bility; all other sensuous concepts, even motion and change,
presuppose perception; the movable in space and the succession of
properties in an existing thing are empirical data.

In confirmation of the theory that all objects of the senses are mere
phenomena, the fact is adduced that (with the exception of the will and the
feelings, which are not cognitions) nothing is given us through the senses
but representations of relations, while a thing in itself cannot be known
by mere relations. The phenomenon is a sum total of mere relations. In
regard to matter we know only extension, motion, and the laws of this
motion or forces (attraction, repulsion, impenetrability), but all these
are merely relations of the thing to something, else, that is, external
relations. Where is the inner side which underlies this exterior, and
which belongs to the object in itself? This is never to be found in the
phenomenon, and no matter how far the observation and analysis of nature
may advance (a work with unlimited horizons!) they reach nothing but
portions of space occupied by matter and effects which matter exercises,
that is, nothing beyond that which is comparatively internal, and which,
in its turn, consists of external relations. The absolutely inner side
of matter is a mere fancy; and if the complaint that the "inner side" of
things is concealed from us is to mean that we do not comprehend what
the things which appear to us may be in themselves, it is unjust and
irrational, for it demands that we should be able to intuit without
senses, in other words, that we should be other than men. The transcendent
questions concerning the noumenon of things are unanswerable; we know
ourselves, even, only as phenomena! A phenomenon consists in nothing but
the relation of something in general to the senses.

It is indubitable _that_ something corresponds to phenomena, which,
by affecting our sensibility, occasions sensations in us, and thereby
phenomena. The very word, the very concept, "phenomenon", indicates a
relation to something which is not phenomenon, to an object not dependent
on the sensibility. _What_ this may be continues hidden from us, for
knowledge is impossible without intuition. Things in themselves are
unknowable. Nevertheless the idea (it must be confessed, the entirely empty
idea) of this "transcendental object", as an indeterminate somewhat = _x_
which underlies phenomena, is not only allowable, but, as a limiting
concept, una