CONTENTS.

CHAPTER I.

PAGE

Introductory1

Psychology defined; psychology as a natural science, its data, 1. The human mind and its environment, 3. The postulate that all consciousness has cerebral activity for its condition, 5.

CHAPTER II.

Sensation in General9

Incoming nerve-currents, 9. Terminal organs, 10. 'Specific energies,' 11. Sensations cognize qualities, 13. Knowledge of acquaintance and knowledge-about, 14. Objects of sensation appear in space, 15. The intensity of sensations, 16. Weber's law, 17. Fechner's law, 21. Sensations are not psychic compounds, 23. The 'law of relativity,' 24. Effects of contrast, 26.

CHAPTER III.

Sight28

The eye, 28. Accommodation, 32. Convergence, binocular vision, 33. Double images, 36. Distance, 39. Size, color, 40. After-images, 43. Intensity of luminous objects, 45.

CHAPTER IV.

Hearing47

The ear, 47. The qualities of sound, 43. Pitch, 44. 'Timbre,' 45. Analysis of compound air-waves, 56. No fusion of elementary sensations of sound, 57. Harmony and discord, 58. Discrimination by the ear, 59.

CHAPTER V.

Touch, the Temperature Sense, the Muscular Sense, and Pain60

End-organs in the skin, 60. Touch, sense of pressure, 60. Localization, 61. Sensibility to temperature, 63. The muscular sense, 65. Pain, 67.

CHAPTER VI.

Sensations of Motion70

The feeling of motion over surfaces, 70. Feelings in joints, 74. The sense of translation, the sensibility of the semicircular canals, 75.

CHAPTER VII.

The Structure of the Brain78

Embryological sketch, 78. Practical dissection of the sheep's brain, 81.

CHAPTER VIII.

The Functions of the Brain91

General idea of nervous function, 91. The frog's nerve-centres, 92. The pigeon's nerve-centres, 96. What the hemispheres do, 97. The automaton-theory, 101. The localization of functions, 104. Brain and mind have analogous 'elements,' sensory and motor, 105. The motor zone, 106. Aphasia, 108. The visual region, 110. Mental blindness, 112. The auditory region, mental deafness, 113. Other centres, 116.

CHAPTER IX.

Some General Conditions of Neural Activity120

The nervous discharge, 120. Reaction-time, 121. Simple reactions, 122. Complicated reactions, 124. The summation of stimuli, 128. Cerebral blood-supply, 130. Brain-thermometry, 131. Phosphorus and thought, 132.

CHAPTER X.

Habit134

Its importance, and its physical basis, 134. Due to pathways formed in the centres, 136. Its practical uses, 138. Concatenated acts, 140. Necessity for guiding sensations in secondarily automatic performances, 141. Pedagogical maxims concerning the formation of habits, 142.

CHAPTER XI.

The Stream of Consciousness151

Analytic order of our study, 151. Every state of mind forms part of a personal consciousness, 152. The same state of mind is never had twice, 154. Permanently recurring ideas are a fiction, 156. Every personal consciousness is continuous, 157. Substantive and transitive states, 160. Every object appears with a 'fringe' of relations, 163. The 'topic' of the thought, 167. Thought may be rational in any sort of imagery, 168. Consciousness is always especially interested in some one part of its object, 170.

CHAPTER XII.

The Self176

The Me and the I, 176. The material Me, 177. The social Me, 179. The spiritual Me, 181. Self-appreciation, 182. Self-seeking, bodily, social, and spiritual, 184. Rivalry of the Mes, 186. Their hierarchy, 190. Teleology of self-interest, 193. The I, or 'pure ego,' 195. Thoughts are not compounded of 'fused' sensations, 196. The 'soul' as a combining medium, 200. The sense of personal identity, 201. Explained by identity of function in successive passing thoughts, 203. Mutations of the self, 205. Insane delusions, 207. Alternating personalities, 210. Mediumships or possessions, 212. Who is the Thinker, 215.

CHAPTER XIII.

Attention217

The narrowness of the field of consciousness, 217. Dispersed attention, 218. To how much can we attend at once? 219. The varieties of attention, 220. Voluntary attention, its momentary character, 224. To keep our attention, an object must change, 226. Genius and attention, 227. Attention's physiological conditions, 228. The sense-organ must be adapted, 229. The idea of the object must be aroused, 232. Pedagogic remarks, 236. Attention and free-will, 237.

CHAPTER XIV.

Conception239

Different states of mind can mean the same, 239. Conceptions of abstract, of universal, and of problematic objects, 240. The thought of 'the same' is not the same thought over again, 243.

CHAPTER XV.

Discrimination244

Discrimination and association; definition of discrimination, 244. Conditions which favor it, 245. The sensation of difference, 246. Differences inferred, 248. The analysis of compound objects, 248. To be easily singled out, a quality should already be separately known, 250. Dissociation by varying concomitants, 251. Practice improves discrimination, 252.

CHAPTER XVI.

Association253

The order of our ideas, 253. It is determined by cerebral laws, 255. The ultimate cause of association is habit, 256. The elementary law in association, 257. Indeterminateness of its results, 258. Total recall, 259. Partial recall, and the law of interest, 261. Frequency, recency, vividness, and emotional congruity tend to determine the object recalled, 264. Focalized recall, or 'association by similarity,' 267. Voluntary trains of thought, 271. The solution of problems, 273. Similarity no elementary law; summary and conclusion, 277.

CHAPTER XVII.

The Sense of Time280

The sensible present has duration, 280. We have no sense for absolutely empty time, 281. We measure duration by the events which succeed in it, 283. The feeling of past time is a present feeling, 285. Due to a constant cerebral condition, 286.

CHAPTER XVIII.

Memory287

What it is, 287. It involves both retention and recall, 289. Both elements explained by paths formed by habit in the brain, 290. Two conditions of a good memory, persistence and numerousness of paths, 292. Cramming, 295. One's native retentiveness is unchangeable, 296. Improvement of the memory, 298. Recognition, 299. Forgetting, 300. Pathological conditions, 301.

CHAPTER XIX.

Imagination302

What it is, 302. Imaginations differ from man to man; Galton's statistics of visual imagery, 303. Images of sounds, 306. Images of movement, 307. Images of touch, 308. Loss of images in aphasia, 309. The neural process in imagination, 310.

CHAPTER XX.

Perception312

Perception and sensation compared, 312. The perceptive state of mind is not a compound, 313. Perception is of definite things, 316. Illusions, 317. First type: inference of the more usual object, 318. Second type: inference of the object of which our mind is full, 321. 'Apperception,' 326. Genius and old-fogyism, 327. The physiological process in perception, 329. Hallucinations, 330.

CHAPTER XXI.

The Perception of Space335

The attribute of extensity belongs to all objects of sensation, 335. The construction of real space, 337. The processes which it involves: 1) Subdivision, 338; 2) Coalescence of different sensible data into one 'thing,' 339; 3) Location in an environment, 340; 4) Place in a series of positions, 341; 5) Measurement, 342. Objects which are signs, and objects which are realities, 345. The 'third dimension,' Berkeley's theory of distance, 346. The part played by the intellect in space-perception, 349.

CHAPTER XXII.

Reasoning351

What it is, 351. It involves the use of abstract characters, 353. What is meant by an 'essential' character, 354. The 'essence' varies with the subjective interest, 358. The two great points in reasoning, 'sagacity' and 'wisdom,' 360. Sagacity, 362. The help given by association by similarity, 364. The reasoning powers of brutes, 367.

CHAPTER XXIII.

Consciousness and Movement370

All consciousness is motor, 370. Three classes of movement to which it leads, 372.

CHAPTER XXIV.

Emotion373

Emotions compared with instincts, 373. The varieties of emotion are innumerable, 374. The cause of their varieties, 375. The feeling, in the coarser emotions, results from the bodily expression, 375. This view must not be called materialistic, 380. This view explains the great variability of emotion, 381. A corollary verified, 382. An objection replied to, 383. The subtler emotions, 384. Description of fear, 385. Genesis of the emotional reactions, 386.

CHAPTER XXV.

Instinct391

Its definition, 391. Every instinct is an impulse, 392. Instincts are not always blind or invariable, 395. Two principles of non-uniformity, 398. Enumeration of instincts in man, 406. Description of fear, 407.

CHAPTER XXVI.

Will415

Voluntary acts, 415. They are secondary performances, 415. No third kind of idea is called for, 418. The motor-cue, 420. Ideo-motor action, 432. Action after deliberation, 428. Five chief types of decision, 429. The feeling of effort, 434. Healthiness of will, 435. Unhealthiness of will, 436. The explosive will: (1) from defective inhibition, 437; (2) from exaggerated impulsion, 439. The obstructed will, 441. Effort feels like an original force, 442. Pleasure and pain as springs of action, 444. What holds attention determines action, 448. Will is a relation between the mind and its 'ideas,' 449. Volitional effort is effort of attention, 450. The question of free-will, 455. Ethical importance of the phenomenon of effort, 458.

EPILOGUE.

Psychology and Philosophy461

What the word metaphysics means, 461. Relation of consciousness to the brain, 462. The relation of states of mind to their 'objects,' 464. The changing character of consciousness, 466. States of consciousness themselves are not verifiable facts, 467.