by which it can empirically control its theory. But this
whole idea of localisation does not hold good to anything like the extent
to which the members of the naturalistic school are wont to assert that it
does. In regard to this point, too, there has been considerable
disillusioning in recent years. Perhaps all that can be said is, that
localisation of psychical processes is a fact analogous to the fact that
sight is associated with the optic nerves and hearing with the auditory
nerves. Progressive investigation leads more and more clearly to the
recognition of a fact which makes localisation comparatively unimportant,
namely, the vicarious functioning of different parts of the brain. In many
cases where this or that "centre" is injured, and rendered incapable of
function, or even extirpated, the corresponding part of the mind is by no
means destroyed along with it. At first the mind may suffer from "the
effect of shock" as the phrase runs, but gradually it may recover and the
same function may be transferred to another part of the brain, and there
be fulfilled sometimes less perfectly, sometimes quite as perfectly as
before. We had to deal with this fact of vicarious function in discussing
the general theory of life. It is one of the greatest difficulties in the
way of the mechanistic and materialistic theories. But it must give some
trouble to the parallelists too.

We need not speak of the wonderful duplication of all existence which
parallelism must establish, though it is difficult to evade the question
how a _natura sive deus_ could have come, so superfluously, to say the
same thing twice over. Superfluously, for since both are alike
self-contained and independent of one another, one can have no need of the
other.

One objection, however, may be urged against both parallelism and
materialism, which makes them both impossible, and that is, automatism.
Both parallelism and materialism maintain that the sequence of physical
processes is complete in itself and can be explained in terms of itself.
_All_ physical processes! Not only the movements of the stars, the changes
in inanimate matter, the origin and evolution of the forms of life, but
also what we call actions, for instance the movements of our arms and our
legs, and the complicated processes affecting the breathing organs and
tongue, which we call "speech." Every plant, every animal, every human
being must be as it is and where it is, must move and act, must