the
subjective--between molecular motions and states of consciousness?
My answer is: I do not see the connection, nor am I acquainted with
anybody who does. It is no explanation to say that the objective
and subjective are two sides of one and the same phenomenon.
Why should the phenomenon have two sides? This is the very core
of the difficulty. There are plenty of molecular motions which
do exhibit this two-sidedness. Does water think or feel when it
runs into frost-ferns upon a window pane? If not, why should
the molecular motion of the brain be yoked to this mysterious
companion--consciousness? We can form a coherent picture of all the
purely physical processes--the stirring of the brain, the thrilling of
the nerves, the discharging of the muscles, and all the subsequent
motions of the organism. We are here dealing with mechanical problems
which are mentally presentable.

But we can form no picture of the process whereby consciousness
emerges, either as a necessary link, or as an accidental by-product,
of this series of actions. The reverse process of the production of
motion by consciousness is equally unpresentable to the mind. We are
here in fact on the boundary line of the intellect, where the ordinary
canons of science fail to extricate us. If we are true to these
canons, we must deny to subjective phenomena all influence on physical
processes. The mechanical philosopher, as such, will never place a
state of consciousness and a group of molecules in the relation of
mover and moved. Observation proves them to interact; but, in passing
from the one to the other, we meet a blank which the logic of
deduction is unable to fill. This, the reader will remember, is the
conclusion at which I had arrived more than twenty years ago. I lay
bare unsparingly the central difficulty of the materialist, and tell
him that the facts of observation which he considers so simple are
'almost as difficult to be seized mentally as the idea of a soul.' I go
further, and say, in effect, to those who wish to retain this idea,
'If you abandon the interpretations of grosser minds, who image the
soul as a Psyche which could be thrown out of the window--an entity
which is usually occupied, we know not how, among the molecules of the
brain, but which on due occasion, such as the intrusion of a bullet or
the blow of a club, can fly away into other regions of space--if,
abandoning this heathen notion, you consent to approach the su