relations otherwise unknown between ourselves and the infinite
Deity; suppose he were to argue that psychical qualities may be
inherent in a spiritual substance which under certain conditions
becomes incarnated in matter, to wear it as a perishable garment
for a brief season, but presently to cast it off and enter upon
the freedom of a larger existence;--what reply should we be bound
to make, bearing in mind that the possibilities of existence are
in no wise limited by our experience? Obviously we should be
bound to admit that in sound philosophy this conclusion is just
as likely to be true as the other. We should, indeed, warn him
not to call on us to help him to establish it by scientific
arguments; and we should remind him that he must not make illicit
use of his extra-experiential hypotheses by bringing them into
the treatment of scientific questions that lie within the range
of experience. In science, for example, we make no use of the
conception of a "spiritual substance" (or of a "material
substance" either), because we can get along sufficiently well by
dealing solely with qualities. But with this general
understanding we should feel bound to concede the impregnableness
of his main position.

I have supposed this theory only as an illustration, not as a
theory which I am prepared to adopt. My present purpose is not to
treat as an advocate the question of a future life, but to
endeavour to point out what conditions should be observed in
treating the question philosophically. It seems to me that a
great deal is gained when we have distinctly set before us what
are the peculiar conditions of proof in the case of such
transcendental questions. We have gained a great deal when we
have learned how thoroughly impotent, how truly irrelevant, is