SS 19.
The foregoing proposition is of the utmost importance, for it
determines the limits of the exercise of the pure conceptions of the
understanding in regard to objects, just as transcendental æsthetic
determined the limits of the exercise of the pure form of our sensuous
intuition. Space and time, as conditions of the possibility of the
presentation of objects to us, are valid no further than for objects
of sense, consequently, only for experience. Beyond these limits
they represent to us nothing, for they belong only to sense, and
have no reality apart from it. The pure conceptions of the
understanding are free from this limitation, and extend to objects
of intuition in general, be the intuition like or unlike to ours,
provided only it be sensuous, and not intellectual. But this extension
of conceptions beyond the range of our intuition is of no advantage;
for they are then mere empty conceptions of objects, as to the
possibility or impossibility of the existence of which they furnish us
with no means of discovery. They are mere forms of thought, without
objective reality, because we have no intuition to which the
synthetical unity of apperception, which alone the categories contain,
could be applied, for the purpose of determining an object. Our
sensuous and empirical intuition can alone give them significance
and meaning.
If, then, we suppose an object of a non—sensuous intuition to be
given we can in that case represent it by all those predicates which
are implied in the presupposition that nothing appertaining to
sensuous intuition belongs to it; for example, that it is not
extended, or in space; that its duration is not time; that in it no
change (the effect of the determinations in time) is to be met with,
and so on. But it is no proper knowledge if I merely indicate what the
intuition of the object is not, without being able to say what is
contained in it, for I have not shown the possibility of an object
to which my pure conception of understanding could be applicable,
because I have not been able to furnish any intuition corresponding to
it, but am only able to say that our intuition is not valid for it.
But the most important point is this, that to a something of
this kind
not one category can be found applicable. Take, for example, the
conception of substance, that is, something that can exist as subject,
but never as mere predicate; in regard to this conception I am quite
ignorant whether there can really be anything to correspond to such
a determination of thought, if empirical intuition did not afford me
the occasion for its application. But of this more in the sequel.