reality as representations； belong only to the genus phenomenon； which
has always two aspects； the one； the object considered as a thing in
itself； without regard to the mode of intuiting it； and the nature
of which remains for this very reason problematical； the other； the
form of our intuition of the object； which must be sought not in the
object as a thing in itself； but in the subject to which it appears…
which form of intuition nevertheless belongs really and necessarily to
the phenomenal object。
Time and space are； therefore； two sources of knowledge； from which；
a priori； various synthetical cognitions can be drawn。 Of this we find
a striking example in the cognitions of space and its relations； which
form the foundation of pure mathematics。 They are the two pure forms
of all intuitions； and thereby make synthetical propositions a
priori possible。 But these sources of knowledge being merely
conditions of our sensibility； do therefore； and as such； strictly
determine their own range and purpose； in that they do not and
cannot present objects as things in themselves； but are applicable
to them solely in so far as they are considered as sensuous phenomena。
The sphere of phenomena is the only sphere of their validity； and if
we venture out of this； no further objective use can be made of
them。 For the rest； this formal reality of time and space leaves the
validity of our empirical knowledge unshaken； for our certainty in
that respect is equally firm； whether these forms necessarily inhere
in the things themselves； or only in our intuitions of them。 On the
other hand； those who maintain the absolute reality of time and space；
whether as essentially subsisting； or only inhering； as modifications；
in things； must find themselves at utter variance with the
principles of experience itself。 For； if they decide for the first
view； and make space and time into substances； this being the side
taken by mathematical natural philosophers； they must admit two
self…subsisting nonentities； infinite and eternal； which exist （yet
without there being anything real） for the purpose of containing in
themselves everything that is real。 If they adopt the second view of
inherence； which is preferred by some metaphysical natural
philosophers； and regard space and time as relations （contiguity in
space or succession in time）； abstracted from experience； though
represented confusedly in this state of separation； they find
themselves in that case necessitated to deny the validity of
mathematical doctrines a priori in reference to real things （for
example； in space）… at all events their apodeictic certainty。 For such
certainty cannot be found in an a posteriori proposition； and the
conceptions a priori of space and time are； according to this opinion；
mere creations of the imagination； having their source really in
experience； inasmuch as； out of relations abstracted from
experience； imagination has made up something which contains；
indeed； general statements of these relations； yet of which no
application can be made without the restrictions attached thereto by
nature。 The former of these parties gains this advantage； that they
keep the sphere of phenomena free for mathematical science。 On the
other hand； these very conditions （space and time） embarrass them
greatly； when the understanding endeavours to pass the limits of
that sphere。 The latter has； indeed； this advantage； that the
representations of space and time do not e in their way when they
wish to judge of objects； not as phenomena； but merely in their
relation to the understanding。 Devoid； however； of a true and
objectively valid a priori intuition； they can neither furnish any
basis for the possibility of mathematical cognitions a priori； nor
bring the propositions of experience into necessary accordance with
those of mathematics。 In our theory of the true nature of these two
original forms of the sensibility； both difficulties are surmounted。
In conclusion； that transcendental aesthetic cannot contain any more
than these two elements… space and time； is sufficiently obvious
from the fact that all other conceptions appertaining to
sensibility； even that of motion； which unites in itself both
elements； presuppose something empirical。 Motion； for example；
presupposes the perception of something movable。 But space
considered in itself contains nothing movable； consequently motion
must be something which is found in space only through experience…
in other words； an empirical datum。 In like manner； transcendental
aesthetic cannot number the conception of change among its data a
priori； for time itself does not change； but only something which is
in time。 To acquire the conception of change； therefore； the
perception of some existing object and of the succession of its
determinations； in one word； experience； is necessary。
SS 9 General Remarks on Transcendental Aesthetic。
I。 In order to prevent any misunderstanding； it will be requisite；
in the first place； to recapitulate； as clearly as possible； what
our opinion is with respect to the fundamental nature of our
sensuous cognition in general。 We have intended； then； to say that all
our intuition is nothing but the representation of phenomena； that the
things which we intuite； are not in themselves the same as our
representations of them in intuition； nor are their relations in
themselves so constituted as they appear to us； and that if we take
away the subject； or even only the subjective constitution of our
senses in general； then not only the nature and relations of objects
in space and time； but even space and time themselves disappear； and
that these； as phenomena； cannot exist in themselves； but only in
us。 What may be the nature of objects considered as things in
themselves and without reference to the receptivity of our sensibility
is quite unknown to us。 We know nothing more than our mode of
perceiving them； which is peculiar to us； and which； though not of
necessity pertaining to every animated being； is so to the whole human
race。 With this alone we have to do。 Space and time are the pure forms
thereof； sensation the matter。 The former alone can we cognize a
priori； that is； antecedent to all actual perception； and for this
reason such cognition is called pure intuition。 The latter is that
in our cognition which is called cognition a posteriori； that is；
empirical intuition。 The former appertain absolutely and necessarily
to our sensibility； of whatsoever kind our sensations may be； the
latter may be of very diversified character。 Supposing that we
should carry our empirical intuition even to the very highest degree
of clearness； we should not thereby advance one step nearer to a
knowledge of the constitution of objects as things in themselves。
For we could only； at best； arrive at a plete cognition of our
own mode of intuition； that is of our sensibility； and this always
under the conditions originally attaching to the subject； namely；
the conditions of space and time； while the question： 〃What are
objects considered as things in themselves？〃 remains unanswerable even
after the most thorough examination of the phenomenal world。
To say； then； that all our sensibility is nothing but the confused
representation of things containing exclusively that which belongs
to them as things in themselves； and this under an accumulation of
characteristic marks and partial representations which we cannot
distinguish in consciousness； is a falsification of the conception
of sensibility and phenomenization； which renders our whole doctrine
thereof empty and useless。 The difference between a confused and a
clear representation is merely logical and has nothing to do with
content。 No doubt the conception of right； as employed by a sound
understanding； contains all that the most subtle investigation could
unfold from it； although； in the ordinary practical use of the word；
we are not conscious of the manifold representations prised in
the conception。 But we cannot for this reason assert that the ordinary
conception is a sensuous one； containing a mere phenomenon； for
right cannot appear as a phenomenon； but the conception of it lies
in the understanding； and represents a property （the moral property）
of actions； which belongs to them in themselves。 On the other hand；
the representation in intuition of a body contains nothing which could
belong to an object considered as a thing in itself； but merely the
phenomenon or appearance of something； and the mode in which we are
affected by that appearance； and this receptivity of our faculty of
cognition is called sensibility； and remains toto caelo different from
the cognition of an object in itself； even though we should examine
the content of the phenomenon to the very bottom。
It must be admitted that the Leibnitz…Wolfian philosophy has
assigned an entirely erroneous point of view to all investigations
into the nature and origin of our cognitions； inasmuch as it regards
the distinction between the sensuous and the intellectual as merely
logical； whereas it is plainly transcendental； and concerns not merely
the clearness or obscurity； but the content and origin of both