Psychology is the Science of Mental Life,
both of its phenomena and of their conditions. The
phenomena are such things as we call feelings,
desires, cognitions, reasonings, decisions, and the
like; and, superficially considered, their variety and
complexity is such as to leave a chaotic impression
on the observer. The most natural and consequently
the earliest way of unifying the material was, first,
to classify it as well as might be, and, secondly, to
affiliate the diverse mental modes thus found, upon
a simple entity, the personal Soul, of which they are
taken to be so many facultative manifestations.
Now, for instance, the Soul manifests its faculty of
Memory, now of Reasoning, now of Volition, or again
its Imagination or its Appetite. This is the orthodox
'spiritualistic' theory of scholasticism and of
common-sense. Another and a less obvious way of
unifying the chaos is to seek common elements in
the divers mental facts rather than a common agent
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The Principles of Psychology Volume I - William James
behind them, and to explain them constructively by
the various forms of arrangement of these elements,
as one explains houses by stones and bricks. The
'associationist' schools of Herbart in Germany, and
of Hume, the Mills and Bain in Britain, have thus
constructed a psychology without a soul by taking
discrete 'ideas,' faint or vivid, and showing how, by
their cohesions, repulsions, and forms   
succession, 
 of
such things as reminiscences,
perceptions, emotions, volitions, passions, theories,
and all the other furnishings of an individual's mind
may be engendered. The very Self or ego of the
individual comes in this way to be viewed no longer
as the pre-existing source of the representations,
but rather as their last and most complicated fruit.
Now, if we strive rigorously to simplify the
phenomena in either of these ways, we soon
become aware of inadequacies in our method. Any
particular cognition, for example, or recollection, is
accounted for on the soul-theory by being referred
to the spiritual faculties of Cognition or of Memory.
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These faculties themselves are thought of as
absolute properties of the soul; that is, to take the
case of memory, no reason is given why we should
remember a fact as it happened, except that so to
remember it constitutes the essence of our
Recollective Power. We may, as spiritualists, try to
explain our memory's failures and blunders by
secondary causes. But its successes can invoke no
factors save the existence of certain objective things
to be remembered on the one hand, and of our
faculty of memory on the other. When, for instance,
I recall my graduation-day, and drag all its incidents
and emotions up from death's dateless night, no
mechanical cause can explain this process, nor can
any analysis reduce it to lower terms or make its
nature seem other than an ultimate datum, which,
whether we rebel or not at its mysteriousness, must
simply be taken for granted if we are to
psychologize at all. However the associationist may
represent the present ideas as thronging and
arranging themselves, still, the spiritualist insists, he
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The Principles of Psychology Volume I - William James
has in the end to admit that something, be it brain,
be it 'ideas,' be it 'association,' knows past time as
past, and fills it out with this or that event. And
when the spiritualist calls memory an 'irreducible
faculty,' he says no more than this admission of the
associationist already grants.
And yet the admission is far from being a
satisfactory simplification of the concrete facts. For
why should this absolute god-given Faculty retain so
much better the events of yesterday than those of
last year, and, best of all, those   
 of an hour ago?
Why, again, in old age should its grasp of
childhood's events seem firmest? Why should illness
and exhaustion enfeeble it? Why should repeating
an experience strengthen our recollection of it? Why
should drugs, fevers, asphyxia, and excitement
resuscitate things long since forgotten? If we
content ourselves with merely affirming that the
faculty of memory is so peculiarly constituted by
nature as to exhibit just these oddities, we seem
little the better for having invoked it, for our
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The Principles of Psychology Volume I - William James
explanation becomes as complicated as that of the
crude facts with which we started. Moreover there is
something grotesque and irrational in the
supposition that the soul is equipped with
elementary powers of such an ingeniously intricate
sort. Why should our memory cling more easily to
the near thanthe remote? Why should it lose its
grasp of proper sooner than of abstract names?
Such peculiarities seem quite fantastic; and might,
for aught we can see a priori, be the precise
opposites of what they are. Evidently, then, the
faculty does not exist absolutely, but works under
conditions; and the quest of the conditions becomes
the psychologist's most interesting task.
However firmly he may hold to the soul and
her remembering faculty, he must acknowledge that
she never exerts the latter without a cue, and that
something must always precede and remind us of
whatever we are to recollect. "An idea!" says the
associationist, "an idea associated with the
remembered thing; and this explains also why
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The Principles of Psychology Volume I - William James
things repeatedly met with are more easily
recollected, for their associates on the various
occasions furnish so many distinct avenues of
recall." But this does not explain the effects of fever,
exhaustion, hypnotism, old age, and the like. And in
general, the pure associationist's account of our
mental life is almost as bewildering as that of the
pure spiritualist. This multitude of ideas, existing
absolutely, yet clinging together, and weaving an
endless carpet of themselves, like dominoes in
ceaseless change, or the bits of glass in a
kaleidoscope,-whence do they get their fantastic
laws of clinging, and why do they cling in just the
shapes they do?
For this the associationist must introduce the
order of experience in the outer world. The dance of
the ideas is    
a copy, somewhat mutilated and
altered, of the order of phenomena. But the slightest
reflection shows that phenomena have absolutely no
power to influence our ideas until they have first
impressed our senses and our brain. The bare
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The Principles of Psychology Volume I - William James
existence of a past fact is no ground for our
remembering it. Unless we have seen it, or
somehow undergone it, we shall never know of its
having been. The experiences of the body are thus
one of the conditions of the faculty of memory being
what it is. And a very small amount of reflection on
facts shows that one part of the body, namely, the
brain, is the part whose experiences are directly
concerned. If the nervous communication be cut off
between the brain and other parts, the experiences
of those other parts are non-existent for the mind.
The eye is blind, the ear deaf, the hand insensible
and motionless. And conversely, if the brain be
injured, consciousness is abolished or altered, even
although every other organ in the body be ready to
play its normal part. A blow on the head, a sudden
subtraction of blood, the pressure of an apoplectic
hemorrhage, may have the first effect; whilst a very
few ounces of alcohol or grains of opium or
hasheesh, or a whiff of chloroform or nitrous oxide
gas, are sure to have the second. The delirium of
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The Principles of Psychology Volume I - William James
fever, the altered self of insanity, are all due to
foreign matters circulating through the brain, or to
pathological changes in that organ's substance. The
fact that the brain is the one immediate bodily
condition of the mental operations is indeed so
universally admitted nowadays that I need spend no
more time in illustrating it, but will simply postulate
it and pass on. The whole remainder of the book will
be more or less of a proof that the postulate was
correct.
Bodily experiences, therefore, and more
particularly brain-experiences, must take a place
amongst those conditions of the mental life of which
Psychology need take account.