These Prolegomena are destined for the use, not of pupils, but of
future teachers, and even the latter should not expect that they will
be serviceable for the systematic exposition of a ready-made science,
but merely for the discovery of the science itself.
There are scholarly men, to whom the history of philosophy (both
ancient and modern) is philosophy itself; for these the present
Prolegomena are not written. They must wait till those who endeavor to
draw from the fountain of reason itself have completed their work; it
will then be the historian's turn to inform the world of what has been
done. Unfortunately, nothing can be said, which in their opinion has
not been said before, and truly the same prophecy applies to all
future time; for since the human reason has for many centuries
speculated upon innumerable objects in various ways, it is hardly to
be expected that we should not be able to discover analogies for every
new idea among the old sayings of past ages.
My object is to persuade all those who think Metaphysics worth
studying, that it is absolutely necessary to pause a moment, and,
neglecting all that has been done, to propose first the preliminary
question, ‘Whether such a thing as metaphysics be at all
possible?’
If it be a science, how comes it that it cannot, like other sciences,
obtain universal and permanent recognition? If not, how can it
maintain its pretensions, and keep the human mind in suspense with
hopes, never ceasing, yet never fulfilled? Whether then we demonstrate
our knowledge or our ignorance in this field, we must come once for
all to a definite conclusion respecting the nature of this so-called
science, which cannot possibly remain on its present footing. It seems
almost ridiculous, while every other science is continually advancing,
that in this, which pretends to be Wisdom incarnate, for whose oracle
every one inquires, we should constantly move round the same spot,
without gaining a single step. And so its followers having melted
away, we do not find men confident of their ability to shine in other
sciences venturing their reputation here, where everybody, however
ignorant in other matters, may deliver a final verdict, as in this
domain there is as yet no standard weight and measure to distinguish
sound knowledge from shallow talk.
After all it is nothing extraordinary in the elaboration of a science,
when men begin to wonder how far it has advanced, that the question
should at last occur, whether and how such a science is possible?
Human reason so delights in constructions, that it has several times
built up a tower, and then razed it to examine the nature of the
foundation. It is never too late to become wise; but if the change
comes late, there is always more difficulty in starting a reform.
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 opposition from all sides. Some, in the proud
consciousness of their possessions, which are ancient, and therefore
considered 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 fully persuaded, that it cannot exist unless the demands
here stated on which its possibility depends, be satisfied; and, as
this has never been done, that there is, as yet, no such thing as
Metaphysics. But as it can never cease to be in demand,{5}—since the
interests of common sense are intimately interwoven with it, he must
confess that a radical reform, or rather a new birth of the science
after an original plan, are unavoidable, however men may struggle
against it for a while.
===================================
{5} Says Horace:
"Rusticus expectat, dum defluat amnis, at ille
Labitur et labetur in omne volubilis aevum;"
"A rustic fellow waiteth on the shore
For the river to flow away,
But the river flows, and flows on as before,
And it flows forever and aye."
===================================
Since the Essays of Locke and Leibnitz, or rather since the origin of
metaphysics so far as we know its history, nothing has ever happened
which was more decisive to its fate than the attack made upon it by
David Hume. He threw no light on this species of knowledge, but he
certainly struck a spark from which light might have been obtained,
had it caught some inflammable substance and had its smouldering fire
been carefully nursed and developed.
Hume started from a single but important concept in Metaphysics, viz.,
that of Cause and Effect (including its derivatives force and action,
etc.). He challenges reason, which pretends to have given birth to
this idea from herself, to answer him by what right she thinks
anything to be so constituted, that if that thing be posited,
something else also must necessarily be posited; for this is the
meaning of the concept of cause. He demonstrated irrefutably that it
was perfectly impossible for reason to think a priori and by means of
concepts a combination involving 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 with reference
to this concept, which she erroneously considered as one of her
children, whereas in reality it was nothing but a bastard of
imagination, impregnated by experience, which subsumed certain
representations under the Law of Association, and mistook the
subjective necessity of habit for an objective necessity arising from
insight. Hence he inferred that reason had no power to think such
combinations, even generally, because her concepts would then be
purely fictitious, and all her pretended 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 metaphysics at all.{6}
===================================
{6} Nevertheless Hume called this very destructive science metaphysics
and attached to it great value. Metaphysics and morals [he declares in
the fourth part of his Essays] are the most important branches of
science; mathematics and physics are not nearly so important. But the
acute man merely regarded the negative use arising from the moderation
of extravagant claims of speculative reason, and the complete
settlement of the many endless and troublesome controversies that
mislead mankind. He overlooked the positive injury which results, if
reason be deprived of its most important prospects, which can alone
supply to the will the highest aim for all its endeavor.
===================================
However hasty and mistaken Hume's conclusion may appear, it was at
least founded upon investigation, and this investigation deserved the
concentrated attention of the brighter spirits of his day as well as
determined efforts on their part to discover, if possible, a happier
solution of the problem in the sense proposed by him, all of which
would have speedily resulted in a complete reform of the science.
But Hume suffered the usual misfortune of metaphysicians, of not being
understood. It is positively painful to see how utterly his opponents,
Reid, Oswald, Beattie, and lastly Priestley, missed the point of the
problem; for while they were ever taking for granted that which he
doubted, and demonstrating with zeal and often with impudence that
which he never thought of doubting, they so misconstrued his valuable
suggestion that everything remained in its old condition, as if
nothing had happened.
The question was not whether the concept of cause was right, useful,
and even indispensable for our knowledge of nature, for this Hume had
never doubted; but whether that concept could be thought by reason a
priori, and consequently whether it possessed an inner truth,
independent of all experience, implying a wider application than
merely to the objects of experience. This was Hume's problem. It was a
question concerning the origin, not concerning the indispensable need
of the concept. Were the former decided, the conditions of the use and
the sphere of its valid application would have been determined as a
matter of course.
But to satisfy the conditions of the problem, the opponents of the
great thinker should have penetrated very deeply into the nature of
reason, so far as it is concerned with pure thinking,—a task which
did not suit them. They found a more convenient method of being
defiant without any insight, viz., the appeal to common sense. 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 no rational justification can be advanced. 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 superficial ranter can safely enter the lists
with the most thorough 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 charlatan glories and confides in it? I should think that Hume
might fairly have laid as much claim to common sense as Beattie, and
in addition to a critical reason (such as the latter did not possess),
which keeps common sense in check and prevents it from speculating,
or, if speculations are under discussion, restrains the desire to
decide because it cannot satisfy itself concerning its own arguments.
By this means alone can common sense remain sound. Chisels and hammers
may suffice to work a piece of wood, but for steel-engraving we
require an engraver's needle. 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 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 connexion of
cause and effect was by no means the only idea by which the
understanding thinks the connexion of things a priori, but rather that
metaphysics consists altogether of such connexions. 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 had 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 ever,
he did not suspect such a formal science, but ran his ship ashore, for
safety's sake, landing on scepticism, 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 our 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 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, to which I had devoted myself so long; in
truth, it required no little constancy, and even self-denial, to
postpone the sweets of an immediate success to the prospect of a
slower, but more lasting, reputation.
Making plans is often the occupation of an opulent 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 critique of pure
reason than mere conjectures, if this plan is to be other than the
usual declamations 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 domain of 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 critique that it is never trustworthy except it be
perfectly complete, down to the smallest elements of pure reason. In
the sphere of this faculty you can determine either everything or
nothing.
But although a mere sketch, preceding the Critique of Pure Reason,
would be unintelligible, unreliable, and useless, it is all the more
useful as a 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.
After the completion of the work I offer here such a plan which is
sketched out after an analytical method, while the work itself had to
be executed in the synthetical style, in order that the science may
present all its articulations, as the structure of a peculiar
cognitive faculty, in their natural combination. But should any reader
find this plan, which I publish as the Prolegomena to any future
Metaphysics, still obscure, let him consider that not every one is
bound to study Metaphysics, that many minds will succeed very well, in
the exact and even in deep sciences, more closely allied to practical
experience,{7} while they cannot succeed in investigations dealing
exclusively with abstract concepts. In such cases men should apply
their talents to other subjects. But he who undertakes to judge, or
still more, to construct, a system of Metaphysics, must satisfy the
demands here made, either by adopting my solution, or by thoroughly
refuting it, and substituting another. To evade it is impossible.
===================================
{7} The term Anschauung here used means sense-perception. It is that
which is given to the senses and apprehended immediately, as an object
is seen by merely looking at it. The translation intuition, though
etymologically correct, is misleading. In the present passage the term
is not used in its technical significance but means "practical
experience."—Ed.
===================================
In conclusion, let it be remembered that this much-abused obscurity
(frequently serving as a mere pretext under which people hide their
own indolence or dullness) has its uses, since all who in other
sciences observe a judicious silence, speak authoritatively in
metaphysics and make bold decisions, 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 praesepibus arcent."
"Bees are defending their hives against drones, those indolent
creatures."