrogance what he never thought of disputing, they so
overlooked his indication towards a better state of things,
that everything remained undisturbed in its old condition.

The question was not whether the concept of cause was
right, useful, and even indispensable with regard to our
knowledge of nature, for this Hume [7] had never doubted.
But the question to which Hume expected an answer was
this, whether that concept could be thought by the reason
a priori, and whether it consequently possessed an inner
truth, independent of all experience, and therefore applied
more widely than to the mere objects of experience. It
was surely a question concerning the origin^ not concerning
the indispensable use of the concept. Had the former
question been determined, the conditions of the use and

4th part of his Essays) are the most important branches of science ;
mathematics and physics are not worth half so much.' But the acute
author was here merely regarding the negative use arising from the
moderation of the extravagant pretensions of speculative reason, and
the complete settlement of the many endless and troublesome contro
versies that mislead mankind. He overlooked the positive injury which
results, if the reason be deprived of its most important prospects, which
can alone supply to the will the highest aim of all its efforts.

6 PROLEGOMENA TO METAPHYSIC [7-8

valid application of the concept would have been given
ip so facto.

But the opponents of the great thinker should have
probed very deeply into the nature of the reason, so far as
it concerns pure thinking, if they would satisfy the conditions
of the problem — a task which did not suit them. They
therefore discovered a more convenient means of putting on
a bold face without any proper insight into the question, by
appealing to the common sense of mankind. It is indeed a
great gift of God, to possess right, or (as they now call it)
plain common sense. But this common sense must be
shown practically, by well-considered and reasonable
thoughts and words, not by appealing to it as an oracle,
when you can advance nothing rational in justification of
yourself. To appeal to common sense, when insight and
science fail, and no sooner — this is one of the subtile
discoveries of modern times, by means of which the most
vapid babbler can safely enter the lists with the most
thorough- [8] going thinker, and hold his own. But as long
as a particle of insight remains, no one would think of
having recourse to this subterfuge. For what is it, but an
appeal to the opinion of the multitude, of whose applause
the philosopher is ashamed, while the popular and super
ficial man glories and confides in it? I should think
Hume might fairly have laid as much claim to sound sense
as Beattie, and besides to a critical understanding (such as
the latter did not possess), which keeps common sense
within such limits as to prevent it from speculating, or, if
it does speculate, keeps it from wishing to decide when it
cannot satisfy itself concerning its own principles. By this
means alone can common sense remain sound sense.
Chisels and hammers may suffice to work a piece of wood,
but for steel-engraving we require a special instrument.

8-9] INTRODUCTION

Thus common sense and speculative understanding are
each serviceable in their own way, the former in judgments
which apply immediately to experience, the latter when we
judge universally from mere concepts, as in metaphysic,
where that which calls itself (often per antiphrasiri) sound
common sense has no right to judge at all.

I honestly confess, the suggestion of David Hume was
the very thing, which many years ago first interrupted my
dogmatic slumber, and gave my investigations in the field
of speculative philosophy quite a new direction. I was far
from following him [9] in all his conclusions, which only
resulted from his regarding not the whole of his problem,
but a part, which by itself can give us no information. If
we start from a well-founded, but undeveloped, thought,
which another has bequeathed to us, we may well hope by
continued reflection to advance farther than the acute man,
to whom we owe the first spark of light.

I therefore first tried whether Hume's objection could
not be put into a general form, and soon found that the
concept of the connexion of cause and effect was by no
means the only one by which the understanding thinks the
connexion of things a priori, but rather that metaphysic
consists altogether of such connexions. I sought to make
certain of their number, and when I had succeeded in this
to my expectation, by starting from a single principle, I
proceeded to the deduction of these concepts, which I was
now certain were not deduced from experience, as Hume
had apprehended, but sprang from the pure understanding.
This deduction, which seemed impossible to my acute
predecessor, which had never even occurred to any one
else, though they were all using the concepts unsuspiciously
without questioning the basis of their objective validity —
this deduction was the most difficult task ever undertaken

8 PROLEGOMENA TO METAPHYSIC [9-11

in aid of metaphysic. More especially, no existing meta-
physic could assist me in the least, because this deduction
must prove the [10] very possibility of metaphysic. But as
soon as I had succeeded in solving Hume's problem not
merely in a particular case, but with respect to the whole
faculty of pure reason, I could proceed safely, though
slowly, to determine the whole sphere of pure reason
completely and from general principles, in its bounds, as well
as in its contents. This was what metaphysic required, in
order to construct its system safely.

But I fear that the carrying out of Hume's problem in its
widest extent (viz. my Kritik of the Pure Reason) will fare
as the problem itself fared, when first proposed. It will be
misjudged because it is misunderstood, and misunderstood
because men choose to skim through the book, and not to
think through it — a disagreeable task, because the work is
dry, obscure, opposed to all ordinary notions, and moreover
voluminous. I confess, however, I did not expect to hear
from philosophers complaints of want of popularity, enter
tainment, and facility, when the existence of a highly
esteemed and to us indispensable cognition is at stake,
which cannot be established otherwise than by the strictest
rules of scholastic accuracy. Popularity may follow, but is
inadmissible at the commencement. Yet as regards a certain
obscurity, arising partly from the extent of the plan, in
which the principal points of the investigation cannot be
easily gathered into view, the complaint is partly just, and
I intend to remove it by the present Prolegomena.

[u] The work which represents the pure faculty of
reason in its whole compass and bounds will always remain
the groundwork to which the Prolegomena, as a pre
liminary exercise, refer • for we must have that Kritik
completed as a science, systematically, in its minutest

n-12] INTRODUCTION

details, before we can think of letting Metaphysic appear on
the scene, or even have the most distant hope of attaining it.

We have been long accustomed to seeing antiquated
knowledge produced as new by being taken out of its
former context, and fitted into a suit of any fancy pattern
under new titles. Most readers will set out by expecting
nothing else from the Kritik ; but these Prolegomena may
persuade him that it is a perfectly new science, of which no
one has ever even thought, the very idea of which was
unknown, and for which nothing hitherto accomplished can
be of the smallest use, except it be the indication suggested
by Hume's doubts. Yet even he did not suspect such
a formal science, but ran his ship ashore, for safety's sake,
on scepticism, there to let it lie and rot ; whereas my object
is rather to give it a pilot, who, by means of safe astro
nomical principles drawn from a knowledge of the globe,
and provided with a complete chart and compass, may steer
the ship safely, whither he listeth.

If we proceed to a perfectly isolated and peculiar new
science, with the presupposition that we can judge it by
means of a supposed science that has [12] been already
acquired, whereas the reality of this latter must be first of all
thoroughly questioned — if we do this, it will make men
think they merely recognise old knowledge. For the terms
are similar, with this difference, that everything must appear
distorted, absurd, and unintelligible, because men start from
a mental attitude not the author's, but their own, which
through long habit has become a second nature. But the
voluminous character of the work, so far as it depends on
the subject, and not the exposition, its consequent un
avoidable dryness, and its scholastic accuracy — these are
qualities which can only benefit the science, though they
may damage the book.

io PROLEGOMENA TO METAPHYSIC [12-13

Few writers are gifted with the subtilty, and at the same
time with the grace of David Hume, or with the depth, as
well as the elegance, of Moses Mendelssohn. Yet I flatter
myself I might have made my own exposition popular, had
my object been merely to sketch out a plan, and leave its
completion to others, instead of having my heart in the
welfare of the science that I had so long pursued ;J in truth,
it required no little constancy, and even self-denial, to
postpone the sweets of an immediate [13] success to the
prospect of a slower, but more lasting reputation.

Making plans is often the occupation of a luxurious and
boastful mind, which thus obtains the reputation of a
creative genius, by demanding what it cannot itself supply ;
by censuring, what it cannot improve ; and by proposing,
what it knows not where to find. And yet something
more should belong to a sound plan of a general Kritik of
the Pure Reason than mere conjectures, if this plan is to
be other than the usual declamation of pious aspirations.
But pure reason is a sphere so separate and self-contained,
that we cannot touch a part without affecting all the rest.
We can therefore do nothing without first determining the
position of each part, and its relation to the rest ; for, as
our judgment cannot be corrected by anything without,
the validity and use of every part depends upon the relation
in which it stands to all the rest within the reason.

So in the structure of an organized body, the end of
each member can only be deduced from the full conception
of the whole. It may, then, be said of such a Kritik, that

\ 1 It is not a little remarkable that Kant expresses an exactly contrary
opinion in the conclusion to his Second Preface to the Kritik, where he
invites those who are possessed of the gift of popular teaching to assist
in explaining his system, and where he confesses himself devoid of it. —
Kritik) p. xlii. M.

13-15] INTRODUCTION n

it is never trustworthy except it be perfectly complete, down
to the smallest elements of the reason. In the sphere of
this faculty you can determine either everything or nothing.
But although a mere sketch, preceding the Kritik of Pure
Reason, would be unintelligible, unreliable and useless, it
is all the more useful as a [14] sequel. For so we are able
to grasp the whole, to examine in detail the chief points of
importance in the science, and to improve in many respects
our exposition, as compared with the first execution of the
work.

-Such is the plan sketched out in the following pages,
which, after the completion of the work, may be carried out
analytically r, though the work itself must absolutely be exe
cuted in the synthetical method, in order that the science may
present all its articulations, as the structure of a peculiar cog
nitive faculty, in their natural combination. But should any
reader find this plan, which I publish as the Prolegomena
to any future Metaphysic, itself difficult, let him consider
that every one is not bound to study Metaphysic, that there
are many minds which succeed very well, in genuine and
even deep sciences more closely allied to intuition, while
they cannot succeed in investigations proceeding only by
means of abstract concepts.1 In such cases men should
apply their talents to other subjects. But he that under
takes to judge, or still more to construct a system of Meta
physic, [15] must satisfy the demands here made, either by
adopting my solution, or by thoroughly refuting it, and
substituting another. To evade it is impossible.

1 It is nevertheless to be observed that a large proportion of great
metaphysicians have been trained and distinguished mathematicians.
The examples of Plato, Aristotle, Descartes, Leibnitz, Berkeley, and
Kant will occur to the reader. Even in the present day there are some
remarkable cases of this combination. M.

12 PROLEGOMENA TO METAPHYSIC [15

In conclusion, let it be remembered that this much-
abused obscurity — a very common cloak for men's own
laziness or stupidity — has its uses, since all who in other
sciences observe a prudent silence, in this speak authori
tatively, and decide boldly, because their ignorance is not
here contrasted with the knowledge of others. Yet it
does contrast with sound critical principles, which we may
therefore commend in the words of Virgil :

Ignavum, fucos, pecus a prsesepibus arcent.

[16] PROLEGOMENA

PREAMBLE ON THE PECULIARITIES OF ALL
METAPHYSICAL COGNITION

§ i. Of the Sources of Metaphysic

IF we wish to present a cognition as a science ', we must
first determine accurately the features which no other
science has in common with it — in fact its peculiarity,
otherwise the boundaries of all sciences become confused,
and none of them can be treated thoroughly according to
its nature.

This peculiarity may consist of a simple difference of
object, or of the sources of cognition, or of the kind of
cognition, or perhaps of all three conjointly. On this, there
fore, depends the idea of a possible science and its territory.

First, as concerns the sources of metaphysical cognition,
its very concept implies that they cannot be empirical. Its
principles (including not only its fundamental judgments,
but its fundamental concepts) must never be derived from
experience. It must not be physical but metaphysical
knowledge, viz. knowledge lying beyond experience. It
[17] can therefore have for its basis neither external ex
perience, which is the source of physics proper, nor internal,
which is the basis of empirical psychology. It is there-

i4 PROLEGOMENA TO METAPHYSIC [17-18

fore a priori knowledge, coming from pure Understanding
and pure Reason.

But so far Metaphysic would not be distinguishable from
pure Mathematic ; it must therefore be called pure philosophi
cal cognition ; and for the meaning of this term I refer to the
Kritikofthe Pure Reason, p. 4 3 5, where the distinction between
these two employments of the reason is sufficiently explained.
So far concerning the sources of metaphysical cognition.

§ 2. Concerning the Kind of Cognition which can alone be
called Metaphysical.

a. — Of the Distinction between Analytical and Synthetical
Judgments in general. The peculiarity of its sources demands
that metaphysical cognition must consist of nothing but a
priori judgments. But whatever be their origin, or their
logical form, there is a distinction in judgments, as to their
content, according to which they are either merely explicative,
adding nothing to the content of the cognition, or ampliative,
increasing the given cognition : the former may be called
analytical, the latter synthetical, judgments.

Analytical judgments express nothing in the predicate
but what has been already actually thought in [18] the con
cept of the subject, though not so distinctly or with the
same (full) consciousness.1 When I say : All bodies are
extended, I have not amplified in the least my concept of
body, but have only analysed it, as extension was really
thought to belong to that concept before the judgment was

1 The difference between an attribute obscurely felt to be in the sub
ject, and which requires a judgment to explicate it, and an attribute
necessarily joined to the subject, seems very small indeed. But a little
reflection will show us that we cannot think the subject without the
first, whereas the second is always seen to be an addition, even if neces
sary. M.

18-19] PECULIARITIES OF METAPHYSICAL COGNITION 15

made, though it was not expressed ; this judgment is there
fore analytical. On the contrary, this judgment, All bodies
have weight, contains in its predicate something not actually
thought in the general concept of body ; it amplifies my
knowledge by adding something to my concept, and must
therefore be called synthetical.

b. — The Common Principle of all Analytical Judgments
is the Law of Contradiction. All analytical judgments de
pend wholly on the law of Contradiction, and are in their
nature a priori cognitions, whether the concepts that supply
them with matter be empirical or not. For the predicate
of an affirmative analytical judgment is already contained in
the concept of the subject, of which it cannot be denied
without contradiction. In the same way its opposite is
necessarily denied of the subject in an analytical, but nega
tive, judgment, by the [19] same law1 of contradiction.
Such is the nature of the judgments : all bodies are ex
tended, and no bodies are unextended.

For this very reason all analytical judgments are a priori
even when the concepts are empirical, as, for example, Gold
is a yellow metal ; for to know this I require no experience
beyond my concept of gold as a yellow metal : it is, in fact,
the very concept, and I need only analyse it, without looking
beyond it elsewhere.

c. — Synthetical Judgments require a different Principle from
the Law of Contradiction. There are synthetical a posteriori
judgments of empirical origin; but there are also others which
are certain a priori, and which spring from pure Understand
ing and Reason. Yet they both agree in this, that they can
not possibly spring from the principle of analysis, or the law
of contradiction, alone ; they require a quite different prin
ciple, though, from whatever they may be deduced, they
must be subject to the law of contradiction, which must never

16 PROLEGOMENA TO METAPHYSIC [19-21

be violated, even though everything cannot be deduced
from it. I shall first classify synthetical judgments.

1. Empirical Judgments are always synthetical.1 [20]
For it would be absurd to base an analytical judgment on
experience, as our concept suffices for the purpose without
requiring any testimony from experience. That body is ex
tended, is a judgment established a priori, and not an
empirical judgment. For before appealing to experience,
we already have all the conditions of the judgment in the
concept (of the subject), from which we have but to elicit
the predicate according to the law of contradiction, and
thereby to become conscious of the necessity of the judgment,
which experience could not even teach us.

2. Mathematical Judgments are all synthetical. This
fact seems hitherto to have altogether escaped the observa
tion of those who have analysed the human reason ; it even
seems directly opposed to all their conjectures, though in-
contestably certain, and most important in its consequences.
For as it was found that the conclusions of mathematicians
all proceed according to the law of contradiction (as is de
manded by all apodeictic certainty), men [21] persuaded
themselves that the axioms (fundamental principles) were
known from the same law. This was a great mistake, for
a synthetical proposition can indeed be comprehended

1 See the very important passage in the First Edition of the Kritik,
quoted by me on p. 12 of Kuno Fischer's Commentary. 'In all syn
thetical judgments I must have something else (x) besides the concept
of the subject, to which the understanding must apply, in order to dis
cover a predicate not contained in the subject. In the case of empirical
judgments this x is the complete experience of the subject, and my
concept indicates that complete experience by means of a part of it, to
which I can add other facts of the same experience, as belonging to the
first.' It follows that these propositions, though synthetical as regards
the concept, become analytical as regards our experience when actually
completed. Cf. vol i. p. 36, note. M.

21-22] PECULIARITIES OF METAPHYSICAL COGNITION 17

according to the law of contradiction, but only by pre
supposing another synthetical proposition from which it
follows, never in itself.

First of all, we must observe that all proper mathematical
judgments are a priori^ and not empirical, because they
carry with them necessity, which cannot be obtained from
experience. But if this be not conceded to me, very good ;
I shall confine my assertion to pure Mathematic, the very
notion of which implies that it contains pure a priori and
not empirical cognitions.

It might at first be thought that the proposition 7 + 5 = 12
is a mere analytical judgment, following from the concept of
the sum of seven and five, according to the law of contra
diction. But on closer examination it appears that the con
cept of the sum of 7 + 5 contains merely their union in a
single number, without its being at all thought what the par
ticular number is that unites them. The concept of twelve
is by no means thought by merely thinking of the combina
tion of seven and five ; and analyse this possible sum as we
may, we shall not discover twelve in the concept. We must
go beyond these concepts, by calling to our aid the intuition
corresponding to one of them, say our five fingers, or five
[22] [visible] points (as Segner did in his arithmetic), and
we must add successively the units of the five given in the
intuition to the concept of seven.1 Hence our concept is

1 The reader will observe that to the concept of 7, the intuition of 5 is
gradually added ; it is not an addition of two intuitions. In the case
of 2 + 2 = 4, this latter may be the case, but most probably more
than 5 cannot be grasped in a single visible intuition. Accordingly 7 is
first made up of 5 + 2, and then the resulting concept used for further
processes. The system adopted in Roman figures (which is indeed almost
universal) illustrates the point exactly. Instead of writing six points
or strokes, we write VI, substituting the symbol V, perhaps a rude repre
sentation of an open hand, for the intuition IIIII. M.
II C

1 8 PROLEGOMENA TO METAPHYSIC [22-23

really amplified by the proposition 7 + 5 = 12, and we add
to the first a second, not thought in it. Arithmetical
judgments are therefore always synthetical, and the more
plainly according as we take larger numbers ; for in such
cases it is clear that, however closely we analyse our concepts
without calling intuition to our aid, we can never find the
sum by such mere dissection.

Just as little is any principle of geometry analytical.
That a straight line is the shortest between two points, is a
synthetical proposition. For my concept of straight contains
nothing of quantity, but only a quality. The attribute of
shortness is therefore altogether additional, and not obtain
able by any analysis of the concept. Intuition, which alone
makes the synthesis possible, must here also be brought in
to assist us.

[23] Some other principles, assumed by geometers, are
indeed actually analytical, and depend on the law of contra
diction ; but they only serve, as identical propositions, in
the chain of method, and not as l principles, ex. gr. a = a,
the whole is equal to itself, or a + b > a, the whole is greater
than its part. And yet even these, though they are
recognised as valid from mere concepts, are only admitted
in mathematics, because they can be represented in intui
tion.2 What usually makes us believe that the predicate
of such apodeictic judgments is already contained in our
concept, and that the judgment is therefore analytical, is
the ambiguity of the expression. For we ought to add in

1 Not 'from principles ; ' I think we should read als, not aus. M.

2 The remainder of this paragraph is very difficult, except we under
stand it, not of the analytical judgments just described, and to which
Kant's language would seem to refer it, but of the synthetical axioms
previously discussed. The whole passage, beginning from the analysis
of 7 + 5 = 12, is transcribed verbatim into the Second Edition of the
Kritik, without a single explanation. Cf. vol. i. p. 38. M.

23-25! PECULIARITIES OF METAPHYSICAL COGNITION 19

thought a certain predicate to a given concept, and this
necessity already attaches to the concepts. But the question
is not what we must join in thought to the given concept,
but what we actually think in it, though obscurely ; and so
it appears that the predicate belongs to these concepts
necessarily indeed, yet not as thought in [24] the
concept itself, but through the intervention of an intuition,
which must be added.

§ 3. Observations on the General Division of Judgments
into Analytical and Synthetical.

This division is indispensable, as concerns the Kritik of
the human understanding, and therefore deserves to be
called classical ; I know not whether it is elsewhere of
important use. And this is the reason why dogmatic
philosophers, who always seek the sources of metaphysical
judgments in Metaphysic itself, and not apart from it, in the
pure laws of reason generally — why these men altogether
neglected this apparently obvious distinction. So it was
that the celebrated Wolf, and his acute follower Baum-
garten, came to seek the proof of the principle of Sufficient
Reason, which is clearly synthetical, in the principle of
Contradiction. In Locke's Essay, on the contrary, I find
an indication of my division. For in the fourth book
(chap. iii. § 9, seq.\ after he has discussed the various
connexions of representations in judgments, and their
sources, one of which he makes identity and contradiction
(analytical judgments), and another the coexistence of
representations in a subject, he afterwards confesses (§ 10)
that our a priori knowledge of the latter is very narrow, and
almost nothing. But in his remarks on this species of
cognition, there is so [25] little of what is definite, and

20 PROLEGOMENA TO METAPHYSIC [25-26

reduced to rules,1 that we cannot wonder if no one, not
even Hume, was led to make investigations concerning this
sort of judgments. For such general and yet determinate
principles are not easily learned from other men, who have
had them obscurely in their minds. We must hit on them
first by our own reflection, then we find them elsewhere,
where we could not possibly have found them at first,
because the authors themselves did not know that such an
idea lay at the basis of their observations. Men who never
think independently have nevertheless the acuteness to
discover everything, after it has been once shown them, in
what was said long since, though no one ever saw it there
before.

[26] § 4. The General Question of the Prolegomena. — Is
Metaphysic at all possible ?

Were a Metaphysic, which could maintain its place as
a science, really in existence — if we could say, here is
Metaphysic, learn it, and it will convince you irresistibly and
irrevocably of its truth — then this question would be useless,
and there would only remain that other, which is rather a
test of our acuteness, than a proof of the existence of the

1 Unfortunately, Kant had not observed the really decisive passage
in Locke on the point. When discussing officially the various kinds of
agreement and disagreement among our ideas, he actually enumerates
the very classes, with the very examples, of Kant. First, judgments of
identity and diversity, sc. analytical, and his example is : Blue is not
yellow. Secondly, judgments of relation, an ill-chosen term, but
evidently the same as Kant's synthetical a priori, for his example is a
mathematical judgment, such as : The angles of a triangle are equal to
two right angles. Thirdly, judgments of coexistence (synthetical a
posteriori}, such as : Gold is fusible. Fourthly, judgments of existence
(afterwards distinguished by Kant as subjectively synthetical), such as :
God is. Can anything be more distinct than this ? See Locke's Essay,
book iv. chap. i. § 7, and cf. vol. i. p. 33. M.

26-27] PECULIARITIES OF METAPHYSICAL COGNITION 21

thing itself — I mean, the question how the science is possible^
and how the understanding comes to attain it. But the
human reason has not been so fortunate in this case. There
is no single book to which you can point as you do to
Euclid, and say : This is Metaphysic • here you may find the
noblest objects of this science, the knowledge of a highest
Being, and of a future existence, proved from principles of
pure reason. We can be shown indeed many judgments,
demonstrably certain, and never questioned ; but these are
all analytical, and rather concern the materials and the
scaffolding for Metaphysic, than the extension of knowledge,
which is our proper object in studying it (§ 2). Even
supposing you produce synthetical judgments (such as the
law of Sufficient Reason), which you could never have
proved, as you ought, from pure reason a priori, but which
we gladly concede, nevertheless, when they come to be
employed for your principal object, you lapse [27] into such
doubtful assertions, that in all ages one Metaphysic has
contradicted another, either in its assertions, or their proofs,
and thus has itself destroyed its own claim to lasting assent.
Nay the very attempts to set up such a science are the main
cause of the early appearance of scepticism, a mental
attitude in which reason treats itself with such violence
that it could never have arisen save from complete despair
of ever satisfying our most important aspirations. For long
before men began to question nature methodically, they
questioned isolated reason, which had to some extent been
exercised by means of ordinary experience; for reason is
ever present, while laws of nature must usually be sought
with labour. So Metaphysic floated to the surface, like
foam — like it also in this, that when what had been gathered
was dissolved, there immediately appeared a new supply on
the surface, to be ever eagerly collected by some, while

22 PROLEGOMENA TO METAPHYSTC [27-28

others, instead of seeking in the depths the cause of the
phenomenon, thought they showed their wisdom by ridiculing
the idle labour of their neighbours.

The essential and distinguishing feature of pure mathe
matical cognition among all other a priori cognitions is,
that it cannot at all proceed from concepts, but only by
means of the construction of concepts (Kritik, p. 435). As
therefore in its judgments it must proceed beyond the
concept to that which the corresponding intuition con
tains, these judg-[28]ments neither can, nor ought to,
arise analytically, by dissecting the concept, but are
all synthetical.

I cannot refrain from pointing out the disadvantages
resulting to philosophy from the neglect of this easy and
apparently insignificant observation. Hume indeed was
prompted (a task worthy of a philosopher) to cast his eye
over the whole field of a priori cognitions in which the
human understanding claims such mighty possessions. But
he incautiously severed from it a whole, and indeed its
most valuable, province, viz. pure mathematic. For he
thought its nature, or, so to speak, its constitution, depended
on totally different principles, namely, on the law of contra
diction alone ; and although he did not divide judgments
so formally or universally as I have here done, what he said
was equivalent to this : that mathematic contains only
analytical, but metaphysic synthetical a priori judgments.
In this he was greatly mistaken, and the mistake had a
decidedly injurious effect upon his whole conception
[system]. But for this, he would have extended his
question concerning the origin of our synthetical judgments
far beyond the metaphysical concept of Causality, and
included in it the possibility of mathematic a priori also, for
this latter he must have assumed to be equally synthetical

28-30] PECULIARITIES OF METAPHYSICAL COGNITION 23

And then he could not have based his metaphysical
judgments on mere experience without subjecting the
axioms of mathematic equally to experience, a thing which
[29] he was far too acute to do.1 The good company
into which metaphysic would thus have been brought,
would have saved it from the danger of a contemptuous ill-
treatment, for the thrust intended for it must have reached
mathematic, which was not and could not have been Hume's
intention. Thus that acute man would have been led into
considerations which must needs be similar to those that
now occupy us, but which would have gained inestimably
by his inimitably elegant style.

Proper metaphysical judgments are all synthetical. We
must distinguish judgments belonging to metaphysic from
properly metaphysical judgments. Many of the former are
analytical, but they only afford the means for metaphysical
judgments, which are the whole end of the science, and
which are always synthetical. For whatever concepts belong
to metaphysic (as, for example, substance), the judgments,
which arise from their mere analysis, belong also to meta
physic; as, for example, substance is that which only exists as
subject; and by means of several such analytical judgments,
we seek to approach the definition of the concept. But as
the analysis of pure concepts of the understanding, such as
are found in [30] metaphysic, does not proceed indifferently
from the dissection of any other (empirical) concept, not
belonging to metaphysic (such as : the air is an elastic
fluid, the elasticity of which is not removed by any known

1 Kant's confidence on this point is hardly justified. For in Hume's
Essays (which he declares to be his final declaration on Philosophy)
there are a good many hints that mathematics might be based on
experience. Cf. Essays, vol. ii. p. 468, note, etc. ; and in the Treatise it
is still more plain that he regarded experience as their ultimate ground.
Cf., however, vol. i. pp. 34 and 40, note. M.

24 PROLEGOMENA TO METAPHYSIC {30-31

degree of cold), it follows that the concept indeed, but not
the analytical judgment, is properly metaphysical. This
science has something peculiar in the production of its
a priori cognitions, which must therefore be distinguished
from the features it has in common with other rational
knowledge. Thus the judgment, "that all the substance in
things is permanent, is a synthetical and properly meta
physical judgment.

If the a priori principles, which constitute the materials
of metaphysic, have first been collected on fixed principles,
then their analysis is of great value ; it can also be taught
as a particular part (as a philosophia definitiva), containing
nothing but analytical judgments pertaining to metaphysic,
and separate from the synthetical, which constitute meta
physic proper. And indeed these analyses are not elsewhere
of much value, except in metaphysic, that is, as regards the
synthetical judgments, which are to be generated by these
previously analysed concepts.

The conclusion drawn in this section then is, that
metaphysic is properly concerned with synthetical pro
positions a priori^ and these alone constitute its end, for
which it indeed requires various analyses [31] of its
concepts, which are analytical judgments, but wherein the
procedure is not different from that in every other sort of
knowledge, in which we merely seek to render our concepts
distinct by analysis. But the generation of a priori cog
nition, as well of intuition as according to concepts, in fine
of synthetical propositions a priori in philosophical cognition,
this makes up the essential matter of Metaphysic.

Weary therefore as well of dogmatism, which teaches us
nothing, as of scepticism, which does not even promise us
anything, not even the quiet state of a contented ignorance —
excited [as we are] by the importance of a cognition of

31-32] PECULIARITIES OF METAPHYSICAL COGNITION 25

which we stand in need, and rendered suspicious by long
experience with regard to all knowledge which we believe
we possess, or which offers itself, under the title of pure
reason — there remains but one critical question to which the
answer must determine our future procedure : Is Metaphysic
at all possible 1 But this question must be answered not
by sceptical objections to the assertions of actual [systems
of] Metaphysic (for we do not as yet admit such a thing),
but from the conception, as yet only problematical ', of a
science of this sort.

In the Kritik of the Pure Reason I have treated this
question synthetically, by making inquiries into pure reason
itself, and endeavouring in this source to determine the
elements as well as the laws of its pure use according to
principles. The task is diffi-[32] cult, and requires a
resolute reader to penetrate by degrees into a system, based
on no data except the reason itself, and which therefore
seeks, without resting upon any fact, to unfold knowledge
from its original germs. Prolegomena on the contrary are
designed for exercises; they are intended rather to point
out what we have to do in order to realise [if possible] a
science, than to propound it. They must therefore rest
upon something already known as trustworthy, from which
we can set out with confidence, and ascend to sources as
yet unknown, the discovery of which will not only explain
to us what we knew, but exhibit a sphere of many cognitions
which all spring from the same sources. The method of
Prolegomena, especially of those designed as a preparation
for future metaphysic, is consequently analytical.

But it happens fortunately, that though we cannot assume
metaphysic to be an actual science, we can say with confi
dence that certain pure a priori synthetical cognitions, pure
Mathematic and pure Physic, are actual and given ; for

26 PROLEGOMENA TO METAPHYSIC [32-34

both contain propositions, which are thoroughly recognised
as apodeictically certain, partly by mere reason, partly by
general consent [arising] from experience, and yet as
independent of experience. . We have therefore some at
least uncontested synthetical knowledge a priori, and need
not ask if it be possible (for it is actual), but possible, in
order that we may deduce from the prin- [33] ciple which
makes the given cognitions possible the possibility of all
the rest.

The General Problem : How is Cognition from Pure
Reason possible ?

§ 5. We have already seen the vital distinction between
analytical and synthetical judgments. The possibility of
analytical propositions was easily comprehended, being
entirely founded on the law of Contradiction. The possi
bility of synthetical a posteriori judgments, of those which
are gathered from experience, likewise requires no particular
explanation ; for experience is nothing but a continual
synthesis of perceptions. There remain therefore only
synthetical propositions a priori, of which the possibility
must be sought or investigated, because they must depend
upon other principles than that of contradiction.

But we have no right to seek the possibility of such
propositions here, that is, to inquire whether they are
possible. For there are enough of them actually given
with undoubted certainty, and as our present method is
analytical, we shall start from the assertion, that such
synthetical but pure cognition of the reason actually exists ;
but we must then inquire into the ground of this possibility,
and ask, how this cognition is possible, in order that we
may [34] from the principles of its possibility be enabled to

34-351 PECULIARITIES OF METAPHYSICAL COGNITION 27

determine the conditions of its use, its sphere and its
bounds. The proper problem upon which all depends,
when expressed with scholastic precision, is therefore :

How are Synthetic Propositions a priori possible ?

For the sake of popularity I have above expressed this
problem somewhat differently, as an inquiry after knowledge
from pure reason, and this I could do for once without
detriment to the desired view [Einsicht], because, as we
have only to do here with metaphysic and its sources, the
reader will, I hope, after the foregoing remarks, keep in
mind that when we speak of knowledge from pure reason,
we do not mean analytical, but always synthetical cog
nition.1

[35] Upon the solution of this problem the standing or
the falling of Metaphysic and consequently its existence
entirely depend. Let any one make assertions ever so
plausible with regard to it, — let him pile conclusions upon
conclusions till they almost smother us, — if he has not been
previously able to answer this question satisfactorily, I have
a right to say : this is all vain groundless philosophy and

1 As knowledge gradually advances, certain expressions now classical,
which have been used since the infancy of science, cannot but be found
insufficient and unsuitable, and there cannot but be some danger of
confusing a newer and more appropriate use with the older. The
analytical method, so far as it is opposed to the synthetical, is very
distinct from a complex of analytical propositions : it signifies only that
we set out from what is sought, as if it were given, and ascend to the
only conditions under which it is possible. In this method we often use
nothing but synthetical propositions, as in mathematical analysis, and it
were better to term it the regressive method, in contradistinction to the
synthetic or progressive. A principal part of Logic too is distinguished
by the name of Analytic, which here signifies the logic of truth (in
contrast to Dialectic), without considering whether the cognitions
belonging to it are analytical or synthetical.

28 PROLEGOMENA TO METAPHYSIC [35-36

false wisdom. You speak through pure reason, and profess,
as it were, to create cognitions a priori by not only dis
secting given concepts, but also by asserting connexions
which do not rest upon the principle of contradiction, and
which you profess to perceive quite independently of all ex
perience ; how do you attain this, and how will you justify your
self in such pretensions ? An appeal to the consent of the
common sense of mankind cannot be allowed ; for that is a
witness whose reputation depends only upon public rumour,

Quodcunque ostendis mihi sic, incredulus odi. '

Indispensable, however, as it is to answer this question,
it is equally difficult to do so ; and though the principal
reason that this answer was not attempted long ago is, that
the possibility of such a question [36] never occurred to
anybody, there is yet another reason. A satisfactory answer
to this single question requires a much more constant, pro
found, and laborious reflection, than the most diffuse work
on Metaphysic, which on its first appearance promised
immortality to its author. And every intelligent reader,
when he carefully reflects what this problem requires, must
at first be struck with its difficulty, and would regard it as
insoluble and even impossible, did there not actually exist
pure synthetical cognitions a priori. This actually happened
to David Hume, though he did not represent to himself the
question at all so universally as is done here, and as must
be done if the answer is to be decisive for all Metaphysic.
For how is it possible, says that acute man, that when a
concept is given me, I can go beyond it and connect with
it another, which is not contained in it, and in such a
manner as if the latter necessarily belonged to the former ?
Nothing but experience can furnish us with connexions of
that sort (this was his inference from that difficulty, which

36-38] PECULIARITIES OF METAPHYSICAL COGNITION 29

he held an impossibility), and all that supposed necessity, or,
what is the same. thing, all cognition a priori (held to be
such), is nothing but a long habit of finding something true,
and hence of holding subjective necessity to be objective.

If the reader should complain of the difficulty and the
labour which I occasion him in the solution of this problem,
let him endeavour to do it himself [37] in an easier way.
Perhaps he will then acknowledge the obligation due to him
who has undertaken a work of so profound research, and
will rather be surprised at the facility with which, consider
ing the nature of the thing, the solution has been attained.
Yet it has cost a labour of many years to solve this problem
in its whole universality (in the mathematical sense, that, is,
sufficient for all cases), and finally to exhibit it in the
analytical form, as the reader finds it here.

All metaphysicians are therefore solemnly and legally sus
pended from their occupations till they shall have answered
in a satisfactory manner the question, How are synthetic
cognitions a priori possible ? For the answer contains the
only credentials which they must show when they have any
thing to bring us in the name of pure reason. But if they
do not possess these credentials, they can expect nothing
else than to be dismissed without further inquiry by reason
able people, who have already been so often deceived.

If they on the other hand desire to carry on their busi
ness not as a science, but as an art of persuasion wholesome
and suited to the general common sense of man, they cannot
in justice be prevented. They will then speak the modest
language of a rational faith, they will grant that they are not
allowed even to conjecture, far less to know, anything which
lies beyond the bounds of all possible experience, but only
[38] to assume something (not for speculative use, which
they must abandon, but for practical only) that is possible

30 PROLEGOMENA TO METAPHYSIC [38-39

and even indispensable for the guidance of the understanding
and of the will in life. In this manner only can they bear
the title of useful and of wise men, and the more so in pro
portion as they renounce that of metaphysicians ; for these
will be speculative philosophers, and as, when judgments a
priori are in question, poor probabilities cannot be admitted
(for what is pretended to be known a priori is thereby
announced as necessary), such men cannot be permitted to
play with conjectures, but their assertions must be either
science, or worth nothing at all.

It may be said, that all transcendental philosophy, which
necessarily precedes all Metaphysic, is nothing but the
complete solution of the problem here propounded, in
systematical order and completeness. Hitherto we have
accordingly never had any transcendental philosophy ; for
what goes by its name is properly a part of Metaphysic ;
whereas the former science is intended first to constitute the
possibility of this latter, and must therefore precede all
Metaphysic. And it is not surprising that when a whole
science, deprived of all help from other sciences, and conse
quently in itself quite new, is required to answer a single
question sufficiently, we should find this answer combined
with trouble and difficulty, nay even with obscurity.

[39] As we now proceed to this solution, and according
to the analytical method, in which we presuppose, that such
cognitions from pure reason actually exist, we can only
appeal to two sciences of theoretical cognition (as such only
is under consideration here), pure mathematic and the pure
science of nature (physic). For none but these can exhibit
objects intuitively to us, and consequently (if there should
occur in them a cognition a priori] can show the truth or
harmony of the cognition with the object in concrete, that is,
its actuality, from which we could then proceed to the

39-40] PECULIARITIES OF METAPHYSICAL COGNITION 31

ground of its possibility by analytic procedure. This
method facilitates our labour greatly, in which the universal
considerations are not only applied to facts, but even set out
from them, instead of which they must in synthetic pro
cedure be entirely derived in abstracto from concepts.

But, in order to rise from these actual and at the same
time well grounded pure cognitions a priori to a possible
cognition (which we are seeking), or to Metaphysic as a
science, it is necessary for us to comprehend that which
occasions it, I mean the mere natural, though in spite of its
truth not unsuspected, cognition a priori which lies at the
basis of that science, the elaboration of which without any
critical investigation of its possibility is commonly called
metaphysic, — in a word, we must comprehend the natural
predisposition to such a science under our chief inquiry,
and thus will the general transcendental [40] problem,
divided into four other questions, be gradually answered :

1. How is pure mathematic possible ?

2. How is pure physic [science of nature] possible ?

3. How is metaphysic in general possible ?

4. How is metaphysic as a science possible ?

It may be seen that the solution of these problems,
though chiefly designed to exhibit the essential matter of
the Kritik, has yet something peculiar, which deserves atten
tion in itself. This is the seeking the sources of given
sciences in the reason itself, so that its faculty of knowing
something a priori may be investigated and measured by
means of the act itself. By this procedure these sciences
themselves gain, if not with regard to their content, yet as
to their right use, and while they throw light on the higher
question concerning their common origin, at the same time
give occasion better to explain their individual nature.

[41] FIRST PART OF THE GENERAL TRAN
SCENDENTAL PROBLEM

Hoiv is Pure Mathematic possible ?

§ 6. HERE is a great and established cognition, which em
braces even now a wonderful sphere, and bespeaks here
after an unbounded extension, which carries with it
thoroughly apodeictical certainty, that is, absolute necessity,
which therefore rests upon no empirical grounds, and
consequently is a pure product of reason, and moreover is
thoroughly synthetical. ' How then is it possible for human
reason to bring to pass a cognition of this nature entirely
a priori ? ' Does not this faculty, as it neither is nor can
be based upon experience, presuppose some ground of
cognition a priori, which lies deeply hidden, but which
might reveal itself by these' its effects, if their first begin
nings were but diligently investigated ?

§ 7. But we find all mathematical cognition having this
peculiarity, that it must previously exhibit its concept in
intuition and indeed a priori, therefore in an intuition which
is not empirical, but pure. Without this process Mathe
matic cannot take a single [42] step; hence its judgments
are always intuitive ; whereas philosophy must be satisfied
with discursive judgments from mere concepts, and though it
may illustrate its doctrines by intuition, can never derive them

42-43] HOW IS PURE MATHEMATIC POSSIBLE? 33

from it. This observation on the nature of Mathematic
gives us a clue to the first and highest condition of its
possibility, which is, that some pure intuition must form its
basis, in which all its concepts can be exhibited or con
structed, in concrete and yet a priori. If we can find out
this pure intuition and its possibility, we may thence
easily explain how synthetical propositions a priori are
possible in pure mathematic, and consequently how this
science itself is possible. Empirical intuition enables us
without difficulty to enlarge the concept which we frame of
an object of intuition, by new predicates, which intuition
itself presents synthetically in experience. Pure intuition
does so likewise, only with this difference, that in the latter
case the synthetical judgment is a priori certain and
apodeictical, in the former, only a posteriori and empirically
certain ; because this latter contains only what occurs in
contingent empirical intuition, but the former, what must
be met in pure intuition necessarily, for the predicate is
inseparably conjoined as intuition a priori with the concept
before all experience or individual perception.

§8. But with this step our perplexity seems rather to
increase than to lessen. For the question [43] now is, How
is it possible to intuite anything a priori ? An intuition is
such a representation as immediately depends upon the
presence of the object. Hence it seems impossible origin
ally to intuite a priori, because intuition would in that
event take place without either a former or a present object
to refer to, and by consequence could not be intuition.
Concepts indeed are such, that we can easily form some of
them a priori (namely, those which contain nothing but the
thinking an object in general), without finding ourselves in
an immediate relation to the object. Such are, for instance,
the concepts of Quantity, of Cause, etc. But even these
H p

34 PROLEGOMENA TO METAPHYSIC [43-44

require, in order to give them a signification, a certain
concrete use — that is, an application to some intuition, by
which an object of them is given us. But how can the
intuition of the object precede the object itself?

§ 9. Were intuition of such nature as to represent things
as they are in themselves, intuition could not take place a
priori, but must be always empirical. For I can only know
what is contained in the object in itself when it is present
and given to me. It is indeed even then incomprehensible
how the intuition of a present thing should make me know
this thing as it is in itself, as its properties cannot migrate into
my faculty of representation ; but even granting this possi
bility, an intuition of that sort would not take place a priori,
that is, before the object were presented to me ; for without
this latter [44] fact no ground of relation between my
representation and the object can be imagined: it must
then depend upon direct inspiration [Eingebung]. It is
therefore only possible in one way for my intuition to
anticipate the actuality of the object, and to be cognition
a priori : if it (the intuition) contains nothing but the form of
the sensibility, which precedes in me all the actual impressions
through which I am affected by objects. For I can know a
priori, that objects of sense can only be intuited according
to this form of the sensuous intuition. Hence it follows :
that propositions, which concern this form of sensuous
intuition only, are possible and valid for objects of the
senses ; as also, conversely, that intuitions which are possible
a priori can never concern any other things than objects
of our senses.

§ 10. It is then only the form of sensuous intuition by
which we can intuite things a priori, but by which we can
know objects only as they appear to us (to our senses), not
|as they are in themselves ; and this assumption is absolutely

44-46] HOW IS PURE MATHEMATIC POSSIBLE ? 35

necessary if synthetical propositions a priori be granted as
possible, or if, in case they actually occur, their possibility is
to be comprehended and determined beforehand.

But Space and Time are the intuitions which pure
Mathematic lays at the foundation of all its cognitions, and
of the judgments which appear at once demonstrable and
necessary ; for Mathematic must [45] first exhibit all its con
cepts in intuition, and pure Mathematic in pure intuition,
that is, it must construct them ; otherwise (as it cannot
proceed analytically, by dissection of concepts, but synthetic
ally) it is impossible in this science to take a single step.
For if pure intuition be wanting, there is nothing in which
the matter for synthetical judgments a priori can be given.
Geometry is based upon the pure intuition of space.
Arithmetic accomplishes its concept of number by the
successive addition of unities in time ; and pure Mechanic
especially cannot attain its concepts of motion without em
ploying the representation of time.1 Both representations,
however, are only intuitions ; for if we omit from the empir
ical intuitions of bodies and their alterations (motion) every
thing empirical, or belonging to sensation, space and time"
still remain, which are therefore pure intuitions that lie a
priori at the basis of the empirical. Hence they can never
be omitted, but at the same time, by their [46] being pure in-/
tuitions a priori, they prove that they are mere forms of our

1 The form of this statement, which makes an admission nowhere
supported in the Kritik, is peculiar. I see in it a lurking doubt in
Kant's mind whether Arithmetic may not be derived from Time, as all
' his commentators believed. He feels sure about Mechanic. The
reader will also note that he speaks as if only the concept of number
generally were so derived. This is certainly true of the schema of
quantity, and may also be asserted of all very large numbers, which we
cannot properly imagine, except as requiring unfinished acts of addition.
Cf. vol. i. p. 52. M.

36 PROLEGOMENA TO METAPHYSIC [46-47

sensibility, which must precede all empirical intuition, or
perception of actual objects, and conformably to which
objects can be known a priori, but only as they appear
to us.

§11. The problem of the present section is therefore
solved. Pure mathematic, as synthetical cognition a priori,
is only possible by referring to no other objects than those
of the senses. At the basis of their empirical intuition lies
a pure intuition (of space and of time) a priori. This is
possible, because the latter intuition is nothing but the mere
form of the sensitive faculty, which precedes the actual
appearance of the objects, in that it in fact makes them
possible. Yet this faculty of intuiting a priori affects not
the matter of the phenomenon (that is, the sensation in it,
for this constitutes that which is empirical), but its form,
viz. space and time. Should any man venture to doubt
that these are determinations adhering not to things in
themselves, but to their relation to our sensibility, I should
be glad to know how it can be possible to know a priori
(and of course before all acquaintance with, or presentation
of, things), how their intuition must be constituted ; which
however is here the case with space and time. But this is
quite comprehensible as soon as both count for nothing
more than formal conditions of our sensibility, while the
objects count merely as phenomena; [47] for then the
jorm_of the phenomenon, that is, the pure intuition, can
by all means be represented us proceeding from ourselves,
that is, a priori.

§ 1 2. In order to add something by way of illustration and
confirmation, we need only attend to the ordinary and neces
sary procedure of geometers. All proofs of the complete
equality l of two given figures (where the one can be com-

1 As distinguished from equivalence, or merely equality of area. M.

47-4§] HOW IS PURE MATIIEMATIC POSSIBLE ? 37

pletely substituted for the other) come ultimately to super
position, which is evidently nothing else than a synthetical
proposition resting upon immediate intuition, and this intui
tion must be given pure, or a priori, otherwise the proposition
could not rank as apodeictically certain, but would have em
pirical certainty only. It could only be said that it is always
remarked so, and holds as far as our perception reaches.
That complete space (which is itself no longer the boundary
of another space) has three dimensions, and that space in
general cannot have more, is based on the proposition that
not more than three lines can intersect at right angles in
one point ; but this proposition cannot by any means be
shown from concepts, but rests immediately on pure and a
priori intuition, because it is apodeictically certain. That we
can require a line to be drawn to infinity (in indefinituni)^
a series [48] of changes to be continued (for example, spaces
passed ^through by motion) in indefinitum, presupposes a
representation of space and time, which can only attach to
intuition, namely, so far as it in itself is bounded by nothing,
for from concepts it could never be inferred. Consequently
Mathematic is actually built upon pure intuitions, which make
its synthetical and apodeictically valid propositions possible,
and hence our transcendental deduction of the notions of
space and of time explains at the same time the possibility
of pure mathematic, which may be conceded, but by no
means explained, without some such deduction, and without
our assuming ' that everything which can be given to our
senses (to the external sense in space, the internal in time)
is intuited by us as it appears to us, not as it is in itself.'

1 This identification of unendlich with indefinitum goes far to corro
borate my rendering of the objectionable phrase in the Aesthetic, which
speaks of space as an infinite (unendlich) given quantity. Cf. vol. i. p.
50, note. M.

38 PROLEGOMENA TO METAPHYSIC [48-49

§ 1 3. Those who cannot yet shake off the notion of space
and time being actual qualities that inhere in things in them
selves, may exercise their acumen on the following paradox.
When they have in vain attempted its solution, and are free
from prejudices at least for a few moments, they will suspect
that the degradation of space and of time to mere forms of
our sensuous intuition may perhaps be well founded.

When two things are quite similar in all the points, which
can be known of each separately (in all the determinations
pertaining to quantity and to [49] quality), it must follow,
that the one can in all cases and relations be put in the
place of the other, without this substitution occasioning the
least perceptible difference. This in fact is the case with
plane figures in geometry ; but various spherical figures
exhibit, notwithstanding this complete internal agreement,
such a [limited] one in their external relation, that the one
figure cannot possibly be put in the place of the other ; for
instance, two spherical triangles on opposite hemispheres,
which have an arc of the equator as their common base,
may be quite equal, both as regards sides and angles, so
that nothing is to be found in the simple and complete
description of the one, that is not equally in the description
of the other, and yet the one cannot be put in the place of
the other (upon the opposite hemisphere). Here is then an
internal difference between the two triangles, which difference
no understanding can describe as internal, and which only
manifests itself by external relations in space. But I shall
give more obvious examples, taken from common life.

What can be more similar in every respect to my hand
and to my ear, or in every part more alike, than their images
in a mirror ? And yet I cannot put such a hand as is seen
in the glass in the place of its archetype ; for if this is a
right, that in the glass is a left hand, and the image or re-

49-51] HOW IS PURE MATHEMATIC POSSIBLE? 39

flection of the right ear is a left one that never can supply
the place of the other. Here there are no internal
differences [50] which any understanding could perceive by
thought alone ; and yet the differences are internal as far as
the senses teach, for the left hand cannot be enclosed in
the same bounds as the right, notwithstanding the complete
equality and similarity of both (they are not congruent) ;
the glove of one hand cannot be used for the other. What
is the solution ? Those objects are not representations of
things as they are in themselves, and as the pure under
standing would cognise them, but sensuous intuitions, that
is, phenomena, the possibility of which rests upon the rela
tion of certain things unknown in themselves to something
else, viz. to our sensibility. Space is the form of the ex
ternal intuition of this sensibility, and the internal deter
mination of every [limited] space is only possible by the
determination of its external relation to all space, of which
it is a part (in other words, by its relation to the external
sense) ; that is, the part is only possible through the whole,
which is never the case with things in themselves, as objects
of the mere understanding, but with phenomena only. And
hence we cannot render the difference between similar and
equal but incongruous things (for instance, spirals winding
opposite ways1) intelligible by any concept, but only by the
relation to the right and the left hand, which relates im
mediately to intuition.

[51] REMARK I.

Pure Mathematic, and especially pure geometry, can
only have objective reality on condition of its referring to

1 Not ' snails rolled up contrary to all sense,' as Mr. Richardson
has it !

4o PROLEGOMENA TO METAPHYSIC [51-52

objects of sense, in regard to which the principle holds
good, that our sensuous representation is a representation
not of things in themselves, but of the way in which they
appear to us. Hence it follows, that the propositions of
geometry are not the determinations of a mere creation of
our poetic fancy, which therefore cannot be referred with
certainty to actual objects ; but rather that they are neces
sarily valid of space, and consequently of all that may be
found in it, because space is nothing else than the form of all
external phenomena, in which [form] alone objects of sense
can be given. Sensibility (of which the form is the basis
of geometry) is that upon which the possibility of external
phenomena rests ; these therefore can never contain any
thing but what geometry prescribes to them. It would be
quite otherwise if the senses were so constituted as to
represent objects as they are in themselves. For then it
would not by any means follow from the representation of
space, which the geometer makes his a priori foundation,
with all its properties, that this space, together with what is
thence inferred, must be so in nature. The space of the
geometer would be considered a mere fiction, and no
objective validity ascribed to it, because we cannot see how
things [52] must of necessity agree with an image of them,
which we make spontaneously and previous to our per
ception of them. But if this image, or rather this formal
intuition, is the essential property of our sensibility, by
means of which alone objects are given to us, and if this
sensibility represents not things in themselves, but phe
nomena — then it is very easy to comprehend, and at the
same time to prove indisputably, that all the external
objects of our world of sense must necessarily accord
strictly with the propositions of geometry; because the
sensibility by means of its form of external intuition (in

52-53] HOW IS PURE MATIIEMATIC POSSIBLE? 41

other words, by space, with which the geometer is occu
pied), first of all makes those objects possible as mere
appearances. It will always remain a remarkable feature
in the history of philosophy, that there was once a time,
when even mathematicians, who were philosophers too,
began to doubt, not of the accuracy of their geometrical
propositions so far as they concerned space, but of the
objective validity and the applicability of this concept itself,
and of all its determinations, to nature. They were appre
hensive that a line in nature might consist of physical
points, and consequently that true space in the object might
consist of simple parts, though the space which the geo
meter has in his mind cannot be such. They did not
recognise that this mental space makes the physical space,
that is, the extension of matter, even possible ; that this
pure space is not at all a [53] quality of things in them
selves, but a form of our sensuous faculty of representation ;
and that all objects in space are mere phenomena, that
is, not things in themselves but representations of our
sensuous intuition. Space, therefore, as the' geometer
conceives it, is strictly the form of sensuous intuition which
we find a priori in us, and contains the ground of the
possibility of all external phenomena (as to their form), so
that these must necessarily and accurately agree with the
propositions of the geometer, which he draws not from any
imaginary concept, but from the subjective basis of all
external phenomena, which is the sensibility itself. In this
and no other way can Geometry be secured (as to the
undoubted objective reality of its propositions) from all the
juggling of shallow Metaphysic, however surprising it may
seem to this science, because it has not reverted to the
sources of its concepts.

42 PROLEGOMENA TO METAPHYSIC [53-54

REMARK II.

Whatever is given us as object, must be given us in
intuition. All our intuition however takes place by means
of the senses only ; the understanding intuites nothing, but
only reflects.1 And as we have [54] just shown that the
senses never and in no manner enable us to know things in
themselves, but only their phenomena, which are mere
representations of the sensibility, we conclude that 'all
bodies, together with the space in which they are, must be
considered nothing but mere representations in us, and exist
nowhere but in our thoughts.' You will say : Is not this
manifest idealism ?

Idealism consists in the assertion, that there are none
but thinking beings, all other things, which we think are
perceived in intuition, being nothing but representations in
the thinking beings, to which no object external to them
corresponds in fact. Whereas I say, that things as objects
of our senses existing outside us are given, but we know
nothing of what they may be in themselves, knowing only
their phenomena, that is, the representations which they
cause in us by affecting our senses. Consequently I grant
by all means that there are bodies without us, that is, things
which, though quite unknown to us as to what they are
in themselves, we yet know by the representations which
their influence on our sensibility procures us, and which we
call bodies, a term signifying merely the appearance of the
thing which is unknown to us, but not therefore less

1 This, and a dozen other such passages, should have kept Mr.
Lewes (Hist, of Phil. ii. p. 515) from putting the vaguely-worded
question : « Did Kant mean that man has intuitive Reason ? ' and still
more from answering it in exactly the reverse way to what Kant would
have done. M.

54-56] HOW IS PURE MATHEMATIC POSSIBLE ? 43

actual.1 Can this be termed idealism ? It is the very
contrary.

[55] All this had been generally assumed and granted
long before Locke's time, and still more generally ever
since — that, without detriment to the actual existence of
external things, many of their predicates may be said to
belong not to the things in themselves, but to their
phenomena, and to have no proper existence outside our
representation. Heat, colour, and taste, for instance, are
of this kind. But that I should go farther, and rank as
mere phenomena, for weighty reasons, the remaining quali
ties of bodies also, which are called primary, such as
extension, place, and in general space, with all which
belongs to it (impenetrability or materiality, figure, etc.) —
against this proceeding no one can contend with any reason
that it is inadmissible. As little as the man who admits
colours not to be properties of the object in itself, but only
modifications of the sense of seeing, can on that account
be named an idealist, so little can my system be named
idealistic, merely because I find that more, nay, that all the
properties which constitute the intuition of a body belong
merely to its phenomenon ; for the existence of the thing
that appears is thereby not destroyed, as in true idealism,
but it is only shown, that we cannot possibly know it by
the senses as it is in itself.

[56] I should be glad to know what my assertions must
be in order to avoid all idealism. I suppose I must say,
not only that the representation of space is perfectly con
formable to the relation which our sensibility has to objects

1 This statement is more explicit than anything in the Kritik, and
settles the question as to Kant's supposed idealism. Had his First
Edition really differed from this exposition, he would never have sug
gested to his readers a comparison with the Second. M.

44 PROLEGOMENA TO METAPHYSIC [56-57

— for that I have said — but also that it is quite similar to
them ; an assertion in which I can find as little meaning as
if I said that the sensation of red has a similarity to the
property of vermilion, which excites this sensation in me.

REMARK III.

Hence we may at once obviate an easily foreseen but
worthless objection, ' that by admitting the ideality of space
and of time the whole sensible world would be turned
into mere illusion.' For men had at first spoiled all
philosophical insight into the nature of sensuous cognition,
by making the sensibility merely a confused mode of
representation, according to which we still know things as
they are, but without being able to bring everything in this
our representation to a clear consciousness ; whereas we
had proved, that sensibility consists not in this logical
distinction of clearness and obscurity, but in the genetical
one of the origin of cognition itself. For sensuous cogni
tion represents things not at all as they are, but only the
mode in which they affect our senses, and consequently by
it phenomena only and not things themselves are [57] given
to the understanding for reflection. After this necessary cor
rection, an objection is mooted arising from an unpardon
able and almost intentional misconception, as if my system
turned all the things of the world of sense into mere illusion.

When an appearance is given us, we are still quite free
as to our judgment on the matter. The phenomenon
depends upon the senses, but the judgment upon the under
standing, and the only question is, whether in the determina
tion of the object there is truth or not. But the difference
between truth and dreaming is not ascertained by the nature
of the representations, which are referred to objects (for

57-58] HOW IS PURE MATHEMATIC POSSIBLE ? 45

they are the same in both cases), but by their connexion
according to those rules, which determine the coherence of
the representations in the concept of an object, and by
ascertaining whether they can subsist together in experience
or not. And it is not the fault of the phenomena if our
cognition takes illusion for truth, that is, if the intuition, by
which an object is given us, is considered a concept of the
thing or of its existence also, which the understanding can
only think. The senses represent to us the paths of the
planets as now forward, now backward, and herein is neither
falsehood nor truth, because as long as we hold this path to
be nothing but appearance, we do not judge of the objective
nature of their motion. But as a false judgment may easily
arise when the understanding does not carefully guard [58]
against this subjective mode of representation being con
sidered objective, we say they appear to move backward ; it
is not the senses however which are charged with the
illusion, but the understanding, whose province alone it is
to give an objective judgment on the phenomenon.

Thus, even if we did not at all reflect on the origin of our
representations, and [merely] connect our intuitions of sense
(whatever they may contain), in space and in time, according
to the rules of the coherence of all cognition in experience,
[still] illusion or truth may arise according as we are
negligent or careful ; it is merely a question of the use of
sensuous representations in the understanding, and not of
their origin. Again — when I consider all the representa
tions of the senses, together with their form, space and time,
to be nothing but phenomena, and space and time to be
a mere form of the sensibility, which is not to be met with
in objects out of it, and when I make use of these repre
sentations in reference to possible experience only — there is
nothing therein that can lead to error, nor is there any

46 PROLEGOMENA TO METAPHYSIC [58-60

illusion implied in my holding them mere phenomena ; for
they can notwithstanding cohere rightly according to rules
of truth in experience. Thus all the propositions of
geometry hold good of space as well as of all the objects of
the senses, consequently of all possible experience, whether
I consider space as a mere form of the sensibility, or as
something [59] cleaving to the things themselves. It is
only in the former case that I can comprehend how it is
possible to know these propositions of all the objects of ex
ternal intuition a priori ; everything else which regards all
possible experience remains just as if I had not seceded
from the common opinion.

But if I venture to go beyond all possible experience
with my notions of space and time, which I cannot avoid
doing if I proclaim them qualities which adhere to things in
themselves (for what can prevent my letting them hold
good of the same things, however my senses might be
changed, and whether they were suited to them or not ?),
then a grave error resting upon an illusion may arise. For I
proclaim to be universally valid what is merely a subjective
condition of the intuition of things and sure for all objects
of sense, but therefore only valid for all possible experience ;
since in doing so, I refer this condition to things in them
selves, and do not limit it to the conditions of experience.

My theory of the ideality of space and of time, therefore,
so far from reducing the whole sensible world to mere
illusion, is rather the only means of securing the application
of one of the most important cognitions (that which mathe-
matic propounds a priori] to actual objects, and of pre
venting its being regarded mere illusion. For without this
observation it would be quite impossible to make out
whether the intuitions of space and time, which we borrow
from [60] no experience, and which yet lie in our repre-

60-61] HOW IS PURE MATHEMATIC POSSIBLE ? 47

sentation a priori, are not mere chimeras of our brain, to
which no object whatever corresponds, at least adequately,
and consequently, whether geometry itself is not a mere
illusion, whereas we have been able to show its unquestion
able validity with regard to all the objects of the sensible
world because they are mere phenomena.

Secondly : These my principles, because they make
phenomena of the representations of the senses, are so far
from turning the truth of experience into mere illusion, that
they are rather the only means of preventing the transcend
ental illusion, by which Metaphysic has hitherto been
deceived, and led to the childish endeavour of catching at
bubbles, while phenomena, which are mere representations,
were taken for things in themselves — an error which gave
occasion to the remarkable Antinomy of Reason that I shall
mention by and by, and which is destroyed by the single
observation, that phenomenon, as long as it is used in ex
perience, produces truth, but the moment it transgresses the
bounds of experience, and consequently becomes transcend
ent, produces nothing but illusion.

As I therefore leave to things as we obtain them by the
senses their actuality, and only limit our sensuous intuition
of these things to this, that they represent in no respect,
not even in the pure intuitions of space and of time, any
thing more than [61] mere appearances of those things, but
never their constitution in themselves, this is not a thorough
going illusion invented for nature by me. My protesta
tion too against all charges of idealism is so valid and clear
as even to seem superfluous, were there not incompetent
judges, who, while they would have an old name for every
deviation from their perverse though common opinion, and
never judge of the spirit of philosophic nomenclature, but
cling to the letter only, are ready to put their own conceits

48 PROLEGOMENA TO METAPHYSIC [61-62

in the place of well-determined notions, and thereby deform
and distort them. For my having given this my theory the
name of transcendental idealism, can authorise no one to
confound it with the empirical idealism of Descartes.
(Indeed his was only an insoluble problem, owing to which
he thought every one at liberty to deny the existence of the
corporeal world, as it never could be proved satisfactorily.)
Nor [does it justify a confusion] with the mystical and
visionary idealism of Berkeley, against which and other
similar chimeras our Kritik rather contains the proper anti
dote. For my idealism concerns not the existence of things
(the doubting of which however constitutes idealism in the
ordinary sense), since it never came into my head to doubt
them,1 but it concerns the sensuous [62] representation of
things, to which space and time especially belong. Of these,
consequently of all phenomena in general, I have only shown,
that they are neither things (nor determinations belonging
to things in themselves), but mere species of representation.
But the word 'transcendental,' which with me means a
reference of our cognition not to things, but only to the
cognitive faculty ', was meant to obviate this misconception.
Yet rather than give further occasion to it by this word, I
now retract it, and desire this idealism of mine to be called
critical. But if it be really an objectionable idealism to
convert actual things (not phenomena) into mere representa
tions, by what denomination shall we distinguish that
idealism which conversely makes things of mere representa
tions? It may, I think, be called dreaming idealism, in
contradistinction to the former, which may be called
visionary, both of which are to be obviated by my transcend
ental, or, better, critical idealism.

1 I recommend the school of Kuno Fischer to consider this plain
utterance. M.

[63] SECOND PART OF THE GENERAL TRAN
SCENDENTAL PROBLEM

Hoiv is the Pure Science of Nature \Physic\ possible ?

§ 14. NATURE is the existence of things, so far as it is
determined according to universal laws. Should nature
signify the existence of things in themselves, we could never
cognise nature either a priori or a posteriori. Not a priori,
for how can we know what belongs to things in themselves,
since this never can be done by the dissection of our con
cepts (analytical judgments) ? For we do not want to know
what is contained in our concept of a thing (for this [content]
belongs to its logical being), but what is in the actuality of
the thing superadded to our concept, and by what the thing
itself is determined in its existence outside the concept.
Our understanding, and the conditions on which alone it
can connect the determinations of things in their existence,
do not prescribe any rule to things themselves ; these do
not conform to our understanding, but it must conform
itself to them ; they must therefore be first given us in
order to gather these determinations from them, wherefore
they would not be cognised a priori.

[64] A cognition of the nature of things in themselves a
posteriori would be equally impossible. For, if experience
is to teach us laws, to which the existence of things is

II E

50 PROLEGOMENA TO METAPIIYSIC [64-65

subject, these laws, if they regard things in themselves, must
belong to them of necessity even outside our experience.
But experience teaches us what exists and how it exists, but
never that it must necessarily exist so and not otherwise.
Experience therefore can never teach us the nature of things
in themselves.

§ 1 5. We nevertheless actually possess a pure science of
nature in which are propounded, a priori and with all the
necessity requisite to apodeictical propositions, laws to which
nature is subject. I need only call to witness that pro
paedeutic of Physic which, under the title of the universal
Science of Nature, precedes all Physic (which is founded
upon empirical principles). In it we have Mathematic
applied to phenomena, and also merely discursive principles
(or those derived from concepts), which constitute the philo
sophical part of the pure cognition of nature. But there
are several things in it, which are not quite pure and inde
pendent of empirical sources : such as the concept of motion,
that of impenetrability (upon which the empirical concept of
matter rests), that of inertia, and many others, which prevent
its being called a perfectly pure science of nature. Besides,
it only refers to objects of the external sense, and therefore
does not give an example [65] of a universal science of nature,
in the strict sense, for such a science must reduce nature in
general, whether it regards the object of the external or that
of the internal sense (the object of Physic as well as
Psychology), to universal laws. But among the principles
of this universal Physic there are a few which actually have
the required universality ; for instance, the propositions that
substance is permanent, and that every event is always
previously determined by a cause according to constant laws,
etc. These are actually universal laws of nature, which
subsist completely a priori. There is then in fact a pure

65-66] HOW IS PURE SCIENCE OE NATURE POSSIBLE ? 51

science of nature, and the question arises, How is it
possible1}

§ 1 6. The word nature assumes yet another meaning,
which determines the object, whereas it (nature) in the former
[formal] sense only denotes the conformity to law \_Gesetz-
mdssigkeif\ of the determinations of the existence of things
generally. Nature then considered materially is the complex
of all the objects of experience. And with this only are we
now concerned, for besides, things which can never be
objects of experience, if they must be cognised as to their
nature, would oblige us to have recourse to concepts whose
meaning could never be given in concreto (by any example
of possible experience). Consequently we must form for
ourselves a list of concepts of their nature, the reality
whereof — that is, whether they actually refer to objects, or
are mere creatures of thought — could never be determined.
The cognition of what cannot be an ob-[66] ject of experi
ence would be hyperphysical, and concerning this the sub
ject of our present discussion has nothing to say, but only
concerning the cognition of nature, the reality of which
[cognition] can be confirmed by experience, though it is
possible a priori and precedes all experience.

§ 17. The formal [side] of nature in this narrower sense
is therefore the conformity to law of all the objects of ex
perience, and so far as it is cognised a priori, their necessary
conformity. But it has been just shown that the laws of
nature can never be cognised a priori in objects so far as
they are considered not in reference to possible experience,
but as things in themselves. And our inquiry here extends
not to things in themselves (the properties of which we pass
by), but to things as objects of possible experience, and the
complex of these is what we properly designate as nature.
And now I ask, when the possibility of a cognition of nature

52 PROLEGOMENA TO METAPHYSIC [66-67

a priori is in question, whether it is better to arrange the
problem thus : How could we cognise a priori that things as
objects of experience necessarily conform to law ? or thus :
How is it possible to cognise a priori ti\z necessary conformity
to law of experience itself as regards all its objects gener
ally?

When examined, the solution of the problem, represented
in either way, amounts, with regard to the pure cognition of
nature (which is the point of the question [67] at issue),
entirely to the same thing. For the subjective laws, under
which alone an empirical cognition of things is possible, hold
good of these things, as objects of possible experience (not
as things in themselves, which are not considered here). It
is quite the same whether I say : Without the law, that when
an event is perceived, it is always referred to something that
precedes, which it follows according to a universal rule,
[without this law] a perceptive judgment never can rank as
experience ; or whether I express myself thus : All, of which
experience teaches that it happens, must have a cause.

It is, however, better to choose the first formula. For we
can a priori and previous to all given objects have a cogni
tion of those conditions, on which alone experience with
regard to such objects is possible, but never of the laws to
which they may in themselves be subject, without reference
to possible experience. We cannot therefore study the nature
of things a priori otherwise than by investigating the condi
tions and the universal (though subjective) laws, under which
alone such a cognition as experience (as to mere form) is
possible, and we determine accordingly the possibility of
things, as objects of experience. For if I should choose the
second formula, and seek the conditions a priori, on which
nature as an object of experience is possible, I might easily fall
into error, and fancy that I was speaking of nature as a thing

68-69] HOW IS PURE SCIENCE OF NATURE POSSIBLE ? 53

[68] in itself, and then be endlessly toiling in search
of laws for things of which nothing is given me.

Consequently we shall here be concerned with experience
only, and the universal conditions given a priori of its
possibility, and we shall thence determine nature as the
whole object of all possible experience. I think it will be
understood that I here do not mean the rules of the observa
tion of a nature that is already given, for these already pre
suppose experience ; that I do not therefore mean how we
(by experience) can learn from nature her laws ; for these
would not then be laws a priori, and would yield us no pure
science of nature ; but [I mean to inquire] how the condi
tions a priori of the possibility of experience are at the same
time the sources from which all the universal laws of nature
must be derived.

§ 18. We must then in the first place observe that, though
all judgments of experience are empirical — that is, have
their ground in the immediate perception of the senses —
all empirical judgments are not therefore conversely judg
ments of experience, but that, besides the empirical, and
in general besides what is given to the sensuous intui
tion, particular concepts must yet be superadded — concepts
which have their origin quite a priori in the pure under
standing, and under which every perception must be first
of all subsumed and then by their means changed into ex
perience.

[69]. Empirical judgments, so far as they have objective
validity, are JUDGMENTS OF EXPERIENCE ; but those which
are only subjectively valid, I name mere JUDGMENTS OF
PERCEPTION. The latter require no pure concept of the
understanding, but only the logical connexion of perception
in a thinking subject. But the former always require,
besides the representation of the sensuous intuition,

54 PROLEGOMENA TO METAPHYSIC [69-70

rf particular concepts originally begotten in the understanding,
| which produce the objective validity of the judgment of
I' experience.

All our judgments are at first mere perceptive judgments ;
they hold good merely for us (that is, for our subject), and
we do not till afterwards give them a new reference (to an
object), and desire that they shall always hold good for us
and alike for everybody else ; for when a judgment agrees
with an object, all judgments concerning the same object
must likewise agree among themselves, and thus the
objective validity -of the judgment of experience signifies
nothing else than its ne^ejjSjj^Laiiuveisaii^^
And conversely when we have reason to consider a
judgment necessarily universal (which never depends upon
perception, but upon the pure concept of the understanding,
under which the perception is subsumed), we must consider
it objective also, that is, that it expresses not merely a
reference of our perception to a subject, but a quality of the
object. For there would be no reason for the judg- [70]
ments of other men necessarily agreeing with mine, if it
were not the unity of the object to which they all refer, and
with which they accord ; hence they must all agree with one
another.

§ 19. Objective validity therefore and necessary univer
sality (for everybody) are equivalent notions, and though
we do not know the object in itself, yet when we consider
a judgment as universal, and also necessary, we understand
it to have objective validity. By this judgment we cognise
the object (though it remains unknown as it is in itself) by
the universal and necessary connexion of the perceptions
given to us. As this is the case with all objects of sense,
judgments of experience take their objective validity not
from the immediate cognition of the object (which is

70-7 1] HOW IS PURE SCIENCE OF NATURE POSSIBLE ? 55

impossible), but from the condition of universal validity in
empirical judgments, which, as already said, never rests
upon empirical, or, in short, sensuous conditions, but upon
a pure concept of the understanding. The object always
remains unknown in itself; but when by the concept of the
understanding the connexion of the representations of the
object, which are given to our sensibility, is determined as
universally valid, it (the object) is determined by this
relation, and the judgment is objective.

To illustrate the matter: that the room is warm,1 [71]
sugar sweet, and wormwood bitter — these are merely
subjectively valid judgments. I by no means require, that
I or every other person shall always find them true as I now
do ; they only express a reference of two sensations to the
same subject, to myself, and that only in my present state
of perception ; consequently they are not valid of the object;
such judgments I have named those of perception. Judg
ments of experience are of quite a different nature. What
experience teaches me under certain circumstances, it must
always teach me and everybody, and its validity I do not
limit to the subject or to its state at a particular time.
Hence I pronounce all such like judgments objectively
valid. For instance, when I say the air is elastic, this
judgment is as yet a judgment of perception only — I do

1 I concede at once that these examples do not represent such judg
ments of perception as ever could become judgments of experience,
even though a concept of the understanding were superadded, because
they refer merely to feeling, which everybody knows to be merely
subjective, and which of course can never be attributed to the object,
and consequently never become objective. I only wished at present to
give an example of a judgment that is merely subjectively valid, and
contains in itself no ground for universal validity, and thereby for a
reference to the object. An example of the judgments of perception,
which become judgments of experience by superadded concepts of the
understanding, will be given in the next note.

56 PROLEGOMENA TO METAPHYSIC [71-73

nothing but refer two of my sensations to one another.
But, if I would have it called a judgment of experience,
I require this connexion to stand under a condition,
which makes it universally valid. I desire therefore
[72] that I and everybody else should always conjoin
necessarily the same perceptions under the same circum
stances.

§ 20. We must consequently analyse experience in
general, in order to see what is contained in this product of
the senses and of the understanding, and how the judgment
of experience itself is possible. The foundation is conscious
intuition, that is, perception (pcrceptid), which pertains
merely to the senses. But in the next place, judging also
(which belongs only to the understanding) pertains thereto.
But this judging may be twofold — first, in that I merely
compare perceptions and conjoin them in a consciousness
of my [particular] state, or secondly, in that I conjoin them
in consciousness generally. The former judgment is merely
a judgment of perception, and so far of subjective validity
only : it is merely a connexion of perceptions in my [present]
mental state, without reference to the object. Hence it is
not, as is commonly imagined, enough for experience to
compare perceptions and to connect them in consciousness
through the [comparative] judgment ; there thus arises no
universality and necessity of the judgment, by which alone
it can be objectively valid and [become] experience.

Quite another judgment therefore is required before
perception can become experience. The given intuition
must be subsumed under a concept, which determines the
fnp-n nf judging \n ganami [yj] HativHy t" intuition,
connects its empirical consciousness in consciousness
gcncrallvr^and thereby procures universal validity for
empirical judgments ; a concept of this nature is a pure a

73-74] HOW IS PURE SCIENCE OF NATURE POSSIBLE ? 57

priori concept of the Understanding, which does nothing
but determine for an intuition the general way in which it
can serve for [the process of] judging. Suppose the concept
of cause to be such, then it determines the intuition which
is subsumed under it, e.g. that of air, relative to judging in
general, so that the concept of air serves with regard to [its]
expanding [itself] in the relation of the antecedent to the
consequent in a hypothetical judgment. The concept of
cause then is a pure concept of the understanding, which
is totally distinct from all possible perception, and only
serves to_determine the representation contained jundexutj
relatively to judging in^gejiejral, and so to make a universally
valid judgment possible.

Before, therefore, a judgment of perception can become
a judgment of experience, it is requisite that the perception
should be subsumed under such a concept of the under
standing as we have been describing ; for instance, air ranks
under the concept of causes, which determines our judgment
about it in regard to [its] extending [itself] as hypothetical.1
[74] But this extension [extending] is thereby represented
not as merely belonging to my perception of the air in my
present state or in many of my states or in the state of
perception of others, but as belonging to this perception of
necessity. So this judgment, 'the air is elastic,' becomes
universally valid, and a judgment of experience, only by

1 As an easier example, we may take the following : 'When the sun
shines on the stone, it grows warm.' This judgment, however often I
and others may have perceived it, is a mere judgment of perception,
and contains no necessity ; perceptions are only usually conjoined in
this manner. But if I say, ' The sun warms the stone,' I add to the
perception the understanding-concept \Verstandesbegriff'} of cause,
which necessarily connects with the concept of sunshine that of heat,
and the synthetical judgment becomes of necessity universally valid,
consequently objective, and is converted from a perception into
experience [cf. vol. i. p. 116, note].

58 PROLEGOMENA TO METAPHYSIC [74-75

certain judgments preceding it, which subsume the intuition
of air under the concept of cause and effect : and they
thereby determine the perceptions not merely as regards
one another in me, but relatively to the form of judging in
general (here the hypothetical), and in this way they render
the empirical judgment universally valid.1

If all our synthetical judgments are analysed so far as
they are objectively valid, it will be found that they never
consist of mere intuitions connected only (as is commonly
believed) by comparison [75] in a judgment; but that they
would be impossible were not a pure concept of the under
standing superadded to the concepts abstracted from intui
tion, under which concept these latter are subsumed, and
in this manner only connected in an objectively valid
judgment. Even the judgments of pure Mathematic in
their simplest axioms are not exempt from this condition.
The principle, ' a straight line is the shortest between two
points,' presupposes that the line is subsumed under the
concept of quantity, which certainly is no mere intuition,
but has its seat in the understanding alone, and serves to
determine the intuition (of the line) with regard to the
judgments which may be made about it, relatively to their
quantity, that is, to plurality (as judicia plurativd)? For

1 In the above difficult paragraph, I have translated Ausspannung
and Ausdthmmg in a dynamical and not in a statical sense, according
to Dr. Toleken's suggestion. It is certainly an illustration of obscurum
per obscurius, if taken in any other way. M.

3 I prefer this name for the judgments, which are termed particular
in logic. For the word particular seems to imply the notion that they
are not universal. But when I begin from unity (in singular judgments)
and so proceed to universality, I must not imply any reference to
universality : I think of plurality merely without universality, not as
its exception. This distinction is necessary, if logical distinctions
[Momenti] are to afford the basis of the pure concepts of the under
standing : in logical use the matter is not worth changing.

75-76] HOW IS PURE SCIENCE OF NATURE POSSIBLE ? 59

under them it is understood that in a given intuition there
is contained a plurality of homogenous parts.

§ 21. In order therefore to show the possibility of
experience so far as it rests upon pure concepts of [76] the
understanding a priori, we must first represent what belongs
to judging generally, and the various phases \Momente\ of
the understanding in [performing] it, in a complete table.
For the pure understanding-concepts must run parallel to
these phases, as such concepts are nothing more than
concepts of intuitions in general, so far as these are deter
mined by one or other of these ways of judging, in them
selves, that is, necessarily and universally. Hereby also
the a priori principles of the possibility of all experience,
as of an objectively valid empirical cognition, will be
precisely determined. For they are nothing but propositions
by which all perception is (under certain universal conditions
of intuition) subsumed under those pure concepts of the
understanding.

Logical Table of Judgments.

I. 2.

As to Quantity. As to Quality.

Universal. Affirmative.

Particular [plurative]. Negative.

Singular. Infinite.

3- 4-

As to Relation. As to Modality.

Categorical. Problematical.

Hypothetical. ^ Assertorial.

Disjunctive. Apodeictical.

60 PROLEGOMENA TO METAPHYSIC [77-7*

[77] Transcendental Table of the Pure Concepts of the
Under st a nding.

I. 2.

As to Quantity. As to Quality.

Unity (the Measure). Reality.

Plurality (the Quantity). Negation.

Totality (the Whole). Limitation.

3- 4-

As to Relation. As to Modality.
Substance. Possibility.

Cause. Existence.

Community. Necessity.

Pure Physiological Table of the Universal Principles
of the Science of Nature.

I- 2.

Axioms of Intuition. Anticipations of Perception.

3-
Analogies of Experience.

4-
Postulates of Empirical Thinking generally.

§ 2irt. In order to comprise the whole matter in one
notion, it is first necessary to remind the reader that we are
discussing not the origin of experience, but of that which lies
in experience. The former pertains to empirical psychology,
and would even [78] then never be adequately explained

78-79] HOW IS PURE SCIENCE OF NATURE POSSIBLE ? 61

without the latter, which belongs to the Kritik of cognition,
and particularly of the understanding.

Experience consists of intuitions, which pertain to the
sensibility, and of judgments, which are entirely a work of
the understanding. But the judgments, which the under
standing forms entirely from sensuous intuitions, are far
from being judgments of experience. For in the one case
the judgment connects only the perceptions as they are given
in the sensuous intuition, but in the other the judgments
are to express what experience in general, and not what the
mere perception, with its subjective validity, contains.
The judgment of experience must therefore add to the
sensuous intuition and its logical connexion in a judgment
(after it has been made universal by comparison) something
that determines the synthetical judgment as necessary and
therefore as universally valid. This can be nothing else
than that concept which represents the intuition as deter
mined in itself with regard to one form of judgment rather
than another,1 which [form] is a concept of that synthetical
unity of intuitions which can only be represented by a
given logical function of judgments.

§ 22. The sum of the matter is this : the busi- [79] ness
of the senses is to intuite — that of the understanding is to
think. But thinking means uniting representations in one
consciousness. This union is either merely relative to the
[individual] subject, and is contingent and subjective, or is
absolute, and is necessary or objective. The union of
representations in one consciousness is judgment. Think
ing therefore is the same as judging, or referring represent
ations to judgments in general. Hence judgments are
either merely subjective, when representations are referred

1 I read anderen^ being unable to translate andere of Rosencrantz's
Edition. M.

62 PROLEGOMENA TO METAPHYSIC [79-80

to a consciousness in one subject only, and united in it, or
objective, when they are united in a consciousness generally,
that is, necessarily. The logical phases of all judgments
are but various modes of uniting representations in con
sciousness. But if they serve for concepts, they are concepts
of their necessary union in a consciousness, and so principles
of objectively valid judgments. This union in a conscious
ness is either analytical, by identity, or synthetical, by the
combination and addition of various representations one to
another. Experience consists in the synthetical connexion
of phenomena (perceptions) in consciousness, so far as this
connexion is necessary. Hence the pure concepts of the
understanding are those under which all perceptions must
be subsumed ere they can serve for judgments of experience,
in which the synthetical [80] unity of the perceptions is
represented as necessary and universally valid.1

§ 23. So far as judgments are merely considered the
condition of the union of given representations in a
consciousness, they are rules. These rules, so far as they
represent the union as necessary, are rules a priori^ and so
far as they cannot be deduced from higher rules, are

1 But how does this proposition, 'that judgments of experience
contain necessity in the synthesis of perceptions," agree with my state
ment so often before inculcated, that ' experience as cognition a posteriori
can afiford contingent judgments only ?' When I say that experience
teaches me something, I mean [by experience] only the perception that
lies in it— for example, that heat always follows the shining of the sun
on a stone ; consequently the proposition of experience is always so far
contingent. That this heat necessarily follows the shining of the sun
is contained indeed in the judgment of experience (by means of the
concept of cause), yet is a fact not learned by experience; for
conversely, experience is first of all generated by this addition of the
concept of the understanding (of cause) to perception. How perception
attains this addition may be seen by referring in the Kritik itself to the
section on the Transcendental faculty of Judgment [vol. i. pp. 144 sqq.]

80-82] HOW IS PURE SCIENCE OF NATURE POSSIBLE ? 63

fundamental principles. But in regard to the possibility of
all experience, merely in relation to the form of thinking in
it, no conditions of experience-judgments are higher than
those which bring the phenomena, according to the various
form of their intuition, under pure concepts of the under
standing, and render the empirical judgment [81] objectively
valid. These concepts are therefore the a priori principles
of possible experience.

The principles of possible experience are then at the
same time universal laws of nature, which can be cognised
a priori. And thus the problem in our second question,
How is the pure Science of Nature possible ? is solved. For
the system which is required for the form of a science is to
be met with in perfection here, because, beyond the above-
mentioned formal conditions of all judgments in general
(viz. of all the general rules of logic), no others are possible,
and these constitute a logical system. The concepts
grounded thereupon, which contain the a priori conditions
of all synthetical and necessary judgments, accordingly
constitute a transcendental system. Finally the principles,
by means of which all phenomena are subsumed under
these concepts, constitute a physiological system, that is, a
system of nature, which precedes all empirical cognition of
nature, makes it even possible, and hence may in strictness
be denominated the universal and pure science of nature.

§ 24. The first1 of the physiological principles subsumes
all phenomena, as intuitions in space and [82] time, under
the concept of Quantity, and is so far a principle of the
application of Mathematic to experience. By the second

1 Without referring to what the Kritik itself says on the subject of
the Principles, the three following paragraphs will not be well under
stood ; they may, however, be of service in giving a general view of the
Principles, and in fixing the attention on the main points.

64 PROLEGOMENA TO METAPHYSIC [82-83

that which is empirical, or sensation, which denotes what is
real in intuitions, is not indeed directly subsumed under
the concept of quantity, because sensation is not an
intuition that contains either space or time, though it places
the object related to itself in both. But still there is
between reality (sensible representation) and nothing, or
the total void of intuition in time, a difference which has a
quantity. For between every given degree of light and of
darkness, between every degree of heat and of absolute
cold, between every degree of weight and of absolute
lightness, between every degree of occupied space and of
totally void space, diminishing degrees can be conceived, in
the same manner as between consciousness and total un
consciousness (psychological obscurity) ever diminishing
degrees find their place. Hence there is no perception
that can prove an absolute want ; for instance, no psycho
logical obscurity that cannot be considered as a [weaker]
consciousness, which is only outbalanced by a stronger
consciousness. This occurs in all cases of sensation, and
so the understanding can anticipate even sensations, which
constitute the peculiar quality of empirical representations
(phenomena), by means of this principle : that they all have
(consequently that what is real in all phenomena has) a
degree. Here [83] is the second application of Mathematic
(mathesis intensorum) to the science of nature.

§ 25. As to the Relation of phenomena, and indeed
merely with a view to their existence, the determination is
not mathematical, but dynamical, and can never be ob
jectively valid, consequently never fit for experience, if it
does not come under a priori principles by which the
cognition of experience relative to phenomena becomes even
possible. Hence phenomena must be subsumed under the
concept of Substance, which is the foundation of all deter-

83-84] HOW IS PURE SCIENCE OF NATURE POSSIBLE ? 65

mination of existence, as a concept of the thing itself; or
secondly — so far as a succession is found among pheno
mena, that is, an event — under the concept of an Effect
with reference to Cause ; or lastly — so far as coexistence is
to be known objectively, that is, by a judgment of ex
perience — under the concept of Community (action and
reaction). Thus a priori principles form the basis of
objectively valid, though empirical judgments, that is, of the
possibility of experience so far as it must connect objects
as existing in nature. These principles are the proper laws
of nature, which may be termed dynamical.

And finally the cognition of the agreement and connexion
not only of phenomena among themselves in experience,
but of their relation to experience in general, belongs to the
judgments of experience. This relation [concerns] either
their agreement with the formal conditions, which the
understanding [84] cognises, or their coherence with the
materials of the senses and of perception, or combines both
into one concept. Consequently it contains Possibility,
Actuality, and Necessity according to universal laws of
nature ; and this constitutes the physiological doctrine of
method, or the distinction of truth and of hypotheses, and
the bounds of the certainty of the latter.

§ 26. Yet it is not by any means the greatest merit of
this third table of Principles drawn from the nature of the
understanding itself after the critical method, that it shows
an inherent perfection, which raises it far above every other,
that has hitherto though in vain been tried or may yet be
tried by analysing things themselves dogmatically. Nor is it
[the chief merit] that the table exhibits all synthetical a
Priori principles completely and on one principle, viz. the
faculty of judging in general, which constitutes the essence
of experience as regards the understanding, so that we can

II F

66 PROLEGOMENA TO METAPHYSIC [84-85

be certain that there are no more such like principles — a
satisfaction which the dogmatical method never can afford.

The ground of proof must be carefully noticed, as it
shows the possibility of this cognition a priori, and at the
same time limits all such principles to a condition, which
must never be forgotten, if we desire them not to be mis
understood, and extended in use beyond the original sense
which the under- [85] standing attaches to them. This
limit is, that they contain nothing but the conditions of
possible experience in general so far as it is subjected to
laws a priori. Consequently I do not say, that things in
themselves possess a quantity, [that] their reality [has] a
degree, their existence a connexion of accidents in a
substance, etc. ; for this nobody can prove, because such a
synthetical connexion from mere concepts, without any
reference to sensuous intuition on the one side, or con
nexion of it in a possible experience on the other, is
absolutely impossible. The essential limitation of the
concepts in these principles then is : That all things stand
necessarily a priori under the afore -mentioned conditions,
as objects of experience only.

Hence there follows secondly a specifically peculiar
mode of proof of these principles : That they are not
referred directly to phenomena and their relation, but to
the possibility of experience, of which phenomena constitute
the matter only, not the form. Thus they are referred to
objectively and universally valid synthetical propositions, in
which [features] judgments of experience are distinguished
from those of perception. This takes place because pheno
mena, as mere intuitions, which occupy a part of space and
time, come under the concept of Quantity, which unites
their multiplicity a priori according to rules synthetically.
Again, so far as the perception contains, besides intuition,

86-87] HOW IS PURE SCIENCE OF NATURE POSSIBLE ? 67

sensation, between which [86] and nothing, or its total
disappearance, a transition by diminishing always occurs,
what is real in phenomena must have a Degree, so far
as it does not itself occupy any part of space or of time.1
Still the transition to it from empty time or space is only
possible in time; consequently though sensation, as the
quality of empirical intuition, can never be cognised a priori,
by its specific difference from other sensations, yet it can,
in a possible experience in general, as a quantity of percep
tion be intensively distinguished from every other similar
perception. Hence then the application of Mathematic to
nature is rendered possible and determined, as regards the
sensuous intuition by which nature is given to us.

But the reader must above all pay attention to the mode
of proof of the principles which occur under the title of
Analogies of experience. For [87] these do not regard the
generation of intuitions, like the principles of the application
of mathematic to the science of nature generally, but regard
the connexion of their existence in experience. This
[connexion] can be nothing but the determination of their
existence in time according to necessary laws, under which
alone the connexion is objectively valid, and consequently
becomes experience. The proof therefore does not turn on

1 Heat and light are in a small space just as large (as to degree) as
in a large one ; in like manner the internal representations, pain,
consciousness in general, whether they last a short or a long time, need
not vary as to the degree. Hence the quantity is here in a point and
in a moment just as great as in any space or time however great.
Degrees are therefore capable of increase, but not in intuition, rather in
mere sensation (or the quantity of the degree of an intuition). Hence
they can only be estimated quantitatively by the relation of I to o — that
is, by their capability of decreasing by infinite intermediate degrees to
disappearance, or of increasing from nought through infinite gradations
to a determinate sensation in a certain time. Qtiantitas qualitatis est
gradus.

<>S PROLEGOMENA TO METAPHYSIC [87-88

the synthetical unity in the connexion of things in them
selves, but of perceptions, and of these not in regard to their
matter, but to the determination of time and of the relation
of their existence in it, according to universal laws. These
universal laws, therefore, if the empirical determination in
relative time is to be objectively valid (i.e. to be experience),
contain the necessary determination of existence in time
generally (consequently according to a rule of the under
standing a priori]. The reader has probably been long
accustomed to consider experience a mere empirical syn
thesis of perceptions, and hence not to reflect that it goes
much farther than these extend, as it gives empirical
judgments universal validity, and for that purpose requires
a pure unity of the understanding, which precedes a priori.
In Prolegomena on this subject I can only recommend
such readers to pay great attention to this distinction of
experience from a mere aggregate of perceptions, and to
judge the mode of proof from this point of view.

[88] § 27. This is the proper place to remove Hume's
difficulty. He justly maintains, that we can by no means
see by reason the possibility of Causality, that is, of the refer
ence of the existence of one thing to the existence of another,
which is necessitated by the former. I add, that we com
prehend just as little the concept of Subsistence, that is, the
necessity that at the foundation of the existence of things
there lies a subject which cannot itself be a predicate of any
other thing ; nay, we cannot even form a notion of the
possibility of such a thing (though we can point out examples
of its use in experience). The very same incomprehensibility
affects the Community of things, as we cannot comprehend
how from the state of one thing an inference to the state of
quite another thing beyond it, and vice versa, can be drawn,
and how substances which have each their own separate

88-89] HOW IS PURE SCIENCE OF NATURE POSSIBLE? 69

existence should depend upon one another necessarily.
But I am very far from holding these concepts to be derived
merely from experience, and the necessity represented in
them, to be imaginary and a mere illusion produced in us by
long habit. On the contrary, I have amply shown, that they
and the principles [derived] from them are firmly established
a priori, or before all experience, and have their undoubted
objective value, though only with regard to experience.

§ 28. I have indeed no notion of such a connexion of
things in themselves, that they can either [89] exist as sub
stances, or act as causes, or stand in community with others
(as parts of a real whole), and I can just as little conceive
such properties in phenomena as such, because those con
cepts contain nothing that lies in the phenomena, but what
the understanding alone must think. But we have a con
cept of such a connexion of representations in our under
standing, and in judgments generally — a concept that
representations appear in one sort of judgments as subject
in relation to predicate, in another as reason in relation
to consequence, and in a third as parts, which constitute
together a total possible cognition. Besides we cognise
a priori that without considering the representation of
an object as determined in some of these respects, we can
have no valid cognition of the object, and, if we should
occupy ourselves about the object per se, there is no possible
attribute, by which I could know that it is determined under
any of these aspects, that is, under the concept either of sub
stance, or of cause, or (in relation to other substances) of
community, for I have no notion of the possibility of such a
connexion of existence \_per se\. But the question is not
how things in themselves, but how the empirical cognition
of things is determined, as regards the above aspects of
judgments in general, that is, how things, as objects of ex-

70 PROLEGOMENA TO METAPHYSIC [89-91

perience, can and shall be subsumed under these concepts
of the understanding. And then it is clear, that I com
pletely comprehend not only the [90] possibility, but also
the necessity of subsuming all phenomena under these
concepts, that is, of using them for principles of the possi
bility of experience.

§ 29. Let us make an experiment with Hume's prob
lematical concept (his crux metaphysicorum}^ the concept of
cause. In the first place I am given a prior 7", by means of
logic, the form of a conditional judgment in general, that is,
one given cognition as antecedent and another as consequent.
But it is possible, that in perception we may meet with a
rule of relation, which runs thus : that a certain phenomenon
is constantly followed by another (though not conversely),
and this is a case for me to use the hypothetical judgment,
and, for instance, to say, if the sun shines long enough upon
a body, it grows warm. Here there is indeed as yet no
necessity of connexion, or concept of cause. But I proceed
and say, that if the [above] proposition, which is merely a
subjective connexion of perceptions, is to be a judgment of
experience, it must be considered as necessary and univer
sally valid. Such a proposition would be, ' the sun is by its
light the cause of heat.' The empirical rule is now con
sidered as a law, and as valid not merely of phenomena,
but valid of them for the purposes of a possible experience
which requires thoroughly and therefore necessarily valid
rules. I therefore easily comprehend the concept of cause,
as a concept necessarily belonging to the mere form of ex
perience, [91] and its possibility as a synthetical union of
perceptions in consciousness generally ; but I do not at all
comprehend the possibility of a thing generally as a cause,
because the concept of cause denotes a condition not at all
belonging to things, but to experience. It is nothing in

91-92] HOW IS PURE SCIENCE OF NATURE POSSIBLE ? 71

fact but an objectively valid cognition of phenomena and of
their succession, so far as the antecedent can be conjoined
with the consequent according to the rule of hypothetical
judgments.

§ 30. Hence to the pure concepts of the understanding^
if they quit objects of experience and would refer to things!
in themselves, (noumena) have no signification whatever!
They serve, as it were, only to spell phenomena, that we
may be able to read them as experience; the principles
which arise from their reference to the sensible world, only
serve our understanding for empirical use... Beyond this
they are arbitrary combinations, without objective reality,
and we can neither cognise their possibility a priori, nor
verify their reference to objects or make it intelligible by
any example ; because examples can only be borrowed from
some possible experience, consequently the objects of these
concepts can be found nowhere but in a possible experience.

This complete (though to its originator unexpected)
solution of Hume's problem preserves therefore to the pure
concepts of the understanding their [92] a priori origin, and
to the universal laws of nature their validity, as laws of the
understanding, yet so that their use is limited to experience,
because their possibility depends solely on the reference of
the understanding to experience ; but not by deriving them
from experience, but by deriving it from them, a completely
reversed mode of connexion which never occurred to Hume.

This is therefore the result of all our foregoing inquiries :
all synthetical principles a priori are nothing more than
principles of possible experience, and can never be referred
to things in themselves, but to phenomena as objects of ex
perience. And hence pure mathematic as well as pure
physic can never be referred to anything more than mere
phenomena, and can only represent either that which makes

72 PROLEGOMENA TO METAPHYSIC [92-93

experience generally possible, or else that which, as it is
derived from these principles, must always be capable of
being represented in some possible experience.

§ 31. And thus we have at last something definite, upon
which to depend in all metaphysical undertakings, which
have hitherto attempted everything without distinction
boldly enough but always at random. It never struck
dogmatical thinkers, that the aim of their exertions should
be so proximate. It never struck even those, who, con
fident in their supposed sound common sense, started with
concepts and principles of pure reason (which were [93]
legitimate and natural, but destined for mere empirical use)
in quest of fields of knowledge \Einsichten\, to which they
neither knew nor could know any determinate bounds,
because they had never reflected nor were able to reflect on
the nature or even on the possibility of such a pure under
standing.

Many a naturalist of pure reason (by which I mean the
man who believes he can decide in matters of Metaphysic
without any science) may pretend, that he long ago by the
prophetic spirit of his sound sense, not only suspected, but
knew and comprehended, what is here propounded with so
much ado, or, if he likes, with prolix and pedantic pomp :
' that with all our reason we can never reach beyond the
field of experience.' But when he is questioned about his
rational principles individually, he must grant, that there are
many of them which he has not taken from experience, and
which are therefore independent of it and valid a priori.
How then and on what grounds will he restrain both him
self and the dogmatist, who makes use of these concepts
and principles beyond all possible experience, because they
are recognised independent of it ? And even he, this adept
in sound sense, in spite of all the cheaply acquired wisdom

93-951 HOW IS PURE SCIENCE OF NATURE POSSIBLE ? 73

he arrogates to himself, is not so secure from [the danger
of] wandering insensibly beyond objects of experience into
the field of chimeras. He too is often deeply enough [94]
involved in them, though he gives a colour to his groundless
pretensions by his popular language, in which he announces
everything as mere probability, rational conjecture, or
analogy.

§ 32. Since the oldest days of philosophy inquirers into
pure reason have conceived, besides the things of sense,
or appearances (phenomena), which make up the sensible
world, certain objects of the understanding1 (noumend),
which should constitute an intelligible world. And as
appearance and illusion were by those men identified (a
thing which we may well excuse in an undeveloped epoch),
actuality was only conceded to the noumena.

And we indeed, when, as is reasonable, we consider
objects of sense as mere appearances, hereby confess that
they are based upon a thing in itself, though we know not
this thing as to its internal constitution, but only know its
phenomena, viz. : the way in which our senses are affected
by this unknown something. The understanding therefore,
by assuming phenomena, grants the existence of things in
themselves also, and so far we may say, that the repre
sentation of such beings as form the basis of phenomena,
consequently of mere beings of the understanding, is not
only admissible, but unavoidable.

Our critical deduction by no means excludes [95] beings
of that sort (noumena) , but rather limits the principles of the
Aesthetic to this, that they shall not extend to all things, as
everything would then be turned into mere phenomenon,
but that they shall only hold good of objects of possible
experience. Hereby then objects of the understanding are
1 Verstandeswesen , using object in its vaguest sense. M.

74 PROLEGOMENA TO METAPHYSIC [95-96

granted, but with the inculcation of this rule which admits
of no exception : ' that we neither know nor can know any
thing at all determinate of these pure objects of the under
standing, because our pure concepts of the understanding as
well as our pure intuitions extend to nothing but objects of
possible experience, consequently to mere things of sense,
and as soon as we leave this sphere these concepts retain no
meaning whatever.'

§ 33. There is indeed something seductive in our pure
concepts of the understanding, which tempts us to a tran
scendent use ; I mean the use which transcends all possible
experience. Not only are our concepts of substance, of
power, of action, of reality, and others, quite independent
of experience, containing no phenomenon of sense, and so
apparently applicable to things in themselves (noumena),
but, what strengthens this presumption, they contain a
necessity of determination in themselves, which experience
never attains. The concept of cause implies a rule, accord
ing to which one state follows another necessarily; but
experience can only show us, that one state of things often,
or at most, [96] commonly, follows another, and therefore
affords neither strict universality, nor necessity.

Hence the Categories seem to have a deeper meaning
and import than can be exhausted by their empirical use,
and so the understanding insensibly adds for itself to the
house of experience a much more extensive wing, which it
fills, with nothing but creatures of thought, without ever
observing that it has transgressed with its otherwise lawful
concepts the bounds of their use.

§ 34. I was obliged therefore to institute two important,
and even indispensable, though very dry investigations. In
the one (Krttik, p. 107) it is shown, that the senses furnish
not the pure concepts of the understanding in concrete, but

96-97] HOW IS PURE SCIENCE OF NATURE POSSIBLE ? 75

only the schema for their use, and that the object conform
able to it occurs only in experience (as the production of
the understanding from materials of the sensibility). In the
other (Kritik) p. 178) it is shown, that, although our pure
concepts of the understanding and our principles are inde
pendent of experience, and despite of the apparently greater
sphere of their use, still nothing whatever can be thought
by them beyond the field of experience, because they can
do nothing but merely determine the logical form of the
judgment relatively to given intuitions. But as there is no
intuition at all beyond the field of the sensibility, these pure
concepts, as they cannot possibly be exhibited in concrete,
are [then] totally [97] without meaning; consequently all
these nonmena, together with their complex, the intelligible
world,1 are nothing but representation of a problem, of which
the object in itself is possible, but the solution, from the
nature of our understanding, totally impossible. For our
understanding is not a faculty of intuition, but of the con
nexion of given intuitions in experience. Experience must
therefore contain all the objects for our concepts ; but
beyond it no concepts have any signification, as there is no
intuition for their basis.

§ 35. The imagination may perhaps be forgiven for
occasional extravagance, and for not keeping carefully within
the limits of experience, since it at least gains life and vigour

1 Not (as the usual expression is) intellectual world. For cognitions
are intellectual through the understanding, and refer to our world of
sense also ; but objects, so far as they can be represented merely by the
understanding^ and to which none of our sensible intuitions can refer,
are termed intelligible. But as some possible intuition must correspond
to every object, we must conceive an understanding that intuites things
immediately ; but of such we have not the least notion, nor have we of
the things of understanding [Verstandeswesen], to which it should be
applied.

76 PROLEGOMENA TO METAPHYSIC [97-98

by such flights, and since it is always easier to moderate its
boldness, than to stimulate its languor. But the under
standing which ought to think can never be forgiven for
substituting extravagance ; for we depend upon it alone for
assistance to set bounds, when necessary, to the extrava
gance of the imagination.

[98] But the understanding begins its vagaries very
innocently and modestly. It first separates the elementary
cognitions, which inhere in it prior to all experience, but
yet must always have their application in experience. It
gradually drops these limits, and what is there to prevent it,
as it has quite freely derived its principles from itself? And
then it proceeds first to newly-imagined powers in nature,
then to beings outside nature ; in short to a world, for whose
construction the materials cannot be wanting, because fertile
fiction furnishes them abundantly, and though not confirmed,
is never refuted, by experience. This is the reason that
young thinkers are so partial to Metaphysic of the truly
dogmatical kind, and often sacrifice to it their time and
their talents, which might be otherwise better employed.

But there is no use in trying to moderate these fruitless
endeavours of pure reason by all manner of cautions as to
the difficulties of solving questions so occult, by complaints
of the limits of our reason, and by degrading our assertions
into mere conjectures. For, if their impossibility is not dis
tinctly shown, and the self-knowledge of reason does not
become a true science, in which the field of its right use is
distinguished, so to say, with mathematical certainty from
that of its worthless and idle use, these fruitless efforts will
never be fully abandoned.

99-ioo] HOW IS PURE SCIENCE OF NATURE POSSIBLE? 77

[99] §36- How is Nature itself possible 1

This question — the highest point that transcendental
philosophy can ever reach, and to which, as its boundary
and completion, it must proceed — properly contains two
[subordinate] questions.

FIRST: How is nature at all possible in the material
sense, as to intuition, [I mean nature] considered as the
complex of phenomena ; how are space, time, and that which
fills both — the object of sensation, in general possible ?
The answer is : By means of the constitution of our
Sensibility, according to which it is specifically affected by
objecjs, which are in themselves unknown to it, and totally
distijicLJbwn those phenomena. This answer is given in
the Kritik itself in the transcendental Aesthetic, and in these
Prolegomena by the solution of the first general problem.

SECONDLY : How is nature possible in the formal sense,
nature as the complex of the rules, under which all pheno
mena must come, in order to be thought as connected in
experience ? The answer must be this : It is only possible
by means of the constitution of our Understanding, according
to which all the above representations of the sensibility are
necessarily referred to a consciousness, and by which the
peculiar way in which we think (that is, by rules), and hence
experience also, are possible, but must be clearly distin
guished from an insight [100] into the objects in themselves.
This answer is given in the Kritik itself in the transcend
ental Logic, and in these Prolegomena, in the course of the
solution of the second main problem.

But how this peculiar property of our sensibility itself is
possible, or that of our understanding and of the appercep
tion which is necessarily its basis and that of all thinking —
this cannot be further resolved or answered, because we

78 PROLEGOMENA TO METAPHYSIC [100-101

require these [faculties] for all our answers and for all our
thinking about objects.

There are many laws of nature, which we can only know
by means of experience ; but conformity to law in the con
nexion of phenomena, that is, nature in general, we cannot
discover by any experience, because experience itself requires
laws, which are a priori at the basis of its possibility.

The possibility of experience in general is therefore at
the same time the universal law of nature, and the principles
of the former (experience) are the very laws of the latter
(nature). For we do not know nature but as the complex
of the phenomena, that is, of representations in us, and
hence can only jerive the laws of its connexion from the
r2rjnciples of thejr_connexion in us, that is, from the condi
tions of their necessary union in consciousness, which union
constitutes the possibility of experience.

Even the main proposition expounded throughout this
section — that universal laws of nature can [101] be distinctly
cognised a priori — leads naturally to the proposition : that
the highest legislation of nature must lie in ourselves (that is,
in our understanding), and that we must not seek the universal
laws of nature in nature by means of experience, but con
versely must seek nature, as to its universal conformity to law,
in the conditions of the possibility of experience, which lie in
our sensibility and in our understanding. For how were it
otherwise possible to know a priori these laws, as they are
not rules of analytical cognition, but really synthetical exten
sions of it ? Such a necessary agreement of the principles
of possible experience with the laws of the possibility of
nature, can only proceed from one of two reasons : either
these laws are drawn from nature by means of experience,
j or conversely nature is derived from the laws of the possi
bility of experience in general, and is quite the same as the

ioi-io2] HOW IS PURE SCIENCE OF NATURE POSSIBLE? 79

mere universal conformity to law of the latter. The former
is self-contradictory, for the universal laws of nature can and
must be cognised a priori (that is, independent of all experi
ence), and be the foundation of all empirical use of the under
standing; the latter alternative therefore alone remains.1

[102] But we must distinguish the empirical laws of
nature, which always presuppose particular perceptions, from
J±L£_pure or universal laws of nature, which, without being
based on particular perceptions, contain merely the condi
tions of their necessary union in experience. Iri_relation_to
the latter, natiji^j.nd^££^expe£ience are quite the_same.
and as the conformity to law here depends upon the
necessary connexion of phenomena in experience (without
which we cannot cognise any object whatever in the sensible
world), consequently upon the original laws of the under
standing, it seems at first strange, but is not the less certain,
to says as regards the latter : The understanding does
not draw its laws (a priori] from nature, but prescribes them
to it

§ 37. We shall illustrate this apparently daring proposi
tion by an example, which will show, that laws, which we
discover in objects of sensuous intuition (especially when
these laws are cognised as necessary), are commonly held
by us to be such as the understanding has placed in them,
though they are similar in all points to the laws of nature,
which we ascribe to experience.

1 Crusius alone thought of a compromise : that a Spirit, who can
neither err nor deceive, implanted these laws in us originally. But
since false principles often intrude themselves, as indeed the very
system of this man shows in not a few examples, we are involved in
difficulties as to the use of such a principle in the absence of sure
criteria to distinguish the genuine origin from the spurious, as we never
can know certainly what the Spirit of truth or the father of lies may have
instilled into us.

8o PROLEGOMENA TO METAPHYSIC [102-104

§ 38. If we consider the properties of the circle, by [103]
which this figure unites so many arbitrary determinations
of space in itself, and therefore in a universal rule, we can
not avoid attributing a nature to this geometrical thing.
Two right lines, for example, which intersect one another
and the circle, however they may be drawn, are always
divided so that the rectangle under the segments of the one
is equal to that under the segments of the other. The
question now is : Does this law lie in the circle or in the
understanding, that is, Does this figure, independently of
the understanding, contain in itself the ground of the law,
or does the understanding, having constructed according to
its concepts (according to the equality of the radii) the figure
itself, introduce into it this law of the chords cutting one
another in geometrical proportion ? When we follow the
proofs of this law, we soon perceive, that it can only be de
rived from the condition on which the understanding founds
the construction of this figure, and which is that of the
equality of the radii. But, if we enlarge this concept, to
pursue further the unity of various properties of geometrical
figures under common laws, and consider the circle as a
conic section, which of course is subject to the same funda
mental conditions of construction as other conic sections,
we shall find, that all the chords, which intersect within the
ellipse, parabola, and hyperbola, always intersect so that the
rectangles under their segments are not indeed equal, [104]
but always bear a constant ratio to one another [the
directions of the chords being fixed]. If we proceed still
farther, to the fundamental laws of physical astronomy, we
find a physical law of reciprocal attraction diffused over all
material nature, the rule of which attraction is : ' that it
decreases inversely as the square of the distance from each
attracting point, that is, as the spherical surfaces, over which

104-105] HOW IS PURE SCIENCE OF NATURE POSSIBLE? 81

this power diffuses itself — increase,' which law seems to be
necessarily inherent in the very nature of things, and hence
is usually propounded as cognisable a priori. Simple as
the sources of this law are, merely resting upon the relation
of spherical surfaces of different radii, its consequences are
so valuable with regard to the variety of their agreement and
its regularity, that not only are all possible orbits of the
celestial bodies conic sections, but such a relation of these
orbits to each other results, that no other law of attraction,
than that of the inverse square of the distance, can be
imagined as fit for a cosmical system.

Here then is a Nature that rests upon laws which the
understanding cognises a priori, and chiefly from the
universal principles of the determination of space. And the
question now is : Do the laws of nature lie in space, and
does the understanding learn them by merely endeavouring
to find out the fruitful meaning that lies in space ; or do
they [105] inhere in the understanding and in the way in
which it determines space according to the conditions of the
synthetical unity in which its concepts are all centred?
Space is something so uniform and as to all particular
properties so indeterminate, that we should certainly not
seek a store of laws of nature in it. Whereas that which
determines space to the form of a circle or to the figures of,
a cone and a sphere, is the understanding, so far as it
contains the ground of the unity of their constructions.
The mere universal form of intuition, called space, must
therefore be the substratum of all intuitions determinable to
particular objects, and in it of course the condition of the
possibility and of the variety of these intuitions lies. But
the unity of the objects is entirely determined by the under
standing, and on conditions which lie in its own nature ; and
thus the understanding js the origin nf the universal order
II G

82 PROLEGOMENA TO METAPHYSIC [105-106

pi-iiatiire+JUi that it compreb.ends_a]JLjj)pearances underjts
wSj nrd thereby first constructs, a priori* experience

(as to its form), by means of which whatever is to be cog
nised only by experience, is subjected to its laws necessarily.
For we are not now concerned with the nature of things in
themselves, which is independent of the conditions both of
our sensibility and our understanding, but with nature, as
an.j)bj(ect^L-pos8ible experience, and [106] in~tRTs~caselhe
understanding, whilst it makes experience possible, thereby
insists that the sensuous world is either not an object of
experience at all, or must be Nature.

APPENDIX TO THE PURE SCIENCE OF NATURE

§ 39. Of the System of the Categories

THERE can be nothing more desirable to a philosopher,
than to be able to derive the scattered multiplicity of the
concepts or the principles, which had occurred to him in
concrete use, from a principle a priori, and to unite every
thing in this way in one cognition. He formerly only
believed that those things, which remained after a certain
abstraction, and seemed by comparison among one another
to constitute a particular kind of cognitions, were completely
collected ; but this was only an Aggregate. Now he
knows, that just so many, neither more nor less, can consti
tute the mode of cognition, and perceives the necessity of
his division, which is a [mental] comprehension ; and now
only he has attained a System.

To search in common cognition for the concepts, which
do not rest upon particular experience, and yet occur in all
cognition of experience, [107] in which they as it were consti
tute the mere form of connexion — to do this presupposes
neither greater reflection nor deeper insight, than to detect in
a language the rules of the actual use of words generally, and
thus to collect elements for a grammar. In fact both
researches are very nearly related, even though we are not
able to give a reason why each language has just this and

84 PROLEGOMENA TO METAPHYSIC [107-108

no other formal constitution, and still less why an exact
number of such formal determinations in general are found
in it.

Aristotle collected ten pure elementary concepts under
the name of Categories.1 To these, which are also called pre
dicaments, he found himself obliged afterwards to add five
post-predicaments,2 some of which however (prius, simul^
and motus} are contained in the former ; but this random
collection must rather be considered (and commended) as
a hint for future inquirers, than as a regularly developed
idea, and hence it has, in the present more advanced
state of philosophy, been rejected as quite useless.

After long reflection on the pure elements of human
knowledge (those which contain nothing empirical), I at
last succeeded in distinguishing [108] with certainty and in
separating the pure elementary notions of the Sensibility (space
and time) from those of the Understanding. Thus the yth,
8th, and Qth Categories are excluded from the old list.
And the others were of no service to me ; because there
was [in Aristotle's mind] no principle, on which the under
standing could be fully investigated, and all the functions,
whence its pure concepts arise, determined completely and
with precision.

But in order to discover such a principle, I looked about
for an act of theoindezstanding which rnrnprjsf s all fh** rp^
and is distinguished only by various modifications or
phases, in reducing the multiplicity of representation to
the unity of thinking in general : I found this act of the
understanding to consist in judging. Here then the labours
of the logicians were ready at hand, though not yet quite

1 i. Substantia. 2. Qualitas. 3. Quantitas. 4. Relatio. 5. Adio.
6. Passt'o. 7. Quando. 8. Ubi. 9. Situs. 10. Habitus.

2 Oppositum. Prius. Simiil. Motus. Habere.

108-109] OF THE SYSTEM OF THE CATEGORIES 85

free from defects, and with this help I was enabled to
exhibit a complete table of the pure functions of the under
standing, which are however undetermined in regard to any
object. I finally referred these functions of judging to
objects in general, or rather to the condition oLd
iudgments_as_pbjectively valid, and so there arose
concepts of t.h& understanding, concerning which I could
make certain, that these, and this exact number only, con
stitute our whole cognition of things from pure under
standing. I was justi- [109] fied in calling them by their
old name, Categories ; while I reserved for myself the
liberty of adding, under the title of Predicables^ a complete
list of all the concepts deducible from them, by combinations
whether among themselves, or with the pure form of the
phenomenon (space or time), or with its matter, so far as it
is not yet empirically determined (the object of sensation
in general). This should be done as soon as a system of
transcendental philosophy, towards which I am at present
only contributing by the Kritik of the Reason itself, comes
to be constructed.

Now the essential point in this system of Categories,
which distinguishes it from the old random collection
without principle, and for which alone it deserves to be
considered as philosophy, consists in this : that by means
of it the true signification of the pure concepts of the
understanding and the condition of their use could be pre
cisely determined. For here it became obvious that they
are themselves nothing but logical functions, and as such
do not produce the least concept of an object, but require
sensuous intuition as a basis. They therefore only serve to
determine empirical judgments, which are otherwise un
determined and indifferent as regards all functions of
judging, relatively to these functions, thereby procuring

86 PROLEGOMENA TO METAPHYSIC [109-111

them universal validity, and by means of them making
judgments of experience in general possible.

[no] Such an insight into the nature of the categories,
which limits them at the same time to the mere use of
experience, never occurred either to their first author, or to
any of his successors; but without this insight (which
immediately depends upon their derivation or deduction),
they are quite useless and only a miserable list of names,
without explanation or rule for their use. Had the ancients
ever conceived such a notion, doubtless the whole study of
the pure rational knowledge, which under the name of
Metaphysic has for centuries spoiled many a sound mind,
would have reached us in quite another shape, and would
have enlightened the human understanding, instead of
actually exhausting it in obscure and vain subtilties, and
rendering it unfit for true science.

Again : this system of categories makes all treatment
of every object of pure reason itself systematic, and affords
a direction or clue how and through what points of
inquiry every metaphysical consideration must proceed, in
order to be complete ; for it exhausts all the momenta of
the understanding, among which every concept must be
classed. In like manner the table of Principles found its
origin, the completeness of which we can only vouch for by
the system of the categories ; and even in the division of
the concepts,1 which must go [i 1 1] beyond the physiological
use of the understanding, it is the very same clue, which, as
it must always be carried through the same fixed points
determined a priori in the human understanding, always
forms a closed circle ; so that there is no doubt that the
object of a pure understanding or of a rational-concept, so
far as it is to be estimated philosophically and on a priori
1 Kritik, pp. 207 and 257.

1 1I-U2] OF THE SYSTEM OF THE CATEGORIES 87

principles, can in this way be completely cognised. I could
not therefore omit to make use of this clue with regard to
one of the most abstract ontological divisions, the various
distinctions of the notions of something and of nothing, and
to construct accordingly (Kritik, p. 207) a regular and
necessary table of their divisions.1

[112] And this system, like every other true one founded
on a universal principle, shows its inestimable value in this,
that it excludes all foreign concepts, which might otherwise
intrude among the pure concepts of the understanding, and
determines the place of every cognition. Those concepts,
which under the name of concepts of reflection have been
likewise arranged in a table, according to the clue of the
categories, intrude themselves, without leave or right, among
the pure concepts of the understanding in Ontology, though
these are concepts of connexion, and thereby of the objects
themselves, whereas the former are only concepts of the

1 Many neat observations may be made on the table of the categories,
for instance : (i) that the third arises from the first and the second
joined in one concept ; (2) that in those of Quantity and of Quality
there is merely a progress from unity to totality or from something to
nothing (for this purpose the categories of Quality must stand thus :
reality, limitation, total negation), without correlata or opposita^ whereas
those of Relation and of Modality carry such with them ; (3) that, as in
Logic categorical judgments are the basis of all others, so the category of
Substance is the basis of all concepts of actual things ; (4) that as
Modality in the judgment is not a particular predicate, so by the modal
concepts a determination is not superadded to things, etc. etc. Such
observations are of great use. If we besides enumerate all the predic-
ables, which we can find pretty completely in any good ontology (for
example, Baumgarten's), and arrange them in classes under the categories,
in which operation we must not neglect to add as complete a dissection
of all these concepts as possible, there will then arise a merely
analytical part of Metaphysic, which does not contain a single synthetical
proposition, which might precede the second (the synthetical), and would
by its precision and completeness be not only useful, but, in virtue of
its system, be even to some extent elegant.

SS PROLEGOMENA TO METAPHYSIC [112-113

mere comparison of concepts already given, and are hence
of quite another nature and use ; by my orderly division x
they are saved from this confusion. But the value of my
separate table of the categories will be still more obvious,
when we presently separate the table of the transcendental
concepts of Reason, which are of quite another nature and
[113] origin, and hence must have quite another form from
the concepts of the understanding. This so necessary
separation has never yet been made in any system of
Metaphysic [where on the contrary] these rational Ideas
live with the categories without separation, like the children
of one family — a confusion not to be avoided in the absence
of a definite system of categories.

1 Kritik, p. 190 sqq.

[n4] THIRD PART OF THE MAIN TRAN
SCENDENTAL PROBLEM

How is Metaphysic in General Possible ?

§40. PURE Mathematic and pure Science of Nature had
no occasion for such a deduction, as we have made of both,
for their own safety and certainty; for the former rests upon
its own evidence ; and the latter (though sprung from pure
sources of the understanding) upon experience and its
thorough confirmation, which latter testimony Physic can
not altogether refuse and dispense with ; because with all
its certainty, it can never, as philosophy, rival Mathematic.
Both sciences therefore stood in need of this inquiry, not
for themselves, but for the sake of another science, Meta
physic.

Metaphysic has to do not only with concepts of nature,
which always find their application in experience, but with
pure rational Concepts, which never can be given in any
possible experience, consequently with concepts whose
objective reality (as different from mere chimeras), and
with assertions whose truth or falsity, cannot be discovered
or confirmed by any experience. This part of Metaphysic
[115] is precisely what constitutes its essential end, to
which the rest is only a means, and thus this science
requires a similar deduction for its own sake. The third

90 PROLEGOMENA TO METAPHYSIC [115-116

question now proposed relates therefore as it were to the
root and essential difference of Metaphysic, that is, the
occupation of Reason with itself, and the supposed
knowledge of objects arising immediately from this incuba
tion of its own concepts, without requiring, or indeed being
able to reach that knowledge through, experience.1

Without resolving this question reason never does itself
justice. The empirical use to which reason limits the pure
understanding, does not satisfy its proper destination.
Every single experience is only a part of the whole sphere
of its domain, but the absolute totality of all possible ex
perience is itself not experience. Yet it is a necessary
problem for Reason, the mere representation of which
requires concepts quite different from the Categories, whose
use is only immanent, or refers to experience, so [116] far
as it can be given. Whereas the concepts of Reason
extend to the completeness, that is, the collective unity of
all possible experience, and thereby exceed every given
experience, and become transcendent.

As the understanding stands in need of categories for
experience, Reason contains in itself the source of Ideas,
by which I mean necessary notions, whose object cannot
be given in any experience. The latter are inherent in the
nature of Reason, as the former are in that of the under
standing ; and if the categories carry with them an illusion
likely to mislead, in the Ideas it is inevitable, though it
certainly can be kept from misleading us.

As all illusion consists in holding the subjective ground

1 If we can say, that a science is acttcal, at least in the idea of all
men, as soon as it appears that the problems which lead to it are
proposed to everybody by the nature of human reason, and that hence
many (though faulty) essays in it are always unavoidable, then we are
bound to say, that Metaphysic is subjectively (and indeed necessarily)
actual, and therefore we justly ask, how is it (objectively) possible.

116-117] OF THE SYSTEM OF THE CATEGORIES 91

of our judgments to be objective, a self-knowledge of pure
reason in its transcendent (exaggerated) use is the sole
preservative from the aberrations into which reason falls
when it mistakes its destination, and refers that to the
object transcendently, which only regards its own subject
and its guidance in all immanent use.

§ 41. The distinction of Ideas, that is, of pure concepts
of Reason, from Categories, or pure concepts of the
understanding, as cognitions of a quite distinct species,
origin and use, is so important a point in founding a
science which is- to contain the system of all these a priori
cognitions, that without this distinction metaphysic is ab
solutely [117] impossible, or is at best a random, bungling
attempt to build a castle in the air without a knowledge of
the materials or of their fitness for any purpose. Had the
Kritik of Pure Reason done nothing but first point out this
distinction, it had thereby contributed more to clear up our
notions and to guide our inquiry in the field of metaphysic,
than all the vain efforts which have hitherto been made to
satisfy the transcendent problems of pure reason, without
ever surmising that we were in quite another field than that
of the .understanding, and hence classing concepts of the
understanding and those of Reason together, as if they were
of the same kind.

§ 42. All pure cognitions of the understanding have this
feature, that their concepts present themselves in experience,
and their principles can be confirmed by it ; whereas the
transcendent cognitions of Reason cannot, either as Ideas^
appear in experience, or as propositions ever be confirmed
or refuted by it. Hence whatever errors may slip in
unawares, can only be discovered by pure Reason itself —
a discovery of much difficulty, because this very Reason
naturally becomes dialectical by means of its Ideas, and

92 PROLEGOMENA TO METAPHYSIC [117-119

this unavoidable illusion cannot beJimjted bv any objective
and dogmatical researches into things, but^py a subjective
investigationof reason itself as a source of Ideas. _.

§ 43. In the Kritik of Pure Reason it was always my
greatest care to endeavour not only carefully to [118] dis
tinguish the [various] species of cognition, but to derive
notions belonging to each one of them from their common
source. I did this in order that by knowing whence they
originated, I might determine their use with safety, and also
have the very novel but incalculable advantage of knowing
the completeness of my enumeration, classing, and speci
fication of concepts a priori, and therefore according to
principles. Without this [security] metaphysic is mere
rhapsody, in which no one knows whether he has enough,
or whether and where something is still wanting. We can
indeed have this advantage only in pure philosophy, but of
this philosophy it constitutes the very essence.

As I had found the origin of the categories in the four
logical functions of all the judgments of the understanding,
it was quite natural to seek the origin of the Ideas in the
three functions of the syllogisms of Reason ; for as soon as
these pure concepts of Reason (the transcendental Ideas)
are given, they could hardly, except they be held innate, be
found anywhere else, than in the same act of Reason.
This, so far as it regards mere form, constitutes the logical
element of the syllogisms of Reason ; but, so far as it repre
sents the judgments of the understanding as determined
relatively to the one or to the other form a priori, con
stitutes transcendental concepts of pure Reason.

The formal distinction of syllogisms renders [119] their
division into categorical, hypothetical, and disjunctive
necessary. The concepts of Reason founded on them
contained therefore, first, the Idea of the complete subject

H9-I20] OF THE SYSTEM OF THE CATEGORIES 93

(the substantial) ; secondly, the Idea of the complete series
of conditions ; thirdly, the determination of all concepts in
the Idea of a complete complex of [all] possible [being].1
The first Idea is psychological, the second cosmological,
the third theological, and, as all three give occasion to
Dialectic, yet each in its own way, the division of the
whole Dialectic of pure reason into its Paralogism, its Anti
nomy, and its Ideal, was arranged accordingly. Through this
deduction we may feel assured that all the claims of pure
reason are completely represented, and that none can be
wanting ; because the faculty of Reason itself, whence they
all take their origin, is thereby completely surveyed.

§ 44. In these general considerations it is also [120]
remarkable that the Idea of Reason is not, like the cate
gories, of any service to the use of our understanding in
experience, but with respect to that use is quite dispensable,
and even an impediment to the maxims of the rational
cognition of nature, though necessary in another aspect still
to be determined. Whether the soul is or is not a simple
substance, is of no consequence to us in the explanation of
its phenomena. For we cannot render the notion of a
simple being intelligible by any possible experience sensu
ously or in concrete. The notion is therefore quite void as
regards all hoped-for insight into the cause of phenomena,

1 In disjunctive judgments we consider all possibility as divided in
relation to a particular concept. The ontological principle of the
thorough determination of a thing in general (viz., one of all possible
opposite predicates belongs to everything), which is at the same time the
principle of all disjunctive judgments, presupposes the complex of all
possibility, in which the possibility of everything in general is con
sidered as determined [reading bestimmf\. This may serve as a slight
explanation of the above proposition : that the act of Reason in dis
junctive syllogisms is formally the same as that by which it accomplishes
the Idea of a complex of all reality, which contains in itself the positive
[member] of all [pairs of] contradictory predicates.

94 PROLEGOMENA TO METAPHYSIC [120-121

and cannot at all serve as a principle of the explanation of
that which internal or external experience supplies. So the
cosmological Ideas of the beginning of the world or of its
eternity (a parte ante) cannot be of any greater service to us
for the explanation of any event in the world itself. And
finally we must, according to a right maxim of the philosophy
of nature, refrain from all explanations of the design of
nature, drawn from the will of a Supreme Being ; because
this [mode of explanation] is not natural philosophy, but an
acknowledgment that we have come to the end of it. The use
of these Ideas, therefore, is quite distinct from that of those
categories by which (and by the principles built upon which)
experience itself first becomes possible. But our laborious
Analytic of the understanding would be [121] superfluous if
we had nothing else in view than the mere cognition of
nature as it can be given in experience ; for reason does its
work, both in mathematic and in the science of nature,
quite safely and well without any of this subtile deduction ;
our Kritik of the Understanding therefore combines with
the Ideas of pure Reason for a purpose placed beyond the
empirical use of the understanding, which we have already
declared to be in this aspect totally impossible, and without
any object or meaning. But yet there must be harmony
between that which belongs to the nature of Reason and to
that of the understanding, and the former must contribute
to the perfection of the latter, and cannot possibly confuse it.
The solution of this question is as follows : Pure reason
does not in its Ideas point to particular objects, which lie
beyond the field of experience, but only requires complete
ness of the use of the understanding in the system of
experience. But this completeness can be a completeness
of principles only, not of intuitions and of objects. In
order however to represent the Ideas to itself determinately,

I2I-I23] OF THE SYSTEM OF THE CATEGORIES 95

Reason conceives them as the cognition of an object which
[cognition] is as regards these rules completely determined
(though the object is only an Idea), for the purpose of
bringing the cognition of the understanding as near as
possible to the completeness which that Idea denotes.

[122] Prefatory Remark to the Dialectic of Pure Reason.

§ 45. We have above shown (in §§33 and 34) that the
purity of the categories from all admixture of sensuous
determinations may mislead reason into extending their use,
quite beyond all experience, to things per se ; though as
these categories themselves find no intuition which can give
them meaning or sense in concrete, they (as mere logical
functions) can represent a thing in general, but not give by
themselves alone a determinate concept of anything. Such
hyperbolical objects are distinguished by the appellation of
Noiimena, or pure beings of the understanding (or better,
beings of thought), such as, for example, substance, but con
ceived without permanence in time, or cause, but not acting
in time, etc. Here predicates, that only serve to make the
conformity-to-law of experience possible, are applied to these
concepts, and yet they are deprived of all the conditions of
intuition, on which alone experience is possible, and so these
concepts lose all signification.

There is no danger of the understanding spontaneously
making an excursion so very wantonly beyond its own
bounds into the field of the mere creatures of thought, with
out being impelled by foreign laws. But when Reason,
which cannot be fully satisfied with any empirical use of the
rules [123] of the understanding, as being always con
ditioned, requires a completion of this chain of conditions,
then the understanding is forced out of its sphere. And

96 PROLEGOMENA TO METAPHYSIC [123-124

then it partly represents objects of experience in a series so
extended as no experience can grasp, partly even (with a
view to complete the series) it seeks entirely beyond it
nonmena, to which it can attach that chain, and so, having
at last escaped from the conditions of experience, make its
attitude as it were final. These are then the transcendental
Ideas, which, though according to the true but hidden ends
of the natural determination of our reason, they may aim
not at extravagant concepts, but at unbounded extension of
empirical use, yet seduce \ablocken\ the understanding by
an unavoidable illusion to a transcendent use, which, though
deceitful, cannot be restrained within the bounds of experi
ence by any resolution, but only by scientific instruction
and with much difficulty.

I. The Psychological Idea.'1

§ 46. It has been long since observed, that in all sub
stances the proper subject, that which remains after all the
accidents (as predicates) are abstracted, consequently that
which is itself substantial, is unknown, and various com
plaints have been [124] made concerning these limits to
our knowledge. But we must take care to observe, that
the human understanding is not to be blamed for its inability
to know the substance of things, that is, to determine it by
itself, but rather for requiring to cognise a mere Idea de-
terminately, like a given object. Pure reason requires us
to seek for every predicate of a thing its proper subject, and
for this subject, which is itself necessarily nothing but a
predicate, its subject, and so on indefinitely (or as far as we
can reach). But hence it follows, that we must not hold
anything, at which we can arrive, to be an ultimate subject,

1 Vide Kritik, p. 237 sqq., and Appendix C to this volume. M.

124-125] THE DIALECTIC OF PURE REASON 97

and that substance itself never can be thought by our
understanding, however deep we may penetrate, even if all
nature were unveiled to us. For the specific nature of our
understanding consists in thinking everything discursively,
that is, representing it by_con£££ts, and so by ^mere^predi-
-caiej^to which therefore the absolute subject must always
be wanting. Hence all the real properties, by which we
cognise bodies, are mere accidents, not excepting impene
trability, which we can only represent to ourselves as the
effect of a power of which the subject is unknown to us.

Now we appear to have this substance in the conscious
ness of ourselves (in the thinking subject), and indeed in an
immediate intuition ; for all the predicates of an internal
sense refer to the ego, as [125] subject, and I cannot con
ceive myself as the predicate of any other subject. Hence
completeness in the reference of the given concepts as
predicates to a subject — not merely an Idea, but an object
— that is, the absolute subject itself, seems to be given in
experience. But this expectation is disappointed. For the
Ego is not a concept,1 but only the indication of the object
of the internal sense, so far as we cognise it by no further
predicate. Consequently it cannot be in itself a predicate
of any other thing ; but just as little can it be a determinate
concept of an absolute subject, but is, as in all other cases,
only the reference of the internal phenomena to their un
known subject. Yet this Idea (which serves very well, as a
regulative principle, totally to destroy all materialistic ex
planations of the internal phenomena of the soul) occasions

1 Were the representation of the apperception (the Ego) a concept, by
which anything could be thought, it could be used as a predicate of
other things or contain predicates in itself. But it is nothing more than
the feeling of an existence without the least definite notion [Begriff]
and is only the representation of that, to which all thinking stands in
relation (relatione accidentis. )

II H

98 PROLEGOMENA TO METAPHYSIC [125-127

by a very natural misunderstanding a very specious argu
ment, which, from this supposed cognition of the substance
of our thinking being, infers its nature, so far as the know
ledge of it falls quite without the complex of experience.

[126] §4 7. But though this thinking self (the soul)
should be termed substance, as being the ultimate subject
of thinking which cannot be further represented as the
predicate of another thing ; yet this concept remains quite
empty and without results, if permanence — the quality
which renders the concept of substances in experience fruit
ful — cannot be deduced from it.

But permanence can never be proved from the concept
of a substance, as a thing per se, but for the purposes of
experience only. This is sufficiently shown by the first
Analogy of Experience,1 and whoever will not yield to this
proof may try for himself whether he can succeed in proving,
from the concept of a subject which does not exist itself as
the predicate of another thing, that its existence is thoroughly
permanent, and that it cannot either in itself or by any
natural cause originate or be annihilated. These synthetical
a priori propositions can never be proved in themselves, but
only in reference to things as objects of possible experience.

§ 48. If therefore from the concept of the soul as a sub
stance, we would infer its permanence, this can hold good
as regards possible experience only, not [of the soul] as a
thing in itself and beyond all possible experience. But life
is the subjective [127] condition of all our possible ex
perience, consequently we can only infer the permanence of
the soul in life ; for the death of man is the end of all ex
perience which concerns the soul as an object of experience,
except the contrary be proved, which is the very question
in hand. The permanence of the soul can therefore only
1 Cf. Kritik, p. 136 sqq.

127-128] THE DIALECTIC OF PURE REASON 99

be proved where everybody grants it, during the life of man.
But we cannot [establish it], as we desire to do, after death ;
and for this general reason, that the concept of substance,
so far as it is to be considered necessarily combined with
the concept of permanence, can be so combined only
according to principles of possible experience, and therefore
for the purposes of experience only.1

[128] § 49. That something actual without us not only
corresponds, but must correspond, to our external percep
tions, can likewise be proved not as a connexion of things
in themselves, but for the purpose of experience. This
means : — that it certainly admits of proof that there is
something empirical, i.e. [existing] as phenomenon in space
without us ; for we have nothing to do with other objects
than those which belong to possible experience ; because

1 It is indeed very remarkable, how carelessly metaphysicians have
always passed over the principle of the permanence of substances with
out ever attempting a proof of it ; doubtless because they found them
selves abandoned by all proofs as soon as they began to deal with the
concept of substance. Common sense, which felt distinctly that with
out this presupposition no union of perceptions in experience is possible,
supplied the want by a postulate ; for from experience itself it never could
derive such a principle, partly because substances cannot be so traced
in all their alterations and dissolutions, that the matter can always be
found undiminished, partly because the principle contains necessity,
which is always the sign of an a priori principle. People then boldly
applied this postulate to the concept of soul as a substance, and concluded
a necessary continuance of the soul after the death of man (especially as
the simplicity of this substance, which is inferred from the indivisibility
of consciousness, secured it from destruction by dissolution). Had they
found the genuine source of this principle — a discovery which requires
deeper researches than they were ever inclined to make — they would
have seen, that the law of the permanence of substances has place for
the purposes of experience only, and hence can hold good of things, so
far as they are to be cognised and conjoined with others in experience,
but never independently of all possible experience, and consequently
cannot hold good of the soul after death.

ioo PROLEGOMENA TO METAPHYSIC [128-129

objects, which cannot be given us in any experience, are
nothing to us. That which is intuited in space, is empiric
ally without [outside] me, and space, together with all the
I phenomena which it contains, belongs to the representations,
1 whose connexion according to laws of experience proves
1 their objective truth, just as the connexion of the phenomena
of the internal sense proves the actuality of my soul (as an
object of the internal sense). I am therefore conscious by
means of external experience of the actuality of bodies, as
external [129] phenomena in space, in the same manner as
I am, by means of the internal experience, of the existence
of my soul in time.1 For this (soul) I only cognise as an
object of the internal sense by phenomena that constitute
an internal state, and of which the being per se, which forms
the basis of these phenomena, is unknown to me. Cartesian
idealism therefore does nothing but distinguish external ex
perience from dreaming ; and the conformity to law (as a
criterion of its truth) of the former, from the irregularity and
the false illusion of the latter. In both it presupposes space
and time as conditions of the existence of objects, and it
only inquires whether the objects of the external senses,
which we when awake put in space, are as actually to be
found in it, as the object of the internal sense, the soul, is
in time; that is, whether experience carries with it sure
criteria to distinguish it from imagination. Now this doubt
may easily be removed, and we always do remove it in
common life by investigating the connexion of phenomena
in both [space and time] according to universal laws of ex-

1 It is to be observed that Kant here places his refutation of Cartesian
idealism in the place which it held in the First Edition of the Kritik.
In the Second Edition it was transferred to an earlier, and I think a
better, place, in connexion with the Postulates of Empirical Thought.
M.

129-131] THE DIALECTIC OF PURE REASON 101

perience, and we cannot doubt, when [130] the representa
tion of external things thoroughly agrees therewith, that
they constitute truthful experience. Material idealism, in
which phenomena are considered as such only according to
their connexion in experience, may accordingly be very
easily refuted ; and it is just as sure an experience, that bodies
exist without us (in space), as that I myself exist according
to the representation of the internal sense (in time) : for the
notion ivithout [outside] us, only signifies existence in space.
However as the Ego in the proposition, ' I am, means not
only the object of internal intuition (in time), but the sub
ject of consciousness, just as body means not only external
intuition (in space), but the thing in itself , which is the basis
of this phenomenon ; [as this is the case] the question,
whether bodies (as phenomena of the external sense) exist
as bodies apart from my thoughts^ may without any hesita
tion be denied in nature. But the question, whether I my
self as a phenomenon of the internal sense (the soul according
to empirical psychology) exist apart from my faculty of re
presentation in time, is an exactly similar inquiry, and must
likewise be answered in the negative. And in this manner
everything, when it is reduced to its true meaning, is decided
and certain. The formal (which I have also called tran
scendental) actually abolishes the material, or Cartesian,
Idealism. For if space be nothing but a form of my
sensibility, it is as a [131] representation in me just as
actual as I myself am, and nothing but the empirical truth
of the representations in it remains for consideration. But,
if this is not the case, if space and the phenomena in it
are something existing out of us, then all the criteria of
experience beyond our perception can never prove the
actuality of these objects without us.1

1 The foregoing paragraph is an excellent commentary on the Refuta-

102 PROLEGOMENA TO METAPHYSIC [131-132

II. The Cosmological Ideal

§ 50. This product of pure Reason in its transcendent
use is its most remarkable phenomenon, and the most
powerful of all means of rousing philosophy from its dog
matic slumber, and of exciting it to undertake the arduous
task of the Kritik of the Reason itself.

I term this Idea cosmological, because it only takes its
objects from the sensible world, and does not use any
other than those whose object is given to sense, con
sequently is so far at home [immanent], not transcendent,
and therefore so far not an Idea; whereas, to conceive the
soul as a simple substance, already 'means to conceive
such an object (the Simple) [132] as cannot be presented to
the senses. Yet the cosmological Idea extends the con
nexion of the conditioned with its condition (whether the
connexion is mathematical or dynamical) so far, that ex
perience never can keep up with it. It is therefore with
regard to this point always an Idea, whose object never
can be adequately given in any experience.

§ 5 1. In the first place, the use of a system of categories
becomes here so obvious and unmistakable, that even if
there were not several other proofs of it, this alone would
sufficiently prove it indispensable in the system of pure
reason. There are only four such transcendent Ideas, as
there are so many classes of categories ; in each of which,
however, they refer only to the absolute completeness of
the series of the conditions for a given conditioned. And
conformably to these cosmological Ideas there are only

tion of (Cartesian, not Berkleian) idealism in the Second Edition of the
Kritik, and corroborates my assertion that it has been absurdly miscon
ceived. It is not creditable to German Kantians that they have pro
pagated this blunder. M.
1 Cf. Kritik, p. 256.

132-133] THE DIALECTIC OF PURE REASON 103

four kinds of dialectical assertions of pure Reason, which,
as they are dialectical, thereby prove, that to each of them,
on equally specious principles of pure reason, a contra
dictory assertion stands opposed. As all the metaphysical
art of the most subtile distinction cannot prevent this
opposition, it compels the philosopher to recur to the first
sources of pure reason itself. This Antinomy, not arbitrarily
invented, but founded in the nature of human reason, and
hence unavoidable and never ceasing, contains the following
four theses together with their antitheses :

[i33] i.

Thesis.

The World has, as to Time and Space, a Beginning (Bounds).

Antithesis.
The World is, as to Time and Space, infinite.

2.

Thesis.
Every thing in the World consists of simple [parts].

Antithesis.
There is nothing simple, but every thing is composite.

3-

Thesis.

There are in the World Causes [acting] through Freedom
[Liberty].

Antithesis.
There is no Liberty, but all is Nature.

io j PROLEGOMENA TO METAPHYSIC [133- 134

4-

Thesis.

In the Series of the World-Causes there is some necessary
Being.

Antithesis.

There is Nothing necessary in the World, but in this Series
All is contingent.

[134] § 52. a. Here we have the most singular pheno
menon of human reason, no other instance of which can
be shown in any other use [of reason].- If we, as is
commonly done, represent to ourselves the phenomena of
the sensible world as things in themselves, — if we assume
the principles of their combination as principles universally
valid of things in themselves and not merely of experience
(as is usually, nay without our Kritik, unavoidably done),
—there arises an unexpected conflict, which never can be
removed in the common dogmatical way ; because the
thesis, as well as the antithesis, can be shown by equally
clear, evident, and irresistible proofs — for I pledge myself
as to the correctness of all these proofs — and reason
therefore perceives that it is divided with itself, a state at
which the sceptic rejoices, but which must cause the critical
philosopher reflection and uneasiness.

§ 52. b. We may make divers blunders in Metaphysic
without any fear of being detected in falsehood. For we
never can be refuted by experience if we but avoid self-
contradiction, which in synthetical, though purely invented
propositions, may be done whenever the concepts, which
we connect, are mere Ideas, that cannot be given (as to
their whole content) in experience. For how can we make
out by experience, whether the world is from eternity or

134-136] THE DIALECTIC OF TORE REASON 105

had a beginning, whether matter is infinitely divisible or
consists of simple parts? Such [135] concepts cannot be
given in any experience, however great, and consequently
the falsehood either of the positive or the negative proposi
tion cannot be discovered by this test.

The only possible case, in which Reason reveals unin
tentionally its secret Dialectic, which it falsely announces
as Dogmatic, is when it grounds an assertion upon a
universally admitted principle, and from another equally
admitted infers, with the greatest accuracy of inference, the
exact contrary. This is actually here the case with regard
to four natural Ideas of Reason, whence four assertions on
the one side, and as many counter -assertions on the other
arise, each strictly following from universally-acknowledged
principles. Thus the dialectical illusion of pure Reason
appears in the use of these principles, [an illusion] which
must otherwise be for ever concealed.

This is therefore a decisive experiment, which must
necessarily expose any error lying hidden in the assump
tions of Reason.1 Contradictory propo- [136] sitions cannot
both be false, except the concept, which is the subject of
both, is self- contradictory ; for example, the propositions,
* a square circle is round, and a square circle is not round,'
are both false. For, as to the former it is false, that the
circle is round, because it is quadrangular ; and it is

1 I therefore request the critical reader to make this Antinomy his
chief study, because nature itself seems to have established it with a
view to stagger reason in its daring pretentions, and to force it to self-
examination. For every proof, which I have given, as well of the
thesis as of the antithesis, I undertake to be responsible, and thereby to
show the certainty of the inevitable Antinomy of reason. As soon as
the reader is brought by this curious phenomenon to recur to the proof
of the presumption upon which it rests, he will feel himself constrained
to investigate the first foundation of all the cognition of pure reason with
me more thoroughly.

io6 PROLEGOMENA TO METAPHYSIC [136-137

likewise false, that it is not round, that is, angular, because
it is a circle. For the logical mark of the impossibility of
a concept consists in this, that if we presuppose it, two
contradictory propositions both become false ; consequently,
as no middle between them is conceivable, nothing at all is
thought by that concept.

§ 52. c. The first two Antinomies, which I call mathe
matical, because they are concerned with the addition or
division of the homogeneous, are founded on such a self-
contradictory concept ; and hence I explain how it happens,
that the Thesis in both, as well as the Antithesis [addition
and subdivision] is false.

When I speak of objects in time and in space, it is not
of things in themselves, of which I know nothing, but of
things as phenomena, that is, of experience, as the particular
way of cognising objects which is vouchsafed to man.
\ Accordingly [137] I must not say of what I think in time
or in space, that in itself, and beyond [outside] these my
thoughts, it exists in space and in time ; for in that case I
should contradict myself; l^ca_u£e_space^m^Jiipe,_tp^ether
with -lfoe"^henomena-Uii_^theiTiJL_are nothing existing in
themselves and without [outside] my representations., but
are themselves only modes of representation, and it is
palpably contradictory to say, that a mere mode of repre
sentation exists without our representation. Objects of the
senses therefore exist only in experience ; whereas to give
them a self- subsisting existence apart from experience or
before it, is merely to represent to ourselves, that experience
actually exists apart from experience or before it.

Now if I inquire after the quantity of the world, as to
space and time, it is equally impossible, as regards all my
notions, to declare it infinite, or to declare it finite. For
neither assertion can be contained in experience, because

137-139] THE DIALECTIC OF PURE REASON 107

experience either of an infinite space, or of an infinite time
elapsed, or again, of the bounding of the world by a void
space or an antecedent void time, is impossible ; these are
only Ideas. This quantity of the world, which is determined
in either way, should therefore exist in the world per se apart
from all experience. But this contradicts the notion of a
world of sense, which is merely a complex of the phenomena
whose existence and connexion occur only in our repre- [138]
sentations, that is, in experience, since this latter is not a thing
per se, but is itself a mere mode of representation. Hence
it follows, that as the concept of an absolutely existing world
of sense is self-contradictory, the solution of the problem
concerning its quantity, whether attempted affirmatively or
negatively, is always false.

The same holds good of the second Antinomy, which
relates to the division of phenomena. For these are mere
representations, and the parts exist merely in their representa
tion, consequently in the division, or in a possible experience
where they are given, and the division reaches only as far
as this latter reaches. To assume that a phenomenon, e.g.
that of body, contains in itself before all experience all the
parts, which any possible experience can ever reach, is to
give a mere phenomenon, which can exist only in experience,
withal an existence previous to experience ; or to say, that
mere representations exist before they occur in our faculty of
representation, which assertion is self-contradictory, as also
every solution of our misunderstood problem, whether we
maintain, that bodies in themselves consist of an infinite
number of parts, or of a finite number of simple parts.

§ 5 3. In the first (the mathematical) class of Antinomies
the falsehood of the assumption consists in representing
that what is self-contradictory (a phenomenon as a thing
per se) can be united in one [139] concept. But, as to the

io8 PROLEGOMENA TO METAPHYSIC [139-140

second (the dynamical) class of Antinomies, the falsehood
of the representation consists in representing as contradictory
what can be united; so that, as in the former case, the
opposed assertions are both false, in this case, on the other
hand, where they are opposed to one another by mere
misunderstanding, they may both be true.

For mathematical connexion necessarily presupposes
homogeneity of what is connected (in the concept of
quantity), but this is by no means requisite in the
dynamical. When the quantum of wriat is extended is in
question, all the parts must be homogeneous with one
another and with the whole ; whereas, in the connexion of
cause and effect, homogeneity may indeed likewise be
found, but is not necessary ; for the concept of causality
(by means of which something is posited through something
else quite distinct from it), at all events, does not require it.

If the objects of the sensuous world are taken for things
in themselves, and the above laws of nature for the laws of
things in themselves, the contradiction would be unavoid
able. So also, if the subject of freedom is, like other
objects, represented as mere phenomenon, the contradiction
is just as unavoidable, for the same predicate is at once
affirmed and denied of the same kind of object in the same
sense. But if natural necessity is referred [140] merely to
phenomena, and freedom merely to things in themselves,
no contradiction arises, if we at once assume, or admit both
kinds of causality, however difficult or impossible it may be
to make the latter kind conceivable.

In the phenomenon every effect is an event, or some
thing that happens in time; it must, according to the
universal law of nature, be preceded by a determination of
the causality (or state) of its cause, which follows according
to a constant law. But this determination of the cause to

140-141] THE DIALECTIC OF PURE REASON 109

[produce] causality must likewise be something that happens,
or takes place ; the cause must have begun to act, otherwise
no succession between it and the effect could be conceived.
Otherwise the effect, as well as the causality of the cause,
would have always existed. Therefore the determination
of the cause to act must also have originated among
phenomena, and must consequently, as well as its effect, be
an event, which must again have its cause, and so on ; hence
natural necessity must be the condition, on which effective
causes are determined. Whereas if freedom is to be a
property of certain causes of phenomena, it must, as regards
these, which are events, be a faculty of beginning them
from itself (sponte], that is, without the causality of the
cause itself beginning, and hence without requiring any
other ground to determine its beginning. But then the
cause, as to its causality, must not rank under time-determina-
[141] tions of its state, that is, not be a phenomenon, and
must be considered a thing per se, and its effects only as
phenomena.1 If we can think such an influence of the

1 The Idea of freedom occurs only in the relation of the intellectual,
as cause, to the phenomenon, as effect. Hence we cannot attribute
freedom to matter in regard to the incessant action by which it fills its
space, though this action takes place from an internal principle. We
can likewise find no notion of freedom suitable to pure rational beings,
for instance, to God, so far as His action is immanent. For His action,
though independent of external determining causes, is determined in
His eternal reason, that is, in the divine nature. It is only, if something
is to begin by an action, and so the effect occurs in the sequence of time,
or in the world of sense (e.g. the beginning of the world), that we can
put the question, whether the causality of the cause must likewise itself
begin, or whether the cause can originate an effect without its causality
itself beginning. In the former case the concept of this causality is a
concept of natural necessity, in the latter, that of freedom. From this
the reader will see, that, as I explained freedom to be the faculty of
beginning an event spontaneously, I have exactly hit the notion which
is the problem of Metaphysic.

i io PROLEGOMENA TO METAPHYSIC [141-142

things of understanding \Verstandeswesen\ on phenomena
without contradiction, then natural necessity will attach to
all connexion of cause and effect in the sensuous world, but,

(on the other hand, freedom can be granted to such cause,
as is itself not a phenomenon (though the basis of one).
Nature therefore and freedom can without contradiction be
attributed to the very same thing, [142] but in different
relations — on one side as a phenomenon, on the other as
a thing per se.

We have in us a faculty, which not only stands in con
nexion with its subjective determining grounds, that are the
natural causes of its actions, and is so far the faculty of a
being that itself belongs to phenomena : but is [also a
faculty] referred to objective grounds, that are only ideas,
*so far as they can determine this faculty, a connexion which
is expressed by the word ought. This faculty is called
Reason, and, so far as we consider a being (man) entirely
according to this objectively determinable reason, he cannot
be considered as a being of sense, but this property is that
of a thing per se, of which we cannot comprehend the
possibility — I mean how the ought (which however has
never yet taken place) should determine its activity, and can
become the cause of actions, whose effect is a phenomenon
in the sensible world. Yet the causality of Reason would
be freedom with regard to the effects in the sensuous world,
so far as we can consider objective grounds, which are them
selves Ideas, as determining in regard to it. For its action
in that case would not depend upon subjective conditions,
consequently not upon those of time, and of course not
upon the law of nature, which serves to determine them,
because grounds of reason give to actions the rule universally,
according to principles, without the influence of the circum
stances of either time or place.

143-144] THE DIALECTIC OF PURE REASON in

[143] What I adduce here is merely meant as an example
to make the thing intelligible, and does not necessarily belong
to our problem, which must be decided from mere concepts,
independently of the properties which we meet in the actual
world.

Now I may say without contradiction : that all the actions
of rational beings, so far as they are phenomena (occurring
in any experience), are subject to the necessity of nature ;
but the same actions, as regards merely the rational subject
and its faculty of acting according to mere Reason, are free.
For what is required for the necessity of nature ? Nothing
farther than the determinability of every event in the world
of sense according to constant laws, that is, a reference to
cause in the phenomenon ; in this process the thing in itself
at its basis and its causality remain unknown. But I say,
that the law of nature remains, whether the rational being is
the cause oLlhe ejects^jn^the_se^uous world from reason,
that is, throughjreedom, or whether it does not determine
them on grounds of reason. For, if the former is the case,
the action is performed according to Maxims, the effect of
which as phenomenon is always conformable to constant
laws ; if the latter is the case, and the action not performed
on principles of Reason, it is subjected to the empirical
laws of the sensibility, and in both cases the effects are con
nected according to constant laws ; more than this we do
not require or know concerning [144] natural necessity. But
in the former case reason is the cause of these laws of nature,
and therefore free ; in the latter the effects follow according
to mere natural laws of sensibility, because reason does not
influence it ; but reason itself is not determined on that
account by the sensibility, and is therefore free in this case
too. Freedom is therefore no hindrance to natural law in
phenomena, neither does this law interfere with the freedom

ii2 PROLEGOMENA TO METAPHYSIC [144-145

of the practical use of Reason, which is connected with
things in themselves, as determining grounds.

And thus we rescue practical freedom, or that in which
Reason has causality according to objectively determining
grounds, and do not curtail natural necessity in the least
with regard to the very same effects, as phenomena. The
same remarks may be serviceable for the illustration of what
we had to say concerning transcendental freedom and its
union with natural necessity (in the same subject, but not
taken in the same reference). For, as to this, every be
ginning of the action of a being from objective causes
regarded as determining grounds, is always a first beginning,
though the same action is in the series of phenomena only
a subaltern beginning, which must be preceded by a state of
the cause, which determines it, and is itself determined in
the same manner by another immediately preceding. Thus
i we are able, in rational beings, or in beings generally, so far
as their causality is determined in them [145] as things per
se, to imagine a faculty of beginning from itself a series of
states, without falling into contradiction with the laws of
nature. For the,relation of the action to objectiye_grQunds
of reason is not a time-relation ; in this case that which
determines the causality does not precede in time the action,
because such determining grounds represent not a reference
to objects of sense, e.g. to causes in the phenomenon, but
[they represent] determining causes, as things per se, which
do not rank under conditions of time. And in this way the
action, with regard to the causality of reason, can be con
sidered as a first beginning in respect to the series of
phenomena, and yet also as a merely subordinate beginning.
We may therefore consider it (without contradiction) in the
former aspect as free, but in the latter (as it is merely
phenomenon) as subject to natural necessity.

145-146] THE DIALECTIC OF PURE REASON 113

As to \hsfourth Antinomy, it is solved in the same way
as the conflict of reason with itself in the third. For, pro
vided the cause in the phenomenon is distinguished from the!
cause of the phenomena (so far as it can be thought as a thing*
-ber se\ both propositions are perfectly reconcilable : the one,
that there is nowhere in the sensuous world a cause
(according to similar laws of causality), whose existence is
absolutely necessary ; the other, that this world is neverthe
less connected with a Necessary Being as its cause (but of
another kind and according to [146] another law). The
incompatibility of these propositions entirely rests upon the
mistake of extending what is valid merely of phenomena^ to
things inthemselves, and in general confusing both in one
concept.

§ 54. This is the arrangement and this the solution of
the whole Antinomy, in which reason finds itself involved
in the application of its principles to the sensible world, the
former of which alone (the mere arrangement) would be of
considerable use in promoting the knowledge of human
reason, even though the solution failed to fully satisfy the
reader, who has here to combat a natural illusion, which has
been but recently exposed to him, and which he had hitherto
always regarded as true. For one result at least is unavoid
able. As it is quite impossible to prevent this conflict of
reason with itself — so long as the objects of the sensible
world are taken for things in themselves, and not for mere
phenomena, which they are in fact — the reader is thereby
compelled to examine over again the deduction of all our a
priori cognition and the proof which I have given of my
deduction in order to come to a decision on the question.
This is all I require at present ; for when in this occupation
he shall have thought himself far enough into the nature
of pure reason, the only notions by which the solution of
ii i

ii4 PROLEGOMENA TO METAPHYSIC [146-148

the conflict of reason is possible, will become sufficiently
familiar to him. Without this preparation I cannot [147]
expect a hasty assent even from the most attentive reader.

III. The Theological Idea.1

§ 55. The third transcendental Idea, which affords
matter for the most important, but, if pursued only specula-
tively, transcendent and thereby dialectical use of Reason,
is the Ideal of pure Reason. Reason in this case does not,
as with the psychological and the cosmological Ideas, begin
from experience, and err by exaggerating its grounds^ in
striving to attain, if possible, the absolute completeness of
their series. It rather breaks totally with experience, and
from mere concepts of what constitutes the absolute com
pleteness of a thing in general, consequently by means of
the Idea of a most perfect primal Being, it proceeds to
determine the possibility and therefore the actuality of all
other things. And so the mere presupposition of a Being,
who is conceived not in the series of experience, yet for the
purposes of experience — for the sake of comprehending its
connexion, order, and unity — that is, the Idea, is more easily
distinguished from the concept of the understanding here,
than in the former cases. Hence we can easily expose the
dialectical illusion which arises from our making the subject
ive conditions of our thinking objective conditions [148] of
things themselves, and [so holding] a necessary hypothesis
for the satisfaction of our reason to be a dogma. As the
observations of the Kritik on the pretensions of transcend
ental theology are intelligible, clear, and decisive, I have
nothing more to add on the subject.

1 Cf. Kritik, p. 350 sqq.

148-149] THE DIALECTIC OF PURE REASON 115

General Remark on the Transcendental Ideas.

§ 56. The objects, which are given us by experience, are
in many respects incomprehensible, and many questions, to
which the law of nature leads us, when carried beyond a
certain point (though quite conformably to the laws of
nature), admit of no answer ; as for example the question :
why substances attract one another? But if we entirely
quit nature, or in pursuing its combinations, exceed all
possible experience, and so involve ourselves in mere Ideas,
we cannot then say that the object is incomprehensible, and
that the nature of things proposes to us insoluble problems.
For we are not then concerned with nature or in general
with given objects, but with concepts, which have their
origin merely in our reason, and with mere creatures of
thought. As regards these all the problems that arise from
our notions of them must be solved, because of course reason
can and must give a full account of its own procedure.1 As
the psycho- [149] logical, cosmological, and theological Ideas
are nothing but pure concepts of Reason, which cannot be
given in any experience, the questions which reason asks us
about them are put to us not by the objects, but by mere
maxims of our reason for the sake of its own satisfaction.

1 And therefore Platner in his Aphorisms acutely says (§§ 728, 729),
'If reason be a criterion, no concept, which is incomprehensible to human
reason, can be possible. Incomprehensibility has place in what is actual
only. Here incomprehensibility arises from the insufficiency of the
acquired Ideas. ' It therefore only sounds paradoxical, but is otherwise
not strange to say, that in nature there is much incomprehensible (e.g.
the faculty of generation) but if we mount still higher, and even go
beyond nature, everything again becomes comprehensible ; for we then
quit entirely the objects, which can be given us, and occupy ourselves
merely about Ideas, in which occupation we can easily comprehend the
law that reason prescribes by them to the understanding for its use in
experience, because the law is the reason's own production.

ii6 PROLEGOMENA TO METAPHYSIC [149-150

They must collectively be capable of complete answers,
which is done by showing that they are principles which
bring our use of the understanding into thorough agreement,
completeness, and synthetical unity, and that they so far
hold good of experience only, but of experience as &jMkole_-
But though an absolute whole of experience is impossible,
yet the Idea of a whole of cognition according to principles
must above all things afford our knowledge a particular sort
of unity, that of a system, without which it is nothing but
patchwork, and cannot be used for the highest end (which
can only be the systemf-atising] of all ends) — I [150] do
not here mean only the practical, but also the highest end
of the speculative use of reason.

The transcendental Ideas therefore express the peculiar
destination of reason as a principle of systematic unity in
the use of the understanding. Yet [we are apt to consider]
this unity of the mode of cognition as attached to the object
of cognition, if we regard that which is merely regulative
to be constitutive, and if we persuade ourselves, that we can
by means of these Ideas enlarge our cognition transcend-
ently, or far beyond all possible experience. But [if we
do] so — as this unity only serves to render experience within
itself as nearly complete as possible, that is, to limit its pro
gress by nothing that cannot belong to experience — it is
a mere misunderstanding in our estimate of the proper
destination of our reason and of its principles, a Dialectic,
which both confuses the empirical use of reason, and also
sets reason at variance with itself.

CONCLUSION

On the determination of the Bounds of Pure Reason
§ 57. After all the very cogent proofs already adduced, it

150-152] THE BOUNDS OF PURE REASON 117

were absurd for us to hope to know more of any object,
than belongs to the possible experience of it, or to lay claim
to the least atom of knowledge about anything not assumed
to be an object of possible experience, which would deter-
[151] mine it according to the constitution it has in itself.
For how could we compass this determination, as time,
space, and the Categories, and still more all the concepts
formed by empirical intuition or perception in the sensible
world, have and can have no other use, than to make experi
ence possible. And if this condition is not imposed on the
pure concepts of the understanding, they do not determine
any object, and have no meaning whatever.

But it would be on the other hand a still greater
absurdity if we conceded no things per se, or set up our
experience for the only possible mode of knowing things,
our intuition in space and in time for the only possible
intuition, and our discursive understanding for the archetype
"of every possible understanding ; in fact if we wished to have
the principles of the possibility of experience considered
universal conditions of things in themselves.

Our principles, which limit the use of reason merely to
possible experience, might in this way become transcendent f,
and the limits of our reason be set up as limits of the
possibility of things themselves • (as Hume's dialogues may
illustrate), if a careful Kritik did not guard the bounds of
our reason with respect to its empirical use, and set a limit
to its pretensions. Scepticism originally arose from meta-
physic and its licentious dialectic. At first it might, merely
to favour the empirical use of [152] reason, announce every
thing that transcends this use as worthless and deceitful ; but
by and by, when it was perceived that the very same
principles that are used in experience, insensibly, and
apparently with the same right, led still further than experi-

n8 PROLEGOMENA TO METAPHYSIC [152-153

ence extends, then men began to doubt even the propositions
of experience. But here there is no danger ; for sound sense
will doubtless always assert its rights. A certain confusion,
however, arose in science which cannot determine how far
reason is to be trusted, and why only so far and no further,
and this confusion can only be cleared up and all future re
lapses obviated by a formal determination, on principle, of
the boundary of the use of our reason.

We cannot indeed, beyond all possible experience, form
a determinate notion of what things in themselves may be.
Yet we are not at liberty to abstain entirely from inquiring
into them ; for experience never satisfies reason fully, but in
answering questions, refers us further and further back, and
leaves us dissatisfied with regard to their complete solution.
This any one may gather from the Dialectic of pure reason,
which therefore has its good subjective grounds. If we can
advance, as regards the nature of our soul, as far as a clear
consciousness of the subject, and the conviction, that its
phenomena cannot be materialistically explained, who can
refrain from asking what the soul [153] really \eigentlicJi\
is, and, if no concept of experience suffices for the purpose,
from accounting for it by a concept of Reason (that of a
simple immaterial being), though we cannot by any means
prove its objective reality? Who can satisfy himself with
mere empirical knowledge in all the cosmological questions
of the duration and of the quantity of the world, of freedom
or of natural necessity, as every answer given on principles
of experience begets a fresh question, which likewise requires
its answer, and thereby clearly shows the insufficiency of all
physical modes of explanation to satisfy reason ? Finally,
who is there that does not see, in the thorough contingency
and dependence of all his thoughts and assumptions on mere
principles of experience, the impossibility of stopping there ?

153-154! THE BOUNDS OF PURE REASON 119

And who does not feel himself compelled, notwithstanding
all interdictions against losing himself in transcendent Ideas,
to seek tranquillity and contentment beyond all the concepts
which he can vindicate by experience, in the concept of a
single Being ? The possibility indeed of this Idea in itself,
we cannot conceive, but at the same time we cannot refute
it, because it relates to a mere being of the understanding,
and without it reason must needs remain for ever dis
satisfied.

Bounds (in extended beings) always presuppose a space
existing outside a certain determinate place, and inclosing it ;
limits do not require this, [154] but are mere negations, which
affect a quantity, so far as it is not absolutely complete.
But our reason, as it were, sees a space around it for the
cognition of things in themselves, though it (reason) never
can have determinate notions of them, and is limited to
phenomena only.

As long as the cognition of reason is homogeneous,
determinate bounds to it are inconceivable. In mathematic
and in natural philosophy human reason admits of limits,
but not of bounds, viz. that something indeed lies without
it, at which it can never arrive, but not that it will at
any point find completion in its internal progress. The
enlarging of our views in mathematic, and the possibility
of new discoveries, are infinite ; and the same is the case
with the discovery of new properties of nature, of new powers
and laws, by continued experience and its rational combina
tion. But limits cannot be mistaken here, for mathematic
refers to phenomena only, and what cannot be an object of
sensuous intuition, such as the concepts of metaphysic and
of morals, lies entirely without its sphere, and it can never
lead to them ; neither does it require them. It is therefore
not a continual progress and an approximation towards these

120 PROLEGOMENA TO METAPHYSIC [154-156

sciences, and there is not, as it were, any point or line of
contact. Natural philosophy will never discover to us the
internal constitution of things, which is not phenomenon,
yet can serve as the ultimate ground of [155] explanation of
phenomena ; but that science does not require this for its
physical explanations. Nay even if such grounds should be
offered from other sources (for instance, the influence of
immaterial beings), they must be rejected and not used
in the progress of its explanations. For these explana
tions must only be grounded upon that which as an
object of sense can belong to experience, and be brought
into connexion with our actual perceptions and empirical
laws.

But Metaphysic leads us towards bounds in the dialectical
attempts of pure reason (not undertaken arbitrarily or
wantonly, but excited by the nature of reason itself). And
the transcendental Ideas, as they do not admit of evasion,
and are never capable of realisation, serve to point out to us
actually not only the bounds of the pure use of reason, but
also the way to determine them. Such is the end and the
use of this natural predisposition of our reason, which has
brought forth Metaphysic as its pet, whose generation, like
every other in the world, is not to be ascribed to blind
chance, but to an original germ, wisely organised for great
ends. For Metaphysic, in its fundamental features, perhaps
more than any other science, is placed in us by nature itself,
and cannot be considered the production of a voluntary
choice or a casual enlargement in the progress of experience
from which it is quite distinct.

[156] Reason finds of itself no satisfaction by all its con
cepts and laws of the understanding, which suffice for
empirical use, or withm the sensible world, as ever-recurring
questions deprive us of all hope of their complete solution.

156-157! THE BOUNDS OF PURE REASON 121

The transcendental Ideas, which have that completion in
view, are "such problems of Reason. But it sees clearly,
that the sensuous world cannot contain this completion,
neither consequently can all the concepts, which serve
merely for understanding the world of sense, such as space
and time, and whatever we have adduced under the name
of pure concepts of the understanding. The sensuous world
is nothing but a chain of phenomena connected according
to universal laws ; it has therefore no subsistence by itself; it
is not the thing in itself, and consequently must point to
that which contains the basis of this experience, to beings
which cannot be cognised merely as phenomena, but as
things per se. In the cognition of them alone reason can
hope to satisfy its desire of completeness in proceeding from
the conditioned to its conditions.

We have indicated (§§ 33, 34) the limits of reason with
regard to all cognition of mere creatures of thought. Now
only — since the transcendental Ideas compel us to approach
them, and so have led us, as it were, only to the contact of
the full space (of experience) with the void (of which we
can know nothing, noumend) — now only we can [157] deter
mine the bounds of pure reason. For in all bounds there
is something positive (e.g., a surface is the boundary of
corporeal space, and is therefore itself a space, a line is a
space, which is the boundary of the surface, a point the
boundary of the line, but yet always a place in space),
whereas limits contain mere negations. The limits pointed
out in those paragraphs are not enough after we have dis
covered that beyond them there still lies something (though
we can never cognise what it is in itself). For the question
now is, What is the attitude of our reason in this connexion
of what we know with what we do not, and never shall, know ?
This is an actual connexion of a known thing with one quite

122 PROLEGOMENA TO METAPIIYSIC [157-158

unknown (and which will always remain so), and though
what is unknown should not become the least more known
— which we cannot even hope — yet the notion of this con
nexion must be definite, and capable of being rendered
distinct.

We must therefore conceive an immaterial being, an
intelligible world \Verstandeswelf^ and a Supreme Being
(mere noumena\ because in them only, as things in them
selves, Reason finds that completion and satisfaction, which
it never can hope for in the derivation of phenomena from
their homogeneous grounds, and because these actually
refer to something distinct from them (and totally hetero
geneous), as phenomena always presuppose a thing [158]
per se, and therefore indicate it, whether we can know
more of it or not.

But as we can never cognise these beings of under
standing as they are/^ se, that is, determinately, yet must
assume them as regards the sensible world, and connect
them with it by reason, we are at least able to think this
connection by means of such concepts as express their
relation to the world of sense. Yet if we represent to
ourselves a being of the understanding by nothing but pure
concepts of the understanding, we then indeed represent
nothing determinate to ourselves, consequently our concept
has no signification ; but if we think it by properties
borrowed from the sensuous world, it is no longer a being
of understanding, but is conceived as a phenomenon, and
belongs to the sensible world. Let us take an instance
from the notion of the Supreme Being.

Our notion of the Deity \deistischer Begriff} is quite
a pure concept of Reason, but represents only a thing
containing all realities, without being able to determine
any one of them ; because for that purpose an example

158-160] THE BOUNDS OF PURE REASON 123

must be taken from the sensuous world, in which case we
should have an object of sense only, not something quite
heterogeneous, which cannot be such. For suppose I
attribute to the Supreme Being understanding, [159] for
instance ; I have no concept of an understanding other
than my own, one that must receive intuitions by the
senses, and which is occupied in bringing them under rules
of the unity of consciousness. Then the elements of my
concept would always lie in the phenomenon ; I should
however by the insufficiency of the phenomena be neces
sitated to go beyond them to the concept of a being which
neither depends upon phenomena, nor is bound up with
them as conditions of its determination. But if I separate
understanding from sensibility to obtain a pure under
standing, then nothing remains but the mere form of
thinking without intuition, by which form alone I can
cognise nothing determinate, and consequently no object.
For that purpose I must conceive another understanding,
which should intuite objects, but of which I have not the
least notion ; because the human understanding is dis
cursive, and can only cognise by means of general concepts.
And the very same difficulties arise if we attribute a will to
the Supreme Being ; for we have this concept only by
drawing it from our internal experience, and therefore from
our dependence for satisfaction upon objects whose existence
we require ; and so the notion rests upon sensibility, which
is totally repugnant to the pure concept of the Supreme
Being.

Hume's objections to deism are weak, and affect
[160] only the proofs, and not the deistical assertion itself.
But as regards theism, which depends on a stricter
determination of the Deist's merely transcendent concept
of the Supreme Being, they are very strong, and after [or

i24 PROLEGOMENA TO METAPHYSIC [160-161

according as] this concept is formed, in certain (in fact in
all common) cases irrefragable. Hume always insists, that
by the mere concept of an original being, to which we
apply only ontological predicates (eternity, omnipresence,
omnipotence), we think nothing determinate, and that
properties which can yield a concept in concrete must be
superadded ; that it is not enough to say, it is Cause, but
we must explain the nature of its causality, for example,
that of an understanding .and of a will. He then begins
his attacks on the assertion itself, theism, as he had pre
viously directed his battery only against the proofs of deism,
an attack which is not very dangerous in its consequences.
All his dangerous arguments refer to anthropomorphism,
which he holds to be inseparable from theism, and to
make it absurd in itself; but if the former be abandoned,
the latter must vanish with it, and nothing remain but
deism, of which nothing can come, which is of no value,
and which cannot serve as any foundation to religion or
morals. If this anthropomorphism were really unavoidable,
no proofs whatever of the existence of a Supreme Being,
even were they all granted, could determine for us the
[161] concept of this Being without involving us in con
tradictions.

If we connect with the command to avoid all tran
scendent judgments of pure reason, the command (which
apparently conflicts with it) to proceed to concepts that lie
beyond the field of its immanent (empirical) use, we
discover that both can subsist together, but exactly at the
boundary of all lawful use of reason. For this boundary
belongs as well to the field of experience, as to that of the
beings of thought, and we are thereby taught, as well, how
these so remarkable Ideas serve merely for marking the
bounds of human reason. [Thus we are told] on the one

161-163] THE BOUNDS OF PURE REASON 125

hand not to extend cognition of experience without bounds,
as if nothing but mere world remained for us to cognise,
and yet, on the other hand, not to transgress the bounds of
experience, and to think of judging about things beyond
them, as things in themselves.

But we stop at this boundary if we limit our judgment
merely to the relation which the world may have to a
Being whose very concept lies beyond all the knowledge
which we can attain within the world. For we then do
not attribute to the Supreme Being any of the properties
in themselves ; by which we represent objects of experience,
and thereby avoid dogmatic anthropomorphism; but we
attribute them to His relation to the world, and allow
ourselves a symbolical anthropomorphism, [162] which in
fact concerns language only, and not the object itself.

If I say that we are compelled to consider the world,
as if it were the work of a Supreme Understanding and
Will, I really say nothing more, than that a watch, a ship,
a regiment, bears the same relation to the watchmaker, the
shipbuilder, the commanding officer, as the world of sense
(or whatever constitutes the substratum of this complex of
phenomena) does to the Unknown, which I do not hereby
cognise as it is in itself, but as it is for me or in relation to
the world, of which I am a part.

§ 58. Such a cognition is analogical, which does not
signify, as is commonly understood, an imperfect similarity
of two things, but a perfect similarity of relations between
two quite dissimilar things.1 [163] By means of this

1 There is an analogy between the juridical relation of human actions*
and the mechanical relation of motive powers ; I never can do anything
to another man without giving him a right to do the same to me on the
same conditions ; as no body can act with its motive power on another
body without thereby occasioning the other to react equally against it.

126 PROLEGOMENA TO METAPHYSIC [163-164

analogy, however, there remains a concept of the Supreme
Being sufficiently determined for us, though we have left
out everything that could determine it absolutely or in itself ;
for we determine it as regards the world and as regards
ourselves, and more we do not require. The attacks which
Hume makes upon those who would determine this concept
absolutely, by taking the materials for so doing from them
selves and the world, do not affect us ; and he cannot object
to us, that we have nothing left if we give up the objective
anthropomorphism of the concept of the Supreme Being.

For let us assume at the outset (as Hume in his dia
logues makes Philo grant Cleanthes), as a necessary
hypothesis, the deistical concept of the First Being, in which
this Being is thought by the mere ontological predicates of
substance, of cause, etc. This must be done, because reason,
actuated in the sensible world by mere conditions, which
are themselves always conditional, cannot otherwise have
any satisfaction, and it therefore can be done without falling
into anthropomorphism (which transfers predicates from the
world of sense to a Being quite distinct from the world), as
those predicates [which we propose [164] to use] are mere
categories, which, though they do not give a determinate
concept of Him, yet give a concept not limited to any
conditions of sensibility. [Granting this then] nothing

Here right and motive power are quite dissimilar things, but in their
relation there is complete similarity. By means of such an analogy
I can obtain a notion of the relation of things which absolutely are
unknown to me. For instance, as the promotion of the fortune of
children ( = a) is to the love of parents ( = b), so the welfare of the
human species ( = c) is to that unknown [quality] in God ( = x), which
we call love ; not as if it had the least similarity to any human
inclination, but because we can suppose its relation to the world to be
similar to that which things of the world bear one another. But the
concept of relation in this case is a mere category, viz. the concept of
cause, which has nothing to do with sensibility.

164-165] THE BOUNDS OF PURE REASON 127

can prevent our predicating of this Being a causality
through Reason with regard to the world, and thus
passing to theism, without being forced to attribute to
Him in Himself this Reason, as a property inhering in Him.
For as to the former, the only possible way of prosecuting
the use of reason in the world of sense (as regards all
possible experience, in complete harmony with itself,)
to the highest point, is to assume a Supreme Reason
as a cause of all the connexions in the world : such a
principle must be thoroughly advantageous to our Reason,
but can hurt it nowhere in its natural use. Secondly,
Reason is thereby not transferred as a property to the First
Being in Himself, but to His relation to the world of sense,
and so anthropomorphism is entirely avoided. For nothing
is considered here but the Cause of the rational form
[ Vernunftfonn\ which is perceived everywhere in the world,
and reason is attributed to the Supreme Being, so far as it
contains the ground of this rational form of the world, but
analogically only, that is, so far as this expression shows
merely the relation, which the Supreme Cause unknown to
us has to the world, in order to determine everything in it
conformably to reason in the highest degree. We are
thereby kept from using this [human] attri-[i65] bute,
Reason, for the purpose of conceiving God by means of it,
instead of conceiving the world in the manner which is ne
cessary, in order to have the greatest possible systematic use
of reason with regard to it}- We thereby acknowledge, that
the Supreme Being is quite inscrutable and even incogit-
able in any determinate way as to what He is per se. We
are thereby kept, on the one hand, from making a tran
scendent use of the concepts which we have of reason as an

1 This whole section is very inaccurately and confusedly written.
The italics in this sentence are mine. M.

128 PROLEGOMENA TO METAPHYSIC [165-166

efficient cause (by means of the will), in order to determine the
Divine Nature by properties, which are only borrowed from
human nature, and from losing ourselves in gross and
extravagant notions ; and on the other hand [we are kept]
from deluging the contemplation of the world with hyper-
physical modes of explanation according to our notions of
human reason, which we transfer to God, and so losing for
this contemplation its proper destination, according to which
it should be a rational study of mere nature, and not a pre
sumptuous derivation of its phenomena from a Supreme
Reason. The expression suited to our feeble notions is,
that we conceive the world as if it came, as to its existence
and internal determination, from a Supreme Reason, by
which notion we both cognise the constitution, which belongs
to it (the world) [166] itself, yet without pretending to de
termine the nature of its cause per se, and on the other
hand we place the ground of this constitution (of the
rational form in the world) in the relation of the Supreme
Cause to the world, without finding the world sufficient by
itself for that purpose.1

And thus the difficulties, which seem to oppose theism,
disappear by combining with Hume's principle — ' not to
carry the use of reason dogmatically beyond the field of all
possible experience ' — this other principle, which he quite
overlooked : ' not to consider the field of experience as one
which bounds itself in the eye of our reason.' The Kritik

1 I may say, that the causality of the Supreme Cause holds the same
place with regard to the world that human reason does with regard to
its works of art. Here the nature of the Supreme Cause itself remains
unknown to me : I only compare its effects (the order of the world)
which I know, and their conformity to reason, to the effects of human
reason which I also know ; and hence I term the former reason, with
out attributing to it on that account what I understand in man by this
term, or attaching to it anything else known to me, as its property.

I66-I68] THE BOUNDS OF PURE REASON 129

of pure Reason here points out the true mean between
dogmatism, which Hume combats, and scepticism, which
he would substitute for it — a mean which is not like other
means that we find advisable to determine for ourselves as
it were mechanically (by adopting something from one side
and something from the other), and by which nobody is
taught a [167] better way, but such a one as can be ac
curately determined on principles.

§ 59. At the beginning of this observation I made use
of the metaphor of a boundary, in order to establish the
limits of reason in regard to its suitable use. The world of
sense contains merely phenomena, which are not things in
themselves, which (noumena) therefore the understanding
must assume. In our Reason both are comprised, and the
question is, How does reason proceed to bound the under
standing as regards both these fields ? Experience, which
contains all that belongs to the sensuous world, does not
bound itself ; it only attains from every conditioned to some
other equally conditioned object. Its boundary must lie
quite without it, and this field is that of the pure beings of
the understanding. But this field, so far as the determina
tion of the nature of these beings is concerned, is an empty
space for us, and if dogmatically-determined concepts alone
are in question, we cannot pass out of the field of possible
experience. But as a boundary itself is something positive,
which belongs as well to that which lies within, as to the
space that lies without the given complex, it is still an
actual positive cognition, which reason only acquires by
enlarging itself to this boundary, yet without attempting to
pass it ; because it there finds itself in presence of an empty
space, in which it can conceive forms of things, but not
things themselves. [168] But the bounding of the field of
the understanding by something, which is otherwise un-

II K

130 PROLEGOMENA TO METAPHYSIC [168-169

known to it, is still a cognition which remains to reason
even at this standpoint, and by which it is neither shut up
within the sensible, nor does it stray without it, but confines
itself, as befits the knowledge of a boundary, to the relation
between that which lies without it, and that which is con
tained within it.

Natural theology is a concept of that sort at the
boundary of human reason, because we are obliged to look
beyond this boundary to the Idea of Supreme Being (and,
in morals to that of an intelligible world also). [We do
this] not in order to determine anything relatively to this
mere being of the understanding, and consequently beyond
the world of sense, but in order to guide the use of reason
within it according to principles of the greatest possible
(theoretical as well as practical) unity. For this purpose
we make use of the reference of the world of sense to a
self- sufficient reason, as the cause of all its connexions.
But [we do this] not in order merely to invent a being for
ourselves, but, as beyond the sensible world there must be
something thought only by the pure understanding, to
determine that something in this particular way, though only
of course according to analogy.

And thus there remains our original proposition, which
is the result of the whole Kritik : 'that reason [169] by all
its a priori principles never teaches us anything more than
objects of possible experience, and even of these nothing
more than can be cognised in experience.' But this
limitation does not prevent the reason leading us to the
objective boundary of experience, viz. to the reference to
something which is not itself an object of experience, but is
the ground of all experience. Reason does not however
teach us anything concerning the thing in itself: it only
instructs us as regards its own complete and noblest use in

169-170] THE BOUNDS OF PURE REASON 131

the field of possible experience. But this is all that can be
reasonably desired in the present case, and with which we
have cause to be satisfied.

§ 60. Thus we have fully exhibited Metaphysic as it is
actually given in the natural predisposition of human reason,
and in that which constitutes the essential end of its
pursuit, [and have explained it] according to its subjective
possibility. Yet we have found, that this merely natural
use of such a predisposition of our reason, if no discipline
arising only from a scientific Kritik bridles and sets limits
to it, involves us in transcendent, either apparently or really
conflicting, dialectical syllogisms. We here also found this
fallacious Metaphysic not only unnecessary as regards the
promotion of our knowledge of nature, but even disadvan
tageous to it. There still therefore remains a problem
worthy of solution, to find out the natural ends intended
by [170] this disposition to transcendent concepts in our
reason, because everything that lies in nature must be
originally intended for some useful purpose.

Such an inquiry is here out of place ; and I acknow
ledge, that what I can say about it is conjecture only,
like every speculation about the first ends of nature. It
may be allowed me in this case only, as the question does
not concern the objective validity of metaphysical judg
ments, but our natural predisposition to them, and therefore
belongs to anthropology, outside the system of Metaphysic.

When I [consider1] all the transcendental Ideas, the
complex of which constitutes the peculiar problem of
natural pure reason, and compels it to quit the mere
contemplation of nature, to transcend all possible experience,
and in this endeavour to produce the thing (be it knowledge
or nonsense) called Metaphysic, I think I perceive that the
1 There is no verb in the original, as also below. M.

132 PROLEGOMENA TO METAPHYSIC [170-171

aim of this natural tendency is, to free our notions from
the fetters of experience and from the limits of the mere
contemplation of nature so far as at least to open to us a
field, which contains mere objects for the pure under
standing, which no sensibility can reach. [We do this]
not indeed with the view of speculatively occupying our
selves with them (because we can find no ground to stand
on), but, in order that practical principles [may be secured],
which, with- [171] out finding some such scope for their
necessary expectation and hope, could not expand to the
universality, which reason unavoidably requires from the
moral point of view.

So I find that the Psychological Idea (however little it may
reveal to me the nature of the human soul, which is pure
and raised above all concepts of experience), yet shows the
insufficiency of these concepts plainly enough, and thereby
deters me from materialism, as a notion unfit for any
explanation of nature, and besides confining reason [unduly]
in the practical direction. The Cosmological Ideas, by the
obvious insufficiency' of all possible cognition of nature to
satisfy reason in its lawful inquiry, serve in the same
manner to keep us from naturalism, which asserts nature
to be sufficient for itself. Finally, all natural necessity in
the sensible world is conditional, as it always presupposes
the dependence of things upon others, and unconditional
necessity must be sought only in the unity of a cause
distinguished from the world of sense. But as the causality
of this cause, in its turn, were it merely nature, could never
render the existence of the contingent (as its consequent)
comprehensible, Reason frees itself by means of the Theo
logical Idea from fatalism (both as a blind natural necessity
in the coherence of nature itself, without a first principle,
as well as a blind causality of this principle itself), and

171-173] THE BOUNDS OF PURE REASON 133

leads to the concept of a cause possessing freedom, or of a
[172] Supreme Intelligence. Thus the transcendental
Ideas serve, if not to instruct us positively, at least to
destroy the rash assertions of Materialism, of Naturalism,
and of Fatalism, and thus to afford scope for the moral
Ideas beyond the field of speculation. These considera
tions, I should think, explain in some measure the natural
predisposition of which I spoke.

The practical value, which a merely speculative science
may have, lies without the [strict] bounds of this science,
and can therefore be considered as a scholion merely, and
like all scholia does not form part of the science itself.
This application however surely lies within the bounds of
philosophy, especially 'of philosophy drawn from the pure
sources of reason, where its speculative use in Metaphysic
must necessarily be at unity with its practical use in morals.
Hence the unavoidable dialectic of pure reason, considered
in Metaphysic as a natural tendency, deserves to be ex
plained not as an illusion merely, which is to be removed,
but also, if possible, as a natural provision as regards its end,
though this duty, a work of supererogation, cannot justly
be assigned to Metaphysic proper.

The solutions of the questions which occupy from page
410 of the Kritik to page 432, should be considered a
second scholion, which however has a greater affinity with
the content of Metaphysic. For there certain rational
principles are expounded, [173] which determine a priori
the order of nature or rather of the understanding, which
seeks nature's laws through experience. They seem to be
constitutive and legislative with regard to experience, though
they spring from mere Reason, which cannot be considered,
like the understanding, as a principle of possible experience.
Now does this harmony rest upon the fact, that just as

134 PROLEGOMENA TO METArHYSIC [i73'i74

nature does not inhere in phenomena or in their source (the
sensibility) per se, but only in so far as the latter is in
relation to the understanding, so thorough unity in applying
the understanding to obtain a collective possible experience
(in a system) can only belong to the understanding when
in relation to Reason? and is experience in this way
mediately subordinate to the legislation of Reason ? The
answer may be discussed by those who desire to trace the
nature of reason even beyond its use in Metaphysic, into
the general principles of systematising a history of nature ;
I have represented this problem as important, but not
attempted its solution, in the book itself.1

[174] And thus I conclude the analytical solution of
the problem I had proposed : How is metaphysic in general
possible ? by ascending from the facts, where the use of the
science is actually given, at least in its consequences, to the
grounds of its possibility.

1 It was my constant design through the Kritik to neglect nothing,
were it ever so dark, that could complete the inquiry into the nature of
pure reason. Everybody may afterwards carry his researches as far as
he pleases, when he has been merely shown what yet remains to be
done, a duty reasonably to be expected from those who have made it
their business to survey the whole of this field, in order to consign it to
others for future allotment and cultivation. And to this branch both
the scholia belong, which will hardly recommend themselves by their
dryness to amateurs, and hence are added for competent judges only.

[i7S] SOLUTION OF THE GENERAL QUESTION
OF THE PROLEGOMENA

How is Metaphysic possible as a Science ?

METAPHYSIC, as a natural tendency of reason, is actual, but
when isolated (as the analytical solution of the third principal
question showed) dialectical and illusory. If we think of
taking principles from it, and following in their use the
natural, but on that account not less false, illusion, we can
therefore never produce science, but only a vain dialectical
art, in which one school may overcome another, but none
can ever acquire a just and lasting approbation.

In order that as a science it may claim not mere
fallacious plausibility, but insight and conviction, a Kritik
of the Reason must itself exhibit the whole stock of a priori
concepts, their division according to their various sources
(Sensibility, Understanding, and Reason), together with a
complete table of them, and the analysis of all these
concepts, with all their consequences.

It must also exhibit, especially by means of the deduc
tion of these concepts, the possibility of [176] synthetical
cognition a priori, the principles of its use, and finally
its bounds, all in a complete system.1 Kritik therefore,

1 I may note, as a specimen of Kant's style, that in the original there
are seventy-two words in this paragraph between the subject and the
verb. M.

136 PROLEGOMENA TO METAPHYSIC [176-177

and Kritik alone, contains in itself the whole well proved
and tested plan, and even all the means required to ac
complish Metaphysic as a science; by other ways and
means it is impossible. The question here therefore is not
so much how this performance is possible, as how to set it
going, and induce men of clear heads to quit their hitherto
perverted and fruitless cultivation for one that will not
deceive, and how such a union for the common end may
best be directed.

This much is certain, that whoever has once tasted
Kritik, will be ever after disgusted with all dogmatical slops,
which he formerly put up with, because his reason must
have something, and could find nothing better for its
support. Kritik stands in the same relation to the common
Metaphysic of the schools, as chemistry does to alchemy, or
as astronomy to prognosticating astrology. I pledge myself,
that nobody who has read through and through, and grasped
the principles of, the Kritik, even in these Prolegomena
only, will ever return to that old and sophistical mock
science; but will [177] rather with a certain delight look
forward to Metaphysic, which is now indeed in his power,
and requires no more preparatory discoveries, and which
can at last afford permanent satisfaction to reason. For
here is an advantage upon which, of all possible sciences,
Metaphysic alone can with certainty reckon : that it can be
brought to such completion and fixity as to be incapable of
further change, or of any augmentation by new discoveries ;
because here reason has the sources of its knowledge not in
objects and their intuition (by which too it cannot be further
informed), but in itself. When therefore it has exhibited
the fundamental laws of its faculty completely, and so
determinately as to avoid all misunderstanding, there
remains nothing for pure reason to cognise a priori, nay,

177-178] HOW IS METAPHYSIC POSSIBLE ? 137

even for it to inquire into on [reasonable] grounds. The
sure prospect of knowledge so determinate and so self-
contained1 has a peculiar charm, even though we should
set aside all its advantages, of which I shall hereafter speak.

All false art, all vain wisdom lasts its time, but finally
destroys itself, and its highest culture is also the epoch of
its decay. That this time is come for Metaphysic appears
from the state into which it has fallen among all learned
nations, [178] despite of all the zeal with which other
sciences of every kind are prosecuted. The old arrange
ment of our university studies still preserves its shadow ; a
single Academy of Sciences tempts men now and then, by
offering prizes, to write essays on it, but it is no longer
numbered among thorough sciences ; and let any one judge
for himself how a man of parts, if he were called a great
metaphysician, would receive the compliment, which may
be well-meant, but is scarce envied by anybody.

Yet, though the period of the downfall of all dogmatical
metaphysic has undoubtedly arrived, we are yet far from
being able to say, that the period of its regeneration is come
by means of a thorough and complete Kritik of the Reason.
All transitions from a tendency to its contrary pass through
the stage of indifference, and this moment is the most
dangerous for the author, but, in my opinion, the most
favourable for the science. For, when party spirit has died
out by a total dissolution of former connexions, minds are
in the best state to receive, but gradually, proposals for a
combination according to a new plan.

When I say, that I hope these Prolegomena will excite
investigation in the field of Kritik, and afford a new and
promising object to sustain the general spirit of philosophy,

1 This word does not adequately render the untranslatable original
Geschlossenes. M.

138 PROLEGOMENA TO METAPHYSIC [178-180

which seems on its speculative side to want sustenance, I
can imagine [179] beforehand, that every one, whom the
thorny paths of my Kritik have tired and put out of
humour, will ask me, upon what I found this hope ? My
answer is, upon the irresistible law of necessity.

That the human mind will ever give up metaphysical
researches entirely is as little to be expected as that we
should prefer to give up breathing altogether, to avoid inhaling
impure air. There will therefore always be Metaphysic in
the world ; nay every one, especially every man of reflection,
will have it, and for want of a recognised standard, will
shape it for himself after his own pattern. What has
hitherto been called Metaphysic, cannot satisfy any accu
rate mind, but to forego it entirely is impossible \ therefore
a Kritik of Pure Reason itself must now be attempted or, if
one exists, investigated, and brought to the full test, because
there is no other means of supplying this pressing want,
which is something more than mere thirst for knowledge.

Ever since I have come to know Kritik, when I have
finished reading a book of metaphysical contents, which, by
the preciseness of its notions, by variety, order, and an
easy style, was not only entertaining but improving, I cannot
refrain from asking, Has this author indeed advanced Meta
physic a single step ? The learned men, whose works have
been useful to me in other respects and always contributed
to the culture of my mental pow- [180] ers, will, I hope,
forgive me for saying, that I have never been able to find either
their essays or my own less important ones (though self-love
may recommend them to me) to have advanced the science
in the least. And here is the very obvious reason : that
the science did not then exist, and cannot be gathered
piecemeal, but its germ must be fully preformed in the Kritik.
But in order to prevent all misconception, we must remember

180-181] HOW IS METAPHYSIC POSSIBLE? 139

what has been already said, that by the analytical treatment
of our concepts the understanding gains indeed a great deal,
but the science (of metaphysic) is not the least advanced,
because these dissections of concepts are nothing but the
materials from which the science still remains to be built.
Let the concepts of substance and of accident be ever so
well dissected and determined, all this is very well as a
preparation for some future use. But if we cannot prove,
that in all which exists the substance endures, and only the
accidents vary, science is not the least advanced by all
our analyses. Metaphysic has hitherto never been able to
prove a priori either this proposition, or that of Sufficient
Reason, still less any more complex one, such as belongs
to [rational] psychology or cosmology, or indeed any syn
thetical proposition. By all its analysis therefore nothing
is affected, nothing obtained or forwarded, and the science,
after all this bustle and noise, still remains as it was in the
[181] days of Aristotle, though far better preparations were
made for it than of old, if the clue to synthetical cognitions
had only been discovered.

If any one thinks himself insulted, he may easily refute
my charge by producing a single synthetical proposition
belonging to Metaphysic, which he proposes to prove
dogmatically a priori, for until he has performed this feat,
I shall not grant that he has actually advanced the science ;
even should that proposition be sufficiently confirmed by
common experience. No demand can be more moderate
or more equitable, and in the (infallibly certain) event of
its non- performance, no assertion more just, than that
hitherto Metaphysic has never existed as a science.

But there are two things which, in case the challenge be
accepted, I must deprecate : first, trifling about probability
and conjecture, which are suited as little to metaphysic, as

140 PROLEGOMENA TO METAPHYSIC [181-182

to geometry ; and secondly, the decision by means of the
wand of sound common sense, which every one does not
wave, but which accommodates itself to personal peculiarities.

For as to the former, nothing can be more absurd, than
in Metaphysic, a philosophy from pure reason, to think of
grounding our judgments upon probability and conjecture.
Everything that is to be cognised a priori, is thereby
announced as apodeictically certain, and must therefore be
proved [182] in this way. We might as well think of
grounding geometry or arithmetic upon conjectures ; for as
to the doctrine of chances in the latter, it does not contain
probable, but perfectly certain judgments concerning the
degree of the probability of certain cases, under given uni
form conditions, which, in the sum of all possible cases,
infallibly happen according to the rule, though it is not
sufficiently determined in respect to every single chance.
Conjectures (by means of induction and of analogy) can be
suffered in an empirical science of nature only, yet even
there the possibility at least of what we assume must be
quite certain.

The appeal to sound sense is even more absurd, when
concepts and principles are announced as valid, not in so
far as they hold with regard to experience, but even beyond
the conditions of experience. For what is sound sense
[Verstand] ? It is common sense, so far as it judges right.
But what is common sense ? It is the faculty of the know
ledge and use of rules in concreto, as distinguished from the
speculative understanding, which is a faculty of knowing rules
in abstracto. Common sense can hardly understand the
rule, ' that every event is determined by means of its cause,'
and can never comprehend it thus generally. It therefore
demands an example from experience, and when it hears
that this rule means nothing but what it always thought

182-184] HOW IS METAPHYSIC POSSIBLE ? 141

when a pane was [183] broken or a kitchen-utensil missing,
it then understands the principle and grants it. Common
sense therefore is only of use so far as it can see its rules
(though actually present in it a priori] confirmed by ex
perience ; consequently to comprehend them a priori, or
independently of experience, belongs to the speculative
understanding, and lies quite beyond the horizon of common
sense. But the province of Metaphysic is entirely confined
to the latter kind of knowledge, and it is certainly a bad
index of sound sense to appeal to the witness, which cannot
here form any opinion whatever, and on which men look
down with contempt until they are in difficulties, and can
find in their speculation neither counsel nor help.

It is a common subterfuge of those false friends of
common sense (who occasionally prize it highly, but usually
despise it) to say, that there must surely be at all events
some propositions, which are immediately certain, and of
which there is no occasion to give any proof, or even any
account at all, because we otherwise could never stop in
quiring into the grounds of our judgments.1 But if we ex
cept the principle of contradiction, which is not sufficient to
show the truth of synthetical judgments, they can never
adduce, in proof of this privilege, anything [184] else in
dubitable, which they can immediately ascribe to common
sense, except mathematical propositions, such as twice two
make four, between two points there is but one straight line,
etc. But these are judgments immensely distinct from those
of Metaphysic. For in Mathematic I myself can by thinking
make (construct) whatever I represent to myself as possible
by a concept : I add to the first two the other two, one by
one, and myself make the number four, or I draw in thought

1 These remarks are probably written with the Scottish School in
view. M.

I42 PROLEGOMENA TO METAPHYSIC [184-185

from one point to another all manner of lines, and can draw
one only, which is like itself in all its parts (equal as well as
unequal). But I cannot, by all my power of thinking,
extract from the concept of a thing the concept of something
else, whose existence is necessarily connected with the former,
but must call in experience. And though my understanding
furnishes me a priori (yet only in -reference to possible ex
perience) with the concept of such a connexion (of causation),
I cannot exhibit it, like the concepts of mathematic, by in
tuition, a priori^ and so show its possibility a priori. So
this concept, together with the principles of its application,
always requires, if it shall hold a priori — as is requisite in
Metaphysic — a justification and deduction of its possibility,
because we cannot otherwise know how far it holds good,
and whether it can be used in experience only or beyond it
also. In Metaphysic, then, as a speculative science of pure
reason, we [185] can never appeal to common sense, but
may only do so when we are forced to quit it, and to give
up all pure speculative cognition (which must always be
science), and consequently [to give up] metaphysic itself,
and its instruction. [This may happen] on certain occasions,
when a reasonable faith only is found possible for us, and
sufficient to our wants (perhaps even more salutary than
science itself). For in this case the attitude of the question
is quite altered. Metaphysic must be science not only as a
whole, but in all its parts, otherwise it is nothing ; because,
as a speculation of pure reason, it has a footing nowhere else
than on general views. Beyond it, however, probability and
sound sense may be used with advantage and justly, but on
quite special principles, of which the importance always de
pends on the reference to practice.

This is what I hold myself justified in requiring for the
possibility of Metaphysic as a science.

[i86] APPENDIX

On what can be done to make Metapkysic actual as a Science

As no means hitherto used have attained this end, which
without a preceding Kritik of pure reason will never be
attained, it is fair to expect that the essay, which is now be
fore the public, should be submitted to an accurate and
careful scrutiny, except it be thought more advisable to give
up all pretensions to Metaphysic, in which case, if men but
adhere to their purpose, nothing can be said against it. If
we take the course of things as it is, not as it ought to be,
there are two sorts of judgments, one a judgment which pre
cedes investigation — in our case one in which the reader from
his own Metaphysic pronounces judgment on the Kritik of
Pure Reason (which was intended to discuss the very
possibility of Metaphysic). The other is a judgment sub
sequent to investigation, in which the reader is enabled to
waive for awhile the consequences of the critical researches
that may be repugnant to his formerly adopted Metaphysic,
and first examines the grounds whence those consequences
are derived. If what common Metaphysic propounds were
[187] demonstrably certain (like geometry, for instance),
the former way of judging would hold good ; for if the con
sequences of certain principles are repugnant to established
truths, these principles are false, and without further inquiry

144 PROLEGOMENA TO METAPHYSIC [187

to be repudiated. But if Metaphysic does not possess a
stock of indisputably certain (synthetical) propositions, and
should it even be the case that there are a number of them,
which, though among the most specious, are by their con
sequences in mutual collision, and if no sure criterion of the
truth of peculiarly metaphysical (synthetical) propositions is
to be met with in it, then the former way of judging cannot
obtain, but the investigation of the principles of the Kritik
must precede all judgment as to its value.

SPECIMEN OF A JUDGMENT ON THE KRITIK
PRIOR TO ITS EXAMINATION

Such may be found in the Gbttingen gelehrte Anz. (iQth Jan. 1782).

WHEN an author who understands his work, and has
taken care to think it out independently, falls into the
hands of a reviewer acute enough to perceive the points
of real moment in determining the merit or demerit of the
book, who attends not to the words but to the matter, and
does not merely weigh the principles from which the author
started — in such case the latter may dislike his verdict,
but the public, who only gains by it, need not care : and
even the author may be content to take the opportunity of
reconsidering the positions criticised in good time by a
good authority, and thus, should the objections be well
grounded, of removing any rock of offence which might
damage the work.

This is not my present position. My critic does not
seem to have an inkling of what my inquiry (successful or
not) aimed at attaining. It may be want of patience to
toil through a voluminous book, or annoyance at a proposed
reform in a science concerning which he had long since
satisfied himself, or (what I do not willingly surmise) a
narrow view which cannot rise above the ordinary meta-
physic of the schools. Whatever the cause, he goes

II L

146 PROLEGOMENA TO METAPHYSIC

through a long row of propositions, which nobody -would
understand without the premises leading up to them,
dispenses here and there his censure, which is as incompre
hensible as the statements censured, and so neither profits
the public by information, nor damages me the least in the
minds of experts. I should therefore have passed it by
in silence, except that it gives me the opportunity of ex
planations which may save the readers of my Prolegomena
from some possible mistakes.

In order to take up a position from which he could give
an unfavourable view of the whole book, without con
descending to any particular inquiry, the reviewer begins
and ends with saying, " this work is a system of transcend
ent (or as he translates it, of higher)1 idealism. A glance
at this statement told me what I might expect — something
like as if a man who had never heard of geometry had
suddenly found a Euclid, and being asked to review it,
were to turn over the leaves and find many figures, and then
say : " The book is a systematic lesson-book in drawing ;
but the author uses a peculiar language to give dark and
obscure precepts, which after all can do no more than any
one can attain with a good eye, etc."

But let us see what sort of idealism runs through my

1 By no means higher. High towers, and their human rivals in
metaphysic, both with so much wind about them, are not in my line.
My place is the fruitful low ground [bathos] of experience ; and 'the
word transcendental, whose repeated explanation in my book he has
never even grasped — so hurriedly did he read me — does not mean any
thing transcending all experience, but its a priori condition, with no
other purpose than to make empirical cognition merely possible. When
these concepts transcend experience, their employment becomes tran
scendent, which is distinguished from their immanent use confined to
experience. All this I had carefully guarded against ; but the reviewer
found it his advantage to misunderstand me.

SUPPLEMENT

whole work, though it is far from being the soul of my
system.

The position of all genuine idealists from the Eleatics
to Berkeley is this : All cognition through the senses and
experience is nothing but mere illusion, and only in the
ideas of the pure Understanding and the Reason is there
truth. The fundamental principle ruling all my idealism,
on the contrary, is this: All cognition of things from
mere pure Understanding and Reason is nothing but mere
illusion and only in experience is there truth.

But this is the very opposite of that other proper
idealism. How did I come to use this term for a directly
opposite purpose, and how did the reviewer come to see
it everywhere ?

The solution of this difficulty depends upon something
easy to take out of the connected work, if you choose to do
it. Space and time, with all that they contain, are not
things or their properties per se, but belong to the pheno
mena of things. So far I agree with every idealist. But
these, especially Berkeley, regarded space as a mere
empirical representation, which along with all its determina
tions is known, like what appears in it, only through
experience or perception. I was the first to show that
space (and time, which Berkeley overlooked) with all its
determinations is known by us a priori, because it and
time are in us as pure forms of sensibility before all
perception or experience, and make all intuition and con
sequently all phenomena possible. Hence it follows that
as truth rests on universal and necessary laws as its criteria,
experience can have in Berkeley's system no criteria of
truth, because there is nothing a priori at the basis of its
phenomena; and further it follows that all experience is
mere illusion, whereas with me space and time (in con-

148 PROLEGOMENA TO METAPHYSIC

nection with the Categories) prescribe a priori the law
of all possible experience, and this law gives us the sure
criterion for distinguishing truth from illusion.1 My so-
called (critical) idealism is thus quite peculiar, in that it
overthrows ordinary idealism, and that through it all a
priori cognition, even that of geometry, now attains objective
reality, a thing which even the keenest realist could not
assert till I had proved the ideality of space and time. I
wish I could call this attitude of mine by some other name,
to avoid all such misapprehensions, but a complete change
seems to me impracticable. I may therefore in future be
allowed to call it, as above explained, formal, or rather
critical, idealism, to distinguish it from the dogmatic of
Berkeley, and the sceptical of Descartes.

I find nothing further of note in this estimate of my
book.2 The critic deals throughout in broad generalities —
a wise course, because the writer does not betray the
amount of his own knowledge or ignorance ; a single
criticism in detail, affecting, as it ought, the main questions
of the book, would have exposed perhaps my error,
perhaps also the amount of insight the reviewer possessed
into questions of this kind. It was no bad device, for the
purpose of deterring at once readers accustomed to rely on
reviews for their opinion of books, to enumerate a number
of statements, which must necessarily have seemed absurd

1 Idealism proper has always, and necessarily, a mystical tendency,
but mine only aims at comprehending the possibility of knowing the
things of experience a priori — a problem never solved, nay, never
even proposed. This disposes of mystical idealism, which (as Plato
shows) infers from our a priori cognitions (even in geometry)
another (viz. intellectual) intuition, differing from that of the senses,
because no one dreamt that the senses could have any a priori
intuition.

' Not the judgment of the book in question,' as Mr. Bax translates,
evidently supposing it to be some work of Garve. M.

SUPPLEMENT 149

when torn from their connection with proofs and explana
tions, and which, moreover, conflict violently with current
metaphysic. So the reader's patience is disgusted, and
then, after I am taught the profound statement, that per
sistent illusion is truth — then comes the blunt patronising
conclusion : Why this attack on the received use of words ;
wherefore this idealistic distinction ? This judgment,
which began with making metaphysical heresies the main
point of my book, ends by reducing it to mere innovations
of language, and shows clearly that my would-be judge
knows nothing about the subject, and even misunderstands
his own arguments.1

The reviewer talks like a man possessed of important
news, which he keeps concealed from the public, though I
know of nothing which has lately appeared in metaphysics
to warrant such an attitude. It is very wrong of him to
withhold his discoveries for ... the world is tired of
metaphysical assertions ; what we want is a proof of the
possibility of this science, and safe criteria to distinguish
the dialectical illusion of the pure reason from truth. I
suspect that this requirement has never even come into his
head, and . . . support my suspicions by the fact that he
is absolutely silent concerning the possibility of synthetic
a priori knowledge, which is the special problem in the
way of metaphysic, and to which my Kritik and Prolegomena

1 The reviewer often fights with his own shadow. When I oppose
the truth of experience to dreaming, he never suspects that I am only
concerned with the somni-um objective sumtum of Wolffs philosophy,
which is merely formal, and does not regard the distinction of dreaming
and waking, which indeed has no place in any transcendental philosophy.
Again he calls my Deduction of the Categories and Table of the
Principles of the Understanding 'current principles of Logic and Ontology
idealistically expressed.' The reader need only consult these Pro
legomena^ to persuade himself, that such a criticism was the most
miserable and even historically false which a man could make.

1 5o PROLEGOMENA TO METAPHYSIC

were mainly directed. The idealism at which he caught,
and to which he stuck, was only embraced by me as the
one means of solving that problem (though it may be con
firmed from other grounds), and he should have shown,
either that the problem does not possess the importance I
attached to it, both in Kritik and Prolegomena, or that it
cannot be solved by my view of phenomena, or else be
solved better in some other way. . . . Other sciences
have their touchstone.1 But to judge the thing called
metaphysic, we must first discover that touchstone, which
I have attempted, as well as to apply its use. ... To
bring my defence to a point, I here make an offer, like
those often made by the mathematicians, to prove by com
petition the superiority of their respective methods. I
challenge my opponent to prove, of course a priori, a
single one of the propositions asserted by him to be really
metaphysical, i.e. synthetical a priori, such as the principle
of the permanence of substance, or the necessary deter
mination of events by their causes. If he fails in doing
this, he must admit that as metaphysic is nothing at all
without the demonstrated certainty of such propositions,
the possibility or impossibility of the science is the first
task of a Kritik of pure reason ; either, then, he must confess
that my principles are sound, or he must refute them. . . .
So sure am I of his failure in any such attempt, that I will
even give him the advantage of taking the onus probandi
on myself.

Here is my challenge. He finds in these Prolegomena
and Kritik eight pieces of contradictory propositions (the
Theses and Antitheses of the four Antinomies), each of

1 From this on I have only given the philosophical points in
Kant's argument, the personal allusions are now devoid of interest
to the philosophical reader. M.

SUPPLEMENT

which belongs necessarily to metaphysic, which must
either accept or refute it (though there is probably not a
single one of them which has not in its turn been assumed
by some philosopher). He is at liberty to accept any one
of these eight, and adopt it with the proof, which I give
him into the bargain, and then let him attack my proof of
the contrary proposition. If I can protect this latter, and
show on principles indispensable to every dogmatical
metaphysic that the opposite of his position can be just as
clearly maintained, then there must be a radical error in
metaphysic not to be explained or removed without going
back to the birthplace of metaphysic in the pure reason ;
so that either my Kritik must be adopted or a better
supplied in its place.

If I am not able to maintain my proof, then my opponent
has made good at least one synthetical a priori pro
position on dogmatical grounds ; my attack on popular
metaphysic was unwarranted, and I bow to his censure.

APPENDICES

CONTAINING

TRANSLATIONS OF THE PRINCIPAL PASSAGES IN THE KRIT1K

OF THE PURE REASON ALTERED IN THE SECOND (AND

FOLLOWING) EDITIONS, AND OF PART OF

THE CRITICAL SOLUTION OF THE

THIRD ANTINOMY

A. ON THE DEDUCTION OF THE CATEGORIES

B. ON THE DISTINCTION BETWEEN NOUMENA AND PHENO

MENA

C. ON THE PARALOGISMS OF RATIONAL PSYCHOLOGY

D. ON THE INTELLIGIBLE AND THE EMPIRICAL CHARACTER

APPENDIX A

DEDUCTION OF THE PURE CONCEPTS OF
THE UNDERSTANDING

§ 2. Of the a priori Grounds of the Possibility of Experience

THAT a concept should be generated completely a priori,
and have relation to an object, without itself belonging to
the [general] notion of possible experience, or being made
up of the elements of possible experience 1 — this is perfectly
self- contradictory and impossible. For such a concept
would have no content, because no intuition would cor
respond to it ; since intuitions in genera], by which objects
are capable of being given to us, make up the field, or
total object, of possible experience. A concept a priori,
which did not refer to such intuitions, would be only the
logical form for a concept, but not the very concept itself,
through which something is thought.

If there be then pure concepts a priori, these indeed
can of course contain nothing empirical ; they must, never
theless, be merely a priori conditions of possible [192] ex
perience, as upon this alone can their objective reality rest.

1 By possible experience Kant means that which can possibly become
experience. M.

iS6 APPENDIX A [192-193

If we wish, then, to know how pure concepts of the
understanding are possible, we must inquire what are the
a priori conditions on which the possibility of experience
depends, and which form its foundation, when we abstract
from all that is empirical in phenomena. A concept which
expresses this formal and objective condition of experience
universally and adequately might be denominated a pure
concept of the understanding. Having once obtained pure
concepts of the understanding, I can, if I like, also
excogitate objects, perhaps impossible, perhaps possible /^
se, but given in no experience ; since I may omit in the
connexion of these concepts something which still neces
sarily belongs to the conditions of possible experience (e.g.
the notion of a spirit) ; or else I may extend pure concepts
of the understanding further than experience can reach (e.g.
the notion of the Deity). But the elements of all a priori
cognitions, even those of capricious and absurd chimeras,
cannot indeed be borrowed from experience (or they would
not be a priori cognitions), but must in every case contain
the pure a priori conditions of possible experience, and of
an object thereof; otherwise we should not only be thinking
nothing by means of such chimeras, but they themselves,
having no starting-point, could not even originate in
thought.

Now these concepts, which contain a priori the pure
thinking in each individual experience, we find in the
Categories ; and it will be a sufficient deduction of them,
and a justification of their objective validity, if we prove
that through them alone can an object be thought. But,
as in such a thought there is more than the mere faculty
[193] of thinking — that is, the understanding — concerned;
and as this faculty, considered as a cognitive faculty, which
must relate to objects, will also require some explanation,

193-194] DEDUCTION OF THE CATEGORIES

157

with regard to the possibility of such relation ; — we must,
accordingly, first discuss the subjective sources1 which
constitute the a priori foundation of the possibility of
experience, not according to their empirical, but according
to their transcendental, nature.

If each individual representation were quite estranged
from the rest, so as to be as it were isolated and separated
from them, such a thing as knowledge never could come
into existence ; for knowledge means a totality of compared 1
and connected representations. If then I add to sense, (
because it contains multiplicity in its intuition, a synopsis,
to this synopsis must correspond in every case a synthesis ;
and it is only when combined with spontaneity that re
ceptivity can make cognitions possible. This spontaneity,
then, is the foundation of a threefold synthesis, which
necessarily occurs in all knowledge : first, the apprehension
of representations, as modifications of the mind in intuition ;
secondly, the reproduction of them in the imagination ; and,
thirdly, their recognition in the concept. These point to
three subjective sources of cognition which render possible
the understanding itself, and through it experience also, as
an empirical product of the understanding.

[194] PREFATORY REMARK

The deduction of the Categories is involved in such
difficulties, and compels us to penetrate so deeply into the
original causes and conditions of the possibility of our
knowledge in general, that in order to avoid the diffuseness
of a complete theory, and at the same time to omit nothing

1 This is the aspect omitted in the Second Edition, and alluded to
in the first Preface. Cf. vol. i. p. 5. M.

158 APPENDIX A [i94'i95

in so necessary an investigation, I have thought it better, in
the four following paragraphs, rather to prepare than in
struct the reader, and not to lay before him the systematic
discussion of these elements of the understanding till the
succeeding third section. I hope the reader will not permit
the obscurity he at first meets to deter him, as such obscurity
is unavoidable on entering upon a wholly untrodden path,
but will, I hope, be perfectly removed in the section to
which I have referred.

i. Of the Synthesis of Apprehension in Intuition. — From
whatsoever source our representations arise — whether
through the influence of external things, or from internal
causes l — whether they originate a priori, or empirically,
they must nevertheless belong as phenomena (being modifica
tions of our minds) to the internal sense ; and, as such, all
our cognitions must ultimately be subject to the formal
condition of our internal sense — Time — as being that in
which they are all ordered, connected, and brought into
relation. This general remark must be above all things
kept carefully in view throughout the following discussion.

Every intuition contains in itself a multiplicity, which
nevertheless would not be represented as such, if the [195]
mind did not distinguish time in the sequence of im
pressions one upon another ; for, so far as it is contained
in a single instant, no representation could ever be anything
but an absolute unity. In order, then, to make out of this
manifold a unity of intuition (as, for example, in the
representation of space),2 it is in the first instance necessary

1 This looks very like a suggestion of Realism in the First Edi
tion. M

2 The reader should here notice the element omitted (for the sake of
simplicity) in Kant's Aesthetic, and to which he afterwards refers,
Kritik, p. 98, note. M.

195-196] DEDUCTION OF THE CATEGORIES 159

to run through the multiplicity, and then grasp it together
— an action which I call synthesis of apprehension, as being
directed immediately towards intuition, which indeed pre
sents to us multiplicity, but which without a simultaneous
synthesis cannot produce it as such, and also as contained
in one representation.

Now this synthesis of apprehension must also be carried
out a priori^ that is to say, in the case of representations
which are not empirical. For without it we could not have
representations either of space or time a priori, as these
can only be generated by means of the synthesis of the
manifold, which [manifold] the sensibility offers in its
original receptivity. We have then a pure synthesis of
apprehension.

2. Of the Synthesis of Reproduction in the Imagination. —
It is indeed only an empirical law, according to which
representations which have often accompanied or followed
one another at length become associated, and so form a
connexion, according to which, even in the absence of the
object, one of these representations produces a transition of
the mind to another, by a fixed rule. But this law of
reproduction presupposes that phenomena themselves are
actually subject to such a rule, [196] and that in the
multiplicity of their representations there is a concomitance
or sequence, according to a fixed rule; for otherwise our
empirical imagination would never find anything to do
suited to its nature, and would consequently remain hidden
within the depths of the mind as a torpid faculty, not
even known to ourselves. Supposing vermilion were at one
time red, at another black — at one time heavy, at another
light ; were a man changed first into one, then into another
animal — were our fields covered on the longest day, at one
time with corn, at another with ice and snow — then my

i6o APPENDIX A [196-197

empirical faculty of imagination would never have had even
the opportunity of thinking of the heavy vermilion, when
red colour was presented to it ; or again, were a certain
word applied first to one thing, then to another, or the
same thing called by different names, without the control
of a fixed law, to which the phenomena are already
themselves subject, there could be no empirical synthesis
of reproduction.

There must, then, be something which makes even the
reproduction of phenomena possible, by being the a priori
foundation of a necessary synthetical unity among them.
But we very soon hit upon it when we reflect that pheno
mena are not things in themselves, but the mere play of
our representations, which are, after all, only determinations
of our internal sense. For if we can make it plain that
even our purest a priori intuitions afford us no knowledge,
except so far as they contain a combination of multiplicity
only to be produced by a thoroughgoing synthesis of
reproduction, then the synthesis of the imagination must
also be founded a priori on a principle prior to all
experience, and we must assume a pure transcendental
synthesis of the imagination, [197] which lies at the very
foundation of even the possibility of any experience (as that
which necessarily presupposes the possibility of reproducing
phenomena). Now, it is plain that if I draw a line in
thought, or think of the time from to-day at noon to to
morrow at the same hour, or even wish to represent to
myself any definite number, first of all I must necessarily
grasp in thought these manifold representations successively.
But if I lost out of mind, and could not reproduce the
earlier parts (the first part of the line, the prior portions of
the time, or the successively represented unities), whilst I
proceed to the succeeding ones, there never could arise a

197-198] DEDUCTION OF THE CATEGORIES 161

complete representation, nor any of the thoughts just
named — nay, not even the first and purest fundamental
representations ot space and time.

The synthesis of apprehension, then, is inseparably con
nected with that of reproduction. And as the former is
the transcendental foundation of the possibility of any
cognitions at all (not only of the empirical, but of the
pure a priori also), the reproductive synthesis of the ima
ginative faculty is one of the transcendental operations of
the mind ; and, in reference to these, we shall name this
faculty the transcendental imagination.1

3. Of the Synthesis of Recognition in the Concept. —
Without the consciousness that what we now think is
identical with what we thought a moment ago, all repro
ductions in the series of representations would be useless.
For what we now think would be a new representation
at the present moment, not at all belonging to the act by
which it should have been gradually pro- [198] duced ; and
the manifold thereof would never make up a totality,
because it must want that unity which consciousness alone
can give it. If in counting I were to forget that the units
which are now pictured to my senses were added by me
gradually to one another, I should not cognise the genera
tion of quantity by the successive addition of unit to unit,
nor, consequently, should I know number ; for this concept
consists essentially in the consciousness of the unity of the
synthesis.

The very word concept might of itself lead us to this
remark. For it is this one (single) consciousness which
unites the manifold, gradually intuited, and then also repro
duced into one representation. This consciousness, too,

1 I use the word imagination throughout for the faculty r, not for its
object, M.

162 APPENDIX A [198-199

may often be weak, so that we perceive it only in the
result and not in the act ; that is to say, we do not join
it immediately with the generating of the representation ;
but notwithstanding these distinctions, we must always
have one single consciousness, even though it does not
stand forth with striking clearness, and without it con
cepts (and consequently knowledge of objects) are quite
impossible.

And here it is necessary to make it clear what we mean
by the expression : object of representations. We have
said above, that phenomena are nothing but sensuous
representations, and these again must be considered in the
very same way, viz., not to be objects (beyond the faculty
of representation). What do we mean, then, when we
speak of an object corresponding to cognition, and yet
distinct from it ? It is easy to see that this object must
be thought as something in general = x, because outside
our cognition we surely possess nothing which we could
place over against it, as corresponding to it.

[199] But we find that our thought of the relation of
cognition to its object carries with it some sort of necessity,
since the object is considered to be that which prevents
our cognitions from being determined at random or capri
ciously, but a priori in some certain way, because, by being
referred to an object, they must also necessarily, in relation
to that object, agree among themselves ; that is to say,
they must have that unity which constitutes the concept of
an object.

But — since we are only concerned with the manifold of
our representations, and the x which corresponds to them
(the object), as it must be something different from our
representations, can be to us nothing — it is clear that the
unity which the object necessarily produces can be nothing

199-200] DEDUCTION OF THE CATEGORIES 163

else than the formal unity of consciousness in the synthesis
of the multiplicity of representations. We say then : ' we
cognise the object,' when we have produced in the manifold
of intuition synthetical unity. But this unity would be
impossible, unless we were able to produce the intuition
by means of such a function of synthesis according to rule
as renders necessary the reproduction of the manifold a
priori, and also a concept in which it is united. We think,
for example, of a triangle as an object, in that we are
conscious of the combination of three right lines according
to a rule by which such an intuition can at any time be
brought before us. This unity of the rule determines all
multiplicity, and limits it to conditions which make the
unity of a perception possible; and the concept of this
unity is the representation of object = x, which I think by
means of the aforesaid predicates of a triangle.

All cognition requires a concept, however incomplete
or obscure ; and this, in its very form, is something uni-
[2oo]versal, and which serves as a rule. So the concept
of body according to the unity of the manifold, which is
thought by means of it, serves as a rule for our cognition
of external phenomena. But it can only become a rule
of intuition by representing, along with given phenomena,
the necessary reproduction of their multiplicity, and con
jointly the synthetical unity in the consciousness thereof.
So the concept of body, when we perceive anything without
us, makes the representation of extension, and with it that
of solidity, figure, etc., necessary.

There is always a transcendental condition at the
foundation of any necessity. Hence, we must be able
to find a transcendental ground of the unity of conscious
ness in the synthesis of the manifold in all our intuitions,
and in all our concepts of objects generally — consequently,

164 APPENDIX A [200-201

in all objects of experience. Without this it would be im
possible to think any object as belonging to our intuitions ;
for such object is nothing else than, that something, of
which the concept expresses such a necessity of synthesis.

This original and transcendental condition is no other
than Transcendental Apperception. The consciousness
of self, according to the determination of our states in
internal perception, is merely empirical — always change
able ; there can be no fixed or permanent self in this
flux of our internal phenomena ; and this sort of con
sciousness is usually called the internal sense, or empirical
apperception. That which is necessarily represented as
numerically identical, cannot be thought as such by means
of empirical data. There must be a condition, anticipating
and rendering possible all experience. This condition
only can render valid such a transcendental assumption.

[201] Neither can cognitions take place in us, nor any
conjunction or unity among them, without this unity of
consciousness, which is prior to all the data of intuition,
and by reference to which alone all representation of
objects is rendered possible. This pure, original, un
changeable consciousness, I intend to call transcendental
apperception. That it deserves this name is plain from
the fact, that even the purest objective unity, namely,
that of a priori concepts (space and time), is only possible
by the reference of intuitions to such consciousness. The
numerical unity, then, of this apperception is just as much
the a priori basis of all concepts, as the multiplicity of
space and time is the basis of the intuitions of sensibility.

But this very transcendental unity of apperception
forms a connexion according to laws of all the possible
phenomena so far as they can come together in our experi
ence. For this unity of consciousness would be impossible

201-202] DEDUCTION OF THE CATEGORIES 165

if the mind, in the cognition of the manifold, were not
self-conscious of the identity of the function by means of
which it connects this manifold synthetically in a cognition.
Consequently, the original and necessary consciousness of
the identity of self is at the same time a consciousness of
just as necessary a unity of the synthesis of all phenomena
according to concepts; that is, according to rules which
not only make the phenomena necessarily reproducible,
but ipso facto also determine an object for (their) intuition,
and this object is a concept of something in which they
are necessarily connected. For the mind could not pos
sibly think its own identity in the multiplicity of repre
sentations, and this too a priori, if it had not before its
eyes (so to speak) the identity of its own action, which
subjects all the [202] empirical synthesis of apprehension
to a transcendental unity, and is the necessary condition of
the connexion of this apprehension according to rules.
We shall now be able to determine more correctly our
notion of an object All representations have, as such, their
object, and may themselves also become the objects of
other representations. Phenomena are the only objects
which can be given us immediately, and that which in the
phenomenon refers immediately to the object is called
intuition. These phenomena are not things per se, but
themselves only representations, which, again, have their
object, and this we can no longer intuite ; it may therefore
be called the non-empirical, or transcendental object = x.

The pure concept of the transcendental object (which
is really in all our cognitions of the same sort = x) is that
which can obtain for all our empirical concepts in general
reference to an object — that is, objective reality. Now
this concept can contain no determinate intuition, and
can therefore refer to nothing but that unity which must

1 66

APPENDIX A

[202-203

be found in the multiplicity of a cognition, so far as it
stands in relation to an object. But this relation is
merely the necessary unity of consciousness, and also of
the synthesis of the manifold by a general function of
the mind, which connects the manifold into one repre
sentation. Since this unity must be regarded as necessary
a priori (otherwise the cognition would have no object),
the relation to a transcendental object — that is, the ob
jective reality of our empirical knowledge — depends on the
transcendental law, that all phenomena (so far as objects
are to be given us through them) must submit to the a
priori rules of their synthetical unity, according to which
their relation in empirical intuition is alone possible.

[203] In short, phenomena must in experience stand
under the conditions of the necessary unity of apperception,
just as they must stand in mere intuition under the formal
conditions of space and time ; so that only through the
former does any cognition become even possible.

4. Preliminary Explanation of the Possibility of the
Categories as a priori Cognitions. — There is only one ex
perience, in which all perceptions are represented in
thoroughgoing and regular connexion ; just as there is
only one space and one time in which all forms of pheno
mena, and all relations of existence or non-existence,
are found. When we speak of different experiences, they
only mean so many perceptions, as far as they belong to
one and the same universal experience. The thorough
going and synthetical unity of perceptions is exactly what
constitutes the form of experience, and experience is
nothing but the synthetical unity of phenomena according
to concepts. Unity of synthesis according to empirical
concepts would be quite contingent ; and, were these not
based on a transcendental ground of unity, it would be

203-204] DEDUCTION OF THE CATEGORIES 167

possible for a confused crowd of phenomena to fill our
minds, without our ever forming experience from them.
But then all reference of cognition to objects must vanish,
because the connexion of experience according to universal
and necessary laws would be wanting ; we should then
have thoughtless intuition, never amounting to knowledge,
and so for us equivalent to nothing.

The a priori conditions of any possible experience are,
at the same time, the conditions of the possibility of the
objects of experience.1 Now I assert that the above-
mentioned [204] Categories are nothing but the conditions
of thinking in possible experience, just as space and time are
the conditions of the intuition which is requisite for the
same. The former, then, are likewise fundamental concepts
which enable us to think objects in general for phenomena,
and are, accordingly, objectively valid — the very point we
wished to ascertain.

But the possibility, nay even the necessity, of these
Categories depends upon the relation in which the whole
sensibility, and with it all possible phenomena, must stand
to primitive apperception; in which apperception everything
must necessarily accord with the conditions of the thorough
going unity of self-consciousness, which means that every
thing must be subject to universal functions of synthesis —
synthesis according to concepts. By this means alone can
apperception prove its thoroughgoing and necessary identity.
For example, the concept of cause is nothing but a synthesis
(of that which follows in the series of time with other

1 That is to say, the [subjective] conditions of our minds, whereby
alone we become capable of knowing objects, must also be the only
possible [and therefore necessary] conditions of objects ; for without
submitting to these conditions, the objects cannot exist at all. It is
idle to add for us, since no noumenon can properly be called an
object. M.

1 68 APPENDIX A [204-205

phenomena) according to concepts, and without such a
unity, which has its rule a priori and controls the pheno
mena, thoroughly universal and necessary unity of conscious
ness could not occur in the multiplicity of phenomena : in
which case these phenomena would belong to no experience,
and therefore be without any object, but only a random
play of representations, less even than a dream.

All attempts, then, to deduce from experience these [205]
pure concepts of the understanding, and to give them a
merely empirical origin, are perfectly idle and useless.
I waive the point that the concept, for example, of cause
carries with it the feature of necessity, which could not be
given by any experience, for this indeed teaches us, that
something usually follows a certain phenomenon, but never
that it must follow necessarily ; nor could it teach us that
we may conclude a priori, and quite universally, from the
cause as a condition, to the effect. But this empirical rule
of association, which we must of course assume as uni
versally applicable, when we say that everything in the
series of events is so strictly obedient to law, that nothing
happens without being preceded by something upon which
it always follows — this rule I say, as a law of nature, upon
what does it depend ? How, I ask, is this association even
possible? The foundation of the possibility of this as
sociation of the manifold, as far as it lies in the object, is
called the affinity of the manifold. I ask, then, what
makes this thoroughgoing affinity of phenomena conceivable
to you (by which they stand under, and must be subject to
permanent laws) ?

Upon my principles it is easily understood. All possible
phenomena belong, as representations, to the whole of
possible self-consciousness. But this being a transcend
ental representation, its numerical identity is indivisible

205-206] DEDUCTION OF THE CATEGORIES 169

and certain a priori, because we cannot possibly know
anything, except through this primitive apperception. Now,
as this identity must necessarily be introduced into the
synthesis of all the manifold of phenomena, which are ever
to become empirical cognition, the phenomena must be
subject to a priori conditions, to which their synthesis (in
apprehension) must thoroughly [206] conform. The re
presentation of a general condition, according to which a
certain multiplicity can be brought before us (that is to say,
a definite way of doing it), is called Rule ; if it must be so
brought before us, Law. Consequently all phenomena
stand in thorough connexion with one another according
to necessary laws, and hence in a transcendental affinity r, of
which the empirical is merely the consequence.

That nature must conform to OUT subjective apperception
— nay, even that its order must depend on this relation —
probably sounds very absurd and strange. But if we reflect
that this nature is nothing in itself but the sum -total of
phenomena, consequently nothing per se, but merely a
number of mental representations, we need not be surprised
that we see it subject to the radical faculty of all our
knowledge; that is to say, subject to transcendental ap
perception, and hence subject to that unity through which
alone it can become the object of any possible experience ;
or, in other words, become nature. It is for the very same
reason that we can cognise this unity a priori, and therefore
necessarily, which would be impossible were it given in
itself, independent of the highest sources of our thinking.
In this latter case, I know not whence we could draw the
synthetical propositions of such a universal unity of nature;
for then we must borrow them from the objects of nature
themselves. As this could only be done empirically,
nothing could be inferred but a contingent unity, which

II N

1 7o APPENDIX A [206-207

is very far from being the necessary connexion which we
mean by the word nature.

[207] § 3. Of the Relation of the Understanding to Objects in
general, and of the Possibility of Cognising them a priori.

The detached observations made in the previous section
we shall here unite and present in a connected form. There
are three subjective sources of cognition, upon which rest
the possibility of experience in general, and the cognition
of objects ; these are Sense, Imagination, and Apperception.
Each of these can be considered empirically, that is, in its
application to given phenomena ; but all of them are also
[original] elements [of the mind], and a priori conditions,
which make even this empirical use possible. Sense
represents phenomena empirically in perception; Imagination,
in association (and reproduction) ; Apperception, in the em
pirical consciousness of the identity of these reproduced
representations with the (original) phenomena, that is to
say, in Recognition. But at the a priori basis of the whole
of our perceptions lie pure intuitions (or if we regard them
as representations — the form of internal intuitions, time).
At the basis of association lies the pure synthesis of the
imagination ; and at the basis of empirical consciousness,
pure apperception, that is, the thoroughgoing identity
of self in all possible representations. If we wish, then, to
analyse the internal causes of this connexion of representa
tions, till we reach the point where all representations must
meet (in order to start with unity of cognition, which is the
necessary condition of possible experience), we must begin
from pure apperception. All intuitions are for us nothing,
and do not the least concern us, if they cannot be taken up
into consciousness, whether directly or indirectly, and only

207-209] DEDUCTION OF THE CATEGORIES 171

through this means is cognition at all possible. We are
a priori conscious of our own complete [208] identity in
regard to all representations which can ever belong to our
cognition; and this we regard as the necessary condition
of the possibility of all representations. (For these only
represent anything in me, by belonging, with all the rest, to
one consciousness, in which they can at any rate be con
nected.) This principle is established a priori^ and may
be called the transcendental principle of the unity of all
multiplicity in our representations (even in intuition).
Now, the unity of multiplicity in one subject is synthetical.
Pure apperception, then, gives us a principle of the syn
thetical unity of multiplicity in all possible intuition.1

[209] But this synthetical unity presupposes or implies

1 Let us pay particular ^'attention to this proposition, which is of the
greatest importance. All representations have a necessary reference to
a possible empirical consciousness ; for if they had not this feature,
and were it quite impossible to become conscious of them, this would
mean that they do not exist. But all empirical consciousness has a
necessary reference to a transcendental consciousness (preceding all
particular experience), namely, the consciousness of self, as the primi
tive apperception. It is absolutely necessary that in my cognition all
[acts of] consciousness should belong to one consciousness (of myself).
Now this is a synthetical unity of the manifold (of consciousness) which
is cognised a priori, and which gives just the same basis for synthetical
a priori propositions which relate to pure thinking, as space and time
give to such propositions as relate to the form of mere intuition. The
synthetical proposition, that the various empirical consciousnesses must
be combined in one single self-consciousness, is absolutely the first and
synthetical principle of our thinking in general. But we must never
forget, that the bare representation Ego is the transcendental conscious
ness in relation to all others (the collective unity of which it renders
possible). This representation may then be clear (empirical conscious
ness) or obscure — a fact which is here of no importance ; nay, not even
the fact whether it have any actuality or not ; but the possibility of the
logical form of all knowledge rests necessarily on the relation to this
apperception as a faculty.

i;2 APPENDIX A [209-210

a synthesis ; and if the former is to be necessary a priori,
the latter must be an a priori synthesis. Consequently,
the transcendental unity of apperception points to the pure
synthesis of imagination, as an a priori condition of the
possibility of any combination of the manifold into a single
cognition. But it is only the productive synthesis of the
imagination which can take place a priori ; for the repro
ductive depends on empirical conditions. Consequently,
before apperception, the principle of the necessary unity of
the pure (productive) synthesis of the imagination is the
foundation of the possibility of any knowledge, especially
of experience.

We denominate the synthesis of multiplicity in the
imagination transcendental, when, without distinguishing
the intuitions, it aims at nothing but the combination of
multiplicity a priori : and the unity of this synthesis is
called transcendental, if, as referring to the original unity
of apperception, it is represented as necessary a priori.
Now, as this latter lies at the foundation of all cognitions,
the transcendental unity of the synthesis of the imagination
is the pure form of all possible cognition, by means of
which all objects of possible experience must be represented
a priori.

The unity of apperception in relation to the synthesis of
the imagination is the understanding ; and this very unity,
in relation to the transcendental synthesis of the [210]
imagination, is the pure understanding. There are, then,
in the understanding pure cognitions a priori which contain
the necessary unity of the pure synthesis of the imagina
tion, in reference to all possible phenomena. But these
are the Categories, or pure concepts of the understanding.
Consequently, the empirical faculty of cognition which
belongs to our nature contains an understanding which

210-21 1] DEDUCTION OF THE CATEGORIES 173

relates to all objects of the senses, but this only
mediately, through intuition and its synthesis by means of
the imagination, to which understanding all phenomena
must consequently be subject, as data for a possible ex
perience. But, as this relation of phenomena to possibly
experience is also necessary (because without this they
would afford us no cognition, and not concern us at all)
it follows, that the pure understanding, by means of the
Categories, is a formal and synthetical principle of all
experiences, and phenomena have a necessary relation to
the understanding.

We shall now expound the necessary connexion of the
understanding with phenomena by means of the Categories,
by beginning from below — from the empirical extremity.
The first thing given us is the phenomenon, which, if
combined with consciousness, is called perception. (With
out relation at least to a possible consciousness, the pheno
menon could never be for us an object of cognition, and
would hence be to us as nothing ; having no . objective
reality, and only existing as known, it would be absolutely
nothing at all.) But as every phenomenon contains a
certain multiplicity — that is to say, as various perceptions
are found within us, in themselves scattered and single — a
connexion of them is necessary, and this they cannot have
in mere sense. There is, then, within us an active faculty
of the [211] synthesis of this multiplicity, which we call
the faculty of Imagination ; and the action of which, when
directed immediately upon the perceptions, I call appre
hension.1 The province of the imagination is to unite the

1 That the faculty of imagination is a necessary ingredient even in
perception, has perhaps not as yet struck any psychologist. This
arises partly from confining the faculty to mere reproductions; partly
because it was thought that the senses not only gave us impressions,

174 APPENDIX A [211-212

manifold of intuition into an image ; it must first, then,
grasp the impressions actively, viz. apprehend them.

But it is clear that even this apprehension of the
manifold by itself could produce no image, nor connexion
of impressions, if there were not present a subjective con
dition for summoning a perception from which the mind
had made a transition to the next, to join this next, and so
produce whole series of these perceptions — in fact, if we
did not possess a reproductive faculty of the imagination,
which even then is only empirical. But representations, if
they suggested one another just as they chanced to meet
together originally, would have no determinate connexion,
but be a mere confused crowd, from which could spring
no cognition ; their reproduction must therefore have a
rule by which a representation enters into combination
rather with this than with another representation in the
imagination. The subjective and empirical ground of re
production according to rules, we call the association of
representations.

[212] But if this unity of association had not also an
objective basis, so as to make it impossible for phenomena
to be apprehended by the imagination except under the
condition of a possible synthetical unity of this apprehension,
then it would also be quite contingent that phenomena,
when combined, should be adapted to human cognitions.
For although we had the faculty of associating perceptions,
it would still be quite undetermined in itself, and acci
dental, whether they were also themselves capable of such
association ; and supposing they were not, a quantity of

but even combined them, and so brought images of objects before us
— a process which, nevertheless, most certainly requires somewhat
besides the mere receptivity of impressions, namely, a function of their
synthesis.

212-213] DEDUCTION OF THE CATEGORIES 175

perceptions, and even a whole sensibility, would be possible,
in which the mind might meet with a great deal of em
pirical consciousness, but disconnected, and without belong
ing to one consciousness of myself, which is nevertheless im
possible. For it is only when I attribute all my perceptions
to one consciousness (of pure apperception) that I can
say I am conscious of them. There must, then, be an
objective ground prior to any of the empirical laws of
imagination, and a priori, on which depends the possibility
— nay, even the necessity — of a law extending over all
phenomena; which regards them universally to be such
data of the senses as are in themselves associable, and
subject to the general rules of a thoroughgoing connexion
when reproduced. This objective basis of all association
of representations I call affinity. We cannot meet it else
where than in the principle of the unity of apperception, as
regards all cognitions which can belong to me. According
to this principle, every phenomenon without exception
must so enter the mind, or be apprehended, as to agree
with the unity of apperception, which apperception would
itself be impossible without synthetical unity in its [213]
connexion ; this latter is, accordingly, also objectively
necessary.

The objective unity of all (empirical) consciousness
in one consciousness (of primitive apperception) is then
the necessary condition even of all possible perception ; and
the affinity of all phenomena (proximate or remote) is the
necessary consequence of a synthesis in the imagination,
which is founded a priori upon rules.

The Imagination is then also a faculty 01 a priori
synthesis, for which reason we give it the name of the
productive imagination ; and since, as far as it relates to
the multiplicity of phenomena, it has no further object

I76 APPENDIX A [213-214

than to produce the necessary unity in their synthesis, we
may call it the transcendental function of the imagination.
It is then sufficiently clear from what precedes, though it
may sound rather strange, that only by means of the
transcendental function of the imagination does even the
affinity of phenomena, and with it their association, and
through this, too, their reproduction in accordance with
laws — in fact, does experience — become possible ; because
without it no concepts of objects would ever coalesce into
one experience.

For the fixed and unchanging Ego (of pure apperception)
constitutes the correlatum of all our representations, so far
as it is merely possible to become conscious of them;
and all consciousness belongs just as much to an all-com
prehensive pure apperception as all sensuous intuition (qua
representation) belongs to a pure internal intuition —
namely, that of time. It is, then, this apperception which
must be added to the imagination, to render its function
intellectual. For in itself the synthesis of imagination,
though exercised [214] a priori, is yet always sensuous,
because it only combines the manifold as .it appears in
intuition — for example, the figure of a triangle. But it is
only through the relation of the manifold to the unity of
apperception that concepts can be formed, and this only
by means of the imagination in relation to the sensuous
intuition.

We have then the pure imagination, as an original
faculty of the human soul, lying at the basis of all cogni
tion a priori. By means of it we bring on the one side
the multiplicity of intuition, and on the other the condition
of the necessary unity of apperception, into mutual relation.1

1 From this point I have developed my explanation of the schematism
of the Categories. M.

214-215] DEDUCTION OF THE CATEGORIES 177

Both extremities — sensibility and understanding — must be
necessarily connected by means of this transcendental
function of the imagination ; otherwise, there might indeed
be appearances, but no objects of empirical cognition, or
experience. Actual experience, consisting of apprehension,
association (of reproduction), and finally, of the recognition
of phenomena, contains in this last and highest (merely
empirical element of experience) concepts, which render
possible the formal unity of experience, and with it all
objective validity (truth) of empirical cognition. These
fundamental causes of the recognition of multiplicity, so
far as they concern merely the form of experience in general,
are the very categories of which we are speaking. On
them is founded not only all formal unity of the synthesis
of the imagination, but through it the unity even of all
that belongs to its empirical use (in recognition, repro
duction, association, apprehension) down to phenomena;
because it is only by means of [215] these elements of our
knowledge that phenomena can belong to our conscious
ness, and hence to ourselves.

Thus the order and regularity in phenomena, which we
call nature, we ourselves introduce, and should never find it
there, if we, or the nature of our mind, had not originally
placed it there. For this unity of nature must be a ne
cessary unity of connexion, that is to say, certain a priori.
But how could we possibly produce a priori a synthetical
unity, if subjective foundations for such unity a priori
were not contained in the original sources of knowledge in
our mind, and if these subjective conditions were not at
the same time objectively valid, by being the very basis of
the possibility of cognising any object at all in experience ?

We have already explained the Understanding in various
ways : by a spontaneity of cognition (as opposed to the

i;8 APPENDIX A [215-216

receptivity of sensibility), or by a faculty of thinking, or of
concepts, or even of judgments — all of which explanations,
if properly understood, coincide. We may now characterise
it as the faculty of rules. This attribute is more fruitful,
and explains its * nature better. Sensibility gives us forms
(of intuition), but the understanding gives us rules. This
latter is always occupied in hunting through phenomena,
in order to find any rule they may present. Rules, so far
as they are objective (or belong necessarily to the cognition
of the object) are called laws. Although we learn many
laws from experience, yet are these only particular deter
minations of higher laws, among which the highest (to
which the rest are subordinate) are derived from the [216]
Understanding itself, and are not borrowed from experi
ence, but rather render phenomena subject to law, and by
this very means make experience itself possible. The
understanding is, then, not merely a faculty of forming for
itself rules by the comparison of phenomena ; it is itself a
code of laws for nature, that is to say, without the under
standing there would be no nature at all, or synthetical
unity of phenomena according to rules ; for phenomena
cannot, as such, find place without us, but exist only in our
sensibility. But this [sensibility], as an object of know
ledge in experience, with all that it may contain, is only
possible in the unity of apperception. This unity of apper
ception is the transcendental basis of the necessary regu
larity of all phenomena in experience. The same unity in
relation to the multiplicity of representations (that is to
say, determining it from a single representation) is the rule,
and the faculty of these rules is the understanding. Thus
all phenomena, as possible objects of experience, lie a

1 The original is derselben, viz. their (the rules) nature. My
emendation, desselben, seems necessary. M.

2i6-2i7l DEDUCTION OF THE CATEGORIES 179

priori in the understanding, and receive from it their
possibility, just as mere intuitions lie in the sensibility,
and, as to form, are only possible through it.

However exaggerated or absurd, then, it may seem to
assert that the understanding itself is the source of the
laws of nature, and of the formal unity thereof, such an
assertion is nevertheless equally correct and applicable to
the object, that is, to experience. Empirical laws, indeed,
as such, can by no means deduce their origin from the pure
understanding, just as the infinite variety of phenomena
could not be adequately conceived from the pure form of
sensuous intuition. But all empirical laws are only par
ticular determinations of the pure laws of the understanding,
under which, and ac- [217] cording to the type of which,
they first become possible ; so that phenomena assume a
fixed form, just as all phenomena, in spite of the variety
of their empirical form, must nevertheless always accord
with the conditions of the pure form of sensibility.

The pure understanding is, then, in the Categories, the
law of the synthetical unity of all phenomena ; and hence
it first renders experience possible as to form.1 But this
was our whole aim throughout the transcendental deduction
of the Categories, namely, this relation of the understanding
to sensibility, and through it to all objects of experience ;
in fact, to render intelligible the objective validity of the
pure concepts of the understanding, and so to establish
their origin and truth.

1 This important limitation saves Kant's system from absolute
idealism. He never asserts that the matter of experience is created
by the Ego. M.

i8o APPENDIX A [217-218

SUMMARY STATEMENT OF THE CORRECTNESS AND POS
SIBILITY OF THIS AND NO OTHER DEDUCTION OF THE

PURE CONCEPTS OF THE UNDERSTANDING.

WERE the objects with which our knowledge is concerned
things in themselves, we could not have any a priori
concepts of them. For from whence could we obtain such
concepts ? Suppose we took them from the object (without
pausing to investigate how this could become known to us
at all), then our concepts would be [218] merely empirical,
and not a priori. Suppose we took them from ourselves,
then that which is merely within us could not determine
the nature of an object distinct from our representations ;
that is to say, it could not form a reason why there should
exist a thing to which our thoughts should correspond,
rather than that such representations should be totally void.
On the contrary, if we are altogether concerned only with
phenomena, it is not only possible, but even necessary,
that certain a priori concepts should antecede the empirical
cognition of objects. For, as phenomena, they produce an
object which exists only in us, because a mere modification
of our sensibility cannot exist without us. Now this very
representation — that all these phenomena, and objects with
which we can employ ourselves, are all in me, that is, are
determinations of my identical self — this representation,
I say, expresses their complete unity in one and the same
apperception to be necessary. But in this unity of possible
consciousness consists also the form of all cognition of
objects (by which multiplicity is thought as belonging to
one object). So that the way in which the manifold of
sensuous representations (intuition) belongs to one con
sciousness, precedes all cognition of the object, as being its
intellectual form, and even produces a formal cognition of

218-219] DEDUCTION OF THE CATEGORIES 181

all objects a priori, so far as they are thought (Categories).
Their synthesis through the pure imagination, and the
unity of all representations in relation to primitive appercep
tion, precede all empirical cognition. Consequently, all
pure concepts of the understanding are only for this reason
possible — nay, even in relation to experience, necessary —
that our knowledge is concerned with no- [219] thing but
phenomena, the possibility of which lies within ourselves,
and the conjunction and unity of which (in the representa
tion of an object) are to be found only in ourselves ; so
that these must precede all experience, and make it even
possible as to form. It is then on this, the only possible
basis, that our deduction of the Categories has been con
structed.

[220] APPENDIX B

DISTINCTION BETWEEN NOUMENA AND
PHENOMENA

(a.) AFTER the words 'under such conceptions,' p. 181
(Meiklejohn's translation), the following paragraph occurs in
the First Edition : —

' Above, in the exposition of the table of the Categories,
we saved ourselves the trouble of denning each of them,
because our object, which concerned merely their synthetical
use, did not require it, and we should not, by needless
undertakings, incur responsibilities which we can avoid.
This was not an evasion, but an unavoidable rule of pru
dence, not to venture forthwith into definitions, and to
attempt or pretend to completeness in the determination
of -a concept, when one or two of its attributes suffice,
without our requiring a complete enumeration of all that
make up the whole concept. But it now appears that the
ground of this precaution lies deeper, namely, that we
could not define them if we wished to do so.1 For, if we

1 I mean here real definition, which does not merely substitute for
the name of a thing other more intelligible terms, but that which
contains in it a distinct attribute by which the object (definitum] can
always be certainly recognised, and which renders the defined concept
useful in application. The real explanation would then be that which

220-222] NOUMENA AND PHENOMENA 183

get rid of all the [221] conditions of sensibility which mark
them as concepts that can possibly be used empirically,
and take them for concepts of things in general (that is, of
transcendental application), then nothing further can be
done with them than to regard the logical function in
judgments as the condition of the possibility of things
themselves ; without there being the least evidence how
they could then have their application and object, or how
they could then have any meaning and objective validity in
the pure understanding, apart from sensibility.'

(/?.) Instead of the note on p. 182, the First Edition
has the following : —

' It appears somewhat strange, and even absurd, that
there should be a concept which is to have a signification
but is not capable of any explanation. But the Categories
are here so peculiarly circumstanced that, though they can
only have a definite signification and reference to any
object by means of the universal sensuous condition, yet this
condition has been left out of the pure Category, which in
consequence can contain nothing but the logical function
of bringing the manifold under a concept. But from this
function — that is, from the form of the concept alone — it
cannot at all be known what object falls under it, because
abstraction has been made from that very sensuous con
dition, owing to which alone objects in general can come
under the [222] Category. Hence the Categories require,
beyond the mere concept of the understanding, determina
tions of their application to sensibility in general (schemata},
and without this are not concepts by which any object can
be cognised and distinguished from another : they are rather

makes distinct not only a concept, but at the same time its objective
reality. Mathematical explanations, which present the object in accord
ance with the concept in intuition, are of this latter sort.

1 84 APPENDIX B [222-223

so many ways of thinking an object for possible intuitions,
and giving it its signification (under conditions yet to be
supplied), according to some function of the understanding,
that is, of defining it : but these Categories cannot them
selves be defined. The logical functions of judgments in
general — unity and plurality, affirmation and negation,
subject and predicate — cannot be defined without arguing
in a circle, because such definition cannot but be a
judgment, and must therefore contain these functions.
But the pure Categories are representations of things in
general, so far as the diversity of their intuition must be
thought through one .or other of these logical functions :
Quantity is the determination which can only be thought
through a judgment having quantity (judidum commune} ;
Reality, that which can only be thought through an affirma
tive judgment ; Substance, that which, in reference to
intuition, must be the ultimate subject of all other deter
minations. But what sort of things they are, in reference
to which we must employ this function rather than that,
still remains quite undetermined. So that the Categories,
without the condition of sensuous intuition (provided they
contain the synthesis), have no definite relation to any
object, hence cannot define any such object, and have not,
consequently, in themselves the validity of objective con
cepts.'

The passage commencing 'but there lurks' (p. 184),
and ending ' negative sense ' (p. 186), was re-written [223] in
the Second Edition. Its original form was as follows : —

'Appearances, so far as they are thought as objects,
according to the unity of the Categories, are called pheno
mena. But if I assume things, which are merely the objects
of the understanding, and which can, at the same time, be
presented to an intuition, though not a sensuous one (as

223-224] NOUMENA AND PHENOMENA 185

coram intuitu intellectual}), then such things would be called
noumena (intelligibilia).

Now it might be imagined that the concept of phenomena,
limited as it was in the transcendental Aesthetic, suggests
of itself the objective reality of the noumena, and justifies
the division of all objects into phenomena and noumena ;
and so of the world into one of sense and reason (nmndus
sensibilis et intelligibilis). And indeed the difference would
not seem to be the logical form of the distinct or indistinct
knowledge of one and the same object, but would start from
the difference of the way in which they are given to our
cognition, and according to which they must differ from
one another in themselves generically. For if the senses
represent something only as it appears, this something must
surely be also a thing in itself, and the object of a non-
sensuous intuition, that is, of the understanding. In such
case there must be a cognition possible, in which no sensi
bility can be found, and which alone possesses absolutely
objective reality, viz. by which objects are represented to
us as they are ; whereas, on the contrary, in the empirical
use of our understanding, things are only cognised as they
appear. Accordingly, beyond the empirical use of the
Categories (which is restricted to sensuous conditions),
there would be still [224] a pure and objectively valid one;
and we could not assert, as we have claimed to do so far,
that our pure understanding-cognitions are nothing but
principles of the exposition of appearance, and do not
reach any further a priori than the formal possibility of
experience ; for here quite another field would lie open to
us, as it were a world thought in the spirit (perhaps even
intuited), upon which we could employ our understanding
just as much, and far more nobly.

Now all our representations are, in fact, referred to some

II O

1 86 APPENDIX B [224-223

object by the understanding, as phenomena are nothing
but representation ; and so the understanding refers them
to something, as the object of sensuous intuition ; but this
something is so far merely the transcendental object. But
this signifies a something = x, of which we know nothing ;
nor can we (according to the present constitution of our
understanding) know anything of it, as being that which
can serve only as a correlate of the unity of apperception to
obtain the unity of diversity in sensuous intuition, by means
of which the understanding unites this diversity in the
concept of an object. This transcendental object cannot
be at all separated from the sensuous data, because then
nothing remains by which it would be thought.1 [223]
[This x then] is no object of cognition in itself, but only
the representation of phenomena under the concept of an
object in general, which is determinable by the diversity of
the phenomena.

For this reason, the Categories do not represent any
definite object given to the understanding alone, but only
serve to determine the transcendental object (the concept
of something in general), by what is given in sensibility, so
as by it to cognise empirically phenomena under concepts
of objects.

But as to the reason why we (not satisfied with the
substratum of sensibility) have added noumena to the

1 This clause Kuno Fischer omits in his account of the matter
(Cotnm. p. 131), though it explains and limits Kant's meaning, in the
passages quoted by him (pp. 190 and 195) in italics. Because nothing
is left for us, when we subtract all the subjective conditions of the
object, it does not follow that nothing at all remains. Hence, through
out this passage Kant never asserts the thing per se not to exist. His
private opinion seems to have been that it did exist ; and this is often
implied in his language, though not dogmatically stated, being just as
indemonstrable as the opposed doctrine. M.

223-224] NOUMENA AND PHENOMENA 187

phenomena, which the pure understanding alone can think,
it rests simply upon this : Sensibility and its sphere (viz.
that of phenomena) are restricted by the understanding to
this, that they shall concern not things per se, but only the
way in which things appear to us according to our sub
jective constitution. This was the result of the whole
transcendental Aesthetic ; and it also follows naturally from
the very concept of a phenomenon in general, that some
thing must correspond to it which in itself is not pheno
menon, because phenomenon can be nothing in itself
beyond our faculty of representation; so that, unless we
are involved in a perpetual circle, the very word phenomenon
indicates a reference to something, the immediate representa
tion of which indeed is sensuous, but which in itself, even
without this constitution of our sensibility (upon which the
form of our intuition is based), must still be some- [224]
thing, that is, an object independent of our sensibility.

Now from this originates the concept of a noumenon,
which is, however, not at all positive, or a definite cognition
of any particular thing, but only signifies the thought of
something in general, by abstracting from all the form of
sensuous intuition. But in order that a noumenon should
signify a true object, to be distinguished from all phenomena,
it is not enough for me to rid my thoughts of all the con
ditions of sensuous intuition ; I must, over and above this,
have some reason for assuming another sort of intuition
than sensuous, to which such an object could be given :
otherwise my thought, though not self-contradictory, is still
void. We have, indeed, not been able to demonstrate in
the text that sensuous intuition was the only possible one
whatever, but merely that it was so for us ; but neither
were we able to prove that any other kind of intuition was
possible ; and although our thought can abstract from all

!88 APPENDIX B [224-225

sensibility, the question still remains to be settled — whether
it is then anything but the mere form of a concept ; and
whether, when such abstraction is made, any object at all is
left.1

The object to which I refer the phenomenon in general
is the transcendental object, that is, the totally unde
termined thought of something in general. This [225]
cannot be called the noumenon ; for I do not know what it
is in itself, and have no concept of it at all, except as the
object of sensuous intuition in general, which is, accordingly,
of the same description for all phenomena. I cannot think
it by means of any Category ; for such is valid only of
empirical intuition, in order to subject it to the concept of
an object in general. A pure use of the Categories is
indeed possible, or not contradictory, but has no objective
validity, because it concerns no intuition on which it
confers the unity of an object; for the Category is only
a pure function of thought, by which no object can be
given me, but by which I only think what is given in
intuition.

1 Here is the question of absolute idealism explicitly raised ; and the
following paragraph proceeds, not to solve it dogmatically, but merely
to show that no possible data can be found for settling the question.
There being such total absence of proofs, may not the necessary
suggestion of noumena by phenomena be allowed some weight ? M.

[226] APPENDIX C

THE FIRST PARALOGISM OF SUBSTANTIALITY 1

THAT of which the representation is the absolute subject
of our judgments, and which consequently cannot be used
to determine anything else [as predicate], is substance.

I, as a thinking being, am the absolute subject of all my
possible judgments, and this representation of myself cannot
be used as the predicate of anything else.

Therefore I, as a thinking being (soul), am substance.

KRITIK OF THE FIRST PARALOGISM OF PURE
PSYCHOLOGY

We have shown in the analytical part of the transcend
ental Logic that pure Categories (and among them that of
Substance) have in themselves no objective meaning at all,
except when based on an intuition, to the di- [227] versity
of which they can be applied, as functions of the synthetical
unity. Without this, they are merely functions of judgment,
without content. Of anything in general, I may say it is
substance, so far as I distinguish it from the mere predicates
and determinations of things. Now in all our thinking, the

1 The following discussion stood in the First Edition after the words
' predicaments of pure psychology ' (p. 241).

190 APPENDIX C [227-228

Ego is the subject, in which thoughts inhere merely as
determinations, and this Ego cannot be used to determine
anything else. Consequently, every one must necessarily
consider himself as the substance, and his thoughts as the
accidents, of his existence, and determinations of his
condition. But what use can I make of this notion of a
substance ? That I, as a thinking being, exist permanently ;
that I cannot naturally either originate or pass away — this
I cannot at all infer from it, and yet it is the only use of
the concept of the substantiality of my thinking subject,
with which I could otherwise very well dispense.

We are so far from being able to conclude these
properties from the mere pure Category of substance, that
we are obliged to start from the permanence of an object
derived from experience, if we wish to bring such an object
under the empirically applicable concept of substance. Now,
in the proposition we are discussing, we have not taken any
experience for our basis, but have drawn our conclusion
simply from the concept of the relation which all thought
has to the Ego, in which it inheres, as its common subject.
Neither could we, supposing we desired to do it, establish
such a permanence by any safe observation. For the Ego
is present indeed in all thoughts; but there is not the
least intuition connected with this representation, to dis
tinguish it from other objects of intuition. We may then
indeed perceive that this representation is ever recurring in
every act of [228] thought, but not that it is the fixed and
permanent intuition in which thoughts (being transient)
alternate.1

1 He here approaches as closely as possible to the refutation of
idealism in his Second Edition. According to the First Edition also,
all change must take place in a permanent, [and (Second Edition) a
permanent homogeneous with it]. This permanent is not the Ego

228-229] PARALOGISMS OF RATIONAL PSYCHOLOGY 191

It follows, that the first syllogism of transcendental
psychology only palms off upon us a pretended discovery,
by setting up the constant logical subject of thinking as
the cognition of the real subject of inherence. Of this
latter we neither have, nor can have, the least knowledge,
because consciousness is the only thing which makes all
our representations thoughts, and wherein all our perceptions
must be found, as their transcendental subject ; and beyond
this logical meaning of the Ego, we have no knowledge of
the subject in itself, which lies as substratum at the basis of
this [representation of self], as well as of all other thoughts.
The proposition, then, the soul is a substance, may be
allowed to stand, provided we keep in mind that this notion
leads us no further, and cannot teach us any of the
usual conclusions of sophistical psychology ; for example,
its permanence through all changes, and even after death.
It denotes then a substance only in Idea, but not in
reality.

THE SECOND PARALOGISM, OF SIMPLICITY

A thing, of which the action cannot be regarded as the
concurrence of the action of several things, is simple.
[229] Now the soul, or thinking Ego, is such a thing.
Therefore, etc.

KRITIK OF THE SECOND PARALOGISM OF TRANSCEND
ENTAL PSYCHOLOGY

This is the Achilles of all the dialectical syllogisms of
pure psychology ; not merely a play of sophistry ingeniously
contrived by the dogmatical philosopher, to produce some

[ (First Edition, above ; ) ] therefore, it must be an external permanent
(Second Edition). M.

192

APPENDIX C [229-230

show of argument for his assertions, but a conclusion which
seems to withstand the most acute investigation, and the
most circumspect consideration. Here it is : —

Every composite substance is an aggregate of many ; and
the action of any composite, or that which inheres in it as
such, is the aggregate of many actions or accidents, divided
among a number of substances. Now, an effect which
arises from the concurrence of several acting substances
is possible when this effect is merely external (as, for
instance, the motion of a body is the joint motion of all its
parts). But the case is different with thoughts, which are
accidents belonging internally to a thinking being. For
supposing that this composite did think, each part of it
would contain part of the thought ; but all of them only
when combined, the whole thought. Now this is con
tradictory. For since the representations which are con
tained under the different parts (suppose the individual
words of a verse) are never [by themselves] a whole thought
(a verse), so thought cannot be inherent in a composite as
such. Thought, therefore, is only [230] possible in a
substance which is not an aggregate of many substances,
but absolutely simple.1

The so-called nervus probandi of this argument lies in
the proposition : that many representations must be con
tained in the absolute unity of the thinking subject, to
make up one thought. But this proposition no one can
prove from concepts. For how could he even commence
his argument ? The proposition : a thought can only be
the effect of the absolute unity of the thinking being —
cannot be treated analytically. For the unity of a thought

1 It is very easy to give this proof in the usual scholastic form. But
it is sufficient for my purpose to present its ground of proof though
merely in a popular form.

230-231] PARALOGISMS OF RATIONAL PSYCHOLOGY 193

which consists of many representations is collective, and, as
far as pure concepts go, might just as well refer to the
collective unity of the co-operating substances (like the
motion of the body being the composite motion of its
parts), as to the absolute unity of the subject. Proceeding
then according to the rule of identity, we cannot see the
necessity of presupposing a simple substance to account
for a composite thought. But that this proposition should
be recognised synthetically and perfectly a priori from pure
concepts, no one will venture to assert, who understands
the basis of the possibility of synthetical a priori judgments,
as already set forth.

Now it is equally impossible to deduce from experience
this necessary unity of the subject, as the condition of the
possibility of each single thought. For experience could
give no necessity, and besides the concept of absolute unity
is far beyond its sphere. Whence then do we [231] get
this proposition, on which the whole psychological syllogism
rests ?

It is plain that, if we wish to represent a thinking being,
we must put ourselves in its place, and so supply our own
subject to the object which we wish to obtain (which is not
the case in any other sort of investigation), and that we
only demand the absolute unity of the subject, because
otherwise we could not say : I think (the manifold of the
representation). For, although the sum of the thought
might be divided and distributed among many subjects, yet
the subjective Ego cannot be divided or distributed, and
this we certainly presuppose in all thinking.

Here, then, as in the previous paralogism, the formal
proposition of apperception, / think, is also the whole basis
upon which rational psychology ventures to extend her
cognitions — a proposition which is not experience, but

I94

APPENDIX C [231-232

merely the form of apperception, belonging to, and pre
ceding, every experience. But with reference to possible
cognition, this must be regarded merely as a subjective
condition, which we have no right to exalt to a condition of
the possibility of objects, that is, to a concept of a thinking
being in general, [merely] because we cannot represent
such a being to ourselves, without putting ourselves with
the formula of our consciousness in the place of every
other intelligent being.

The simplicity of myself (as a soul) is not actually in
ferred from the proposition, I think ; for it already exists
in every thought. The proposition, / am simple, must be
regarded as an immediate expression of apperception, just
as the supposed Cartesian conclusion, cogito ergo sum, is
really tautological, as cogito ( = sum cogitans) expressly asserts
existence. / am [a] simple [being] [232] means nothing
but this — that the representation / does not contain the
least multiplicity, and that it is an absolute (although
merely logical) unity.

Consequently, this celebrated psychological demonstra
tion is merely based upon the indivisible unity of a repre
sentation which only directs the verb \cogitare\ to refer to
a person. But it is plain that the subject of inherence is
only indicated as transcendental by the Ego attached to
the thought, without noting in the least any of its properties,
and without knowing or cognising anything at all about it.
It means something in general (a transcendental subject),
the representation of which must indeed be simple, for the
obvious reason that nothing at all is determined in it, since
we- cannot represent a thing more simply than by the
notion of a mere something. But the fact of the simplicity
of the representation of a subject is not, for that reason, a
cognition of the simplicity of the subject itself; total

232-233] PARALOGISMS OF RATIONAL PSYCHOLOGY 195

abstraction being made from its properties, when it is
merely indicated by the perfectly contentless expression
Ego (which I can apply to every thinking subject).

So much is certain, that I represent to myself by Ego
always an absolute, though only a logical, unity of the
subject (Simplicity), but do not cognise through it the
actual simplicity of my subject. As the proposition, I am.
substance, means nothing but the pure Category, of which
I can make no concrete use (empirically), so I may also
be allowed to say, I am a simple substance, that is, one
whose representation never contains a synthesis of multi
plicity ; but this concept, or even this proposition, does not
give us the least information with regard to myself as an
object of experience, because the concept of substance
itself is only used as a function of [233] synthesis, without
being based on intuition, that is, without any object; so
that it only applies to the condition of our knowledge,
not to any object which we could name. Let us make
an experiment with regard to the supposed use of this
proposition.

Every one must confess that the assertion of the simple
nature of the soul is merely of value so far as I am able
by it to separate this subject from all matter, and con
sequently exempt it from decay, to which matter is always
liable. It is for this use that the above proposition is
specially intended, and it is therefore often thus expressed :
The soul is not corporeal. Now if I can show that, even
conceding to this cardinal proposition of rational psychology
all objective validity (that all which thinks is simple sub
stance), in the pure meaning of a mere judgment of the
Reason (from pure Categories) — even conceding this, I say
— not the least use can be made of it with reference to its
dissimilarity or relation to matter, then I may fairly claim

>96 APPENDIX C [233-234

to have relegated this pretended philosophical truth into
the region of pure Ideas, which are wanting in reality when
objectively used.

We have proved irrefragably in our transcendental
Aesthetic that bodies are mere phenomena of our external
sense, and not things in themselves. In accordance with
this we may say justly, that our thinking subject is not
corporeal, viz. that as it is represented to us as an object
of the internal sense, it cannot, so far as it thinks, be an
object of the external senses, or a phenomenon in space.
This is equivalent to saying : Thinking beings, as such, can
never be represented to us among external intuitions ; or,
we cannot intuite their thoughts, consciousness, desires,
etc. externally; for all these must [234] come before the
internal sense. This argument indeed appears to be also
the natural and popular one, which seems to have satisfied
even the most ordinary understandings, so that from very
early times they began to consider souls as totally distinct
from bodies.

Now extension, incompressibility, connexion, and motion
— in short, all that our external senses only can give us —
are not, and indeed do not contain, thought, feeling, desire,
or resolve, which are not at all objects of external intuition.
Nevertheless, that something which lies at the basis of
external phenomena — which so affects our sense as to give
it the representations of space, matter, form, etc. — that
something, I say, considered as a noumenon (or perhaps
better as a transcendental object), might also at the same
time be the subject of thoughts, although we may not be
able to obtain any intuition of mental states (but only of
space and its determinations), through the means by which
our external sense is affected. But this something is not
extended, impenetrable, or composite, because all these

234-235] PARALOGISMS OF RATIONAL PSYCHOLOGY 197

predicates only concern sensibility and its intuition, so far
as we are affected by that sort of objects (otherwise un-
unknown to us). Yet these expressions by no means
declare to us what sort of an object it is, but only this,
that the predicates of external phenomena cannot be ap
plied to it, considered as an object in itself, and without
reference to external senses. But the predicates of the
internal sense — representation and thinking — do not con
tradict it. Consequently, even admitting the simplicity
of its nature, the human soul is not at all proved to
be distinct from matter, as regards their respective sub
strata^ when considered (as it should be) merely as a
phenomenon.

If matter were a thing per se, it would, as a composite
[235] being, be altogether different from the soul, as a
simple being. But it is only an external phenomenon, of
which the substratum is not cognised by any producible
predicates. I might, then, be quite justified in assuming
of this substratum that it was in itself simple, although in
the way which it affects our senses it produces in us the
intuition of extension, and, along with it, of composition.
It might follow that this substance, to which extension is
added by reference to our external sense, is accompanied
by thoughts in itself, which through its own peculiar in
ternal sense can be represented with consciousness. In
this way the very same thing which in one relation is called
corporeal, is at the same time in another called a thinking
being, whose thoughts indeed we cannot intuite, but only
their evidences, in phenomena. We should thus get rid
of the expression, that souls only (as being a peculiar sort
of substances) think ; we should rather use the ordinary
phrase, that men think ; that is to say, that the very same
thing which is extended as an external phenomenon, is

i98 APPENDIX C [235-236

internally (in itself) a subject not composite, but simple
and thinking.

But, without admitting such hypotheses, we may observe
in general, that if I mean by soul a ^thinking being per se, the
very question is improper, if we mean to ask whether it is
of the same kind, or not, as matter (which is not a thing
per se, but only a sort of representation in us) ; for it is
self-evident that a thing per se must be of a different nature
from the determinations which merely constitute its states.1

But, if we compare the thinking Ego, not with matter,
but with the intelligible something at the basis of the [236]
external phenomena, which we call matter, as we know
nothing of this latter, we cannot assert that the soul differs
from it in any way internally.2

Accordingly, simple consciousness is not a cognition
of the simple nature of our subject, so far as it is to
be distinguished as such from matter as a composite
existence.

But if this concept of simplicity is useless in the only
case where it could be of service (that is, to determine the
peculiar and distinguishing feature of our subject, when I
compare myself with the objects of external experience),
we may fairly despair of ever knowing that /, the soul (a
name for the transcendental object of the internal sense),
am simple. This expression has no application extending

1 Cf. Fischer's Commentary, p. 56, note.

2 The tone of the whole preceding passage corroborates the view
I have taken of the intelligible and empirical characters, and shows
that Kant (at least in his opinions] seems to have ascribed far more
certainty and actuality to the noumenon of internal, than to that of ex
ternal phenomena. At the same time, he never asserts this (because
indemonstrable) ; it is also remarkable that, though he contemplates
the possibility of noumenal monism, he never suggests the possibility
of noumenal nihilism. M.

236-237] PARALOGISMS OF RATIONAL PSYCHOLOGY 199

to actual objects, and cannot possibly, therefore, enlarge our
knowledge.

If these remarks are true, the whole of rational psycho
logy falls to the ground with its principal support ; and we
can as little here as elsewhere hope to extend our informa
tion by pure concepts (still less by consciousness, the mere
subjective form of all our concepts). More especially, the
fundamental notion of a simple nature is such that it
cannot be found in any experience at all ; so that there
is no way of reaching it as an objectively valid concept.

[237] THE THIRD PARALOGISM, OF PERSONALITY

That which is conscious of its own numerical identity at
different times is, so far, a Person.

Now, the soul has this consciousness.
Therefore, it is a Person.

KRITIK OF THE THIRD PARALOGISM OF TRANSCEND
ENTAL PSYCHOLOGY

If I desire to cognise the numerical identity of an exter
nal object by experience, I pay attention to the permanent
[part] of the phenomenon, to which, as subject, all the rest
refers as determination, and remark the identity of the
former in time, while the latter changes. But I am an
object of the internal sense, and all time is merely the
form of the internal sense. Consequently, I refer my
successive modifications, one and all, to the numerically
identical self in all time, that is, in the form of the internal
intuition of myself. Upon this ground the personality of
the soul should be regarded, not as an inference, but as a
perfectly identical assertion of self-consciousness in time ;
and this, too, is the reason why it is valid a priori. For it
says nothing but this : In all the time in which I am con-

200 APPENDIX C [237-239

scious of myself, I am conscious of this time, belonging to
the unity of myself; and it is indifferent whether I say, The
whole of time is in me, who am an individual unity ; or, I
am, with my numerical identity, present in all this time.

Personal identity, then, must be always found in my [238]
own consciousness. But, if I consider myself from the point of
view of another person (as an object of his external intuition),
this observer external to me first of all considers me in time ,
for [though] in [my internal] apperception time is properly
only represented in mel He will, consequently, not con
clude the objective permanence of myself from the Ego,
which accompanies all representations at all times in my con
sciousness, and indeed with perfect identity, even though he
concedes its presence. For, as the time in which the
observer places me is not that which is met with in my sensi
bility, but in his, the identity which is necessarily bound
up with my consciousness is not bound up with his, that
is, with an external intuition of my subject.

[239] The identity, then, of the consciousness of myself at
different times is only a formal condition of my thoughts

1 Kant's argument appears to be as follows : When I regard my own
internal phenomena, I find them to be all subject to the condition of
time ; but this time, again (and the phenomena in it), I perceive always
as in me, as a form of my internal sensibility ; hence, in [internal]
apperception self is the highest condition, to which time is subject.
For this reason the identity of self has been regarded as the necessary
condition of my existence in time. This is true subjectively (in apper
ception), but not so objectively, or absolutely ; for, suppose another man
perceives me, he perceives me through his external sense, and I am
[also] to him in time. But, though he readily admits and believes in
my consciousness being accompanied with a full consciousness of identity,
this identity is not to him the condition of the time in which he places
me. He places me in time, instead of placing time in me. And the
feeling of identity which he allows in me is to him no proof that myself
is objectively permanent ; for it is not necessarily implied by the time in
which he places me. M.

239-240] PARALOGISMS OF RATIONAL PSYCHOLOGY 201

and their connexion, and does not demonstrate the
numerical identity of my subject, in which, notwithstanding
the logical identity of the Ego, such a change might have
taken place as to preclude its [numerical] identity. We
might nevertheless always attribute to it that Ego, which never
varies in name, and which in every different state, even were
the subject changed, could yet always preserve the thought
of the previous subject, and hand it over to the succeeding.1
Although the proposition of some ancient schools — that
everything is in a flux, and nothing permanent — cannot
stand if we assume substances, it is not refuted by the unity
of self-consciousness ; for we ourselves cannot decide from
our own consciousness whether we, as souls, are permanent or
not, because we only consider that to belong to our identical
selves, of which we [240] are conscious ; and so, of course, we
judge necessarily that we are the very same in the whole
time of which we are conscious. But from the point of
view of a stranger we cannot hold this to be a valid
inference ; because, as we meet in the soul no permanent
phenomenon except the representation self, which accom
panies and connects all the rest, we can never ascertain
whether this Ego (a mere thought) is not subject to the same
flux as the remaining thoughts which are connected by it.

I An elastic ball which strikes full upon a similar one imparts to it
all its motion, or all its state (if we merely regard places in space).
Now, let us assume substances after the analogy of such bodies, where
each [reading je\ imparts representations to the next, along with a con
sciousness of them. We might thus conceive a whole series of them,
the first of which imparted its state, and the consciousness thereof, to
the second ; this again its own state, along with that of the first, to
the third ; this again its own and the states of all the previous ones, etc.
In such a case the last substance would be conscious of all the states
of the previously changed substances as its own, since those states
were transferred to it along with the consciousness of them ; never
theless, it would not have been the very same person in all these states,

II P

202

APPENDIX C [240-241

But it is remarkable that the personality, and the perma
nence which it presupposes — that is, the substantiality of
the soul — must now be proved first ; for, could we pre
suppose it, there would follow, not indeed the permanence
of consciousness, but the possibility of a lasting conscious
ness in a permanent subject; and this is sufficient for
personality, which need not itself cease, even though its
action be interrupted for a time. But this permanence is
not given us at all before the numerical identity of our
selves, which we infer from the identity of apperception, but
is rather inferred from that identity (and after this, to make
the argument valid, should follow the concept of substance,
which is the only one of them that is of empirical use).
Now, as this identity of person by no means follows from
the identity of the Ego in all the time in which I cognise
myself — so we already found that the substantiality of the
soul could not be based upon it.

Nevertheless, the concept of personality (as well as that
of substance and simplicity) may remain, so far as it is
transcendental, and means a unity of the subject other
wise unknown to us, but in whose states there is thorough
going connexion through apperception. And [241] so far
indeed this concept is both necessary and sufficient for all
practical uses ; but we can never depend upon it to extend
our self-cognition through pure^Reason (which mirrors to us
a permanence of the subject), from the mere concept of the
identical self, as this concept always revolves about it itself,
and does not assist in solving a single question which aims
at synthetical cognition. What sort of thing per se (tran
scendental object) matter may be is wholly unknown to
us ; nevertheless, its permanence as phenomenon may be
observed when it is represented as something external.
But when I wish to observe the mere Ego in the alteration

241-242] PARALOGISMS OF RATIONAL PSYCHOLOGY 203

of all representations — as I have no other correlation for
my comparisons except the same identical self with the
universal conditions of my consciousness — I can only give
tautological answers to all questions by supplying my concept,
and its unity, to those properties which I possess as an
object, and so by assuming what was under investigation.

THE FOURTH PARALOGISM, OF IDEALITY (OF EXTERNAL
RELATIONS) *

Whatsoever can only be inferred to exist, as the cause
of given perceptions, has only a doubtful [problematical]
existence.

Now, all external phenomena are of such a kind that
their present existence cannot be perceived immediately, but
we infer them to exist as the cause of given perceptions.

[242] Consequently, the existence of all the objects of
the external senses is doubtful. This uncertainty I call the
ideality of external phenomena; and the doctrine which
holds this ideality is Idealism, in contrast to which the asser
tion of a possible certainty of objects of the external senses
is called Dualism.

KRITIK OF THE FOURTH PARALOGISM OF TRANSCEND
ENTAL PSYCHOLOGY

We shall first analyse the premises. We may justly assert
that only what is within us can be immediately perceived,
and that my own existence alone is the object of a bare
perception. Consequently, the existence of an actual object

1 This paralogism does not appear in the Second Edition probably
because the ' Refutation ' had already settled the question as to the
relative dignity and priority of our internal and external experi
ence. M.

204

APPENDIX C [242-243

without me (if this word be used in an intellectual sense) is
never given immediately in perception, but can only be added
in thought to the perception (which is a modification of our
internal sense) as its external cause, and so inferred from it.
Consequently, Descartes justly restricted all perception in the
strictest sense to the proposition, I (as a thinking being)
exist \ for it is clear that, as the external is not in me, it can
not possibly be found in my apperception, or in any percep
tion, which is properly only a determination of apperception.

I cannot, then, properly perceive external things, but
only infer their existence from my internal perception by
regarding it as an effect, of which something external is the
proximate cause. But the inference from a given effect to
a determinate cause is always [243] precarious, because the
effect may have been produced by more than one cause.

Consequently, with regard to the relation of perception
to its cause, it must ever remain doubtful whether such
cause be internal or external — whether all so-called external
perceptions are not a mere play of our internal sense, or
whether they indeed refer to actual external objects as their
causes. At all events, the existence of the latter is only an
inference, and runs the risk of all inferences ; while, on the
contrary, the object of the internal sense (I myself, with
all my representations) is perceived immediately, and its
existence can be in no doubt.1

By idealist^ then, we must not understand the man who
denies the existence of external objects, but only one who
will not concede that it is known by immediate perception,

1 This is the very question discussed in the much abused Refutation
of Idealism, in the Second Edition. The definition of idealism
which immediately follows above, shows how strictly Kant confined
both this and the corresponding refutation in the later Editions to
Descartes, and did not consider Berkeley, as Fischer and other Germans
allege. M.

243-244! PARALOGISMS OF RATIONAL PSYCHOLOGY 205

and who concludes, accordingly, that we can never be
absolutely certain of their actuality by any possible experience.

Now, before I propound our paralogism in its delusive
form, I must observe that we must necessarily distinguish
two sorts of idealism — transcendental and empirical. By
the transcendental idealism of all phenomena, I mean the
doctrine according to which we regard them all as mere re
presentations, not as things perse, and according to which space
and time are merely [244] sensuous forms of our intuition,
not determinations given per se, or conditions of objects as
things per se. Opposed to this doctrine is transcendental
Realism, which regards space and tjme as something given
per se (independent of our sensibility). The transcendental
Realist, then, represents to himself external phenomena (if
we allow their actuality) as things per se, which exist in
dependent of us and our sensibility, and should therefore
also be without us according to pure concepts. This
transcendental Realist is the proper man to turn empirical
idealist ; and, after he has falsely assumed of objects of our
senses, that if they are to be external, they must possess
existence in themselves apart from the senses, he then finds
all the representations of our senses insufficient to guarantee
the actuality of these representations.1

The transcendental idealist, on the contrary, can be an
empirical Realist, or, as he is called, a Dualist ; that is, he
can concede the existence of matter without going beyond
mere self-consciousness, or assuming anything beyond the
certainty of the representations in me, or the cogito ergo sum.
For since he considers this matter, and even its internal
possibility,2 to be nothing but phenomenon, which apart
from our sensibility is nothing at all, he only considers it as
a kind of representations (intuition) which are called ex-
1 Cf. Fischer's Commentary^ p. 189. 2 Cf. vol. i. p. 268, note.

206 APPENDIX C [244-245

ternal, not as if they referred to objects external in themselves?-
but because [245] they refer perceptions to space, in which all
things are reciprocally external, while space itself is within us.
We have declared ourselves in favour of this tran
scendental idealism throughout. Accepting our doctrine, all
difficulty of admitting the existence of matter on the
testimony of our mere consciousness vanishes, as well as of
declaring it so proved, just as the existence of myself as a
thinking being is so proved. For I am surely conscious of
my representations ; these then, and I who have them, exist.
But external objects (bodies) are mere phenomena, and
nothing at all but a species of my representations, the
objects of which only exist through these representations,
and apart from them are nothing. External things, there
fore, exist just as much as I myself do, and both upon the
immediate evidence of my self- consciousness ; with this
difference, that the representation of myself as a thinking
subject is referred only to the internal sense, but the
representations which denote extended existences are
referred also to the external sense. With regard to the
actuality of external objects, I have just as little need of
inference as with regard to the actuality of the object of my
internal sense (my thoughts) ; for they are both nothing
but representations, the immediate perception (conscious
ness) of which is likewise a sufficient proof of their
actuality.2

1 Kant here asserts the doctrine of transcendental idealism to be this :
that external phenomena do not refer to objects in themselves external
to us. From this Kuno Fischer infers (loc. cit.} that Kant denied any
noumenon to exist as the (hidden) basis of external phenomena. This
inference is unwarranted ; for, in Kantian language, neither could the
noumenon be called an object, nor external (in this sense) ; so that the
present argument does not touch that question. Cf. below, p. 208. M.

2 This is the precise doctrine of the refutation of idealism in the

246-247] PARALOGISMS OF RATIONAL PSYCHOLOGY 207

[246] The transcendental idealist is then an empirical real
ist, and allows matter, as phenomenon, an actuality which
need not be inferred, but is immediately perceived.
Transcendental Realism, on the other hand, necessarily
becomes perplexed, and is forced to make way for empirical
idealism, because it regards the objects of external senses as
something distinct from the senses themselves, and mere
phenomena as independent beings existing without us.
However perfectly we may be conscious of our representa
tion of these things, this is far from proving that, if the
representation exists, its corresponding object must also
exist ; while on our system, these external things (or matter,
in all its forms and changes) are nothing but mere
phenomena, or representations in us, of whose actuality we
are immediately conscious.

As all the psychologists who subscribe to empirical
idealism are, as far as I know, also transcendental realists,
they have been perfectly consistent in attaching great
weight to empirical idealism, as one of those problems which
human reason can hardly solve. For, most assuredly,
if we regard external phenomena as representations which
are produced in us by their object — a thing per se existing
without us — then how can its existence be known, except
by inferring the cause [247] from the effect, in which case it
must always remain doubtful whether this latter be within or
without us. Now it may indeed be conceded that some
thing is possibly the cause of our external intuitions, which
is without us in the transcendental sense ; but this is not

Second Edition (Kritik, p. 167). The concluding limitation is also
there distinctly implied in the statement (p. 166) that the Aesthetic has
removed all possibility of making space a property of things per se. ' For
in such case both it and they become perfectly impossible and absurd.'
Yet the argument which follows has been interpreted by all Kant's
critics as implying this absurdity ! M.

2o8 APPENDIX C [247-248

the object which we understand by the representations of
matter and corporeal things ; l for these are mere phe
nomena — mere species of representation — which are in all
cases only within us ; and their actuality rests upon
immediate consciousness, just as the consciousness of my
thoughts does. The transcendental object, as well of
internal as of external intuition, is to us equally unknown.
Not this however, but the empirical object, is in question,
which is called external if it is in space — internal, if it is
represented in time-relations only ; but space and time are
both only to be found within us.

But, as the expression without us is unavoidably
ambiguous (meaning either that which exists as a thing per
set distinct from us, or merely that which belongs to external
phenomena), in order to secure to this concept the latter
meaning — being that in which the psychological question
about the reality of our external intuition [248] arises — we
shall distinguish empirically external objects from those
possibly so called in a transcendental sense, by denominating
them simply things which can be perceived in space.

Space and Time are indeed representations a priori
present to us as forms of our sensuous intuition, before any
actual object has determined us by sensation to represent
it under these sensuous relations. But this material or real
something, which is to be intuited in space, necessarily

1 The theory which Kant is here opposing asserts that there are
external objects, corresponding to, and resembling in some way, our
perceptions. He does not here desire to refute his own doctrine, that
there are possibly noumena at the basis of phenomena, but to prove that
these noumena cannot be objects in space. If this be the meaning of
his argument (which is somewhat obscurely expressed), Kuno Fischer is
just as much mistaken in asserting that Kant here denies any special
noumena for external phenomena, as he is in interpreting the
' Refutation of idealism ' to be the assertion of noumena in space. M.

248-249] PARALOGISMS OF RATIONAL PSYCHOLOGY 209

presupposes perception,1 and cannot be in any way imagined
or produced independently of this perception, which
announces the actuality of something in space. It is then
sensation which indicates actuality in space and time, as
soon as this sensation has been referred to either species of
sensuous intuition. Sensation, when applied to an object
in general, without determining it, is called perception.
This sensation being given, by means of its manifoldness
we can imagine various objects which, beyond imagination,
have no empirical place in space or time. Whatever
examples then of sensations we take, whether pleasure or
pain, or external ones like colour and heat, this remains
quite certain, that perception is that through which the ma
terial must be given, in order to supply objects to sensuous
intuition. This perception then (to keep to external
intuitions at present), represents something actual in space.
For in the first place, perception is the repre- [249] sentation
actuality, as space is of the mere possibility, of simultaneous
existence. Secondly, this actuality is represented for the
external sense, that is, in space. Thirdly, space itself is
nothing but mere representation. Nothing then can be
considered as actual in space, except that which is repre
sented in it;2 and, vice versa, what is given in space (or

1 Here is an assertion expressly contradicting Kuno Fischer's doctrine
that the external thing is (in itself) nothing but our sensation. It pre
supposes, as a necessary condition of being perceived, our faculty of
perception, but cannot be asserted identical with it. The sequel is
still more explicit. M. _

2 This paradoxical, but true, proposition should be carefully noted —
viz., nothing is in space except what is represented in it. For space
itself is nothing but representations ; consequently, whatsoever is in
space must be contained in the representation, and there is nothing at
all in space except so far as it is actually represented in it. The
assertion, no doubt, sounds strange — that a thing can only exist in its
own representation ; but the absurdity is here obviated since we are

210

APPENDIX C [249-250

represented through perception) is also actual in it; for,
were it not actual in it — that is, were it not given im
mediately by empirical intuition — it could not be invented,
because the real element in intuitions cannot at all be
obtained by a priori thinking.

All external perception, then, proves immediately that
there is something actual in space, or rather it is itself this
very actuality, and so far empirical realism is beyond
question ; that is to say, there corresponds to external in
tuitions something actual in space. It is true that space
itself, with all its phenomena, only exists within me ; but
nevertheless in this space reality, or the material of all
objects of external intuition, is given actually and inde
pendently of all invention. It is also impossible that in
this space anything without us (in the transcendental sense)
should be given, because space itself, apart from our
sensibility, is nothing. The most extreme idealist cannot,
then, call upon us to prove that the [250] object without
us (in the strict sense) corresponds to our perception. For
if such a thing did exist, it could not be represented or in
tuited as without us, since this would presuppose space ;
and actuality in space, as of a mere representation, is
nothing but the perception itself. That which is real in
external phenomena is only actual in perception, nor can it
be actual in any other sense.

From perception we can produce objects, either by the
play of fancy, or through experience. And so, no doubt,
illusive representations may arise, not corresponding with
objects, and we must ascribe this illusion either to images
of the fancy (dreams), or to a mistake of the faculty of
judgment (in the case of the so-called deceptions of the

concerned not with things per se, but only with phenomena — sc.
representations.

250-251] PARALOGISMS OF RATIONAL PSYCHOLOGY 211

senses). To avoid these illusions, we [proceed according
to the following rule : that which is connected with a percep
tion according to empirical laws is actual}- But this illusion,
as well as the caution against it, affects idealism, as well as
dualism, since it only concerns the form of experience. In
order to refute empirical idealism, which falsely questions
the objective reality of external perceptions, it is enough
that external perception should immediately prove an
actuality in space, which space, although it be the mere
form of representations, nevertheless possesses objective
reality with regard to all external phenomena, which are
nothing but representations. It is enough to show that
without perception even invention and dreaming would be
impossible; so that our external senses, as far as the [251]
data for experience are concerned, must have their actual
corresponding object in space.

The man who denies the existence of matter would be
the dogmatical idealist ; he who doubts it, because it cannot
be proved, would be the sceptical idealist The former
theory results from believing that there are contradictions
in the possibility of there being matter at all — a question
with which we are not yet concerned. The following
section, on dialectical syllogisms, which portrays the reason
in internal conflict about the concepts which it has formed
as regards the possibility of what belongs to connected ex
perience, will help to solve that difficulty [of dogmatic
idealism]. But the sceptical idealist, who only attacks the
grounds of our assertion, and declares our conviction of the
existence of matter to be insufficient — which we believe
we can found on immediate perception — such a man is a
benefactor to human reason, since he compels us, even in

1 The whole discussion turns on this, the second postulate of empiri
cal thought. Cf. vol. i. p. 193. B.

212 APPENDIX C [251-252

the most trifling steps of ordinary experience, to keep wide
awake, and not to annex as lawful property anything that
we have obtained by foul means. The use of these ideal
istic objections is now quite clear. They force us, if we
wish to avoid confusion in our most ordinary assertions, to
consider all perceptions, whether internal or external, as
merely the consciousness of what belongs to our sensi
bility ; and their external objects not as things per se, but
only representations, of which we are as immediately con
scious as of any other representations. They are only called
external because they belong to that sense which we call
the external sense, of which the intuition is space ; and this
space is nothing but an internal species of representation,
in which certain perceptions are connected with one another.
[252] Supposing we allowed external objects to be things
per se, it would be absolutely impossible to comprehend
how we could obtain a knowledge of their actuality without
us, since we rely merely on the representation which is
within us. For, since no one can have a sensation without
himself, but only within, the whole of self-consciousness
gives us nothing but our own determinations. Con
sequently sceptical idealism compels us to take refuge in
the only course still open, that is, in the ideality of all
phenomena ; and this we expounded in the transcendental
Aesthetic, independent of the consequences, which we
could not have then foreseen. If it be now asked, whether
dualism must consequently follow in psychology, we answer,
certainly, but only in the empirical sense ; that is to say, in
the connected whole of experience, matter, as substance in
phenomena, is actually given to the external sense, and the
thinking Ego is also given to the internal sense, as substance
in the phenomenon ; and in both cases phenomena must
be connected according to the rules which this Category

252-253] PARALOGISMS OF RATIONAL PSYCHOLOGY 213

[of substance] introduces into the connexion of our external
as well as internal representations. But if we desire to
widen, as is usual, the notion of dualism, and take it in its
transcendental sense, then neither this doctrine, nor Pneu-
matisin nor Materialism, which oppose it from different
sides, have the least basis. We should then miss the proper
determination of our concepts, and consider a difference in
the mode of representation of objects (which remain un
known to us, as to what they are in themselves) to be a
difference in these things themselves. /, who am re
presented through the internal sense as in time, and objects
without me, are indeed phenomena totally distinct in kind,
but need not therefore be thought as distinct [253] things.
The transcendental object, which lies at the basis of internal
intuition as well as of external phenomena, is neither matter,
nor a thinking being per se, but a basis of phenomena un
known to us, and these give us the empirical concept as
well of the first as of the second.

If then, as the present Kritik plainly compels us, we
keep faithfully to the rule we have established, not to push
our questions any further than possible experience has
supplied us with objects for them, it will never even come
into our heads to make investigations about the objects of
our senses as to what they may be in themselves, out of
relation to our senses. But if the psychologist takes phe
nomena for things in themselves, he may, as a materialist,
accept for his doctrine nothing but matter ; or, as a spirit
ualist, nothing but thinking beings (according to the form
of our internal sense) ; or even, as a dualist, he may regard
both to be things existing per se. In any case his miscon
ception will condemn him to be ever speculating how that
is to exist per se which is no thing per se, but only the
phenomenon of a thing in general.

2i4 APPENDIX C [253-254

REFLECTION CONCERNING THE WHOLE OF PURE PSYCHO
LOGY, AS AN APPENDIX TO THESE PARALOGISMS

If we contrast the doctrine of the soul [psychology], as the
physiology of the internal sense, with the science of bodies —
as the physiology of the objects of the external senses — we
shall find (in addition to the fact that in both we know a
great deal empirically) this remarkable difference, that in
the latter science much can be cognised a \2^^\ priori from
the mere concept of an extended incompressible being ;
whereas in the former, from the concept of a thinking
being, nothing can be cognised synthetically a priori.
Because although both are phenomena, yet the phenomenon
presented to the external sense has something permanent 1
or fixed, which gives a substratum lying at the basis of
changeable determinations, and so gives us a synthetical
concept, namely, that of space and a phenomenon in it.
Time, on the contrary, which is the only form of our in
ternal intuition, has nothing permanent in it; so that it
only lets us know the change of determinations, not the
determinable object. For in that which we call the soul
everything is in a continuous flux, and nothing is permanent
except (if you will have it so) the Ego, which is perfectly
simple, merely because this representation has no content
or multiplicity ; for which reason it seems to represent or,
I should rather say, indicate a simple object. In order to
produce a pure rational cognition of the nature of a think
ing being in general, this Ego should be an intuition, which,
being presupposed in all thinking (antecedent to any experi-

1 This important passage again anticipates (almost verbally) the re
futation of idealism of the Second Edition. It shows the superior
dignity of external experience, as contrasted with internal, in affording
us data for science. M.

254-255] PARALOGISMS OF RATIONAL PSYCHOLOGY 215

ence), should give us synthetical a priori propositions.
But this Ego is just as little an intuition as it is a concept
of any object, being merely the form of consciousness which
can accompany both kinds of representations, and raise
them to cognitions, so far as something else is given in in
tuition which supplies the material for the representation of
an object. Thus all rational psy- [255] chology falls to the
ground, being a science surpassing all the powers of the
human reason ; and there remains nothing for us except to
study our souls according to the clue given by experience,
and to keep within the limits of questions not exceeding
the content which can possibly be given by internal experi
ence.

But though this science gives us no ampliative know
ledge, but is composed (when it attempts to do so) of
nothing but paralogisms, yet we cannot deny it an im
portant negative use, if we consider it as nothing but a
critical treatment of our dialectical syllogisms, and indeed
of the ordinary natural reason.

Why do we require a psychology founded upon pure
principles of the Reason only? Without doubt, for the
particular object of securing our thinking self from the
danger of Materialism. This is done by the rational
notion of our thinking self, which we have set forth ; for,
instead of there being any danger that if matter were taken
away, all thinking — and even the existence of thinking
beings — would consequently vanish, it is rather clearly
shown that, if I take away the thinking subject, the whole
world of matter must vanish, being only what appears in the
sensibility of our subject, as a species of its representations.

Having proved this, I am of course not in the least
better able to know this thinking self by its properties.
Nay, I cannot even prove its existence to be independent

216 APPENDIX C [255-256

of the transcendental substratum (whatever it is) of external
phenomena; for both are to me unknown. Yet, as it is
possible for me to find a reason in other than merely specu
lative grounds for hoping that my thinking nature will
remain permanent in the midst of all possible changes of
state — as this is possible, though I [256] openly confess my
own ignorance — an important point is gained, since I am able
to repel the dogmatical attacks of speculative opponents, and
show them that they can never know more of the nature of
my thinking subject, to enable them to deny the possibility
of my hopes, than I can, to enable me to maintain them.

On this transcendental illusion in our psychological
concepts are based three additional dialectical questions,
which form the proper object of rational psychology, and
which can only be decided by the foregoing investigations.
These are : — (a) The possibility of the community of the
soul and an organic body, i.e. the animality and condition
of the soul in this life ; (/3) The commencement of this
community, i.e. the state of the soul at and before birth ;
(y) The end of this community, i.e. the state of the soul
at and after death (the question of immortality).

Now I assert that all the difficulties with which these
questions are supposed to be beset, and with which, used
as dogmatical objections, men pretend to a deeper insight
into the nature of things than can be obtained by plain
common sense — I say that all such difficulties are based on
a mere delusion, by which what only exists in our thoughts
is hypostatised, and, without its quality being changed,
assumed to be an actual object without the thinking subject :
for example, extension, which is nothing but a phenomenon,
is taken for a property of external things existing apart from
our sensibility ; and motion is regarded as their action, tak
ing place actually in itself, even apart from our senses. For

256-257] PARALOGISMS OF' RATIONAL PSYCHOLOGY 217

matter, the community of which with the soul raises such
difficulties, is nothing but a mere form, or a certain species,
of the representation of an unknown object through that
intui-[257] tion which is called the external sense. There
may indeed, then, be something without us to which this
phenomenon, which we call matter, corresponds; but in
the same quality as phenomenon it is not without us [in
the transcendental sense], but merely a thought within us,
although this thought (through the sense just mentioned)
represents it as to be found without us.1 Matter then
signifies, not a species of substance, thus distinct and
heterogeneous from the object of the internal sense (soul),
but only the difference in kind of the phenomena of objects
(in themselves unknown to us), whose representations we call
external, as compared with those ascribed to the internal
sense, even though the former belong just as much to the
thinking subject as do all the rest of our thoughts. They
have, however, this illusion about them, that as they re
present objects in space, they as it were sever themselves
from the soul, and seem to exist separate from it, although
space itself, in which they are intuited, is nothing but a
representation, the object of which, in the same quality,
cannot be met at all without the soul. Accordingly, the
question is no longer about the community of the soul with
other known and heterogeneous substances without us, but
merely concerning the connexion of the representations of
the internal sense with the modifications of our external
sensibility ; and how it is that these are connected together
according to constant laws, so as to form one systematic
experience.

1 Here is a plain assertion of what I before explained, that Kaiit is
refuting, not a thing per se, about which we can assert nothing, but '
such an absurdity as a noumenon in space. M.

II Q

218 APPENDIX C [257-259

As long as we conjoin in experience internal and [258] ex
ternal phenomena as mere representations, we find nothing
absurd or strange in the community of both species of
sense. But as soon as we hypostatise external phenomena,
and consider them no longer as representations, but as
things existing by themselves without us, in the same quality as
they are in us, and refer their activity, which they exhibit as
phenomena in mutual relation, to our thinking subject — if
we do this, the effective causes without us assume a char
acter which will not tally with their effects in us, because
the former refers merely to the external, the latter to the in
ternal, sense ; and, though these are united in one subject,
they are still very different in kind. Here, then, we
have no external effects, except changes of place, and no
forces except tendencies which concern relations in space
as their effects. But within us the effects are thoughts,
among which no relation of place, motion, figure, or any'
space-determination takes place ; and we lose the clue to
the causes altogether in the effects, which they should
manifest in the internal sense. But we ought to remember
that bodies are not objects per se, present to us, but a mere
appearance of nobody-knows-what-sort-of unknown object;
that motion is not the effect of this unknown cause, but
merely the appearance of its influence on our senses ; con
sequently, that both are not anything without us, but mere
representations within us. It follows, that it is not the
motion of matter which produces representations in us, but
that this motion itself (and matter also, which makes itself
cognoscible by this means) is mere representation ; and,
finally, that the whole difficulty we have conjured up
amounts to this : how, and through what cause, the repre
sentations of our sensibility are so related, that those which
we call external intuitions can [259] be represented as

259-260] PARALOGISMS OF RATIONAL PSYCHOLOGY 219

objects without us, according to empirical laws. This
question by no means contains the supposed difficulty of
explaining the origin of the representations of causes which
exist without us, and act in a foreign way — in that we take
the appearances of an unknown cause to be a cause without
us — a proceeding which can breed nothing but confusion.
In those judgments where there occurs a misconception
rooted in long habit, it is not possible to bring the correc
tion [of the error] within our grasp, in the same degree as
in those other cases where no such unavoidable illusion
confuses our concepts. Hence this our emancipation of
the reason from sophistical theories, can hardly as yet have
the clearness which alone produces perfect satisfaction.

I hope to make the matter plainer in the following
way : —

All objections may be divided into dogmatical, critical,
and sceptical. A dogmatical objection is directed against a
proposition ; a critical, against the proof of a proposition.
The former presupposes an insight into the nature of an
object, in order that we may be able to assert the reverse
of what is stated concerning the object ; such a proposition,
then, is itself dogmatical, and professes to know more of
the property in question than its opponent. The critical
objection, as it never touches the truth or falsity of the
proposition, and only attacks the proof, does not require, or
pretend to, a better knowledge of the object than the
opposed assertion ; it only proves the assertion groundless
. — not that it is false. The sceptical objection opposes
mutually the proposition and its contradictory, as objections
of equal value, proposing each in turn as a dogma, and the
other as the objection to it, and so appears to be from
opposite sides dog- [260] matical, in order to destroy com
pletely any judgment about the object. Both the dog-

220

APPENDIX C [260-261

matical and sceptical objections must pretend to so much
insight into their objects as is necessary to assert something
of them affirmatively or negatively. The critical alone
differs from them, in that it overthrows the theory by
showing that something worthless or merely imaginary has
been assumed in its assertions, and by removing this supposed
foundation, without wishing to assert anything concerning
the nature of the object.

Now according to the ordinary notions of our reason as
to the community in which our thinking subject stands
with things without us, we are dogmatical, and regard them
as true objects, existing independent of us, according to a
transcendental dualism, which does not attribute these ex
ternal phenomena, as representations, to the subject, but
transports them, just as we get them from sensuous intuition,
out of ourselves as objects, which this dualism separates
completely from the thinking subject. This subreptio is the
foundation of all theories as to the community between
body and soul ; and the question is never raised whether
the objective reality of phenomena be certainly true : this
is rather assumed as conceded, and fallacious reasonings
started as to its explanation or conception. The three
ordinary systems invented to meet this difficulty, and in
deed the only possible ones, are those of physical influence^
of pre-established harmony, and of supernatural assistance.

The two latter explanations of the community of the
soul with matter are based upon objections to the first
(which is the representation of common sense), namely,
that what appears as matter cannot by immediate influence
be the cause of representations, which are a perfectly [261]
heterogeneous sort of effect. But when men argue in this
way [it is clear that] they cannot unite with the * object of
the external sensibility' the notion of a matter which is

261-262] PARALOGISMS OF RATIONAL PSYCHOLOGY 221

only phenomenon, or in itself mere representation, pro
duced by any sort of external objects ; for if they held this,
they would have said that the representations of external
objects (phenomena) cannot be external causes of pheno
mena in our minds — a senseless objection, for it never
could come into any man's head to consider that what he
had already acknowledged to be mere representation was
an external cause. According to our principles, their theory
must rather attempt to show that the true (transcendental)
object of our external senses cannot be the cause of those
representations (phenomena) which we understand by the
word matter. Now, as no one can pretend with any
reason to know aught of the transcendental cause of the
representations of our external senses, their assertion is
quite groundless. But, if the pretended correctors of the
doctrine of physical influence regard matter as such (after
the usual manner of transcendental dualism) to be a thing
per se (and not the mere phenomenon of an unknown
thing), and direct their objections to prove that such an
external object, which exhibits no other sort of causality
except motions, can never be the efficient cause of repre
sentations, but that a third being must interfere to produce,
if not reciprocal action, at least correspondence or harmony
between both; [if these theorists take this course] then
their refutation of their opponents must begin by assuming
the [same] TT/JWTOV ^evSos [as the theory] of physical in
fluence in their own dualism; and so by their objection
they would not so much refute Natural Influence as refute
their own dualistic assumption. For [262] all difficulties
which beset the connexion of thinking nature with matter
arise, without exception, merely from the insinuation of the
dualistic representation, that matter as such is not pheno
menon, or a mere representation of the mind, to which an

222 APPENDIX C [262-263

unknown object corresponds, but is that object in itself, as
it exists without us, and apart from all sensibility.

There can, then, be no dogmatical objection made to
the usually accepted Physical Influence ; for, if our
opponent assumes that matter and its motion are mere
phenomena, and therefore themselves mere representa
tions, he can only raise this difficulty, that the unknown
object of our sensibility cannot be the cause of represent
ations in us — a thing which he has not the least right
to assert, because nobody can tell of an unknown object
what it can or cannot do. He must, however, after the
proofs given above, necessarily concede this transcend
ental idealism, so far as he does not openly hypostatise
representations, and place them, as true things, without
himself.

But a well-founded critical objection can still be made to
the common doctrine of physical influence. Such a pre
tended community between two kinds of substances — the
thinking and the extended — presupposes a gross dualism,
and makes the latter, which are nothing but mere representa
tions of the thinking subject, into things existing per se.
Physical influence thus misconceived may then be com
pletely overthrown by showing its grounds of proof to be
idle, and surreptitiously obtained.

The notable question concerning the community of
that which thinks and that which is extended — if we
discard all fictions — would simply come to this : How
external intuition, viz. that of space (the occupation of
[263] it, figure and motion) can be at all possible in a
thinking subject 1 But to this question no man can ever
find an answer ; and we can never supply this gap in our
knowledge, but only indicate it by ascribing external
phenomena to a transcendental object (as the cause

263-264] PARALOGISMS OF RATIONAL PSYCHOLOGY 223

of this sort of phenomena), which however we do not
know, and of which we can never obtain any notion.
In all problems which may arise in the field of experi
ence we treat these phenomena as objects per se, without
concerning ourselves about the highest ground [or condi
tion] of their possibility. But, if we transgress this
boundary, the concept of a transcendental object becomes
necessary.

From these considerations about the community be
tween extended and thinking beings there follows, as
an immediate consequence, the settlement of all disputes
or objections which concern the condition of this think
ing nature before the community (this life), or after its
cessation (in death). The opinion that the thinking
subject could think previous to any community with
the body would be thus expressed : that before the com
mencement of this sort of sensibility, by which some
thing appears to us in space, the same transcendental
objects — which in our present condition appear as bodies
— may have been intuited quite differently. The opinion
that the soul, after the cessation of all community with
the corporeal world, can still continue to think, would
announce itself in this form : that when that sort of
sensibility ceases by which transcendental — and now
wholly unknown — objects appear to us, all intuition of them
may not consequently vanish ; and that it is quite possible
for the same unknown objects to continue being [264]
cognised by the subject, though, of course, no longer in the
quality of bodies.1

1 To assert of the writer of the preceding argument that he is an
absolute idealist is surely very strange criticism. It is impossible
to conceive a more distinct and official refusal to accept that extreme
doctrine. M.

224

APPENDIX C [264-265

Now it is true that no one can show the smallest
foundation for such an assertion from speculative prin
ciples, or even explain its possibility, but only presup
pose it ; yet on the other hand no one can oppose it with
any valid dogmatical objection. For, whoever he may
be, he knows no more of the absolute and internal cause
of external or corporeal phenomena than I or anybody
else. He cannot then reasonably pretend to know on
what the actuality of external phenomena depends in the
present state (in life), nor consequently, that the condi
tion of all external intuition, or even that the thinking
subject itself, must cease to exist after this state (in
death).

The whole dispute, then, about the nature of our
thinking being and its connexion with the world of
matter, merely arises from our supplying the gaps in
our knowledge by paralogisms of the Reason, in that we
make our thoughts to be things, and hypostatise them,
whence arises an imaginary science, both as regards its
affirmations and its negations. We either pretend to
know something of objects, of which nobody has the
least notion, or we consider our own representations to
be objects, and so become involved in a perpetual circle
of ambiguities and contradictions. Nothing but the
sobriety of a severe but fair Kritik can free us from this
[265] dogmatical illusion, which enslaves so many of us
in fancied happiness under theories and systems, and can
restrict all our speculative claims to the field of possible
experience — not indeed by ill-natured ridicule of our
many failures, nor by pious laments about the limits
of our reason, but by determining these limits accurately
according to fixed principles. By this means its 'thus
far, and no farther,' is most securely fixed at those

265-266] PARALOGISMS OF RATIONAL PSYCHOLOGY 225

pillars of Hercules which nature herself has set up, in
order to allow the voyage of our reason to extend only
as far as the receding coasts of experience reach — coasts
that we cannot leave without venturing into a boundless
ocean, which, after constant illusions, ultimately compels
us to give up as hopeless all our laborious and tedious
efforts.

We still owe to our reader a distinct and general
explanation of the transcendental and yet natural illusion
in the paralogisms of the pure Reason, as well as a
justification of their systematic arrangement running parallel
to the Categories. This we could not undertake at the
commencement of the section without the danger of be
coming obscure, or awkwardly anticipating ourselves. We
now desire to discharge this obligation.

We can consider all illusion to consist in this — that the
subjective condition of thinking is taken for the cognition
of the object. We have further shown, in the introduction
to the transcendental Dialectic, that pure Reason is
merely concerned with the totality of the synthesis of
the conditions of a given conditioned. [266] Now, as the
dialectical illusion of the pure Reason cannot be an
empirical illusion, occurring with determinate empirical
cognition, it must concern the conditions of thinking gener
ally, and there can be only three cases of dialectical use of
the pure Reason —

1. The synthesis of the conditions of a thought in
general ;

2. The synthesis of the conditions of empirical
thinking ;

3. The synthesis of the conditions of pure thinking.

226 APPENDIX C [266-267

In all these cases the pure Reason merely employs
itself upon the absolute totality of this synthesis ; that is,
upon that condition which is itself unconditioned. On this
division also is founded the threefold transcendental illusion,
which gives rise to the three divisions of the dialectic, and
affords the Idea to just as many apparent sciences arising
out of pure Reason — to transcendental psychology, cos
mology, and theology. We are here only concerned with
the first.

As in the case of thinking in general we abstract from
all relation of our thought to any object (be it of the senses,
or of the pure understanding), the synthesis of the condi
tions of a thought in general (No. i) is not at all objective,
but merely a synthesis of the thought with the subject,
which synthesis is falsely held to be a synthetical representa
tion of an object.

But it follows from this, that the dialectical inference
to the condition of all thinking in general, which is
itself unconditioned, does not make a mistake as to
content (for it abstracts from all content or object), but
that it is merely false as to form, and must be called a
paralogism.

Furthermore, as the condition which accompanies [267]
all thinking is the Ego, in the general proposition, ' I
think,' Reason must be concerned with this condition, so
far as it is itself unconditioned. But this is only the formal
condition or logical unity of every thought, in which I
abstract from all objects, and yet it is represented as an
object which I think, that is, the Ego and its unconditioned
unity.

Suppose any one were to put me the general ques
tion : Of what sort of nature is a thinking being ? I do
not in the least know how to answer the question a priori,

267-268] PARALOGISMS OF RATIONAL PSYCHOLOGY 227

because the answer must be synthetical (for an analytical
answer might, perhaps, explain thinking, but could not
extend our knowledge of that upon which thinking
depends as to its possibility). But for every synthetical
solution intuition is necessary, a point which is wholly
passed over in the vague problem proposed. It is equally
impossible to answer, in all its generality, the question :
Of what nature must a thing capable of motion be ? For
incompressible extension (matter) is not then given
to us. Yet, although I know no answer in general to
that sort of question, it appears to me that I might give
one in the special case of the proposition, ' I think,' which
expresses consciousness. For this Ego is the first
subject — that is, substance — it is simple, etc. But
these must be mere empirical judgments, which, at the
same time, could not contain any such predicates (which
are not empirical), without a general rule to express
the conditions of the possibility of thinking them in
general, and this a priori?- Thus, what I [268] at first
thought so feasible (viz. judgments concerning the nature
of the thinking being, and this from pure concepts),
becomes suspicious, even though I have not yet discovered
my mistake.

But the further investigation into the origin of these
properties, which I attribute to myself, as a thinking being
in general, exposes the error. They are nothing more than
pure Categories, by which I can never think a determined
object, but only the unity of representations, in order to
determine them as an object. Without being founded on
an intuition, the Category alone can never provide me with
a concept of an object ; for only by intuition is the object
given, which is afterwards thought in accordance with the
1 Read diese for dieses and konnten for konnte. M.

228 APPENDIX C [268-269

Category. If I assert a thing to be a substance in pheno
menon, the predicates of its intuition must have been
previously given to me, by which I distinguish the per
manent from the changeable, and the substratum (thing in
itself) from what is merely attached to it. If I call a thing
simple in phenomenon, I mean by this that its intuition,
indeed, is part of my phenomena, but is itself not divisible,
etc. But if anything is known to be simple only in
concept, and not in appearance, then I have actually no
knowledge at all of the object, but only of my concept,
which I frame about something in general, and which is
not capable of being properly intuited. I only say that
I think a thing to be quite simple, because I can actually
say nothing more about it, except merely that it is some
thing.

Now, mere apperception (Ego) is in concept substance,
is in concept simple, etc., and so far all these psychological
dogmas have indisputable truth. Yet what we want to
know about the soul is not at all [269] discoverable in this
way ; for, since none of these predicates are valid of intuition,
and since therefore they can have no consequence applicable
to objects of experience, they are quite void. For the above
mentioned concept of substance does not teach me that the
soul continues to exist by itself, nor that it is a part of the
external intuitions, which cannot itself be further divided,
and which can, consequently, neither originate nor pass
away by any changes of nature : all of which are properties
which would make the soul cognoscible to me in the
connexion of experience, and might throw some light upon
its origin and future state. But when I assert by the mere
Category, that the soul is a simple substance, it is clear that
as the mere concept of substance contains nothing but this,
that a thing shall be represented as a subject per se, without

269-270] PARALOGISMS OF RATIONAL PSYCHOLOGY 229

also being the predicate of another, [it is clear, I say that]
from this concept no permanence follows, and that the
attribute of simplicity could certainly not add this per
manence ; so that we are not in the least informed of what
might happen to the soul in the changes of the world. If
we could be told that it is a simple part of matter, we might,
owing to what experience tells us, infer permanence, and
along with its simple nature indestructibility. But about
this, the concept of the Ego in the psychological first prin
ciple (I think) tells us not a word.

The following is the reason that the being which in us
imagines it can cognise itself by pure Categories, and
indeed by those which express absolute unity under each of
their classes. Apperception is itself the ground of the
possibility of the Categories, which on their side represent
nothing but the synthesis of the manifold in intuition, so far
as it has unity in apper- [270] ception. Hence, self-con
sciousness in general is the representation of that which is
the condition of all unity, and yet itself unconditioned.
Of the thinking Ego, then, or soul (which represents itself
as substance, simple, numerically identical at all times,
and the correlation of all existence, from which all other
existence must be inferred), we may say, that it does not
cognise itself through the Categories, but rather the Cate
gories, and through them all objects in the absolute unity
of apperception, viz. through itself. It is indeed quite
plain that what I must presuppose in order to cognise any
object at all, I cannot also cognise as an object ; and that
the determining self (thinking) is distinguished from the
determinable self (the thinking subject), as cognition is
from objects. Still nothing is more natural or seductive
than the illusion of considering the unity in the synthesis of
thoughts to be a perceived unity in the subject of these

23o APPENDIX C [270-271

thoughts. We might call it the subreption of hypostatised
consciousness (apperceptionis substantiates}^

If we wish to give its logical name to the paralogism in
the dialectical syllogisms of rational psychology, so far as
their premises are in themselves true, it may be called a
sophisma figura dictionis, in which the major premiss makes
merely a transcendental use of the Category with reference
to its condition, but the minor premiss and conclusion make
of the same Category an empirical use with reference to the
soul, which has been subsumed under this condition. So,
for example, in the paralogism of simplicity the concept of sub
stance is [2 7 1] a pure intellectual concept, which, without the
condition of sensuous intuition, is merely of transcendental,
that is, of no, use. But in the minor premiss the very same
concept is applied to the object of all internal experience,
yet without first establishing and laying down as a basis the
condition of its application in concrete^ that is, its per
manence ; hence, there is here an empirical, though
illegitimate, application made of it. In order to show the
systematic connexion of all these dialectical assertions in a
fallacious psychology, as connected in the pure Reason —
that is, in order to show its completeness — observe that the
apperception is carried through all the classes of the Cate
gories, but only applied to those concepts of the under
standing which in each [class] supply to the rest the basis
of unity in a possible perception, and these are — subsistence,
reality, unity (not plurality), and existence; only that
Reason here represents them as the conditions of the
possibility of a thinking being, which conditions are
themselves conditioned. Consequently, the soul cog
nises itself as —

1 I cannot but think that Mansel's theory of self being presented as
substance is here clearly refuted. M.

271-272] PARALOGISMS OF RATIONAL PSYCHOLOGY 231

1. The unconditioned unity of Relation, that is, not as
inhering, but subsisting;

2. The unconditioned unity of Quality -, that is, not as
a real whole, but simple ; 1

3. The unconditioned unity in plurality in time, that
is, not in different times numerically different, but as one
and the very same subject ;

4. The unconditioned unity of existence in space, that
[272] is, not as the consciousness of several things without
it, but only of its own existence, and of other things, on
the contrary, merely as its representations.

Reason is the faculty of principles. The assertions of
pure psychology do not contain empirical predicates of the
soul, but those which, if they occur, should determine the
object per se independent of experience, that is, through
the pure Reason. They must, then, be fairly based upon
principles and universal notions of thinking natures in
general. Instead of this, we find that the single represent
ation, / am, governs the whole of it, which, because it
expresses the pure formula of all my experience (indetermin
ately), announces itself as an universal proposition, valid for
all thinking beings ; and, as it is single from every point of
view, assumes the appearance of an absolute unity in the
conditions of thinking in general, and so extends itself
further than possible experience can reach.

1 How the simple here again corresponds to the Category of Reality,
I am as yet unable to show ; but it will be explained upon the occasion
of another rational use of the very same concept. [Simplicity corre
sponds to unconditioned Reality, for the reality of a composite whole
depends on that of each of its parts. B.]

[273] APPENDIX D

[Part of the gt/i Section of the Antinomy of the Pure
Reason .]

POSSIBILITY OF CAUSALITY THROUGH FREE
DOM IN HARMONY WITH THE UNIVERSAL
LAW OF NATURAL NECESSITY

That in an object of the senses which is not itself pheno
menon, I term intelligible. If, accordingly, an object
which must be regarded as a phenomenon in the sensuous
world possesses in itself [or per se] also a faculty which is
not an object of sensuous intuition, but by means of which
it is capable of being the cause of phenomena, the causality
of this being may be regarded from two different points of
view. The causality may be considered to be intelligible,
as regards its action — the action of a thing in itself — and
also sensible, as regards its effects as a phenomenon belonging
to the sensuous world.

We should, accordingly, have to form both an empirical
concept of the faculty of such a subject, as well as an
intellectual concept of its causality, which both occur
together in one and the same effect. This twofold manner
of thinking the faculty of a sensuous object does not run

273-274] INTELLIGIBLE AND EMPIRICAL CHARACTERS 233

counter to any of the concepts which we ought to form of
phenomena, or of possible experience; for as phenomena
— not being things in themselves — must have a transcend
ental [274] object as a foundation, which determines them
as mere representations, there seems to be no reason why
we should not ascribe to this transcendental object, in ad
dition to the property by means of which it appears, a
causality which is not a phenomenon, although its effects are
observed in the world of phenomena.

But every effective cause must possess a character — that
is to say, a law of its causality — without which it would not
be a cause at all. Accordingly, in a subject of the world
of sense we should have an empirical character, which
guaranteed that its actions, as phenomena, stand in complete
and harmonious connexion, conformably to unvarying natural
laws, with all other phenomena, and can be deduced from
these as conditions ; and that they do thus, in connexion
with these, constitute members of a single series in the
order of nature.

In the second place, we should be obliged to concede
to it an intelligible character also, by means of which it is
indeed the cause of those actions as phenomena, but which
is not itself a phenomenon, nor subordinate to the conditions
of the world of sense. The former may be termed the
character of the thing as a phenomenon; the latter, the
character of the thing as a thing per se.

Now this acting subject would, in its intelligible character,
be subject to no conditions of time; for time is only a
condition of phenomena, and not of things in themselves.
No action would begin or cease to be in this subject; it
would, consequently, be free from the law of all determina
tion of time — of all change — namely, that everything which
happens must have a cause in the phenomena (of the

II R

234

APPENDIX D [274-276

preceding state). In a word, the [275] causality of the sub
ject, in so far as it is intelligible, would not form a part of the
series of empirical conditions which necessitated the event
in the world of sense. Again, this intelligible character of
a thing could indeed never be immediately cognised, because
we can perceive nothing except so far as it appears, but it
must still be thought in accordance [or analogy] with the
empirical character ; just as we find ourselves compelled in
a general way, to place, in thought, a transcendental object at
the basis of phenomena, although we know nothing of what
it is in itself.

Accordingly, as to its empirical character, this subject,
being a phenomenon, would be subject to the causal nexus
in all the laws of its determination ; and it would so far be
nothing but a part of the world of sense, of which the effects
would follow without fail from nature, like every other
phenomenon. When influenced by external phenomena —
when cognised through experience in its empirical character,
i.e. in the law of its causality — all its actions must be
explicable according to natural laws, and all the requisites
for their complete and necessary determination must occur
in possible experience.

By virtue of its intelligible character, on the other hand
(although we possess only the general notion of this
character), the subject must be regarded as free from all
sensuous influences, and from all phenomenal determination.
Moreover, as nothing happens in this subject — as far as it
is a noumenon — and there does not, consequently, exist in
it any change demanding the dynamical determination of
time, and for the same reason no connexion with phenomena
as its causes — this active being must, in its actions, be so
far free [276] from and independent of natural necessity,
for this necessity exists only in sensibility. It would be

276-277] INTELLIGIBLE AND EMPIRICAL CHARACTERS 235

quite correct to say that it originates or begins its effects in
the world of sense from itself without the action beginning
in itself. We should not be in this case affirming that these
sensuous effects began to exist of themselves, because they
are always determined by prior empirical conditions, but
only by virtue of the empirical character (which is the
phenomenon of the intelligible character), and are possible
only as constituting a continuation of the series of natural
causes. And thus nature and freedom — each in its complete
signification — can meet, without contradiction or disagree
ment, in the same action, according as it is compared with
its intelligible or sensible cause.

FURTHER ELUCIDATION OF THE COSMOLOGICAL IDEA
OF FREEDOM IN CONNECTION WITH THE UNIVERSAL
LAW OF NATURAL NECESSITY.

I have thought it advisable to lay before the reader at
first a mere sketch of the solution of this transcendental
problem, in order to enable him to form with greater ease
a clear notion of the course which Reason must adopt in
the solution. I shall now proceed to exhibit the several
momenta of this solution, and to consider them in their
order. The natural law, that everything which happens
must have a cause ; that the causality of this cause, that is,
the action (which cannot always have existed, but must be
itself an event, for it precedes in [277] time some effect
which has then originated}, must have its cause among
phenomena by which it is determined ; and consequently,
that all events are empirically determined in an order
of nature — this law, I say, which lies at the foundation
of the possibility of experience and of a connected system
of phenomena, or nature, is a law of the understanding,

236 APPENDIX D [277-278

from which no departure, and to which no exception, can
be admitted. For to except even a single phenomenon
from its operation is to exclude it from the sphere of
possible experience, and make it a mere fiction of thought,
or phantom of the brain.

Thus we are obliged to acknowledge the existence of a
chain of causes, in the regress of which, however, absolute
totality cannot be found. But we need not detain ourselves
with this difficulty ; for it has already been removed in our
general discussion of the antinomy of the Reason, when it
attempts to reach the unconditioned in the series of phe
nomena. If we permit ourselves to be deceived by the
deception of transcendental realism, we shall find that
neither nature nor freedom remain. Here the only question
is : Whether, recognising nothing but natural necessity in
the whole series of events, it is possible to consider the
same effect as on the one hand an effect of nature, and on
the other an effect of freedom ; or, whether these two
species of causality are absolutely contradictory.

Among the causes in phenomena there can surely be
nothing which could commence a series absolutely, and of
itself. Every action, as phenomenon, so far as it produces
an event, is itself an event or occurrence presupposing
another state, in which its cause is to be found. [278] Thus
everything that happens is but a continuation of the series ;
and no commencement, starting of itself, is here possible.
The actions of natural causes are accordingly themselves
effects, and presuppose causes preceding them in time.
An original action — an action by which something happens
which was not previously — is beyond the causal connexion
of phenomena.

Now, is it necessary that, granting all effects to
be phenomena, the causality of their cause, which (cause)

278-279] INTELLIGIBLE AND EMPIRICAL CHARACTERS 237

is itself a phenomenon, must belong to the empirical world ? l
Is it not rather possible that, although for every effect in the
phenomenon a connexion with its cause according to the laws
of empirical causality is required, this empirical causality
may be itself an effect of a causality not empirical, but
intelligible — its connexion with natural causes remaining,
nevertheless, intact?

Such a causality would be considered, in reference to
phenomena, as the original action of a cause which is in so
far, therefore, not phenomenal, but, as regards this faculty,
intelligible, although the cause must at the same time, as a
link in the chain of nature, be regarded as belonging to
the sensuous world.

A belief in the causality of phenomena among each
other is necessary, if we are required to look for and give
an account of the natural conditions of natural [279] events;
that is to say, their causes in phenomena. This being
admitted as unexceptionably valid, the requirements of the
understanding, which recognises nothing but nature, and is
entitled to it, are satisfied ; and our physical explanations
may proceed in their regular course, without let or
hindrance.

But it is no stumbling-block in the way, even assuming
it to be a mere fiction, to admit that there are some2
natural causes which have a faculty that is only intelligible,
inasmuch as it is not determined to action by empirical

1 The reader will observe that Kant uses the word cause for the total
subject of the causality both noumenal and phenomenal, and distinctly
speaks of the causality — even the intelligible causality — of a thing as
different from the thing (cause) itself. Here he differs from Hamilton,
and, I must -add, agrees with common sense. M.

2 This is a distinct statement, and opposed to Kuno Fischer's
account of the matter, Comm. p. 243. Fischer substitutes all for Kant's
some. M.

238 APPENDIX D [279-280

conditions, but solely upon grounds of the understanding ;
so, however, that the action in the phenomenon of this
cause must be in accordance with all the laws of empirical
causality.

Thus the acting subject, as a causa phenomenon, would
continue to preserve a complete connexion with nature and
natural conditions ; and only the noumenon of this subject
(with all its causality in the phenomenon) would contain
certain conditions, which, if we ascend from the empirical
to the transcendental object, must be regarded as merely
intelligible. For if we attend, in our inquiries with regard
to causes in the world of phenomena, to the directions of
nature alone, we need not trouble ourselves about what
sort of basis is conceived for these phenomena and their
natural connexion in the transcendental subject (which is
empirically unknown to us).

This intelligible ground of phenomena does not concern
empirical questions. Perhaps it has only to do [2 80] with
thinking in the pure understanding; and, although the
effects of this thinking and acting of the pure understanding
are discoverable in phenomena, these phenomena must,
nevertheless, be capable of a full and complete explanation,
in accordance with natural laws. And in this case we
attend solely to their empirical (as the highest ground of
explanation), and omit all consideration of their intelligible,
character (which is the transcendental cause of the former),
as completely unknown, except in so far as it is indicated
by the latter as its sensuous symbol.

Now let us apply this to experience. Man is one of the
phenomena of the sensuous world, and so far also one of
the natural causes, the causality of which must be regulated
by empirical laws. As such, he must possess an empirical
character, like all other objects of nature. We remark this

280-281] INTELLIGIBLE AND EMPIRICAL CHARACTERS 239

empirical character in his effects, which reveal the presence
of certain powers and faculties. If we consider inanimate
or merely brute nature, we can discover no reason for
conceiving any faculty to be determined otherwise than in
a purely sensuous manner.

But man, to whom the rest of nature reveals herself only
through sense, cognises himself (not only by his senses,
but) also through mere apperception ; and this in actions
and internal determinings, which he cannot regard as
sensuous impressions. He is thus to himself on the one
hand indeed a phenomenon ; but on the other, in respect
of certain faculties, a purely intelligible object — intelligible,
because its action cannot be ascribed to the receptivity of
sensibility. We call these faculties understanding and
Reason.

The latter, especially, is in a peculiar manner distinct
[281] from all empirically-conditioned faculties; for it con
siders its objects merely in accordance with Ideas, and by
means of these determines the understanding, which then
proceeds to make an empirical use of its concepts, which
indeed are also pure.1

1 The remainder of the discussion is rendered much less inaccurately
by Mr. Meiklejohn (pp. 338 jy<?.); I have, therefore, not thought it
necessary to repeat it here. M.

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Kant, Immanuel B

2779

Kant's critical phil. for .M27 ".
English readers vol.2