logical； whereas it is plainly transcendental； and concerns not merely
the clearness or obscurity； but the content and origin of both。 For
the faculty of sensibility not only does not present us with an
indistinct and confused cognition of objects as things in
themselves； but； in fact； gives us no knowledge of these at all。 On
the contrary； so soon as we abstract in thought our own subjective
nature； the object represented； with the properties ascribed to it
by sensuous intuition； entirely disappears； because it was only this
subjective nature that determined the form of the object as a
phenomenon。
In phenomena； we monly； indeed； distinguish that which
essentially belongs to the intuition of them； and is valid for the
sensuous faculty of every human being； from that which belongs to
the same intuition accidentally； as valid not for the sensuous faculty
in general； but for a particular state or organization of this or that
sense。 Accordingly； we are accustomed to say that the former is a
cognition which represents the object itself； whilst the latter
presents only a particular appearance or phenomenon thereof。 This
distinction； however； is only empirical。 If we stop here （as is
usual）； and do not regard the empirical intuition as itself a mere
phenomenon （as we ought to do）； in which nothing that can appertain to
a thing in itself is to be found； our transcendental distinction is
lost； and we believe that we cognize objects as things in
themselves； although in the whole range of the sensuous world；
investigate the nature of its objects as profoundly as we may； we have
to do with nothing but phenomena。 Thus； we call the rainbow a mere
appearance of phenomenon in a sunny shower； and the rain； the
reality or thing in itself； and this is right enough； if we understand
the latter conception in a merely physical sense； that is； as that
which in universal experience； and under whatever conditions of
sensuous perception； is known in intuition to be so and so determined；
and not otherwise。 But if we consider this empirical datum
generally； and inquire； without reference to its accordance with all
our senses； whether there can be discovered in it aught which
represents an object as a thing in itself （the raindrops of course are
not such； for they are； as phenomena； empirical objects）； the question
of the relation of the representation to the object is transcendental；
and not only are the raindrops mere phenomena； but even their circular
form； nay； the space itself through which they fall； is nothing in
itself； but both are mere modifications or fundamental dispositions of
our sensuous intuition； whilst the transcendental object remains for
us utterly unknown。
The second important concern of our aesthetic is that it does not
obtain favour merely as a plausible hypothesis； but possess as
undoubted a character of certainty as can be demanded of any theory
which is to serve for an organon。 In order fully to convince the
reader of this certainty； we shall select a case which will serve to
make its validity apparent； and also to illustrate what has been
said in SS 3。
Suppose； then； that space and time are in themselves objective；
and conditions of the… possibility of objects as things in themselves。
In the first place； it is evident that both present us； with very many
apodeictic and synthetic propositions a priori； but especially
space… and for this reason we shall prefer it for investigation at
present。 As the propositions of geometry are cognized synthetically
a priori； and with apodeictic certainty； I inquire： Whence do you
obtain propositions of this kind； and on what basis does the
understanding rest； in order to arrive at such absolutely necessary
and universally valid truths？
There is no other way than through intuitions or conceptions； as
such； and these are given either a priori or a posteriori。 The latter；
namely； empirical conceptions； together with the empirical intuition
on which they are founded； cannot afford any synthetical
proposition； except such as is itself also empirical； that is； a
proposition of experience。 But an empirical proposition cannot possess
the qualities of necessity and absolute universality； which；
nevertheless； are the characteristics of all geometrical propositions。
As to the first and only means to arrive at such cognitions； namely；
through mere conceptions or intuitions a priori； it is quite clear
that from mere conceptions no synthetical cognitions； but only
analytical ones； can be obtained。 Take； for example； the
proposition： 〃Two straight lines cannot enclose a space； and with
these alone no figure is possible；〃 and try to deduce it from the
conception of a straight line and the number two； or take the
proposition： 〃It is possible to construct a figure with three straight
lines；〃 and endeavour； in like manner； to deduce it from the mere
conception of a straight line and the number three。 All your
endeavours are in vain； and you find yourself forced to have
recourse to intuition； as； in fact； geometry always does。 You
therefore give yourself an object in intuition。 But of what kind is
this intuition？ Is it a pure a priori； or is it an empirical
intuition？ If the latter； then neither an universally valid； much less
an apodeictic proposition can arise from it； for experience never
can give us any such proposition。 You must； therefore； give yourself
an object a priori in intuition； and upon that ground your synthetical
proposition。 Now if there did not exist within you a faculty of
intuition a priori； if this subjective condition were not in respect
to its form also the universal condition a priori under which alone
the object of this external intuition is itself possible； if the
object （that is； the triangle） were something in itself； without
relation to you the subject； how could you affirm that that which lies
necessarily in your subjective conditions in order to construct a
triangle； must also necessarily belong to the triangle in itself？
For to your conceptions of three lines； you could not add anything new
（that is； the figure）； which； therefore； must necessarily be found
in the object； because the object is given before your cognition；
and not by means of it。 If； therefore； space （and time also） were
not a mere form of your intuition； which contains conditions a priori；
under which alone things can bee external objects for you； and
without which subjective conditions the objects are in themselves
nothing； you could not construct any synthetical proposition
whatsoever regarding external objects。 It is therefore not merely
possible or probable； but indubitably certain； that space and time； as
the necessary conditions of all our external and internal
experience； are merely subjective conditions of all our intuitions； in
relation to which all objects are therefore mere phenomena； and not
things in themselves； presented to us in this particular manner。 And
for this reason； in respect to the form of phenomena； much may be said
a priori； whilst of the thing in itself； which may lie at the
foundation of these phenomena； it is impossible to say anything。
II。 In confirmation of this theory of the ideality of the external
as well as internal sense； consequently of all objects of sense； as
mere phenomena； we may especially remark that all in our cognition
that belongs to intuition contains nothing more than mere relations。
（The feelings of pain and pleasure； and the will； which are not
cognitions； are excepted。） The relations； to wit； of place in an
intuition （extension）； change of place （motion）； and laws according to
which this change is determined （moving forces）。 That； however；
which is present in this or that place； or any operation going on；
or result taking place in the things themselves； with the exception of
change of place； is not given to us by intuition。 Now by means of mere
relations； a thing cannot be known in itself； and it may therefore
be fairly concluded； that； as through the external sense nothing but
mere representations of relations are given us； the said external
sense in its representation can contain only the relation of the
object to the subject； but not the essential nature of the object as a
thing in itself。
The same is the case with the internal intuition； not only
because； in the internal intuition； the representation of the external
senses constitutes the material with which the mind is occupied； but
because time； in which we place； and which itself antecedes the
consciousness of； these representations in experience； and which； as
the formal condition of the mode according to which objects are placed
in the mind； lies at the foundation of them； contains relations of the
successive； the coexistent； and of that which always must be
coexistent with succession； the permanent。 Now that which； as
representation； can antecede every exercise of thought （of an object）；
is intuition； and when it contains nothing but relations； it is the
form of the intuition； which； as it presents us with no
representation； except in so far as something is placed in the mind；
can be nothing else than the mode in which the mind is affected by its
own activity； to wit… i