e function is psychic and physiological, or physical. When
the action of the brain is confined within the cranium, its action is
purely psychic; but when its influence passes into the body, it
produces physiological effects. As the brain is the seat of the soul,
its action is essentially and primarily psychic; but as it is the
commander of the body, and the source of its spiritual vitality, all
its conditions or actions affect the body; and hence every organ has
its dual action, psychic and physiological. Cerebral physiology and
sarcognomy explain in detail how the brain and the mental conditions
affect the body; cerebral psychology shows how the brain and soul are
correlated. The purpose of this treatise is to show how the brain is
correlated with both soul and body, giving the principal attention to
the former.

If cerebral organs all have this double function, it is manifestly
exceedingly difficult, if not impossible, to find any words competent
to express the double functions, and it will be necessary to adapt our
nomenclature to expressing the psychic function, leaving the
physiological to be expressed otherwise. As the basilar organs act
more directly upon the body, their nomenclature will be more
suggestive of physiological effects. The organ, for example, of
alimentiveness or appetite will suggest by its name its relation to
the stomach.

The difficulty of arranging a satisfactory nomenclature for a certain
portion of the brain, in consequence of the varying energy of organic
action, is very great, and must be met by using the word which will
express in a general manner the organic tendency, leaving to the
intelligence of the reader to imagine the variations of intensity. In
the greatest energy of organic action the opposite faculty is entirely
overcome, and the conduct becomes abnormal, for normal action implies
the harmonious co-operation of all parts of the brain. Nevertheless,
it is in this abnormal or excessive action that we get the true,
isolated tendency or function in its naked expression.

For example, if we refer to that portion of the brain near the mastoid
process, which in its excessive action produces murder, we perceive
that as murder is an abnormal action, such a term is not a suitable
name for an organ, as it would convey the impression that every human
being has a constant murderous impulse, and that the faculty is kept
inactive when murder is not committed; from which we might infer that