PREFACE TO THE SECOND EDITION, 1787
Whether the treatment of that portion of our knowledge which lies
within the province of pure reason advances with that undeviating
certainty which characterizes the progress of science, we shall be
at no loss to determine. If we find those who are engaged in
metaphysical pursuits, unable to come to an understanding as to the
method which they ought to follow; if we find them, after the most
elaborate preparations, invariably brought to a stand before the
goal is reached, and compelled to retrace their steps and strike
into fresh paths, we may then feel quite sure that they are far from
having attained to the certainty of scientific progress and may rather
be said to be merely groping about in the dark. In these circumstances
we shall render an important service to reason if we succeed in simply
indicating the path along which it must travel, in order to arrive
at any results- even if it should be found necessary to abandon many
of those aims which, without reflection, have been proposed for its
attainment.
That logic has advanced in this sure course, even from the
earliest times, is apparent from the fact that, since Aristotle, it
has been unable to advance a step and, thus, to all appearance has
reached its completion. For, if some of the moderns have thought to
enlarge its domain by introducing psychological discussions on the
mental faculties, such as imagination and wit, metaphysical,
discussions on the origin of knowledge and the different kinds of
certitude, according to the difference of the objects (idealism,
scepticism, and so on), or anthropological discussions on
prejudices, their causes and remedies: this attempt, on the part of
these authors, only shows their ignorance of the peculiar nature of
logical science. We do not enlarge but disfigure the sciences when
we lose sight of their respective limits and allow them to run into
one another. Now logic is enclosed within limits which admit of
perfectly clear definition; it is a science which has for its object
nothing but the exposition and proof of the formal laws of all
thought, whether it be a priori or empirical, whatever be its origin
or its object, and whatever the difficulties- natural or accidental-
which it encounters in the human mind.
The early success of logic must be attributed exclusively to the
narrowness of its field, in which abstraction may, or rather must,
be made of all the objects of cognition with their characteristic
distinctions, and in which the understanding has only to deal with
itself and with its own forms. It is, obviously, a much more difficult
task for reason to strike into the sure path of science, where it
has to deal not simply with itself, but with objects external to
itself. Hence, logic is properly only a propaedeutic- forms, as it
were, the vestibule of the sciences; and while it is necessary to
enable us to form a correct judgement with regard to the various
branches of knowledge, still the acquisition of real, substantive
knowledge is to be sought only in the sciences properly so called,
that is, in the objective sciences.
Now these sciences, if they can be termed rational at all, must
contain elements of a priori cognition, and this cognition may stand
in a twofold relation to its object. Either it may have to determine
the conception of the object- which must be supplied extraneously,
or it may have to establish its reality. The former is theoretical,
the latter practical, rational cognition. In both, the pure or a
priori element must be treated first, and must be carefully
distinguished from that which is supplied from other sources. Any
other method can only lead to irremediable confusion.
Mathematics and physics are the two theoretical sciences which
have to determine their objects a priori. The former is purely a
priori, the latter is partially so, but is also dependent on other
sources of cognition.
In the earliest times of which history affords us any record,
mathematics had already entered on the sure course of science, among
that wonderful nation, the Greeks. Still it is not to be supposed that
it was as easy for this science to strike into, or rather to construct
for itself, that royal road, as it was for logic, in which reason
has only to deal with itself. On the contrary, I believe that it
must have remained long- chiefly among the Egyptians- in the stage
of blind groping after its true aims and destination, and that it
was revolutionized by the happy idea of one man, who struck out and
determined for all time the path which this science must follow, and
which admits of an indefinite advancement. The history of this
intellectual revolution- much more important in its results than the
discovery of the passage round the celebrated Cape of Good Hope- and
of its author, has not been preserved. But Diogenes Laertius, in
naming the supposed discoverer of some of the simplest elements of
geometrical demonstration- elements which, according to the ordinary
opinion, do not even require to be proved- makes it apparent that
the change introduced by the first indication of this new path, must
have seemed of the utmost importance to the mathematicians of that
age, and it has thus been secured against the chance of oblivion. A
new light must have flashed on the mind of the first man (Thales, or
whatever may have been his name) who demonstrated the properties of
the isosceles triangle. For he found that it was not sufficient to
meditate on the figure, as it lay before his eyes, or the conception
of it, as it existed in his mind, and thus endeavour to get at the
knowledge of its properties, but that it was necessary to produce
these properties, as it were, by a positive a priori construction; and
that, in order to arrive with certainty at a priori cognition, he must
not attribute to the object any other properties than those which
necessarily followed from that which he had himself, in accordance
with his conception, placed in the object.
A much longer period elapsed before physics entered on the highway
of science. For it is only about a century and a half since the wise
Bacon gave a new direction to physical studies, or rather- as others
were already on the right track- imparted fresh vigour to the
pursuit of this new direction. Here, too, as in the case of
mathematics, we find evidence of a rapid intellectual revolution. In
the remarks which follow I shall confine myself to the empirical
side of natural science.
When Galilei experimented with balls of a definite weight on the
inclined plane, when Torricelli caused the air to sustain a weight
which he had calculated beforehand to be equal to that of a definite
column of water, or when Stahl, at a later period, converted metals
into lime, and reconverted lime into metal, by the addition and
subtraction of certain elements;* a light broke upon all natural
philosophers. They learned that reason only perceives that which it
produces after its own design; that it must not be content to
follow, as it were, in the leading-strings of nature, but must proceed
in advance with principles of judgement according to unvarying laws,
and compel nature to reply its questions. For accidental observations,
made according to no preconceived plan, cannot be united under a
necessary law. But it is this that reason seeks for and requires. It
is only the principles of reason which can give to concordant
phenomena the validity of laws, and it is only when experiment is
directed by these rational principles that it can have any real
utility. Reason must approach nature with the view, indeed, of
receiving information from it, not, however, in the character of a
pupil, who listens to all that his master chooses to tell him, but
in that of a judge, who compels the witnesses to reply to those
questions which he himself thinks fit to propose. To this single
idea must the revolution be ascribed, by which, after groping in the
dark for so many centuries, natural science was at length conducted
into the path of certain progress.
*I do not here follow with exactness the history of the experimental
method, of which, indeed, the first steps are involved in some
obscurity.
We come now to metaphysics, a purely speculative science, which
occupies a completely isolated position and is entirely independent of
the teachings of experience. It deals with mere conceptions- not, like
mathematics, with conceptions applied to intuition- and in it,
reason is the pupil of itself alone. It is the oldest of the sciences,
and would still survive, even if all the rest were swallowed up in the
abyss of an all-destroying barbarism. But it has not yet had the
good fortune to attain to the sure scientific method. This will be
apparent; if we apply the tests which we proposed at the outset. We
find that reason perpetually comes to a stand, when it attempts to
gain a priori the perception even of those laws which the most
common experience confirms. We find it compelled to retrace its
steps in innumerable instances, and to abandon the path on which it
had entered, because this does not lead to the desired result. We
find, too, that those who are engaged in metaphysical pursuits are far
from being able to agree among themselves, but that, on the
contrary, this science appears to furnish an arena specially adapted
for the display of skill or the exercise of strength in mock-contests-
a field in which no combatant ever yet succeeded in gaining an inch of
ground, in which, at least, no victory was ever yet crowned with
permanent possession.
This leads us to inquire why it is that, in metaphysics, the sure
path of science has not hitherto been found. Shall we suppose that
it is impossible to discover it? Why then should nature have visited
our reason with restless aspirations after it, as if it were one of
our weightiest concerns? Nay, more, how little cause should we have to
place confidence in our reason, if it abandons us in a matter about
which, most of all, we desire to know the truth- and not only so,
but even allures us to the pursuit of vain phantoms, only to betray us
in the end? Or, if the path has only hitherto been missed, what
indications do we possess to guide us in a renewed investigation,
and to enable us to hope for greater success than has fallen to the
lot of our predecessors?
It appears to me that the examples of mathematics and natural
philosophy, which, as we have seen, were brought into their present
condition by a sudden revolution, are sufficiently remarkable to fix
our attention on the essential circumstances of the change which has
proved so advantageous to them, and to induce us to make the
experiment of imitating them, so far as the analogy which, as rational
sciences, they bear to metaphysics may permit. It has hitherto been
assumed that our cognition must conform to the objects; but all
attempts to ascertain anything about these objects a priori, by
means of conceptions, and thus to extend the range of our knowledge,
have been rendered abortive by this assumption. Let us then make the
experiment whether we may not be more successful in metaphysics, if we
assume that the objects must conform to our cognition. This appears,
at all events, to accord better with the possibility of our gaining
the end we have in view, that is to say, of arriving at the
cognition of objects a priori, of determining something with respect
to these objects, before they are given to us. We here propose to do
just what Copernicus did in attempting to explain the celestial
movements. When he found that he could make no progress by assuming
that all the heavenly bodies revolved round the spectator, he reversed
the process, and tried the experiment of assuming that the spectator
revolved, while the stars remained at rest. We may make the same
experiment with regard to the intuition of objects. If the intuition
must conform to the nature of the objects, I do not see how we can
know anything of them a priori. If, on the other hand, the object
conforms to the nature of our faculty of intuition, I can then
easily conceive the possibility of such an a priori knowledge. Now
as I cannot rest in the mere intuitions, but- if they are to become
cognitions- must refer them, as representations, to something, as
object, and must determine the latter by means of the former, here
again there are two courses open to me. Either, first, I may assume
that the conceptions, by which I effect this determination, conform to
the object- and in this case I am reduced to the same perplexity as
before; or secondly, I may assume that the objects, or, which is the
same thing, that experience, in which alone as given objects they
are cognized, conform to my conceptions- and then I am at no loss
how to proceed. For experience itself is a mode of cognition which
requires understanding. Before objects, are given to me, that is, a
priori, I must presuppose in myself laws of the understanding which
are expressed in conceptions a priori. To these conceptions, then, all
the objects of experience must necessarily conform. Now there are
objects which reason thinks, and that necessarily, but which cannot be
given in experience, or, at least, cannot be given so as reason thinks
them. The attempt to think these objects will hereafter furnish an
excellent test of the new method of thought which we have adopted, and
which is based on the principle that we only cognize in things a
priori that which we ourselves place in them.*
*This method, accordingly, which we have borrowed from the natural
philosopher, consists in seeking for the elements of pure reason in
that which admits of confirmation or refutation by experiment. Now the
propositions of pure reason, especially when they transcend the limits
of possible experience, do not admit of our making any experiment with
their objects, as in natural science. Hence, with regard to those
conceptions and principles which we assume a priori, our only course
ill be to view them from two different sides. We must regard one and
the same conception, on the one hand, in relation to experience as
an object of the senses and of the understanding, on the other hand,
in relation to reason, isolated and transcending the limits of
experience, as an object of mere thought. Now if we find that, when we
regard things from this double point of view, the result is in harmony
with the principle of pure reason, but that, when we regard them
from a single point of view, reason is involved in self-contradiction,
then the experiment will establish the correctness of this
distinction.
This attempt succeeds as well as we could desire, and promises to
metaphysics, in its first part- that is, where it is occupied with
conceptions a priori, of which the corresponding objects may be
given in experience- the certain course of science. For by this new
method we are enabled perfectly to explain the possibility of a priori
cognition, and, what is more, to demonstrate satisfactorily the laws
which lie a priori at the foundation of nature, as the sum of the
objects of experience- neither of which was possible according to
the procedure hitherto followed. But from this deduction of the
faculty of a priori cognition in the first part of metaphysics, we
derive a surprising result, and one which, to all appearance,
militates against the great end of metaphysics, as treated in the
second part. For we come to the conclusion that our faculty of
cognition is unable to transcend the limits of possible experience;
and yet this is precisely the most essential object of this science.
The estimate of our rational cognition a priori at which we arrive
is that it has only to do with phenomena, and that things in
themselves, while possessing a real existence, lie beyond its
sphere. Here we are enabled to put the justice of this estimate to the
test. For that which of necessity impels us to transcend the limits of
experience and of all phenomena is the unconditioned, which reason
absolutely requires in things as they are in themselves, in order to
complete the series of conditions. Now, if it appears that when, on
the one hand, we assume that our cognition conforms to its objects
as things in themselves, the unconditioned cannot be thought without
contradiction, and that when, on the other hand, we assume that our
representation of things as they are given to us, does not conform
to these things as they are in themselves, but that these objects,
as phenomena, conform to our mode of representation, the contradiction
disappears: we shall then be convinced of the truth of that which we
began by assuming for the sake of experiment; we may look upon it as
established that the unconditioned does not lie in things as we know
them, or as they are given to us, but in things as they are in
themselves, beyond the range of our cognition.*
*This experiment of pure reason has a great similarity to that of
the chemists, which they term the experiment of reduction, or, more
usually, the synthetic process. The analysis of the metaphysician
separates pure cognition a priori into two heterogeneous elements,
viz., the cognition of things as phenomena, and of things in
themselves. Dialectic combines these again into harmony with the
necessary rational idea of the unconditioned, and finds that this
harmony never results except through the above distinction, which
is, therefore, concluded to be just.
But, after we have thus denied the power of speculative reason to
make any progress in the sphere of the supersensible, it still remains
for our consideration whether data do not exist in practical cognition
which may enable us to determine the transcendent conception of the
unconditioned, to rise beyond the limits of all possible experience
from a practical point of view, and thus to satisfy the great ends
of metaphysics. Speculative reason has thus, at least, made room for
such an extension of our knowledge: and, if it must leave this space
vacant, still it does not rob us of the liberty to fill it up, if we
can, by means of practical data- nay, it even challenges us to make
the attempt.*
*So the central laws of the movements of the heavenly bodies
established the truth of that which Copernicus, first, assumed only as
a hypothesis, and, at the same time, brought to light that invisible
force (Newtonian attraction) which holds the universe together. The
latter would have remained forever undiscovered, if Copernicus had not
ventured on the experiment- contrary to the senses but still just-
of looking for the observed movements not in the heavenly bodies,
but in the spectator. In this Preface I treat the new metaphysical
method as a hypothesis with the view of rendering apparent the first
attempts at such a change of method, which are always hypothetical.
But in the Critique itself it will be demonstrated, not
hypothetically, but apodeictically, from the nature of our
representations of space and time. and from the elementary conceptions
of the understanding.
This attempt to introduce a complete revolution in the procedure
of metaphysics, after the example of the geometricians and natural
philosophers, constitutes the aim of the Critique of Pure
Speculative Reason. It is a treatise on the method to be followed, not
a system of the science itself. But, at the same time, it marks out
and defines both the external boundaries and the internal structure of
this science. For pure speculative reason has this peculiarity,
that, in choosing the various objects of thought, it is able to define
the limits of its own faculties, and even to give a complete
enumeration of the possible modes of proposing problems to itself, and
thus to sketch out the entire system of metaphysics. For, on the one
hand, in cognition a priori, nothing must be attributed to the objects
but what the thinking subject derives from itself; and, on the other
hand, reason is, in regard to the principles of cognition, a perfectly
distinct, independent unity, in which, as in an organized body,
every member exists for the sake of the others, and all for the sake
of each, so that no principle can be viewed, with safety, in one
relationship, unless it is, at the same time, viewed in relation to
the total use of pure reason. Hence, too, metaphysics has this
singular advantage- an advantage which falls to the lot of no other
science which has to do with objects- that, if once it is conducted
into the sure path of science, by means of this criticism, it can then
take in the whole sphere of its cognitions, and can thus complete
its work, and leave it for the use of posterity, as a capital which
can never receive fresh accessions. For metaphysics has to deal only
with principles and with the limitations of its own employment as
determined by these principles. To this perfection it is, therefore,
bound, as the fundamental science, to attain, and to it the maxim
may justly be applied:
Nil actum reputans, si quid superesset agendum.*
*"He considered nothing done, so long as anything remained to be
done."
But, it will be asked, what kind of a treasure is this that we
propose to bequeath to posterity? What is the real value of this
system of metaphysics, purified by criticism, and thereby reduced to a
permanent condition? A cursory view of the present work will lead to
the supposition that its use is merely negative, that it only serves
to warn us against venturing, with speculative reason, beyond the
limits of experience. This is, in fact, its primary use. But this,
at once, assumes a positive value, when we observe that the principles
with which speculative reason endeavours to transcend its limits
lead inevitably, not to the extension, but to the contraction of the
use of reason, inasmuch as they threaten to extend the limits of
sensibility, which is their proper sphere, over the entire realm of
thought and, thus, to supplant the pure (practical) use of reason.
So far, then, as this criticism is occupied in confining speculative
reason within its proper bounds, it is only negative; but, inasmuch as
it thereby, at the same time, removes an obstacle which impedes and
even threatens to destroy the use of practical reason, it possesses
a positive and very important value. In order to admit this, we have
only to be convinced that there is an absolutely necessary use of pure
reason- the moral use- in which it inevitably transcends the limits of
sensibility, without the aid of speculation, requiring only to be
insured against the effects of a speculation which would involve it in
contradiction with itself. To deny the positive advantage of the
service which this criticism renders us would be as absurd as. to
maintain that the system of police is productive of no positive
benefit, since its main business is to prevent the violence which
citizen has to apprehend from citizen, that so each may pursue his
vocation in peace and security. That space and time are only forms
of sensible intuition, and hence are only conditions of the
existence of things as phenomena; that, moreover, we have no
conceptions of the understanding, and, consequently, no elements for
the cognition of things, except in so far as a corresponding intuition
can be given to these conceptions; that, accordingly, we can have no
cognition of an object, as a thing in itself, but only as an object of
sensible intuition, that is, as phenomenon- all this is proved in
the analytical part of the Critique; and from this the limitation of
all possible speculative cognition to the mere objects of
experience, follows as a necessary result. At the same time, it must
be carefully borne in mind that, while we surrender the power of
cognizing, we still reserve the power of thinking objects, as things
in themselves.* For, otherwise, we should require to affirm the
existence of an appearance, without something that appears- which
would be absurd. Now let us suppose, for a moment, that we had not
undertaken this criticism and, accordingly, had not drawn the
necessary distinction between things as objects of experience and
things as they are in themselves. The principle of causality, and,
by consequence, the mechanism of nature as determined by causality,
would then have absolute validity in relation to all things as
efficient causes. I should then be unable to assert, with regard to
one and the same being, e.g., the human soul, that its will is free,
and yet, at the same time, subject to natural necessity, that is,
not free, without falling into a palpable contradiction, for in both
propositions I should take the soul in the same signification, as a
thing in general, as a thing in itself- as, without previous
criticism, I could not but take it. Suppose now, on the other hand,
that we have undertaken this criticism, and have learnt that an object
may be taken in two senses, first, as a phenomenon, secondly, as a
thing in itself; and that, according to the deduction of the
conceptions of the understanding, the principle of causality has
reference only to things in the first sense. We then see how it does
not involve any contradiction to assert, on the one hand, that the
will, in the phenomenal sphere- in visible action- is necessarily
obedient to the law of nature, and, in so far, not free; and, on the
other hand, that, as belonging to a thing in itself, it is not subject
to that law, and, accordingly, is free. Now, it is true that I cannot,
by means of speculative reason, and still less by empirical
observation, cognize my soul as a thing in itself and consequently,
cannot cognize liberty as the property of a being to which I ascribe
effects in the world of sense. For, to do so, I must cognize this
being as existing, and yet not in time, which- since I cannot
support my conception by any intuition- is impossible. At the same
time, while I cannot cognize, I can quite well think freedom, that
is to say, my representation of it involves at least no contradiction,
if we bear in mind the critical distinction of the two modes of
representation (the sensible and the intellectual) and the
consequent limitation of the conceptions of the pure understanding and
of the principles which flow from them. Suppose now that morality
necessarily presupposed liberty, in the strictest sense, as a property
of our will; suppose that reason contained certain practical, original
principles a priori, which were absolutely impossible without this
presupposition; and suppose, at the same time, that speculative reason
had proved that liberty was incapable of being thought at all. It
would then follow that the moral presupposition must give way to the
speculative affirmation, the opposite of which involves an obvious
contradiction, and that liberty and, with it, morality must yield to
the mechanism of nature; for the negation of morality involves no
contradiction, except on the presupposition of liberty. Now morality
does not require the speculative cognition of liberty; it is enough
that I can think it, that its conception involves no contradiction,
that it does not interfere with the mechanism of nature. But even this
requirement we could not satisfy, if we had not learnt the twofold
sense in which things may be taken; and it is only in this way that
the doctrine of morality and the doctrine of nature are confined
within their proper limits. For this result, then, we are indebted
to a criticism which warns us of our unavoidable ignorance with regard
to things in themselves, and establishes the necessary limitation of
our theoretical cognition to mere phenomena.
*In order to cognize an object, I must be able to prove its
possibility, either from its reality as attested by experience, or a
priori, by means of reason. But I can think what I please, provided
only I do not contradict myself; that is, provided my conception is
a possible thought, though I may be unable to answer for the existence
of a corresponding object in the sum of possibilities. But something
more is required before I can attribute to such a conception objective
validity, that is real possibility- the other possibility being merely
logical. We are not, however, confined to theoretical sources of
cognition for the means of satisfying this additional requirement, but
may derive them from practical sources.
The positive value of the critical principles of pure reason in
relation to the conception of God and of the simple nature of the
soul, admits of a similar exemplification; but on this point I shall
not dwell. I cannot even make the assumption- as the practical
interests of morality require- of God, freedom, and immortality, if
I do not deprive speculative reason of its pretensions to transcendent
insight. For to arrive at these, it must make use of principles which,
in fact, extend only to the objects of possible experience, and
which cannot be applied to objects beyond this sphere without
converting them into phenomena, and thus rendering the practical
extension of pure reason impossible. I must, therefore, abolish
knowledge, to make room for belief. The dogmatism of metaphysics, that
is, the presumption that it is possible to advance in metaphysics
without previous criticism, is the true source of the unbelief (always
dogmatic) which militates against morality.
Thus, while it may be no very difficult task to bequeath a legacy to
posterity, in the shape of a system of metaphysics constructed in
accordance with the Critique of Pure Reason, still the value of such a
bequest is not to be depreciated. It will render an important
service to reason, by substituting the certainty of scientific
method for that random groping after results without the guidance of
principles, which has hitherto characterized the pursuit of
metaphysical studies. It will render an important service to the
inquiring mind of youth, by leading the student to apply his powers to
the cultivation of. genuine science, instead of wasting them, as at
present, on speculations which can never lead to any result, or on the
idle attempt to invent new ideas and opinions. But, above all, it will
confer an inestimable benefit on morality and religion, by showing
that all the objections urged against them may be silenced for ever by
the Socratic method, that is to say, by proving the ignorance of the
objector. For, as the world has never been, and, no doubt, never
will be without a system of metaphysics of one kind or another, it
is the highest and weightiest concern of philosophy to render it
powerless for harm, by closing up the sources of error.
This important change in the field of the sciences, this loss of its
fancied possessions, to which speculative reason must submit, does not
prove in any way detrimental to the general interests of humanity. The
advantages which the world has derived from the teachings of pure
reason are not at all impaired. The loss falls, in its whole extent,
on the monopoly of the schools, but does not in the slightest degree
touch the interests of mankind. I appeal to the most obstinate
dogmatist, whether the proof of the continued existence of the soul
after death, derived from the simplicity of its substance; of the
freedom of the will in opposition to the general mechanism of
nature, drawn from the subtle but impotent distinction of subjective
and objective practical necessity; or of the existence of God, deduced
from the conception of an ens realissimum- the contingency of the
changeable, and the necessity of a prime mover, has ever been able
to pass beyond the limits of the schools, to penetrate the public
mind, or to exercise the slightest influence on its convictions. It
must be admitted that this has not been the case and that, owing to
the unfitness of the common understanding for such subtle
speculations, it can never be expected to take place. On the contrary,
it is plain that the hope of a future life arises from the feeling,
which exists in the breast of every man, that the temporal is
inadequate to meet and satisfy the demands of his nature. In like
manner, it cannot be doubted that the clear exhibition of duties in
opposition to all the claims of inclination, gives rise to the
consciousness of freedom, and that the glorious order, beauty, and
providential care, everywhere displayed in nature, give rise to the
belief in a wise and great Author of the Universe. Such is the genesis
of these general convictions of mankind, so far as they depend on
rational grounds; and this public property not only remains
undisturbed, but is even raised to greater importance, by the doctrine
that the schools have no right to arrogate to themselves a more
profound insight into a matter of general human concernment than
that to which the great mass of men, ever held by us in the highest
estimation, can without difficulty attain, and that the schools
should, therefore, confine themselves to the elaboration of these
universally comprehensible and, from a moral point of view, amply
satisfactory proofs. The change, therefore, affects only the
arrogant pretensions of the schools, which would gladly retain, in
their own exclusive possession, the key to the truths which they
impart to the public.
Quod mecum nescit, solus vult scire videri.
At the same time it does not deprive the speculative philosopher of
his just title to be the sole depositor of a science which benefits
the public without its knowledge- I mean, the Critique of Pure Reason.
This can never become popular and, indeed, has no occasion to be so;
for finespun arguments in favour of useful truths make just as
little impression on the public mind as the equally subtle
objections brought against these truths. On the other hand, since both
inevitably force themselves on every man who rises to the height of
speculation, it becomes the manifest duty of the schools to enter upon
a thorough investigation of the rights of speculative reason and,
thus, to prevent the scandal which metaphysical controversies are
sure, sooner or later, to cause even to the masses. It is only by
criticism that metaphysicians (and, as such, theologians too) can be
saved from these controversies and from the consequent perversion of
their doctrines. Criticism alone can strike a blow at the root of
materialism, fatalism, atheism, free-thinking, fanaticism, and
superstition, which are universally injurious- as well as of
idealism and scepticism, which are dangerous to the schools, but can
scarcely pass over to the public. If governments think proper to
interfere with the affairs of the learned, it would be more consistent
with a wise regard for the interests of science, as well as for
those of society, to favour a criticism of this kind, by which alone
the labours of reason can be established on a firm basis, than to
support the ridiculous despotism of the schools, which raise a loud
cry of danger to the public over the destruction of cobwebs, of
which the public has never taken any notice, and the loss of which,
therefore, it can never feel.
This critical science is not opposed to the dogmatic procedure of
reason in pure cognition; for pure cognition must always be
dogmatic, that is, must rest on strict demonstration from sure
principles a priori- but to dogmatism, that is, to the presumption
that it is possible to make any progress with a pure cognition,
derived from (philosophical) conceptions, according to the
principles which reason has long been in the habit of employing-
without first inquiring in what way and by what right reason has
come into the possession of these principles. Dogmatism is thus the
dogmatic procedure of pure reason without previous criticism of its
own powers, and in opposing this procedure, we must not be supposed to
lend any countenance to that loquacious shallowness which arrogates to
itself the name of popularity, nor yet to scepticism, which makes
short work with the whole science of metaphysics. On the contrary, our
criticism is the necessary preparation for a thoroughly scientific
system of metaphysics which must perform its task entirely a priori,
to the complete satisfaction of speculative reason, and must,
therefore, be treated, not popularly, but scholastically. In
carrying out the plan which the Critique prescribes, that is, in the
future system of metaphysics, we must have recourse to the strict
method of the celebrated Wolf, the greatest of all dogmatic
philosophers. He was the first to point out the necessity of
establishing fixed principles, of clearly defining our conceptions,
and of subjecting our demonstrations to the most severe scrutiny,
instead of rashly jumping at conclusions. The example which he set
served to awaken that spirit of profound and thorough investigation
which is not yet extinct in Germany. He would have been peculiarly
well fitted to give a truly scientific character to metaphysical
studies, had it occurred to him to prepare the field by a criticism of
the organum, that is, of pure reason itself. That be failed to
perceive the necessity of such a procedure must be ascribed to the
dogmatic mode of thought which characterized his age, and on this
point the philosophers of his time, as well as of all previous
times, have nothing to reproach each other with. Those who reject at
once the method of Wolf, and of the Critique of Pure Reason, can
have no other aim but to shake off the fetters of science, to change
labour into sport, certainty into opinion, and philosophy into
philodoxy.
In this second edition, I have endeavoured, as far as possible, to
remove the difficulties and obscurity which, without fault of mine
perhaps, have given rise to many misconceptions even among acute
thinkers. In the propositions themselves, and in the demonstrations by
which they are supported, as well as in the form and the entire plan
of the work, I have found nothing to alter; which must be attributed
partly to the long examination to which I had subjected the whole
before offering it to the public and partly to the nature of the case.
For pure speculative reason is an organic structure in which there
is nothing isolated or independent, but every Single part is essential
to all the rest; and hence, the slightest imperfection, whether defect
or positive error, could not fail to betray itself in use. I
venture, further, to hope, that this system will maintain the same
unalterable character for the future. I am led to entertain this
confidence, not by vanity, but by the evidence which the equality of
the result affords, when we proceed, first, from the simplest elements
up to the complete whole of pure reason and, and then, backwards
from the whole to each part. We find that the attempt to make the
slightest alteration, in any part, leads inevitably to contradictions,
not merely in this system, but in human reason itself. At the same
time, there is still much room for improvement in the exposition of
the doctrines contained in this work. In the present edition, I have
endeavoured to remove misapprehensions of the aesthetical part,
especially with regard to the conception of time; to clear away the
obscurity which has been found in the deduction of the conceptions
of the understanding; to supply the supposed want of sufficient
evidence in the demonstration of the principles of the pure
understanding; and, lastly, to obviate the misunderstanding of the
paralogisms which immediately precede the rational psychology.
Beyond this point- the end of the second main division of the
"Transcendental Dialectic"- I have not extended my alterations,*
partly from want of time, and partly because I am not aware that any
portion of the remainder has given rise to misconceptions among
intelligent and impartial critics, whom I do not here mention with
that praise which is their due, but who will find that their
suggestions have been attended to in the work itself.
*The only addition, properly so called- and that only in the
method of proof- which I have made in the present edition, consists of
a new refutation of psychological idealism, and a strict
demonstration- the only one possible, as I believe- of the objective
reality of external intuition. However harmless idealism may be
considered- although in reality it is not so- in regard to the
essential ends of metaphysics, it must still remain a scandal to
philosophy and to the general human reason to be obliged to assume, as
an article of mere belief, the existence of things external to
ourselves (from which, yet, we derive the whole material of
cognition for the internal sense), and not to be able to oppose a
satisfactory proof to any one who may call it in question. As there is
some obscurity of expression in the demonstration as it stands in
the text, I propose to alter the passage in question as follows:
"But this permanent cannot be an intuition in me. For all the
determining grounds of my existence which can be found in me are
representations and, as such, do themselves require a permanent,
distinct from them, which may determine my existence in relation to
their changes, that is, my existence in time, wherein they change." It
may, probably, be urged in opposition to this proof that, after all, I
am only conscious immediately of that which is in me, that is, of my
representation of external things, and that, consequently, it must
always remain uncertain whether anything corresponding to this
representation does or does not exist externally to me. But I am
conscious, through internal experience, of my existence in time
(consequently, also, of the determinability of the former in the
latter), and that is more than the simple consciousness of my
representation. It is, in fact, the same as the empirical
consciousness of my existence, which can only be determined in
relation to something, which, while connected with my existence, is
external to me. This consciousness of my existence in time is,
therefore, identical with the consciousness of a relation to something
external to me, and it is, therefore, experience, not fiction,
sense, not imagination, which inseparably connects the external with
my internal sense. For the external sense is, in itself, the
relation of intuition to something real, external to me; and the
reality of this something, as opposed to the mere imagination of it,
rests solely on its inseparable connection with internal experience as
the condition of its possibility. If with the intellectual
consciousness of my existence, in the representation: I am, which
accompanies all my judgements, and all the operations of my
understanding, I could, at the same time, connect a determination of
my existence by intellectual intuition, then the consciousness of a
relation to something external to me would not be necessary. But the
internal intuition in which alone my existence can be determined,
though preceded by that purely intellectual consciousness, is itself
sensible and attached to the condition of time. Hence this
determination of my existence, and consequently my internal experience
itself, must depend on something permanent which is not in me, which
can be, therefore, only in something external to me, to which I must
look upon myself as being related. Thus the reality of the external
sense is necessarily connected with that of the internal, in order
to the possibility of experience in general; that is, I am just as
certainly conscious that there are things external to me related to my
sense as I am that I myself exist as determined in time. But in
order to ascertain to what given intuitions objects, external me,
really correspond, in other words, what intuitions belong to the
external sense and not to imagination, I must have recourse, in
every particular case, to those rules according to which experience in
general (even internal experience) is distinguished from
imagination, and which are always based on the proposition that
there really is an external experience. We may add the remark that the
representation of something permanent in existence, is not the same
thing as the permanent representation; for a representation may be
very variable and changing- as all our representations, even that of
matter, are- and yet refer to something permanent, which must,
therefore, be distinct from all my representations and external to me,
the existence of which is necessarily included in the determination of
my own existence, and with it constitutes one experience- an
experience which would not even be possible internally, if it were not
also at the same time, in part, external. To the question How? we
are no more able to reply, than we are, in general, to think the
stationary in time, the coexistence of which with the variable,
produces the conception of change.
In attempting to render the exposition of my views as intelligible
as possible, I have been compelled to leave out or abridge various
passages which were not essential to the completeness of the work, but
which many readers might consider useful in other respects, and
might be unwilling to miss. This trifling loss, which could not be
avoided without swelling the book beyond due limits, may be
supplied, at the pleasure of the reader, by a comparison with the
first edition, and will, I hope, be more than compensated for by the
greater clearness of the exposition as it now stands.
I have observed, with pleasure and thankfulness, in the pages of
various reviews and treatises, that the spirit of profound and
thorough investigation is not extinct in Germany, though it may have
been overborne and silenced for a time by the fashionable tone of a
licence in thinking, which gives itself the airs of genius, and that
the difficulties which beset the paths of criticism have not prevented
energetic and acute thinkers from making themselves masters of the
science of pure reason to which these paths conduct- a science which
is not popular, but scholastic in its character, and which alone can
hope for a lasting existence or possess an abiding value. To these
deserving men, who so happily combine profundity of view with a talent
for lucid exposition- a talent which I myself am not conscious of
possessing- I leave the task of removing any obscurity which may still
adhere to the statement of my doctrines. For, in this case, the danger
is not that of being refuted, but of being misunderstood. For my own
part, I must henceforward abstain from controversy, although I shall
carefully attend to all suggestions, whether from friends or
adversaries, which may be of use in the future elaboration of the
system of this propaedeutic. As, during these labours, I have advanced
pretty far in years this month I reach my sixty-fourth year- it will
be necessary for me to economize time, if I am to carry out my plan of
elaborating the metaphysics of nature as well as of morals, in
confirmation of the correctness of the principles established in
this Critique of Pure Reason, both speculative and practical; and I
must, therefore, leave the task of clearing up the obscurities of
the present work- inevitable, perhaps, at the outset- as well as,
the defence of the whole, to those deserving men, who have made my
system their own. A philosophical system cannot come forward armed
at all points like a mathematical treatise, and hence it may be
quite possible to take objection to particular passages, while the
organic structure of the system, considered as a unity, has no
danger to apprehend. But few possess the ability, and still fewer
the inclination, to take a comprehensive view of a new system. By
confining the view to particular passages, taking these out of their
connection and comparing them with one another, it is easy to pick out
apparent contradictions, especially in a work written with any freedom
of style. These contradictions place the work in an unfavourable light
in the eyes of those who rely on the judgement of others, but are
easily reconciled by those who have mastered the idea of the whole. If
a theory possesses stability in itself, the action and reaction
which seemed at first to threaten its existence serve only, in the
course of time, to smooth down any superficial roughness or
inequality, and- if men of insight, impartiality, and truly popular
gifts, turn their attention to it- to secure to it, in a short time,
the requisite elegance also.
Konigsberg, April 1787.
