. Here, again,
we meet with an echo of Hobbes, who opens his work on the Commonwealth
with these words:--

'Nature, the art whereby God hath made and governs the world, is by
the _art_ of man, as in many other things, in this also imitated,
that it can make an artificial animal. For seeing life is but a
motion of limbs, the beginning whereof is in the principal part
within; why may we not say, that all _automata_ (engines that move
themselves by springs and wheels as doth a watch), have an
artificial life? For what is the _heart_, but a _spring_; and the
_nerves_, but so many _strings_; and the _joints_, but so many
_wheels_, giving motion to the whole body, such as was intended by
the artificer[2]?'

Now, this theory of conscious automatism is not merely a legitimate
outcome of the theory that nervous changes are the causes of mental
changes, but it is logically the only possible outcome. Nor do I see any
way in which this theory can be fought on grounds of physiology. If we
persist in regarding the association between brain and thought
exclusively from a physiological point of view, we must of necessity be
materialists. Further, so far as we are physiologists our materialism
can do us no harm. On the contrary, it is to us of the utmost service,
as at once the simplest physiological explanation of facts already
known, and the best working hypothesis to guide us in our further
researches. But it does not follow from this that the theory of
materialism is true. The bells of St. Mary's over the way always ring
for a quarter of an hour before the University sermon; yet the ringing
of the bells is not the cause of the sermon, although, as long as the
association remains constant, there would be no harm in assuming, for
any practical purposes, that it is so. But just as we should be wrong in
concluding, if we did not happen to know so much about the matter as we
do, that the University sermon is produced by the vibration of bells in
the tower of St. Mary's Church, so we may be similarly wrong if we were
definitely to conclude that the sermon is produced by the vibration of a
number of little nerve-cells in the brain of the preacher.

Now, if time permitted, and if I supposed that you would all care to go
with me into matters of some abstruseness, I could certainly prove that
whatever the connexion between body and mind may be, we have the best
possible reasons for concludi