Chapter I: Front Matter

THE PRINCIPLES OF PSYCHOLOGY

BY

WILLIAM JAMES

PROFESSOR OF PSYCHOLOGY IN HARVARD UNIVERSITY

IN TWO VOLUMES

VOL II.

NEW YORK

HENRY HOLT AND COMPANY

1918

CONTENTS.

CHAPTER XVII.

SENSATION

Its distinction from perception. Its cognitive function--acquaintance with qualities. No pure sensations after the first days of life. The 'relativity of knowledge'. The law of contrast. The psychological and the physiological theories of it. Hering's experiments. The 'eccentric projection' of sensations.

CHAPTER XVIII.

IMAGINATION

Our images are usually vague. Vague images not necessarily general notions. Individuals differ in imagination; Gabon's researches. The 'visile' type, 58. The 'audile' type. The 'motile' type. Tactile images, 65. The neural process of imagination. Its relations to that of sensation.

CHAPTER XIX.

THE PERCEPTION OF 'THINGS'

Perception and sensation. Perception is of definite and probable things. Illusions;--of the first type;--of the second type. The neural process in perception. 'Apperception'. Is perception an unconscious inference? Hallucinations, 114. The neural process in hallucination. Binet's theory. 'Perception-time'.

CHAPTER XX.

THE PERCEPTION OF SPACE

The feeling of crude extensity. The perception of spatial order. Space-'relations'. The meaning of localization. 'Local signs'. The construction of 'real' space. The subdivision of the original sense-spaces. The sensation of motion over surfaces. The measurement of the sense-spaces by each other. Their summation. Feelings of movement in joints. Feelings of muscular contraction. Summary so far. How the blind perceive space. Visual space. Helmholtz and Reid on the test of a sensation. The theory of identical points. The theory of projection. Ambiguity of retinal impressions;--of eye-movements. The choice of the visual reality. Sensations which we ignore. Sensations which seem suppressed. Discussion of Wundt's and Helmholtz's reasons for denying that retinal sensations are of extension. Summary. Historical remarks.

CHAPTER XXI.

THE PERCEPTION OF REALITY

Belief and its opposites. The various orders of reality. 'Practical' realities. The sense of our own bodily existence is the nucleus of all reality. The paramount reality of sensations. The influence of emotion and active impulse on belief. Belief in theories. Doubt. Relations of belief and will.

CHAPTER XXII.

REASONING

'Recepts'. In reasoning, we pick out essential qualities. What is meant by a mode of conceiving. What is involved in the existence of general propositions. The two factors of reasoning. Sagacity. The part played by association by similarity. The intellectual contrast between brute and man: association by similarity the fundamental human distinction. Different orders of human genius.

CHAPTER XXIII.

THE PRODUCTION OF MOVEMENT

The diffusive wave. Every sensation produces reflex effects on the whole organism.

CHAPTER XXIV.

INSTINCT

Its definition. Instincts not always blind or invariable. Two principles of non-uniformity in instincts: 1) Their inhibition by habits; 2) Their transitoriness. Man has more instincts than any other mammal. Reflex impulses. Imitation. Emulation. Pugnacity. Sympathy. The hunting instinct. Fear. Acquisitiveness. Constructiveness. Play. Curiosity. Sociability and shyness. Secretiveness. Cleanliness. Shame. Love. Maternal love.

CHAPTER XXV.

THE EMOTIONS

Instinctive reaction and emotional expression shade imperceptibly into each other. The expression of grief; of fear; of hatred. Emotion is a consequence, not the cause, of the bodily expression. Difficulty of testing this view. Objections to it discussed. The subtler emotions, 468. No special brain-centres for emotion. Emotional differences between individuals. The genesis of the various emotions.

CHAPTER XXVI.

WILL

Voluntary movements: they presuppose a memory of involuntary movements. Kinæsthetic impressions, 488. No need to assume feelings of innervation. The 'mental cue' for a movement may be an image of its visual or auditory effects as well as an image of the way it feels. Ideo-motor action. Action after deliberation. Five types of decision. The feeling of effort. Unhealthiness of will: 1) The explosive type; 2) The obstructed type. Pleasure and pain are not the only springs of action. All consciousness is impulsive. What we will depends on what idea dominates in our mind. The idea's outward effects follow from the cerebral machinery. Effort of attention to a naturally repugnant idea is the essential feature of willing. The free-will controversy. Psychology, as a science, can safely postulate determinism, even if free-will be true. The education of the Will. Hypothetical brain-schemes.

CHAPTER XXVII.

HYPNOTISM

Modes of operating and susceptibility. Theories about the hypnotic state. The symptoms of the trance.