Let it be supposed that a composite thing (as substance) consists of
simple parts. Inasmuch as all external relation, consequently all
composition of substances, is possible only in space; the space,
occupied by that which is composite, must consist of the same number of
parts as is contained in the composite. But space does not consist of
simple parts, but of spaces. Therefore, every part of the composite
must occupy a space. But the absolutely primary parts of what is
composite are simple. It follows that what is simple occupies a space.
Now, as everything real that occupies a space, contains a manifold the
parts of which are external to each other, and is consequently
composite—and a real composite, not of accidents (for these cannot
exist external to each other apart from substance), but of
substances—it follows that the simple must be a substantial composite,
which is self-contradictory.
The second proposition of the antithesis—that there exists in the world
nothing that is simple—is here equivalent to the following: The
existence of the absolutely simple cannot be demonstrated from any
experience or perception either external or internal; and the
absolutely simple is a mere idea, the objective reality of which cannot
be demonstrated in any possible experience; it is consequently, in the
exposition of phenomena, without application and object. For, let us
take for granted that an object may be found in experience for this
transcendental idea; the empirical intuition of such an object must
then be recognized to contain absolutely no manifold with its parts
external to each other, and connected into unity. Now, as we cannot
reason from the non-consciousness of such a manifold to the
impossibility of its existence in the intuition of an object, and as
the proof of this impossibility is necessary for the establishment and
proof of absolute simplicity; it follows that this simplicity cannot be
inferred from any perception whatever. As, therefore, an absolutely
simple object cannot be given in any experience, and the world of sense
must be considered as the sum total of all possible experiences:
nothing simple exists in the world.
This second proposition in the antithesis has a more extended aim than
the first. The first merely banishes the simple from the intuition of
the composite; while the second drives it entirely out of nature. Hence
we were unable to demonstrate it from the conception of a given object
of external intuition (of the composite), but we were obliged to prove
it from the relation of a given object to a possible experience in
general.
OBSERVATIONS ON THE SECOND ANTINOMY. THESIS.