BOOK I PART IV
trary, are susceptible of a constant conjunction,
and as no real objects are contrary: it follows,
that for ought we can determine by the mere
ideas, any thing may be the cause or effect of
any thing; which evidently gives the advantage
to the materialists above their antagonists.
To pronounce, then, the final decision upon
the whole; the question concerning the sub-
stance of the soul is absolutely unintelligible:
All our perceptions are not susceptible of a lo-
cal union, either with what is extended or un-
extended: there being some of them of the one
kind, and some of the other: And as the con-
stant conjunction of objects constitutes the very
essence of cause and effect, matter and motion
may often be regarded as the causes of thought,
as far as we have any notion of that relation.
It is certainly a kind of indignity to philos-