按键盘上方向键 ← 或 → 可快速上下翻页，按键盘上的 Enter 键可回到本书目录页，按键盘上方向键 ↑ 可回到本页顶部！
————未阅读完？加入书签已便下次继续阅读！
being by itself infallible。
Now； that in the sphere of human cognition we have judgements
which are necessary； and in the strictest sense universal；
consequently pure a priori； it will be an easy matter to show。 If we
desire an example from the sciences； we need only take any proposition
in mathematics。 If we cast our eyes upon the monest operations of
the understanding； the proposition； 〃Every change must have a
cause；〃 will amply serve our purpose。 In the latter case； indeed；
the conception of a cause so plainly involves the conception of a
necessity of connection with an effect； and of a strict universality
of the law； that the very notion of a cause would entirely
disappear； were we to derive it； like Hume； from a frequent
association of what happens with that which precedes； and the habit
thence originating of connecting representations… the necessity
inherent in the judgement being therefore merely subjective。
Besides； without seeking for such examples of principles existing a
priori in cognition； we might easily show that such principles are the
indispensable basis of the possibility of experience itself； and
consequently prove their existence a priori。 For whence could our
experience itself acquire certainty； if all the rules on which it
depends were themselves empirical； and consequently fortuitous？ No
one； therefore； can admit the validity of the use of such rules as
first principles。 But； for the present； we may content ourselves
with having established the fact； that we do possess and exercise a
faculty of pure a priori cognition； and； secondly； with having pointed
out the proper tests of such cognition； namely； universality and
necessity。
Not only in judgements； however； but even in conceptions； is an a
priori origin manifest。 For example； if we take away by degrees from
our conceptions of a body all that can be referred to mere sensuous
experience… colour； hardness or softness； weight； even
impenetrability… the body will then vanish； but the space which it
occupied still remains； and this it is utterly impossible to
annihilate in thought。 Again； if we take away； in like manner； from
our empirical conception of any object； corporeal or incorporeal；
all properties which mere experience has taught us to connect with it；
still we cannot think away those through which we cogitate it as
substance； or adhering to substance； although our conception of
substance is more determined than that of an object。 pelled；
therefore； by that necessity with which the conception of substance
forces itself upon us； we must confess that it has its seat in our
faculty of cognition a priori。
III。 Philosophy stands in need of a Science which shall
Determine the Possibility； Principles； and Extent of
Human Knowledge 〃a priori〃
Of far more importance than all that has been above said； is the
consideration that certain of our cognitions rise pletely above the
sphere of all possible experience； and by means of conceptions； to
which there exists in the whole extent of experience no
corresponding object； seem to extend the range of our judgements
beyond its bounds。 And just in this transcendental or supersensible
sphere； where experience affords us neither instruction nor
guidance； lie the investigations of reason； which； on account of their
importance； we consider far preferable to； and as having a far more
elevated aim than； all that the understanding can achieve within the
sphere of sensuous phenomena。 So high a value do we set upon these
investigations； that even at the risk of error； we persist in
following them out； and permit neither doubt nor disregard nor
indifference to restrain us from the pursuit。 These unavoidable
problems of mere pure reason are God； freedom （of will）； and
immortality。 The science which； with all its preliminaries； has for
its especial object the solution of these problems is named
metaphysics… a science which is at the very outset dogmatical； that
is； it confidently takes upon itself the execution of this task
without any previous investigation of the ability or inability of
reason for such an undertaking。
Now the safe ground of experience being thus abandoned； it seems
nevertheless natural that we should hesitate to erect a building
with the cognitions we possess； without knowing whence they e；
and on the strength of principles； the origin of which is
undiscovered。 Instead of thus trying to build without a foundation； it
is rather to be expected that we should long ago have put the
question； how the understanding can arrive at these a priori
cognitions； and what is the extent； validity； and worth which they may
possess？ We say； 〃This is natural enough；〃 meaning by the word
natural； that which is consistent with a just and reasonable way of
thinking； but if we understand by the term； that。 which usually
happens； nothing indeed could be more natural and more
prehensible than that this investigation should be left long
unattempted。 For one part of our pure knowledge； the science of
mathematics； has been long firmly established； and thus leads us to
form flattering expectations with regard to others； though these may
be of quite a different nature。 Besides； when we get beyond the bounds
of experience； we are of course safe from opposition in that
quarter； and the charm of widening the range of our knowledge is so
great that； unless we are brought to a standstill by some evident
contradiction； we hurry on undoubtingly in our course。 This；
however； may be avoided； if we are sufficiently cautious in the
construction of our fictions； which are not the less fictions on
that account。
Mathematical science affords us a brilliant example； how far；
independently of all experience； we may carry our a priori
knowledge。 It is true that the mathematician occupies himself with
objects and cognitions only in so far as they can be represented by
means of intuition。 But this circumstance is easily overlooked；
because the said intuition can itself be given a priori； and therefore
is hardly to be distinguished from a mere pure conception。 Deceived by
such a proof of the power of reason； we can perceive no limits to
the extension of our knowledge。 The light dove cleaving in free flight
the thin air； whose resistance it feels； might imagine that her
movements would be far more free and rapid in airless space。 just in
the same way did Plato； abandoning the world of sense because of the
narrow limits it sets to the understanding； venture upon the wings
of ideas beyond it； into the void space of pure intellect。 He did
not reflect that he made no real progress by all his efforts； for he
met with no resistance which might serve him for a support； as it
were； whereon to rest； and on which he might apply his powers； in
order to let the intellect acquire momentum for its progress。 It is；
indeed； the mon fate of human reason in speculation； to finish
the imposing edifice of thought as rapidly as possible； and then for
the first time to begin to examine whether the foundation is a solid
one or no。 Arrived at this point； all sorts of excuses are sought
after； in order to console us for its want of stability； or ra