able possibility
that units of external force may be identical in nature with the units of
the force known as feeling." Let us then ascertain how far it is true that
the argument already quoted, and which leads to this conclusion, is utterly
destructive of Materialism.

In the first place, I may observe that this argument differs in several
instructive particulars from the anti-materialistic argument of Locke,
which we have already had occasion to consider. For while Locke erroneously
imagined that the test of inconceivability is of equivalent value
_wherever_ it is applied, save only where it conflicts with preconceived
ideas on the subject of Theism (see Appendix A.), Spencer, of course, is
much too careful a thinker to fall into so obvious a fallacy. But again, it
is curious to observe that in the anti-materialistic argument of Spencer
the test of inconceivability is used in a manner the precise opposite of
that in which it is used in the anti-materialistic argument of Locke. For
while the ground of Locke's argument is that Materialism must be untrue
because it is inconceivable that Matter (and Force) should be of a
psychical nature; the ground of Spencer's argument is that what we know as
Force (and Matter) may _not_ inconceivably be of a psychical nature. For my
own part, I think that Spencer's argument is, psychologically speaking, the
more valid of the two; but nevertheless I think that, logically speaking,
it is likewise invalid to a perceptibly great, and to a further indefinite,
degree. For the argument sets out with the reflection that we can only know
Matter and Force as symbols of consciousness, while we know consciousness
directly, and therefore that we can go further in conceivably translating
Matter and Force into terms of Mind than _vice versa_. And this is true,
but it does not therefore follow that the truth is more likely to lie in
the direction that thought can most easily travel. For although I am at one
with Mr. Spencer, whom Mr. Fiske follows, in regarding his test of
truth--viz., inconceivability of a negation--as the most _ultimate_ test
within our reach, I cannot agree with him that in this particular case it
is the most _trustworthy_ test within our reach. I cannot do so because the
reflection is forced upon me that, "as the terms which are contemplated in
this particular case are respectively the highest abstractions of objective
and of subjective existence, the test of truth in question is ne