s are supposed to be physical and the
effects mental. And the antithesis thus posited is alone sufficient to
separate _toto coelo_ the case of causation supposed from that of all
cases of causation recognized. From the singularly clear and
well-balanced statement of this subject given by Professor Allman in his
Presidential Address before the British Association, I may here fitly
quote the following:--

'If we could see any analogy between thought and any one of the
admitted phenomena of matter, we should be justified in the first
of these conclusions (i. e. that of Materialism) as the simplest,
and as affording a hypothesis most in accordance with the
comprehensiveness of natural laws; but between thought and the
physical phenomena of matter there is not only no analogy, but no
conceivable analogy; and the obvious and continuous path which we
have hitherto followed up in our reasonings from the phenomena of
lifeless matter through those of living matter here comes suddenly
to an end. The chasm between unconscious life and thought is deep
and impassable, and no transitional phenomena can be found by
which, as by a bridge, we may span it over[6].'

And, not unduly to multiply quotations, I shall only adduce one more
from another of the few eminent men of science who have seen their way
clearly in this matter, and have expressed what they have seen in
language as clear as their vision. Professor Tyndall writes:--

'The passage from the physics of the brain to the corresponding
facts of consciousness is unthinkable. Granted that a definite
thought and a definite molecular action in the brain occur
simultaneously, we do not possess the intellectual organ, nor
apparently any rudiment of the organ, which would enable us to
pass, by a process of reasoning, from the one phenomenon to the
other. They appear together but we do not know why. Were our minds
and senses so expanded, strengthened, and illuminated, as to enable
us to see and feel the very molecules of the brain; were we capable
of following all their motions, all their groupings, all their
electrical discharges, if such there be; and were we intimately
acquainted with the corresponding states of thought and feeling, we
should be as far as ever from the solution of the problem. How are
these physical processes connected with the facts of co