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 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 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