1868. | Mathematical and Physical Science. 511 
passions or affections are excited, it is through the instrumentality 
of the brain. We may admit the extreme probability of the hypo- 
thesis, that for every fact of consciousness, whether in the domain of 
sense, of thought, or of emotion, a certain definite molecular con- 
dition is set up in the brain; that this relation of physics to 
consciousness is invariable, so that, given the state of the brain, the 
corresponding thought or feeling might be inferred; or given the 
thought or feeling, the corresponding state of the brain might be 
inferred. But granted that a definite thought and a definite mole- 
cular 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 electric 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 consciousness?” The chasm between the two classes 
of phenomena would still remain intellectually impassable. The 
speaker concluded this address in the following eloquent words :— 
“Tn affirming that the growth of the body is mechanical, and 
that thought, as exercised by us, has its correlative in the physics 
of the brain, I think the position of the ‘ Materialist’ is stated as 
far as that position is a tenable one. I think the materialist will 
be able finally to maintain this position against all attacks; but I 
do not think, as the human mind is at present constituted, that he 
can pass beyond it. I do not think he is entitled to say that his 
molecular groupings and his molecular motions explain everything. 
In reality they explain nothing. The utmost he can affirm is the 
association of two classes of phenomena, of whose real bond of union 
he is in absolute ignorance. The problem of the connection of 
body and soul is as insoluble in its modern form as it was in the 
pre-scientific ages. Phosphorus is known to enter into the com- 
position of the human brain, and a courageous writer has exclaimed, 
in his trenchant German, “Ohne Phosphor kein Gedanke.” That 
may or may not be the case; but even if we knew it to be the case, 
the knowledge would not lighten our darkness. On both sides of 
the zone here assigned to the materialist he is equally helpless. If 
you ask him whence is this ‘matter’ of which we have been dis- 
coursing, who or what divided it into molecules, who or what 
impressed upon them this necessity of running into organic forms, 
he has no answer. Science also is mute in reply to these questions. 
But if the materialist is confounded and science ee dumb, 
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