of the brain. The resulting brain change
is regarded as the true concomitant of the sensation. If there is a
brain change of a certain kind, there is the corresponding sensation.
It need hardly be said that no one knows as yet much about the brain
motions which are supposed to be concomitants of sensations, although a
good deal is said about them.

It is very important to remark that in all this no new meaning has been
given to the word "concomitance." The plain man remarks that
sensations and their changes must be referred to the body. With the
body disposed in a certain way, he has sensations of a certain kind;
with changes in the body, the sensations change. He does not perceive
the sensations to be in the body. As I recede from a house I have a
whole series of visual experiences differing from each other and ending
in a faint speck which bears little resemblance to the experience with
which I started. I have had, as we say, a series of sensations, or
groups of such. Did any single group, did the experience which I had
at any single moment, seem to me to be _in my body_? Surely not. Its
relation to my body is other than that.

And when the man of science, instead of referring sensations vaguely to
the body, refers them to the brain, the reference is of precisely the
same nature. From our common experience of the relation of the
physical and the mental he starts out. He has no other ground on which
to stand. He can only mark the reference with greater exactitude.

I have been speaking of the relation of sensations to the brain. It is
scarcely necessary for me to show that all other mental phenomena must
be referred to the brain as well, and that the reference must be of the
same nature. The considerations which lead us to refer ideas to the
brain are set forth in our physiologies and psychologies. The effects
of cerebral disease, injuries to the brain, etc., are too well known to
need mention; and it is palpably as absurd to put ideas in the brain as
it is to put sensations there.

Now, the parallelist, if he be a wise man, will not attempt to
_explain_ the reference of mental phenomena to the brain--to _explain_
the relation between mind and matter. The relation appears to be
unique. Certainly it is not identical with the relation between two
material things. We explain things, in the common acceptation of the
word, when we show that a case under consideration is an
exemplification of some gen