erations of the brain in
thought, there can be no longer any question that in these operations of
the brain we have what I may term the objective machinery of thought.
'Not every thought to every thought succeeds indifferently,' said
Hobbes. Starting from this fact, modern physiology has clearly shown why
it is a fact; and looking to the astonishing rate at which the science
of physiology is now advancing, I think we may fairly expect that within
a time less remote than the two centuries which now separate us from
Hobbes, the course of ideas in a given train of thought will admit of
having its footsteps tracked in the corresponding pathways of the brain.
Be this, however, as it may, even now we know enough to say that,
whether or not these footsteps will ever admit of being thus tracked in
detail, they are all certainly present in the cerebral structures of
each one of us. What we know on the side of mind as logical sequence, is
on the side of the nervous system nothing more than a passage of nervous
energy through one series of cells and fibres rather than through
another: what we recognize as truth is merely the fact of the brain
vibrating in tune with Nature.

* * * * *

Such being the intimate relation between nerve-action and mind-action,
it has become the scientifically orthodox teaching that the two stand to
one another in the relation of cause to effect. One of the most
distinguished of my predecessors in this place, the President of the
Royal Society, has said in one of the most celebrated of his
lectures:--'We have as much reason for regarding the mode of motion of
the nervous system as the cause of the state of consciousness, as we
have for regarding any event as the cause of another.' And, by way of
perfectly logical deduction from this statement, Professor Huxley argues
that thought and feeling have nothing whatever to do with determining
action: they are merely the bye-products of cerebration, or, as he
expresses it, the indices of changes which are going on in the brain.
Under this view we are all what he terms conscious automata, or machines
which happen, as it were by chance, to be conscious of some of their own
movements. But the consciousness is altogether adventitious, and bears
the same ineffectual relation to the activity of the brain as a
steam-whistle bears to the activity of a locomotive, or the striking of
a clock to the time-keeping adjustments of the clock-work