ome Platonic speculator were to come along and
insist upon our leaving room for an alternative conclusion; suppose he
were to urge upon us that all this process of material development, with
the discovery of which our patient study has been rewarded, may be
but the temporary manifestation of 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
physical investigation in the presence of such a question. If we get not
much positive satisfaction for our unquiet yearnings, we occupy at any
rate a sounder philosophic position when we recognize the limits within
which our conclusions, whether positive or negative, are valid.

It seems not improbable that Mr. Mill may have had in mind something
like the foregoing considerations when he sug