ul as a simple, immaterial
substance which survives the death of the body, cannot be proved, yet we
need not, for that reason, regard them as erroneous, for the opposite is as
little susceptible of demonstration. The whole question belongs not in the
forum of knowledge, but in the forum of faith, and that which we gain by
the proof that nothing can be determined concerning it by theoretical
reasoning (viz., assurance against materialistic objections) is far more
valuable than what we lose.

[Footnote 1: The rational concept of the soul as a simple, independent
intelligence does not signify an actual being, but only expresses certain
principles of systematic unity in the explanation of psychical phenomena,
viz., "To regard all determinations as existing in one subject, all powers,
as far as possible, as derived from, one fundamental power, all change
as belonging to the states of one and the same permanent being, and
to represent all phenomena in space as totally distinct from acts of
thought."]

(2) _The Antinomies of Rational Cosmology_. If in its endeavor to spin
metaphysical knowledge concerning the nature of the spirit and the
existence of the soul after death out of the concept of the thinking ego
the reason falls into the snare of an ambiguous _terminus medius_, the
difficulties which frustrate its attempts to use the Idea of the world
in the extension of its knowledge _a priori_ are of quite a different
character. Here the formal correctness of the method of inference is not
open to attack. It may be proved with absolute strictness (and in the
apagogical or indirect form, from the impossibility of the contrary) that
the world has a beginning in time, and also that it is _limited_ in space;
that every compound substance consists of _simple_ parts; that, besides the
causality according to the laws of nature, there is a causality through
_freedom_, and that an _absolutely necessary Being_ exists, either as a
part of the world or as the cause of it. But the contrary may be proved
with equal stringency (and indirectly, as before): The world is infinite in
space and time; there is nothing simple in the world; there is no freedom,
but everything in the world takes place entirely according to the laws of
nature; and there exists no absolutely necessary Being either within the
world or without it. This is the famous doctrine of the conflict of the
four cosmological theses and antitheses or of the Antinomy of Pure Reason,