ng that it is not a causal connexion. These
reasons are, of course, extra-physiological; but they are not on this
account less conclusive. Within the limits of a lecture, however, I can
only undertake to give an outline sketch of what I take to be the
overwhelming argument against materialism.

We have first the general fact that all our knowledge of motion, and so
of matter, is merely a knowledge of the modifications of mind. That is
to say, all our knowledge of the external world--including the knowledge
of our own brains--is merely a knowledge of our own mental states. Let
it be observed that we do not even require to go so far as the
irrefutable position of Berkeley, that the existence of an external
world without the medium of mind, or of being without knowing, is
inconceivable. It is enough to take our stand on a lower level of
abstraction, and to say that whether or not an external world can exist
apart from mind in any absolute or inconceivable sense, at any rate it
cannot do so _for us_. We cannot think any of the facts of external
nature without presupposing the existence of a mind which thinks them;
and therefore, so far at least as we are concerned, mind is necessarily
prior to everything else. It is for us the only mode of existence which
is real in its own right; and to it, as to a standard, all other modes
of existence which may be _in_ferred must be _re_ferred. Therefore, if
we say that mind is a function of motion, we are only saying, in
somewhat confused terminology, that mind is a function of itself.

Such, then, I take to be a general refutation of materialism. To use but
a mild epithet, we must conclude that the theory is unphilosophical,
seeing that it assumes one thing to be produced by another thing, in
spite of an obvious demonstration that the alleged effect is necessarily
prior to its cause. Such, I say, is a general refutation of
materialism. But this is far from being all. 'Motion,' says Hobbes,
'produceth nothing but motion;' and yet he immediately proceeds to
assume that in the case of the brain it produces, not only motion, but
mind. He was perfectly right in saying that with respect to its
movements the animal body resembles an engine or a watch; and if he had
been acquainted with the products of higher evolution in watch-making,
he might with full propriety have argued, for instance, that in the
compensating balance, whereby a watch adjusts its own movements in
adaptation to external c