_BRIEFER COURSE_
PSYCHOLOGY
BY
WILLIAM JAMES
_Professor of Psychology in Harvard University_
London
MACMILLAN AND CO.
1892
COPYRIGHT, 1892,
BY
HENRY HOLT & CO.
ROBERT DRUMMOND,
_Electrotyper and Printer_,
New York.
PREFACE.
In preparing the following abridgment of my larger work, the Principles
of Psychology, my chief aim has been to make it more directly available
for class-room use. For this purpose I have omitted several whole
chapters and rewritten others. I have left out all the polemical and
historical matter, all the metaphysical discussions and purely
speculative passages, most of the quotations, all the book-references,
and (I trust) all the impertinences, of the larger work, leaving to the
teacher the choice of orally restoring as much of this material as may
seem to him good, along with his own remarks on the topics successively
studied. Knowing how ignorant the average student is of physiology, I
have added brief chapters on the various senses. In this shorter work
the general point of view, which I have adopted as that of 'natural
science,' has, I imagine, gained in clearness by its extrication from so
much critical matter and its more simple and dogmatic statement. About
two fifths of the volume is either new or rewritten, the rest is
'scissors and paste.' I regret to have been unable to supply chapters on
pleasure and pain, æsthetics, and the moral sense. Possibly the defect
may be made up in a later edition, if such a thing should ever be
demanded.
I cannot forbear taking advantage of this preface to make a statement
about the composition of the 'Principles of Psychology.' My critics in
the main have been so indulgent that I must cordially thank them; but
they have been unanimous in one reproach, namely, that my order of
chapters is planless and unnatural; and in one charitable excuse for
this, namely, that the work, being largely a collection of
review-articles, could not be expected to show as much system as a
treatise cast in a single mould. Both the reproach and the excuse
misapprehend the facts of the case. The order of composition is
doubtless unshapely, or it would not be found so by so many. But
planless it is not, for I deliberately followed what seemed to me a good
pedagogic order, in proceeding from the more concrete mental aspects
with which we are best acquainted to the so-called elements which we
naturally come to know later by way of abstraction. The opposite order,
of 'building-up' the mind out of its 'units of composition,' has the
merit of expository elegance, and gives a neatly subdivided table of
contents; but it often purchases these advantages at the cost of reality
and truth. I admit that my 'synthetic' order was stumblingly carried
out; but this again was in consequence of what I thought were pedagogic
necessities. On the whole, in spite of my critics, I venture still to
think that the 'unsystematic' form charged upon the book is more
apparent than profound, and that we really gain a more living
understanding of the mind by keeping our attention as long as possible
upon our entire conscious states as they are concretely given to us,
than by the _post-mortem_ study of their comminuted 'elements.' This
last is the study of artificial abstractions, not of natural things.[1]
But whether the critics are right, or I am, on this first point, the
critics are wrong about the relation of the magazine-articles to the
book. With a single exception all the chapters were written for the
book; and then by an after-thought some of them were sent to magazines,
because the completion of the whole work seemed so distant. My lack of
capacity has doubtless been great, but the charge of not having taken
the utmost pains, according to my lights, in the composition of the
volumes, cannot justly be laid at my door.
CONTENTS.
CHAPTER I.
PAGE
INTRODUCTORY 1
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 GENERAL 9
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.
SIGHT 28
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.
HEARING 47
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 PAIN 60
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 MOTION 70
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 BRAIN 78
Embryological sketch, 78. Practical dissection of the sheep's brain, 81.
CHAPTER VIII.
THE FUNCTIONS OF THE BRAIN 91
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 ACTIVITY 120
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.
HABIT 134
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 CONSCIOUSNESS 151
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 SELF 176
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.
ATTENTION 217
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.
CONCEPTION 239
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.
DISCRIMINATION 244
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.
ASSOCIATION 253
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 TIME 280
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.
MEMORY 287
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.
IMAGINATION 302
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.
PERCEPTION 312
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 SPACE 335
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.
REASONING 351
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 MOVEMENT 370
All consciousness is motor, 370. Three classes of movement to which it
leads, 372.
CHAPTER XXIV.
EMOTION 373
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.
INSTINCT 391
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.
WILL 415
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 PHILOSOPHY 461
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.
PSYCHOLOGY.
CHAPTER I.
INTRODUCTORY.
=The definition of Psychology= may be best given in the words of Professor
Ladd, as the _description and explanation of states of consciousness as
such_. By states of consciousness are meant such things as sensations,
desires, emotions, cognitions, reasonings, decisions, volitions, and the
like. Their 'explanation' must of course include the study of their
causes, conditions, and immediate consequences, so far as these can be
ascertained.
=Psychology is to be treated as a natural science= in this book. This
requires a word of commentary. Most thinkers have a faith that at bottom
there is but one Science of all things, and that until all is known, no
one thing can be completely known. Such a science, if realized, would be
Philosophy. Meanwhile it is far from being realized; and instead of it,
we have a lot of beginnings of knowledge made in different places, and
kept separate from each other merely for practical convenience' sake,
until with later growth they may run into one body of Truth. These
provisional beginnings of learning we call 'the Sciences' in the plural.
In order not to be unwieldy, every such science has to stick to its own
arbitrarily-selected problems, and to ignore all others. Every science
thus accepts certain data unquestioningly, leaving it to the other parts
of Philosophy to scrutinize their significance and truth. All the
natural sciences, for example, in spite of the fact that farther
reflection leads to Idealism, assume that a world of matter exists
altogether independently of the perceiving mind. Mechanical Science
assumes this matter to have 'mass' and to exert 'force,' defining these
terms merely phenomenally, and not troubling itself about certain
unintelligibilities which they present on nearer reflection. Motion
similarly is assumed by mechanical science to exist independently of the
mind, in spite of the difficulties involved in the assumption. So
Physics assumes atoms, action at a distance, etc., uncritically;
Chemistry uncritically adopts all the data of Physics; and Physiology
adopts those of Chemistry. Psychology as a natural science deals with
things in the same partial and provisional way. In addition to the
'material world' with all its determinations, which the other sciences
of nature assume, she assumes additional data peculiarly her own, and
leaves it to more developed parts of Philosophy to test their ulterior
significance and truth. These data are--
1. _Thoughts and feelings_, or whatever other names transitory _states
of consciousness_ may be known by.
2. _Knowledge_, by these states of consciousness, of other things. These
things may be material objects and events, or other states of mind. The
material objects may be either near or distant in time and space, and
the states of mind may be those of other people, or of the thinker
himself at some other time.
How one thing _can_ know another is the problem of what is called the
Theory of Knowledge. How such a thing as a 'state of mind' can be at all
is the problem of what has been called Rational, as distinguished from
Empirical, Psychology. The _full_ truth about states of mind cannot be
known until both Theory of Knowledge and Rational Psychology have said
their say. Meanwhile an immense amount of provisional truth about them
can be got together, which will work in with the larger truth and be
interpreted by it when the proper time arrives. Such a provisional body
of propositions about states of mind, and about the cognitions which
they enjoy, is what I mean by Psychology considered as a natural
science. On any ulterior theory of matter, mind, and knowledge, the
facts and laws of Psychology thus understood will have their value. If
critics find that this natural-science point of view cuts things too
arbitrarily short, they must not blame the book which confines itself to
that point of view; rather must they go on themselves to complete it by
their deeper thought. Incomplete statements are often practically
necessary. To go beyond the usual 'scientific' assumptions in the
present case, would require, not a volume, but a shelfful of volumes,
and by the present author such a shelfful could not be written at all.
Let it also be added that =the human mind is all that can be touched upon=
in this book. Although the mental life of lower creatures has been
examined into of late years with some success, we have no space for its
consideration here, and can only allude to its manifestations
incidentally when they throw light upon our own.
=Mental facts cannot be properly studied apart from the physical
environment of which they take cognizance.= The great fault of the older
rational psychology was to set up the soul as an absolute spiritual
being with certain faculties of its own by which the several activities
of remembering, imagining, reasoning, willing, etc., were explained,
almost without reference to the peculiarities of the world with which
these activities deal. But the richer insight of modern days perceives
that our inner faculties are _adapted_ in advance to the features of the
world in which we dwell, adapted, I mean, so as to secure our safety and
prosperity in its midst. Not only are our capacities for forming new
habits, for remembering sequences, and for abstracting general
properties from things and associating their usual consequences with
them, exactly the faculties needed for steering us in this world of
mixed variety and uniformity, but our emotions and instincts are
adapted to very special features of that world. In the main, if a
phenomenon is important for our welfare, it interests and excites us the
first time we come into its presence. Dangerous things fill us with
involuntary fear; poisonous things with distaste; indispensable things
with appetite. Mind and world in short have been evolved together, and
in consequence are something of a mutual fit. The special interactions
between the outer order and the order of consciousness, by which this
harmony, such as it is, may in the course of time have come about, have
been made the subject of many evolutionary speculations, which, though
they cannot so far be said to be conclusive, have at least refreshed and
enriched the whole subject, and brought all sorts of new questions to
the light.
The chief result of all this more modern view is the gradually growing
conviction that =mental life is primarily teleological=; that is to say,
that our various ways of feeling and thinking have grown to be what they
are because of their utility in shaping our _reactions_ on the outer
world. On the whole, few recent formulas have done more service in
psychology than the Spencerian one that the essence of mental life and
bodily life are one, namely, 'the adjustment of inner to outer
relations.' The adjustment is to immediately present objects in lower
animals and in infants. It is to objects more and more remote in time
and space, and inferred by means of more and more complex and exact
processes of reasoning, when the grade of mental development grows more
advanced.
Primarily then, and fundamentally, the mental life is for the sake of
action of a preservative sort. Secondarily and incidentally it does many
other things, and may even, when ill 'adapted,' lead to its possessor's
destruction. Psychology, taken in the widest way, ought to study every
sort of mental activity, the useless and harmful sorts as well as that
which is 'adapted.' But the study of the harmful in mental life has been
made the subject of a special branch called 'Psychiatry'--the science of
insanity--and the study of the useless is made over to 'Æsthetics.'
Æsthetics and Psychiatry will receive no special notice in this book.
=All mental states= (no matter what their character as regards utility may
be) =are followed by bodily activity of some sort.= They lead to
inconspicuous changes in breathing, circulation, general muscular
tension, and glandular or other visceral activity, even if they do not
lead to conspicuous movements of the muscles of voluntary life. Not only
certain particular states of mind, then (such as those called volitions,
for example), but states of mind as such, _all_ states of mind, even
mere thoughts and feelings, are _motor_ in their consequences. This will
be made manifest in detail as our study advances. Meanwhile let it be
set down as one of the fundamental facts of the science with which we
are engaged.
It was said above that the 'conditions' of states of consciousness must
be studied. =The immediate condition of a state of consciousness is an
activity of some sort in the cerebral hemispheres.= This proposition is
supported by so many pathological facts, and laid by physiologists at
the base of so many of their reasonings, that to the medically educated
mind it seems almost axiomatic. It would be hard, however, to give any
short and peremptory proof of the unconditional dependence of mental
action upon neural change. That a general and usual amount of dependence
exists cannot possibly be ignored. One has only to consider how quickly
consciousness may be (so far as we know) abolished by a blow on the
head, by rapid loss of blood, by an epileptic discharge, by a full dose
of alcohol, opium, ether, or nitrous oxide--or how easily it may be
altered in quality by a smaller dose of any of these agents or of
others, or by a fever,--to see how at the mercy of bodily happenings our
spirit is. A little stoppage of the gall-duct, a swallow of cathartic
medicine, a cup of strong coffee at the proper moment, will entirely
overturn for the time a man's views of life. Our moods and resolutions
are more determined by the condition of our circulation than by our
logical grounds. Whether a man shall be a hero or a coward is a matter
of his temporary 'nerves.' In many kinds of insanity, though by no means
in all, distinct alterations of the brain-tissue have been found.
Destruction of certain definite portions of the cerebral hemispheres
involves losses of memory and of acquired motor faculty of quite
determinate sorts, to which we shall revert again under the title of
_aphasias_. Taking all such facts together, the simple and radical
conception dawns upon the mind that mental action may be uniformly and
absolutely a function of brain-action, varying as the latter varies, and
being to the brain-action as effect to cause.
=This conception is the 'working hypothesis' which underlies all the
'physiological psychology' of recent years=, and it will be the working
hypothesis of this book. Taken thus absolutely, it may possibly be too
sweeping a statement of what in reality is only a partial truth. But the
only way to make sure of its unsatisfactoriness is to apply it seriously
to every possible case that can turn up. To work an hypothesis 'for all
it is worth' is the real, and often the only, way to prove its
insufficiency. I shall therefore assume without scruple at the outset
that the uniform correlation of brain-states with mind-states is a law
of nature. The interpretation of the law in detail will best show where
its facilities and where its difficulties lie. To some readers such an
assumption will seem like the most unjustifiable _a priori_ materialism.
In one sense it doubtless is materialism: it puts the Higher at the
mercy of the Lower. But although we affirm that the _coming to pass_ of
thought is a consequence of mechanical laws,--for, according to another
'working hypothesis,' that namely of physiology, the laws of
brain-action are at bottom mechanical laws,--we do not in the least
explain the _nature_ of thought by affirming this dependence, and in
that latter sense our proposition is not materialism. The authors who
most unconditionally affirm the dependence of our thoughts on our brain
to be a fact are often the loudest to insist that the fact is
inexplicable, and that the intimate essence of consciousness can never
be rationally accounted for by any material cause. It will doubtless
take several generations of psychologists to test the hypothesis of
dependence with anything like minuteness. The books which postulate it
will be to some extent on conjectural ground. But the student will
remember that the Sciences constantly have to take these risks, and
habitually advance by zig--zagging from one absolute formula to another
which corrects it by going too far the other way. At present Psychology
is on the materialistic tack, and ought in the interests of ultimate
success to be allowed full headway even by those who are certain she
will never fetch the port without putting down the helm once more. The
only thing that is perfectly certain is that when taken up into the
total body of Philosophy, the formulas of Psychology will appear with a
very different meaning from that which they suggest so long as they are
studied from the point of view of an abstract and truncated 'natural
science,' however practically necessary and indispensable their study
from such a provisional point of view may be.
=The Divisions of Psychology.=--So far as possible, then, we are to study
states of consciousness in correlation with their probable neural
conditions. Now the nervous system is well understood to-day to be
nothing but a machine for receiving impressions and discharging
reactions preservative to the individual and his kind--so much of
physiology the reader will surely know. Anatomically, therefore, the
nervous system falls into three main divisions, comprising--
1) The fibres which carry currents in;
2) The organs of central redirection of them; and
3) The fibres which carry them out.
Functionally, we have sensation, central reflection, and motion, to
correspond to these anatomical divisions. In Psychology we may divide
our work according to a similar scheme, and treat successively of three
fundamental conscious processes and their conditions. The first will be
Sensation; the second will be Cerebration or Intellection; the third
will be the Tendency to Action. Much vagueness results from this
division, but it has practical conveniences for such a book as this, and
they may be allowed to prevail over whatever objections may be urged.