nerve processes with the function of Impression and Expression in the
arts. But to understand something of what takes place in the making of
poetry we must now substitute for our first diagram the slightly more
complicated one which William James employs to represent, not those lower
nerve-centres which "act from present sensational stimuli alone," but the
hemispheres of the human brain which "act from considerations."
[Footnote: _Psychology, Briefer Course_, pp. 97, 98. Henry Holt.]
Considerations are images constructed out of past experience, they are
reproductions of what has been felt or witnessed.

"They are, in short, _remote_ sensations; and the main difference
between the hemisphereless animal and the whole one may be concisely
expressed by saying that _the one obeys absent, the other only present,
objects. The hemispheres would then seem to be the chief seat of
memory._"

Then follows the accompanying diagram and illustration.

"If we liken the nervous currents to electric currents, we can compare
the nervous system, _C_, below the hemispheres to a direct circuit from
sense-organ to muscle along the line _S... C... M_. The hemisphere, _H_,
adds the long circuit or loop-line through which the current may pass
when for any reason the direct line is not used.

[Illustration: M ?----- C ?----- H ?----- C ?---- S ]

"Thus, a tired wayfarer on a hot day throws himself on the damp earth
beneath a maple-tree. The sensations of delicious rest and coolness
pouring themselves through the direct line would naturally discharge
into the muscles of complete extension: he would abandon himself to the