It is inconceivable BECAUSE it is entirely without foundation in
experience. Our powers of conception are closely determined by
the limits of our experience. When a proposition, or combination
of ideas, is suggested, for which there has never been any
precedent in human experience, we find it to be UNTHINKABLE,--the
ideas will not combine. The proposition remains one which we may
utter and defend, and perhaps vituperate our neighbours for not
accepting, but it remains none the less an unthinkable
proposition. It takes terms which severally have meanings and
puts them together into a phrase which has no meaning.[11] Now
when we try to combine the idea of the continuance of conscious
activity with the idea of the entire cessation of material
conditions, and thereby to assert the existence of a purely
spiritual world, we find that we have made an unthinkable
proposition. We may defend our hypothesis as passionately as we
like, but when we strive coolly to realize it in thought we find
ourselves baulked at every step.

[11] See my Outlines of Cosmic Philosophy, Vol. I. pp. 64-67.


But now we have to ask, How much does this inconceivability
signify? In most cases, when we say that a statement is
inconceivable, we practically declare it to be untrue; when we
say that a statement is without warrant in experience, we plainly
indicate that we consider it unworthy of our acceptance. This is
legitimate in the majority of cases with which we have to deal in
the course of life, because experience, and the capacities of
thought called out and limited by experience, are our only guides