THE CRITIQUE OF PURE REASON

by Immanuel Kant

translated by J. M. D. Meiklejohn



PREFACE TO THE FIRST EDITION, 1781

Human reason, in one sphere of its cognition, is called upon to
consider questions, which it cannot decline, as they are presented
by its own nature, but which it cannot answer, as they transcend every
faculty of the mind.

It falls into this difficulty without any fault of its own. It
begins with principles, which cannot be dispensed with in the field
of experience, and the truth and sufficiency of which are, at the same
time, insured by experience. With these principles it rises, in
obedience to the laws of its own nature, to ever higher and more
remote conditions. But it quickly discovers that, in this way, its
labours must remain ever incomplete, because new questions never cease
to present themselves; and thus it finds itself compelled to have
recourse to principles which transcend the region of experience, while
they are regarded by common sense without distrust. It thus falls into
confusion and contradictions, from which it conjectures the presence
of latent errors, which, however, it is unable to discover, because
the principles it employs, transcending the limits of experience,
cannot be tested by that criterion. The arena of these endless
contests is called Metaphysic.

Time was, when she was the queen of all the sciences; and, if we
take the will for the deed, she certainly deserves, so far as
regards the high importance of her object-matter, this title of
honour. Now, it is the fashion of the time to heap contempt and
scorn upon her; and the matron mourns, forlorn and forsaken, like
Hecuba:

    Modo maxima rerum,
    Tot generis, natisque potens...
    Nunc trahor exul, inops.
            -- Ovid, Metamorphoses. xiii

At first, her government, under the administration of the
dogmatists, was an absolute despotism. But, as the legislative
continued to show traces of the ancient barbaric rule, her empire
gradually broke up, and intestine wars introduced the reign of
anarchy; while the sceptics, like nomadic tribes, who hate a permanent
habitation and settled mode of living, attacked from time to time
those who had organized themselves into civil communities. But their
number was, very happily, small; and thus they could not entirely
put a stop to the exertions of those who persisted in raising new
edifices, although on no settled or uniform plan. In recent times
the hope dawned upon us of seeing those disputes settled, and the
legitimacy of her claims established by a kind of physiology of the
human understanding--that of the celebrated Locke. But it was found
that--although it was affirmed that this so-called queen could not
refer her descent to any higher source than that of common experience,
a circumstance which necessarily brought suspicion on her claims--as
this genealogy was incorrect, she persisted in the advancement of
her claims to sovereignty. Thus metaphysics necessarily fell back into
the antiquated and rotten constitution of dogmatism, and again
became obnoxious to the contempt from which efforts had been made to
save it. At present, as all methods, according to the general
persuasion, have been tried in vain, there reigns nought but weariness
and complete indifferentism--the mother of chaos and night in the
scientific world, but at the same time the source of, or at least
the prelude to, the re-creation and reinstallation of a science,
when it has fallen into confusion, obscurity, and disuse from ill
directed effort.

For it is in reality vain to profess indifference in regard to
such inquiries, the object of which cannot be indifferent to humanity.
Besides, these pretended indifferentists, however much they may try
to disguise themselves by the assumption of a popular style and by
changes on the language of the schools, unavoidably fall into
metaphysical declarations and propositions, which they profess to
regard with so much contempt. At the same time, this indifference,
which has arisen in the world of science, and which relates to that
kind of knowledge which we should wish to see destroyed the last, is
a phenomenon that well deserves our attention and reflection. It is
plainly not the effect of the levity, but of the matured judgement*
of the age, which refuses to be any longer entertained with illusory
knowledge, It is, in fact, a call to reason, again to undertake the
most laborious of all tasks--that of self-examination, and to
establish a tribunal, which may secure it in its well-grounded claims,
while it pronounces against all baseless assumptions and
pretensions, not in an arbitrary manner, but according to its own
eternal and unchangeable laws. This tribunal is nothing less than
the critical investigation of pure reason.

[*Footnote: We very often hear complaints of the shallowness of the
present age, and of the decay of profound science. But I do not think
that those which rest upon a secure foundation, such as mathematics,
physical science, etc., in the least deserve this reproach, but that
they rather maintain their ancient fame, and in the latter case,
indeed, far surpass it. The same would be the case with the other
kinds of cognition, if their principles were but firmly established.
In the absence of this security, indifference, doubt, and finally,
severe criticism are rather signs of a profound habit of thought.
Our age is the age of criticism, to which everything must be
subjected. The sacredness of religion, and the authority of
legislation, are by many regarded as grounds of exemption from the
examination of this tribunal. But, if they on they are exempted,
they become the subjects of just suspicion, and cannot lay claim to
sincere respect, which reason accords only to that which has stood
the test of a free and public examination.]

I do not mean by this a criticism of books and systems, but a
critical inquiry into the faculty of reason, with reference to the
cognitions to which it strives to attain without the aid of
experience; in other words, the solution of the question regarding
the possibility or impossibility of metaphysics, and the determination
of the origin, as well as of the extent and limits of this science.
All this must be done on the basis of principles.

This path--the only one now remaining--has been entered upon by
me; and I flatter myself that I have, in this way, discovered the
cause of--and consequently the mode of removing--all the errors
which have hitherto set reason at variance with itself, in the
sphere of non-empirical thought. I have not returned an evasive answer
to the questions of reason, by alleging the inability and limitation
of the faculties of the mind; I have, on the contrary, examined them
completely in the light of principles, and, after having discovered
the cause of the doubts and contradictions into which reason fell,
have solved them to its perfect satisfaction. It is true, these
questions have not been solved as dogmatism, in its vain fancies and
desires, had expected; for it can only be satisfied by the exercise
of magical arts, and of these I have no knowledge. But neither do these
come within the compass of our mental powers; and it was the duty of
philosophy to destroy the illusions which had their origin in
misconceptions, whatever darling hopes and valued expectations may
be ruined by its explanations. My chief aim in this work has been
thoroughness; and I make bold to say that there is not a single
metaphysical problem that does not find its solution, or at least
the key to its solution, here. Pure reason is a perfect unity; and
therefore, if the  principle presented by it prove to be insufficient
for the solution of even a single one of those questions to which
the very nature of reason gives birth, we must reject it, as we could
not be perfectly certain of its sufficiency in the case of the others.

While I say this, I think I see upon the countenance of the reader
signs of dissatisfaction mingled with contempt, when he hears
declarations which sound so boastful and extravagant; and yet they
are beyond comparison more moderate than those advanced by the commonest
author of the commonest philosophical programme, in which the
dogmatist professes to demonstrate the simple nature of the soul, or
the necessity of a primal being. Such a dogmatist promises to extend
human knowledge beyond the limits of possible experience; while I
humbly confess that this is completely beyond my power. Instead of
any such attempt, I confine myself to the examination of reason alone
and its pure thought; and I do not need to seek far for the
sum-total of its cognition, because it has its seat in my own mind.
Besides, common logic presents me with a complete and systematic
catalogue of all the simple operations of reason; and it is my task
to answer the question how far reason can go, without the material
presented and the aid furnished by experience.

So much for the completeness and thoroughness necessary in the
execution of the present task. The aims set before us are not
arbitrarily proposed, but are imposed upon us by the nature of
cognition itself.

The above remarks relate to the matter of our critical inquiry. As
regards the form, there are two indispensable conditions, which any
one who undertakes so difficult a task as that of a critique of pure
reason, is bound to fulfil. These conditions are certitude and
clearness.

As regards certitude, I have fully convinced myself that, in this
sphere of thought, opinion is perfectly inadmissible, and that
everything which bears the least semblance of an hypothesis must be
excluded, as of no value in such discussions. For it is a necessary
condition of every cognition that is to be established upon a priori
grounds that it shall be held to be absolutely necessary; much more
is this the case with an attempt to determine all pure a priori
cognition, and to furnish the standard--and consequently an example--
of all apodeictic (philosophical) certitude. Whether I have
succeeded in what I professed to do, it is for the reader to
determine; it is the author's business merely to adduce grounds and
reasons, without determining what influence these ought to have on
the mind of his judges. But, lest anything he may have said may become
the innocent cause of doubt in their minds, or tend to weaken the effect
which his arguments might otherwise produce--he may be allowed to
point out those passages which may occasion mistrust or difficulty,
although these do not concern the main purpose of the present work.
He does this solely with the view of removing from the mind of the
reader any doubts which might affect his judgement of the work as a
whole, and in regard to its ultimate aim.

I know no investigations more necessary for a full insight into
the nature of the faculty which we call understanding, and at the same
time for the determination of the rules and limits of its use, than
those undertaken in the second chapter of the "Transcendental
Analytic," under the title of "Deduction of the Pure Conceptions of
the Understanding"; and they have also cost me by far the greatest
labour--labour which, I hope, will not remain uncompensated. The
view there taken, which goes somewhat deeply into the subject, has
two sides, The one relates to the objects of the pure understanding,
and is intended to demonstrate and to render comprehensible the
objective validity of its a priori conceptions; and it forms for
this reason an essential part of the Critique. The other considers
the pure understanding itself, its possibility and its powers of
cognition--that is, from a subjective point of view; and, although
this exposition is of great importance, it does not belong essentially
to the main purpose of the work, because the grand question is what
and how much can reason and understanding, apart from experience,
cognize, and not, how is the faculty of thought itself possible? As
the latter is an, inquiry into the cause of a given effect, and has
thus in it some semblance of an hypothesis (although, as I shall
show on another occasion, this is really not the fact), it would
seem that, in the present instance, I had allowed myself to enounce
a mere opinion, and that the reader must therefore be at liberty to
hold a different opinion. But I beg to remind him that, if my
subjective deduction does not produce in his mind the conviction of
its certitude at which I aimed, the objective deduction, with which
alone the present work is properly concerned, is in every respect
satisfactory.