gers, and regarded the mere laws of their coexistence with
brain-states as the ultimate laws for our science. The
reader will in vain seek for any closed system in the book.
It is mainly a mass of descriptive details, running out into
queries which only a metaphysics alive to the weight of
her task can hope successfully to deal with. That will
perhaps be centuries hence; and meanwhile the best mark
of health that a science can show is this unfinished-seeming
front.

The completion of the book has been so slow that
several chapters have been published successively in Mind,
the Journal of Speculative Philosophy, the Popular Science
Monthly, and Scribner's Magazine. Acknowledgment is
made in the proper places.

The bibliography, I regret to say, is quite unsystem-
atic. I have habitually given my authority for special
experimental facts; but beyond that I have aimed mainly
to cite books that would probably be actually used by
the ordinary American college-student in his collateral
reading. The bibliography in W. Volkmann von Volkmar's
Lehrbuch der Psychologie (1875) is so complete, up to its
date, that there is no need of an inferior duplicate. And
for more recent references, Sully's Outlines, Dewey's Psy-
chology, and Baldwin's Handbook of Psychology may be
advantageously used.

Finally, where one owes to so many, it seems absurd to
single out particular creditors; yet I cannot resist the
temptation at the end of my first literary venture to record
my gratitude for the inspiration I have got from the writ-
ings of J. S. Mill, Lotze, Renouvier, Hodgson, and Wundt,
and from the intellectual companionship (to name only five
names) of Chauncey Wright and Charles Peirce in old
times, and more recently of Stanley Hall, James Putnam,
and Josiah Royce.

HARVARD UNIVERSITY, August 1890.

CONTENTS.

CHAPTER I.

THE SCOPE OF PSYCHOLOGY,

Mental Manifestations depend on Cerebral Conditions, 1.
Pursuit of ends and choice are the marks of Mind's presence, 6.

CHAPTER II.

THE FUNCTIONS OF THE BRAIN, .

Reflex, semi-reflex, and voluntary acts, 12. The Frog's nervecentres, 14. General notion of the hemispheres, 20. Their Education-the Meynert scheme, 24. The phrenological contrasted with the physiological conception, 27. The localization of function in the hemispheres, 30. The motor zone, 31. Motor Aphasia, 37. The sight-centre, 41. Mental blindness, 48. The hearing-centre, 52. Sensory Aphasia, 54. Centres for smell and taste, 57. The touch-centre, 58. Man's Consciousness limited to the hemispheres, 65. The restitution of function, 67. Final correction of the Meynert scheme, 72. Conclusions, 78.

CHAPTER III.

ON SOME GENERAL CONDITIONS OF BRAIN-ACTIVITY,

The summation of Stimuli, 82. Reaction-time, 85. Cerebral blood-supply, 97. Cerebral Thermometry, 99. Phosphorus and Thought, 101.

HABIT, .

CHAPTER IV.

Due to plasticity of neural matter, 105. Produces ease of action, 112. Diminishes attention, 115. Concatenated perform. ances, 116. Ethical implications and pedagogic maxims, 120.

The theory described, 128. Reasons for it, 188. Reasons against it, 188.

PAGE

1

12

81

104

. 128

Evolutionary Psychology demands a Mind-dust, 146. Some alleged proofs that it exists, 150. Refutation of these proofs, 154. Self-compounding of mental facts is inadmissible, 158. Can states of mind be unconscious? 162. Refutation of alleged proofs of unconscious thought, 164. Difficulty of stating the connection between mind and brain, 176. The Soul' is logically the least objectionable hypothesis, 180. Conclusion, 182.

PAGE

145

Psychology is a natural Science, 183. Introspection, 185. Experiment, 192. Sources of error, 194. The 'Psychologist's fallacy,' 196.

Time relations: lapses of Consciousness-Locke v. Descartes, 200. The unconsciousness' of hysterics not genuine, 202. Minds may split into dissociated parts, 206. Space-relations : the Seat of the Soul, 214. Cognitive relations, 216. The Psychologist's point of view, 218. Two kinds of knowledge, acquaintance and knowledge about, 221.

CHAPTER IX.

THE STREAM OF THOUGHT,

Consciousness tends to the personal form, 225. It is in constant change, 229. It is sensibly continuous, 237. Substantive' and 'transitive' parts of Consciousness, 243. Feelings of relation, 245. Feelings of tendency, 249. The 'fringe of the object, 258. The feeling of rational sequence, 261. Thought possible in any kind of mental material, 265. Thought and language, 267. Consciousness is cognitive, 271. The word Object, 275. Every cognition is due to one integral pulse of thought, 276. Diagrams of Thought's stream, 279. Thought is always selective, 284.

199

224

The Empirical Self or Me, 291. Its constituents, 292. The material self, 292. The Social Self, 293. The Spiritual Self, 296. Difficulty of apprehending Thought as a purely spiritual activity,

291

299. Emotions of Self, 305. Rivalry and conflict of one's different
selves, 309. Their hierarchy, 313. What Self we love in 'Self-
love,' 317. The Pure Ego, 329. The verifiable ground of the
sense of personal identity, 332. The passing Thought is the only
Thinker which Psychology requires, 338. Theories of Self-con-
sciousness: 1) The theory of the Soul, 342. 2) The Associationist
theory, 350. 3) The Transcendentalist theory, 360. The muta-
tions of the Self, 373. Insane delusions, 375. Alternating selves,
879. Mediumships or possessions, 393. Summary, 400.

CHAPTER XI.

PAGE

. 402

ATTENTION,

Its neglect by English psychologists, 402. Description of it, 404. To how many things can we attend at once? 405. Wundt's experiments on displacement of date of impressions simultaneously attended to, 410. Personal equation, 413. The varieties of attention, 416. Passive attention, 418. Voluntary attention, 420. Attention's effects on sensation, 425;-on discrimination, 426 ;on recollection, 427;-on reaction-time, 427. The neural process in attention : 1) Accommodation of sense-organ, 434. 2) Preperception, 438. Is voluntary attention a resultant or a force? 447. The effort to attend can be conceived as a resultant, 450. Conclusion, 453. Acquired Inattention, 455.

. CONCEPTION,

CHAPTER XII.

The sense of sameness, 459. ceptions are unchangeable, 464.

Conception defined, 481. Con-
Abstract ideas, 468. Universals,

473. The conception of the same' is not the same state' of
mind, 480.

Simul

Locke on discrimination, 483. Martineau ditto, 484.
taneous sensations originally fuse into one object, 488. The
principle of mediate comparison, 489. Not all differences are
differences of composition, 490. The conditions of discrimina-
tion, 494. The sensation of difference, 495. The transcendental-
ist theory of the perception of differences uncalled for, 498. The
process of analysis, 502. The process of abstraction, 505. The
improvement of discrimination by practice, 508. Its two causes,
510. Practical interests limit our discrimination, 515. Reaction-
time after discrimination, 523. The perception of likeness, 528.
The magnitude of differences, 530. The measurement of dis-