omena is so
great as to justify the belief that the _substances_ are different and
ought to be denominated by distinctive names.

When Materialists affirm, as they do, the existence of one only
substantive being in Nature, and represent all our mental phenomena as
the mere results of physical organization, they assume that "matter," at
least, is a real _entity_; that it is a _substance_ or _substratum_ in
which certain powers or qualities inhere; and that its existence, as
such, is evident and undeniable. We are entirely relieved, therefore, by
their own admission or assumption, from the necessity of discussing the
more general problem of Ontology; the problem, whether we can prove the
existence of _any_ being, properly so called, from a mere series of
phenomena, a succession of appearances. They virtually admit, since they
evidently assume, that the phenomena must have a substance under them,
the qualities a substratum in which they inhere. Now, the very same
reason which warrants, or rather obliges them to recognize "matter" as a
substance and not as a shadow,--as an _entity_ which really exists and
manifests itself by its properties and effects,--must equally warrant,
or rather oblige them to recognize "mind" or "spirit" also as a
distinct substantive being, unless it can be shown either that its
properties are the same with those of matter, or that they may be
accounted for by some peculiar modification of matter, some law of
physical organization. There can be no reason for admitting the
existence of "matter" as a substance, which does not apply also to the
existence of "mind" as a distinct substance, if it shall be found that
their properties are essentially different. We know, and can know,
nothing of _substance_ otherwise than by its properties or powers: we
know nothing of "matter,"--it would, in fact, be to us non-existent, but
for its extension, solidity, and other properties; we know nothing of
"mind,"--it would equally be to us non-existent, but for its
consciousness, its thoughts, feelings, and desires; and if it be right
to ascribe the one set of properties to a substantive being, called
"matter," it cannot be wrong to ascribe the other set of properties also
to a substantive being, called "mind."

If it could be shown, indeed, that the properties of the one substance
might either be identified with, or accounted for, by those of the
other; if animal feeling could be identified with or derived from, mere