from mere concepts, as in metaphysics, where sound common sense,
so called in spite of the inapplicability of the word, has no
right to judge at all.

     I openly 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 in
the conclusions at which he arrived by 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 connection of cause and effect was by no means the only idea
by which the understanding thinks the connection of things a
priori, but rather that metaphysics consists altogether of such
connections. I sought to ascertain their number, and when I had
satisfactorily succeeded in this 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
bad never even occurred to any one else, though no one had
hesitated to use the concepts without investigating the basis of
their objective validity) was the most difficult task ever
undertaken in the service of metaphysics; and the worst was that
metaphysics, such as it then existed, could not assist me in the
least, because this deduction alone can render metaphysics
possible. 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 circumference as well as in
its contents. This was required for metaphysics in order to
construct its system according to a reliable method.

     But I fear that the execution of Hume's problem in its
widest extent (viz., my Critique 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 long-winded. I confess,
however, I did not expect, to hear from philosophers complaints
of want of popularity, entertainment, and facility, when the
existence of a highly prized and indispensable cognition is at
stake, which cannot be established otherwise, than by the
strictest rules of methodic precision. Popularity may follow, but
is inadmissible at the beginning. Yet as regards a certain
obscurity, arising partly from the diffuseness of the plan, owing
to which. the principal points of the investigation are easily
lost sight of, the complaint is just, and I intend to remove it
by the present Prolegomena.

     The first-mentioned work, which discusses the pure faculty
of reason in its whole compass and bounds, will remain the
foundation, to which the Prolegomena, as a preliminary, exercise,
refer; for our critique must first be established as a complete
and perfected science, before we can think of letting Metaphysics
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 taking it out of its former context, and
reducing it to system in a new suit of any fancy pattern under
new titles. Most readers will set out by expecting nothing else
from the Critique; 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 suggestion of Hume's doubts. Yet even he did not
suspect such a formal science, but ran his ship ashore, for
safety's sake, landing on skepticism, there to let it lie and
rot; whereas my object is rather to give it a pilot, who, by
means of safe astronomical 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 in a new science, which is wholly isolated and unique in
its kind, we started with the prejudice that we can judge of
things by means of our previously acquired knowledge, which., is
precisely what has first to be called in question, we should only
fancy we saw everywhere what we had already known,. the
expressions, having a similar sound, only that all would appear
utterly metamorphosed, senseless and unintelligible, because we
should have as a foundation out own notions, made by long habit a
second nature, instead of the author's. But the longwindedness of
the work, so far as it depends on the subject, and not the
exposition, its consequent unavoidable dryness and its scholastic
precision are qualities which can only benefit the science,
though they may discredit the book.

     Few writers are gifted with the subtlety, 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