Chapter VII: The Nature of Emotion 91

Analogy between perception and emotion—Constituent
elements of emotion—Summary of the theory of James and
Lange—Application of this theory to the higher emotions
(religious, moral, æsthetic, intellectual)—Illegitimate
confusion between the quality and intensity of
emotion—Examination of a typical case: musical emotion—The
most emotional of all the arts is the most dependent on
physiological conditions—Proofs: its action on animals, on
primitive man, on civilised man; its therapeutic
action—Why certain sensations, images, and ideas awaken
organic and motor states, and, consequently, emotion—They
are connected either with natural or social conditions of
existence—Differences and resemblances between the two
cases—Antecedents of the physiological theory of
emotion—Dualist position, or that of the relation between
cause and effect—Unitary position; its advantages.

CHAPTER VIII.

THE INTERNAL CONDITIONS OF EMOTION 113

Confused state of this question—Popular _versus_ Medical
Psychology—Part played by the brain, the centre of psychic
life—Hypotheses on the “seat” of the emotions—Part played
by the heart, the centre of vegetative life—Popular
metaphors and their physiological interpretation—Are the
internal sensations reducible to a single process?—Part
played by chemical action in the genesis of emotion—Cases
of the introduction of toxic
substances—Auto-intoxication—Modifications in the course
of mental maladies.

CHAPTER IX.

THE EXTERNAL CONDITIONS OF EMOTION 124

Empiric period—Pre-Darwinian period of scientific
research—Examination of Darwin’s three principles—Wundt
and his explanatory formulas: Innervation directly
modified, Association of analogous sensations, Relations
of motion with sensory representations.

CHAPTER X.

CLASSIFICATIONS 130

Their discrepancies—Reduced to three types: (1)
Classification of pleasures and pains—(2) Classification
of emotions: two forms, empiric and
analytico-comparative—(3) Classification of
representations, intellectualist form—Critical
remarks—Impossibility of any classification.