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Xibran? of philosophy 




" Though it can hardly be claimed that 
Bergson has completely solved the extra 
ordinary complex and difficult problem 
of memory and least of all the mystery 
of matter, it may be admitted ungrudg 
ingly that he has clarified the obscurities of 
the former problem to a considerable extent, 
and has, above all, rendered great service 
by the masterly way in which he points out 
the insuperable difficulties of the materi 
alistic position. . . . This excellent trans 
lation." The Quest. 

" Of M. Bergson s three works the pre 
sent is that whuh appeals most to the 
educator because of the excellent treatment 
of the very practical subjects of memory 
and attention. We do not look for a 

final decision of such problems as art 
here dealt wtth, but no one can rise from 
reading this book and retain unchanged 
the vieu s with which he began it. To say 
this of a book of psychometaphysics is to 
say much." Journal of Education. 

"As in the case of the former volume 
the translator of this second volume has 
the author s assistance and approval, and 
the author has also written for it a new 
Introduction, superseding that which ac 
companies the original work. In this 
volume, also, the translators have given 
a number of useful marginal summaries 
and a copious index." Westminster 

By the same Author, uniform with this volume, 10s. 6d. net. 


An Essay on the Immediate Data of Consciousness. 

" A philosopher who can think origin 
ally and write felicitously is a combin 
ation rare enough to justify a careful 
study of his message ; and it is satis 
factory to note that M. Bergson s three 
chief works will soon be all accessible in 
English. We can only hope that the 
rendering of the two remaining volumes 
will be as successful as the clear and 
scholarly version which Mr. Pogson gives 
of his Les Donn6es immediates de la 
conscience. The title Time and Free Will 
has been substituted for the somewhat 
colourless title given by M. Bergson to his 
first book and it indicates accurately the 
chief contents of the volume, mainly a 
discussion of the real nature of time and 
the conclusions drawn by the author there 
from as to the possibility of real freedom. 
The general line of argument is the same 
as that familiar to English readers in 
James Principles of Psychology, but it 
is worked out by Bergson with incom 
parable lucidity and a fulness of treatment 
that make it quite conclusive. It is not 
easy, by any process of summarizing or 
selecting, to convey the real force and 
persuasiveness of M. Bergson s argument. 
The temperate critic may reasonably 
doubt whether he has laid this venerable 
controversy to its final rest, but he will 
not deny that both his admissions and 
contentions go far to clear the air, and 
that many musty idols of the schools 
crumble at his touch." Times. 

" Prof. Bergson otcupies to-day in 
France, and indeed on the Continent, 
something of the samt position as the 
late Prof. William Young occupied 
among English-speaking peoples. Both 
are apostles of the plain man and the 
ordinary consciousness. Both approached 
philosophy proper through experimental 
psychology, but Professor Bergson has 
one special stage in his development which 
gives his work a peculiar interest. He is 
an eminent mathematician and familiar 
with the most abstract types of symbolical 
thought. Prof, Bergson is not an easy 
writer to translate. His ttylt in its 

simplicity and clarity and concentration 
is one of the best that have ever been used 
in tht service of philosophy ; and for a 
succinct French style it is a hard mutter 
to find an English equivalent. Mr. 
Pogson seems to have done his work ad 
mirably, for he has succeeded in being 
always lucid and satisfactory, while re 
taining something of the grace of the 
original." Spectator. 

" The translation reproduces the re 
markable lucidity of thought and express- 
sion that distinguish A/. Bergson s pre 
sentment of a philosophical subject. It 
will be fairly easy for the educated reader 
who has any taste for inquiry into ques 
tions of man s mental life to follow M. 
Bergson s extremely interesting discus 
sions." Saturday Review. 

" The translator of this book has done 
his work thoroughly well. Prof. Berg 
son s French style is lucid enough in its 
own way, but he writes in a highly con 
centrated fashion, having, moreover, a 
line of thought to develop which is apt 
by its sheer unfamiliarity to baffle even the 
most professional of philosophers. In 
the present version the meaning is brought 
out with punctilious exactness as by 
ant who has weighed each word of the 
original, yet the effect of the whole is 
natural and easy. It is indeed no small 
misfortune to the world of letters that the 
rendering of those later works in which 
the Bergsonian doctrine of reality attains 
its full consummation must become the 
task of other hands. . . . It is not necessary 
here to examine in any great detail a book, 
the conclusions of which are as stepping 
stones leading on to the maturer, or at 
any rate, more comprehensive studies 
represented by Matiere et Mcmoire, and 
more notably still that triumph of auda 
cious synthesis, L Evolution Creatrire. 
The present treatise embodies a highly 
compact piece of introspective psychology 
in three chapters, the first two of which 
are intended to terve as a sort of intro 
duction to the first." Athcna iim. 





Authorized Translation by 


FIRST PUBLISHED: January 1911 

KKPRINTED: January 1912 

tl March 1913 

September 1919 

July 1929 

All rights reserved 

FEB ! 5 1347 

in h 


THIS translation of Monsieur Bergson s Matilre 
el Memoire has been made from the fifth edition 
of 1908, and has had the great advantage of 
being revised in proof by the author. Monsieur 
Bergson has also written a new Introduction for 
it, which supersedes that which accompanied the 
original work. 

The translators offer their sincere thanks to 
the author for his invaluable help in these matters 
and for many suggestions made by him while the 
book was in manuscript. 

They beg leave to call the reader s attention 
to the fact that all the marginal notes are peculiar 
to the English edition ; and that, although Mon 
sieur Bergson has been good enough to revise 
them, he is not responsible for their insertion or 
character, since they form no part of his own plan 
for the book. 

N. M. P. 
W. S. P. 


THIS book affirms the reality of spirit and the 
reality of matter, and tries to determine the rela 
tion of the one to the other by the study of a defi 
nite example, that of memory. It is, then, frankly 
dualistic. But, on the other hand, it deals with 
body and mind in such a way as, we hope, to 
lessen greatly, if not to overcome, the theoretical 
difficulties which have always beset dualism, and 
which cause it, though suggested by the immediate 
verdict of consciousness and adopted by common 
sense, to be held in small honour among philoso 

These difficulties are due, for the most part, to 
the conception, now realistic, now idealistic, 
which philosophers have of matter. The aim of 
our first chapter is to show that realism and 
idealism both go too far, that it is a mistake to 
reduce matter to the perception which we have 
of it, a mistake also to make of it a thing able to 
produce in us perceptions, but in itself of another 
nature than they. Matter, in our view, is an 
aggregate of images/ And by image we 
mean a certain existence which is more than that 
which the idealist calls a representation, but less 
than that which the realist calls a thing, an 


existence placed half-way between the thing 
and the representation/ This conception of 
matter is simply that of common sense. It would 
greatly astonish a man unaware of the specula 
tions of philosophy if we told him that the object 
before him, w r hich he sees and touches, exists only 
in his mind and for his mind, or even, more gener 
ally, exists only for mind, as Berkeley held. Such 
a man would always maintain that the object 
exists independently of the consciousness which 
perceives it. But, on the other hand, we should 
astonish him quite as much by telling him that 
the object is entirely different from that which is 
perceived in it, that it has neither the colour as 
cribed to it by the eye, nor the resistance found in 
it by the hand. The colour, the resistance, are, 
for him, in the object : they are not states of our 
mind ; they are part and parcel of an existence 
really independent of our own. For common 
sense, then, the object exists in itself, and, on the 
other hand, the object is, in itself, pictorial, as we 
perceive it : image it is, but a self -existing image. 
This is just the sense in which we use the word 
image in our first chapter. We place ourselves 
at the point of view of a mind unaware of the dis 
putes between philosophers. Such a mind would 
naturally believe that matter exists just as it is 
perceived ; and, since it is perceived as an image, 
the mind would make of it, in itself, an image. 
In a word, we consider matter before the dissocia 
tion which idealism and realism have brought 


about between its existence and its appearance. 
No doubt it has become difficult to avoid this 
dissociation now that philosophers have made it. 
To forget it, however, is what we ask of the reader. 
If, in the course of this first chapter, objections 
arise in his mind against any of the views that we 
put forward, let him ask himself whether these 
objections do not imply his return to one or the 
other of the two points of view above which we 
urge him to rise. 

Philosophy made a great step forward on the 
day when Berkeley proved, as against the me 
chanical philosophers, that the secondary qualities 
of matter have at least as much reality as the 
primary qualities. His mistake lay in believing 
that, for this, it was necessary to place matter 
within the mind, and make it into a pure idea. 
Descartes, no doubt, had put matter too far from 
us when he made it one with geometrical extensity. 
But, in order to bring it nearer to us, there was no 
need to go to the point of making it one with our 
own mind. Because he did go as far as this, 
Berkeley was unable to account for the success of 
physics, and, whereas Descartes had set up the 
mathematical relations between phenomena as 
their very essence, he was obliged to regard the 
mathematical order of the universe as a mere 
accident. So the Kantian criticism became neces 
sary, to show the reason of this mathematical 
order and to give back to our physics a solid found 
ation a task in which, however, it succeeded 


only by limiting the range and value of our senses 
and of our understanding. The criticism of 
Kant, on this point at least, would have been 
unnecessary ; the human mind, in this direction at 
least, would not have been led to limit its own 
range ; metaphysics would not have been sacrificed 
to physics, if philosophy had been content to leave 
matter half way between the place to which 
Descartes had driven it and that to which Berkeley 
drew it back to leave it, in fact, where it is seen 
by common sense. 

There we shall try to see it ourselves. Our 
first chapter defines this way of looking at matter ; 
the last sets forth the consequences of such a view. 
But, as we said before, we treat of matter only in 
so far as it concerns the problem dealt with in our 
second and third chapters, that which is the subject 
of this essay : the problem of the relation between 
soul and body. 

This relation, though it has been a favourite 
theme throughout the history of philosophy, has 
really been very little studied. If we leave on one 
side the theories which are content to state the 
union of soul and body as an irreducible and 
inexplicable fact, and those which speak vaguely 
of the body as an instrument of the soul, there 
remains hardly any other conception of the psycho- 
physiological relation than the hypothesis of- 
epiphenomenalism or that of parallelism, which 
in practice I mean in the interpretation of par 
ticular facts both end in the same conclusions. 


For whether, indeed, thought is regarded as a mere 
function of the brain and the state of consciousness 
as an epiphenomenon of the state of the brain, or 
whether mental states and brain states are held to 
be two versions, in two different languages, of 
one and the same original, in either case it is laid 
down that, could we penetrate into the inside of a 
brain at work and behold the dance of the atoms 
which make up the cortex, and if, on the other 
hand, we possessed the key to psycho-physiology, 
we should know every detail of what is going on in 
the corresponding consciousness. 

This, indeed, is what is most commonly main 
tained by philosophers as well as by men of science. 
Yet it would be well to ask whether the facts, 
when examined without any preconceived idea, 
really suggest an hypothesis of this kind. That 
there is a close connexion between a state of con 
sciousness and the brain we do not dispute. But 
there is also a close connexion between a coat and 
the nail on which it hangs, for, if the nail is pulled 
out, the coat falls to the ground. Shall we say, 
then, that the shape of the nail gives us the shape 
of the coat, or in any way corresponds to it ? 
No more are we entitled to conclude, because the 
physical fact is hung on to a cerebral state, that 
there is any parallelism between the two series 
psychical and physiological. When philosophy 
pleads that the theory of parallelism is borne out 
by the results of positive science, it enters upon an 
unmistakably vicious circle ; for, if science inter- 


prets connexion, which is a fact, as signifying 
parallelism, which is an hypothesis (and an hypo 
thesis to which it is difficult to attach an intelligible 
meaning *), it does so, consciously or unconsciously, 
for reasons of a philosophic order : it is because 
science has been accustomed by a certain type of 
philosophy to believe that there is no hypothesis 
more probable, more in accordance with the 
interests of scientific enquiry. 

Now, as soon as we do, indeed, apply to positive 
facts for such information as may help us to solve 
the problem, we find it is with memory that we have 
to deal. This was to be expected, because mem 
ory we shall try to prove it in the course of this 
work is just the intersection of mind and matter. 
But we may leave out the reason here : no one, at 
any rate, will deny that, among all the facts capable 
of throwing light on the psycho-physiological 
relation, those which concern memory, whether in 
the normal or in the pathological state, hold a 
privileged position. Not only is the evidence here 
extremely abundant (consider the enormous mass 
of observations collected in regard to the various 
kinds of aphasia), but nowhere else have anatomy, 
physiology and psychology been able to lend each 
other such valuable aid. Any one who approaches, 
without preconceived idea and on the firm ground 
of facts, the classical problem of the relations Of 

1 \Ve have laid stress on this particular point in an essay 
on " Le paralogisme psycho-physiologic/ue " (Revue de Mela- 
physique et de Morale, Nov., 1904). 


soul and body, will soon see this problem as 
centering upon the subject of memory, and even 
more particularly upon the memory of words : it 
is from this quarter, undoubtedly, that will come 
the light which will illumine the obscurer parts of 
the problem. 

The reader will see how we try to solve it. Speak 
ing generally, the psychical state seems to us to be, 
in most cases, immensely wider than the cerebral 
state. I mean that the brain state indicates only 
a very small part of the mental state, that part 
which is capable of translating itself into move 
ments of locomotion. Take a complex thought 
which unrolls itself in a chain of abstract reasoning. 
This thought is accompanied by images, that are 
at least nascent. And these images themselves 
are not pictured in consciousness without some 
foreshadowing, in the form of a sketch or a ten 
dency, of the movements by which these images 
would be acted or played in space, would, that is 
to say, impress particular attitudes upon the body, 
and set free all that they implicitly contain of 
spatial movement. Now, of all the thought which 
is unrolling, this, in our view, is what the cerebral 
state indicates at every moment. He who could 
penetrate into the interior of a brain and see what 
happens there, would probably obtain full details 
of these sketched-out, or prepared, movements ; 
there is no proof that he would learn anything else. 
Were he endowed with a superhuman intellect, 
did he possess the key to psycho-physiology, he 


would know no more of what is going on in the 
corresponding consciousness than we should know 
of a play from the comings and goings of the actors 
upon the stage. 

That is to say, the relation of the mental to the 
cerebral is not a constant, any more than it is a 
simple, relation. According to the nature of the 
play that is being acted, the movements of the 
players tell us more or less about it : nearly every 
thing, if it is a pantomime ; next to nothing, if it 
is a delicate comedy. Thus our cerebral state 
contains more or less of our mental state in the 
measure that we reel off our psychic life into 
action or wind it up into pure knowledge. 

There are then, in short, divers tones of mental 
life, or, in other words, our psychic life may be 
lived at different heights, now nearer to action, 
now further removed from it, according to the 
degree of our attention to life. Here we have one 
of the ruling ideas of this book-the idea, indeed, 
which served as the starting-point of our enquiry. 
That which is usually held to be a greater complex 
ity of the psychical state appears to us, from our 
point of view, to be a greater dilatation of the 
whole personality, which, normally narrowed down 
by action, expands with the unscrewing of the 
vice in which it has allowed itself to be squeezed, 
and, always whole and undivided, spreads itself 
over a wider and wider surface. That which is 
commonly held to be a disturbance of the psychic 
life itself, an inward disorder, a disease of the per- 


sonality, appears to us, from our point of view, 
to be an unloosing or a breaking of the tie which 
binds this psychic life to its motor accompaniment, 
a weakening or an impairing of our attention to 
outward life. This opinion, as also that which de 
nies the localization of the memory-images of words 
and explains aphasia quite otherwise than by such 
localization, was considered paradoxical at the 
date of the first publication of the present work 
(1896). It will appear much less so now. The 
conception of aphasia then classical, universally 
admitted, believed to be unshakeable, has been 
considerably shaken in the last few years, chiefly 
by reasons of an anatomical order, but partly also 
by reasons of the same kind as those which we then 
advanced. 1 And the profound and original study 
of neuroses made by Professor Pierre Janet has 
led him, of late years, to explain all psychasthenic 
forms of disease by these same considerations of 
psychic tension and of attention to reality which 
were then presumed to be metaphysical. 2 

In truth, it was not altogether a mistake to call 
them by that name. Without denying to psycho 
logy, any more than to metaphysics, the right to 
make itself into an independent science, we believe 
that each of these two sciences should set problems 
to the other and can, in a measure, help it to solve 

1 F. Moutier, L Aphaste de Broca, Paris, 1908 ; especially 
Chapter VII. Cf. the work of Professor Pierre Marie. 

2 P. Janet, Les obsessions et la Psychasthenie, Paris, 1903 ; 
in particular pp. 474-502. 


them. How should it be otherwise, if psychology 
has for its object the study of the human mind 
working for practical utility, and if metaphysics is 
but this same mind striving to transcend the con 
ditions of useful action and to come back to itself 
as to a pure creative energy ? Many problems 
which appear foreign to each other as long as we 
are bound by the letter of the terms in which 
these two sciences state them, are seen to be very 
near akin and to be able to solve each other when 
we thus penetrate into their inner meaning. We 
little thought, at the beginning of our enquiry, 
that there could be any connexion between the 
analytical study of memory and the question, 
which are debated between realists and idealistss 
or between mechanists and dynamists, with regard 
to the existence or the essence of matter. Yet this 
connexion is real, it is even intimate ; and, if we 
take it into account, a cardinal metaphysical 
problem is carried into the open field of observa 
tion, where it may be solved progressively, instead 
of for ever giving rise to fresh disputes of the 
schools within the closed lists of pure dialectic. 
The complexity of some parts of the present work 
is due to the inevitable dovetailing of problems 
which results from approaching philosophy in such 
a way. But through this complexity, which is 
due to the complexity of reality itself, we believe 
that the reader will find his way if he keeps a fast 
hold on the two principles which we have used as 
a clue throughout our own researches. The first 


is that in psychological analysis we must never 
forget the utilitarian character of our mental func 
tions, which are essentially turned towards action. 
The second is that the habits formed in action find 
their way up to the sphere of speculation, where 
they create fictitious problems, and that meta 
physics must begin by dispersing this artificial 


October, 1910, 



[NTRODUCTION vii-xvii 


DOES . 1-85 

Real action and virtual action, i 8 ; Representation, 
814; Realism and Idealism, 1417; The choice of 
images, 17-35 ; Relation between representation and 
action, 3545 ; The image and reality, 4551 ; The 
image and affective sensation, 5155 ; Nature of affective 
sensation, 55-59; The image, apart from sensation, 
59-62 ; Natural extension of images, 62-69 ; Pure 
perception, 69-73 : Approach to the problem of matter, 
73-81 ; Memory, 81-85. 



BRAIN ........ 86-169 

The two forms of memory, 86-105 ; Movements and 
Recollections, 105118; Recollections and movements, 
118-145 Realization of memories, 145-169. 



MIND ........ 170-232 

Pure memory, 170176 ; What the present is, 176-181 ; 
The unconscious, 181-189; Existence, 189191; Rela 
tion of past and present, 191-200 ; Memory and general 



ideas, 201212; The Association of Ideas, 212217; 
The plane of action and the plane of dream, 217-220; 
The different planes of consciousness, 220225 ; Attention 
to life, 225226 ; Mental equilibrium, 227-230 ; The 
Office of the body, 231-232. 



The problem of dualism, 233238 ; Description of the 
Method, 238245 ; Indivisibility of movement, 246253 ; 
Real movement, 254259 ; Perception and matter, 
259-267 ; Duration and tension, 267-277 ; Extensity 
and sxtension, 277-291 ; Soul and body, 291298. 


INDEX r ....... 333-339 



WE will assume for the moment that we know 
nothing of theories of matter and theories of 
spirit, nothing of the discussions as to the reality 
or ideality of the external world. Here I am ir 
the presence of images, in the vaguest sense of 
the word, images perceived when my senses 
are opened to them, unperceived when they are 
closed. All these images act and react upon 
one another in all their elementary parts 
according to constant laws which I call laws of 
nature, and, as a perfect knowledge of these laws 
would probably allow us to calculate and to fore 
see what will happen in each of these images, the 
future of the images must be contained in their 
present and will add to them nothing new. 

Yet there is one of them which is distinct from 

all the others, in that I do not know it only from 

without by perceptions, but from within 

The nniqne / .f . 

place and by affections : it is my body. I exa- 

function o! . . . 

the living mine the conditions in which these 


affections are produced : I find that 
they always interpose themselves between the ex 
citations that I receive from without and the move- 


ments which I am about to execute, as though 
they had some undefined influence on the final 
issue. I pass in review my different affections : 
it seems to me that each of them contains, after 
its kind, an invitation to act, with at the same 
time leave to wait and even to do nothing. I 
look closer : I find movements begun, but not 
executed, the indication of a more or less useful 
decision, but not that constraint which precludes 
choice. I call up, I compare my recollections : 
I remember that everywhere, in the organic 
world, I have thought I saw this same sensibility 
appear at the very moment when nature, having 
conferred upon the living being the power of 
mobility in space, gives warning to the species, 
by means of sensation, of the general dangers 
which threaten it, leaving to the individuals the 
precautions necessary for escaping from them. 
Lastly, I interrogate my consciousness as to the 
part which it plays in affection : consciousness 
replies that it is present indeed, in the form of 
feeling or of sensation, at all the steps in which I 
believe that I take the initiative, and that it 
fades and disappears as soon as my activity, by 
becoming automatic, shows that consciousness 
is no longer needed. Therefore, either all these 
appearances are deceptive, or the act in which 
the affective state issues is not one of those 
which might be rigorously deduced from ante 
cedent phenomena, as a movement from a move 
ment ; and hence it really adds something new to 


the universe and to its history. Let us hold to 
the appearances ; I will formulate purely and 
simply what I feel and what I see : All seems 
to take place as if, in this aggregate of images 
which I call the universe, nothing really new could 
happen except through the medium of certain par 
ticular images, the type of which is furnished me 
by my body. 

I pass now to the study, in bodies similar to 
my own, of the structure of that particular 
image which I call my body. I perceive afferent 
nerves which transmit a disturbance to the nerve 
centres, then efferent nerves which start from the 
centre, conduct the disturbance to the periphery, 
and set in motion parts of the body or the body 
as a whole. I question the physiologist and the 
psychologist as to the purpose of both kinds. 
They answer that as the centrifugal movements 
of the nervous system can call forth a movement 
of the body or of parts of the body, so the centri 
petal movements, or at least some of them, give 
birth to the representation * of the external world. 
What are we to think of this ? 

The afferent nerves are images, the brain is an 
image, the disturbance travelling through the 
yetthebrainig sensory nerves and propagated in the 

amonToS 6 brain is an ima g e to - If the ima g6 

images. which I term cerebral disturbance really 

1 The word representation is used throughout this book 
in the French sense, as meaning a mental picture, which 
mental picture is very o* f en perception. (Translators note.) 


begot external images, it would contain them in 
one way or another, and the representation of the 
whole material universe would be implied in that 
of this molecular movement. Now to state this 
proposition is enough to show its absurdity. The 
brain is part of the material world ; the material 
world is not part of the brain. Eliminate the 
image which bears the name material world, and 
you destroy at the same time the brain and the 
cerebral disturbance which are parts of it. Sup 
pose, on the contrary, that these two images, the 
brain and the cerebral disturbance, vanish : ex 
hypotihesi you efface only these, that is to say very 
little, an insignificant detail from an immense 
picture. The picture in its totality, that is to say 
the whole universe, remains. To make of the 
brain the condition on which the whole image 
depends is in truth a contradiction in terms, since 
the brain is by hypothesis a part of this image. 
Neither nerves nor nerve centres can, then, con 
dition the image of the universe. 

Let us consider this last point. Here are 
external images, then my body, and, lastly, the 
The body is a changes brought about by my body in 
action it ^he surrounding images. I see plainly 
rettS? and h w externa -l images influence the image 
movements. fa^ j ca u m y body : they transmit 

movement to it. And I also see how this bod) 
influences external images : it gives back move 
ment to them. My body is, then, in the aggre 
gate of the material world, an image which 


acts like other images, receiving and giving back 
movement, with, perhaps, this difference only, 
that my body appears to choose, within certain 
limits, the manner in which it shall restore what 
it receives. But how could my body in general, 
and my nervous system in particular, beget the 
whole or a part of my representation of the uni 
verse ? You may say that my body is matter, 
or that it is an image : the word is of no importance. 
If it is matter, it is a part of the material 
world ; and the material world, consequently, exists 
around it and without it. If it is an image, that 
image can give but what has been put into it, 
and since it is, by hypothesis, the image of my 
body only, it would be absurd to expect to get 
from it that of the whole universe. My body, 
an object destined to move other objects, is, then, a 
centre of action ; it cannot give birth to a representa 

But if my body is an object capable of exercis 
ing a genuine and therefore a new action upon 
so the body ^ e surrounding objects, it must occupy 
prMieged a privileged position in regard to them. 
providing for ^ s a m ^ G ^Y mia g e influences other 
oi 8 choiS ise i ma es m a manner which is determined, 
Jo3e and even calculable, through what are 
reactions. called the laws of nature. As it has 
not to choose, so neither has it any need to ex 
plore the region round about it, nor to try its 
hand at several merely eventual actions. The 


necessary action will take place automatically, 
when its hour strikes. But I have supposed that 
the office of the image which I call my body was 
to exercise on other images a real influence, and, 
consequently, to decide which step to take among 
several which are all materially possible. And 
since these steps are probably suggested to it by 
the greater or less advantage which it can derive 
from the surrounding images, these images must 
display in some way, upon the aspect which they 
present to my body, the profit which my body 
can gain from them. In fact, I note that the size, 
shape, even the colour, of external objects is 
modified according as my body approaches or 
recedes from them ; that the strength of an 
odour, the intensity of a sound, increases or di 
minishes with distance ; finally, that this very 
distance represents, above all, the measure in 
which surrounding bodies are insured, in some 
sort, against the immediate action of my body. 
In the degree that my horizon widens, the images 
which surround me seem to be painted upon a 
more uniform background and become to me more 
indifferent. The more I narrow this horizon, the 
more the objects which it circumscribes space 
themselves out distinctly according to the greater 
or less ease with which my body can touch and 
move them. They send back, then, to my body, 
as would a mirror, its eventual influence ; they 
take rank in an order corresponding to the 
growing or decreasing powers of my body. The 


objects which surround my body reflect its possible 
action upon them. 

I will now, without touching the other images, 

modify slightly that image which I call my body. 

In this image I cut asunder, in thought, 

point to all the afferent nerves of the cerebro- 


possible spinal system. What will happen ? 
A few cuts with the scalpel have 
severed a few bundles of fibres : the rest of the 
universe, and even the rest of my body, remain 
what they were before. The change effected is 
therefore insignificant. As a matter of fact, my 
perception has entirely vanished. Let us con 
sider more closely what has just occurred. 
Here are the images which compose the universe 
in general, then those which are near to my body, 
and finally my body itself. In this last image 
the habitual office of the centripetal nerves is 
to transmit movements to the brain and to 
the cord ; the centrifugal nerves send back 
this movement to the periphery. Section of the 
centripetal nerves can therefore produce only 
one intelligible effect ; that is, to interrupt the 
current which goes from the periphery to the 
periphery by way of the centre, and, conse 
quently, to make it impossible for my body to 
extract, from among all the things which surround 
it, the quantity and quality of movement neces 
sary in order to act upon them. Here is some 
thing which concerns action, and action alone. 


Yet it is my perception which has vanished. 
What does this mean, if not that my perception 
displays, in the midst of the image world, as 
would their outward reflexion or shadow, the 
eventual or possible actions of my body ? Now 
the system of images in which the scalpel has 
effected only an insignificant change is what is 
generally called the material world ; and, on the 
other hand, that which has just vanished is my 
perception of matter. Whence, provisionally, 
these two definitions : / call matter the aggregate 
of images, and perception of matter these same 
images referred to the eventual action of one particular 
image, my body. 

Let us go more deeply into this reference. 
I consider my body, with its centripetal and cen- 
The brain IB trifugal nerves, with its nerve centres. 
wi"h e motor ^ know that external objects make in 
SSth^onsSoM t^ 6 a ff eren t nerves a disturbance which 
perception, passes onward to the centres, that 
the centres are the theatre of very varied molecular 
movements, and that these movements depend 
on the nature and position of the objects. Change 
the objects, or modify their relation to my body, 
and everything is changed in the interior move 
ments of my perceptive centres. But every 
thing is also changed in my perception. My 
perception is, then, a function of these molecular 
movements ; it depends upon them. But how 
does it depend upon them ? It will perhaps be 


said that it translates them, and that, in the main, 
I represent to myself nothing but the molecular 
movements of cerebral substance. But how 
should this have any meaning, since the image 
of the nervous system and of its internal 
movements is only, by hypothesis, that of a cer 
tain material object, whereas I represent to 
myself the whole material universe ? It is true 
that many philosophers attempt to evade the diffi 
culty. They show us a brain, analogous in its 
essence to the rest of the material universe, an 
image, consequently, if the universe is an image. 
Then, since they want the internal move 
ments of this brain to create or determine the 
representation of the whole material world an 
image infinitely greater than that of the cere 
bral vibrations they maintain that these mole 
cular movements, and movement in general, 
are not images like others, but something 
which is either more or less than an image 
in any case is of another nature than an image 
and from which representation will issue as by 
miracle. Thus matter is made into something 
radically different from representation, something 
of which, consequently, we have no image ; over 
against it they place a consciousness empty of 
images, of which we are unable to form any idea ; 
lastly, to fill consciousness, they invent an incom 
prehensible action of this formless matter upon 
this matterless thought. But the truth is that 
the movements of matter are very clear, regarded 


as images, and that there is no need to look in 
movement for anything more than what we see 
in it. The sole difficulty would consist in bring 
ing forth from these very particular images the 
infinite variety of representations ; but why seek 
to do so, since we all agree that the cerebral 
vibrations are contained in the material world, 
and that these images, consequently, are only a 
part of the representation ? What then are these 
movements, and what part do these particular 
images play in the representation of the whole ? 
The answer is obvious : they are, within my 
body, the movements intended to prepare, while 
beginning it, the reaction of my body to the action 
of external objects. Images themselves, they 
cannot create images ; but they indicate at each 
moment, like a compass that is being moved 
about, the position of a certain given image, 
my body, in relation to the surrounding images. 
In the totality of representation they are very 
little ; but they are of capital importance for 
that part of representation which I call my 
body, since they foreshadow at each successive 
moment its virtual acts. There is then only a 
difference of degree there can be no difference in 
kind between what is called the perceptive 
faculty of the brain and the reflex functions .of 
the spinal cord. The cord transforms into move 
ments the stimulation received ; the brain prolongs 
it into reactions which are merely nascent ; 
but, in the one case as in the other, the function 


of the nerve substance is to conduct, to coordin 
ate or to inhibit movements. How then does it 
come about that my perception of the universe 
appears to depend upon the internal movements 
of the cerebral substance, to change when they 
vary, and to vanish when they cease ? 

The difficulty of this problem is mainly due to 
the fact that the grey matter and its modifications 
The brain are regarded as things which are suffi- 
oannot cfeSe" c i en t to themselves and might be isolated 
images. from the rest of the universe. Materia 
lists and dualists are fundamentally agreed on 
this point. They consider certain molecular move 
ments of the cerebral matter apart : then, some 
see in our conscious perception a phosphorescence 
which follows these movements and illuminates 
their track ; for others, our perceptions succeed 
each other like an unwinding scroll in a conscious 
ness which expresses continuously, in its own way, 
the molecular vibrations of the cortical sub 
stance : in the one case, as in the other, our per 
ception is supposed to translate or to picture the 
states of our nervous system. But is it possible 
to conceive the nervous system as living apart 
from the organism which nourishes it, from the 
atmosphere in which the organism breathes, from 
the earth which that atmosphere envelopes, from 
the sun round which the earth revolves ? More 
generally, does not the fiction of an isolated 
material object imply a kind of absurdity, since 
this object borrows its physical properties from 


the relations which it maintains with all others, 
and owes each of its determinations, and conse 
quently its very existence, to the place which it 
occupies in the universe as a whole ? Let us no 
longer say, then,that our perceptions depend simply 
upon the molecular movements of the cerebral 
mass. We must say rather that they vary with 
them, but that these movements themselves 
remain inseparably bound up with the rest of the 
material world. The question, then, is not only 
how our perceptions are connected with the 
modifications of the grey matter. The problem 
widens, and can also be put in much clearer terms. 
It might be stated as follows : Here is a 
system of images which I term my perception 
of the universe, and which may be entirely 
images altered by a very slight change in 
fwo^stems, a cei "tain privileged image, my body. 
tS c2SSou d This image occupies the centre ; by it 
ness. a i} t^ others are conditioned ; at each 

of its movements everything changes, as though 
by a turn of a kaleidoscope. Here, on the other 
hand, are the same images, but referred each one 
to itself ; influencing each other no doubt, but 
in such a manner that the effect is always in pro 
portion to the cause : this is what I term the 
universe. The question is : how can these two 
systems co-exist, and why are the same images 
relatively invariable in the universe, and infinitely 
variable in perception ? The problem at issue 
between realism and idealism, perhaps even be- 


tween materialism and spiritualism, should be 
stated, then, it seems to us, in the following 
terms : How is it that the same images can belong at 
the same time to two different systems, the one in 
which each image varies for itself and in the well- 
defined measure that it is patient of the real action of 
surrounding images, the other in which all change 
for a single image, and in the varying measure that 
they reflect the eventual action of this privileged 
image ? 

Every image is within certain images and with 
out others ; but of the aggregate of images we 
cannot say that it is within us or without us, since 
interiority and exteriority are only relations 
among images. To ask whether the universe 
exists only in our thought, or outside of our 
thought, is to put the problem in terms that are 
insoluble, even if we suppose them to be intelli 
gible ; it is to condemn ourselves to a barren 
discussion, in which the terms thought, being, 
universe, will always be taken on either hand in 
entirely different senses. To settle the matter, 
we must first find a common ground on which 
combatants may meet ; and since on both sides it 
is agreed that we can only grasp things in the 
form of images, we must state the problem in 
terms of images, and of images alone. Now 
no philosophical doctrine denies that the same 
images can enter at the same time into two dis 
tinct systems, one belonging to science, wherein 
each image, related only to itself, possesses an 


absolute value ; and the other, the world of con 
sciousness, wherein all the images depend on a 
central image, our body, the variations of which 
they follow. The question raised between realism 
and idealism then becomes quite clear : what are 
the relations which these two systems of images 
maintain with each other ? And it is easy to see 
that subjective idealism consists in deriving the 
first system from the second, materialistic realism 
in deriving the second from the first. 

The realist starts, in fact, from the universe, 
that is to say from an aggregate of images gov 
erned, as to their mutual relations, by 
realism nor fixed laws, in which effects are in strict 
able to proportion to their causes, and of which 
there are two the character is an absence of centre, all 
the images unfolding on one and the 
same plane indefinitely prolonged. But he is at 
once bound to recognize that, besides this system, 
there are perceptions, that is to say, systems in 
which these same images seem to depend on a single 
one among them, around which they range them 
selves on different planes, so as to be wholly 
transformed by the slightest modification of this 
central image. Now this perception is just what 
the idealist starts from : in the system of images 
which he adopts there is a privileged image, )ris 
body, by which the other images are conditioned. 
But as soon as he attempts to connect the present 
with the past and to foretell the future, he is 
obliged to abandon this central position, to replace 


all the images on the same plane, to suppose that 
they no longer vary for him, but for themselves ; 
and to treat them as though they made part of a 
system in which every change gives the exact 
measure of its cause. On this condition alone a 
science of the universe becomes possible ; and, 
since this science exists, since it succeeds in fore 
seeing the future, its fundamental hypothesis can 
not be arbitrary. The first system alone is given 
to present experience ; but we believe in the 
second, if only because we affirm the continuity 
of the past, present, and future. Thus in idealism, 
as in realism, we posit one of the two systems and 
seek to deduce the other from it. 

But in this deduction neither realism nor ideal 
ism can succeed, because neither of the two systems 
of images is implied in the other, and each of them 
is sufficient to itself. If you posit the system 
of images which has no centre, and in which each 
element possesses its absolute dimensions and 
value, I see no reason why to this system should 
accrue a second, in which each image has an 
undetermined value, subject to all the vicissi 
tudes of a central image. You must then, to 
engender perception, conjure up some deus ex 
machina, such as the materialistic hypothesis of 
the epiphenomenal consciousness, whereby you 
choose, among all the images that vary absolutely 
and that you posited to begin with, the one which 
we term our brain, --conferring on the internal 
states of this image the singular and inexplicable 


privilege of adding to itself a reproduction, this 
time relative and variable, of all the others. It 
is true that you afterwards pretend to attach no 
importance to this representation, to see in it a 
mere phosphorescence which the cerebral vibrations 
leave behind them : as if the cerebral matter and 
cerebral vibrations, set in the images which com 
pose this representation, could be of another nature 
than they ! All realism is thus bound to make per 
ception an accident, and consequently a mystery. 
But, inversely, if you posit a system of unstable 
images disposed about a privileged centre, and 
profoundly modified by trifling displacements of 
this centre, you begin by excluding the order of 
nature, that order which is indifferent to the point 
at which we take our stand and to the particular 
end from which we begin. You will have to 
bring back this order by conjuring up in your turn 
a deus ex machina ; I mean that you will have to 
assume, by an arbitrary hypothesis, some sort of 
pre-established harmony between things and 
mind, or, at least (to use Kant s terms), between 
sense and understanding. It is science now that 
will become an accident, and its success a mys 
tery. You cannot, then, deduce the first system 
of images from the second, nor the second from 
the first ; and these two antagonistic doctrines, 
realism and idealism, as soon as they decide to 
enter the same lists, hurl themselves from opposite 
directions against the same obstacle. 

If we now look closely at the two doctrines, 


we shall discover in them a common postulate, 
which we may formulate thus : per- 

Because they 777 . 7 . * * 

both imply an cefition has a wholly speculative interest; 

erroneous . . , _.. . , , . 

postulate, it is pure knowledge. The whole dis- 

viz.,that . * J 

perception cussion turns upon the importance to be 

has merely a ., , * , , , 

speculative attnbuted to this knowledge as com 
pared with scientific knowledge. The 
one doctrine starts from the order required by 
science, and sees in perception only a confused and 
provisional science. The other puts perception 
in the first place, erects it into an absolute, and 
then holds science to be a symbolic expression of 
the real. But, for both parties, to perceive means 
above all to know. 

Now it is just this postulate that we dispute. 
Even the most superficial examination of the 
structure of the nervous system in the animal 
series gives it the lie. And it is not possible 
to accept it without profoundly obscuring the 
threefold problem of matter, consciousness, and 
their relation. 

For if we follow, step by step, the progress of 

external perception from the monera to the higher 

vertebrates, we find that living matter, 

But facts . 

reaiiy suggest even as a simple mass of protoplasm, is 

the opposite ,,..,, , ., 

view. already irritable and contractile, that 


bom the it is open to the influence of external 

structure and . 

evolution of stimulation, and answers to it by 
mechanical, physical, and chemical re 
actions. As we rise in the organic series, we find 
a division of physiological labour. Nerve cells 


appear, are diversified, tend to group themselves 
into a system; at the same time, the animal 
reacts by more varied movements to external 
stimulation. But even when the stimulation re 
ceived is not at once prolonged into movement, it 
appears merely to await its occasion ; and the same 
impression, which makes the organism aware of 
changes in the environment, determines it or pre 
pares it to adapt itself to them. No doubt there 
is in the higher vertebrates a radical distinction 
between pure automatism, of which the seat is 
mainly in the spinal cord, and voluntary activity, 
which requires the intervention of the brain. It 
might be imagined that the impression received, 
instead of expanding into more movements, 
spiritualizes itself into consciousness. But as soon 
as we compare the structure of the spinal cord with 
that of the brain, we are bound to infer that there 
is merely a difference of complication, and not a 
difference in kind, between the functions of the 
brain and the reflex activity of the medullary 
system. For what takes place in reflex action ? 
The centripetal movement communicated by the 
stimulus is reflected at once, by the intermediary of 
the nerve centres of the spinal cord, in a centrifugal 
movement determining a muscular contraction. 
In what, on the other hand, does the function of 
the cerebral system consist ? The peripheral excita 
tion, instead of proceeding directly to the motor- 
cells of the spinal cord and impressing on the muscle 
a necessary contraction, mounts first to the brain, 


and then descends again to the very same motor 
cells of the spinal cord which intervened in the reflex 
action. Now what has it gained by this round 
about course, and what did it seek in the so-called 
sensory cells of the cerebral cortex ? I do not un 
derstand, I shall never understand, that it draws 
thence a miraculous power of changing itself into 
a representation of things ; and moreover, I hold 
this hypothesis to be useless, as will shortly ap 
pear. But what I do see clearly is that the cells of 
the various regions of the cortex which are termed 
sensory, cells interposed between the terminal 
branches of the centripetal fibres and the motor 
cells of the Rolandic area, allow the stimulation 
received to reach at will this or that motor mechan 
ism of the spinal cord, and so to choose its effect. 
The more these intercalated cells are multiplied 
and the more they project amoeboid prolonga 
tions which are probably capable of approaching 
each other in various ways, the more numerous 
and more varied will be the paths capable of 
opening to one and the same disturbance from the 
periphery, and, consequently, the more systems 
of movements will there be among which one and 
the same stimulation will allow of choice. In our 
opinion, then, the brain is no more than a kind of 
central telephonic exchange : its office is to allow 
communication, or to delay it. It adds nothing 
to what it receives ; but, as all the organs of 
perception send it to their ultimate prolongations, 
and as all the motor mechanisms of the spinal 


cord and of the medulla oblongata have in it their 
accredited representatives, it really constitutes 
a centre, where the peripheral excitation gets into 
relation with this or that motor mechanism, chosen 
and no longer prescribed. On the other hand, as 
a great multitude of motor tracks can open simul 
taneously in this substance to one and the same 
excitation from the periphery, this disturbance may 
subdivide to any extent, and consequently dissipate 
itself in innumerable motor reactions which are 
merely nascent. Hence the office of the brain is 
sometimes to conduct the movement received to a 
chosen organ of reaction, and sometimes to open to 
this movement the totality of the motor tracks, so 
that it may manifest there all the potential reactions 
with which it is charged, and may divide and so 
disperse. In other words, the brain appears to us 
to be an instrument of analysis in regard to the 
movement received, and an instrument of selec 
tion in regard to the movement executed. But, 
in the one case as in the other, its office is limited 
to the transmission and division of movement. 
And no more in the higher centres of the cortex 
than in the spinal cord do the nervous elements 
work with a view to knowledge : they do but 
indicate a number of possible actions at once, or 
organize one of them. 

That is to say that the nervous system is in no 
sense an apparatus which may serve to fabricate, 
or even to prepare, representations. Its function is 
to receive stimulation, to pro vide motor apparatus, 


and to present the largest possible number of these 
apparatuses to a given stimulus. The more it 
develops, the more numerous and the more 
distant are the points of space which it brings into 
relation with ever more complex motor mechan 
isms. In this way the scope which it allows to our 
action enlarges : its growing perfection consists 
in nothing else. But if the nervous system is 
thus constructed, from one end of the animal series 
to the other, in view of an action which is less and 
less necessary, must we not think that perception, 
of which the progress is regulated by that of the 
nervous system, is also entirely directed towards 
action, and not towards pure knowledge ? And, if 
this be so, is not the growing richness of this 
perception likely to symbolize the wider range of 
indetermination left to the choice of the living 
being in its conduct with regard to things ? Let 
us start, then, from this indetermination as from 
the true principle, and try whether we cannot deduce 
from it the possibility, and even the necessity, of 
conscious perception. In other words, let us posit 
that system of closely-linked images which we call 
the material world, and imagine here and there, 
within the system, centres of real action, represented 
by living matter : what we mean to prove is 
that there must be, ranged round each one of these 
centres, images that are subordinated to its posi 
tion and variable with it ; that conscious percep 
tion is bound to occur, and that, moreover, it is 
possible to understand how it arises. 


We note, in the first place, that a strict law con 
nects the amount of conscious perception with the 
intensity of action at the disposal of the 
star7 e fr?m s the living being. If our hypothesis is well 
founded, this perception appears at the 
precise moment when a stimulation re- 
ceived by matter is not prolonged into a 
necessary action. In the case of a rudi 
mentary organism, it is true that immediate contact 
with the object which interests it is necessary to pro 
duce the stimulation, and that reaction can then 
hardly be delayed. Thus, in the lower organ 
isms, touch is active and passive at one and the 
same time, enabling them to recognize their prey and 
seize it, to feel a danger and make the effort to 
avoid it. The various prolongations of the pro 
tozoa, the ambulacra of the echinodermata, are 
organs of movement as well as of tactile percep 
tion ; the stinging apparatus of the coelenterata is 
an instrument of perception as well as a means 
of defence. In a word, the more immediate the 
reaction is compelled to be, the more must percep 
tion resemble a mere contact ; and the complete 
process of perception and of reaction can then 
hardly be distinguished from a mechanical impul 
sion followed by a necessary movement. But in 
the measure that the reaction becomes more un 
certain, and allows more room for suspense, 
does the distance increase at which the animal 
is sensible of the action of that which interests it. 
By sight, by hearing, it enters into relation with an 


ever greater number of things, and is subject to more 
and more distant influences ; and, whether these 
objects promise an advantage or threaten a 
danger, both promises and threats defer the date 
of their fulfilment. The degree of independence 
of which a living being is master, or, as we shall 
say, the zone of indetermination which surrounds 
its activity, allows, then, of an a priori estimate of 
the number and the distance of the things with 
which it is in relation. Whatever this relation 
may be, whatever be the inner nature of percep 
tion, we can affirm that its amplitude gives the 
exact measure of the indetermination of the act 
which is to follow. So that we can formulate 
this law : perception is master of space in the exact 
measure in which action is master of time. 

But why does this relation of the organism to 
more or less distant objects take the particular form 
what then f conscious perception ? We have 
Sonsdous-* examined what takes place in the or- 
p?eiiLinary ganized body, we have seen movements 
hmts - transmitted or inhibited, metamor 

phosed into accomplished actions or broken up 
into nascent actions. These movements appear 
to us to concern action, and action alone ; they 
remain absolutely foreign to the process of repre 
sentation. We then considered action itself, and 
the indetermination which surrounds it and is 
implied in the structure of the nervous system, 
an indetermination to which this system seems 
to point much more than to representation. 


From this indetermination, accepted as a fact, 
we have been able to infer the necessity 
of a perception, that is to say, of a variable 
relation between the living being and the more or 
less distant influence of the objects which interest 
it. How is it that this perception is consciousness, 
and why does everything happen as if this con 
sciousness were born of the internal movements of 
the cerebral substance ? 

To answer this question, we will first simplify 
considerably the conditions under which conscious 
perception takes place. In fact, there is no 
perception which is not full of memories. 
With the immediate and present data of 
our senses we mingle a thousand details out of 
our past experience. In most cases these 
memories supplant our actual perceptions, of 
which we then retain only a few hints, thus 
using them merely as signs that recall to 
us former images. The convenience and the 
rapidity of perception are bought at this price ; 
but hence also springs every kind of illusion. Let 
us, for the purposes of study, substitute for this 
perception, impregnated with our past, a per 
ception that a consciousness would have if it 
were supposed to be ripe and full-grown, yet 
confined to the present and absorbed, to the 
exclusion of all else, in the task of moulding 
itself upon the external object. It may be 
urged that this is an arbitrary hypothesis, and 
that such an ideal perception, obtained by the 


elimination of individual accidents, has no corre 
spondence with reality. But we hope to show 
that the individual accidents are merely grafted 
on to this impersonal perception, which is at the 
very root of our knowledge of things ; and that 
just because philosophers have overlooked it, 
because they have not distinguished it from that 
which memory adds to or subtracts from it, they 
have taken perception as a whole for a kind of 
interior and subjective vision, which would then 
differ from memory only by its greater intensity. 
This will be our first hypothesis. But it leads 
naturally to another. However brief we suppose 
any perception to be, it always occupies a certain 
duration, and involves consequently an effort 
of memory which prolongs one into another a 
plurality of moments. As we shall endeavour 
to show, even the subjectivity of sensible quali 
ties consists above all else in a kind of contraction 
of the real, effected by our memory. In short, 
memory in these two forms, covering as it does with 
a cloak of recollections a core of immediate percep 
tion, and also contracting a number of external 
moments into a single internal moment, con 
stitutes the principal share of individual con 
sciousness in perception, the subjective side of the 
knowledge of things ; and, since we must neglect 
this share in order to make our idea clearer, we 
shall go too far along the path we have chosen. 
But we shall only have to retrace our steps 
and to correct, especially by bringing memory 


back again, whatever may be excessive in our 
conclusions. What follows, therefore, must be 
regarded as only a schematic rendering, and we 
ask that perception should be provisionally 
understood to mean not my concrete and com 
plex perception that which is enlarged by 
memories and offers always a certain breadth of 
duration but a pure perception, I mean a percep 
tion which exists in theory rather than in fact and 
would be possessed by a being placed where 
I am, living as I live, but absorbed in the 
present and capable, by giving up every form 
of memory, of obtaining a vision of matter both 
immediate and instantaneous. Adopting this 
hypothesis, let us consider how conscious per 
ception may be explained. 

To deduce consciousness would be, indeed, a bold 
undertaking ; but it is really not necessary here, be- 
cause by positing the material world we as- 
sume an a gg re g ate of images, and more- 
reflectedfrom over because it is impossible to assume 
thoiuh by a anything else . No theory of matter escapes 
mirror. ^his necessity. Reduce matter to atoms 
in motion : these atoms, though denuded of physical 
qualities, are determined only in relation to an 
eventual vision and an eventual contact, the one 
without light and the other without materiality. 
Condense atoms into centres of force, dissolve 
them into vortices revolving in a continuous fluid : 
this fluid, these movements, these centres, can 
themselves be determined only in relation to an 


impotent touch, an ineffectual impulsion, a colour 
less light ; they are still images. It is true that 
an image may be without being perceived ; it 
may be present without being represented ; and 
the distance between these two terms, presence 
and representation, seems just to measure 
the interval between matter itself and our con 
scious perception of matter. But let us examine 
the point more closely, and see in what this 
difference consists. If there were more in the 
second term than in the first, if, in order to pass from 
presence to representation, it were necessary to add 
something, the barrier would indeed be insuperable, 
and the passage from matter to perception would 
remain wrapt in impenetrable mystery. It would 
not be the same if it were possible to pass from the 
first term to the second by way of diminution, and 
if the representation of an image were less than its 
presence ; for it would then suffice that the images 
present should be compelled to abandon some 
thing of themselves in order that their mere pre 
sence should convert them into representations. 
Now, here is the image which I call a material 
object ; I have the representation of it. How 
comes it that it does not appear to be in itself 
that which it is for me ? It is because, being bound 
up with all other images, it is continued in those 
which follow it, just as it prolonged those which pre 
ceded it. To transform its existence into represen 
tation, it would be enough to suppress what follows 
it, what precedes it, and also all that fills it, and to 


retain only its external crust, its superficial skin. 
That which distinguishes it as a present image, as an 
objective reality, from a represented image is the 
necessity which obliges it to act through every one 
of its points upon all the points of all other images, 
to transmit the whole of what it receives, to oppose 
to every action an equal and contrary reaction, to 
be, in short, merely a road by which pass, in every 
direction, the modifications propagated through 
out the immensity of the universe. I should con 
vert it into representation if I could isolate it, 
especially if I could isolate its shell. Represen 
tation is there, but always virtual being neutral 
ized, at the very moment when it might become 
actual, by the obligation to continue itself and to 
lose itself in something else. To obtain this con 
version from the virtual to the actual it would be 
necessary, not to throw more light on the object, 
but on the contrary to obscure some of its aspects, 
to diminish it by the greater part of itself, so that 
the remainder, instead of being encased in its sur 
roundings as a thing, should detach itself from them 
as a picture. Now if living beings are, within the uni 
verse, just centres of indetermination, and if the 
degree of this indetermination is measured by the 
number and rank of their functions, we can con 
ceive that their mere presence is equivalent to the 
suppression of all those parts of objects in which 
their functions find no interest. They allow to 
pass through them, so to speak, those external in 
fluences which are indifferent to them ; the others 


isolated, become perceptions by their very 
isolation. Everything thus happens for us as 
though we reflected back to surfaces the light which 
emanates from them, the light which, had it passed 
on unopposed, would never have been revealed. 
The images which surround us will appear to turn 
towards our body the side, emphasized by the 
light upon it, which interests our body. They 
will detach from themselves that which we have 
arrested on its way, that which we are capable 
of influencing. Indifferent to each other because 
of the radical mechanism which binds them to 
gether, they present each to the others all their 
sides at once : which means that they act and 
react mutually by all their elements, and that none 
of them perceives or is perceived consciously. 
Suppose, on the contrary, that they encounter some 
where a certain spontaneity of reaction : their 
action is so far diminished, and this diminution of 
their action is just the representation which 
we have of them. Our representation of things 
would thus arise from the fact that they are 
thrown back and reflected by our freedom. 

When a ray of light passes from one medium 
into another, it usually traverses it with a 
change of direction. But the respective den 
sities of the two media may be such that, for a 
given angle of incidence, refraction is no longer 
possible. Then we have total reflexion. The 
luminous point gives rise to a virtual image which 
symbolizes, so to speak, the fact that the luminous 


rays cannot pursue their way. Perception is just a 
phenomenon of the same kind. That which is 
given is the totality of the images of the material 
world, with the totality of their internal elements. 
But if we suppose centres of real, that is to say 
of spontaneous, activity, the rays which reach it, 
and which interest that activity, instead of pass 
ing through those centres, will appear to be re 
flected and thus to indicate the outlines of the object 
which emits them. There is nothing positive 
here, nothing added to the image, nothing new. 
The objects merely abandon something of their 
real action in order to manifest their virtual 
action that is to say, in the main, the eventual 
influence of the living being upon them. Per 
ception therefore resembles those phenomena of 
reflexion which result from an impeded refraction ; 
it is like an effect of mirage. 

This is as much as to say that there is for images 
merely a difference of degree, and not of kind, be- 
so that tween being and being consciously per- 
tion results ceived. The reality of matter consists 
omission oi in the totality of its elements and of 

that in the , . . r , . , ~ 

totality of their actions oi every kind. Our re- 
matter which . .. , 
has no presentation of matter is the measure 

interest for . ... . , ,. . 

our needs, of our possible action upon bodies : it 
results from the discarding of what has no interest 
for our needs, or more generally for our functions. 
In one sense we might say that the perception 
of any unconscious material point whatever, in 
its instantaneousness, is infinitely greater and 


more complete than ours, since this point gathers 
and transmits the influences of all the points of the 
material universe, whereas our consciousness only 
attains to certain parts and to certain aspects of 
those parts. Consciousness, in regard to external 
perception, lies in just this choice. But there 
is, in this necessary poverty of our conscious per 
ception, something that is positive, that foretells 
spirit : it is, in the etymological sense of the word, 

The whole difficulty of the problem that occu 
pies us comes from the fact that we imagine 
perception to be a kind of photographic 
limited by view of things, taken from a fixed point 
indeterminate by that special apparatus which is called 

action the .. . . 

living being an organ of perception a photograph 
which would then be developed in the 
brain-matter by some unknown chemical and 
psychical process of elaboration. But is it not 
obvious that the photograph, if photograph there 
be, is already taken, already developed in the very 
heart of things and at all the points of space ? 
No metaphysics, no physics even, can escape this 
conclusion. Build up the universe with atoms : 
each of them is subject to the action, variable in 
quantity and quality according to the distance, 
exerted on it by all material atoms. Bring in 
Faraday s centres of force : the lines of force emitted 
in every direction from every centre bring to bear 
upon each the influences of the whole material 
world. Call up the Leibnizian monads : each is 


the mirror of the universe. All philosophers, then, 
agree on this point. Only if when we consider 
any other given place in the universe we can 
regard the action of all matter as passing 
through it without resistance and without loss, 
and the photograph of the whole as trans 
lucent : here there is wanting behind the plate 
the black screen on which the image could be 
shown. Our zones of indetermination play 
in some sort the part of the screen. They add 
nothing to what is there ; they effect merely 
this : that the real action passes through, the 
virtual action remains. 

This is no hypothesis. We content ourselves 
with formulating data with which no theory of 
perception can dispense. For no philosopher 
can begin the study of external perception with 
out assuming the possibility at least of a material 
world, that is to say, in the main, the virtual 
perception of all things. From this merely 
possible material mass he will then isolate the 
particular object which I call my body, and, in 
this body, centres of perception : he will show 
me the disturbance coming from a certain point 
in space, propagating itself along the nerves and 
reaching the centres. But here I am confronted 
by a transformation scene from fairyland. The 
material world which surrounds the body, the body 
which shelters the brain, the brain in which we 
distinguish centres, he abruptly dismisses ; and, as 
by a magician s wand, he conjures up, as a thing 


entirely new the representation of what he began 
by postulating. This representation he drives 
out of space, so that it may have nothing in 
common with the matter from which he started. 
As for matter itself, he would fain go without it, 
but cannot, because its phenomena present 
relatively to each other an order so strict and 
so indifferent as to the point of origin chosen, 
that this regularity and this indifference really 
constitute an independent existence. So that 
he must resign himself to retaining at least the 
phantasm of matter. But then he manages to 
deprive it of all the qualities which give it life. 
In an amorphous space he carves out moving 
figures ; or else (and it comes to nearly the same 
thing), he imagines relations of magnitude which 
adjust themselves one to another, mathematical 
functions which go on evolving and developing 
their own content : representation, laden with 
the spoils of matter, thenceforth displays itself 
freely in an unextended consciousness. But 
it is not enough to cut out, it is necessary to 
sew the pieces together. You must now explain 
how those qualities which you have detached 
from their material support can be joined to it 
again. Each attribute which you take away 
from matter widens the interval between repre 
sentation and its object. If you make matter 
unextended, how will it acquire extension ? If 
you reduce it to homogeneous movement, whence 
arises quality ? Above all, how are we to imagine 


a relation between a thing and its image, between 
matter and thought, since each of these terms 
possesses, by definition, only that which is lack 
ing to the other ? Thus difficulties spring up 
beneath our feet ; and every effort that you make 
to dispose of one of them does but resolve it into 
many more. What then do we ask of you ? 
Merely to give up your magician s wand, and to 
continue along the path on which you first set 
out. You showed us external images reaching 
the organs of sense, modifying the nerves, propa 
gating their influence in the brain. Well, follow 
the process to the end. The movement will pass 
through the cerebral substance (although not 
without having tarried there), and will then 
expand into voluntary action. There you have 
the whole mechanism of perception. As for 
perception itself, in so far as it is an image, you 
are not called upon to retrace its genesis, since 
you posited it to begin with, and since moreover 
no other course was open to you. In assuming 
the brain, in assuming the smallest portion of 
matter, did you not assume the totality of 
images ? What you have to explain, then, is not how 
perception arises, but how it is limited, since it 
should be the image of the whole, and is in fact 
reduced to the image of that which interests you. 
But if it differs from the mere image, precisely 
in that its parts range themselves with reference to 
a variable centre, its limitation is easy to under 
stand : unlimited dc jure, it confines itself de facto 


to indicating the degree of indetermination allowed 
to the acts of the special image which you call 
your body. And, inversely, it follows that the 
indetermination of the movements of your body, 
such as it results from the structure of the grey 
matter of the brain, gives the exact measure of the 
extent of your perception. It is no wonder, then, 
that everything happens as though your perception 
were a result of the internal motions of the brain, 
and issued in some sort from the cortical centres. 
It could not actually come from them, since the 
brain is an image like others, enveloped in the 
mass of other images, and it would be absurd 
that the container should issue from the content. 
But since the structure of the brain is like the 
detailed plan of the movements among which 
you have the choice, and since that part of the 
external images which appears to return upon 
itself in order to constitute perception includes 
precisely all the points of the universe which 
these movements could affect, conscious per 
ception and cerebral movement are in strict corre 
spondence. The reciprocal dependence of these 
two terms is therefore simply due to the fact that 
both are functions of a third, which is the indeter 
mination of the will. 

Take, for example, a luminous point P, of which 
The image, the rays impinge on the different parts 
formed and a, b, c, of the retina. At this point P 

perceived in IT > , f 

the object, science localizes vibrations of a cer 
tain, tain amplitude and duration. At the 


same point P consciousness perceives light. 
We propose to show, in the course of this 
study, that both are right ; and that there is no 
essential difference between the light and the 
movements, provided we restore to movement 
the unity, indivisibility, and qualitative hetero 
geneity denied to it by abstract mechanics ; 
provided also that we see in sensible qualities 
contractions effected by our memory. Science 
and consciousness would then coincide in the in 
stantaneous. For the moment all we need say, 
without examining too closely into the meaning 
of the words, is that the point P sends to the 
retina vibrations of light. What happens then ? 
If the visual image of the point P were not 
already given, we should indeed have to seek the 
manner in which it had been engendered, and 
should soon be confronted by an insoluble 
problem. But, whatever we do, we cannot avoid 
assuming it to begin with : the sole question 
is, then, to know how and why this image is 
chosen to form part of my perception, while an 
infinite number of other images remain ex 
cluded from it. Now I see that the vibrations 
transmitted from the point P to the various parts 
of the retina are conducted to the sub-cortical 
and cortical optic centres, often to other centres 
as well, and that these centres sometimes transmit 
them to motor mechanisms, sometimes provision 
ally arrest them. The nervous elements concerned 
are, therefore, what give efficacy to the disturbance 


received; they symbolize the indetermination of 
the will ; on their soundness this indetermination 
depends ; and consequently any injury to these 
elements, by diminishing our possible action, 
diminishes perception in the same degree. In other 
words, if there exist in the material world places 
where the vibrations received are not mechanically 
transmitted, if there are, as we said, zones of 
indetermination, these zones must occur along the 
path of what is termed the sensori-motor process ; 
and hence all must happen as though the rays 
Pa, Pb, PC were perceived along this path and 
afterwards projected into P. Further, while 
the indetermination is something which escapes 
experiment and calculation, this is not the case 
with the nervous elements by which the impres 
sion is received and transmitted. These elements 
are the special concern of the physiologist and 
the psychologist ; on them all the details of exter 
nal perception would seem to depend and by them 
they may be explained. So we may say, if we like, 
that the disturbance, after having travelled along 
these nervous elements, after having gained the 
centre, there changes into a conscious image which 
is subsequently exteriorized at the point P. But, 
when we so express ourselves, we merely bow to 
the exigencies of the scientific method ; we in 
no way describe the real process. There is not, 
in fact, an unextended image which forms itself 
in consciousness and then projects itself into P. 
The truth is that the point P, the rays which it 


emits, the retina and the nervous elements af 
fected, form a single whole ; that the luminous 
point P is a part of this whole ; and that it is 
really in P, and not elsewhere, that the image of P 
is formed and perceived. 

When we represent things to ourselves in this 
manner, we do but return to the simple convictions 
of common sense. We all of us began by believ 
ing that we grasped the very object, that we per 
ceived it in itself and not in us. When philoso 
phers disdain an idea so simple and so close to 
reality, it is because the intra-cerebral process, 
that diminutive part of perception, appears to 
them the equivalent of the whole of percep 
tion. If we suppress the object perceived and 
keep the internal process, it seems to them that 
the image of the object remains. And their belief 
is easily explained : there are many conditions, 
such as hallucination and dreams, in which images 
arise that resemble external perception in all 
their details. As, in such cases, the object has 
disappeared while the brain persists, he holds 
that the cerebral phenomenon is sufficient for 
the production of the image. But it must not 
be forgotten that in all psychical states of this 
kind memory plays the chief part. Now, we 
shall try to show later that, when perception, as 
we understand it, is once admitted, memory must 
arise, and that this memory has not, any more 
than perception itself, a cerebral state as its true 
and complete condition. But, without as yet enter- 


ing upon the examination of these two points, we 
will content ourselves with a very simple observa 
tion, which has indeed no novelty. In many 
people who are blind from birth the visual centres 
are intact ; yet they live and die without having 
formed a single visual image. Such an image, 
therefore, cannot appear unless the external object 
has, once at least, played its part : it must, once 
at any rate, have been part and parcel with repre 
sentation. Now this is what we claim and for the 
moment all that we require, for we are dealing here 
with pure perception, and not with perception 
complicated by memory . Reject then the share of 
memory, consider perception in its unmixed state, 
and you will be forced to recognize that there 
is no image without an object. But, from the 
moment that you thus posit the intra-cerebral 
processes besides the external object which causes 
them, we can clearly see how the image of that 
object is given with it and in it : how the image 
should arise from the cerebral movement we shall 
never understand. 

When a lesion of the nerves or of the centres 

interrupts the passage of the nerve vibration, 

perception is to that extent diminished. 

But an injury . 

to the brain Need we be surprised ? The office of 

diminishes , . ... - 

perception by the nervous system is to utilize that 

lessening the ., . . . . . 

appeal to vibration, to convert it into practical 

deeds, really or virtually accomplished. 

If, for one reason or another, the disturbance cannot 

pass along, it would be strange if the correspond- 


ing perception still took place, since this percep 
tion would then connect our body with points 
of space which no longer directly invite t 
to make a choice. Sever the optic nerve of an 
animal : the vibrations issuing from the luminous 
point can no longer be transmitted to the brain 
and thence to the motor nerves ; the thread, of 
which the optic nerve is a part and which binds the 
external object to the motor mechanisms of the 
animal, is broken : visual perception has there 
fore become impotent, and this very impotence 
is unconsciousness. That matter should be per 
ceived without the help of a nervous system, 
and without organs of sense, is not theoretically 
inconceivable ; but it is practically impossible, 
because such perception would be of no use. It 
would suit a phantom, not a living, and therefore 
acting, being. We are too much inclined to regard 
the living body as a world within a world, the ner 
vous system as a separate being, of which the func 
tion is, first, to elaborate perceptions, and then to 
create movements. The truth is that my nervous 
system, interposed between the objects which 
affect my body and those which I can influence, 
is a mere conductor, transmitting, sending back, 
or inhibiting movement. This conductor - is 
composed of an enormous number of threads 
which stretch from the periphery to the centre, 
and from the centre to the periphery. As many 
threads as pass from the periphery to the 
centre, so many points of space are there able 


to make an appeal to my will and to put, so 
to speak, an elementary question to my motor 
activity. Every such question is what is termed 
a perception. Thus perception is diminished by 
one of its elements each time one of the threads 
termed sensory is cut, because some part of the 
external object then becomes unable to appeal to 
activity ; and it is also diminished whenever a 
stable habit has been formed, because this time 
the ready-made response renders the question 
unnecessary. What disappears in either case is 
the apparent reflexion of the stimulus upon itself, 
the return of the light on the image whence it 
comes ; or rather that dissociation, that discern 
ment, whereby the perception is disengaged from 
the image. We may therefore say that while the 
detail of perception is moulded exactly upon that of 
the nerves termed sensory, perception as a whole 
has its true and final explanation in the tendency 
of the body to movement. 

The cause of the general illusion on this point 
lies in the apparent indifference of our movements 
to the stimulation which excites them. It seems that 
the movement of my body in order to reach and to 
modify an object is the same, whether I have been 
told of its existence by the ear or whether it has 
been revealed to me by sight or touch. My 
motor activity thus appears as a separate entity, a 
sort of reservoir whence movements issue at will, 
always the same for the same action, whatever 
the kind of image which has called it into being. 


But the truth is that the character of movements 
which are externally identical is internally differ 
ent, according as they respond to a visual, an au 
ditory or a tactile impression. Suppose I perceive 
a multitude of objects in space ; each of them, 
inasmuch as it is a visual form, solicits my acti 
vity. Now I suddenly lose my sight. No doubt I 
still have at my disposal the same quantity and 
the same quality of movements in space ; but 
these movements can no longer be co-ordinated 
to visual impressions ; they must in future follow 
tactile impressions, for example, and a new 
arrangement will take place in the brain. 
The protoplasmic expansions of the motor nervous 
elements in the cortex will be in relation, now, 
with a much smaller number of the nervous 
elements termed sensory. My activity is then 
really diminished, in the sense that although I can 
produce the same movements, the occasion comes 
more rarely from the external objects. Con 
sequently, the sudden interruption of optical 
continuity has brought with it, as its essential and 
profound effect, the suppression of a large part 
of the queries or demands addressed to my activity. 
Now such a query or demand is, as we have 
seen, a perception. Here we put our finger -on 
the mistake of those who maintain that percep 
tion springs from the sensory vibration properly 
so called, and not from a sort of question ad 
dressed to motor activity. They sever this motor 
activity from the perceptive process ; and, as 


it appears to survive the loss of perception, 
they conclude that perception is localized in the 
nervous elements termed sensory. But the truth 
is that perception is no more in the sensory 
centres than in the motor centres ; it measures 
the complexity of their relations, and is, in 
fact, where it appears to be. 

Psychologists who have studied infancy are well 

aware that our representation is at first impersonal. 

Only little by little, and as a result of 

In perception J 

fromlne 1 experience, does it adopt our body as a 
periphery centre and become our representation. 

the aggregate * 

oi images, to j^g mechanism of this process is, more- 

the centre * 

mS Sversa over > easv to understand. As my body 
moves in space, all the other images vary, 
while that image, my body, remains invariable. I 
must therefore make it a centre, to which I refer all 
the other images. My belief in an external world 
does not come, cannot come, from the fact that 
I project outside myself sensations that are unex- 
tended : how could these sensations ever acquire ex 
tension, and whence should I get the notion of ex 
teriority ? But if we allow that, as experience testi 
fies, the aggregate of images is given to begin with, 
I can see clearly how my body comes to occupy, 
within this aggregate, a privileged position. And 
I understand also whence arises the notion of in- 
teriority and exteriority, which is, to begin with, 
merely the distinction between my body and other 
bodies. For if you start from my body, as is usually 
done, you will never make me understand how 


impressions received on the surface of my body, 
impressions which concern that body alone, are able 
to become for me independent objects and form 
an external world. But if, on the contrary, all 
images are posited at the outset, my body will 
necessarily end by standing out in the midst of 
them as a distinct thing, since they change unceas 
ingly, and it does not vary. The distinction between 
the inside and the outside will then be only a dis 
tinction between the part and the whole. There is, 
first of all, the aggregate of images ; and then, in 
this aggregate, there are centres of action, from 
which the interesting images appear to be reflected : 
thus perceptions are born and actions made ready. 
My body is that which stands out as the centre of 
these perceptions ; my personality is the being to 
which these actions must be referred. The whole 
subject becomes clear if we travel thus from the peri 
phery to the centre, as the child does, and as we 
ourselves are invited to do by immediate experience 
and by common sense . On the contrary everything 
becomes obscure, and problems are multiplied on 
all sides, if we attempt, with the theorists, to travel 
from the centre to the periphery. Whence arises, 
then, this idea of an external world constructed arti 
ficially, piece by piece, out of unextended sensa 
tions, though we can neither understand how 
they come to form an extended surface, nor how 
they are subsequently projected outside our body ? 
Why insist, in spite of appearances, that I should 
go from my conscious self to my body, then 


from my body to other bodies, whereas in fact I 
place myself at once in the material world in 
general, and then gradually cut out within 
it the centre of action which I shall come 
to call my body and to distinguish from all 
others ? There are so many illusions gathered 
round this belief in the originally unex- 
tended character of our external perception ; there 
are, in the idea that we project outside our 
selves states which are purely internal, so many 
misconceptions, so many lame answers to badly 
stated questions, that we cannot hope to throw 
light on the whole subject at once. We believe 
that light will increase, as we show more clearly, 
behind these illusions, the metaphysical error which 
confounds the unbroken extensity with homo 
geneous space, and the psychological error which 
confounds pure perception with memory. But 
these illusions are, nevertheless, connected with real 
facts, which we may here indicate in order to 
correct their interpretation. 

The first of these facts is that our senses require 
education. Neither sight nor touch is able at 
objection the outset to localize impressions. A 
SKo-cSS ser i es f comparisons and inductions is 
of d the a senses necessary, whereby we gradually co- 
i^?o! al s h an " ordinate one impression with another, 
education. Hence philosophers may jump to the 
belief that sensations are in their essence inexten- 
sive, and that they constitute extensity by their 
juxtaposition. But is it not clear that, upon the 


hypothesis just advanced, our senses are equally in 
need of education, not of course in order to accom 
modate themselves to things, but to accommodate 
themselves to each other ? Here, in the midst of all 
the images, there is a certain image which I term 
my body, and of which the virtual action reveals 
itself by an apparent reflexion of the surround 
ing images upon themselves. Suppose there are 
so many kinds of possible action for my body: 
there must be an equal number of systems of 
reflexion for other bodies ; and each of these 
systems will be just what is perceived by one of 
my senses. My body, then, acts like an image 
which reflects others, and which, in so doing, 
analyses them along lines corresponding to the 
different actions which it can exercise upon them. 
And, consequently, each of the qualities perceived 
in the same object by my different senses symbolizes 
a particular direction of my activity, a par 
ticular need. Now, will all these perceptions of 
a body by my different senses give me, when 
united, the complete image of that body ? Cer 
tainly not, because they have been gathered from 
a larger whole. To perceive all the influences 
from all the points of all bodies would be to de 
scend to the condition of a material object. Con 
scious perception signifies choice, and consciousness 
mainly consists in this practical discernment. The 
diverse perceptions of the same object, given by 
my different senses, will not, then, when put to 
gether, reconstruct the complete image of the 


object ; they will remain separated from each other 
by intervals which measure, so to speak, the gaps 
in my needs. It is to fill these intervals that an 
education of the senses is necessary. The aim of 
this education is to harmonize my senses with 
each other, to restore between their data a 
continuity which has been broken by the discon 
tinuity of the needs of my body, in short to re 
construct, as nearly as may be, the whole of the 
material object. This, on our hypothesis, ex 
plains the need for an education of the senses. 
Now let us compare it with the preceding explana 
tion. In the first, unextended sensations of sight 
combine with unextended sensations of touch and 
of the other senses, to give, by their synthesis, 
the idea of a material object. But, to begin with, 
it is not easy to see how these sensations can ac 
quire extension, nor how, above all, when exten 
sion in general has been acquired, we can explain 
in particular the preference of a given one of these 
sensations for a given point of space. And then 
we may ask by what happy agreement, in virtue 
of what pre-established harmony, do these sen 
sations of different kinds co-ordinate themselves 
to form a stable object, henceforth solidified, 
common to my experience and to that of all men, 
subject, in its relation to other objects, to those 
inflexible rules which we call the laws of nature ? 
In the second, the data of our different senses 
are, on the contrary, the very qualities of things, 
perceived first in the things rather than in us : 


is it surprising that they come together, since 
abstraction alone has separated them ? On the 
first hypothesis, the material object is nothing of 
ah 1 that we perceive : you put on one side the con 
scious principle with the sensible qualities, and 
on the other a matter of which you can predicate 
nothing, which you define by negations because 
you have begun by despoiling it of all that reveals 
it to us. In the second, an ever-deepening know 
ledge of matter becomes possible. Far from 
depriving matter of anything perceived, we must 
on the contrary bring together all sensible quali 
ties, restore their relationship, and re-establish 
among them the continuity broken by our needs. 
Our perception of matter is, then, no longer 
either relative or subjective, at least in principle, 
and apart, as we shall see presently, from 
affection and especially from memory ; it is 
merely dissevered by the multiplicity of our 
needs. On the first hypothesis, spirit is as un 
knowable as matter, for you attribute to it the 
undefinable power of evoking sensations we know 
not whence, and of projecting them, we know 
not why, into a space where they will form bodies. 
On the second, the part played by consciousness 
is clearly defined : consciousness means virtual 
action ; and the forms acquired by mind, those 
which hide the essence of spirit from us, should, 
with the help of this second principle, be removed 
as so many concealing veils. Thus, on our hypo 
thesis, we begin to see the possibility of a clearer 


distinction between spirit and matter, and of a 
reconciliation between them. But we will leave 
this first point and come to the second. 

The second fact brought forward consists in 

what was long termed the specific energy of the 

nerves. We know that stimulation of 


drawn from the optic nerve by an external shock or 

the so-called 

specific by an electnc current will produce a 

energy, of the * * 

nerves. visual sensation, and that this same 
electric current applied to the acoustic or 
to the glosso-pharyngeal nerve will cause a sound 
to be heard or a taste to be perceived. From 
these very particular facts have been deduced two 
very general laws : that different causes acting on 
the same nerve excite the same sensation; and 
that the same cause, acting on different nerves, 
provokes different sensations. And from these 
laws it has been inferred that our sensations are 
merely signals, and that the office of each sense is to 
translate into its own language homogeneous and 
mechanical movements occurring in space. Hence, 
as a conclusion, the idea of cutting our perception 
into two distinct parts, thenceforward incapable 
of uniting : on the one hand homogeneous move 
ments in space, and on the other unextended sen 
sations in consciousness. Now, it is not our part 
to enter into an examination of the physiological 
problems raised by the interpretation of the two 
laws : in whatever way these laws are understood, 
whether the specific energy is attributed to the 
nerves or whether it is referred to the centres, insur- 



mountable difficulties arise. But the very existence 
of the laws themselves appears more and more 
problematical. Lotze himself already suspected 
a fallacy in them. He awaited, before putting 
faith in them, sound waves which should give to 
the eye the sensation of light, or luminous vibra 
tions which should give to the ear a sound/ l 
The truth is that all the facts alleged can be brought 
back to a single type : the one stimulus capable 
of producing different sensations, the multiple 
stimuli capable of inducing the same sensation, 
are either an electric current or a mechanical 
cause capable of determining in the organ a modi 
fication of electrical equilibrium. Now we may 
well ask whether the electrical stimulus does not 
include different components, answering objec 
tively to sensations of different kinds, and whether 
the office of each sense is not merely to extract 
from the whole the component that concerns it. 
We should then have, indeed, the same stimuli 
giving the same sensations, and different stimuli 
provoking different sensations. To speak more 
precisely, it is difficult to admit, for instance, that 
applying an electrical stimulus to the tongue 
would not occasion chemical changes ; and these 
changes are what, in all cases, we term tastes. 
On the other hand, while the physicist has been 
able to identify light with an electro-magnetic 
disturbance, we may say, inversely, that what he 

1 Lotze, Metaphysic, Oxford, 1887, vol. ii, p. 206. 


calls here an electro-magnetic disturbance is light, 
so that it is really light that the optic nerve per 
ceives objectively when subject to electrical 
stimulus. The doctrine of specific energy appears 
to be nowhere more firmly based than in the case 
of the ear : nowhere also has the real existence of 
the thing perceived become more probable. We 
will not insist on these facts, because they will 
be found stated and exhaustively discussed in a 
recent work. 1 We will only remark that the 
sensations here spoken of are not images per 
ceived by us outside our body, but rather affec 
tions localized within the body. Now it results from 
the nature and use of our body, as we shall see, 
that each of its so-called sensory elements has 
its own real action, which must be of the same 
kind as its virtual action on the external objects 
which it usually perceives ; and thus we can 
understand how it is that each of the sensory 
nerves appears to vibrate according to a fixed 
manner of sensation. But to elucidate this point 
we must consider the nature of affection. Thus 
we are led to the third and last argument which 
we have to examine. 

This third argument is drawn from the fact 
that we pass by insensible degrees from the repre 
sentative state which occupies space, to the 
affective state which appears to be unextended. 

1 Schwarz, Das Wahrnehmungsproblem, Leipzig, 1892, pp- 
313 and seq. 


Hence it is inferred that all sensation is 
naturally and necessarily unextended, 

Objections .-, , 

drawn from so that extensity is superimposed upon 

the so-called , 1^1 r 

subjectivity sensation, and the process of percep- 

of affective ,- , ,. f 

states. tion consists in an extenonzation of 

internal states. The psychologist starts, 
whwett is in f act, from his body, and, as the im 

pressions received at the periphery of 
this body seem to him sufficient for the recon- 
stitution of the entire material universe, to 
his body he at first reduces the universe. But 
this first position is not tenable ; his body 
has not, and cannot have, any more or any 
less reality than all other bodies. So he must 
go farther, follow to the end the consequences 
of his principle, and, after having narrowed the 
universe to the surface of the living body, 
contract this body itself into a centre which he 
will end by supposing unextended. Then, from 
this centre will start unextended sensations, which 
will swell, so to speak, will grow into extensity, 
and will end by giving extension first to his 
body, and afterwards to all other material objects. 
But this strange supposition would be impos 
sible if there were not, in point of fact, between 
images and ideas, the former extended and -the 
latter unextended, a series of intermediate states, 
more or less vaguely localized, which are the 
affective states. Our understanding, yielding to 
its customary illusion, poses the dilemma, that 
a thing either is or is not extended ; and as the 


affective state participates vaguely in extension, 
is in fact imperfectly localized, we conclude that 
this state is absolutely unextended. But then the 
successive degrees of extension, and extensity itself, 
will have to be explained by I know not what ac 
quired property of unextended states ; the history 
of perception will become that of internal unex 
tended states which acquire extension and project 
themselves without. Shall we put the argument 
in another form ? There is hardly any percep 
tion which may not, by the increase of the action 
of its object upon our body, become an affection, 
and, more particularly, pain. Thus we pass in 
sensibly from the contact with a pin to its prick. 
Inversely the decreasing pain coincides with the 
lessening perception of its cause, and exteriorizes 
itself, so to speak, into a representation. So it does 
seem, then, as if there were a difference of degree 
and not of nature between affection and perception. 
Now, the first is intimately bound up with my per 
sonal existence : what, indeed, would be a pain 
detached from the subject that feels it ? It seems 
therefore that it must be so with the second, and 
that external perception is formed by projecting 
into space an affection which has become harm 
less. Realists and idealists are agreed in this 
method of reasoning. The latter see in the 
material universe nothing but a synthesis of sub 
jective and unextended states ; the former add 
that, behind this synthesis, there is an indepen 
dent reality corresponding to it ; but both con- 


elude, from the gradual passage of affection to 
representation, that our representation of the 
material universe is relative and subjective, and 
that it has, so to speak, emerged from us, rather 
than that we have emerged from it. 

Before criticizing this questionable interpretation 
of an unquestionable fact, we may show that it does 
not succeed in explaining, or even in throwing light 
upon, the nature either of pain or of perception. 
That affective states, essentially bound up with 
my personality, and vanishing if I disappear, 
should acquire extensity by losing intensity, 
should adopt a definite position in space, and 
build up a firm, solid experience, always in accord 
with itself and with the experience of other 
men this is very difficult to realize. Whatever 
we do, we shall be forced to give back to sen 
sations, in one form or another, first the exten 
sion and then the independence which we have 
tried to do without. But, what is more, affection, 
on this hypothesis, is hardly clearer than repre 
sentation. For if it is not easy to see how affec 
tions, by diminishing in intensity, become 
representations, neither can we understand how 
the same phenomenon, which was given at first 
as perception, becomes affection by an increase 
of intensity. There is in pain something positive 
and active, which is ill explained by saying, as 
do some philosophers, that it consists in a con 
fused representation. But still this is not the 
principal difficulty. That the gradual augmen- 


tation of the stimulus ends by transforming per 
ception into pain, no one will deny ; it is none 
the less true that this change arises at a definite 
moment : why at this moment rather than at 
another ? and what special reason brings about 
that a phenomenon of which I was at first only an 
indifferent spectator suddenly acquires for me a 
vital interest ? Therefore, on this hypothesis 
I fail to see either why, at a given moment, a dim 
inution of intensity in the phenomenon confers 
on it a right to extension and to an apparent 
independence; or why an increase of intensity 
should create, at one moment rather than at 
another, this new property, the source of positive 
action, which is called pain. 

Let us return now to our hypothesis, and show 
that affection must, at a given moment, arise out 
Real of the image. We shall thus under- 

o?pataTtt fl is stand how it is that we pass from a 
Unavailing perception which has extensity to an 
affection which is believed to be unex- 
tended. But some preliminary remarks on the 
real significance of pain are indispensable. 

When a foreign body touches one of the pro 
longations of the amoeba, that prolongation is 
retracted; every part of the protoplasmic mass 
is equally able to receive a stimulation and to 
react against it ; perception and movement being 
here blended in a single property, contrac 
tility. But, as the organism grows more com 
plex, there is a division of labour ; functions 


become differentiated, and the anatomical ele 
ments thus determined forego their independence. 
In such an organism as our own, the nerve fibres 
termed sensory are exclusively empowered to 
transmit stimulation to a central region whence the 
vibration will be passed on to motor elements. 
It would seem then that they have abandoned 
individual action to take their share, as outposts, 
in the manoeuvres of the whole body. But none 
the less they remain exposed, singly, to the same 
causes of destruction which threaten the organ 
ism as a whole ; and while this organism is able to 
move, and thereby to escape a danger or to repair 
a loss, the sensitive element retains the relative 
immobility to which the division of labour con 
demns it. Thence arises pain, which, in our view, 
is nothing but the effort of the damaged element 
to set things right, a kind of motor tendency in 
a sensory nerve. Every pain, then, must consist 
in an effort, an effort which is doomed to be 
unavailing. Every pain is a local effort, and in 
its very isolation lies the cause of its impotence ; 
because the organism, by reason of the solidarity 
of its parts, is able to move only as a whole. 
It is also because the effort is local that pain is 
entirely disproportioned to the danger incurred 
by the living being. The danger may be mortal 
and the pain slight ; the pain may be unbearable 
(as in toothache) and the danger insignificant. 
There is then, there must be, a precise moment 
when pain intervenes : it is when the interested 


part of the organism, instead of accepting the 
stimulation, repels it. And it is not merely a dif 
ference of degree that separates perception from 
affection, but a difference in kind. 

Now, we have considered the living body as a 
kind of centre whence is reflected on the surround 
ing objects the action which these objects exercise 
upon it : in that reflexion external perception 
consists. But this centre is not a mathematical 
point ; it is a body, exposed, like all natural bodies, 
to the action of external causes which threaten 
to disintegrate it. We have just seen that it 
resists the influence of these causes. It does not 
merely reflect action received from without ; it 
struggles, and thus absorbs some part of this action. 
Here is the source of affection. We might there 
fore say, metaphorically, that while perception 
measures the reflecting power of the body, affection 
measures its power to absorb. 

But this is only a metaphor. We must con 
sider the matter more carefully, in order to under- 
stand clearly that the necessity of affec- 
t ^ on follows from the very existence of 
perception. Perception, understood as 
virtual action. we understand it, measures our possible 
action upon things, and thereby, inversely, the 
possible action of things upon us. The greater 
the body s power of action (symbolized by a higher 
degree of complexity in the nervous system), the 
wider is the field that perception embraces. The 
distance which separates our body from an object 


perceived really measures, therefore, the greater or 
less imminence of a danger, the nearer or more 
remote fulfilment of a promise. And, conse 
quently, our perception of an object distinct from 
our body, separated from our body by an interval, 
never expresses anything but a virtual action. 
But the more the distance decreases between this 
object and our body (the more, in other words, 
the danger becomes urgent or the promise immedi 
ate), the more does virtual action tend to pass into 
real action. Suppose the distance reduced to zero, 
that is to say that the object to be perceived 
coincides with our body, that is to say again, 
that our body is the object to be perceived. Then 
it is no longer virtual action, but real action, that 
this specialized perception will express : and this is 
exactly what affection is. Our sensations are, then, 
to our perceptions that which the real action of our 
body is to its possible or virtual action. Its virtual 
action concerns other objects, and is manifested 
within those objects ; its real action concerns 
itself, and is manifested within its own sub 
stance. Everything then will happen as if, by 
a true return of real and virtual actions to their 
points of application or of origin, the external 
images were reflected by our body into surrounding 
space, and the real actions arrested by it within 
itself. And that is why its surface, the common 
limit of the external and the internal, is the only 
portion of space which is both perceived and 


That is to say, once more, that my perception is 
outside my body, and my affection within it. 
Just as external objects are perceived by me 
where they are, in themselves and not in me, 
so my affective states are experienced there where 
they occur, that is, at a given point in my body. 
Consider the system of images which is called the 
material world. My body is one of them. 
Around this image is grouped the representation, 
i.e. its eventual influence on the others. Within 
it occurs affection, i.e. its actual effort upon 
itself. Such is indeed the fundamental differ 
ence which every one of us naturally makes 
between an image and a sensation. When we say 
that the image exists outside us, we signify by 
this that it is external to our body. When we 
speak of sensation as an internal state, we mean 
that it arises within in our body. And this is 
why we affirm that the totality of perceived images 
subsists, even if our body disappears, whereas 
we know that we cannot annihilate our body with 
out destroying our sensations. 

Hence we begin to see that we must correct, at 
least in this particular, our theory of pure percep 
tion. We have argued as though our 

That is to 

say pure perception were a part of the images, 

perception ; i_ r . i_ , 

exists only in detached, as such, from their entirety : as 

theory ; in . . . . . 

fact it is though, expressing the virtual action of 

always mixed , " . , , , 

with aflec- the object upon our body, or of our body 
upon the object, perception merely iso 
lated from the total object that aspect of it which 


interests us. But we have to take into account the 
fact that our body is not a mathematical point in 
space, that its virtual actions are complicated by 
and impregnated with real actions, or, in other 
words, that there is no perception without affection. 
Affection is, then, that part or aspect of the inside of 
our body which we mix with the image of external 
bodies ; it is what we must first of all subtract from 
perception to get the image in its purity. But the 
psychologist who shuts his eyes to the difference 
of function and nature between perception and 
sensation, the latter involving a real action, 
and the former a merely possible action, can 
only find between them a difference of degree. 
Because sensation (on account of the confused 
effort which it involves) is only vaguely loca 
lized, he declares it unextended, and thence makes 
sensation in general the simple element from which 
we obtain by composition all external images. The 
truth is that affection is not the primary matter 
of which perception is made ; it is rather the 
impurity with which perception is alloyed. 

Here we grasp, at its origin, the error which 
leads the psychologist to consider sensation as 
unextended and perception as an aggregate of 
sensations. This error is reinforced, as we shall 
see, by illusions derived from a false conception of 
the role of space and of the nature of extensity. 
But it has also the support of misinterpreted facts, 
which we must now examine. 

It appears, in the first place, as if the localiza- 


tion of an affective sensation in one part of the 
why aflec- body were a matter of gradual training. 
tobe iS eSfy * A certain time elapses before the child 
unextended. can touch with the finger the precise 
point where it has been pricked. The fact is 
indisputable ; but all that can be concluded from 
it is that some tentative essays are required to 
co-ordinate the painful impressions on the skin, 
which has received the prick, with the impressions 
of the muscular sense which guides the movement 
of arm and hand. Our internal affections, like 
our external perceptions, are of different kinds. 
These kinds, like those of perception, are discon 
tinuous, separated by intervals which are filled up 
in the course of education. But it does not at all 
follow that there is not, for each affection, an 
immediate localization of a certain kind, a local 
colour which is proper to it. We may go further : 
if the affection has not this local colour at once, it 
will never have it. For all that education can do 
is to associate with the actual affective sensation 
the idea of a certain potential perception of sight 
and touch, so that a definite affection may evoke 
the image of a visual or tactile impression, equally 
definite. There must be, therefore, in this affec 
tion itself, something which distinguishes it from 
other affections of the same kind, and permits of 
its reference to this or that potential datum of sight 
or touch rather than to any other. But is not this 
equivalent to saying that affection possesses, from 
the outset, a certain determination of extensity ? 


Again, it is alleged that there are erroneous 
localizations ; for example, the illusion of those 
who have lost a limb (an illusion which requires, 
however, further examination) . But what can we 
conclude from this beyond the fact that education, 
once acquired, persists, and that such data of 
memory as are more useful in practical life supplant 
those of immediate consciousness ? It is indispen 
sable, in view of action, that we should translate 
our affective experience into eventual data of sight, 
touch, and muscular sense. When once this 
translation is made, the original pales ; but it 
never could have been made if the original had not 
been there to begin with, and if sensation had 
not been, from the beginning, localized by its own 
power and in its own way. 

But the psychologist has much difficulty in 
accepting this idea from common sense. Just 
if we make as perception, in his view, could be in 
e?t e ra-s ?atiai tne things perceived only if they had 
perception perception, so a sensation cannot be in 
inexplicable, ^g nerve unless the nerve feels. Now 
it is evident that the nerve does not feel. So 
he takes sensation away from the point where 
common sense localizes it, carries it towards the 
brain, on which, more than on the nerve, it appears 
to depend, and logically should end by placing 
it in the brain. But it soon becomes clear that 
if it is not at the point where it appears to arise, 
neither can it be anywhere else : if it is not in the 
nerve, neither is it in the brain ; for to explain its 


projection from the centre to the periphery a 
certain force is necessary, which must be attributed 
to a consciousness that is to some extent active. 
Therefore, he must go further ; and, after having 
made sensations converge towards the cerebral 
centre, must push them out of the brain, and 
thereby out of space. So he has to imagine on 
the one hand sensations that are absolutely 
unextended, and on the other hand an empty space 
indifferent to the sensations which are projected 
into it : henceforth he will exhaust himself in 
efforts of every kind to make us understand how 
unextended sensations acquire extensity, and why 
they choose for their abode this or that point of 
space rather than any other. But this doctrine 
is not only incapable of showing us clearly how 
the unextended takes on extension ; it renders 
affection, extension, and representation equally 
inexplicable. It must assume affective states as 
so many absolutes, of which it is impossible to 
say why they appear in or disappear from con 
sciousness at definite moments. The passage from 
affection to representation remains wrapt in an 
equally impenetrable mystery, because, once again, 
you will never find in internal states, which are 
supposed to be simple and unextended, any reason 
why they should prefer this or that particular 
order in space. And, finally, representation itself 
must be posited as an absolute : we cannot guess 
either its origin or its goal. 

Everything becomes clearer, on the other hand, 


if we start from representation itself, that is to say 
from the totality of perceived images. My percep 
tion, in its pure state, isolated from memory, does 
not go on from my body to other bodies ; it is, to 
begin with, in the aggregate of bodies, then gradu 
ally limits itself and adopts my body as a centre. 
And it is led to do so precisely by experience of the 
double faculty, which this body possesses, of per 
forming actions and feeling affections ; in a word, by 
experience of the sensori-motor power of a certain 
image, privileged among other images. For, on 
the one hand, this image always occupies the centre 
of representation, so that the other images range 
themselves round it in the very order in which they 
might be subject to its action ; on the other hand, 
I know it from within, by sensations which I term 
affective, instead of knowing only, as in the case of 
the other images, its outer skin. There is then, in 
the aggregate of images, a privileged image, 
perceived in its depths and no longer only on the 
surface the seat of affection and, at the same 
time, the source of action : it is this particular 
image which I adopt as the centre of my universe 
and as the physical basis of my personality. 

But before we go on to establish the precise rela 
tion between the personality and the images in 
which it dwells, let us briefly sum up, contrast 
ing it with the analyses of current psychology, the 
theory of pure perception which we have just 
sketched out. 

We will return, for the sake of simplicity, to 


the sense of sight, which we chose as our example. 
Psychology has accustomed us to assume 

The result of J &J 

positing sensa- the elementary sensations corresponding 

tions and J 

then con- to the impressions received by the rods 


perception and cones of the retina. With these 

with them. 

sensations it goes on to reconstitute 
visual perception. But, in the first place, there is 
not one retina, there are two ; so that we have to 
explain how two sensations, held to be distinct, 
combine to form a single perception correspond 
ing to what we call a point in space. 

Suppose this problem solved. The sensations 
in question are unextended ; how will they ac 
quire extension ? Whether we see in extensity 
a framework ready to receive sensations, or an 
effect of the mere simultaneity of sensations co 
existing in consciousness without coalescing, in 
either case something new is introduced with 
extensity, something unaccounted for ; the 
process by which sensation arrives at extension, 
and the choice by each elementary sensation of a 
definite point in space, remain alike unexplained, 

We will leave this difficulty, and suppose visual 
extension constituted. How does it in its turn re 
unite with tactile extension ? All that my vision 
perceives in space is verified by my touch. Shall 
we say that objects are constituted by just the 
co-operation of sight and touch, and that the agree 
ment of the two senses in perception may be 
explained by the fact that the object perceived is 
their common product ? But how could there be 


anything common, in the matter of quality, between 
an elementary visual sensation and a tactile sensa 
tion, since they belong to two different genera ? The 
correspondence between visual and tactile extension 
can only be explained, therefore, by the parallelism 
of the order of the visual sensations with the order 
of the tactile sensations. So we are now obliged 
to suppose, over and above visual sensations, over 
and above tactile sensations, a certain order which 
is common to both, and which consequently must 
be independent of either. We may go further : this 
order is independent of our individual perception, 
since it is the same for all men, and constitutes 
a material world in which effects are linked with 
causes, in which phenomena obey laws. We are 
thus led at last to the hypothesis of an objective 
order, independent of ourselves ; that is to say, of 
a material world distinct from sensation. 

We have had, as we advanced, to multiply our 
irreducible data, and to complicate more and more 
the simple hypothesis from which we started. But 
have we gained anything by it ? Though the 
matter which we have been led to posit is indis 
pensable in order to account for the marvellous 
accord of sensations among themselves, we still 
know nothing of it, since we must refuse all 
the qualities perceived, all the sensations of which 
it has only to explain the correspondence. It is 
not, then, it cannot be, anything of what we 
know, anything of what we imagine. It remains 
a mysterious entity. 


But our own nature, the office and the function 
of our personality, remain enveloped in equal 
mystery. For these elementary unextended sen 
sations which develop themselves in space, whence 
do they come, how are they born, what purpose 
do they serve ? We must posit them as so many 
absolutes, of which we see neither the origin nor 
the end. And even supposing that we must 
distinguish, in each of us, between the spirit 
and the body, we can know nothing either of 
body or of spirit, nor of the relation between them. 

Now in what does this hypothesis of ours consist, 
and at what precise point does it part company 
Action, not with, the other ? Instead of starting from 
JnoSdbSthe affection, of which we can say nothing, 
starting point. s i nce there is no reason why it should be 
what it is rather than anything else, we start from 
action, that is to say from our faculty of effecting 
changes in things, a faculty attested by consciousness 
and towards which all the powers of the organized 
body are seen to converge. So we place ourselves 
at once in the midst of extended images ; and in 
this material universe we perceive centres of inde- 
termination, characteristic of life. In order that 
actions may radiate from these centres, the move 
ments or influences of the other images must be on 
the one hand received and on the other utilized. 
Living matter, in its simplest form, and in a 
homogeneous state, accomplishes this function 
simultaneously with those of nourishment and 
repair. The progress of such matter consists in 


sharing this double labour between two categories 
of organs, the purpose of the first, called organs 
of nutrition, being to maintain the second : these 
last are made for action ; they have as their 
simple type a chain of nervous elements, connect 
ing two extremities of which the one receives 
external impressions and the other executes move 
ments. Thus, to return to the example of visual 
perception, the office of the rods and cones is merely 
to receive excitations which will be subsequently 
elaborated into movements, either accomplished 
or nascent. No perception can result from this, 
and nowhere, in the nervous system, are there 
conscious centres ; but perception arises from the 
same cause which has brought into being the chain 
of nervous elements, with the organs which sustain 
them and with life in general. It expresses and 
measures the power of action in the living being, 
the indetermination of the movement or of the 
action which will follow the receipt of the stimulus. 
This indetermination, as we have shown, will ex 
press itself in a reflexion upon themselves, or 
better in a division, of the images which surround 
our body ; and, as the chain of nervous elements 
which receives, arrests, and transmits movements 
is the seat of this indetermination and gives its 
measure, our perception will follow all the detail 
and will appear to express all the variations of 
the nervous elements themselves. Perception, 
in its pure state, is then, in very truth, a part of 
things. And as for affective sensation, it does 


not spring spontaneously from the depths of 
consciousness to extend itself, as it grows weaker, 
in space; it is one with the necessary modifi 
cations to which, in the midst of the surround 
ing images that influence it, the particular 
image that each one of us terms his body is 
subj ect. 

Such is our simplified, schematic theory of exter 
nal perception. It is the theory of pure percep 
tion. If we went no further, the part of con 
sciousness in perception would thus be confined to 
threading on the continuous string of memory 
an uninterrupted series of instantaneous visions, 
which would be a part of things rather than of 
ourselves. That this is the chief office of con 
sciousness in external perception is indeed 
what we may deduce a priori from the very defini 
tion of living bodies. For though the function 
of these bodies is to receive stimulations in order 
to elaborate them into unforeseen reactions, still 
the choice of the reaction cannot be the work of 
chance. This choice is likely to be inspired by 
past experience, and the reaction does not take 
place without an appeal to the memories which 
analogous situations may have left behind them. 
The indetermination of acts to be accomplished 
requires then, if it is not to be confounded with 
pure caprice, the preservation of the images per 
ceived. It may be said that we have no grasp of 
the future without an equal and corresponding 


outlook over the past, that the onrush of our 
activity makes a void behind it into which memories 
flow, and that memory is thus the reverbera 
tion, in the sphere of consciousness, of the inde- 
termination of our will. But the action of memory 
goes further and deeper than this superficial 
glance would suggest. The moment has come 
to reinstate memory in perception, to correct 
in this way the element of exaggeration in our 
conclusions, and so to determine with more 
precision the point of contact between con 
sciousness and things, between the body and 
the spirit. 

We assert, at the outset, that if there be memory, 

that is, the survival of past images, these images 

must constantly mingle with our percep- 

Perception is . r . 

less objective tion of the present, and may even take its 

in fact than in _.-. . -, . . 

theory because place. For if they have survived it is with 

it includes . 

a share oi a view to utility : at every moment they 

memory. . . 

complete our present experience, enrich 
ing it with experience already acquired ; and, as the 
latter is ever increasing, it must end by covering up 
and submerging the former. It is indisputable that 
the basis of real, and so to speak instantaneous, 
intuition, on which our perception of the external 
world is developed, is a small matter compared 
with all that memory adds to it. Just because 
the recollection of earlier analogous intuitions 
is more useful than the intuition itself, being 
bound up in memory with the whole series of 
subsequent events, and capable thereby of throw- 


ing a better light on our decision, it supplants the 
real intuition of which the office is then merely 
we shall prove it later to call up the recollection, 
to give it a body, to render it active and thereby 
actual. We had every right, then, to say that 
the coincidence of perception with the object 
perceived exists in theory rather than in fact. 
We must take into account that perception ends 
by being merely an occasion for remembering, 
that we measure in practice the degree of reality 
by the degree of utility, and, finally, that it 
is our interest to regard as mere signs of the 
real those immediate intuitions which are, in 
fact, part and parcel with reality. But here we 
discover the mistake of those who say that to 
perceive is to project externally unextended 
sensations which have been drawn from our 
own depths, and then to develop them in space. 
They have no difficulty in showing that our com 
plete perception is filled with images which belong 
to us personally, with exteriorized (that is to say 
recollected) images ; but they forget that an 
impersonal basis remains in which perception 
coincides with the object perceived; and which 
is, in fact, externality itself. 

The capital error, the error which, passing over 

from psychology into metaphysic, shuts us out 

in the end from the knowledge both of 

Pure peroep- M. AI_ T_- u 

tion and pure body and of spirit, is that which sees 

constantly only a difference of intensity, instead 

of a difference of nature, between pure 


perception and memory. Our perceptions are un 
doubtedly interlaced with memories, and inversely, 
a memory, as we shall show later, only becomes 
actual by borrowing the body of some perception 
into which it slips. These two acts, perception 
and recollection, always interpenetrate each other, 
are always exchanging something of their sub 
stance as by a process of endosmosis. The proper 
office of psychologists would be to dissociate 
them, to give back to each its natural purity ; 
in this way many difficulties raised by psychology, 
and perhaps also by metaphysics, might be les 
sened. But they will have it that these mixed 
states, compounded, in unequal proportions, of 
pure perception and pure memory, are simple. 
And so we are condemned to an ignorance 
alike of pure memory and of pure perception; 
to knowing only a single kind of phenomenon 
which will be called now memory and now per 
ception, according to the predominance in it of 
one or other of the two aspects ; and, con 
sequently, to finding between perception and 
memory only a difference in degree and not in 
kind. The first effect of this error, as we shall 
see in detail, is to vitiate profoundly the theory 
of memory ; for if we make recollection 
merely a weakened perception we misunderstand 
the essential difference between the past and the 
present, we abandon all hope of understanding 
the phenomena of recognition, and, more gener 
ally, the mechanism of the unconscious. But, in- 


versely, if recollection is regarded as a weakened 
perception, perception must be regarded as a 
stronger recollection. We are driven to argue as 
though it was given to us after the manner of a 
memory, as an internal state, a mere modification 
of our personality ; and our eyes are closed to the 
primordial and fundamental act of perception, 
the act, constituting pure perception, whereby we 
place ourselves in the very heart of things. And 
thus the same error, which manifests itself in 
psychology by a radical incapacity to explain the 
mechanism of memory, will in metaphysics pro 
foundly influence the idealistic and realistic 
conceptions of matter. 

For realism, in fact, the invariable order of the 
phenomena of nature lies in a cause distinct from 
our perceptions, whether this cause must remain 
unknowable, or whether we can reach it by an 
effort (always more or less arbitrary) of meta 
physical construction. For the idealist, on the 
contrary, these perceptions are the whole of 
reality, and the invariable order of the phenomena 
of nature is but the symbol whereby we express, 
alongside of real perceptions, perceptions that are 
possible. But, for realism as for idealism, percep 
tions are veridical hallucinations/ states of the 
subject, projected outside himself ; and the two 
doctrines differ merely in this : that in the one 
these states constitute reality, in the other they 
are sent forth to unite with it. 

But behind this illusion lurks yet another that 


extends to the theory of knowledge in general. We 
have said that the material world is made 
philosophy up of objects, or, if you prefer it, of 
dissociate images, of which all the parts act and 
react upon each other by movements. And 
that which constitutes our pure perception 
is our dawning action, in so far as it is pre 
figured in those images. The actuality of 
our perception thus lies in its activity, in the 
movements which prolong it, and not in its 
greater intensity: the past is only idea, the 
present is ideo-motor. But this is what our 
opponents are determined not to see, because 
they regard perception as a kind of contempla 
tion, attribute to it always a purely speculative 
end, and maintain that it seeks some strange 
disinterested knowledge ; as though, by isolating 
it from action, and thus severing its links with the 
real, they were not rendering it both inexplicable 
and useless. But thenceforward all difference 
between perception and recollection is abolished, 
since the past is essentially that which acts no longer, 
and since, by misunderstanding this characteristic 
of the past, they become incapable of making a 
real distinction between it and the present, i.e. that 
which is acting. No difference but that- of 
mere degree will remain between perception and 
memory ; and neither in the one nor in the other 
will the subject be acknowledged to pass beyond 
himself. Restore, on the contrary, the true char 
acter of perception ; recognize in pure perception a 


system of nascent acts which plunges roots deep 
into the real ; and at once perception is seen to be 
radically distinct from recollection ; the reality 
of things is no more constructed or recon 
structed, but touched, penetrated, lived ; and the 
problem at issue between realism and idealism, 
instead of giving rise to interminable metaphysical 
discussions, is solved, or rather dissolved by 

In this way also we shall plainly see what 
position we ought to take up between idealism 
it might an d realism, which are both condemned 
kun g g etan to see in matter only a construc- 
naSreo? 8 ^ on or a reconstruction executed by 
matter - the mind. For if we follow out to the 
end the principle according to which the 
subjectivity of our perception consists, above 
all, in the share taken by memory, we shall say 
that even the sensible qualities of matter would 
be known in themselves, from within and not from 
without, could we but disengage them from that 
particular rhythm of duration which characterizes 
our consciousness. Pure perception, in fact, 
however rapid we suppose it to be, occupies a 
certain depth of duration, so that our successive 
perceptions are never the real moments of things, 
as we have hitherto supposed, but are moments 
of our consciousness. Theoretically, we said, the 
part played by consciousness in external perception 
would be to join together, by the continuous 
thread of memory, instantaneous visions of 


the real. But, in fact, there is for us nothing that 
is instantaneous. In all that goes by that name 
there is already some work of our memory, and 
consequently of our consciousness, which prolongs 
into each other, so as to grasp them in one relatively 
simple intuition, an endless number of moments 
of an endlessly divisible time. Now what is, 
in truth, the difference between matter as the 
strictest realism might conceive it, and the per 
ception which we have of it ? Our perception 
presents us with a series of pictorial, but discon 
tinuous, views of the universe ; from our present 
perceptions we could not deduce subsequent 
perceptions, because there is nothing in an 
aggregate of sensible qualities which foretells 
the new qualities into which they will change. 
On the contrary, matter, as realism usually 
posits it, evolves in such a manner that we can 
pass from one moment to the next by a mathe 
matical deduction. It is true that, between this 
matter and this perception, scientific realism can 
find no point of contact, because it develops 
matter into homogeneous changes in space, while 
it contracts perception into unextended sensa 
tions within consciousness. But, if our hypo 
thesis is correct, we can easily see how perception 
and matter are distinguished, and how they 
coincide. The qualitative heterogeneity of our 
successive perceptions of the universe results from 
the fact that each, in itself, extends over a certain 
depth of duration, and that memory condenses 


in each an enormous multiplicity of vibrations 
which appear to us all at once, although they are 
successive. If we were only to divide, ideally, this 
undivided depth of time, to distinguish in it the 
necessary multiplicity of moments, in a word to 
eliminate all memory, we should pass thereby from 
perception to matter, from the subject to the object. 
Then matter, becoming more and more homo 
geneous as our extended sensations spread them 
selves over a greater number of moments, would 
tend more and more towards that system of homo 
geneous vibrations of which realism tells us, al 
though it would never coincide entirely with them. 
There would be no need to assume, on the one 
hand, space with unperceived movements, and, 
on the other, consciousness with unextended 
sensations. Subject and object would unite in 
an extended perception the subjective side of 
perception being the contraction effected by 
memory, and the objective reality of matter fusing 
with the multitudinous and successive vibrations 
into which this perception can be internally 
broken up. Such at least is the conclusion which, 
we hope, will issue clearly from the last part of 
this essay. Questions relating to subject and object, 
to their distinction and their union, should be put 
in terms of time rather than of space. 

But our distinction between pure perception 
and pure memory has yet another aim. Just 
as pure perception, by giving us hints as to the 


nature of matter, allows us to take an intermediate 
position between realism and idealism, so pure 
memory, on the other hand, by opening to us a 
view of what is called spirit, should enable us to 
decide between those other two doctrines, mater 
ialism and spiritualism. 1 Indeed it is this aspect 
of the subject which will first occupy our atten 
tion in the two following chapters, because it 
is in this aspect that our hypothesis allows some 
degree of experimental verification. 

For it is possible to sum up our conclusions as 
to pure perception by saying that there is in matter 
AS also of the something more than, but not something 
spirit. different from, that which is actually 

given. Undoubtedly conscious perception does not 
compass the whole of matter, since it consists, 
in as far as it is conscious, in the separation, or the 
discernment, of that which, in matter, interests 
our various needs. But between this perception 
of matter and matter itself there is but a differ 
ence of degree and not of kind, pure perception 
standing towards matter in the relation of the 
part to the whole. This amounts to saying that 
matter cannot exercise powers of any kind other 
than those which we perceive. It has no mys 
terious virtue, it can conceal none. To take a 
definite example, one moreover which interests 
us most nearly, we may say that the nervous 

1 The word spiritualism is used throughout this work 
to signify any philosophy that claims for spirit an existence 
of its own. (Translators note.) 


system, a material mass presenting certain quali 
ties of colour, resistance, cohesion, etc., may 
well possess unperceived physical properties, but 
physical properties only. And hence it can have 
no other office than to receive, inhibit, or transmit 

Now the essence of every form of materialism 
is to maintain the contrary, since it holds that 
consciousness, with all its functions, is born of 
the mere interplay of material elements. Hence it 
is led to consider even the perceived qualities 
of matter, sensible, and consequently felt, quali 
ties, as so many phosphorescences which follow 
the track of the cerebral phenomena in the act of 
perception. Matter, thus supposed capable of 
creating elementary facts of consciousness, might 
therefore just as well engender intellectual facts 
of the highest order. It is, then, of the essence 
of materialism to assert the perfect relativity of 
sensible qualities, and it is not without good 
reason that this thesis, which Democritus has 
formulated in precise terms, is as old as 

But spiritualism has always followed mater 
ialism along this path. As if everything lost to 
matter must be gained by spirit, spiritualism has 
never hesitated to despoil matter of the qualities 
with which it is invested in our perception, and 
which, on this view, are subjective appearances. 
Matter has thus too often been reduced to a 
mysterious entity which, just because all we 


know of it is an empty show, might as well 
engender thought as any other phenomenon. 

The truth is that there is one, and only one, 
method of refuting materialism : it is to show 
that matter is precisely that which it appears to be. 
Thereby we eliminate all virtuality, all hidden 
power, from matter, and establish the phenomena 
of spirit as an independent reality. But to do 
this we must leave to matter those qualities 
which materialists and spiritualists alike strip 
from it : the latter that they may make of them 
representations of the spirit, the former that they 
may regard them only as the accidental garb of 

This, indeed, is the attitude of common sense 
with regard to matter, and for this reason com 
mon sense believes in spirit. It seems to us 
that philosophy should here adopt the attitude 
of common sense, although correcting it in one 
respect. Memory, inseparable in practice from 
perception, imports the past into the present, 
contracts into a single intuition many moments 
of duration, and thus by a twofold operation com- 
pells us, de facto, to perceive matter in ourselves, 
whereas we, de jure, perceive matter within matter. 

Hence the capital importance of the problem 
of memory. If it is memory above all that lends 
to perception its subjective character, 
cardinal " the philosophy of matter must aim 
te P pro Sem in the first instance, we said, at elimina 
ting the contributions of memory. We 


must now add that, as pure perception gives us 
the whole or at least the essential part of matter 
(since the rest comes from memory and is super- 
added to matter), it follows that memory must 
be, in principle, a power absolutely independent 
of matter. If, then, spirit is a reality, it is here, 
in the phenomenon of memory, that we may 
come into touch with it experimentally. And 
hence any attempt to derive pure memory from 
an operation of the brain should reveal on analysis 
a radical illusion. 

Let us put the same statement in clearer lan 
guage. We maintain that matter has no occult 

or unknowable power, and that it coin- 
seeing that a . \ 
true theory cides, in essentials, with pure perception, 

refutes mate- Thence we conclude that the living body 

rialism. . 

in general, and the nervous system in 
particular, are only channels for the transmission 
of movements, which, received in the form of 
stimulation, are transmitted in the form of action, 
reflex or voluntary. That is to say, it is vain to 
attribute to the cerebral substance the property 
of engendering representations. Now the pheno 
mena of memory, in which we believe that we 
can grasp spirit in its most tangible form, are pre 
cisely those of which a superficial psychology is 
most ready to find the origin in cerebral activity 
alone ; just because they are at the point of con 
tact between consciousness and matter, and 
because even the adversaries of materialism have 
no objection to treating the brain as a storehouse 


of memories. But if it could be positively estab 
lished that the cerebral process answers only to 
a very small part of memory, that it is rather the 
effect than the cause, that matter is here as else 
where the vehicle of an action and not the sub 
stratum of a knowledge, then the thesis which 
we are maintaining would be demonstrated by 
the very example which is commonly supposed to 
be most unfavourable to it, and the necessity 
might arise of erecting spirit into an independent 
reality. In this way also, perhaps, some light would 
be thrown on the nature of what is called 
spirit, and on the possibility of the interaction of 
spirit and matter. For a demonstration of this 
kind could not be purely negative. Having shown 
what memory is not, we should have to try to 
discover what it is. Having attributed to the 
body the sole function of preparing actions, we are 
bound to enquire why memory appears to be one 
with this body, how bodily lesions influence it, 
and in what sense it may be said to mould itself 
upon the state of the brain matter. It is, more 
over, impossible that this enquiry should fail to 
give us some information as to the psychological 
mechanism of memory, and the various mental 
operations connected therewith. And, inversely, 
if the problems of pure psychology seem to ac 
quire some light from our hypothesis, this 
hypothesis itself will thereby gain in certainty and 

But we must present this same idea in yet a 



third form, so as to make it quite clear why the 
And might problem of memory is in our eyes a 
empiric!? privileged problem. From our analysis 
metap?ycai ^ P ure perception issue two conclu- 
probiems. sions which are in some sort divergent, 
one of them going beyond psychology in the 
direction of psycho-physiology, and the other in 
that of metaphysics, but neither allowing of immed 
iate verification. The first concerns the office of 
the brain in perception : we maintain that the 
brain is an instrument of action, and not of 
representation. We cannot demand from facts 
the direct confirmation of this thesis, because pure 
perception bears, by definition, upon present 
objects, acting on our organs and our nerve centres ; 
and because everything always happens, in conse 
quence, as though our perceptions emanated from 
our cerebral state, and were subsequently pro 
jected upon an object which differs absolutely 
from them. In other words, with regard to 
external perception the thesis which we dispute 
and that which we substitute for it lead to pre 
cisely the same consequences, so that it is possible 
to invoke in favour of either the one or the other 
its greater intelligibility, but not the authority of 
experience. On the contrary, the empirical study 
of memory may and must decide between them. 
For pure recollection is, by hypothesis, the repre 
sentation of an absent object. If the necessary 
and sufficient cause of perception lies in a certain 
activity of the brain, this same cerebral activity, 


repeating itself more or less completely in the 
absence of the object, will suffice to reproduce 
perception : memory will be entirely explicable 
by the brain. But if we find that the cerebral 
mechanism does indeed in some sort condition 
memories, but is in no way sufficient to ensure 
their survival ; if it concerns, in remembered 
perception, our action rather than our repre 
sentation ; we shall be able to infer that it 
plays an analogous part in perception itself, and 
that its office is merely to ensure our effective 
action on the object present. Our first conclusion 
may thus find its verification. There would 
still remain this second conclusion, which is of a 
more metaphysical order, viz. : that in pure per 
ception we are actually placed outside ourselves, 
we touch the reality of the object in an immediate 
intuition. Here also an experimental verifica 
tion is impossible, since the practical results are 
absolutely the same whether the reality of the 
object is intuitively perceived or whether it is 
rationally constructed. But here again a study 
of memory may decide between the two 
hypotheses. For, in the second, there is only a 
difference of intensity, or more generally, of 
degree, between perception and recollection, 
since they are both self-sufficient phenomena 
of representation. But if, on the contrary, we 
find that the difference between perception and 
recollection is not merely in degree, but is a 
radical difference in kind, the presumption will 


be in favour of the hypothesis which finds in per 
ception something which is entirely absent from 
memory, a reality intuitively grasped. Thus 
the problem of memory is in very truth a privi 
leged problem, in that it must lead to the psycho 
logical verification of two theses which appear to 
be insusceptible of proof, and of which the second, 
being of a metaphysical order, appears to go far 
beyond the borders of psychology. 

The road which we have to follow, then, lies 
clear before us. We shall first pass in review 
evidences of various kinds borrowed from normal 
and from pathological psychology, by which 
philosophers might hold themselves justified in 
maintaining a physical explanation of memory. 
This examination must needs be minute or it 
would be useless. Keeping as close as possible 
to facts, we must seek to discover where, in the 
operations of memory, the office of the body begins, 
and where it ends. And should we, in the course 
of this enquiry, find confirmation of our own hypo 
thesis, we shall not hesitate to go further and, 
considering in itself the elementary work of the 
mind, complete the theory thereby sketched out, 
of the relation of spirit with matter. 


.s - 1 


WE pass now to the consideration of the conse 
quences for the theory of memory, which might 
The two ensue from the acceptance of the prin- 
memory : the ciples we have laid down. We have 
as a bodily said that the body, placed between the 

habit, or as 1-1 , j , * 

an indepen- objects which act upon it and those 
lection. which it influences, is only a conductor, 
the office of which is to receive movements, and 
to transmit them (when it does not arrest them) 
to certain motor mechanisms, determined if the 
action is reflex, chosen if the action is volun 
tary. Everything, then, must happen as it an 
independent memory gathered images as they 
successively occur along the course of time ; 
and as if our body, together with its surround 
ings, was never more than one among these 
images, the last, that which we obtain at any mo 
ment by making an instantaneous section in the 
general stream of becoming. In this section our 
body occupies the centre. The things which 
surround it act upon it, and it reacts upon them. 
Its reactions are more or less complex, more or 


less varied, according to the number and nature 
ot the apparatus which experience has set up 
within it. Therefore in the form of motor contri 
vances, and of motor contrivances only, it can 
store up the action of the past. Whence it 
results that past images, properly so called, must 
be otherwise preserved ; and we may formulate 
this first hypothesis : 

I. The past survives under two distinct forms : 
first, in motor mechanisms ; secondly, in indepen- 
pendent recollections. 

But then the practical, and consequently the 
usual function of memory, the utilizing of past 
experience for present action, recognition, in 
short, must take place in two different ways. 
Sometimes it lies in the action itself, and in the 
automatic setting in motion of a mechanism 
adapted to the circumstances ; at other times it 
implies an effort of the mind which seeks in the 
past, in order to apply them to the present, those 
representations which are best able to enter into 
the present situation. Whence our second pro 
position : 

II. The recognition of a present object is effected 
by movements when it proceeds from the object, by 
representations when it issues from the subject. 

It is true that there remains yet another ques 
tion : how these representations are preserved, 
and what are their relations with the motor me 
chanisms. We shall go into this subject thor 
oughly in our next chapter, after we have con- 


sidered the unconscious, and shown where the 
fundamental distinction lies between the past 
and the present. But already we may speak of 
the body as an ever advancing boundary between 
the future and the past, as a pointed end, 
which our past is continually driving forward 
into our future. Whereas my body, taken at a 
single moment, is but a conductor interposed 
between the objects which influence it and those 
on which it acts, it is, on the other hand, when 
replaced in the flux of time, always situated at 
the very point where my past expires in a deed. 
And, consequently, those particular images which 
I call cerebral mechanisms terminate at each 
successive moment the series of my past representa 
tions, being the extreme prolongation of those 
representations into the present, their link with 
the real, that is, with action. Sever that link, and 
you do not necessarily destroy the past image, 
but you deprive it of all means of acting upon 
the real and consequently, as we shall show, of 
being realized. It is in this sense, and in this 
sense only, that an injury to the brain can abolish 
any part of memory. Hence our third, and last, 
proposition : 

III. We pass, by imperceptible stages, from 
recollections strung out along the course of time to 
the movements which indicate their nascent or pos 
sible action in space. Lesions of the brain may affect 
these movements, but not these recollections. 


We have now to see whether experience verifies 
these three propositions. 

I. The two forms of memory. I study a lesson, 
and in order to learn it by heart I read it a first 
time, accentuating every line ; I then repeat it a 
certain number of times. At each repetition 
there is progress ; the words are more and more 
linked together, and at last make a continuous 
whole. When that moment comes, it is said that 
I know my lesson by heart, that it is imprinted 
on my memory. 

I consider now how the lesson has been learnt, 
and picture to myself the successive phases of 
the process. Each several reading then recurs 
to me with its own individuality ; I can see it 
again with the circumstances which attended it 
then and still form its setting. It is distinguished 
from those which preceded or followed it by the 
place which it occupied in time ; in short, each 
reading stands out before my mind as a definite 
event in my history. Again it will be said that 
these images are recollections, that they are im 
printed on my memory. The same words, then, 
are used in both cases. Do they mean the same 
thing ? 

The memory of the lesson, which is remembered 
in the sense of learnt by heart, has all the marks 
of a habit. Like a habit, it is acquired by the 
repetition of the same effort. Like a habit, it 
demands first a decomposition and then a recom- 


position of the whole action. Lastly, like every 
habitual bodily exercise, it is stored up 

To learn by . ; . J 

heart is to in a mechanism which is set in motion 
cerebral as a whole by an initial impulse, in a 
a habit of closed system of automatic movements 

which succeed each other in the same 
order and, together, take the same length of time. 
The memory of each several reading, on the 
contrary, the second or the third for instance, 

has none of the marks of a habit. 

To recall the . . 

successive Its image was necessarily imprinted 

stages of . J 

learning by at once on the memory, since the 

heart is to . . , . . 

appeal to an other readings form, by their very de- 
independent . . . . ... 

memory. nnition, other recollections. It is like 

an event in my life ; its essence is to bear a date, 
and consequently to be unable to occur again. 
All that later readings can add to it will only 
alter its original nature ; and though my effort 
to recall this image becomes more and more easy 
as I repeat it, the image, regarded in itself, was 
necessarily at the outset what it always will 

It may be urged that these two recollections, 
that of the reading and that of the lesson, differ 
only as the less from the more, and that the images 
successively developed by each repetition overlie 
each other, so that the lesson once learned is but 
the composite image in which all readings are 
blended. And I quite agree that each of the 
successive readings differs from the preceding 
mainly in the fact that the lesson is better known. 


But it is no less certain that each of them, con 
sidered as a new reading and not as a lesson better 
known, is entirely sufficient to itself, subsists ex 
actly as it occurred, and constitutes with all its 
concomitant perceptions an original moment of 
my history. We may even go further and aver 
that consciousness reveals to us a profound differ 
ence, a difference in kind, between the two sorts 
of recollection. The memory of a given reading 
is a representation, and only a representation ; 
it is embraced in an intuition of the mind which 
I may lengthen or shorten at will ; I assign to it 
any duration I please ; there is nothing to prevent 
my grasping the whole of it instantaneously, as in 
one picture. On the contrary, the memory of the 
lesson I have learnt, even if I repeat this lesson 
only mentally, requires a definite time, the time 
necessary to develop one by one, were it only in 
imagination, all the articulatory movements that 
are necessary : it is no longer a representation, 
it is an action. And, in fact, the lesson once 
learnt bears upon it no mark which betrays its 
origin and classes it in the past ; it is part of 
my present, exactly like my habit of walking or 
of writing ; it is lived and acted, rather than 
represented: I might believe it innate, if I 
did not choose to recall at the same time, as 
so many representations, the successive readings 
by means of which I learnt it. Therefore these 
representations are independent of it, and, just as 
they preceded the lesson as I now possess and 


know it, so that lesson once learned can do with 
out them. 

Following to the end this fundamental dis 
tinction, we are confronted by two different 
memories theoretically independent. The first 
records, in the form of memory-images, all the 
events of our daily life as they occur in time ; 
it neglects no detail ; it leaves to each fact, 
to each gesture, its place and date. Regardless 
of utility or of practical application, it stores up 
the past by the mere necessity of its own nature. 
By this memory is made possible the intelligent, 
or rather intellectual, recognition of a perception 
already experienced ; in it we take refuge every 
time that, in the search for a particular image, we 
remount the slope of our past. But everypercep- 
Habits ti n is prolonged into a nascent action ; 
EpSted by an d while the images are taking their 
pl ace an( i order in this memory, the 

thesSd d o not movements which continue them modi- 

fy the organism, and create in the body 
new dispositions towards action. Thus 
is gradually formed an experience of an entirely 
different order, which accumulates within the body, 
a series of mechanisms wound up and ready, with 
reactions to external stimuli ever more numerous 
and more varied, and answers ready prepared to an 
ever growing number of possible solicitations. We 
become conscious of these mechanisms as they 
come into play ; and this consciousness of a whole 
past of efforts stored up in the present is indeed 


also a memory, but a memory profoundly differ 
ent from the first, always bent upon action, seated 
in the present and looking only to the future. 
It has retained from the past only the intelli 
gently coordinated movements which represent 
the accumulated efforts of the past ; and it recovers 
those past efforts, not in the memory-images which 
recall them, but in the definite order and systema 
tic character with which the actual movements 
take place. In truth, it no longer represents our 
past to us, it acts it ; and if it still deserves the 
name of memory, it is not because it conserves 
bygone images, but because it prolongs their use 
ful effect into the present moment. 

Of these two memories, of which the one 
imagines and the other repeats, the second may 
such is the su Pply the place of the first and even sometimes be mistaken for it. When a 

welcomes his master, barking and 
recognize*, wagging his tail, he certainly recognizes 
him ; but does this recognition imply the evoca 
tion of a past image and the comparison of that 
image with the present perception ? Does it not 
rather consist in the animal s consciousness of a 
certain special attitude adopted by his body, an 
attitude which has been gradually built up by his 
familiar relations with his master, and which the 
mere perception of his master now calls forth in him 
mechanically ? We must not go too far ; even 
in the animal it is possible that vague images of 
the past overflow into the present perception ; 


we can even conceive that its entire past is vir 
tually indicated in its consciousness ; but this past 
does not interest the animal enough to detach it 
from the fascinating present, and its recognition 
must be rather lived than thought. To call up the 
past in the form of an image, we must be able to 
withdraw ourselves from the action of the moment, 
we must have the power to value the useless, we 
must have the will to dream. Man alone is cap 
able of such an effort. But even in him the past 
to which he returns is fugitive, ever on the point 
of escaping him, as though his backward turning 
memory were thwarted by the other, more natural, 
memory, of which the forward movement bears 
him on to action and to life. 

When psychologists talk of recollection as of a 

fold in a material, as of an impress graven deeper 

by repetition, they forget that the im- 

But true > . r , 

representative mense majority oi our memories bear 

memory re- , , ., ,. ,. , 

cords every upon events and details oi our hie of 

moment 01,.,., . , , , 

duration, which the essence is to have a date, 

each unique, , , , i_i r 

and not to and consequently to be incapable of 

be repeated. , . , ,,,, . , . , 

being repeated. I he memories which 
we acquire voluntarily by repetition are rare 
and exceptional. On the contrary, the record 
ing, by memory, of facts and images unique 
in their kind takes place at every moment of 
duration. But inasmuch as learnt memories are 
more useful, they are more remarked. And as 
the acquisition of these memories by a repetition 
of the same effort resembles the well-known process 


of habit, we prefer to set this kind of memory in 
the foreground, to erect it into the model memory, 
and to see in spontaneous recollection only the 
same phenomenon in a nascent state, the begin 
ning of a lesson learnt by heart. But how can 
we overlook the radical difference between that 
which must be built up by repetition and that 
which is essentially incapable of being repeated ? 
Spontaneous recollection is perfect from the out 
set ; time can add nothing to its image without 
disfiguring it ; it retains in memory its place 
and date. On the contrary, a learnt recollection 
passes out of time in the measure that the lesson 
is better known ; it becomes more and more im 
personal, more and more foreign to our past life. 
Repetition, therefore, in no sense effects the con 
version of the first into the last ; its office is merely 
to utilize more and more the movements by which 
the first was continued, in order to organize 
them together and, by setting up a mechanism, to 
create a bodily habit. Indeed, this habit could 
not be called a remembrance, were it not that I 
remember that I have acquired it ; and I remem 
ber its acquisition only because I appeal to that 
memory which is spontaneous, which dates events 
and records them but once. Of the two memories, 
then, which we have just distinguished, the first 
appears to be memory par excellence. The second, 
that generally studied by psychologists, is habit 
interpreted by memory rather than memory itself. 
It is true that the example of a lesson learnt 


by heart is to some extent artificial. Yet our 
whole life is passed among a limited 

The normal , / 

consciousness number of objects, which pass more or 

calls up only 

those memory- less often before our eyes : each of 

images which . . . , . 

can usefully them, as it is perceived, provokes on 

combine with 

the present our part movements, at least nascent, 
whereby we adapt ourselves to it. These 
movements, as they recur, contrive a mechanism 
for themselves, grow into a habit, and deter 
mine in us attitudes which automatically follow 
our perception of things. This, as we have said, 
is the main office of our nervous system. The 
afferent nerves bring to the brain a disturbance, 
which, after having intelligently chosen its path, 
transmits itself to motor mechanisms created by re 
petition. Thus is ensured the appropriate reaction, 
the correspondence to environment adaptation, 
in a word which is the general aim of life. And 
a living being which did nothing but live would 
need no more than this. But, simultaneously 
with this process of perception and adaptation 
which ends in the record of the past in the form 
of motor habits, consciousness, as we have seen, 
retains the image of the situations through which it 
has successively travelled, and lays them side by 
side in the order in which they took place.. Of 
what use are these memory-images ? Preserved in 
memory, reproduced in consciousness, do they not 
distort the practical character of life, mingling 
dream with reality ? They would, no doubt, if 
our actual consciousness, a consciousness which re- 


fleets the exact adaptation of our nervous system 
to the present situation, did not set aside all those 
among the past images which cannot be co 
ordinated with the present perception and are 
unable to form with it a useful combination. At 
most, certain confused recollections, unrelated 
to the present circumstances, may overflow 
the usefully associated images, making around 
these a less illuminated fringe which fades away 
into an immense zone of obscurity. But sup 
pose an accident which upsets the equilibrium 
maintained by the brain between the external 
stimulation and the motor reaction, relax for a 
moment the tension of the threads which go from 
the periphery to the periphery by way of the 
centre, and immediately these darkened images 
come forward into the full light : it is probably the 
latter condition which is realized in any sleep where 
in we dream. Of these two memories that we have 
distinguished, the second, which is active or motor, 
will, then, constantly inhibit the first, or at least 
only accept from it that which can throw light 
upon and complete in a useful way the present 
situation : thus, as we shall see later, could the 
laws of the association of ideas be explained. 
But, besides the services which they can render 
by associating with the present perception, the 
images stored up in the spontaneous memory 
have yet another use. No doubt they are 
dream-images ; no doubt they usually appear 
and disappear independently of our will ; and 


this is why, when we really wish to know a 
thing, we are obliged to learn it by heart, that is 
to say, to substitute for the spontaneous image a 
motor mechanism which can serve in its stead. 
But there is a certain effort sui generis which 
permits us to retain the image itself, for a limited 
time, within the field of our consciousness ; and, 
thanks to this faculty, we have no need to await 
at the hands of chance the accidental repetition 
of the same situations, in order to organize into a 
habit concomitant movements ; we make use of the 
fugitive image to construct a stable mechanism 
which takes its place. Either, then, our distinction 
of the two independent memories is unsound, or, 
if it corresponds to facts, we shall find an exaltation 
of spontaneous memory in most cases where the 
sensori-motor equilibrium of the nervous system 
is disturbed ; an inhibition, on the contrary, in 
the normal state, of all spontaneous recollections 
which do not serve to consolidate the present 
equilibrium ; and lastly, in the operation by 
means of which we acquire the habit-memory, a 
latent intervention of the image-memory. Let 
us see whether the facts confirm this hypothesis. 
For the moment we will insist on neither point ; 
we hope to throw ample light upon both when 
we study the disturbances of memory and the laws 
of the association of ideas. We shall be content 
for the present to show, in regard to things which 
are learnt, how the two memories run side by side 
and lend to each other a mutual support. It is 


a matter of every-day experience that lessons 
committed to the motor memory can be auto 
matically repeated ; but observation of patho 
logical cases proves that automatism extends 
Therefore much further in this direction than we 
think. In cases of dementia, we some- 
times find that intelligent answers are 
StenSper- given to a succession of questions which 
masked by are not understood : language here works 
habit memory. after ^ manner o f a reflex. 1 Aphasics, 

incapable of uttering a word spontaneously, can 
recollect without a mistake the words of an air 
which they sing. 1 Or again, they will fluently 
repeat a prayer, a series of numbers, the days of 
the week, or the months of the year. 8 Thus 
extremely complex mechanisms, subtle enough to 
imitate intelligence, can work by themselves when 
once they have been built up, and in consequence 
usually obey a mere initial impulse of the will. 
But what takes place while they are being built 
up ? When we strive to learn a lesson, for in 
stance, is not the visual or auditory image which 
we endeavour to reconstitute by movements 
already in our mind, invisible though present ? 
Even in the very first recitation, we recognize, 

1 Robertson, Reflex Speech (Journal of Mental Science, 
April, 1888). Cf. the article by Ch. Fe re , Le langage reflexe 
(Revue Philosophique, Jan. 1896). 

1 Oppenheim, Ueber das Verhalten der musikalischen Aus- 
drucksbewegungen bei Aphatischen (Charite Annalen, xiii, 
1888, p. 348 et seq.). 

8 Ibid., p. 365. 


by a vague feeling of uneasiness, any error we 
have made, as though from the obscure depths 
of consciousness we received a sort of warn 
ing. 1 Concentrate your mind on that sensation, 
and you will feel that the complete image is there, 
but evanescent, a phantasm that disappears just 
at the moment when motor activity tries to fix 
its outline. During some recent experiments 
(which, however, were undertaken with quite a 
different purpose), 2 the subjects averred that they 
felt just such an impression. A series of letters, 
which they were asked to remember, was held 
before their eyes for a few seconds. But, to pre 
vent any accentuating of the letters so perceived 
by appropriate movements of articulation, they 
were asked to repeat continuously a given syl 
lable while their eyes were fixed on the image. 
From this resulted a special psychical state ; 
the subjects felt themselves to be in complete 
possession of the visual image, although unable to 
produce any part of it on demand : to their great 
surprise the line disappeared. According to one 
observer, the basis was a Gesammtvorstellung, a 
sort of all-embracing complex idea in which the 
parts have an indefinitely felt unity. 3 

1 See, on the subject of this sense of error, the article by 
Miiller and Schumann, Experimentelle Beitrdge zur Untersu- 
chung des Geddcthtnisses (Zeitschr. /. Psych, u. Phys. der 
Sinnesorgane (Dec., 1893, p. 305). 

2 W. G. Smith, The Relation of A ttentionto Memory. (Mind, 
Jan. 1895.) 

8 Ibid. loc. cit., p. 23. 


This spontaneous recollection, which is masked 
by the acquired recollection, may flash out at 
intervals ; but it disappears at the least move 
ment of the voluntary memory. If the subject 
sees the series of letters, of which he thought he 
retained the image, vanish from before his eyes, 
this happens mainly when he begins to repeat it : 
the effort seems to drive the rest of the image out 
of his consciousness. 1 Now, analyse many of the 
imaginative methods of mnenomics and you will 
find that the object of this science is to bring into 
the foreground the spontaneous memory which 
was hidden, and to place it, as an active memory, 
at our service ; to this end every attempt at 
motor memory is, to begin with, suppressed. 
The faculty of mental photography, says one 
author, 2 belongs rather to subconsciousness than 

1 Something of this nature appears to take place in that 
affection which German authors call Dyslexic. The patient 
reads the first words of a sentence aright, and then stops 
abruptly, unable to go on, as though the movements of 
articulation had inhibited memory. See, on the subject 
of dyslexic : Berlin, Eine besondere Art der Wortblindheit 
(Dyslexie), Wiesbaden, 1887, and Sommer, Die Dyslexic 
als functionelle Storung (Arch. f. Psychiatrie, 1893). We may 
also compare with these phenomena the remarkable cases 
of word deafness in which the patient understands the 
speech of others, but no longer understands his own. (See 
examples cited by Bateman, On Aphasia, p. 200 ; by Bernard, 
De I aphasie, Paris 1889, pp. 143 and 144 ; and by Broadbent, 
Case of Peculiar Affection of Speech, Brain, 1878-9, p. 484 et 

2 Mortimer Granville, Ways of remembering. (Lancet, Sept. 
27. 1899, p. 458.; 


to consciousness ; it answers with difficulty to 
the summons of the will. In order to exercise it, 
we should accustom ourselves to retaining, for 
instance, several arrangements of points at once, 
without even thinking of counting them x : we 
must imitate in some sort the instantaneity of 
this memory in order to attain to its mastery. 
Even so it remains capricious in its manifesta 
tions ; and as the recollections which it brings us 
are akin to dreams, its more regular intrusion 
into the life of the mind may seriously disturb 
intellectual equilibrium. 

What this memory is, whence it is derived and 
how it works, will be shown in the next chapter. 
For the moment, the schematic conception will 
be enough. So we shall merely sum up the pre 
ceding paragraphs and say that the past appears 
indeed to be stored up, as we had surmised, under 
two extreme forms : on the one hand, motor 
mechanisms which make use of it ; on the other, 
personal memory-images which picture all past 
events with their outline, their colour and their 
place in time. Of these two memories the first 
follows the direction of nature ; the second, left 
to itself, would rather go the contrary way. 
The first, conquered by effort, remains depen- | 
dent upon our will ; the second, entirely spon 
taneous, is as capricious in reproducing as it 
is faithful in preserving. The only regular and 

1 Kay, Memory and how to improve it. New York, 1888. 


certain service which the second memory can 
render to the first is to bring before it images of 
what preceded or followed situations similar to 
the present situation, so as to guide its choice : 
in this consists the association of ideas. There 
is no other case in which the memory which recalls 
is sure to obey the memory which repeats. Every 
where else, we prefer to construct a mechanism 
which allows us to sketch the image again, at 
need, because we are well aware that we cannot 
count upon its reappearance. These are the two 
extreme forms of memory in their pure state. 

Now we may say at once that it is because 
philosophers have concerned themselves only with 
the intermediate and, so to speak, impure forms 
Thus memory- ^ na * they have misunderstood the true 
l motlr Kbit nature of memory. Instead of dis- 
" e k d i!?d? ct sociating the two elements, memory- 
m^ooaieMe i ma ge and movement, in order to dis- 
Sn^why^**" cover subsequently by what series of 
SreISiiSo r operations they come, having each aban- 
is necessary. d O ned some part of its original purity 
to fuse one with the other, they are apt to consider 
only the mixed phenomenon which results from 
their coalescence. This phenomenon, being mixed, 
presents on the one side the aspect of a motor 
habit, and on the other that of an image more or less 
consciously localized. But they will have it that the 
phenomenon is a simple one. So they must assume 
that the cerebral mechanism, whether of the brain 
or of the medulla oblongata or of the cord, which 


serves as the basis of the motor habit, is at the 
same time the substratum of the conscious image. 
Hence the strange hypothesis of recollections stored 
in the brain, which are supposed to become con 
scious as though by a miracle, and bring us back 
to the past by a process that is left unexplained. 
True, some observers do not make so light of 
the conscious aspect of the operation, and see 
in it something more than an epiphenomenon. 
But, as they have not begun by isolating the 
memory which retains and sets out the successive 
repetitions side by side in the form of memory 
images, since they confound it with the habit which 
is perfected by use, they are led to believe that the 
effect of repetition is brought to bear upon one and 
the same single and indivisible phenomenon which 
merely grows stronger by recurrence : and, as this 
phenomenon clearly ends by being merely a motor 
habit corresponding to a mechanism, cerebral or 
other, they are led, whether they will or no, to sup 
pose that some mechanism of this kind was from the 
beginning behind the image and that the brain is an 
organ of representation. We are now about to con 
sider these intermediate states, and distinguish in 
each of them the part which belongs to nascent 
action, that is to say of the brain, and the part of 
independent memory, that is to say of memory- 
images. What are these states ? Being partly motor 
they must, on our hypothesis, prolong a present 
perception ; but, on the other hand, inasmuch as 
they are images, they reproduce past perceptions. 


Now the concrete process by which we grasp the 
past in the present is recognition. Recognition, 
therefore, is what we have to study, to begin 

II. Of recognition in general : memory-images 

and movements. There are two ways in which 

it is customary to explain the feeling of 

What then , . j.u- V * i r\ 

is recogni- having seen a thing before. On one 

tionP ? r 

theory, the recognition of a present 
perception consists in inserting it mentally in its 
former surroundings. I encounter a man for the 
first time : I simply perceive him. If I meet him 
again, I recognize him, in the sense that the 
concomitant circumstances of the original per 
ception, returning to my mind, surround the 
actual image with a setting which is not a 
setting actually perceived. To recognize, then, 
according to this theory, is to associate with a 
present perception the images which were for 
merly given in connexion with it. 1 But, as it 
has been justly observed, a renewed perception 
cannot suggest the concomitant circumstances 
of the original perception unless the latter is 
evoked, to begin with, by the present state which 
resembles it. 2 Let A be the first perception ; 

1 See the systematic treatment of this thesis, supported 
by experiments, in Lehmann s articles, Ueber Wieder- 
erkennen (Philos. Studien Wundt, vol. v, p. 96 et seq., and 
vol. vii, p. 169 et seq.). 

2 Pillon, La formation des idees abstraites et generates (Crit. 


the accompanying circumstances B, C, D, remain 
associated with it by contiguity. If I call the 
same perception renewed A , as it is not with 
A , but with A that the terms B, C, D are bound 
up, it is necessary, in order to evoke the terms 
B, C, D, that A should be first called up by some 
association of resemblance. And it is of no use to 
assert that A is identical with A. For the two terms, 
though similar, are numerically distinct, and differ 
at least by this simple fact that A is a perception, 
whereas A is but a memory. Of the two interpre 
tations of which we have spoken, the first, then, 
melts into the second, which we will now examine. 
It is alleged that the present perception dives 
it is not a ^ n ^ * ne depths of memory in search of the 
oTperceptfon remembrance of the previous perception 
and memory. w hi c h resembles it : the sense of recog 
nition would thus come from a bringing together, 
or a blending, of perception and memory. No 
doubt, as an acute thinker l has already pointed 
out, resemblance is a relation established by 
the mind between terms which it compares 
and consequently already possesses ; so the 
perception of a resemblance is rather an effect 
of association than its cause. But, along with 
this definite and perceived resemblance which 

Philos. 1885, vol i, p. 208 et seq.). Cf. Ward, Assimilation 
and Association (Mind, July 1893 and Oct. 1894). 

1 Brochard, La loi de similarite (Revue Philosophique , 1880, 
vol. ix, p. 258). M. Rabier shows himself also of this opinion 
in his Lemons de Philosophic, vol. i, Psychologie, pp. 187-192. 


consists in the common element seized and disen 
gaged by the mind, there is a vague and in some 
sort objective resemblance, spread over the sur 
face of the images themselves, which might act 
perhaps like a physical cause of reciprocal attrac 
tion. 1 And should we ask how it is, then, that 
we often recognize an object without being able 
to identify it with a former image, refuge is 
sought in the convenient hypothesis of cerebral 
tracks which coincide with each other, of cerebral 
movements made easier by practice, 2 or of percep 
tive cells communicating with cells where memories 
are stored. 8 In truth, all such theories of recog 
nition are bound to melt away, in the end, into 
physiological hypotheses of this kind. What they 
were aiming at, first, was to make all recog 
nition issue from a bringing together of per 
ception and memory ; but experience stands 
over against them, testifying that in most cases 
recollection emerges only after the perception 
is recognized. So they are sooner or later 
forced to relegate to the brain, in the form of a 
combination between movements or of a connexion 
between cells, that which they had first declared 
to be an association of ideas ; and to explain the 

1 Pillon, loc. tit., p. 207. Cf. James Sully, The human 
Mind, London, 1892, vol. i, p. 331. 

2 H off ding, Ueber Wiedererkennen, Association und psy- 
chische Activitdt (Vierteljahresschrift /. wissenschaftlichc Philo 
sophic, 1889, p. 433. 

8 Munk, Ueber die Functiontn der Grosshirnrwde. Berlin, 
1881, p. 108 et seq. 


fact of recognition, very clear on our view by 
the hypothesis, which seems to us very obscure, of 
a brain which stores up ideas. 

But the fact is that the association of a perception 
with a memory is not enough to account for the 
process of recognition. For if recognition took place 
in this way, it would always be obliterated when 
the memory images had disappeared, and always 
happen when these images are retained. Psychic 
blindness, or the inability to recognize perceived 
objects, would, then, never occur without an inhibi 
tion of visual memory ; and, above all, the inhibi 
tion of visual memory would invariably produce 
psychic blindness. But neither consequence is 
borne out by facts. In a case studied by Wil- 
brand, 1 the patient could describe with her eyes 
shut the town she lived in and, in imagination, 
walk through its streets : yet, once in the street, 
she felt like a complete stranger ; she recognized 
nothing and could not find her way. Facts of the 
same kind have been observed by Fr. Miiller 2 and 
Lissauer: 3 the patients can summon up the 
mental picture of an object named to them ; they 
describe it very well ; but they cannot recognize 
it when it is shown to them. The retention, even 
the conscious retention, of a visual memory is, 

1 Die Seelenblindheit als Herderscheinung, Wiesbaden, 
1887, p. 56. 

2 Ein Beitrag zur Kennlniss der Seelenblindheit (Arch. /. 
Psychiatrie, vol. xxiv, 1892. 

8 Em Fall von Seelenblindheit (Arch. /. Psychiatrie, 1889). 


therefore, not enough for the recognition of a simi 
lar perception. Inversely, in Charcot s case, which 
has become the classic example of a complete 
eclipse of visual images, 1 not all recognition of 
perceptions was obliterated. A careful study of the 
report of the case is conclusive on this point. No 
doubt the patient failed to recognize the streets and 
houses of his native town, to the extent of being 
unable to name them or to find his way about 
them ; yet he knew that they were streets and 
houses. He no longer recognized his wife and chil 
dren ; yet, when he saw them, he could say that 
this was a woman, that those were children. None 
of this would have been possible, had there been 
psychic blindness in the absolute sense of the 
word. A certain kind of recognition, then, which 
we shall need to analyse, was obliterated, not the 
general faculty of recognition. So we must conclude 
that not every recognition implies the intervention 
of a memory image ; and, conversely, that we 
may still be able to call up such images when we 
have lost the power of identifying perceptions 
with them. What then is recognition, and how 
shall we define it ? 

There is, in the first place, if we carry the 
process to the extreme, an instantaneous recogni 
tion, of which the body is capable by itself, 
without the help of any explicit memory-image. It 

1 Reported by Bernard, Un cas de suppression brusque et 
isolee de la vision mentale (Progres Medical, July 21, 1883). 


consists in action and not in representation, 
in one kind of For instance, I take a walk in a town 

fheS Sf seen then for the first time - At ever Y 
fami S iiar S uy L street corner I hesitate, uncertain where 
n h es S C oT cion8 " ! am g m g- I am in doubt ; and I 
m e oto? r ao- ed mean by this that alternatives are offered 
companiment. to my body, that my movement as a 
whole is discontinuous, that there is nothing in one 
attitude which foretells and prepares future atti 
tudes. Later, after prolonged sojourn in the town, 
I shall go about it mechanically, without having any 
distinct perception of the objects which I am 
passing. Now, between these two extremes, the one 
in which perception has not yet organized the 
definite movements which accompany it, and the 
other in which these accompanying movements are 
organized to a degree which renders perception 
useless, there is an intermediate state in which 
the object is perceived, yet provokes movements 
which are connected, continuous and called up 
by one another. I began by a state in which I 
distinguished only my perception ; I shall end 
in a state in which I am hardly conscious of 
anything but automatism : in the interval there 
is a mixed state, a perception followed step by 
step by automatism just impending. Now, if 
the later perceptions differ from the first percep 
tion in the fact that they guide the body towards 
the appropriate mechanical reaction, if, on the 
other hand, those renewed perceptions appear to 
the mind under that special aspect which charac- 


terizes familiar or recognized perceptions, must 
we not assume that the consciousness of a well- 
regulated motor accompaniment, of an organized 
motor reaction, is here the foundation of the sense 
of familiarity ? At the basis of recognition there 
would thus be a phenomenon of a motor order. 

To recognize a common object is mainly to 
know how to use it. This is so true that early 
observers gave the name apraxia to that failure 
of recognition which we call psychic blindness. 1 
But to know how to use a thing is to sketch 
out the movements which adapt themselves to 
it ; it is to take a certain attitude, or at least 
to have a tendency to do so through what 
the Germans call motor impulses (Bewegungs- 
antriebe). The habit of using the object has, 
then, resulted in organizing together movements 
and perceptions ; and the consciousness of these 
nascent movements, which follow perception after 
the manner of a reflex, must be here also at the 
bottom of recognition. 

There is no perception which is not prolonged 
into movement. Ribot 2 and Maudsley 8 long 
since drew attention to this point. The training of 

1 Kussmaul, Die Storungen der Sprache, p. 181. Allen 
Starr, Apraxia and Aphasia (Medical Record, Oct. 27, 1888). 
Cf. Laquer, Zur Localisation der Sensorischen Aphasie 
(Neurolog. Centralblati, June 15, 1888), and Dodds, On some 
central affections of vision (Brain, 1885). 

2 Les mouvemcnts, et leur importance psychologique (Revue 
Philosophique,i8jg, vol. viii, p. 271 et seq.). Cf. Psychologic 
de Vattention, Paris, 1889, p. 75. 

a Physiology of Mind, p. 206 et seq. 


the senses consists in just the sum of the connexions 
established between the sensory impression and the 
movement which makes use of it. As the impression 
is repeated, the connexion is consolidated. Nor is 
there anything mysterious in the mechanism of 
the operation. Our nervous system is evidently 
arranged with a view to the building up of motor 
apparatus linked, through the intermediary of cen 
tres, with sense stimuli ; and the discontinuity of 
the nervous elements, the multiplicity of their 
terminal branches, which are probably capable of 
joining in various ways, make possible an unlimited 
number of connexions between impressions and 
the corresponding movements. But the mechan 
ism in course of construction cannot appear to 
consciousness in the same form as the mechan 
ism already constructed. There is something 
which profoundly distinguishes and clearly mani 
fests those systems of movements which are consoli 
dated in the organism ; and that is, we believe, 
the difficulty we have in modifying their order. 
It is, again, the preformation of the movements 
which follow in the movements which precede, 
a preformation whereby the part virtually con 
tains the whole, as when each note of a tune learnt 
by heart seems to lean over the next to watch 
its execution. 1 If, then, even* perception has 

1 In one of the mo<t ingenious chapters of his Psychologic 
(Paris, 1893, vol. i, p. -42 . Fouillee says that the sense of 
familiarity is largely due to the diminution of the inward 
sJtock which constitutes surprise. 


its organized motor accompaniment, the ordinary 
feeling of recognition has its root in the conscious 
ness of this organization. 

In fact, we commonly act our recognition before 
we think it. Our daily life is spent among objects 
whose very presence invites us to play a part : in 
this the familiarity of their aspect consists. Motor 
tendencies would, then, be enough by themselves to 
give us the feeling of recognition. But we hasten to 
add that in most cases there is something else besides. 

For, while motor apparatus are built up under 
the influence of perceptions that are analysed 
And these with increasing precision by the body, 
SS e tS our P ast psychical life is there : it 
Semory a - moilg survives as we shall try to prove- 
mem-toZ with all the detail of its events local- 
ges intervene. j ze( j i n time. Always inhibited by 
the practical and useful consciousness of the 
present moment, that is to say, by the sensori- 
motor equilibrium of a nervous system con 
necting perception with action, this memory 
merely awaits the occurrence of a rift between 
the actual impression and its corresponding 
movement to slip in its images. As a rule, 
when we desire to go back along the course of the 
past and discover the known, localized, personal 
memory-image which is related to the present, 
an effort is necessary, whereby we draw back from 
the act to which perception inclines us : the 
latter would urge us towards the future ; we have 
to go backwards into the past. In this sense, 


movement rather tends to drive away the image. 
Yet, in one way, it contributes to its approach. 
For, though the whole series of our past images 
remains present within us, still the representation 
which is analogous to the present perception 
has to be chosen from among all possible repre 
sentations. Movements, accomplished or merely 
nascent, prepare this choice, or at the very least 
mark out the field in which we shall seek the 
image we need. By the very constitution of our 
nervous system, we are beings in whom present 
impressions find their way to appropriate move 
ments : if it so happens that former images can 
just as well be prolonged in these movements, they 
take advantage of the opportunity to slip into the 
actual perception and get themselves adopted by 
it. They then appear, in fact, to our conscious 
ness, though it seems as if they ought, by right, 
to remain concealed by the present state. So 
we may say that the movements which bring about 
mechanical recognition hinder in one way, and 
encourage in another, recognition by images. In 
principle, the present supplants the past. But, on 
the other hand, ]ust because the disappearance of 
former images is due to their inhibition by our 
present attitude, those whose shape might fit 
into this attitude encounter less resistance than 
the others ; and if, then, any one of them is 
indeed able to overcome the obstacle, it is the 
image most similar to the present perception that 
will actually do so. 


If our analysis is correct, the diseases which 
affect recognition will be of two widely differing 
Therefore forms, and facts will show us two kinds 

one kind of 

psychic of psychic blindness. For we may pre- 

blindness may , , . . , . , , 

be due to a sume that, m some cases, it is the mem- 

distnrbance . 1-1 

of motor ory -image which can no longer reappear, 

habits, not to J . ? 

the loss of and that, in other cases, it is merely 
images. the bond between perception and 
the accompanying habitual movements which is 
broken, perception provoking diffused move 
ments, as though it were wholly new. Do the facts 
confirm this hypothesis ? 

There can be no dispute as to the first point. 
The apparent abolition of visual memory in psychic 
blindness is so common a fact that it served, fora 
time, as a definition of that disorder. We shall 
have to consider how far, and in what sense, mem 
ories can really disappear. What interests us for 
the moment is that cases occur in which there is no 
recognition and yet visual memory is not altogether 
lost. Have we here then, as we maintain, merely 
a disturbance of motor habits, or at most an inter 
ruption of the chain which unite them to sense 
perceptions ? As no observer has considered a 
question of this nature, we should be hard put to 
it for an answer if we had not noticed here and 
there in their descriptions certain facts which 
appear to us significant. 

The first of these facts is the loss of the sense of 
direction. All those who have treated the subject 
of psychic blindness have been struck bythispecu- 


liarity. Lissauer s patient had completely lost the 
faculty of finding his way about his own house. 1 
Fr. Miiller insists on the fact that, while blind men 
soon learn to find their way, the victim of psychic 
blindness fails, even after months of practice, to 
find his way about his own room. 2 But is not this 
faculty of orientation the same thing as the faculty 
of coordinating the movements of the body with 
the visual impression, and of mechanically prolong 
ing perceptions in useful reactions ? 

There is a second, and even more characteristic 
fact, and that is the manner in which these patients 
draw. We can conceive two fashions of drawing. 
In th^ first we manage, by tentative efforts, to 
set down here and there on the paper a certain 
number of points, and we then connect them 
together, verifying continually the resemblance 
between the drawing and the object. This is 
what is known as point to point drawing. But 
our habitual method is quite different. We draw 
with a continuous line, after having looked at, or 
thought of, our model. How shall we explain such 
a faculty, except by our habit of discovering at once 
the organization of the outlines of common objects, 
that is to say, by a motor tendency to draft 
their diagram in one continuous line ? But if it is 

1 Op. cit., Arch. /. Psychiatric, 1889-90, p. 224. Cf. Wil- 
brand, op. cit., p. 140, and Bernhardt, Eigenthiimlichcr Fall 
von Hirnerkrankung (Berliner klinischc Wochenschrift, 1877, 

P- 58i> 

* Op. cit.. Arch. f. Psychiatric, vol. xxiv, p. 


just such habits or correspondences which are lost 
in certain forms of psychic blindness, the patient 
may still perhaps be able to draw bits of a line 
which he will connect together more or less well ; 
but he will no longer be able to draw at a stroke, 
because the tendency to adopt and reproduce the 
general movement of the outline is no longer pre 
sent in his hand. Now this is just what experi 
ment verifies. Lissauer s observations are instruc 
tive on this head. 1 His patient had the greatest 
difficulty in drawing simple objects; and if he 
tried to draw them from memory, he traced de 
tached portions of them chosen at random, and 
was unable to unite these into a whole. Cases 
of complete psychic blindness are, however, rare. 
Those of word-blindness are much more numerous 
cases of a loss, that is, of visual recognition limited 
to the characters of the alphabet. Now it is a fact of 
common observation that the patient, in such cases, 
is unable to seize what may be called the movement 
of the letters when he tries to copy them. He 
begins to draw them at any point, passing back 
and forth between the copy and the original to 
make sure that they agree. And this is the more 
remarkable in that he often retains unimpaired 
the faculty of writing from dictation or spon 
taneously. What is lost is clearly the habit of 
distinguishing the articulations of the object per 
ceived, that is to say, of completing the visual 

1 Op. cit., Arch, f. Psychiatric, 1889-90, p. 233. 


perception by a motor tendency to sketch its 
diagram. Whence we may conclude that such 
is indeed the primordial condition of recogni 

But we must pass now from automatic recog 
nition, which is mainly achieved through move 
ments, to that which requires the regular interven 
tion of memory- images. The first is recognition by 
^attention ; the second, as we shall see, is attentive 

This form also begins by movements. But, 
whereas, in automatic recognition, our movements 
prolong our perception in order to draw from 
it useful effects and thus take us away from the 
object perceived, here, on the contrary, they bring 
us back to the object, to dwell upon its outlines. 
Thus is explained the preponderant, and no longer 
merely accessory, part taken here by memory- 
images. For if we suppose that the movements 
forego their practical end, and that motor activity, 
instead of continuing perception by useful reactions, 
turns back to mark out its more striking features, 
then the images which are analogous to the pre 
sent perception, images of which these movements 
have already sketched out, so to speak, the form, 
will come regularly, and no longer accidentally, to 
flow into this mould, though they may have to give 
up much of their detail in order to get in more 

///. Gradual passage of recollections into move- 


ments. Recognition and attention. Here we come 
Transition to to the essential point of our discussion. 
recognition. ^ n those cases where recognition is 
biem oTattSi- attentive, i.e. where memory-images 
co nsi s d h eted d be are regularly united with the present 
perception, is it the perception which 
t e o Ct the determines mechanically the appearance 
brain. o f ^ e memories, or is it the memories 

which spontaneously go to meet the perception ? 

On the answer to this question will depend the 
nature of the relation which philosophers will have 
to establish between the brain and memory. For 
in every perception there is a disturbance communi 
cated by the nerves to the perceptive centres. If 
the passing on of this movement to other cortical 
centres had, as its real effect, the upspringing of 
images in these, then we might in strictness main 
tain that memory is but a function of the brain. 
But if we can establish that here, as elsewhere, 
movement produces nothing but movement, that 
the office of the sense-stimulation is merely to 
impress on the body a certain attitude into which 
recollections will come to insert themselves, then, 
as it would be clear that the whole effect of 
the material vibrations is exhausted in this work 
of motor adaptation, we should have to look for 
memory elsewhere. On the first hypothesis, the 
disorders of memory occasioned by a cerebral 
lesion would result from the fact that the recol 
lections occupied the damaged region and were 
destroyed with it. On the second, these lesions 


would affect our nascent or possible action, but 
our action alone. Sometimes they would hinder 
the body from taking, in regard to the object, the 
attitude that may call back its memory-image ; 
sometimes they would sever the bonds between 
remembrance and the present reality ; that is, 
by suppressing the last phase of the realization 
of a memory the phase of action they would 
thereby hinder the memory from becoming actual. 
But in neither case would a lesion of the brain 
really destroy memories. 

The second hypothesis is ours ; but, before we 
attempt to verify it, we must briefly state how 
we understand the general relations of percep 
tion, attention and memory. In order to show 
how a memory may, by gradual stages, come to 
graft itself on an attitude or a movement, we 
shall have to anticipate in some degree the con 
clusions of our next chapter. 

What is attention ? In one point of view the 

essential effect of attention is to render perception 

more intense, and to spread out its 

flrilran 11 ** details ; regarded in its content, it would 

*he P body. n ! resolve itself into a certain magnifying 

Se ively>it of the intellectual state. 1 But, on the 

movement * ^her hand, consciousness testifies to an 

irreducible difference of form between 

1 Marillier, Remarqucs sur le mecanisme de I altention 
(Revue Philosophique, 1889, vol. xxvii). Cf. Ward, art. 
PSYCHOLOGY in the Encyclopaedia Briiannica ; and Bradley, 
Is there a Special Activity of Attention? (Mind, 1886, vol. xi, 
P. 3050 


this increase of intensity and that which is owing 
to a higher power of the external stimulus : it 
seems indeed to come from within, and to indicate 
a certain attitude adopted by the intellect. But 
just here begins the difficulty, for the idea of 
an intellectual attitude is not a clear idea. Psy 
chologists will here speak of a concentration of 
the mind/ 1 or again of an apperceptive a 
effort to bring perception into the field of distinct 
intelligence. Some of them, materializing this 
idea, will suppose a higher tension of cerebral 
energy, 3 or even the setting free of a certain amount 
of central energy which reinforces the stimulation 
received. 4 But either the fact observed psy 
chologically is merely translated thereby into a 
physiological symbolism which seems to us even less 
clear, or else we always come back to a metaphor. 
Stage by stage we shall be led on to define atten 
tion as an adaptation of the body rather than of the 
mind, and to see in this attitude of consciousness 
mainly the consciousness of an attitude. Such 
is the position assumed by Ribot 6 in the 
discussion, and, though it has been attacked,* 

1 Hamilton, Lectures on Metaphysics, vol. i, p. 247. 

2 Wundt, Grundziige der physiologischen Psychologic, 
vol. iii, p. 331 et seq. 

3 Maudsley, Physiology of Mind, p. 299. Cf. Bastian, 
Les processus nerueux dans I attention (Revue Philosophique, 
vol. xxxiii, p. 360 et seq.). 

4 W. James, Principles of Psychology, vol. i, p. 441. 
6 Psychologie de I attention, Paris, 1889. 

Marillier, op. cit. Cf. J. Sully, The Psycho- physical 
Process in Attention (Brain, 1890, p. 154). 


it appears to have retained all its strength, pro 
vided, however, that we are content to see, in 
the movements described by Ribot, only 
the negative condition of the phenomenon. For, 
even if we suppose that the accompanying move 
ments of voluntary attention are mainly move 
ments of arrest, we still have to explain the accom 
panying work of the mind, that is to say, the 
But the mysterious operation by which the same 

positive ride ..... , 

of attention organ, perceiving in the same surround- 

is the effort ., , . ,. . , 

which seeks ings the same object, discovers in it 

past memory- . , . . 

images to a growing number of things. But we 

insert them , ,. 

into the may go farther, and maintain that the 
perception, phenomena of inhibition are merely a 
preparation for the actual movements of volun 
tary attention. Suppose for a moment that atten 
tion, as we have already suggested, implies a 
backward movement of the mind which thus gives 
up the pursuit of the useful effect of a present per 
ception : there will indeed be, first, an inhibition 
of movement, an arresting action. But, upon this 
general attitude, more subtle movements will 
soon graft themselves, some of which have been 
already remarked and described, 1 and all of which 
combine to retrace the outlines of the object 
perceived. With these movements the positive, 
no longer merely negative, work of attention 
begins. It is continued by memories. 

For, while external perception provokes on our 

1 N. Lange, Beitr. zur Theorie der Sinnlichen Aufmerk- 
samkeit (Philos. Studien, Wundt, vol. vii, pp. 390-422). 


part movements which retrace its main lines, our 
memory directs upon the perception received the 
memory-images which resemble it and which are 
already sketched out by the movements themselves. 
Memory thus creates anew the present perception ; 
or rather it doubles this perception by reflecting 
upon it either its own image or some other memory- 
image of the same kind. If the retained or 
remembered image will not cover all the details of 
the image that is being perceived, an appeal is made 
to the deeper and more distant regions of memory, 
until other details that are already known come to 
project themselves upon those details that remain 
unperceived. And the operation may go on in 
definitely; memory strengthening and enriching 
perception, which, in its turn becoming wider, 
draws into itself a growing number of comple 
mentary recollections. So let us no longer think 
of a mind which disposes of some fixed quantity 
of light, now diffusing it around, now concen 
trating it on a single point. Metaphor for meta 
phor, we would rather compare the elementary 
work of attention to that of the telegraph clerk 
who, on receipt of an important despatch, sends 
it back again, word for word, in order to check 
its accuracy. 

But, to send a telegram, we must know how to 
use the machine. And, in the same way, in order to 
reflect upon a perception the image which we have 
received from it, we must be able to reproduce 
it, i.e. to reconstruct it by an effort of synthesis. 


It has been said that attention is a power of 
analysis, and it is true ; but it has not been suffi 
ciently shown how an analysis of this kind is 
possible, nor by what process we are able to 
discover in a perception that which could not be 
perceived in it at first. The truth is that this 
analysis is effected by a series of attempts at a 
synthesis, i.e. by so many hypotheses : our memory 
chooses, one after the other, various analogous 
images which it launches in the direction of the 
new perception. But the choice is not made 
at random. What suggests the hypotheses, 
what presides, even from afar, over the choice 
is the movement of imitation which continues 
the perception, and provides for the perception 
and for the images a common framework. 

But, if this be so, the mechanism of distinct 
perception must be different from what it 
Thus an is usually thought to be. Perception 

attentive -, i 

perception is does not consist merely in impres- 
on r the sions gathered, or even elaborated, by 

present object, , . , TM_- -i 

of chosen the mind. This is the case, at most, 
the* past, with the perceptions that are dissipated 
as soon as received, those which we disperse 
in useful actions. But every attentive percep 
tion truly involves a reflexion, in the etymological 
sense of the word, that is to say the pro 
jection, outside ourselves, of an actively created 
image, identical with, or similar to, the object on 
which it comes to mould itself. If, after having 
gazed at any object, we turn our eyes abruptly 


away, we obtain an after image of it : must 
we not suppose that this image existed already 
while we were looking? The recent discovery 
of centrifugal fibres of perception inclines us to 
think that this is the usual course of things and 
that, beside the afferent process which carries 
the impression to the centre, there is another 
process, of contrary direction, which brings back 
the image to the periphery. It is true that we 
are here dealing with images photographed upon 
the object itself, and with memories following 
immediately upon the perception of which they 
are but the echo. But, behind these images, 
which are identical with the object, there are 
others, stored in memory, which merely resemble 
it, and others, finally, which are only more or 
less distantly akin to it. All these go out to 
meet the perception, and, feeding on its substance, 
acquire sufficient vigour and life to abide with it 
in space. The experiments of Miinsterberg 1 and 
of Kiilpe * leave no doubt as to this latter point : 
any memory-image that is capable of interpreting 
our actual perception inserts itself so thoroughly 
into it that we are no longer able to discern what 
is perception and what is memory. The ingenious 
experiments of Goldscheider and Miiller on the 
mechanism of reading are most interesting in 
this regard. 3 Arguing against Grashey, who, in 

1 Bcitrdge zur experimentetten Psychologic, vol. iv, p. 15 

et seq. 2 Grundriss der Psychologic. Leipzig, 1893, p. 185. 

8 Zur Physiologic und Pathologic dcs Lesens (Zcitschr. /. 


a well-known essay, 1 maintained that we read 
words letter by letter, these observers proved 
by experiments that rapid reading is a real work 
of divination. Our mind notes here and there 
a few characteristic lines and fills all the inter 
vals with memory-images which, projected on 
the paper, take the place of the real printed 
characters and may be mistaken for them. Thus 
we are constantly creating or reconstructing. 
Our distinct perception is really comparable to 
a closed circle in which the perception-image, 
going towards the mind, and the memory- 
image, launched into space, career the one behind 
the other. 

We must emphasize this latter point. Atten 
tive perception is often represented as a series 
The of processes which make their way in 

number and i /- , ,-, i- ... 

complexity single file ; the object exciting sensa- 

tions, the sensations causing ideas to 
on the 1 "" start up before them, each idea setting 
teDJicm in motion, one in front of the other, 

adopted by , r , , 

the mind. points more and more remote of the 
intellectual mass. Thus there is supposed to be 
a rectilinear progress, by which the mind goes 
further and further from the object, never to 
return to it. We maintain, on the contrary. 

Klinische Medicin, 1893). Cf. McKeen Cattell, Ueber dig 
Zeit der Erkennung von Schriftzeichen (Philos. Studien, 1885- 

1 Ueber Aphasie and ihre Beziehungen zur W ahrnehmungen 
(Arch. /. Psychiatric, 1885, vol. xvi). 


that reflective perception is a circuit, in which 
all the elements, including the perceived object 
itself, hold each other in a state of mutual tension 
as in an electric circuit, so that no disturbance 
starting from the object can stop on its way and 
remain in the depths of the mind : it must always 
find its way back to the object whence it proceeds. 
Now, it must not be thought that this is a mere 
matter of words. We have here two radically 
different conceptions of the intellectual process. 
According to the first, things happen mechanic 
ally, and by a merely accidental series of succes 
sive additions. At each moment of an attentive 
perception, for example, new elements sent up 
from a deeper stratum of the mind might join 
the earlier elements, without creating thereby 
a general disturbance and without bringing about 
a transformation of the whole system. In the 
second, on the contrary, an act of attention implies 
such a solidarity between the mind and its object, 
it is a circuit so well closed, that we cannot pass 
to states of higher concentration without creating, 
whole and entire, so many new circuits which 
envelop the first and have nothing in common 
between them but the perceived object. Of 
these different circles of memory, which later 
we shall study in detail, the smallest, A, is the 
nearest to immediate perception. It contains 
only the object O, with the after-image which 
comes back and overlies it. Behind it, the larger 
and larger circles B, C, D correspond to growing 




efforts at intellectual expansion. It is the whole 
of memory, as we shall see, that passes over into 

each of these circuits, since 
memory is always present ; 
but that memory, capable, 
by reason of its elasticity, of 
expanding more and more, 
i reflects upon the object a 
growing number of sug 
gested images, sometimes 
the details of the object 
itself, sometimes concomi 
tant details which may 
throw light upon it. Thus, 
after having rebuilt the 
object perceived, as an 
independent whole, we re 
assemble, together with 
it, the more and more 
distant conditions with which it forms one 
system. If we call B , C , D , these causes of 
growing depth, situated behind the object, and 
virtually given with the object itself, it will 
be seen that the progress of attention results in 
creating anew not only the object perceived, 
but also the ever widening systems with which 
it may be bound up ; so that in the measure in 
which the circles B, C, D represent a higher 
expansion of memory, their reflexion attains 
in B , Of, D deeper strata of reality. 

The same psychical life, therefore, must be 

no. L 


supposed to be repeated an endless number of 
times on the different storeys of memory, and the 
same act of the mind may be performed at 
varying heights. In the effort of attention, the 
mind is always concerned in its entirety, but it 
simplifies or complicates itself according to the 
level on which it chooses to go to work. Usually 
it is the present perception which determines 
the direction of our mind ; but, according to the 
degree of tension which our mind adopts and the 
height at which it takes its stand, the perception 
develops a greater or smaller number of images. 
In other words, personal recollections, exactly 
localized, the series of which represents the course 
so there ate f our P as t existence, make up, all to- 
pies en oi gether, the last and largest enclosure 
the m Seat f our memory. Essentially fugitive, 
SS, 811 they become materialized only by chance, 
plane 8 of* either when an accidentally precise de- 
dream, termination of our bodily attitude 
attracts them, or when the very indetermination 
of that attitude leaves a clear field to the 
caprices of their manifestation. But this outer 
most envelope contracts and repeats itself in 
inner and concentric circles, which in the : r 
narrower range enclose the same recollections 
grown smaller, more and more removed from 
their personal and original form, and more and 
more capable, from their lack of distinguishing 
features, of being applied to the present percep 
tion and of determining it after the manner of a 


species which defines and absorbs the individual. 
There comes a moment when the recollection thus 
brought down is capable of blending so well with 
the present perception that we cannot say where 
perception ends or where memory begins. At 
that precise moment, memory, instead of capri 
ciously sending in and calling back its images, 
follows regularly, in all their details, the move 
ments of the body. 

But, in the degree that these recollections draw 
nearer to movements, and so to external per- 
wwie, on ception, the work of memory acquires 
action" 16 f a m g ner practical importance. Past 
images, reproduced exactly as they were, 

bec^Leone w ^ n a ^ their details and even with their 
with action, affective colouring, are the images of 
idle fancy or of dream : to act is just to induce 
this memory to shrink, or rather to become 
thinned and sharpened, so that it presents nothing 
thicker than the edge of a blade to actual exper 
ience, into which it will thus be able to penetrate. 
In truth, it is because psychology has failed to 
separate out the motor element in memory, that 
we have sometimes overlooked and sometimes 
exaggerated what is automatic in the evocation 
of remembrances. According to our view, an 
appeal is made to activity at the precise moment 
when perception gives rise to imitative move 
ments which scan it, as it were, automatically. A 
sketch is thereby furnished to us, into which we 
put the right details and the right colouring by 


projecting into it memories more or less remote. 
But such is not the usual way of describing the 
process. Sometimes the mind is supposed to be 
absolutely independent of circumstances, to work 
exactly as it likes on present or absent objects ; 
and then we can no longer understand how it is 
that the normal process of attention may be 
seriously impaired by even a slight disturbance 
of the sensori-motor equilibrium. Sometimes, 
on the contrary, the evocation of images is sup 
posed to be a mere mechanical effect of present 
perception ; it is assumed that, by a necessary 
concatenation of processes supposed to be all 
alike, the object calls forth sensations and the 
sensations ideas which cling to them ; but then, 
since there is no reason why the operation, which 
is mechanical to begin with, should change its 
character as it goes on, we are led to the hypo 
thesis of a brain wherein mental states may dwell 
to slumber and to awaken. In both cases the 
true function of the body is misunderstood, and 
as neither theory teaches how and why the inter 
vention of a mechanism is necessary, neither of 
them is able to show where such intervention 
should stop if it is once brought in. 

But it is time to leave these general considera 
tions. We must ascertain whether our hypothesis 
is confirmed or contradicted by the facts of 
cerebral localization known at the present day. 
The disorders of imaginative memory, which 
correspond to local lesions of the cortex, are 


always diseases of the faculty of recognition ; 
either of visual or auditory recognition in general 
(psychic blindness and deafness), or of the recog 
nition of words (word blindness, word deafness, 
etc.). These disorders we have now to exam 

If our hypothesis is well founded, these failures 

of recognition are in no sense due to the fact 

that the recollections occupied the in- 

Hence we may __ r 

infer that jured region of the brain. They must 

lesions oi the J * 

brain affect be due to one of two causes : some- 

the automatic 

movements of times our body is no longer able 

inattentive J 

recognition, automatically to adopt, under the influ- 

or the volun- r t 

tary move- e nce of the external stimulus, the precise 

ments of 

attentive attitude by means of which a choice 


but nothing could be automatically made among 
our memories ; sometimes the mem 
ories are no longer able to find a fulcrum in 
the body, a means of prolonging themselves in 
action. In the first case, the lesion affects the 
mechanisms which continue, in an automati 
cally executed movement, the stimulation re 
ceived : attention can no longer be fixed by the 
object. In the second case, the lesion involves 
those particular cortical centres which prepare 
voluntary movements by lending them the re 
quired sensory antecedent, centres which, rightly 
or wrongly, are termed image-centres : attention 
can no longer be fixed by the subject. But, in 
either case, it is actual movements which are 
hindered or future movements which are no 


longer prepared : there has been no destruction 
of memories. 

Now pathology confirms this forecast. It re- 
reveals to us two absolutely distinct kinds of psychic 
blindness and deafness, and of word blindness and 
deafness. In the first kind, visual and auditory 
memories are still evoked, but they cannot apply 
themselves to the corresponding perceptions. In 
the second, evocation of the memories themselves 
is hindered. Is it true that the lesion involves, 
as we said, the sensori-motor mechanisms of auto 
matic attention in the first case, and the imagina 
tive mechanisms of voluntary attention in the 
second ? In order to verify our hypothesis, we 
must limit demonstration to a definite example. 
No doubt we could show that visual recognition 
of things in general, and of words in particular, 
implies a semi-automatic motor process to begin 
with, and then an active projection of memories 
which engraft themselves on the corresponding atti 
tudes. But we prefer to confine ourselves to impres 
sions of hearing, and more particularly to the hear 
ing of articulate language, because this example 
is the most comprehensive. To hear speech is, 
in fact, first of all to recognize a sound, then 
to discover its sense, and finally to interpret it 
more or less thoroughly : in short, it is to pass 
through all the stages of attention and to exercise 
several higher or lower powers of memory. More 
over, no disorders are more common or better 
studied than those of the auditive memory of 


words. And, lastly, acoustic verbal images are 
not destroyed without a serious lesion of certain 
determined convolutions of the cortex : so that 
we are here provided with an undisputed example 
of localization, in regard to which we can enquire 
whether the brain is really capable of storing up 
memories. We have, then, to show in the audi 
tory recognition of words : first, an automatic 
sensori-motor process ; secondly, an active and, 
so to speak, excentric projection of memory- 

i. I listen to two people speaking in a language 
which is unknown to me. Do I therefore hear 
Evidence from them talk ? The vibrations which 
wha y t d we We reacn m y ear s are the same as those 
String and which strike theirs. Yet I perceive 
^mSor The on ly a confused noise, in which all 
diagram. sounds are alike. I distinguish no 
thing, and could not repeat anything. In this 
same sonorous mass, however, the two interlo 
cutors distinguish consonants, vowels and sylla 
bles which are not at all alike, in short, separate 
words. Between them and me where is the 
difference ? 

The question is, how can the knowledge of a 
language, which is only memory, modify the 
material content of a present perception, and 
cause some listeners actually to hear what 
others, in the same physical conditions, do not 
hear. It is alleged, indeed, that the auditory 


recollections of words, accumulated in memory, 
are called up by the sound-impression and come 
to strengthen its effect. But if the conversa 
tion to which I listen is, for me, only a noise, 
we may suppose the sound increased as much 
as we like : the noise will be none the more 
intelligible for being louder. I grant that the 
memory of a word will be called up by the sound 
of that word : yet it is necessary, for this, that 
the sound of the word should have been heard 
by the ear. How can the sounds perceived speak 
to memory, how can they choose, in the store 
house of auditory images, those which should 
come to rejoin them, unless they have been al 
ready separated, distinguished, in short, per 
ceived, as syllables and as words ? 

This difficulty does not appear to have been 
sufficiently noticed by the theorists of sensory 
aphasia. For in word deafness the patient finds 
himself, in regard to his own language, in the 
same position as we all are when we hear an 
unknown tongue. He has generally preserved 
intact his sense of hearing, but he has no under 
standing of the words spoken to him, and is fre 
quently even unable to distinguish them. The 
explanation generally given of the disease is 
that the auditory recollection of words has 
been destroyed in the cortex, or that a lesion, 
sometimes transcortical, sometimes sub-cortical, 
hinders the auditive memory from evoking the 
idea, or the perception from uniting with the 


memory. But in the latter case, at least, the 
psychological question has still to be answered : 
what is the conscious process which the lesion 
has abolished, and what is the intermediary pro 
cess that we go through in our normal condition 
in order to discern words and syllables which are, 
at first, given to the ear as a continuity of sound ? 

The difficulty would be insuperable if we really 
had only auditory impressions on the one hand, 
and auditory memories on the other. Not so 
however, if auditory impressions organize nascent 
movements, capable of scanning the phrase which 
is heard and of emphasizing its main articulations. 
These automatic movements of internal accom 
paniment, at first undecided or uncoordinated, 
might become more precise by repetition ; they 
would end by sketching a simplified figure in 
which the listener would find, in their main lines 
and principal directions, the very movements of 
the speaker. Thus would unfold itself in con 
sciousness, under the form of nascent muscular 
sensations, the motor diagram, as it were, of the 
speech we hear. To adapt our hearing to a 
new language would then consist, at the outset, 
neither in modifying the crude sound nor in sup 
plementing the sounds with memories ; it would 
be to coordinate the motor tendencies of the mus 
cular apparatus of the voice to the impressions of 
the ear ; it would be to perfect the motor accom 

In learning a physical exercise, we begin by 


imitating the movement as a whole, as our eyes 
see it from without, as we think we have seen it 
done. Our perception of it is confused ; confused 
therefore will be the movement whereby we try to 
repeat it. But whereas our visual perception was 
of a continuous whole, the movement by which we 
endeavour to reconstruct the image is compound 
and made up of a multitude of muscular contrac 
tions and tensions ; and our consciousness of these 
itself includes a number of sensations resulting 
from the varied play of the articulations. The 
confused movement which copies the image is, 
then, already its virtual decomposition ; it bears 
within itself, so to speak, its own analysis. The 
progress which is brought about by repetition and 
practice consists merely in unfolding what was 
previously wrapped up, in bestowing on each of 
the elementary movements that autonomy which 
ensures precision, without, however, breaking up 
that solidarity with the others without which it 
would become useless. We are right when we 
say that habit is formed by the repetition of an 
effort ; but what would be the use of repeating 
it, if the result were always to reproduce the same 
thing ? The true effect of repetition is to decom 
pose, and then to recompose, and thus appeal to 
the intelligence of the body. At each new attempt 
it separates movements which were interpenetrat 
ing; each time it calls the attention of the body 
to a new detail which had passed unperceived ; 
it bids the body discriminate and classify; it 


teaches what is the essential ; it points out, 
one after another, within the total movement, 
the lines that mark off its internal structure. 
In this sense, a movement is learnt when the 
body has been made to understand it. 

So a motor accompaniment of speech may well 
break the continuity of the mass of sound. But we 
But this have now to point out in what this 
Smpanfment accompaniment consists. Is it speech 
peech r !Ldi- itself , repeated internally ? If this were 
Sts slS so * ne child would be able to repeat all 
outlines. the words that its ear can distinguish ; 
and we ourselves should only need to understand 
a foreign language to be able to pronounce it 
with a correct accent. The matter is far from 
being so simple. I may be able to catch a tune, 
to follow its phrasing, even to fix it in memory, 
without being able to sing it. I can easily dis 
tinguish the peculiarities of inflexion and tone in 
an Englishman speaking German I correct him 
therefore, mentally ; but it by no means follows 
that I could give the right inflexion and tone to 
the German phrase, if I were to utter it. Here, 
moreover, the observation of every-day life is 
confirmed by clinical facts. It is still possible to 
follow and understand speech when one has be 
come incapable of speaking. Motor aphasia does 
not involve word deafness. 

This is because the diagram, by means of which 
we divide up the speech we hear, indicates only 
its salient outlines. It is to speech itself what 


the rough sketch is to the finished picture. For it 
is one thing to understand a difficult movement, 
another to be able to carry it out. To under 
stand it, we need only to realize in it what is 
essential, just enough to distinguish it from all 
other possible movements. But to be able to 
carry it out, we must besides have brought our 
body to understand it. Now, the logic of the body 
admits of no tacit implications. It demands 
that all the constituent parts of the required 
movement shall be set forth one by one, and 
then put together again. Here a complete analysis 
is necessary, in which no detail is neglected, 
and an actual synthesis, in which nothing is 
curtailed. The imagined diagram, composed of 
a few nascent muscular sensations, is but a sketch. 
The muscular sensations, really and completely 
experienced, give it colour and life. 

It remains to be considered how an accom 
paniment of this kind can be produced, and 
Evidence whether it really is always produced. 
Ss o?^ We know that in order effectively to 
aphasia, in pronounce a word the tongue and lips 
must articulate, the larynx must be 
brought into play for phonation, and 
affected. fa e muscles of the chest must produce 
an expiratory movement of air. Thus, to every 
syllable uttered there corresponds the play of a 
number of mechanisms already prepared in the 
cerebral and bulbar centres. These mechanisms 
are joined to the higher centres of the cortex by 


the axis-cylinder processes of the pyramidal cells 
in the psycho-motor zone. Along this path the 
impulse of the will travels. So, when we desire 
to articulate this or that sound, we transmit the 
order to act to this or that group of motor me 
chanisms selected from among them all. But, 
while the ready-made mechanisms which corres 
pond to the various possible movements of articu 
lation and phonation are connected with the causes 
(whatever these may be) which set them to work 
in voluntary speech, there are facts which put 
beyond all doubt the linkage of these same mechan 
isms with the auditory perception of words. First 
of all, among the numerous varieties of aphasia de 
scribed in clinical reports, we know of two (Licht- 
heim s 4th and 6th forms) which appear to imply 
a relation of this kind. Thus, in a case observed 
by Lichtheim himself, the subject had lost, as the 
result of a fall, the memory of the articulation 
of words, and consequently the faculty of spon 
taneous speech ; yet he repeated quite correctly 
what was said to him. 1 On the other hand, in 
cases where spontaneous speech is unaffected, 
but where word deafness is absolute and the 
patient no longer understands what is said to 
him, the faculty of repeating another person s words 
may still be completely retained. 8 It may be 
said, with Bastian, that these phenomena merely 
point to a fatigue of the articulatory or auditive 

1 Lichtheim, On Aphasia (Brain, Jan. 1885, p. 447). 

2 Ibid., p. 454. 


memory of words, the acoustic impressions only 
serving to awaken that memory from its torpor. 1 
We may have to allow for this hypothesis, but it 
does not appear to us to account for the curious 
phenomena of echolalia, long since pointed out 
by Romberg, 2 Voisin 8 and Forbes Winslow, 4 
which are termed by Kussmaul 5 (probably with 
some exaggeration) acoustic reflexes. Here the 
subject repeats mechanically, and perhaps uncon 
sciously, the words he hears, as though the auditory 
sensations converted themselves automatically 
into movements of articulation. From these 
facts some have inferred that there is a special 
mechanism which unites a so-called acoustic cen 
tre of words with an articulatory centre of speech. 6 
The truth appears to lie between these two hypo 
theses. There is more in these various phenomena 
than absolutely mechanical actions, but less than 
an appeal to voluntary memory. They testify 
to a tendency of verbal auditory impressions to 

1 Bastian, On Different Kinds of Aphasia (British Medical 
Journal, Oct. and Nov. 1887, p. 935). 

a Romberg, Lehrbuch der Nervenkrankheiten, 1853, vol. ii. 

8 Quoted by Bateman, On Aphasia. London, 1890, p. 79. 
Cf. Marce", Memoire sur quelques observations de physiologic 
pathologique (Mem. de la Soc. de Biologie, 2nd series, vol. ii, 
p. 102). 

4 Forbes Winslow, On Obscure Diseases of the Brain. 
London, 1861, p. 505. 

6 Kussmaul, Die Storungen der Sprache, Leipzig. 1877, PP- 
55 et seq. 

Arnaud, Contribution a V etude clinique de la surdite verbale 
(Arch, de neurologie, 1886, p. 192). Spamer, Ueber Asymbolie 
(Arch. /. Psychiatrie, vol. vi, pp. 507 and 524). 


prolong themselves in movements of articulation ; 
a tendency which assuredly does not escape, as 
a rule, the control of the will, perhaps even im 
plies a rudimentary discrimination, and expresses 
itself, in the normal state, by an internal repe 
tition of the striking features of the words that 
are heard. Now our motor diagram is nothing 

Considering this hypothesis more closely, we 
shall perhaps find in it the psychological explana 
tion, which we were just now seeking, of certain 
forms of word deafness. A few cases of word 
deafness are known where there was a com 
plete survival of acoustic memory. The patient 
had retained, unimpaired, both the auditive 
memory of words and the sense of hearing ; 
yet he recognized no word that was said to 
him. 1 A subcortical lesion is here supposed, 
which prevents the acoustic impressions from 
going to join the verbal auditory images in the 
cortical centres where they are supposed to be 
deposited. But, in the first place, the question 
is whether the brain can store up images. And, 
secondly, even if it were proved that there is 
some lesion in the paths that the acoustic impres 
sions have to follow, we should still be compelled 
to seek a psychological interpretation of the final 

1 See, in particular : P. Serieux, Sur un cos de surdite 
verbale pure (Revue de Medecine, 1893, p. 733 et seq.) ; Licht- 
heim, loc. cit., p. 461 ; and Arnaud, Contrib. d I etude de la 
surdite vcrbtde (2 article), Arch, de Neurologic, 1886, p. 366. 


result. For, by hypothesis, the auditory memories 
can still be recalled to consciousness ; by hypo 
thesis also, the auditory impressions still reach 
consciousness ; there must therefore be in con 
sciousness itself a gap, a solution of continuity, 
something, whatever it is, which hinders the 
perception from joining the memories. Now, we 
may throw some light on the case if we remember 
that crude auditory perception is really that of 
a continuity of sound, and that the sensori-motor 
connexions established by habit must have as 
their office, in the normal state, to decompose this 
continuity. A lesion of these conscious mechan 
isms, by hindering the decomposition, might 
completely check the up-rush of memories which 
tend to alight upon the corresponding perceptions. 
Therefore the motor diagram might be what is 
injured by the lesion. If we pass in review the 
cases (which are, indeed, not very numerous) of 
word deafness where acoustic memories were 
retained, we notice certain details that are inter 
esting in this respect. Adler notes, as a remark 
able fact in word deafness, that the patients no 
longer react even to the loudest sounds, though 
their hearing has preserved all its acuteness. 1 
In other words, sound no longer finds in them its 
motor echo A patient of Charcot s, attacked by 
a passing word deafness, relates that he heard 
his clock strike, but that he could not count the 

1 Adler, Beitrag zur Kenntniss der seltneren Formen von 
nensorischtr Aphasie (Neurol. Centralblatt, 1891, p. 296 et eq.). 


strokes. 1 Probably he was unable to separate 
and distinguish them. Another patient declares 
that he perceives the words of a conversation, 
but as a confused noise. 2 Lastly, the patient 
who has lost the understanding of the spoken 
word recovers it if the word is repeated to him 
several times, and especially if it is pronounced 
with marked divisions, syllable by syllable. 3 
This last fact, observed in several cases of word 
deafness where acoustic memories were unim 
paired, is particularly significant. 

Strieker s 4 mistake was to believe in a complete 
internal repetition of the words that are heard. 
His assertion is already contradicted by the 
simple fact that we do not know of a single 
case of motor aphasia which brought out word 
deafness. But all the facts combine to prove 
the existence of a motor tendency to separate 
the sounds and to establish their diagram. This 
automatic tendency is not without (as we said 
above) a certain elementary mental effort : how 
otherwise could we identify with each other, 
and consequently follow with the same diagram, 

1 Bernard, De I Aphasie. Paris, 1889, p. 143. 

1 Ballet, Le langage interieur. Paris, 1888, p. 85. 

8 See the three cases cited by Arnaud in the Archives de 
neurologic, 1886, p. 366 et seq. (Contrib. clinique a I elude de la 
surdite verbale, 2? article). Cf. Schmidt s case, Gehors- und 
Sprachstdrung in Folgc von Apoplexic (Allg. Zeitschriften /. 
Psychiatric, 1871, vol. xxvii, p. 304). 

4 Strieker, Studien iiber die Sprachvorstellung. Vienna, 1880. 


similar words pronounced on different notes 
and by different qualities of voice ? These 
inner movements of repeating and recognizing 
are like a prelude to voluntary attention. They 
mark the limit between the voluntary and the 
automatic. By them, as we hinted before, the 
characteristic phenomena of intellectual recogni 
tion are first prepared and then determined. 
But what is this complete and fully conscious 
recognition ? 

2. We come to the second part of our subject : 
from movements we pass to memories. We have 
Transition to sa ^ that attentive recognition ie a kind 

?* of ^ circuit, in which the external object 
to us deeper and deeper parts 
itself, as our memory adopts a 
n?- correspondingly higher degree of tension 
cai process. j n or( j er to project recollections towards 
it. In the particular case we are now considering, 
the object is an interlocutor whose ideas develop 
within his consciousness into auditory representa 
tions which are then materialized into uttered 
words. So, if we are right, the hearer places him 
self at once in the midst of the corresponding ideas, 
and then develops them into acoustic memories 
which go out to overlie the crude sounds perceived, 
while fitting themselves into the motor diagram. 
To follow an arithmetical addition is to do it 
over again for ourselves. To understand another s 
words is, in like manner, to reconstruct intelli- 



gently, starting from the ideas, the continuity of 
sound which the ear perceives. And, more gener 
ally, to attend, to recognize intellectually, to 
interpret, may be summed up in a single opera 
tion whereby the mind, having chosen its level, 
having selected within itself, with reference to 
the crude perceptions, the point that is exactly 
symmetrical with their more or less immediate 
cause, allows to flow towards them the memories 
that will go out to overlie them. 

Such, however, is certainly not the usual way 
of looking at the matter. The associationist habit 
is there ; and, in accordance with it, we find men 
maintaining that, by the mere effect of contiguity, 
the perception of a sound brings back the memory 
of the sound and memories bring back the cor 
responding ideas. And then, we have the cerebral 
lesions which seem to bring about a destruction of 
memories ; more particularly, in the case we are 
studying, there are the lesions of the brain found 
in word deafness. Thus psychological observa 
tions and clinical facts seem to conspire. To 
gether they seem to point to the existence, within 
the cortex, of auditory memories slumbering, 
whether as a physico-chemical modification of cer 
tain cells or under some other form. A sensory 
stimulation is then supposed to awaken them ; 
and, finally, by an intra-cerebral process, perhaps 
by trans-cortical movements that go to find the 
complementary representations, they are supposed 
to evoke ideas. 


Now consider lor a moment the amazing con 
sequences of an hypothesis of this kind. The 
auditory image of a word is not an 
object with well-defined outlines; for 
tne same word pronounced by different 
theS 8 woSd voices, or by the same voice on different 
dbwte notes > g ives a different sound. So, if 
Y ou adopt the hypothesis of which we 
have been speaking, you must assume 
that there are as many auditory images 
of the same word as there are pitches of 
sound and qualities of voice. Do you mean that 
all these images are treasured up in the brain ? 
Or is it that the brain chooses ? If the brain 
chooses one of them, whence comes its pre 
ference ? Suppose, even, that you can explain 
why the brain chooses one or the other ; how 
is it that this same word, uttered by a new 
person, gives a sound which, although different, 
is still able to rejoin the same memory ? For 
you must bear in mind that this memory is 
supposed to be an inert and passive thing and 
consequently incapable of discovering, beneath 
external differences, an internal similitude. You 
speak of the auditory image of a word as if it 
were an entity or a genus : such a genus can, 
indeed, be constructed by an active memory 
which extracts the resemblance of several com 
plex sounds and only retains, as it were, their 
common diagram. But, for a brain that is sup 
posed nay, is bound to record only the materi- 


ality of the sounds perceived, there must be, of 
one and the same word, thousands of distinct 
images. Uttered by a new voice, it will constitute a 
new image, which will simply be added to the others. 
But there is something still more perplexing. 
A word has an individuality for us only from the 
moment that we have been taught to abstract 
it. What we first hear are short phrases, not words. 
A word is always continuous with the other 
words which accompany it, and takes different 
aspects according to the cadence and movement 
of the sentence in which it is set : just as each 
note of a melody vaguely reflects the whole musi 
cal phrase. Suppose, then, that there are indeed 
model auditory memories, consisting in certain 
intra-cerebral arrangements, and lying in wait for 
analogous impressions of sound : these impressions 
may come, but they will pass unrecognized. How 
could there be a common measure, how could 
there be a point of contact, between the dry, 
inert, isolated image and the living reality of the 
word organized with the rest of the phrase ? 
I understand clearly enough that beginning of auto 
matic recognition which would consist, as I have 
said above, in emphasizing inwardly the principal 
divisions of the sentence that is heard, and so 
in adopting its movement. But, unless we are to 
suppose in all men identical voices pronouncing 
in the same tone the same stereotyped phrases, 
I fail to see how the words we hear are able to 
rejoin their images in the brain. 


Now, if memories are really deposited in the 

cortical cells, we should find in sensory aphasia, 

The pheno- for instance, the irreparable loss of 

sory aphasia do certain determined words, the integral 

not point to the . . , _^ 
existence of Conservation OI Others. But, as a mat- 
but suggest a ter of fact, things happen quite differ- 
very different , . . . , . . 

hypothesis. entry, bometimes it is the whole set 
of memories that disappears, the faculty of 
mental hearing being purely and simply abol 
ished ; sometimes there is a general weakening of 
the function ; but it is usually the function which 
is diminished and not the number of recollections. 
It seems as if the patient had no longer strength 
to grasp his acoustic memories, as if he turned 
round about the verbal image without being able 
to hit upon it. To enable him to recover a word 
it is often enough to put him on the track of it, 
by giving him its first syllable, 1 or even by merely 
encouraging him. 2 An emotion may produce 
the same effect. 8 There are, however, cases in 
which it does indeed seem that definite groups 
of representations have disappeared from memory. 
I have passed in review a large number of these 
facts, and it has seemed that they could be referred 

1 Bernard, op. tit., pp. 172 and 179. Cf. Babilde, Les troubles 
de la memoire dans I alcoolisme. Paris, 1886 (medical thesis), 

P- 44- 

2 Rieger, Bcschreibung der Intelligenzstorungen in Folge 
einer Hirnverletzung. Wurzburg, 1889, p. 35. 

8 Wernicke, Der aphasische Symptomencomplex. Breslau, 
1874, p. 39. Cf. Valentin, Sur un cas d aphasie d origine 
traumatiqne (Revue medicale de I Est, 1880, p. 171). 


to two absolutely distinct categories. In the 
first, the loss of memories is usually abrupt ; 
in the second, it is progressive. In the first, the 
recollections detached from memory are arbitrarily 
and even capriciously chosen : they may be certain 
words, certain figures, or often all the words 
of an acquired language. In the second, the 
disappearance of the words is governed by a 
methodical and grammatical order, that which is 
indicated by Ribot s law : proper names go first, 
then common nouns, and lastly verbs. 1 Such 
are the external differences. Now this, I believe, 
is the internal difference. In the amnesias of the 
first type, which are nearly always the result of 
a violent shock, I incline to think that the 
memories which are apparently destroyed are 
really present, and not only present but acting. 
To take an example frequently borrowed from 
Forbes Winslow, 2 that of a patient who had 
forgotten the letter F, and the letter F only, 
I wonder how it is possible to subtract a given 
letter wherever met with, to detach it, that 
is, from the spoken or written words in which 
it occurs, if it were not first implicitly re 
cognized. In another case cited by the same 
author, the patient had forgotten languages 

1 Ribot, Les maladies de la memoir e. Paris, 1881, p. 131 
et seq. 

2 Forbes Winslow, On Obscure Diseases of the Brain. London, 

3 Ibid., p. 372 


he had learnt and poems he had written. Hav 
ing begun to write again, he reproduced nearly 
the same lines. Moreover, in such cases the patient 
may often recover the lost memories. Without 
wishing to be too dogmatic on a question of this 
kind, we cannot avoid noticing the analogy be 
tween these phenomena and that dividing of 
the self of which instances have been described 
by Pierre Janet : l some of them bear a remark 
able resemblance to the negative hallucinations/ 
and suggestions with point de replre, induced by 
hypnotizers. 2 Entirely different are the aphasias 
of the second kind, which are indeed the true 
aphasias. These are due, as we shall try to 
show presently, to the progressive diminution 
of a well- localized function, the faculty of actual 
izing the recollection of words. How are we to 
explain the fact that amnesia here follows a 
methodical course, beginning with proper nouns 
and ending with verbs ? We could hardly explain 
it if the verbal images were really deposited in 

1 Pierre Janet, Etat mental des hysteriques. Paris, 1894, 
vol. ii, p. 263 et seq. Cf. UAutomatisme psychologique, by 
the same author, Paris, 1889. 

2 See Grashey s case, studied afresh by Sommer, and by 
him declared to be inexplicable by the existing theories of 
aphasia. In this instance, the movements executed by the 
patient seem to me to have been signals addressed by him 
to an independent memory. (Sommer, Zur Psychologic der 
Sprache, Zeitschr. f. Psychol. u. Physiol. der Sinnesorgane, vol. 
ii, 1891, p. 143 et seq.) Cf. Sommer s paper at the Con 
gress of German Alienists, Arch, de Neurologie, vol. xxiv, 1892). 


the cells of the cortex : it would be wonderful 
indeed that disease should always attack these 
cells in the same order. 1 But the fact can be 
explained, if we admit that memories need, for 
their actualization, a motor ally, and that they 
require for their recall a kind of mental attitude 
which must itself be engrafted upon an attitude 
of the body. If such be the case, verbs in gene 
ral, which essentially express imitable actions, are 
precisely the words that a bodily effort might 
enable us to recapture when the function of 
language has all but escaped us : proper names, 
on the other hand, being of all words the most 
remote from those impersonal actions which our 
body can sketch out, are those which a weaken 
ing of the function will earliest affect. It is a 
noteworthy fact that the aphasic patient, who 
has become as a rule incapable of finding 
the noun he seeks, may replace it by an 
appropriate periphrasis into which other nouns, 2 
and perhaps even the evasive noun itself, 
enter. Unable to think of the precise word, 
he has thought of the corresponding action, and 
this attitude has determined the general direction 
of a movement from which the phrase then 
springs. So likewise it may happen to any of us. 
that, having retained the initial of a forgotten 
name, we recover the name by repeating the 

1 Wundt, Grundzuge der physiologische Psychologic. 
Leipzig, 1903, vol i, 314-315. 

2 Bernard, De Vaphasie. Paris, 1889, pp. 171 and 174. 


initial. 1 Therefore, in facts of the second kind, 
it is the function that is attacked as a whole, 
and in those of the first kind the forgetting, 
though in appearance more complete, is never 
really final. Neither in the one case nor in the 
other do we find memories localized in certain 
cells of the cerebral substance and abolished by 
their destruction. 

But let us question our own consciousness, and 
ask of it what happens when we listen to the words 
whatintro- f another person with the desire to 
to?ayoii 1 the understand them. Do we passively wait 
for the impressions to go in search of 
their images ? Do we not rather feel that we 
are adopting a certain disposition which varies 
with our interlocutor, with the language he 
speaks, with the nature of the ideas which he 
expresses, and varies, above all, with the general 
movement of his phrase, as though we were choos 
ing the key in which our own intellect is called 
upon to play ? The motor diagram, emphasizing 
his utterance, following through all its windings 
the curve of his thought, shows our thought the 
road. It is the empty vessel, which determines, 
by its form, the form which the fluid mass, rush 
ing into it, already tends to take. 

But psychologists may be unwilling to explain 

1 Graves cites the case of a patient who had forgotten all 
names but remembered their initial, and by that means was 
able to recover them (quoted by Bernard, De I aphasie, 
p. 179). 


in this way the mechanism of interpretation, 
current errors because of the invincible tendency which 
Surtare impels us to think on all occasions of 
te u ndency e oi things rather than of movements. We 
to have said that we start from the idea, 
and that we develop it into auditory 
movement, memory-images capable of inserting 
themselves in the motor diagram, so as to over 
lie the sounds we hear. We have here a con 
tinuous movement, by which the nebulosity of 
the idea is condensed into distinct auditory 
images, which, still fluid, will be finally solidified as 
they coalesce with the sounds materially perceived 
At no moment is it possible to say with precision 
that the idea or the memory-image ends, that the 
memory-image or the sensation begins. And, in 
fact, where is the dividing line between the confu 
sion of sounds perceived in the lump and the clear 
ness which the remembered auditory images add to 
them, between the discontinuity of these remem 
bered images themselves and the continuity of 
the original idea which they dissociate and refract 
into distinct words ? But scientific thought, 
analysing this unbroken series of changes, and 
yielding to an irresistible need of symbolic present 
ment, arrests and solidifies into finished things the 
principal phases of this development. It erects 
the crude sounds heard into separate and complete 
words, then the remembered auditory images into 
entities independent of the idea they develop : 
these three terms, crude perception, auditory image 


and idea, are thus made into distinct wholes 
of which each is supposed to be self-sufficing. 
And while, if we really confined ourselves to pure 
experience, the idea is what we should start from 
since it is to the idea that the auditory memories 
owe their connexion and since it is by the memo 
ries that the crude sounds become completed, 
on the contrary, when once we have arbitrarily 
supposed the crude sound to be by itself com 
plete, and arbitrarily also assumed the memories 
to be connected together, we see no harm in re 
versing the real order of the processes, and in 
asserting that we go from the perception to the 
memories and from the memories to the idea. 
Nevertheless, we cannot help feeling that we must 
bring back again, under one form or another, at 
one moment or another, the continuity which we 
have thus broken between the perception, the mem 
ory and the idea. So we make out that these three 
things, each lodged in a certain portion of the cortex 
or of the medulla, intercommunicate, the percep 
tions going to awaken the auditory memories, 
and the memories going to rouse up the ideas. 
As we have begun by solidifying into distinct and 
independent things what were only phases the 
main phases of a continuous development, we 
go on materializing the development itself into 
lines of communication, contacts and impulsions. 
But not with impunity can we thus invert the 
true order, and as a necessary consequence, intro 
duce into each term of the series elements which 


are only realized by those that follow. Not with 
impunity, either, can we congeal into distinct and 
independent things the fluidity of a continuous 
undivided process. This symbolism may indeed 
suffice as long as it is strictly limited to the facts 
which jhave served to invent it : but each new 
fact will force us to complicate our diagram, to in 
sert new stations along the line of the movement ; 
and yet all these stations laid side by side will 
never be able to reconstitute the movement itself. 
Nothing is more instructive, in this regard, than 
the history of the diagrams of sensory apha 
sia. In the early period, marked by 

Illustrations , _. Tr J 

from the the work of Charcot, 1 Broadbent, 2 Kuss- 
theories oi maul 3 and Lichtheim, 4 the theorists 
confined themselves to the hypothesis 
of an ideational centre linked by transcortical 
paths to the various speech centres. But, as 
the analysis of cases was pushed further, this 
centre for ideas receded and finally disap 
peared. For, while the physiology of the brain 
was more and more successful in localizing sensa 
tions and movements, but never ideas, the diversity 
of sensory aphasias obliged clinicians to break up 

1 Bernard, De I aphasie, p. 37. 

2 Broadbent, A Case of Peculiar Affection of Speech (Brain, 
1879, p. 494). 

8 Kussmaul, Die Stdrungen der Sprache. Leipzig, 1877, 
p. 182. 

4 Lichtheim, On Aphasia (Brain, 1885). Yet we must note 
the fact that Wernicke, the first to study sensory aphasia 
methodically, was able to do without a centre for concepts 
(Der aphasische Symptomencotnplex. Breslau, 1874). 


the intellectual centre into a growing multiplicity 
of image centres a centre for visual representa 
tions, for tactile representations, for auditory 
representations, etc., nay, to divide sometimes 
into two different tracks, the one ascending and 
the other descending, the line of communication 
between any two of them. 1 This was the charac 
teristic feature of the diagrams of the later period, 
those of Wysman, 8 of Moeli, 8 of Freud, 4 etc. 
Thus the theory grew more and more compli 
cated, yet without ever being able to grasp the 
full complexity of reality. And as the diagrams 
became more complicated, they figured and sug 
gested the possibility of lesions which, just because 
they were more diverse, were more special and more 
simple, the complication of the diagram being due 
precisely to that dissociation of centres which had 
at first been confounded. Experience, however, 
was far from justifying the theory at this point, 
since it nearly always showed, in partial and diverse 
combinations, several of those simple psychical 

1 Bastian, On Different Kinds of Aphasia (Brit. Med. Journal, 
1887). Cf. the explanation (indicated merely as possible) 
of optical aphasia by Bernheim : De la cecite psychique des 
choses (Revue de Medecine, 1885). 

2 Wysman, Aphasic und verwandte Zustdnde (Deutches 
Archiv. fur Klinische Medecin, 1880). Magnan had already 
opened the way, as Skwortzoff s diagram indicates, De 
la cecite des mots (Th. de Med., 1881, pi. i). 

8 Moeli, Ueber Aphasie bei Wahrnehmung der Gegenstdnde 
durch das Gesicht (Berliner Klinische Wochenschrift, 28 Apr., 

4 Freud, Zur Auffassung der Aphasien. Leipzig, 1891. 


lesions which the theory isolated. The complica 
tion of the theories of aphasia being thus self- 
destructive, it is no wonder that modern patho 
logy, becoming more and more sceptical with 
regard to diagrams, is returning purely and simply 
to the description of facts. 1 

But how could it be otherwise ? To hear some 
theorists discourse on sensory aphasia, we might 
imagine that they had never considered with any 
care the structure of a sentence. They argue as if 
a sentence were composed of nouns which call up 
the images of things. What becomes of those 
parts of speech, of which the precise function is to 
establish, between images, relations and shades of 
meaning of every kind ? Is it said that each of 
such words still expresses and evokes a material 
image, more confused, no doubt, but yet deter 
mined ? Consider then the host of different rela 
tions which can be expressed by the same word, 
according to the place it occupies and the terms 
which it unites. Is it urged that these are the 
refinements of a highly-developed language, but 
that speech is possible with concrete nouns that 
all summon up images of things ? No doubt 
it is, but the more primitive the language you 
speak with me and the poorer in words which 
express relations, the more you are bound to 
allow for my mind s activity, since you compel 
me to find out the relations which you leave 

1 Sommer, Addressing a Congress of Alienists. (Arch, 
de Neurologic, vol. xxiv, 1892). 


unexpressed : which amounts to saying that you 
abandon more and more the hypothesis that 
each verbal image goes up and fetches down its 
corresponding idea. In truth, there is here only 
a question of degree : every language, whether 
elaborated or crude, leaves many more things to 
be understood than it is able to express. Essen 
tially discontinuous, since it proceeds by juxta 
posing words, speech can only indicate by a few 
guide-posts placed here and there the chief 
stages in the movement of thought. That is why 
I can indeed understand your speech if I start 
from a thought analogous to your own, and follow 
its windings by the aid of verbal images which 
are so many sign-posts that show me the way 
from time to time. But I shall never be able 
to understand it if I start from the verbal 
images themselves, because between two conse 
cutive verbal images there is a gulf which no 
amount of concrete representations can ever fill. 
For images can never be anything but things, 
and thought is a movement. 

It is vain, therefore, to treat memory-images 
and ideas as ready-made things, and then assign 
Attempts to to them an abiding place in problemati- 
locaiize images ca j centres. Nor is it of any avail to 

in the brain J 

Scted b n ~ disguise the hypothesis under the cover 
psychological o f a language borrowed from anatomy 

analysis, . J 

and physiology ; it is nothing but the 
association theory of mind ; it has nothing in its 
favour but the constant tendency of discursive 


intellect to cut up all progress into phases and 
afterwards to solidify these phases into things; 
and since it is born a priori from a kind of 
metaphysical prepossession, it has neither the 
advantage of following the movement of con 
sciousness nor that of simplifying the explana 
tion of the facts. 

But we must follow this illusion up to the point 

where it issues in a manifest contradiction. We 

have said that ideas, pure recollections 

And moreover \ 

contradict summoned from the depths of memory, 


develop into memory-images more and 
more capable of inserting themselves into the 
motor diagram. In the degree that these recol 
lections take the form of a more complete, 
more concrete and more conscious represen 
tation, do they tend to confound themselves 
with the perception which attracts them or of 
which they adopt the outline. Therefore there 
is not, there cannot be in the brain a region in 
which memories congeal and accumulate. The 
alleged destruction of memories by an injury to 
the brain is but a break in the continuous pro 
gress by which they actualize themselves. And, 
consequently, if we insist on localizing the auditory 
memory of words, for instance, in a given part of 
the brain, we shall be led by equally cogent reasons 
to distinguish this image-centre from the percep 
tive centre or to confound the two in one. Now 
this is just what experience teaches. 

For notice the strange contradiction to which 


this theory is led by psychological analysis on 
the one hand, by pathological facts on the other. 
On the one hand, it would seem that if percep 
tion, once it has taken place, remains in the brain 
in the state of a stored-up memory, this can 
only be as an acquired disposition of the very 
elements that perception has affected : how, 
at what precise moment, can it go in search of 
others ? This is, indeed, the most natural hypo 
thesis, and Bain 1 and Ribot 2 are content to 
rest upon it. But, on the other hand, there is 
pathology, which tells us that all the recollections 
of a certain kind may have gone while the 
corresponding faculty of perception remains 
unimpaired. Psychic blindness does not hinder 
seeing, any more than psychic deafness hinders 
hearing. More particularly, in regard to the 
loss of the auditory memory of words the 
only one we are now considering there are a 
number of facts which show it to be regularly 
associated with a destructive lesion of the first and 
second left temporo-sphenoidal convolutions, 3 
though not a single case is on record in which this 
lesion was the cause of deafness properly so-called : 

1 The Senses and the Intellect, p. 329. Cf . Spencer, Principles 
of Psychology, vol. i., p. 456. 

2 Ribot, Les maladies de la memoire. Paris, 1881, p. 10. 

8 See an enumeration of the most typical cases in Shaw s 
article, The Sensory Side of Aphasia (Brain, 1893, p. 501). 
Several authors, however, limit to the first convolution the 
lesion corresponding to the loss of verbal auditory images. 
See, in particular, Ballet, Le langage interieur, p. 153. 


it has even been produced experimentally in the 
monkey without determining anything but psychic 
deafness, that is to say, a loss of the power to 
interpret the sounds which it was still able to 
hear. 1 So that we must attribute to perception 
and to memory separate nervous elements. But 
then this hypothesis will be contradicted by the 
most elementary psychological observation ; for 
we see that a memory, as it becomes more dis 
tinct and more intense, tends to become a percep 
tion, though there is no precise moment at which 
a radical transformation takes place, nor conse 
quently a moment when we can say that it moves 
forward from imaginative elements to sensory ele 
ments. Thus these two contrary hypotheses, the 
first identifying the elements of perception with 
the elements of memory, the second distinguish 
ing them, are of such a nature that each sends 
us back to the other without allowing us to 
rest in either. 

How should it be otherwise ? Here again 
distinct perception and memory-image are taken 
The memory- in the static condition, as things of 

image passes, , . .. . ., . , , , , 

by a dynamic which the first is supposed to be al- 
the K percept1on ready complete without the second ; 
Smes 1C actuai. whereas we ought to consider the dyna 
mic progress by which the one passes into the 

For, on the one hand, complete perception is 

1 Luciani, quoted by J. Soury, Les fonctions du cerveau, 
Paris, 1892, p. 211. 


only defined and distinguished by its coalescence 
with a memory-image, which we send forth to meet 
it. Only thus is attention secured, and without 
attention there is but a passive juxtapositing of 
sensations, accompanied by a mechanical reaction. 
But, on the other hand, as we shall show later, the 
memory-image itself, if it remained pure memory, 
would be ineffectual. Virtual, this memory can 
only become actual by means of the perception 
which attracts it. Powerless, it borrows life and 
strength from the present sensation in which it 
is materialized. Does not this amount to saying 
that distinct perception is brought about by two 
opposite currents, of which the one, centripetal, 
comes from the external object, and the other, 
centrifugal, has for its point of departure that 
which we term pure memory ? The first 
current, alone, would only give a passive percep 
tion with the mechanical reactions which accom 
pany it. The second, left to itself, tends to give 
a recollection that is actualized more and more 
actual as the current becomes more marked. 
Together, these two currents make up, at their 
point of confluence, the perception that is distinct 
and recognized. 

This is the witness of introspection. But 
we have no right to stop there. Undoubtedly 
there is considerable risk in venturing, without 
sufficient evidence, into the obscure problems 
of cerebral localization. But we have said that 
to separate from one another the completed per- 


ception and the memory image is to bring clini 
cal observation into conflict with psychological 
analysis, and that the result is a serious antino 
my in the theory of the localization of memories. 
We are bound to consider what becomes of the 
known facts when we cease to regard the brain 
as a storehouse of memories. 1 

Let us admit, for the moment, in order to simpli- 

1 The theory which is here sketched out resembles, 
in one respect, that of Wundt. We will give the common 
element and the essential difference between them. With 
Wundt, we believe that distinct perception implies a centri 
fugal action ; and thereby we are led to suppose with him 
(although in a slightly different sense), that the so-called 
image centres are rather centres for the grouping of 
sense-impressions. But whereas, according to Wundt, the 
centrifugal action lies in an apperceptive stimulation, the 
nature of which can only be defined in a general manner, 
and which appears to correspond to what is commonly called 
the fixing of the attention, we maintain that this centrifugal 
action bears in each case a distinct form, the very form of 
that virtual object which tends to actualize itself by 
successive stages. Hence an important difference in our 
understanding of the office of the centres. Wundt is led to 
assume : ist, a general organ of apperception, occupying 
the frontal lobe ; 2ndly, particular centres which, though 
most likely incapable of storing images, retain nevertheless 
a tendency or a disposition to reproduce them. Our con 
tention, on the contrary, is that no trace of an image can 
remain in the substance of the brain, and that no such centre 
of apperception can exist ; but that there are merely, in that 
substance, organs of virtual perception, influenced by the 
intention of the memory, as there are at the periphery organs 
of real perception, influenced by the action of the object. (See 
Grundziige der physiologische Psychologic, vol. i, pp. 320-327.) 


fy the argument, that stimuli from without give 
u any image- birth, either in the cortex or in other 

centre really , , , 

exists, it is cerebral centres, to elementary sensa- 
kind oj key- tions. In fact, every perception includes 

board, played . , , , , e , . . 

upon by mem- a considerable number of such sensations, 

ories, as the ,, ... , , . -, . 

sense-organ is all co-existing and arranged in a deter- 
by obje3s! n mined order. Whence comes this order, 
and what ensures this co-existence ? In the case 
of a present material object, there is no doubt as to 
the answer : order and co-existence come from 
an organ of sense, receiving the impression of an 
external object. This organ is constructed pre 
cisely with a view to allowing a plurality of simul 
taneous excitants to impress it in a certain order 
and in a certain way, by distributing themselves, 
all at one time, over selected portions of its sur 
face. It is like an immense keyboard, on which 
the external object executes at once its harmony of 
a thousand notes, thus calling forth in a definite 
order, and at a single moment, a great multitude 
of elementary sensations corresponding to all the 
points of the sensory centre that are concerned. 
Now, suppress the external object or the organ of 
sense, or both : the same elementary sensations may 
be excited, for the same strings are there, ready 
to vibrate in the same way ; but where is the 
keyboard which permits thousands of them to be 
struck at once, and so many single notes to 
unite in one accord ? In our opinion the region 
of images, if it exists, can only be a keyboard 
of this nature. Certainly it is in no way incon- 


ceivable that a purely psychical cause should 
directly set in action all the strings concerned. 
But in the case of mental hearing which alone 
we are considering now the localization of the 
function appears certain, since a definite injury of 
the temporal lobe abolishes it ; and, on the other 
hand, we have set forth the reasons which make 
it impossible for us to admit, or even to conceive, 
traces of images deposited in any region of the 
cerebral substance. Hence only one plausible hy 
pothesis remains, namely, that this region occupies 
with regard to the centre of hearing itself the 
place that is exactly symmetrical with the organ 
of sense. It is, in this case, a mental ear. 

But then the contradiction we have spoken of 
disappears. We see, on the one hand, that the 
auditory image called back by memory must set 
in motion the same nervous elements as the first 
perception, and that recollection must thus change 
gradually into perception. And we see also, on 
the other hand, that the faculty of recalling 
to memory complex sounds, such as words, 
may concern other parts of the nervous sub 
stance than does the faculty of perceiving them. 
This is why in psychic deafness real hearing 
survives mental hearing. The strings are still 
there, and to the influence of external sounds 
they vibrate still; it is the internal keyboard 
which is lacking. 

In other terms, the centres in which the ele 
mentary sensations seem to originate may be actu- 


ated, in some sort, from two different sides, from 
in front and from behind. From the front they 
receive impressions sent in by the sense-organs, 
and consequently by a real object ; from behind 
they are subject, through successive intermedi 
aries, to the influence of a virtual object. The 
centres of images, if these exist, can only be the 
organs that are exactly symmetrical with the 
organs of the senses in reference to the sensory 
centres. They are no more the depositories of 
pure memories, that is, of virtual objects, than 
the organs of the senses are depositories of real 

We would add that this is but a much abridged 
version of what may happen in reality. The 
various sensory aphasias are sufficient proof that 
the calling up of an auditory image is not a 
single act. Between the intention, which is what 
we call the pure memory, and the auditory 
memory-image properly so called, intermediate 
memories are commonly intercalated which must 
first have been realized as memory-images in more 
or less distant centres. It is, then, by successive 
degrees that the idea comes to embody itself in 
that particular image which is the verbal image. 
Thereby mental hearing may depend upon the 
integrity of the various centres and of the paths 
which lead to them. But these complications 
change nothing at the root of things. Whatever 
be the number and the nature of the interven 
ing processes, we do not go from the perception 


to the idea, but from the idea to the perception ; 
and the essential process of recognition is not 
centripetal, but centrifugal. 

Here, indeed, the question arises how stimulation 
from within can give birth to sensations, either 
by its action on the cerebral cortex or on other 
centres. But it is clear enough that we have here 
only a convenient way of expressing ourselves. 
Pure memories, as they become actual, tend to 
bring about, within the body, all the corresponding 
sensations. But these virtual sensations them 
selves, in order to become real, must tend to 
urge the body to action, and to impress upon 
it those movements and attitudes of which they 
are the habitual antecedent. The modifications 
in the centres called sensory, modifications 
which usually precede movements accomplished 
or sketched out by the body and of which the 
normal office is to prepare them while they begin 
them, are, then, less the real cause of the sensa 
tion than the mark of its power and the con 
dition of its efficacy. The progress by which the 
virtual image realizes itself is nothing else than 
the series of stages by which this image gradually 
obtains from the body useful actions or use 
ful attitudes. The stimulation of the so-called 
sensory centres is the last of these stages : it is 
the prelude to a motor reaction, the beginning of 
an action in space. In other words, the virtual 
image evolves towards the virtual sensation, and 
the virtual sensation towards real movement : this 


movement, in realizing itself, realizes both the 
sensation of which it might have been the natural 
continuation, and the image which has tried to 
embody itself in the sensation. We must now 
consider these virtual states more carefully, and, 
penetrating further into the internal mechanism of 
psychical and psycho-physical actions, show by 
what continuous progress the past tends to recon 
quer, by actualizing itself, the influence it had 



To sum up briefly the preceding chapters. We 
have distinguished three processes, pure memory, 
memory-image, and perception, of which no one, 
in fact, occurs apart from the others. Perception 
is never a mere contact of the mind with the 

object present ; it is 
impregnated with 

Pure memory Memorj image Perception which Complete it aS 

A"" ~~B 6 c~ ~~2 they interpret it. The 

I memory-image, in its 

turn, partakes of the 

pure memory, 

FIG. 2. * 

which it begins to 

materialize, and of the perception in which it tends 
to embody itself : regarded from the latter point of 
view, it might be denned as a nascent perception. 
Lastly, pure memory, though independent in 
theory, manifests itself as a rule only in the 
coloured and living image which reveals it. Sym 
bolizing these three terms by the consecutive 
segments AB, BC, CD, of the same straight line 



AD, we may say that our thought describes this 
line in a single movement which goes from A to 
D, and that it is impossible to say precisely where 
one of the terms ends and another begins. 

In fact, this is just what consciousness bears 
witness to whenever, in order to analyse memory, 
it follows the movement of memory at work. 
Whenever we are trying to recover a recollection, 
to call up some period of our history, we become 
conscious of an act sui generis by which we detach 
ourselves from the present in order to replace 
ourselves, first in the past in general, then in a 
certain ^region of the past a work of adjustment, 
something like the focussing of a camera. But 
our recollection still remains virtual ; we simply 
prepare ourselves to receive it by adopting the 
appropriate attitude. Little by little it comes into 
view like a condensing cloud ; from the virtual 
state it passes into the actual ; and as its outlines 
become more distinct and its surface takes on 
colour, it tends to imitate perception. But it re 
mains attached to the past by its deepest roots, 
and if, when once realized, it did not retain 
something of its original virtuality, if, being a 
present state, it were not also something which 
stands out distinct from the present, we should 
never know it for a memory. 

The capital error of associationism is that it 
substitutes for this continuity of becoming, which 
is the living reality, a discontinuous multiplicity 
of elements, inert and juxtaposed. Just because 


each of the elements so constituted contains, by 
Association- reason of its origin, something of what 
ISfutS?" precedes and also of what follows, it must 
ffsifty 11 * 1 take to our eyes the form of a mixed 
Sid moving and, so to speak, impure state. But 
makes oT^ the principle of associationism requires 

that each psychical state should be a 

perception. kind Qf ^^ & gimple dement Hence 

the necessity for sacrificing, in each of the phases 
we have distinguished, the unstable to the stable, 
that is to say, the beginning to the end. If we 
are dealing with perception, we are asked to see in 
it nothing but the agglomerated sensations which 
colour it, and to overlook the remembered images 
which form its dim nucleus. If it is the remem 
bered image that we are considering, we are bidden 
to take it already made, realized in a weak per 
ception, and to shut our eyes to the pure memory 
which this image has progressively developed. In 
the rivalry which associationism thus sets up 
between the stable and the unstable, perception 
is bound to expel the memory-image, and the 
memory-image to expel pure memory. And thus 
the pure memory disappears altogether. Associa 
tionism, cutting in two by a line MO the totality 
of the progress AD, sees, in the part OD, only the 
sensations which terminate it and which have been 
supposed to constitute the whole of perception ;- 
and, on the other hand, it reduces.also the part AO 
to the realized image which pure memory attains 
to as it expands. Psychical life, then, is en- 


tirely summed up in these two elements, sensation 
and image. And as, on the one hand, this 
theory drowns in the image the pure memory 
which makes the image into an original state, 
and, on the other hand, brings the image yet 
closer to perception by putting into perception, 
in advance, something of the image itself, it ends 
by finding between these two states only a differ 
ence of degree, or of intensity. Hence the dis 
tinction between strong states and weak states, of 
which the first are supposed to be set up by us 
as perceptions of the present, and the second (why, 
no man knows) as representations of the past. 
But the truth is that we shall never reach the 
past unless we frankly place ourselves within it. 
Essentially virtual, it cannot be known as some 
thing past unless we follow and adopt the move 
ment by which it expands into a present image, 
thus emerging from obscurity into the light of day. 
In vain do we seek its trace in anything actual 
and already realized : we might as well look for 
darkness beneath the light. This is, in fact, the 
error of associationism : placed in the actual, it 
exhausts itself in vain attempts to discover in a 
realized and present state the mark of its past 
origin, to distinguish memory from perception, 
and to erect into a difference in kind that which 
it condemned in advance to be but a difference 
of magnitude. 

To picture is not to remember. No doubt a 
recollection, as it becomes actual, tends to live in 


an image ; but the converse is not true, and the 
image, pure and simple, will not be referred to the 
past unless, indeed, it was in the past that I sought 
it, thus following the continuous progress which 
brought it from darkness into light. This is what 
psychologists too often forget when they conclude, 
from the fact that a remembered sensation be 
comes more actual the more we dwell upon it, 
that the memory of the sensation is the sensation 
itself beginning to be. The fact which they allege 
is undoubtedly true : the more I strive to recall a 
past pain, the nearer I come to feeling it in reality. 
But this is easy to understand, since the progress 
of a memory precisely consists, as we have said, 
in its becoming materialized. The question is: 
was the memory of a pain, when it began, really 
pain? Because the hypnotized subject ends by 
feeling hot when he is repeatedly told that he is 
hot, it does not follow that the words of the sug 
gestion were themselves hot. Neither must we 
conclude that, because the memory of a sensa 
tion prolongs itself into that very sensation, the 
memory was a nascent sensation : perhaps indeed 
this memory plays, with regard to the sensation 
which follows it, precisely the part of the hypnotizer 
who makes the suggestion. The argument we are 
criticizing, presented in this form, is then already of 
no value as proof ; but still, it is not yet a vicious 
argument, because it profits by the incontestable 
truth that memory passes into something else by 
becoming actual. The absurdity becomes patent 


when the argument is inverted (although this 
ought to be legitimate on the hypothesis adopted), 
that is to say, when the intensity of the sensation is 
decreased instead of the intensity of pure memory 
being increased. For then, if the two states 
differ merely in degree, there should be a given 
moment at which the sensation changed into a 
memory. If the memory of an acute pain, for 
instance, is but a slight pain, inversely an intense 
pain which I feel will end, as it grows less, by being 
an acute pain remembered. Now the moment 
will come, undoubtedly, when it is impossible 
for me to say whether what I feel is a slight sen 
sation which I experience or a slight sensation 
which I imagine (and this is natural, because the 
memory-image is already partly sensation); but 
never will this weak state appear to me to be 
the memory of a strong state. Memory, then, is 
something quite different. 

But the illusion which consists in establishing 
only a difference of degree between memory and 
perception is more than a mere consequence of 
associationism, more than an accident in the 
history of philosophy. Its roots lie deep. It 
rests, in the last analysis, on a false idea of the 
nature and of the object of external perception. 
We are bent on regarding perception as only an 
instruction addressed to a pure spirit, as having 
a purely speculative interest. Then, as memory 
is itself essentially a knowledge of this kind, since its 
object is no longer present, we can only find between 


perception and memory a difference of degree 
perceptions being then supposed to throw mem- 
Bnt memory OI "i es back into the past, and thus to 
reserve to themselves the present simply 
because right is might. But there is 
presenus sen- mucn rnore between past and present 
aSd Eerefore t ^ ian a mere difference of degree. My 
active. present is that which interests me, which 
lives for me, and, in a word, that which summons 
me to action ; whereas my past is essentially power 
less. We must dwell further on this point. By 
contrasting it with present perception we shall 
better understand the nature of what we call 
pure memory/ 

For we should endeavour in vain to characterize 
the memory of a past state unless we began by 
denning the concrete note, accepted by conscious 
ness, of present reality. What is, for me, the 
present moment ? The essence of time is that 
it goes by ; time already gone by is the past, and 
we call the present the instant in which it goes 
by. But there can be no question here of a 
mathematical instant. No doubt there is an 
ideal present a pure conception, the indivisible 
limit which separates past from future. But the 
real, concrete, live present that of which I speak 
when I speak of my present perception that 
present necessarily occupies a duration. Where 
then is this duration placed ? Is it on the hither 
or on the further side of the mathematical point 
which I determine ideally when I think of the 


present instant ? Quite evidently, it is both on 
this side and on that ; and what I call my pre 
sent has one foot in my past and another in my 
future. In my past, first, because the moment 
in which I am speaking is already far from me ; 
in my future, next, because this moment is im 
pending over the future : it is to the future that I 
am tending, and could I fix this indivisible present, 
this infinitesimal element of the curve of time, 
it is the direction of the future that it would in 
dicate. The psychical state, then, that I call 
my present/ must be both a perception of the 
immediate past and a determination of the im 
mediate future. Now the immediate past, in so 
far as it is perceived, is, as we shall see, sensation, 
since every sensation translates a very long suc 
cession of elementary vibrations ; and the im 
mediate future, in so far as it is being determined, 
is action or movement. My present, then, is both 
sensation and movement ; and, since my present 
forms an undivided whole, then the movement 
must be linked with the sensation, must prolong 
it in action. Whence I conclude that my present 
consists in a joint system of sensations and 
movements. My present is, in its essence, sensori- 
our present This is to sa Y that m Y present con- 

materiality o! S ^ S m * ne COnSClOUSneSS that I have 

i ? s U unique ** ^ mv body . Having extension in space, 
moment o! m y body experiences sensations and at 
duration. fa G same time executes movements. 



Sensations and movements being localized at de 
termined points of this extended body, there can 
only be, at a given moment, a single system of 
movements and sensations. That is why my pre 
sent appears to me to be a thing absolutely deter 
mined, and contrasting with my past. Situated 
between the matter which influences it and that 
on which it has influence, my body is a centre of 
action, the place where the impressions received 
choose intelligently the path they will follow to 
transform themselves into movements accom 
plished. Thus it indeed represents the actual 
state of my becoming, that part of my duration 
which is in process of growth. More generally, in 
that continuity of becoming which is reality itself , 
the present moment is constituted by the quasi- 
instantaneous section effected by our perception 
in the flowing mass ; and this section is precisely 
that which we call the material world. Our body 
occupies its centre ; it is, in this material world, 
that part of which we directly feel the flux ; in 
its actual state the actuality of our present lies. 
If matter, so far as extended in space, is to be de 
fined (as we believe it must) as a present which is 
always beginning again, inversely, our present is 
the very materiality of our existence, that is to say, 
a system of sensations and movements, and nothing 
else. And this system is determined, unique for 
each moment of duration, just because sensa 
tions and movements occupy space, and because 
there cannot be in the same place several things 


at the same time. Whence comes it that it has 
been possible to misunderstand so simple, so 
evident a truth, one which is, moreover, the 
very idea of common sense ? 

The reason lies simply in the fact that philoso 
phers insist on regarding the difference between 
But pure actual sensations and pure memory as a 

memory, in ,. . , , . , . , 

which each mere difference in degree, and not in kind. 

unique mo- T , ,.-, . ,. . 

ment of the In our view the difference is radical. 

past survives, _ . . , ~ . 

is essentially My actual sensations occupy definite por- 

detached * , , rj , 

from me. tions of the surface of my body ; pure 
memory, on the other hand, interests no part of 
my body. No doubt, it will beget sensations as it 
materializes ; but at that very moment it will cease 
to be a memory and pass into the state of a present 
thing, something actually lived ; and I shall only 
restore to it its character of memory by carrying 
myself back to the process by which I called it up, 
as it was virtual, from the depths of my past. 
It is just because I made it active that it has 
become actual, that is to say, a sensation capable 
of provoking movements. But most psychologists 
see in pure memory only a weakened perception, 
an assembly of nascent sensations. Having thus 
effaced, to begin with, all difference in kind be 
tween sensation and memory, they are led by the 
logic of their hypothesis to materialize memory 
and to idealize sensation. They perceive memory 
only in the form of an image ; that is to say, already 
embodied in nascent sensations. Having thus 
attributed to it that which is essential to sensa- 


tion, and refusing to see in the ideality of memory 
something distinct, something contrasted with 
sensation itself, they are forced, when they come 
back to pure sensation, to leave to it that ideality 
with which they have thus implicitly endowed nas 
cent sensations. For if the past, which by hypo 
thesis is no longer active, can subsist in the form of 
a weak sensation, there must be sensations that 
are powerless. If pure memory, which by hypo 
thesis interests no definite part of the body, is a 
nascent sensation, then sensation is not essentially 
localized in any point of the body. Hence the 
illusion that consists in regarding sensation as an 
ethereal and unextended state which acquires 
extension and consolidates in the body by mere 
accident : an illusion which vitiates profoundly, 
as we have seen, the theory of external perception, 
and raises a great number of the questions at issue 
between the various metaphysics of matter. We 
must make up our minds to it : sensation is, in 
its essence, extended and localized ; it is a source 
of movement ; pure memory, being inextensive 
and powerless, does not in any degree share the 
nature of sensation. 

That which I call my present is my attitude 

with regard to the immediate future ; it is my 

impending action. My present is, then, 

when actua- sensori-motor. Of my past, that alone 

lized in an . , 

image, becomes image and consequently sensa- 

borrows some- . i i_ n 

thing from tion, at least nascent, which can colla 
borate in that action, insert itself in 


that attitude, in a word make itself useful ; but, 
from the moment that it becomes image, the 
past leaves the state of pure memory and coin 
cides with a certain part of my present. Memory 
actualized in an image differs, then, profoundly 
from pure memory. The image is a present state, 
and its sole share in the past is the memory whence 
it arose. Memory, on the contrary, powerless as 
long as it remains without utility, is pure from 
all admixture of sensation, is without attachment 
to the present, and is consequently unextended. 
This radical powerlessness of pure memory is 
just what will enable us to understand how it is 
preserved in a latent state. Without 

Consciousness x . 

is the note of as vet going to the heart of the matter, 

the present; J & & 

therefore pure we will confine ourselves to the remark 

memory is 

latent and that our unwillingness to conceive un- 

unconscious. . 7 T i i 

conscious psychical states is due, above 
all, to the fact that we hold consciousness to 
be the essential property of psychical states : 
so that a psychical state cannot, it seems, cease 
to be conscious without ceasing to exist. But 
if consciousness is but the characteristic note of 
the present, that is to say of the actually lived, 
in short of the active, then that which does not 
act may cease to belong to consciousness without 
therefore ceasing to exist in some manner. In 
other words, in the psychological domain, con 
sciousness may not be the synonym of existence, 
but only of real action or of immediate efficacy ; 
and, limiting thus the meaning of the term, we 


shall have less difficulty in representing to our 
selves a psychical state which is unconscious, that 
is to say, ineffective. Whatever idea we may frame 
of consciousness in itself, such as it would be if it 
could work untrammelled, we cannot deny that, 
in a being which has bodily functions, the chief 
office of consciousness is to preside over action 
and to enlighten choice. Therefore it throws 
light on the immediate antecedents of the decision, 
and on those past recollections which can usefully 
combine with it ; all else remains in shadow. 
But we find here once more, in a new form, the 
ever-recurrent illusion which, throughout this work, 
we have endeavoured to dispel. It is supposed 
that consciousness, even when linked with bodily 
functions, is a faculty that is only accidentally 
practical, and is directed essentially towards 
speculation. Then, since we cannot see what 
interest, devoted as it is supposed to be to pure 
knowledge, it would have in allowing any infor 
mation that it possesses to escape, we fail to under 
stand why it refuses to throw light on something 
that was not entirely lost to it. Whence we con 
clude that it can possess nothing more de jure 
than what it holds de facto, and that, in the 
domain of consciousness, all that is real is actual. 
But restore to consciousness its true role : there 
will no longer be any more reason to say that 
the past effaces itself as soon as perceived, than 
there is to suppose that material objects cease to 
exist when we cease to perceive them. 


We must insist on this last point, for here we 

have the central difficulty, and the source of the 

ambiguities which surround the problem 

Of uncon- P , T>I J f 

scions mental of the unconscious. The idea of an un- 

statesingen- . . . -, -. , 

erai. Artifl- conscious representation is clear, despite 

cial difficulty -, 

raised round current prejudice; we may even say 
the uncon that we make constant use of it, and 
that there is no conception more familiar 
to common sense. For every one admits that the 
images actually present to our perception are not 
the whole of matter. But, on the other hand, 
what can be a non-perceived material object, an 
image not imagined, unless it is a kind of uncon 
scious mental state ? Beyond the walls of your 
room, which you perceive at this moment, there 
are the adjoining rooms, then the rest of the 
house, finally the street and the town in which 
you live. It signifies little to which theory of 
matter you adhere ; realist or idealist, you are 
evidently thinking, when you speak of the town, 
of the street, of the other rooms in the house, of 
so many perceptions absent from your conscious 
ness and yet given outside of it. They are not 
created as your consciousness receives them ; they 
existed, then, in some sort ; and since, by hypothe 
sis, your consciousness did not apprehend them, 
how could they exist in themselves unless in the 
unconscious state ? How comes it then that an 
existence outside of consciousness appears clear to 
us in the case of objects, but obscure when we 
are speaking of the subject ? Our perceptions, 


actual and virtual, extend along two lines, the 
one horizontal, AB, which contains all simultane 
ous objects in space, the other vertical, CI, on 
which are ranged our successive recollections 
set out in time. The point I, at the intersection 

of the two lines, is 
the only one actually 
given to consciousness. 
Whence comes it that 
we do not hesitate to 

FJG 3> posit the reality of the 

whole line AB, although 

it remains unperceived, while, on the contrary, 
of the line CI, the present I which is actually 
perceived is the only point which appears to 
us really to exist ? There are, at the bottom of 
this radical distinction between the two series, 
temporal and spatial, so many confused or half- 
formed ideas, so many hypotheses devoid of any 
speculative value, that we cannot all at once make 
an exhaustive analysis of them. In order to 
unmask the illusion entirely, we should have to 
seek at its origin, and follow through all its wind 
ings, the double movement by which we come to 
assume objective realities without relation to 
consciousness, and states of consciousness without 
objective reality, space thus appearing to pre 
serve indefinitely the things which are there 
juxtaposed, while time in its advance devours the 
states which succeed each other within it. Part 
of this work has been done in our first chapter, 


where we discussed objectivity in general ; another 
part will be dealt with in the last pages of this 
book, where we shall speak of the idea of matter. 
We confine ourselves here to a few essential points. 

First, the objects ranged along the line AB 
represent to our eyes what we are going to per 
ceive, while the line CI contains only that which 
has already been perceived. Now the past has 
no longer any interest for us ; it has exhausted 
its possible action, or will only recover an influence 
by borrowing the vitality of the present percep 
tion. The immediate future, on the contrary, 
consists in an impending action, in an energy 
not yet spent. The unperceived part of the ma 
terial universe, big with promises and threats, 
has then for us a reality which the actually un 
perceived periods of our past existence cannot 
and should not possess. But this distinction, 
which is entirely relative to practical utility and 
to the material needs of life, takes in our minds 
the more and more marked form of a metaphysical 

We have shown that the objects which sur 
round us represent, in varying degrees, an action 
why the idea which we can accomplish upon things, 

of an existence i -i 

that is real or which we must experience from them, 
perceived ap- The date of fulfilment of this possible 

pears to be . .... , . .. 

clear in the action is indicated by the greater or 

case of an on- . , , ,. , 

perceived less remoteness of the corresponding ob- 

object, obscure . .. . 

in the case of ject, so that distance in space mea- 

an unper- . . , , 

idea, sures the proximity of a threat or of 


a promise in time. Thus space furnishes us at 
once with the diagram of our near future, and, as 
this future must recede indefinitely, space which 
symbolizes it has for its property to remain, in its 
immobility, indefinitely open. Hence the imme 
diate horizon given to our perception appears to 
us to be necessarily surrounded by a wider circle, 
existing though unperceived, this circle itself 
implying yet another outside it and so on, ad 
infinitum. It is, then, of the essence of our actual 
perception, inasmuch as it is extended, to be 
always only a content in relation to a vaster, even 
an unlimited, experience which contains it ; and 
this experience, absent from our consciousness, 
since it spreads beyond the perceived horizon, 
nevertheless appears to be actually given. But 
while we feel ourselves to be dependent upon these 
material objects which we thus erect into present 
realities, our memories, on the contrary, inas 
much as they are past, are so much dead weight 
that we carry with us, and by which we prefer 
to imagine ourselves unencumbered. The same 
instinct, in virtue of which we open out space 
indefinitely before us, prompts us to shut off 
time behind us as it flows. And while reality, 
in so far as it is extended, appears to us to over 
pass infinitely the bounds of our perception, in 
our inner life that alone seems to us to be real 
which begins with the present moment ; the rest 
is practically abolished. Then, when a memory 
reappears in consciousness, it produces on us the 


effect of a ghost whose mysterious apparition 
must be explained by special causes. In truth, 
the adherence of this memory to our present 
condition is exactly comparable to the adherence 
of unperceived objects to those objects which we 
perceive ; and the unconscious plays in each case 
a similar part. 

But we have great difficulty in representing 
the matter to ourselves in this way, because we 
have fallen into the habit of emphasizing the 
differences and, on the contrary, of slurring over 
the resemblances, between the series of objects 
simultaneously set out in space and that of 
states successively developed in time. In the first, 
the terms condition each other in a manner 
which is entirely determined, so that the appear 
ance of each new term may be foreseen. Thus 
I know, when I leave my room, what other 
rooms I shall go through. On the contrary, my 
memories present themselves in an order which 
is apparently capricious. The order of the repre 
sentations is then necessary in the one case, 
contingent in the other ; and it is this necessity 
which I hypostatize, as it were, when I speak 
of the existence of objects outside of all conscious 
ness. If I see no inconvenience in supposing 
given the totality of objects which I do not per 
ceive, it is because the strictly determined order 
of these objects lends to them the appearance of a 
chain, of which my present perception is only 
one link. This link communicates its actuality 


to the rest of the chain. But, if we look at the 
matter nearly, we shall see that our memories 
form a chain of the same kind, and that our char 
acter, always present in all our decisions, is indeed 
the actual synthesis of all our past states. In 
this epitomized form our previous psychical life 
exists for us even more than the external world, 
of which we never perceive more than a very small 
part, whereas on the contrary we use the whole 
of our lived experience. It is true that we possess 
merely a digest of it, and that our former percep 
tions, considered as distinct individualities, seem 
to us to have completely disappeared, or to 
appear again only at the bidding of their caprice. 
But this semblance of complete destruction or of 
capricious revival is due merely to the fact that 
actual consciousness accepts at each moment the 
useful, and rejects in the same breath the super 
fluous. Ever bent upon action, it can only ma 
terialize those of our former perceptions which 
can ally themselves with the present perception to 
take a share in the final decision. If it is neces 
sary, when I would manifest my will at a given 
point of space, that my consciousness should go 
successively through those intermediaries or those 
obstacles of which the sum constitutes what we call 
distance in space, so on the other hand it is useful, 
in order to throw light on this action, that my con 
sciousness should jump the interval of time which 
separates the actual situation from a former one 
which resembles it ; and as consciousness goes 


back to the earlier date at a bound, all the inter 
mediate past escapes its hold. The same reasons, 
then, which bring about that our perceptions range 
themselves in strict continuity in space, cause our 
memories to be illumined discontinuously in time. 
We have not, in regard to objects unperceived in 
space and unconscious memories in time, to do 
with two radically different forms of existence ; 
but the exigencies of action are the inverse in the 
one case of what they are in the other. 

But here we come to the capital problem of 
existence, a problem we can only glance at, for 
Existence im- otherwise it would lead us step by step 
m t *h e near t of metaphysics. We will 
merely say that with regard to matters 
^ experience which alone concern us 
nere existence appears to imply two 
either. conditions taken together : (i) presenta 
tion in consciousness ; and (2) the logical or 
causal connexion of that which is so presented 
with what precedes and with what follows. The 
reality for us of a psychical state or of a 
material object consists in the double fact that 
our consciousness perceives them and that they 
form part of a series, temporal or spatial, of which 
the elements determine each other. But these 
two conditions admit of degrees, and it is conceiv 
able that, though both are necessary, they may be 
unequally fulfilled. Thus, in the case of actual 
internal states, the connexion is less close, and 
the determination of the present by the past, leav- 


ing ample room for contingency, has not the 
character of a mathematical derivation ; but 
then, presentation in consciousness is perfect, 
an actual psychical state yielding the whole 
of its content in the act itself whereby we 
perceive it. On the contrary, if we are dealing 
with external objects it is the connexion which is 
perfect, since these objects obey necessary laws ; 
but then the other condition, presentation in con 
sciousness, is never more than partially fulfilled, 
for the material object, just because of the multi 
tude of unperceived elements by which it is linked 
with all other objects, appears to enfold within 
itself and to hide behind it infinitely more than 
it allows to be seen. We ought to say, then, that 
existence, in the empirical sense of the word, 
always implies conscious apprehension and regular 
connexion ; both at the same time but in different 
degrees. But our intellect, of which the function 
is to establish clear-cut distinctions, does not so 
understand things. Rather than admit the 
presence in all cases of the two elements mingled 
The fallacy in varvin g proportions, it prefers to 

dis- dissociate them, and thus attribute 


two kinds of to external objects on the one hand, and 


characterized to internal states on the other, two radi- 

the one by 

conscious :ally different modes of existence, each 


and the other characterized by the exclusive presence of 

by regular 

connexion. the condition which should be regarded 
as merely preponderating. Then the existence of 
psychical states is assumed to consist entirely in 


their apprehension by consciousness, and that of ex 
ternal phenomena, entirely also, in the strict order of 
their concomitance and their succession. Whence 
the impossibility of leaving to material objects, 
existing, but unperceived, the smallest share in 
consciousness, and to internal unconscious states 
the smallest share in existence. We have shown, 
at the beginning of this book, the consequences 
of the first illusion : it ends by falsifying our 
representation of matter. The second, comple 
mentary to the first, vitiates our conception of 
mind by casting over the idea of the unconscious 
an artificial obscurity. The whole of our past 
psychical life conditions our present state, with 
out being its necessary determinant ; whole, 
also, it reveals itself in our character, although 
no one of its past states manifests itself explicitly 
in character. Taken together, these two con 
ditions assure to each one of the past psychological 
states a real, though an unconscious, existence. 

But we are so much accustomed to reverse, 
for the sake of action, the real order of things, 
But, if mem- we are so strongly obsessed by images 
"s 1 * 6 " drawn from space, that we cannot hin- 
^er ourselves from asking where mem- 
or ies are stored up. We understand 
the Question, ^hat physico-chemical phenomena take 
place in the brain, that the brain is in the body, 
the body in the air which surrounds it, etc. ; 
but the past, once achieved, if it is retained, 
where is it ? To locate it in the cerebral sub- 



stance, in the state of molecular modification, 
seems clear and simple enough, because then we 
have a receptacle, actually given, which we have 
only to open in order to let the latent images 
flow into consciousness. But if the brain cannot 
serve such a purpose, in what warehouse shall 
we store the accumulated images ? We forget 
that the relation of container to content borrows 
its apparent clearness and universality from the 
necessity laid upon us of always opening out space 
in front of us, and of always closing duration be 
hind us. Because it has been shown that one thing 
is within another, the phenomenon of its preserva 
tion is not thereby made any clearer. We may 
even go further : let us admit for a moment that 
the past survives in the form of a memory stored 
in the brain ; it is then necessary that the brain, 
in order to preserve the memory, should pre 
serve itself. But the brain, in so far as it is an 
image extended in space, never occupies more 
than the present moment : it constitutes, with all 
the rest of the material universe, an ever renewed 
section of universal becoming. Either, then, 
you must suppose that this universe dies and is 
born again miraculously at each moment of dura 
tion, or you must attribute to it that continuity of 
existence which you deny to consciousness, and 
make of its past a reality which endures and is. pro 
longed into its present. So that you have gained 
nothing by depositing the memories in matter, 
and you find yourself, on the contrary, compelled 


to extend to the totality of the states of the ma 
terial world that complete and independent sur 
vival of the past which you have just refused to 
psychical states. This survival of the past per 
se forces itself upon philosophers, then, under one 
form or another ; and the difficulty that we have 
in conceiving it comes simply from the fact 
that we extend to the series of memories, in time, 
that obligation of containing and being contained 
which appHes only to the collection of bodies 
instantaneously perceived in space. The funda 
mental illusion consists in transferring to dura 
tion itself, in its continuous flow, the form of 
the instantaneous sections which we make in it. 

But how can the past, which, by hypothesis, 

has ceased to be, preserve itself ? Have we not 

here a real contradiction ? We reply 

The past has ., , . , , , f, 

Dot ceased to that the question is just whether the 

exist ; it has . , 

only ceased past has ceased to exist or whether it 
has simply ceased to be useful. You 
define the present in an arbitrary manner as that 
which is, whereas the present is simply what is 
being made. Nothing is less than the present 
moment, if you understand by that the indivisible 
limit which divides the past from the future. 
When we think this present as going to be, it exists 
not yet ; and when we think it as existing, it is 
already past. If, on the other hand, what you are 
considering is the concrete present such as it is act 
ually lived by consciousness, we may say that this 
present consists, in large measure, in the immediate 



past. In the fraction of a second which covers 
the briefest possible perception of light, billions 
of vibrations have taken place, of which the first 
is separated from the last by an interval which is 
enormously divided. Your perception, however 
instantaneous, consists then in an incalculable 
multitude of remembered elements ; and in truth 
every perception is already memory. Practically 
we perceive only the past, the pure present being 
the invisible progress of the past gnawing into 
the future. 

Consciousness, then, illumines, at each moment 
of tune, that immediate part of the past which, 
impending over the future, seeks to realize 
and to associate with it. Solely preoccupied in 
thus determining an undetermined future, con 
sciousness may shed a little of its light on those 
of our states, more remote in the past, which can 
be usefully combined with our present state, 
that is to say, with our immediate past : the rest 
remains in the dark. It is in this illuminated part 
of our history that we remain seated, in virtue of 
the fundamental law of life, which is a law of 
action : hence the difficulty we experience in con 
ceiving memories which are preserved in the 
shadow. Our reluctance to admit the integral 
survival of the past has its origin, then, in the 
very bent of our psychical life, an unfolding of 
states wherein our interest prompts us to look at 
that which is unrolling, and not at that which is 
entirely unrolled. 


So we return, after a long digression, to our 
point of departure. There are, we have said, two 
The two memories which are profoundly dis- 

tinct : the one > fixed in the organism, 
is nothing else but the complete set of 
uppoX d the intelligently constructed mechanisms 
other> which ensure the appropriate reply to 

the various possible demands. This memory 
enables us to adapt ourselves to the present situa 
tion ; through it the actions to which we are sub 
ject prolong themselves into reactions that are 
sometimes accomplished, sometimes merely nas 
cent, but always more or less appropriate. Habit 
rather than memory, it acts our past experience 
but does not call up its image. The other is the 
true memory. Co-extensive with consciousness, 
it retains and ranges alongside of each other all 
our states in the order in which they occur, 
leaving to each fact its place and consequently 
marking its date, truly moving in the past and 
not, like the first, in an ever renewed present. But, 
in marking the profound distinction between 
these two forms of memory, we have not shown 
their connecting link. Above the body, with its 
mechanisms which symbolize the accumulated 
effort of past actions, the memory which ima 
gines and repeats has been left to hang, as it 
were, suspended in the void. Now, if it be 
true that we never perceive anything but our 
immediate past, if our consciousness of the 
present is already memory, the two terms 


which had been separated to begin with cohere 
closely together. Seen from this new point of 
view, indeed, our body is nothing but that part 
of our representation which is ever being born 
again, the part always present, or rather that 
which at each moment is just past. Itself an 
image, the body cannot store up images, since 
it forms a part of the images; and this is why it 
is a chimerical enterprise to seek to localize past 
or even present perceptions in the brain : they 
are not in it ; it is the brain that is in them. But 
this special image which persists in the midst of 
the others, and which I call my body, constitutes 
at every moment, as we have said, a section of 
the universal becoming. It is then the place of 
passage of the movements received and thrown 
back, a hyphen, a connecting link between the 
things which act upon me and the things upon 
which I act, the seat, in a word, of the sensori- 
motor phenomena. If I represent by a cone SAB 
the totality of the recollections accumulated in 
my memory, the base AB, situated in the past, 
remains motionless, while the summit S, which 
indicates at all times my present, moves forward 
unceasingly, and unceasingly also touches the 
moving plane P of my actual representation 
of the universe. At S the image of the body 
is concentrated ; and, since it belongs to the 
plane P, this image does but receive and restore 
actions emanating from all the images of which 
the plane is composed. 


The bodily memory, made up of the sum of the 
sensori-motor systems organized by habit, is then 
a quasi-instantaneous mem 
ory to which the true memory 
of the past serves as base. 
Since they are not two separ 
ate things, since the first is 
only, as we have said, the 
pointed end, ever moving, 
inserted by the second in the 
shifting plane of experience,it is natural that the two 
functions should lend each other a mutual support. 
So, on the one hand, the memory of the past offers 
to the sensori-motor mechanisms all the recollections 
capable of guiding them in their task and of giv 
ing to the motor reaction the direction suggested 
by the lessons of experience. It is in just this 
that the associations of contiguity and likeness 
consist. But, on the other hand, the sensori-motor 
apparatus furnish to ineffective, that is uncon 
scious, memories, the means of taking on a body, 
of materializing themselves, in short of becoming 
present. For, that a recollection should reappear 
in consciousness, it is necessary that it should 
descend from the heights of pure memory down 
to the precise point where action is taking place. 
In other words, it is from the present that comes 
the appeal to which memory responds, and it 
is from the sensori-motor elements of present 
action that a memory borrows the warmth which 
gives it life. 


Is it not by the constancy of this agreement, 
by the precision with which these two comple 
mentary memories insert themselves 
oood sense each into the other, that we recognize a 

consists main- o 

X "* . m * king well-balanced mind, that is to say, 

the right use J 

of spontan- m fact, a man nicely adapted to life ? 

eons memory, J 

The characteristic of the man of action 
is the promptitude with which he summons 
to the help of a given situation all the mem 
ories which have reference to it ; but it is also the 
insurmountable barrier which encounter, when they 
present themselves on the threshold of his con 
sciousness, memories that are useless or indiffer 
ent. To live only in the present, to respond 
to a stimulus by the immediate reaction which 
prolongs it, is the mark of the lower animals : 
the man who proceeds in this way is a man of im 
pulse. But he who lives in the past for the mere 
pleasure of living there, and in whom recollections 
emerge into the light of consciousness without 
any advantage for the present situation, is 
hardly better fitted for action : here we have no 
man of impulse, but a dreamer. Between these 
two extremes lies the happy disposition of a 
memory docile enough to follow with precision 
all the outlines of the present situation, but ener 
getic enough to resist all other appeal. Good 
sense, or practical sense, is probably nothing but 

The extraordinary development of spontaneous 
memory in most children is due to the fact that 


they have not yet persuaded their memory to 
remain bound up with their conduct. They 
usually follow the impression of the moment, 
and as with them action does not bow to the 
suggestions of memory, so neither are their recol 
lections limited to the necessities of action. 
They seem to retain with greater facility only 
because they remember with less discernment. 
The apparent diminution of memory, as intellect 
developes, is then due to the growing organi 
zation of recollections with acts. Thus con 
scious memory loses in range what it gains 
in force of penetration : it had at first the 
facility of the memory of dreams, but then 
it was actually dreaming. Indeed we observe 
this same exaggeration of spontaneous mem 
ory in men whose intellectual development 
hardly goes beyond that of childhood. A mis 
sionary, after preaching a long sermon to some 
African savages, heard one of them repeat it tex- 
tually, with the same gestures, from beginning to 
end. 1 

But, if almost the whole of our past is hidden 
from us because it is inhibited by the necessities 
of present action, it will find strength to cross the 
threshold of consciousness in all cases where we 
renounce the interests of effective action to replace 
ourselves, so to speak, in the life of dreams. Sleep, 
natural or artificial, brings about an indifference 

1 Kay, Memory and How to Improve it. New York, 1888, 
p. 18. 


of just this kind. It has been recently suggested 
that in sleep there is an interruption of the con 
tact between the nervous elements, motor and 
sensory. 1 Even if we do not accept this in 
genious hypothesis, it is impossible not to see 
in sleep a relaxing, even if only functional, of 
the tension of the nervous system, ever ready, 
Baring waking hours, to prolong by an appropriate 
reaction the stimulation received . Now the exalta 
tion of the memory in certain dreams and in cer 
tain somnambulistic states is well known. Mem 
ories which we believed abolished then reappear 
with striking completeness ; we live over again, 
in all their detail, forgotten scenes of childhood ; 
we speak languages which we no longer even 
remember to have learnt. But there is nothing 
more instructive in this regard than what hap 
pens in cases of sudden suffocation, in men 
drowned or hanged. The man, when brought to 
life again, states that he saw, in a very short 
time, all the forgotten events of his life passing 
before him with, great rapidity, with their smallest 
circumstances and in the very order in which 
they occurred.* 

1 Mathias Duval, Theorie histologique du sommeil (C. R. de 
la Soc. de Biologie, 1895, p. 74). Cf. Lepine, ibid., p. 85 and 
Revue de Medecine, Aug. 1894, and especially Pupin, Le 
neurone et les hypotheses histologiques, Paris, 1896. 

2 Forbes Winslow, Obscure Diseases of the Brain, p. 25 
e t S eq. Ribot, Maladies de la memoir e, p. 139 et seq. Mauro, 
Le sommeil et les reves, Paris, 1878, p. 439. Egger, Lc moi 
des mouiants (Revue philosophique , Jan. and Oct. 1896). 


A human being who should dream his life in 
stead of living it would no doubt thus keep before 
spontaneous his eyes at each moment the infinite mul- 
differ- titude of the details of his past history. 
8 And, on the other hand, the man who 

should repudiate this memory with all 
place arises that it begets would be continually 
idea. acting his life instead of truly repre 

senting it to himself: a conscious automaton, 
he would follow the lead of useful habits which 
prolong into an appropriate reaction the stimula 
tion received. The first would never rise above 
the particular, or even above the individual ; 
leaving to each image its date in time and its 
position in space, he would see wherein it differs 
from others and not how it resembles them. The 
other, always swayed by habit, would only dis 
tinguish in any situation that aspect in which it 
practically resembles former situations ; incapable, 
doubtless, of thinking universals, since every 
general idea implies the representation, at least 
virtual, of a number of remembered images, he 
would nevertheless move in the universal, habit 
being to action what generality is to thought. 
But these two extreme states, the one of an 
entirely contemplative memory which appre 
hends only the singular in its vision, the other 
of a purely motor memory which stamps the note 

Cf. Ball s dictum : Memory is a faculty which loses nothing 
and records everything. (Quoted by Rouillard, Les amnesics 
[medical thesis], Paris, 1885, p. 25.) 


of generality on its action, are really apart and 
are fully visible only in exceptional cases. In 
normal life they are interpenetrating, so that 
each has to abandon some part of its original 
purity. The first reveals itself in the recollection 
of differences, the second in the perception of 
resemblances : at the meeting of the two currents 
appears the general idea. 

We are not here concerned to settle once for all 
the whole question of general ideas. Some there 
are that have not originated in perception alone, 
and that have but a very distant connexion 
with material objects. We will leave these 
on one side, and consider only those general 
ideas that are founded on what we have 
called the perception of similarity. We will try 
to follow pure memory, integral memory, in the 
continuous effort which it makes to insert itself 
into motor habit. In this way we may throw 
more light upon the office and nature of this 
memory, and perhaps make clearer, at the same 
time, by regarding them in this particular aspect, 
the two equally obscure notions of resemblance 
and of generality. 

If we consider as closely as possible the diffi 
culties of a psychological order which surround 
the problem of general ideas, we shall 

Nominalism IT , . , - 

and concep- come, we believe, to enclose them in 
revolve in a this circle : to generalize, it is first of 
leading back all necessary to abstract, but to abstract 

to the other. . , . 

to any purpose we must already know 


how to generalize. Round this circle gravitate, 
consciously or unconsciously, nominalism and 
conceptualism, each doctrine having in its fav 
our mainly the insufficiency of the other. The 
nominalists, retaining of the general idea only its 
extension, see in it merely an open and unlimited 
series of individual objects. The unity of the 
idea can then, for them, consist only in the identity 
of the symbol by which we designate indiffer 
ently all these distinct objects. According to 
them, we begin by perceiving a thing, and then 
we assign to it a word : this word, backed by 
the faculty or the habit of extending itself to an 
unlimited number of other things, then sets up for 
a general idea. But, in order that the word 
should extend and yet limit itself to the objects 
which it designates, it is necessary that these 
objects should offer us resemblances which, 
when we compare them, shall distinguish them 
from all the objects to which the word does not 
apply. Generalization does not, consequently, 
occur without our taking into account qualities 
that have been found to be common and there 
fore considered in the abstract ; and from step to 
step, nominalism is thus led to define the general 
idea by its intension and not merely by its exten 
sion, as it set out to do. It is just from this in 
tension that conceptualism starts ; the intellect, on 
this theory, resolves the superficial unity of the 
individual into different qualities, each of which, 
isolated from the individual which limited it, be- 


comes by that very isolation representative of a 
genus. Instead of regarding each genus as includ 
ing actually a multiplicity of objects, it is now main 
tained, on the contrary, that each object involves 
potentially, and as so many qualities which it holds 
captive, a multiplicity of genera. But the ques 
tion before us is whether individual qualities, 
even isolated by an effort of abstraction, do not 
remain individual ; and whether, to make them 
into genera, a new effort of the mind is not re 
quired, by which it first bestows on each quality 
a name, and then collects under this name a 
multitude of individual objects. The whiteness 
of a lily is not the whiteness of a snow-field ; they 
remain, even as isolated from the snow and the 
Uly, snow-white or lily-white. They only forego 
their individuality if we consider their likeness in 
order to give them a common name ; then, apply 
ing this name to an unlimited number of similar 
objects, we throw back upon the quality, by a 
sort of ricochet, the generality which the word 
went out to seek in its application to things. 
But, reasoning in this way, do we not return to 
the point of view of extension, which we just now 
abandoned ? We are then, in truth, revolving 
in a circle, nominalism leading us to conceptualism, 
and conceptualism bringing us back to nominalism. 
Generalization can only be effected by extracting 
common qualities ; but, that qualities should 
appear common, they must have already been 
subjected to a process of generalization. 


Now, when we get to the bottom of these two 
opposite theories, we find in them a common 
postulate ; each will have it that we start from 
the perception of individual objects. The first 
composes the genus by an enumeration ; the 
second disengages it by an analysis ; but it is 
upon individuals, considered as so many realities 
given to immediate intuition, that both analysis 
and enumeration are supposed to bear. This is 
the postulate. In spite of its apparent obvious 
ness, we must expect to find, and we do indeed 
find, that experience belies it. 

A priori, indeed, we may expect the clear dis 

tinction of individual objects to be a luxury of 

perception, just as the clear repre- 

The clear f . J ... . 

perception oi sentation of general ideas is a refinement 
objects and of the intellect. The full conception 

the clear .. , , , 

conception oi of genera is no doubt proper to human 

te thought ; it demands an effort of reflex- 

development. -, , . , r 

ion, by which we expunge from a repre 
sentation the details of time and place. But the re 
flexion on these details a reflexion without which 
the individuality of objects would escape us pre 
supposes a faculty of noticing differences, and 
therefore a memory of images, which is certainly 
the privilege of man and of the higher animals. 
It would seem, then, that we start neither 
from the perception of the individual nor from 
the conception of the genus, but from an inter 
mediate knowledge, from a confused sense of the 
striking quality or of resemblance : this sense, 


equally remote from generality fully conceived 
and from individuality clearly perceived, begets 
them both by a process of dissociation. Reflective 
analysis clarifies it into the general idea ; dis 
criminative memory solidifies it into a perception 
of the individual. 

But this will be more clearly evident if we go 
back to the purely utilitarian origin of our per 
ception of things. That which interests us in a 
given situation, that which we are likely to grasp 
in it first, is the side by which it can respond to 
a tendency or a need. But a need goes straight 
to the resemblance or quality ; it cares little for 
individual differences. To this discernment of the 
useful we may surmise that the perception of 
animals is, in most cases, confined. It is grass 
in general which attracts the herbivorous animal : 
the colour and the smell of grass, felt and ex 
perienced as forces, (we do not go so far as to 
say, thought as qualities or genera) are the sole 
immediate data of its external perception. On this 
For the background of generality or of resem- 
l ance the animal s memory may show 
U P con trasts from which will issue dif- 
ferentiations ; it will then distinguish 
one countryside from another, one field 
from another field ; but this is, we repeat, the super 
fluity of perception, not a necessary part. It may 
be urged that we are only throwing the problem 
further back, that we are merely relegating to 
the unconscious the process by which similarity 


is discovered and genera are constituted. But 
we relegate nothing to the unconscious, for the 
very simple reason that it is not, in our opinion, 
an effort of a psychological nature which here dis 
engages similarity ; this similarity acts objectively 
like a force, and provokes reactions that are iden 
tical in virtue of the purely physical law which re 
quires that the same general effects should follow the 
same profound causes. Hydrochloric acid always 
acts in the same way upon carbonate of lime 
whether in the form of marble or of chalk yet 
we do not say that the acid perceives in the various 
species the characteristic features of the genus. 
Now there is no essential difference between the 
process by which this acid picks out from the 
salt its base, and the act of the plant which 
invariably extracts from the most diverse soils 
those elements that serve to nourish it. Make 
one more step ; imagine a rudimentary con 
sciousness such as that of an amoeba in a drop 
of water : it will be sensible of the resemblance, 
and not of the difference, in the various organic 
substances which it can assimilate. In short, 
we can follow from the mineral to the plant, 
from the plant to the simplest conscious beings, 
from the animal to man, the progress of the 
operation by which things and beings seize from 
out their surroundings that which attracts them, 
that which interests them practically, without 
needing any effort of abstraction, simply because 
the rest of their surroundings takes no hold upon 


them : this similarity of reaction following actions 
superficially different is the germ which the human 
consciousness developes into general ideas. 

Consider, indeed, the purpose and function 
of our nervous system as far as we can infer 
them from its structure. We see a great 
so that the variety of mechanisms of perception, 
K5)eli- dea a ^ D0un d, through the intermediary 
iTis ed e b P ?e- re of the centres, to the same motor 
sented. apparatus. Sensation is unstable ; it 
can take the most varied shades ; the motor 
mechanism, on the contrary, once set going, will 
invariably work in the same way. We may then 
suppose perceptions as different as possible in 
their superficial details : if only they are continued 
by the same motor reactions, if the organism can 
extract from them the same useful effects, if they 
impress upon the body the same attitude, some 
thing common will issue from them, and the general 
idea will have been felt and passively experienced, 
before being represented. Here then we escape 
at last from the circle in which we at first appeared 
to be confined. In order to generalize, we said, 
we have to abstract similarity, but in order to 
disengage similarity usefully we must already 
know how to generalize. There really is no circle, 
because the similarity, from which the mind starts 
when it first begins the work of abstraction, is 
not the similarity at which the mind arrives when 
it consciously generalizes. That from which it 
starts is a similarity felt and lived ; or, if you prefer 


the expression, a similarity which is automatically 
acted. That to which it returns is a similarity in 
telligently perceived, or thought. And it is precisely 
in the course of this progress that are built up, 
by the double effort of the understanding and of 
the memory, the perception of individuals and 
the conception of genera, memory grafting dis 
tinctions upon resemblances which have been 
spontaneously abstracted, the understanding dis 
engaging from the habit of resemblances the clear 
idea of generality. This idea of generality was, 
in the beginning, only our consciousness of a likeness 
of attitude in a diversity of situations ; it was 
habit itself, mounting from the sphere of move 
ment to that of thought. But from genera so 
sketched out mechanically by habit we have 
passed, by an effort of reflexion upon this very 
process, to the general idea of genus ; and when 
that idea has been once constituted, we have con 
structed (this time voluntarily) an unlimited num 
ber of general notions. It is not necessary here to 
follow the intellect into the detail of this con 
struction. It is enough to say that the under 
standing, imitating the effort of nature, has also 
set up motor apparatuses, artificial in this case, to 
make a limited number of them answer to an un 
limited number of individual objects : the assem 
blage of these mechanisms is articulate speech. 

Yet these two divergent operations of the mind, 
the one by which it discerns individuals, the other 
by which it constructs genera, are far from demand- 


ing the same effort or progressing with the same 
rapidity. The first, requiring only the inter 
vention of memory, takes place from the outset 
of our experience ; the second goes on indefinitely 
without ever reaching its goal. The first issues in 
the formation of stable images, which in their turn 
are stored up in memory ; the second comes out in 
representations that are unstable and evanescent. 
We must dwell on this last point, for we touch 
here an essential problem of mental life. 

The essence of the general idea, in fact, is to 
be unceasingly going backwards and forwards 
between the plane of action and that of pure 
memory. Let us refer once more to the dia 
gram we traced above. At S is the present 
perception which I have of my body, that is 
to say, of a certain sensori-motor equilibrium. 
Over the surface of the base AB are spread, 
we may say, my recollections in their totality. 
Within the cone so determined the general 
idea oscillates continually between the summit 
S and the base AB. In S it would take the 
clearly defined form of a bodily attitude or of 
an uttered word ; at AB it would wear the aspect, 
no less defined, of the thousand individual images 
into which its fragile unity would break 
up. And that is why a psychology which 

movement" 1 abides by the already done, which- con- 
pfane e< of siders only that which is made and 

tire ignores that which is in the making, 
will never perceive in this movement 

CHAP. Ill 



anything more than the two extremities between 
which it oscillates ; it makes the general idea 
coincide sometimes with the action which mani 
fests it or the word which expresses it, and 
at other times with the multitudinous images, 
unlimited in number, which are its equivalent in 
memory. But the truth is that the general idea 
escapes us as soon as we try to fix it at either of 
the two extremities. It consists in the double 
current which goes from the one to the other, 
always ready either to crystallize into uttered 
words or to evaporate into memories. 

This amounts to saying that between the 
sensori-motor mechanisms figured by the point 
S and the totality of the memories disposed in 
AB there is room, as we indicated in the preceding 
chapter, for a thou 
sand repetitions of our 
psychical life, figured 
by as many sections 
A B , A"B", etc., of the 
same cone. We tend 
to scatter ourselves 
over AB in the measure 
that we detach our 
selves from our sensory 
and motor state to live 
in the life of dreams : 

FIG. 5. 

we tend to concentrate 

ourselves in S in the measure that we attach 

ourselves more firmly to the present reality, 


responding by motor reactions to sensory stimula 
tion. In point of fact, the normal self never stays 
in either of these extreme positions ; it moves 
between them, adopts in turn the positions corre 
sponding to the intermediate sections, or, in other 
words, gives to its representations just enough 
image and just enough idea for them to be able 
to lend useful aid to the present action. 

From this conception of the lower mental life 
the laws of the association of ideas can be deduced. 
But, before we deal with this point, we must first 
show the insufficiency of the current theories of 

That every idea which arises in the mind has 
a relation of similarity or of contiguity with 
But associa- tne previous mental state, we do not 
ie dispute ; but a statement of the kind 
throws no light on the mechanism of as- 
and e oJr ea " sociation ; nor, indeed, does it really tell 
actual needs. us any thing at all. For we should seek 
in vain for two ideas which have not some point 
of resemblance, or which do not touch each other 
somewhere. To take similarity first : however 
profound are the differences which separate two 
images, we shall always find, if we go back high 
enough, a common genus to which they belong, and 
consequently a resemblance which may serve as a 
connecting link between them. And, in regard to 
contiguity, a perception A, as we said before, will 
not evoke by contiguity a former image B, unless 


it recalls to us first an image A which is like it, 
because it is the recollection A , and not the 
perception A, which really touches B in memory. 
However distant, then, we suppose the terms A 
and B from each other, a relation of contiguity 
can always be found between them, provided that 
the intercalated term A bears a sufficiently far 
fetched resemblance to A. This is as much as to 
say that between any two ideas chosen at random 
there is always a resemblance, and always, even, 
contiguity ; so that, when we discover a relation 
of contiguity or of resemblance between two suc 
cessive ideas, we have in no way explained why 
the one evokes the other. 

What we really need to discover is how a choice 
is effected among an infinite number of recollec 
tions which all resemble in some way the present 
perception, and why only one of them, this rather 
than that, emerges into the light of consciousness. 
But this is just what associationism cannot tell 
us, because it has made ideas and images into 
independent entities floating, like the atoms of 
Epicurus, in an inward space, drawing near to 
each other and catching hold of each other when 
chance brings them within the sphere of mutual 
attraction. And if we try to get to the bottom 
of the doctrine on this point, we find that its 
error is that it intellectualizes ideas over much: 
it attributes to them a purely speculative role, 
believes that they exist for themselves and not 
for us, and overlooks the relation which they 


bear to the activity of the will. If memories 
move about, indifferent, in a consciousness that is 
both lifeless and shapeless, there is no reason why 
the present perception should prefer and attract 
any one of them : we can only, in that case, 
note the conjunction when once it has taken 
place and speak of similarity or of contiguity, 
which is merely, at bottom, to express in vague 
terms that our mental states have affinities for 
one another. 

But even of this affinity, which takes the double 
form of contiguity and of similarity, associationism 
can furnish no explanation. The general ten 
dency to associate remains as obscure for us, if we 
adhere to this doctrine, as the particular forms of 
association. Having stiffened individual memory- 
images into ready-made things, given cut and 
dry in the course of our mental life, associa 
tionism is reduced to bringing in, between these 
objects, mysterious attractions of which it is not 
even possible to say beforehand, as of physical 
attraction, by what effects they will manifest 
themselves. For why should an image which is, 
by hypothesis, self-sufficient, seek to accrue to 
itself others either similar or given in contiguity 
with it ? The truth is that this independent 
image is a late and artificial product of the mind- 
In fact, we perceive the resemblance before we per 
ceive the individuals which resemble each other ; 
and, in an aggregate of contiguous parts, we per 
ceive the whole before the parts. We go on from 


similarity to similar objects, embroidering upon 
the similarity, as on their common stuff or canvas, 
the variety of individual differences. And we 
go on also from the whole to the parts, by a process 
of decomposition the law of which will appear 
later, a process which consists in breaking up, 
for the greater convenience of practical life, 
the continuity of the real. Association, then, 
is not the primary fact : dissociation is what 
we begin with, and the tendency of every mem 
ory to gather to itself others must be explained 
by the natural return of the mind to the undivided 
unity of perception. 

But here we discover the radical vice of associa- 
tionism. Given a present perception which forms 
similarity kv turns, with different recollections, 
severa -l associations one after another, 
- there are two ways, as we said, of con- 
th s e s mse e iv" e ce i ym g the mechanism of this associa- 
accounted for. tion. We may suppose that the percep 
tion remains identical with itself, a true psychical 
atom which gathers to itself others just as these 
happen to be passing by. This is the point of 
view of associationism. But there is also another, 
precisely the one which we have indicated in 
our theory of recognition. We have supposed 
that our entire personality, with the totality of 
our recollections, is present, undivided within our 
actual perception. Then, if this perception evokes 
in turn different memories, it is not by a mechan 
ical adjunction of more and more numerous 


elements which, while it remains itself unmoved, 
it attracts around it, but rather by an expansion 
of the entire consciousness which, spreading out 
over a larger area, discovers the fuller detail of 
its wealth. So a nebulous mass, seen through 
more and more powerful telescopes, resolves itself 
into an ever greater number of stars. On the 
first hypothesis (in favour of which there is little 
but its apparent simplicity and its analogy 
with a misunderstood physical atomism), each 
recollection is a fixed and independent being, 
of which we can neither say why it seeks to 
accrue to itself others, nor how it chooses, among 
a thousand memories which should have equal 
rights, those with which to associate itself in 
virtue of similarity or contiguity. We must 
suppose that ideas jostle each other at random, 
or that they exert among themselves mysterious 
forces, and moreover we have against us the 
witness of consciousness, which never shows us 
psychical facts floating as independent entities. 
From the second point of view, we merely state a 
fact, viz. that psychic facts are bound up with 
each other, and are always given together to 
immediate consciousness as an undivided whole 
which reflexion alone cuts up into distinct frag 
ments. What we have to explain, then, is no 
longer the cohesion of internal states, but the 
double movement of contraction and expansion 
by which consciousness narrows or enlarges 
the development of its content. But this move- 


ment, we shall see, is the result of the fun 
damental needs of life ; and we shall also 
see why the associations/ which we appear 
to form in the course of this movement, corre 
spond to all the possible degrees of so-called con 
tiguity and resemblance. 

Let us, for a moment, suppose our psychical 
life reduced to sensori-motor functions alone. 
They should ^ n other words, suppose ourselves placed 
first ,<mtr df m the diagrammatic figure on page 211 
?c?on. wher at the P om t S, which corresponds to the 
they coincide ; g rea t e st possible simplification of our 
mental life. In this state every perception 
spontaneously prolongs itself into appropriate 
reactions; for analogous former perceptions 
have set up more or less complex motor 
apparatus, which only await a recurrence of 
the same appeal in order to enter into play. 
Now there is, in this mechanism, an associa 
tion of similarity, since the present perception 
acts in virtue of its likeness to past perceptions ; 
and there is also an association of contiguity, 
since the movements which followed those 
former perceptions reproduce themselves, and 
may even bring in their train a vast num 
ber of actions co-ordinate with the first. Here 
then we seize association of similarity and 
association of contiguity at their Very source, 
and at a point where they are almost confounded 
in one not indeed thought, but acted and lived. 
They are not contingent forms of our psychical 


life ; they represent the two complementary 
aspects of one and the same fundamental tendency, 
the tendency of every organism to extract from 
a given situation that in it which is useful, and to 
store up the eventual reaction in the form of a 
motor habit, that it may serve other situations 
of the same kind. 

Let us jump now to the other extremity of 
our mental life, and, following our line of thought, 
go from the psychical existence which 
o?tt?3!S? f is merety acted, to that which is ex- 
clusively dreamed. In other words, 
^ us pl ace ourselves on the base 
AB of memory (page 211) where all the 
events of our past life are set out in their small 
est details. A consciousness which, detached from 
action, should thus keep in view the totality of 
its past, would have no reason to dwell upon one 
part of this past rather than upon another. In 
one sense, all its recollections would differ from 
its present perception, for, if we take them with 
the multiplicity of their detail, no two memories 
are ever precisely the same thing. But, in another 
sense, any memory may be set alongside the pre 
sent situation : it would be sufficient to neglect in 
this perception and in this memory just enough 
detail for similarity alone to appear. Moreover, 
the moment that the recollection is linked with 
the perception, a multitude of events contig 
uous to the memory are thereby fastened to the 
perception an indefinite multitude, which is only 


limited at the point at which we choose to stop 
it. The necessities of life are no longer there 
to regulate the effect of similarity, and conse 
quently of contiguity ; and as, after all, everything 
resembles everything else, it follows that any 
thing can be associated with anything. In the 
first case the present perception continued itself 
in determinate movements ; now it melts into 
an infinity of memories, all equally possible. 
At AB association would provoke an arbitrary 
choice, and in S an inevitable deed. 

But these are only two extreme limits, at 
which the psychologist must place himself alter 
nately for convenience of study, and 

Now normal . . . ,. - ., . 

psychical which are really never reached in prac- 

life oscillates . _, . % . . 

between these tice. There is not, in man at least, a 

two extremes, . 

according to purely senson-motor state, any more 

the degree of Jt , .... . .. 

tension in than there is in mm an imaginative 
life without some slight activity be 
neath it. Our psychical life, as we have said, 
oscillates normally between these two extremes. 
On the one hand, the sensori-motor state S marks 
out the present direction of memory, being no 
thing else, in fact, than its actual and acting 
extremity ; and on the other hand this memory 
itself, with the totality of our past, is continually 
pressing forward, so as to insert the largest 
possible part of itself into the present action. 
From this double effort result, at every mo 
ment, an infinite number of possible states 
of memory, states figured by the sections 


A B , A B" of our diagram. These are, as we 
have said, so many repetitions of the whole 
of our past life. But each section is larger or 
smaller according to its nearness to the base or 
to the summit ; and moreover each of these 
complete representations of the past brings to 
the light of consciousness only that which can 
fit into the sensori-motor state, and consequently 
that which resembles the present perception 
from the point of view of the action to be accom 
plished. In other words, memory, laden with 
the whole of the past, responds to the appeal 
of the present state by two simultaneous move 
ments, one of translation, by which it moves 
in its entirety to meet experience, thus contracting 
more or less, though without dividing, with a 
view to action ; the other of rotation upon itself, 
by which it turns towards the situation of the 
moment, presenting to it that side of itself which 
may prove to be the most useful. To these 
varying degrees of contraction correspond the 
various forms of association by similarity. 

Everything happens, then, as though our 
recollections were repeated an infinite number 
Associations of times in these many possible reduc- 

of similarity . , ... _, , 

are more tions of our past life. They take a 

memory is more common form when memory 

near the plane , . , , . , 

of action, more shrinks most, more personal when it 
ft 6 withdraws widens out, and they thus enter into 
plane of dream, an unlimited number of different sys- 
tematizations. A word from a foreign language, 


uttered in my hearing, may make me think of 
that language in general or of a voice which once 
pronounced it in a certain way. These two 
associations by similarity are not due to the 
accidental arrival of two different representations, 
which chance brought by turns within the attract 
ing influence of the actual perception. They 
answer to two different mental dispositions, to 
two distinct degrees of tension of the memory; 
in the latter case nearer to the pure image, in 
the former more disposed towards immediate 
response, that is to say, to action. To classify 
these systems, to discover the law which binds 
them respectively to the different tones of 
our mental life, to show how each of these tones 
is itself determined by the needs of the moment 
and also by the varying degree of our personal 
effort, would be a difficult task : the whole of 
this psychology is yet to do, and for the moment 
we do not even wish to attempt it. But every 
one is clearly aware of the existence of these laws, 
and of stable relations of this kind. We know, for 
instance, when we read a psychological novel, 
that certain associations of ideas there depicted 
for us are true, that they may have been lived ; 
others offend us, or fail to give us an impression 
of reality, because we feel in them the effect of 
a connexion, mechanically and artificially brought 
about, between different mental levels, as though 
the author had not taken care to maintain him 
self on that plane of the mental life which he 


had chosen. Memory has then its successive 
and distinct degrees of tension or of vitality: 
they are certainly not easy to define, but the 
painter of mental scenery may not with impunity 
confound them. Pathology, moreover, here con 
firms by means, it is true, of coarser examples 
a truth of which we are all instinctively 
aware. In the systematized amnesias of hyster 
ical patients, for example, the recollections which 
appear to be abolished are really present ; but 
they are probably all bound up with a certain 
determined tone of intellectual vitality in which 
the subject can no longer place himself. 

Just as there are these different planes, infinite 
in number, for association by similarity, so there 
are with association by contiguity. In 
J *J at us t ^ ie extreme plane, which represents 
diat?betwe e en ^ e ^ase ^ m emory, there is no recol- 
the two - lection which is not linked by contiguity 

tremes, the J o J 

same memo- w ith the totality of the events which pre- 

nes are sys- J 

tematizedin ce( J e an( J ^Q ^th those which follow 
diverse ways. 

it. Whereas, at the point in space where 
our action is concentrated, contiguity brings back, 
in the form of movement, only the reaction which 
immediately followed a former similar perception. 
As a matter of fact, every association by conti 
guity implies a position of the mind intermediate 
between the two extreme limits. If, here again, we 
imagine a number of possible repetitions of the total 
ity of our memories, each of these copies of our 
past life must be supposed to be cut up, in its own 


way, into definite parts, and the cutting up is 
not the same when we pass from one copy to 
another, each of them being in fact character 
ized by the particular kind of dominant mem 
ories on which the other memories lean as 
on supporting points. The nearer we come to 
action, for instance, the more contiguity tends 
to approximate to similarity and to be thus dis 
tinguished from a mere relation of chronological 
succession : thus we cannot say of the words 
of a foreign language, when they call each other 
up in memory, whether they are associated by 
similarity or by contiguity. On the contrary, 
the more we detach ourselves from action, real or 
possible, the more association by contiguity tends 
merely to reproduce the consecutive images 
of our past life. It is impossible to enter 
here into a profound study of these different 
systems. It is sufficient to point out that these 
systems are not formed of recollections laid side 
by side like so many atoms. There are always 
some dominant memories, shining points round 
which the others form a vague nebulosity. These 
shining points are multiplied in the degree in 
which our memory expands. The process of local 
izing a recollection in the past, for instance, can 
not at all consist, as has been said, in plunging 
into the mass of our memories as into a bag, to 
draw out memories, closer and closer to each 
other, between which the memory to be localized 
may find its place. By what happy chance 


could we just hit upon on a growing number of 
intercalary recollections ? The work of localiza 
tion consists, in reality, in a growing effort of ex 
pansion, by which the memory, always present in 
its entirety to itself, spreads out its recollections 
over an ever wider surface and so ends by dis 
tinguishing, in what was till then a confused mass, 
the remembrance which could not find its proper 
place. Here again, moreover, the pathology of 
memory is instructive. In retrogressive amnesia, 
the recollections which disappear from conscious 
ness are probably preserved in remote planes 
of memory, and the patient can find them there 
by an exceptional effort like that which is effected 
in the hypnotic state. But on the lower planes 
these memories await, so to speak, the dominant 
image to which they may be fastened. A sharp 
shock, a violent emotion, forms the decisive 
event to which they cling ; and if this event, by 
reason of its sudden character, is cut off from 
the rest of our history, they follow it into 
oblivion. We can understand, then, that the 
oblivion which follows a physical or moral shock 
should include the events which immediately 
preceded it a phenomenon which is very difficult 
to explain in all other conceptions of memory. 
Let us remark in passing that if we refuse to 
attribute some such waiting to recent, and even to 
relatively distant, recollections, the normal work 
of memory becomes unintelligible. For every 
event of which the recollection is now imprinted 


on the memory, however simple we suppose it 
to be, has occupied a certain time. The percep 
tions which filled the first period of this interval, 
and now form with the later perceptions an 
undivided memory, were then really loose as 
long as the decisive part of the event had not 
occurred and drawn them along. Between the 
disappearance of a memory with its various pre 
liminary details, and the abolition, in retrogres 
sive amnesia, of a greater or less number of recol 
lections previous to a given event, there is, then, 
merely a difference of degree and not of kind. 

From these various considerations on the lower 
mental life results a certain view of intellectual 
since the equilibrium. This equilibrium will be 
u P set on ly by a perturbation of the 
or- elements which serve as its matter. 
f We cannot here go into questions of 
u the depend mental pathology ; yet neither can we 
thesSsori? f avoid them entirely, since we are 
motor system, endeavouring to discover the exact 
relation between body and mind. 

We have supposed that the mind travels unceas 
ingly over the interval comprised between its two 
extreme limits, the plane of action and the plane of 
dream. Let us suppose that we have to make a 
decision. Collecting, organizing the totality of its 
experience in what we call its character, the mind 
causes it to converge upon actions in which we 
shall afterwards find, together with the past 



which is their matter, the unforeseen form which is 
stamped upon them by personality ; but the action 
is not able to become real unless it succeeds in 
encasing itself in the actual situation, that is to 
say, in that particular assemblage of circumstances 
which is due to the particular position of the body 
in time and space. Let us suppose, now, that we 
have to do a piece of intellectual work, to form 
a conception, to extract a more or less general 
idea from the multiplicity of our recollections. 
A wide margin is left to fancy on the one hand, 
to logical discernment on the other ; but, if the 
idea is to live, it must touch present reality on 
some side; that is to say, it must be able, from 
step to step, and by progressive diminutions or 
contractions of itself, to be more or less acted 
by the body at the same time as it is thought 
by the mind. Our body, with the sensations 
which it receives on the one hand and the 
movements which it is capable of executing on 
the other, is, then, that which fixes our mind, 
and gives it ballast and poise. The activity of 
the mind goes far beyond the mass of accumulated 
memories, as this mass of memories itself is 
infinitely more than the sensations and move 
ments of the present hour ; but these sensations 
and these movements condition what we may 
term our attention to life, and that is why every 
thing depends on their cohesion in the normal 
work of the mind, as in a pyramid which should 
stand upon its apex. 


If, moreover, we cast a glance at the minute 
structure of the nervous system as recent dis 
coveries have revealed it to us, we see every 
where conducting lines, nowhere any centres. 
Threads placed end to end, of which the 
extremities probably touch when the current 
passes : this is all that is seen. And perhaps 
this is all there is, if it be true that the body is 
only a place of meeting and transfer, where stimula 
tions received result in movements accomplished, as 
we have supposed it to be throughout this work. 
But these threads which receive disturbances or 
stimulations from the external world and return 
them to it in the form of appropriate reactions, 
these threads so beautifully stretched from the 
periphery to the periphery, are just what ensure 
by the solidity of their connexions and the 
precision of their interweaving the sensori- 
motor equilibrium of the body, that is to say 
its adaptation to the present circumstances. 
Relax this tension or destroy this equilibrium: 
everything happens as if attention detached 
itself from life. Dreams and insanity appear to 
be little else than this. 

sleep and We were speaking just now of the 
rec ent hypothesis which attributes 
slee P to an interruption of the soli- 
mSto?fnnc- darity among the neurons. Even if 
which they we ^ not accept this hypothesis 
Jresen^ (which is, however, confirmed by some 
reality. curious experiments) we must suppose, 


in deep sleep, at least a functional break in the 
relation established in the nervous system be 
tween stimulation and motor reaction. So that 
dreams would always be the state of a mind 
of which the attention was not fixed by the 
sensori-motor equilibrium of the body. And it 
appears more and more probable that this re 
laxing of tension in the nervous system is due 
to the poisoning of its elements by products of 
their normal activity accumulated in the waking 
state. Now, in every way dreams imitate insanity. 
Not only are all the psychological symptoms of 
madness found in dreams to such a degree that 
the comparison of the two states has become 
a commonplace but insanity appears also to 
have its origin in an exhaustion of the brain, 
which is caused, like normal fatigue, by the 
accumulation of certain specific poisons in the 
elements of the nervous system. 1 We know that 
insanity is often a sequel to infectious diseases, 
and that, moreover, it is possible to reproduce 
experimentally, by toxic drugs, all the phenomena 
of madness. 2 Is it not likely, therefore, that the 
loss of mental equilibrium in the insane is simply 
the result of a disturbance of the sensori-motor 
relations established in the organism ? This 

1 This idea has recently been developed by various authors. 
A systematic account of it will be found in the work of Cowles, 
The Mechanism of Insanity (American Journal of Insanity, 

1 See, in especial, Moreau de Tours, Du haschisch. Paris, 


disturbance may be enough to create a sort of 
psychic vertigo, and so cause memory and atten 
tion to lose contact with reality. If we read the 
descriptions given by some mad patients of the 
beginning of their malady, we find that they often 
feel a sensation of strangeness, or, as they say, 
of unreality/ as if the things they perceived 
had for them lost solidity and relief. 1 If our 
analyses are correct, the concrete feeling that 
we have of present reality consists, in fact, of 
our consciousness of the actual movements where 
by our organism is naturally responding to stimu 
lation ; so that where the connecting links be 
tween sensations and movements are slackened 
or tangled, the sense of the real grows weaker 
or disappears. 2 

There are here, moreover, many distinctions 
to be made, not only between the various forms 
of insanity, but also between insanity properly 
so-called and that division of the personality 
which recent psychology has so ingeniously com 
pared with it. 8 In these diseases of personality it 
seems that groups of recollections detach themselves 
from the central memory and forego their solid 
arity with the others. But, then, it seldom occurs 
that the patient does not also display accompany- 

1 Ball, Legons sur les maladies mentales. Paris, 1890, p. 608 
et seq. Cf . a curious analysis : Visions, a Personal Narrative, 
Journal of Mental Science (1896, p. 284). 

2 See above, p. 176. 

1 Pierre Janet, Les accidents mentaux. Paris, 1894, p. 292 
et seq. 


ing scissions of sensibility and of motor activity. 1 
We cannot help seeing in these latter phenomena 
the real material substratum of the former. If 
it be true that our intellectual life rests, as a whole, 
upon its apex, that is to say upon the sensori-motor 
functions by which it inserts itself into present 
reality, intellectual equilibrium will be differently 
affected as these functions are damaged in one 
manner or in another. Now, besides the lesions 
which affect the general vitality of the sensori- 
motor functions, weakening or destroying what 
we have called the sense of reality, there are others 
which reveal themselves in a mechanical, not a 
dynamical, diminution of these functions, as if 
certain sensori-motor connexions merely parted 
company with the rest. If we are right in our 
hypothesis, memory is ver^ differently affected 
in the two cases. In the first, no recollection is 
taken away, but all recollections are less ballasted, 
less solidly directed towards the real ; whence 
arises a true disturbance of the mental equili 
brium. In the second, the equilibrium is not 
destroyed, but it loses something of its com 
plexity. Recollections retain their normal as 
pect, but forego a part of their solidarity, because 
their sensori-motor base, instead of being, so 
to speak, chemically changed, is mechanically 
diminished. But neither in the one case nor in 
the other are memories directly attacked or 

1 Pierre Janet, L automalisnte psychologique. Paris, 1898, 
p. 95 et seq. 


The idea that the body preserves memories in 

the mechanical form of cerebral deposits, that the 

loss or decrease of memory consists in 

Injuries to the . , , i 

brain affect the their more or less complete destruction, 

motor prolon- ..,,... / j t_ i 

gations through that the heightening of memory and hal- 

which memo- .... . , 

ries are actual- lucmation consists, on the contrary, in 

ized, or the ... ... 

ensori-motor an excess of their activity, is not, then, 

equilibrium , . 

which condi- borne out either by reasoning or by facts. 

tions our , . 

attention The truth is that there is one case, and 
cannot destroy one only, in which observation would 

memories. - , . 

seem at first to suggest this view : we 
mean aphasia, or, more generally, the disturb 
ance of auditory or visual recognition. This is 
the only case in which the constant seat of the 
disorder is in a determined convolution of the 
brain ; but it is also precisely the case in which 
we do not find a mechanical, immediate and 
final destruction of certain definite recollections, 
but rather the gradual and functional weakening of 
the whole of the affected memory. And we have 
explained how the cerebral lesion may effect this 
weakening, without the necessity of supposing any 
sort of provision of memories stored in the brain. 
What the injury really attacks are the sensory and 
motor regions corresponding to this class of percep 
tion, and especially those adjuncts through which 
they may be set in motion from within ; so that 
memory, finding nothing to catch hold of, ends by 
becoming practically powerless: now, in psychology, 
powerlessness means unconsciousness. In all other 
cases, the lesion observed or supposed, never defi- 


nitely localized, acts by the disturbance which it 
causes to the whole of the sensori-motor con 
nexions, either by damaging or by breaking up 
this mass : whence results a breach or a simplifying 
of the intellectual equilibrium, and, by ricochet, 
the disorder or the disjunction of memory. The 
doctrine which makes of memory an immediate 
function of the brain a doctrine which raises 
insoluble theoretical difficulties a doctrine the 
complexity of which defies all imagination, and the 
results of which are incompatible with the data 
of introspection cannot even count upon the sup 
port of cerebral pathology. All the facts and all 
the analogies are in favour of a theory which 
regards the brain as only an intermediary between 
sensation and movement, which sees in this 
aggregate of sensations and movements the pointed 
end of mental life a point ever pressed forward 
into the tissue of events, and, attributing thus to the 
body the sole function of directing memory to 
wards the real and of binding it to the present, 
considers memory itself as absolutely independent 
of matter. In this sense, the brain contributes to 
the recall of the useful recollection, but still more 
to the provisional banishment of all the others. 
We cannot see how memory could settle within 
matter ; but we do clearly understand how 
according to the profound saying of a contempor 
ary philosopher materiality begets oblivion 1 

1 Ravaisson, La philosophic en France au xix? si&cle, 3rd 
edit., p. 176. 



ONE general conclusion follows from the first 
three chapters of this book : it is that the body, 
always turned towards action, has for its 
mmtanaw essential function to limit, with a view 
clnlfe Ts~ to action, the life of the spirit. In regard 
&> e nof enta ~ to representations it is an instrument of 
fowa C rd S asne8S choice, and of choice alone. It can 
neither beget nor cause an intellectual 
state. Consider perception, to begin with. The 
body, by the place which at each moment it occupies 
in the universe, indicates the parts and the aspects 
of matter on which we can lay hold : our percep 
tion, which exactly measures our virtual action on 
things, thus limits itself to the objects which ac 
tually influence our organs and prepare our move 
ments. Now let us turn to memory. The function 
of the body is not to store up recollections, but 
simply to choose, in order to bring back to distinct 
consciousness, by the real efficacy thus conferred 
on it, the useful memory, that which may com 
plete and illuminate the present situation with a 



view to ultimate act ion. It is true that this second 
choice is much less strictly determined than the 
first, because our past experience is an individual and 
no longer a common experience, because we have 
always many different recollections equally capable 
of squaring with the same actual situation, and 
because nature cannot here, as in the case of per 
ception, have one inflexible rule for delimiting our 
representations. A certain margin is, therefore, 
necessarily left in this case to fancy ; and though 
animals scarcely profit by it, bound as they are to 
material needs, it would seem that the human mind 
ceaselessly presses with the totality of its memory 
against the door which the body may half open 
to it : hence the play of fancy and the work of 
imagination so many liberties which the mind 
takes with nature. It is none the less true that 
the orientation of our consciousness towards action 
appears to be the fundamental law of our psychi 
cal life. 

Strictly, we might stop here, for this work was 
undertaken to define the function of the body in 
the life of the spirit. But, on the one hand, we 
have raised by the way a metaphysical problem 
which we cannot bring ourselves to leave in sus 
pense ; and on the other, our researches, although 
mainly psychological, have on several occasions 
given us glimpses, if not of the means of solving 
the problem, at any rate of the side on which it 
should be approached. 

This problem is no less than that of the union of 


soul and body. It comes before us clearly and 
A true with urgency , because we make a profound 
psychology, distinction between matter and spirit. 


between And we cannot regard it as insoluble, 

spirit and 

matter, yet since we define spirit and matter by 

suggests the J 

manner of positive characters, and not by nega- 

their union. r J 

tions. It is in very truth within matter 
that pure perception places us, and it is really into 
spirit that we penetrate by means of memory. 
But on the other hand, whilst introspection reveals 
to us the distinction between matter and spirit, 
it also bears witness to their union. Either, 
then, our analyses are vitiated db origine, or they 
must help us to issue from the difficulties that 
they raise. 

The obscurity of this problem, in all doctrines, 
is due to the double antithesis which our under- 

standing establishes between the ex- 

the S doubie tended and the unextended on the one 

between quality and quantity on 
other. It is certain that mind, first 
^> stands over against matter as a 

Sw a perceived P ure um ty m * ace ^ an essentially 
universe. divisible multiplicity ; and moreover 
that our perceptions are composed of heterogene 
ous qualities, whereas the perceived universe 
seems to resolve itself into homogeneous and cal 
culable changes. There would thus be inexten- 
sion and quality on the one hand, extensity 
and quantity on the other. We have repu 
diated materialism, which derives the first term 


from the second ; but neither do we accept 
idealism, which holds that the second is con 
structed by the first. We maintain, as against 
materialism, that perception overflows infi 
nitely the cerebral state ; but we have en 
deavoured to establish, as against idealism, 
that matter goes in every direction beyond our 
representation of it, a representation which the 
mind has gathered out of it, so to speak, by 
an intelligent choice. Of these two opposite 
doctrines, the one attributes to the body and the 
other to the intellect a true power of creation, the 
first insisting that our brain begets representation 
and the second that our understanding designs the 
plan of nature. And against these two doctrines 
we invoke the same testimony, that of conscious 
ness, which shows us our body as one image 
among others and our understanding as a certain 
faculty of dissociating, of distinguishing, of oppos 
ing logically, but not of creating or of construct 
ing. Thus, willing captives of psychological 
analysis and consequently of common sense, it 
would seem that, after having exacerbated the 
conflicts raised by ordinary dualism, we have 
closed all the avenues of escape which metaphysic 
might set open to us. 

But, just because we have pushed dualism to an 
extreme, our analysis has perhaps dissociated its 
contradictory elements. The theory of pure per 
ception on the one hand, of pure memory on the 
other, may thus prepare the way for a reconcili- 


ation between the unextended and the extended, 
between quality and quantity. 

To take pure perception first. When we make 

the cerebral state the beginning of an action, and in 

no sense the condition of a perception, 

Bat since 

pare percep- W e place the perceived images of things 
of things, these outside the image of our body, and 

share in the J 

natore oi _ thus replace perception within the things 
me idea of themselves. But then, our perception 

extension. f 

being a part of things, things participate 
in the nature of our perception. Material ex- 
tensity is not, cannot any longer be, that compo 
site extensity which is considered in geometry ; 
it indeed resembles rather the undivided exten 
sion of our own representation. That is to say 
that the analysis of pure perception allows us to 
foreshadow in the idea of extension the possible 
approach to each other of the extended and 
the unextended. 

But our conception of pure memory should 
lead us, by a parallel road, to attenuate the second 
And the opposition, that of quality and quantity. 
of et s e e r nffi ity For we have radically separated pure 
recollection from the cerebral state 
in which continues it and renders it efnca- 
: tb * cious. Memory is, then, in no degree an 
tension. emanation of matter ; on the contrary, 
matter, as grasped in concrete perception which 
always occupies a certain duration, is in great 
part the work of memory. Now where is, pre 
cisely, the difference between the heterogeneous 


qualities which succeed each other in our con 
crete perception and the homogeneous changes 
which science puts at the back of these perceptions 
in space ? The first are discontinuous and can 
not be deduced one from another ; the second, 
on the contrary, lend themselves to calculation. 
But, in order that they may lend themselves to 
calculation, there is no need to make them into 
pure quantities : we might as well say that they 
are nothing at all. It is enough that their hetero 
geneity should be, so to speak, sufficiently diluted 
to become, from our point of view, practically 
negligible. Now, if every concrete perception, 
however short we suppose it, is already a 
synthesis, made by memory, of an infinity of 
pure perceptions which succeed each other, 
must we not think that the heterogeneity of 
sensible qualities is due to their being contracted 
in our memory, and the relative homogeneity 
of objective changes to the slackness of their 
natural tension ? And might not the interval 
between quantity and quality be lessened by 
considerations of tension, as the distance be 
tween the extended and the uriextended is les 
sened by considerations of extension ? 

Before entering on this question, let us formu 
late the general principle of the method we would 
apply. We have already made use of it hi an 
earlier work and even, by implication, in the 
present essay. 

That which is commonly called a fact is not 


reality as it appears to immediate intuition, but 
The method of an adaptation of the real to the interests 

philosophy. / , j .- . 

objects and oi practice and to the exigencies of 
have S been social life. Pure intuition, external or 

a pMi- internal, is that of an undivided con- 
tinuity. We break up this continuity 
reah-ty itself. into e i emen ts laid side by side, which 

correspond in the one case to distinct words, 
in the other to independent objects. But, just 
because we have thus broken the unity of our 
original intuition, we feel ourselves obliged to 
establish between the severed terms a bond which 
can only then be external and superadded. For 
the living unity, which was one with internal 
continuity, we substitute the factitious unity 
of an empty diagram as lifeless as the parts 
which it holds together. Empiricism and dog 
matism are, at bottom, agreed in starting from 
phenomena so reconstructed ; they differ only in 
that dogmatism attaches itself more particularly 
to the form and empiricism to the matter. Em 
piricism, feeling indeed, but feeling vaguely, the 
artificial character of the relations which unite 
the terms together, holds to the terms and 
neglects the relations. Its error is not that 
it sets too high a value on experience, but 
that it substitutes for true experience, that ex 
perience which arises from the immediate contact 
of the mind with its object, an experience which is 
disarticulated and therefore, most probably, dis 
figured, at any rate arranged for the greater 


facility of action and of language. Just because 
this parcelling of the real has been effected in view 
of the exigencies of practical life, it has not followed 
the internal lines of the structure of things : for 
that very reason empiricism cannot satisfy the 
mind in regard to any of the great problems and, 
indeed, whenever it becomes fully conscious of its 
own principle, it refrains from putting them. 
Dogmatism discovers and disengages the diffi 
culties to which empiricism is blind ; but it really 
seeks the solution along the very road that 
empiricism has marked out. It accepts, at the 
hands of empiricism, phenomena that are separate 
and discontinuous, and simply endeavours to effect 
a synthesis of them which, not having been given 
by intuition, cannot but be arbitrary. In other 
words, if metaphysic is only a construction, there 
are several systems of metaphysic equally plau 
sible, which consequently refute each other, 
and the last word must remain with a critical 
philosophy, which holds all knowledge to be re 
lative and the ultimate nature of things to be 
inaccessible to the mind. Such is, in truth, the 
ordinary course of philosophic thought : we start 
from what we take to be experience, we attempt 
various possible arrangements of the fragments 
which apparently compose it, and when at last we 
feel bound to acknowledge the fragility of every 
edifice that we have built, we end by giving 
up all effort to build. But there is a last enter 
prise that might be undertaken. It would be to 


seek experience at its source, or rather above that 
decisive turn where, taking a bias in the direction 
of our utility, it becomes properly human experi 
ence. The impotence of speculative reason, as 
Kant has demonstrated it, is perhaps at bottom 
only the impotence of an intellect enslaved to 
certain necessities of bodily life, and concerned 
with a matter which man has had to disorganize 
for the satisfaction of his wants. Our knowledge of 
things would thus no longer be relative to the 
fundamental structure of our mind, but only to its 
superficial and acquired habits, to the contingent 
form which it derives from our bodily functions 
and from our lower needs. The relativity of 
knowledge may not, then, be definitive. By 
unmaking that which these needs have made, we 
may restore to intuition its original purity and 
so recover contact with the real. 

This method presents, in its application, diffi 
culties which are considerable and ever recurrent, 
because it demands for the solution of each new 
problem an entirely new effort. To give up certain 
habits of thinking, and even of perceiving, is far 
from easy : yet this is but the negative part of the 
work to be done ; and when it is done, when we 
have placed ourselves at what we have called the 
turn of experience, when we have profited by the 
faint light which, illuminating the passage from 
the immediate to the useful, marks the dawn of our 
human experience, there still remains to be recon 
stituted, with the infinitely small elements which 


we thus perceive of the real curve, the curve itself 
stretching out into the darkness behind them. 
In this sense the task of the philosopher, as we 
understand it, closely resembles that of the mathe 
matician who determines a function by starting 
from the differential. The final effort of philo 
sophical research is a true work of integration. 

We have already attempted to apply this 
method to the problem of consciousness j 1 and it 
appeared to us that the utilitarian work of the mind, 
in what concerns the perception of our inner life, 
consisted in a sort of refracting of pure duration 
into space, a refracting which permits us to separate 
our psychical states, to reduce them to a more 
and more impersonal form and to impose names 
upon them, in short, to make them enter the cur 
rent of social life. Empiricism and dogmatism 
take interior states in this discontinuous 
cism and form ; the first confining itself to the 


alike take states themselves, so that it can see in 


in a discon- the self only a succession of juxtaposed 

tinnous form, 

ignoring facts ; the other grasping the necessity 

duration. vn j u i. j 

of a bond, but unable to find this bond 
anywhere except in a form or in a force, an 
exterior form into which the aggregate is inserted, 
an indetermined and so to speak physical force 
which assures the cohesion of the elements. Hence 
the two opposing points of view as to the question 

1 Time and Free Will, H. Bergson. Published by Sonnen- 
schein & Co. Translation of Les donnees immtdiates de la 


of freedom : for determinism the act is the result 
ant of a mechanical composition of the elements ; 
for the adversaries of that doctrine, if they adhered 
strictly to their principle, the free decision would 
be an arbitrary fiat, a true creation ex nihilo. 
It seemed to us that a third course lay open. This 
is to replace ourselves in pure duration, of which 
the flow is continuous and in which we pass insensi 
bly from one state to another : a continuity which 
is really lived, but artincally decomposed for the 
greater convenience of customary knowledge. 
Then, it seemed to us, we saw the action issue from 
its antecedents by an evolution sui generis, in such 
a way that we find in this action the antecedents 
which explain it, while it yet adds to these some 
thing entirely new, being an advance upon them 
such as the fruit is upon the flower. Freedom is 
not hereby, as has been asserted, reduced to sen 
sible spontaneity. At most this would be the 
case in the animal, of which the psychical life is 
mainly affective. But in man, the thinking being, 
the free act may be termed a synthesis of feelings 
and ideas, and the evolution which leads to it a 
reasonable evolution. The artifice of this method 
simply consists, in short, in distinguishing the 
point of view of customary or useful knowledge 
from that of true knowledge. The duration 
wherein we see ourselves acting, and in which it is 
useful that we should see ourselves, is a duration 
whose elements are dissociated and juxtaposed. 
The duration wherein we act is a duration wherein 


our states melt into each other. It is within this 
that we should try to replace ourselves by 
thought, in the exceptional and unique case when 
we speculate on the intimate nature of action, that 
is to say, when we are discussing human freedom. 
Is a method of this kind applicable to the prob 
lem of matter ? The question is, whether, in this 
diversity of phenomena of which Kant spoke, 
that part which shows a vague tendency to 
wards extension could be seized by us on the 
hither side of the homogeneous space to which 
it is applied and through which we subdivide it, 
just as that part which goes to make up our 
own inner life can be detached from time, 
equally ignore empty and indefinite, and brought back 

that extension, , ~ . . . . 

concrete and to pure duration. Certainly it would 
beneath which be a chimerical enterprise to try to free 
an artificial ourselves from the fundamental con 
ditions of external perception. But the 
question is whether certain conditions, which 
we usually regard as fundamental, do not rather 
concern the use to be made of things, the 
practical advantage to be drawn from them, far 
more than the pure knowledge which we can have 
of them. More particularly, in regard to concrete 
extension, continuous, diversified and at the same 
time organized, we do not see why it should be 
bound up with the amorphous and inert space 
which subtends it a space which we divide in 
definitely, out of which we carve figures arbitrar 
ily, and in which movement itself, as we have 


said elsewhere, can only appear as a multiplicity of 
instantaneous positions, since nothing there can 
ensure the coherence of past with present. It 
might, then, be possible, in a certain measure, to 
transcend space without stepping out from 
extensity ; and here we should really have a 
return to the immediate, since we do indeed per 
ceive extensity, whereas space is merely conceived, 
being a kind of mental diagram. It may be urged 
against this method that it arbitrarily attri 
butes a privileged value to immediate know 
ledge ? But what reasons should we have for 
doubting any knowledge, would the idea of doubt 
ing it ever occur to us, but for the difficulties 
and the contradictions which reflexion discovers, 
but for the problems which philosophy poses ? 
And would not immediate knowledge find in itself 
its justification and proof, if we could show that 
these difficulties, contradictions and problems 
are mainly the result of the symbolic diagrams 
which cover it up, diagrams which have for us 
become reality itself, and beyond which only an 
intense and unusual effort can succeed in pene 
trating ? 

Let us choose at once, among the results to 
which the application of this method may lead, 
those which concern our present enquiry. We 
must confine ourselves to mere suggestions ; 
there can be no question here of constructing a 
theory of matter. 


I. Every movement, inasmuch as it is a passage 
from rest to rest, is absolutely indivisible. 

This is not an hypothesis, but a fact, generally 
masked by an hypothesis. 

Here, for example, is my hand, placed at the 
point A. I carry it to the point B, passing at one 
stroke through the interval between them. There 
are two things in this movement : an image which 
I see, and an act of which my muscular sense 
makes my consciousness aware. My consciousness 
gives me the [inward feeling of a single fact, 
for in A was rest, in B there is again rest, and 
between A and B is placed an indivisible or at 
least an undivided act, the passage from rest to 
Movement res * which is movement itself. But 
IM^MUS m y sight perceives the movement in 
trajectory oi the form of a line AB which is traversed, 
bo?ythaf is 3Ln ^ *^ s ^ me ^ e ^ space, may be 
divisible. indefinitely divided. It seems then, at 

first sight, that I may at will take this move 
ment to be multiple or indivisible, according as 
I consider it in space or in time, as an image which 
takes shape outside of me or as an act which I 
am myself accomplishing. 

Yet, when I put aside all preconceived ideas, 
I soon perceive that I have no such choice, that 
even my sight takes in the movement from A to B 
as an indivisible whole, and that if it divides any 
thing, it is the line supposed to have been traversed, 
and not the movement traversing it. It is indeed 


true that my hand does not go from A to B with 
out passing through the intermediate positions, 
and that these intermediate points resemble 
stages, as numerous as you please, all along the 
route ; but there is, between the divisions so 
marked out and stages properly so called, this 
capital difference, that at a stage we halt, where 
as at these points the moving body passes. Now 
a passage is a movement and a halt is an immo 
bility. The halt interrupts the movement ; the pas 
sage is one with the movement itself. When I see 
the moving body pass any point, I conceive, no 
doubt, that it might stop there ; and even when 
it does not stop there, I incline to consider its 
passage as an arrest, though infinitely short, 
because I must have at least the time to think 
of it ; but it is only my imagination which stops 
there, and what the moving body has to do is, on 
the contrary, to move. As every point of space 
necessarily appears to me fixed, I find it ex 
tremely difficult not to attribute to the moving 
body itself the immobility of the point with 
which, for a moment, I make it coincide ; it 
seems to me, then, when I reconstitute the total 
movement, that the moving body has stayed an 
infinitely short time at every point of its trajec 
tory. But we must not confound the data of the 
senses, which perceive the movement, with the 
artifice of the mind, which recomposes it. The 
senses, left to themselves, present to us the real 
movement, between two real halts, as a solid 


and undivided whole. The division is the work 
of our imagination, of which indeed the office is 
to fix the moving images of our ordinary experi 
ence, like the instantaneous flash which illumin 
ates a stormy landscape by night. 

We discover here, at its outset, the illusion which 
accompanies and masks the perception of real 
movement. Movement visibly consists in passing 
from one point to another, and consequently in 
traversing space. Now the space which is tra 
versed is infinitely divisible ; and as the move 
ment is, so to speak, applied to the line along 
which it passes, it appears to be one with this 
line and, like it, divisible. Has not the move 
ment itself drawn the line ? Has it not traversed 
in turn the successive and juxtaposed points of 
that line ? Yes, no doubt, but these points have 
no reality except in a line drawn, that is to say 
motionless ; and by the very fact that you 
represent the movement to yourself successively 
in these different points, you necessarily arrest 
it in each of them ; your successive positions 
are, at bottom, only so many imaginary halts. 
You substitute the path for the journey, and 
because the journey is subtended by the path 
you think that the two coincide. But how 
should a progress coincide with a thing, a move 
ment with an immobility ? 

What facilitates this illusion is that we dis 
tinguish moments in the course of duration, like 
halts in the passage of the moving body. Even 


if we grant that the movement from one point to 
another forms an undivided whole, this move 
ment nevertheless takes a certain time ; so that 
if we carve out of this duration an indivisible 
instant, it seems that the moving body must oc 
cupy, at that precise moment, a certain position, 
which thus stands out from the whole. The indi 
visibility of motion implies, then, the impossibil 
ity of real instants ; and indeed, a very brief 
analysis of the idea of duration will show us both 
why we attribute instants to duration and why 
it cannot have any. Suppose a simple movement 
like that of my hand when it goes from A to B. 
This passage is given to my consciousness as 
an undivided whole. No doubt it endures ; but 
this duration, which in fact coincides with the 
aspect which the movement has inwardly 
for my consciousness, is, like it, whole and 
undivided. Now, while it presents itself, qua 
movement, as a simple fact, it describes in space 
a trajectory which I may consider, for purposes 
of simplification, as a geometrical line ; and the 
extremities of this line, considered as abstract 
limits, are no longer lines, but indivisible points. 
Now, if the line, which the moving body has 
described, measures for me the duration of its 
movement, must not the point, where the line 
ends, symbolize for me a terminus of this dura 
tion ? And if this point is an indivisible of length, 
how shall we avoid terminating the duration of 
the movement by an indivisible of duration ? If 


the total line represents the total duration, the parts 
of the line must, it seems, correspond to parts 
of the duration, and the points of the line to 
moments of time. The indivisibles of duration, 
or moments of time, are born, then, of the need 
of symmetry ; we come to them naturally as 
soon as we demand from space an integral pre 
sentment of duration. But herein, precisely, lies 
the error. While the line AB symbolizes the 
duration already lapsed of the movement from A 
to B already accomplished, it cannot, motion 
less, represent the movement in its accomplish 
ment nor duration in its flow. And from 
the fact that this line is divisible into parts 
and that it ends in points, we cannot conclude 
either that the corresponding duration is com 
posed of separate parts or that it is limited by 

The arguments of Zeno of Elea have no other 
origin than this illusion. They all consist in 
zeno trans- making time and movement coincide 

fers to the 

moving body with the line which underlies them, in 

the proper 
ties oi its attributing to them the same sub- 
trajectory : . . t , . 
hence aii the divisions as to the line, in short in 

difficulties and 

contradictions treating them like that line. In this 
confusion Zeno was encouraged by common 
sense, which usually carries over to the movement 
the properties of its trajectory, and also - by 
language, which always translates movement 
and duration in terms of space. But common 
sense and language have a right to do so 


and are even bound to do so, for, since they 
always regard the becoming as a thing to be 
made use of, they have no more concern with 
the interior organization of movement than 
a workman has with the molecular structure of 
his tools. In holding movement to be divisible, 
as its trajectory is, common sense merely expresses 
the two facts which alone are of importance in 
practical life: first, that every movement de 
scribes a space ; second, that at every point of 
this space the moving body might stop. But the 
philosopher who reasons upon the inner nature 
of movement is bound to restore to it the mobility 
which is its essence, and this is what Zeno omits 
to do. By the first argument (the Dichotomy) 
he supposes the moving body to be at rest, and 
then considers nothing but the stages, infinite in 
number, that are along the line to be traversed : 
we cannot imagine, he says, how the body could 
ever get through the interval between them. 
But in this way he merely proves that it is 
impossible to construct, d priori, movement with 
immobilities, a thing no man ever doubted. 
The sole question is whether, movement being 
posited as a fact, there is a sort of retrospective 
absurdity in assuming that an infinite number 
of points has been passed through. But at 
this we need not wonder, since movement is an 
undivided fact, or a series of undivided facts, 
whereas the trajectory is infinitely divisible. In 
the second argument (the Achilles) movement is 


indeed given, it is even attributed to two moving 
bodies, but, always by the same error, there is 
an assumption that their movement coincides 
with their path, and that we may divide 
it, like the path itself, in any way we please. 
Then, instead of recognizing that the tortoise 
has the pace of a tortoise and Achilles the pace 
of Achilles, so that after a certain number of these 
indivisible acts or bounds Achilles will have 
outrun the tortoise, the contention is that we 
may disarticulate as we will the movement of 
Achilles and, as we will also, the movement of the 
tortoise : thus reconstructing both in an arbi 
trary .way, according to a law of our own which 
may be incompatible with the real conditions 
of mobility. The same fallacy appears, yet 
more evident, in the third argument (the Arrow) 
which consists in the conclusion that, because 
it is possible to distinguish points on the path 
of a moving body, we have the right to distinguish 
indivisible moments in the duration of its move 
ment. But the most instructive of Zeno s argu 
ments is perhaps the fourth (the Stadium) which 
has, we believe, been unjustly disdained, and of 
which the absurdity is more manifest only because 
the postulate masked in the three others is here 
frankly displayed. 1 Without entering on a dis- 

1 We may here briefly recall this argument. Let there 
be a moving body which is displaced with a certain velocity, 
and which passes simultaneously before two bodies, one at 
rest and the other moving towards it with the same velocity 


cussion which would here be out of place, we will 
content ourselves with observing that motion, as 
given to spontaneous perception, is a fact which is 
quite clear, and that the difficulties and contra 
dictions pointed out by the Eleatic school concern 
far less the living movement itself than a dead 
and artificial reorganization of movement by the 
mind. But we now come to the conclusion of all 
the preceding paragraphs : 

as its own. During the same time that it passes a certain 
length of the first body, it naturally passes double that length 
of the other. Whence Zeno concludes that a duration is 
the double of itself. A childish argument, it is said, because 
Zeno takes no account of the fact that the velocity is in the 
one case double that which it is in the other. Certainly, but 
how, I ask, could he be aware of this ? That, in the same 
time, a moving body passes different lengths of two bodies, 
of which one is at rest and the other in motion, is clear for 
him who makes of duration a kind of absolute, and places 
it either in consciousness or in something which partakes 
of consciousness. For while a determined portion of this 
absolute or conscious duration elapses, the same moving 
body will traverse, as it passes the two bodies, two spaces of 
which the one is the double of the other, without our being 
able to conclude from this that a duration is double itself, 
since duration remains independent of both spaces. But 
Zeno s error, in all his reasoning, is due to just this fact, 
that he leaves real duration on one side, and considers only 
its objective track in space. How then should the two 
lines traced by the same moving body not merit an equal 
consideration, qua measures of duration ? And how should 
they not represent the same duration, even though the one 
is twice the other ? In concluding from this that a duration 
is the double of itself, Zeno was true to the logic of his hypo 
thesis ; and his fourth argument is worth exactly as much 
as the three others. 


//. There are real movements. 
The mathematician, expressing with greater pre 
cision an idea of common sense, defines position 
by the distance from points of reference 

Movement f -, , . , 

is relative or from axes, and movement by the 

only for the ... , ,, ,. . _. . 

mathema- variation of the distance. Of move- 

tician, real , u , -, 

for the ment, then, he only retains changes in 
length ; and as the absolute values of 
the variable distance between a point and an 
axis, for instance, express either the displacement 
of the axis with regard to the point or that 
of the point with regard to the axis, just as we 
please, he attributes indifferently to the same point 
repose or motion. If, then, movement is no 
thing but a change of distance, the same object 
is in motion or motionless according to the 
points to which it is referred, and there is no 
absolute movement. 

But things wear a very different aspect when 
we pass from mathematics to physics, and from 
the abstract study of motion to a consideration 
of the concrete changes occurring in the universe. 
Though we are free to attribute rest or motion 
to any material point taken by itself, it is none 
the less true that the aspect of the material 
universe changes, that the internal configuration 
of every real system varies, and that here we have 
no longer the choice between mobility and rest. 
Movement, whatever its inner nature, becomes 
an indisputable reality. We may not be able 
to say what parts of the whole are in motion ; 


motion there is in the whole, none the less. 
Therefore it is not surprising that the same 
thinkers, who maintain that every particular 
movement is relative, speak oi the totality of 
movements as of an absolute. The contradiction 
has been pointed out in Descartes, who, after hav 
ing given to the thesis of relativity its most radical 
form by affirming that all movement is recip 
rocal, x formulated the laws of motion as though 
motion were an absolute. Leibniz and others 
after him have remarked this contradiction 8 : 
it is due simply to the fact that Descartes handles 
motion as a physicist after having denned it as a 
geometer. For the geometer all movement is 
relative : which signifies only, in our view, that 
none of our mathematical symbols can express the 
fact that it is the moving body which is in motion 
rather than the axes or the points to which it is 
referred. And this is very natural, because 
these symbols, always meant for measurement, 
can express only distances. But that there 
is real motion no one can seriously deny : if 
there were not, nothing in the universe would 
change ; and, above all, there would be no meaning 
in the consciousness which we have of our own 
movements. In his controversy with Descartes 
Henry More makes jesting allusion to this last 

1 Descartes, Principes, ii, 29. 
1 Principes, part ii, 37 et seq. 

* Leibniz, Specimen dynamicum (Mathem. Schriften, 
Gerhardt, 2nd section, vol. ii, p. 246). 


point : When I am quietly seated, and another, 
going a thousand paces away, is flushed with 
fatigue, it is certainly he who moves and I who 
am at rest. l 

But if there is absolute motion, is it possible 

to persist in regarding movement as nothing 

but a change of place ? We should then 

have to make diversity of place into 

any real move- an absolute difference, and distinguish 

ment*. they , , . . -LI 

cannot be absolute positions in an absolute space. 
changes of Newton * went as far as this, followed 
moreover by Euler * and by others. 
But can this be imagined, or even conceived ? 
A place could be absolutely distinguished from 
another place only by its quality or by its rela 
tion to the totality of space : so that space 
would become, on this hypothesis, either com 
posed of heterogeneous parts or finite. But to 
finite space we should give another space as 
boundary, and beneath heterogeneous parts of 
space we should imagine an homogeneous space 
as its foundation : in both cases it is to homogen 
eous and indefinite space that we should neces 
sarily return. We cannot, then, hinder ourselves 
either from holding every place to be relative, 
or from believing some motion to be absolute. 

It may be urged that real movement is dis 
tinguished from relative movement in that it 

1 H. Moms, Scripta PhilosopMca, 1679, vol. ii, p. 248. 
8 Newton, Principia, Ed. Thomson, 1871, p. 6 et seq. 
3 Euler, Theoriumotuscorpor urn solidorum, 1765, pp. 30-33. 


has a real cause, that it emanates from a force. 
But we must understand what we mean by this 
last word. In natural science force is only a 
function of mass and velocity : it is measured 
by acceleration : it is known and estimated only 
by the movements which it is supposed to 
produce in space. One with these movements, 
it shares their relativity. Hence the physicists, 
who seek the principle of absolute motion in force 
so denned, are led by the logic of their system 
back to the hypothesis of an absolute space which 
they had^at first desired to avoid. 1 So it will be 
come necessary to take refuge in the metaphy 
sical sense of the word, and attribute the motion 
which we perceive in space to profound causes, 
analogous to those which our consciousness be 
lieves it discovers within the feeling of effort. 
But is the feeling of effort really the sense of 
a profound cause ? Have not decisive analyses 
shown that there is nothing in this feeling other 
than the consciousness of movements already 
effected or begun at the periphery of the body ? 
It is in vain, then, that we seek to found the 
reality of motion on a cause which is distinct 
from it : analysis always brings us back to 
motion itself. 

But why seek elsewhere ? So long as we apply 
a movement to the line along which it passes, 
the same point will appear to us, by turns, accord 
ing to the points or the axes to which we 

* Newton, in particular. 


refer it, either at rest or in movement. But it 
is otherwise if we draw out of the movement the 
mobility which is its essence. When my eyes give 
me the sensation of a movement, this sensation is 
a reality, and something is effectually going on, 
whether it be that an object is changing its place 
before my eyes or that my eyes are moving 
before the object. A fortiori am I assured of 
the reality of the movement when I produce 
it after having willed to produce it, and my 
muscular sense brings me the consciousness 
of it. That is to say, I grasp the reality of 
movement when it appears to me, within me, as a 
change of state or of quality. But then how should 
it be otherwise when I perceive changes of quality 
in things ? Sound differs absolutely from silence, 
as also one sound from another sound. Between 
light and darkness, between colours, between 
shades, the difference is absolute. The passage 
from one to another is also an absolutely real 
phenomenon. I hold then the two ends of the 
chain, muscular sensations within me, the sensible 
qualities of matter without me, and neither in 
the one case nor in the other do I see movement, 
if there be movement, as a mere relation : it is an 
absolute. Now, between these two extremities lie 
the movements of external bodies, properly so 
called. How are we to distinguish here between real 
and apparent movement ? Of what object, exter 
nally perceived, can it be said that it moves, of 
what other that it remains motionless ? To put 


such a question is to admit that the discontinuity 
established by common sense between objects 
independent of each other, having each its indi 
viduality, comparable to kinds of persons, is a valid 
distinction. For, on the contrary hypothesis, 
the question would no longer be how are pro 
duced in given parts of matter changes of posi 
tion, but how is effected in the whole a change 
of aspect, a change of which we should then have 
to ascertain the nature. Let us then formulate 
at once our third proposition : 

///. All division of matter into independent 
bodies with absolutely determined outlines is an 
artificial division. 

A body, that is, an independent material object, 
presents itself at first to us as a system of qualities 
The division oi m which resistance and colour the data 

of si g ht and touch occupy the centre, 
a11 tne rest bein g> ^ ^ were > suspended 

from them. On the ther hand > the 

we w!Sr if data * si g nt and touch are those which 
most obviously have extension in space, 
an( j ^he essential character of space is 
continuity. There are intervals of silence between 
sounds, for the sense of hearing is not always oc 
cupied ; between odours, between tastes, there are 
gaps, as though the senses of smell and taste only 
functioned accidentally : as soon as we open 
our eyes, on the contrary, the whole field of vision 
takes on colour ; and, since solids are necessarily 
in contact with each other, our touch must follow 


the surface or the edges of objects without ever 
encountering a true interruption. How do we 
parcel out the continuity of material extensity, 
given in primary perception, into bodies of which 
each is supposed to have its substance and in 
dividuality ? No doubt the aspect of this con 
tinuity changes from moment to moment ; but 
why do we not purely and simply realize that 
the whole has changed, as with the turning of 
a kaleidoscope ? Why, in short, do we seek, in the 
mobility of the whole, tracks that are supposed to 
be followed by bodies supposed to be in motion ? 
A moving continuity is given to us, in which every 
thing changes and yet remains : whence comes 
it that we dissociate the two terms, permanence and 
change, and then represent permanence by bodies 
and change by homogeneous movements in space ? 
This is no teaching of immediate intuition ; but 
neither is it a demand of science, for the object 
of science is, on the contrary, to rediscover the 
natural articulations of a universe we have carved 
artificially. _ Nay more, science, as we shall see, 
by an evermore complete demonstration of the 
reciprocal action of all material points upon each 
other, returns, in spite of appearances, to the idea 
of an universal continuity. Science and conscious 
ness are agreed at bottom, provided that we re 
gard consciousness in its most immediate data, 
and science in its remotest aspirations. Whence 
comes then the irresistible tendency to set up a 
material universe that is discontinuous, composed 


of bodies which have clearly defined outlines and 
change their place, that is, their relation with 
each other ? 

Besides consciousness and science, there is life. 
Beneath the principles of speculation, so carefully 
it is the analysed by philosophers, there are ten- 
of e ii^ing? s dencies of which the study has been neg- 
tiiat mark lected, and which are to be explained 
consciousness simply by the necessity of living, that 

distinct . - .. A , , , 

bodies. is, of acting. Already the power con 
ferred on the individual consciousness of mani 
festing itself in acts requires the formation 
of distinct material zones, which correspond re 
spectively to living bodies : in this sense my own 
body and, by analogy with it, all other living 
bodies are those which I have the most right 
to distinguish in the continuity of the universe. 
But this body itself, as soon as it is constituted 
and distinguished, is led by its various needs 
to distinguish and constitute other bodies. In 
the humblest living being nutrition demands 
research, then contact, in short a series of efforts 
which converge towards a centre : this centre is 
just what is made into an object the object 
which will serve as food. Whatever be the 
nature of matter, it may be said that life will 
at once establish in it a primary discontinuity, 
expressing the duality of the need and of that 
which must serve to satisfy it. But the need 
of food is not the only need. Others group 
themselves round it, all having for object the 


conservation of the individual or of the spe 
cies ; and each of them leads us to distin 
guish, besides our own body, bodies inde 
pendent of it which we must seek or avoid. Our 
needs are, then, so many search-lights which, 
directed upon the continuity of sensible qualities, 
single out in it distinct bodies. They cannot 
satisfy themselves except upon the condition that 
they carve out, within this continuity, a body 
which is to be their own, and then delimit 
other bodies with which the first can enter into 
relation, as if with persons. To establish these 
special relations among portions thus carved out 
from sensible reality is just what we call living. 
But if this first subdivision of the real answers 
much less to immediate intuition than to the 
But, to get a fundamental needs of life, are we likely 
fheipJ OBhicml to g ain a nearer knowledge of things by 
we mnrt rejtct Pushing the division yet further ? In this 
?mS ary wa Y we do indeed prolong the vital move- 
?rac5caf y merit ; but we turn our back upon true 
needs. knowledge. That is why the rough and 

ready operation, which consists in decomposing 
the body into parts of the same nature as itself, 
leads us down a blind alley, where we soon feel 
ourselves incapable of conceiving either why 
this division should cease or how it could go 
on ad infinitum. It is nothing, in fact, but the 
ordinary condition of useful action, unsuitably 
transported into the domain of pure know 
ledge. We shall never explain by means of 


particles, whatever these may be, the simple pro 
perties of matter : at most we can thus follow 
out into corpuscles as artificial as the corpus 
the body itself the actions and reactions of this 
body with regard to all the others. This is pre 
cisely the object of chemistry. It studies bodies 
rather than matter ; and so we understand why 
it stops at the atom, which is still endowed with 
the general properties of matter. But the ma 
teriality of the atom dissolves more and more 
under the eyes of the physicist. We have no 
reason, for instance, for representing the atom 
to ourselves as a solid, rather than as liquid or 
gaseous, nor for picturing the reciprocal action of 
atoms by shocks rather than in any other way. 
Why do we think of a solid atom, and why of 
shocks ? Because solids, being the bodies on 
which we clearly have the most hold, are those 
which interest us most in our relations with the 
external world ; and because contact is the only 
means which appears to be at our disposal in 
order to make our body act upon other bodies. 
But very simple experiments show that there is 
never true contact between two neighbouring 
bodies l ; and besides, solidity is far from being 
an absolutely defined state of matter. 8 Solidity 
and shock borrow, then, their apparent clearness 

1 See, on this subject, Clerk- Maxwell, Action at a Distance 
(Scientific Papers, Cambridge, 1890, vol. ii, pp. 313-314). 

z Clerk-Maxwell, Molecular Constitution of Bodies (Scientific 
Papers, vol. ii, p. 618). Van der Waals has shown, on the 
other hand, the continuity of liquid and gaseous states. 


from the habits and necessities of practical life ; 
images of this kind throw no light on the inner 
nature of things. 

Moreover, if there is a truth that science has 
placed beyond dispute, it is that of the reciprocal 
action of all parts of matter upon each other. 
Between the supposed molecules of bodies the 
forces of attraction and repulsion are at work. 
The influence of gravitation extends throughout 
interplanetary space. Something, then, exists be 
tween the atoms. It will be said that this some 
thing is no longer matter, but force. And we 
shall be asked to picture to ourselves, stretched 
between the atoms, threads which will be made 
more and more tenuous, until they are invisi 
ble and even, we are told, immaterial. But 
what purpose can this crude image serve ? 
The preservation of life no doubt requires that 
we should distinguish, in our daily experience, 
between passive things and actions effected by 
these things in space. As it is useful to us to fix 
the seat of the thing at the precise point where we 
might touch it, its palpable outlines become for 
us its real limit, and we then see in its action a 
something, I know not what, which, being altogether 
different, can part company with it. But since a 
theory of matter is an attempt to find the reality 
hidden beneath these customary images which- are 
entirely relative to our needs, from these images 
it must first of all set itself free. And, indeed, we 
see force and matter drawing nearer together the 


more deeply the physicist has penetrated into their 
effects. We see force more and more materialized, 
the atom more and more idealized, the two terms 
converging towards a common limit and the uni 
verse thus recovering its continuity. We may still 
speak of atoms ; the atom may even retain its 
individuality for our mind which isolates it ; but 
the solidity and the inertia of the atom dissolve 
either into movements or into lines of force whose 
reciprocal solidarity brings back to us universal 
continuity. To this conclusion were bound to 
come, though they started from very different 
positions, the two physicists of the last century 
who have most closely investigated the consti 
tution of matter, Lord Kelvin and Faraday. 
For Faraday the atom is a centre of force. He 
means by this that the individuality of the atom 
consists in the mathematical point at which cross, 
radiating throughout space, the indefinite lines 
of force which really constitute it : thus each 
atom occupies the whole space to which gravita 
tion extends and all atoms are interpenetrating. 1 
Lord Kelvin, moving in another order of ideas, 
supposes a perfect, continuous, homogeneous and 
incompressible fluid, filling space : what we term 
an atom he makes into a vortex ring, ever whirl 
ing in this continuity, and owing its properties to 
its circular form, its existence and consequently 

1 Faraday, A Speculation concerning Electric Conduction 
(Philos. Magazine, 3rd series, vol. xxiv). 


its individuality to its motion. 1 But on either 
hypothesis, the nearer we draw to the ultimate 
elements of matter the better we note the van 
ishing of thkt discontinuity which our senses per 
ceived oifcthe surface. Psychological analysis has 
already /revealed to us that this discontinuity 
is relative to our needs : every philosophy of 
nature ends by finding it incompatible with the 
general properties of matter. 

In truth, vortices and lines of force are never, 
to the mind of the physicist, more than convenient 
figures for illustrating his calculations. But philo 
sophy is bound to ask why these symbols are more 
convenient than others, and why they permit of 
further advance. Could we, working with them, 
get back to experience, if the notions to which 
they correspond did not at least point out the 
direction in which we may seek for a representa 
tion of the real ? Now the direction which they 
indicate is obvious ; they show us, pervading 
concrete extensity, modifications, perturbations, 
changes of tension or of energy, and nothing else. 
It is by this, above all, that they tend to unite 
with the purely psychological analysis of motion 
which we considered to begin with, an analysis 
which presented it to us not as a mere change of 
relation between objects to which it was, as it 

1 Thomson, On Vortex Atoms (Proc. of the Roy. Soc. of 
Edin., 1867). An hypothesis of the same nature had been 
put forward by Graham, On the Molecular Mobility of Gases 
(Proc. of the Roy. Soc., 1863, p. 621 et seq.). 


were, an accidental addition, but as a true and, 
in some sort, an independent, reality. Neither 
science nor consciousness, then, is opposed to 
this last proposition : 

IV. Real movement is rather the transference of 
a state than of a thing. 

By formulating these four propositions, we 

have, in reality, only been progressively narrowing 

the interval between the two terms 

So we shall ,.,... -, , 

see real which it IS USUal to ODDOSC to each 

movement as . 

rather other, qualities or sensations, and 

quality than 

quantity, movements. At first sight, the distance 

and, as such, . . 

akin to appears impassable. Qualities are 

consciousness. rf ** 

heterogeneous, movements homogene 
ous. Sensations, essentially indivisible, escape 
measurement ; movements, always divisible, are 
distinguished by calculable differences of direction 
and velocity. We are fain to put qualities, in the 
form of sensations, in consciousness ; while move 
ments are supposed to take place independently 
of us in space. These movements, compounded 
together, we confess, will never yield anything 
but movements ; our consciousness, though in 
capable of coming into touch with them, yet by a 
mysterious process is said to translate them into 
sensations, which afterwards project themselves 
into space and come to overlie, we know not how, 
the movements they translate. Hence two differ 
ent worlds, incapable of communicating otherwise 
than by a miracle, on the one hand that of motion 


in space, on the other that of consciousness with 
sensations. Now, certainly the difference is irre 
ducible (as we have shown in an earlier work *) 
between quality on the one hand and pure quan 
tity on the other. But this is just the question : 
do real movements present merely differences of 
quantity, or are they not quality itself, vibra 
ting, so to speak, internally, and beating time 
for its own existence through an often incal 
culable number of moments ? Motion, as studied 
in mechanics, is but an abstraction or a sym 
bol, a common measure, a common denomina 
tor, permitting the comparison of all real move 
ments with each other ; but these movements, 
regarded in themselves, are indivisibles which 
occupy duration, involve a before and an after, 
and link together the successive moments of time 
by a thread of variable quality which cannot be 
without some likeness to the continuity of our 
own consciousness. May we not conceive, for 
instance, that the irreducibility of two perceived 
colours is due mainly to the narrow duration into 
which are contracted the billions of vibrations 
which they execute in one of our moments ? If 
we could stretch out this duration, that is to say, 
live it at a slower rhythm, should we not, as the 
rhythm slowed down, see these colours pale and 
lengthen into successive impressions, still coloured, 
no doubt, but nearer and nearer to coincidence 

1 H. Bergson, Time and Free Will. Sonnenschein & Co. 


with pure vibrations ? In cases where the rhythm 
of the movement is slow enough to tally with 
the habits of our consciousness, as in the case of 
the deep notes of the musical scale, for instance, 
do we not feel that the quality perceived analyses 
itself into repeated and successive vibrations, 
bound together by an inner continuity ? That 
which usually hinders this mutual approach of 
motion and quality is the acquired habit of attach 
ing movement to elements atoms or what not, 
which interpose their solidity between the move 
ment itself and the quality into which it contracts. 
As our daily experience shows us bodies in motion, 
it appears to us that there ought to be, in order 
to sustain the elementary movements to which 
qualities may be reduced, diminutive bodies or 
corpuscles. Motion becomes then for our imagin 
ation no more than an accident, a series of posi 
tions, a change of relations ; and, as it is a law 
of our representation that in it the stable drives 
away the unstable, the important and central 
element for us becomes the atom, between the 
successive positions of which movement then be 
comes a mere Hnk. But not only has this concep 
tion the inconvenience of merely carrying over to 
the atom all the problems raised by matter ; not only 
does it wrongly set up as an absolute that division 
of matter which, in our view, is hardly anything 
but an outward projection of human needs ; it 
also renders unintelligible the process by which we 
grasp, in perception, at one and the same time, a 


state of our consciousness and a reality independent 
of ourselves. This mixed character of our imme 
diate perception, this appearance of a realized 
contradiction, is the principal theoretical reason 
that we have for believing in an external world 
which does not coincide absolutely with our per 
ception. As it is overlooked in the doctrine that 
regards sensation as entirely heterogeneous with 
movements, of which sensation is then supposed 
to be only a translation into the language of 
consciousness, this doctrine ought, it would seem, 
to confine itself to sensations, which it had indeed 
begun by setting up as the actual data, and 
not add to them movements which, having no 
possible contact with them, are no longer any 
thing but their useless duplicate. Realism, so 
understood, is self-destructive. Indeed, we have 
no choice : if our belief in a more or less homo 
geneous substratum of sensible qualities has any 
ground, this can only be found in an act which 
makes us seize or divine, in quality itself, some 
thing which goes beyond sensation, as if this sensa 
tion itself were pregnant with details suspected yet 
unperceived. Its objectivity that is to say, what 
it contains over and above what it yields up- 
must then consist, as we have foreshadowed, pre 
cisely in the immense multiplicity of the move 
ments which it executes, so to speak, within itself 
as a chrysalis. Motionless on the surface, in its 
very depth it lives and vibrates. 

As a matter of fact, no one represents to himself 


the relation between quantity and quality in any 
whilst in other way. To believe in realities, dis- 
tinct from that which is perceived, is 
above all to recognize that the order 
f our perceptions depends on them 
an( ^ no * on US - There must be, then, 
within the perceptions which fill a 
ou?own f given moment, the reason of what will 
duration. happen in the following moment. And 
mechanism only formulates this belief with more 
precision when it affirms that the states of matter 
can be deduced one from the other. It is true 
that this deduction is possible only if we discover, 
beneath the apparent heterogeneity of sensible 
qualities, homogeneous elements which lend them 
selves to calculation. But, on the other hand, if 
these elements are external to the qualities of 
which they are meant to explain the regular 
order, they can no longer render the service de 
manded of them, because then the qualities must 
be supposed to come to overlie them by a kind of 
miracle, and cannot correspond to them unless we 
bring in some pre-established harmony. So, do 
what we will, we cannot avoid placing those 
movements within these qualities, in the form of 
internal vibrations, and then considering the vibra 
tions as less homogeneous, and the qualities as 
less heterogeneous, than they appear, and lastly 
attributing the difference of aspect in the two 
terms to the necessity which lies upon what may 
be called an endless multiplicity of contracting 


into a duration too narrow to permit of the 
separation of its moments. 

We must insist on this last point, to which we 
have already alluded elsewhere, and which we 
Thr may regard as essential. The duration lived 
by our consciousness is a duration with 
*ts own [determined rhythm, a duration 
very different from the time of the phy- 
nw. sicist, which can store up, in a given in 

terval, as great a number of phenomena as we 
please. In the space of a second, red light, 
the light which has the longest wave-length, 
and of which, consequently, the vibrations are 
the least frequent accomplishes 400 billions of 
successive vibrations. If we would form some 
idea of this number, we should have to separ 
ate the vibrations sufficiently to allow our con 
sciousness to count them, or at least to record 
explicitly their succession ; and we should then 
have to enquire how many days or months or 
years this succession would occupy. Now the 
smallest interval of empty time which we can 
detect equals, according to Exner, ^ of a second ; 
and it is even doubtful whether we can per 
ceive in succession several intervals as short as 
this. Let us admit, however, that we can go on 
doing so indefinitely. Let us imagine, in a word, 
a consciousness which should watch the succession 
of 400 billions of vibrations, each instantaneous, 
and each separated from the next only by the 
sfa of a second necessary to distinguish them. 


A very simple calculation shows that more than 
25,000 years would elapse before the conclusion 
of the operation. Thus the sensation of red light, 
experienced by us in the course of a second, cor 
responds in itself to a succession of phenomena 
which, separately distinguished in our duration 
with the greatest possible economy of time, would 
occupy more than 250 centuries of our history. 
Is this conceivable ? We must distinguish here 
between our own duration and time in general. 
In our duration, the duration which our con 
sciousness perceives, a given interval can only 
contain a limited number of phenomena of which 
we are aware. Do we conceive that this content 
can increase ; and when we speak of an infi 
nitely divisible time, is it our own duration that 
we are thinking of ? 

As long as we are dealing with space, we may 
carry the division as far as we please ; we change 
in no way, thereby, the nature of what is divided. 
This is because space, by definition, is outside us ; 
it is because a part of space appears to us to sub 
sist even when we cease to be concerned with it ; 
so that, even when we leave it undivided, we know 
that it can wait, and that a new effort of our 
imagination may decompose it when we choose. 
As, moreover, it never ceases to be space, it always 
implies juxtaposition and consequently possible 
division. Abstract space is, indeed, at bottom, no 
thing but the mental diagram of infinite divisibility. 
But with duration it is quite otherwise. The parts of 


our duration are one with the successive moments of 
the act which divides it ; if we distinguish in it so 
many instants, so many parts it indeed possesses ; 
and if our consciousness can only distinguish in a 
given interval a definite number of elementary 
acts, if it terminates the division at a given 
point, there also terminates the divisibility. In 
vain does our imagination endeavour to go on, to 
carry division further still, and to quicken, so to 
speak, the circulation of our inner phenomena : 
the very effort by which we are trying to effect 
this further division of our duration lengthens 
that duration by just so much. And yet we 
know that millions of phenomena succeed each 
other while we hardly succeed in counting a few. 
We know this not from physics alone ; the crude 
experience of the senses allows us to divine it ; 
we are dimly aware of successions in nature 
much more rapid than those of our internal states. 
How are we to conceive them, and what is this 
duration of which the capacity goes beyond all 
our imagination ? 

It is not ours, assuredly ; but neither is it that 
homogeneous and impersonal duration, the same 
for everything and for every one, which flows 
onward, indifferent and void, external to all that 
endures. This imaginary homogeneous time is, 
as we have endeavoured to show elsewhere, 1 an 
idol of language, a fiction of which the origin is 

1 H. i^ergson, Time and Free Will. Sonnenschein & Co. 


easy to discover. In reality there is no one 
rhythm of duration ; it is possible to imagine 
many different rhythms which, slower or faster, 
measure the degree of tension or relaxation of 
different kinds of consciousness, and thereby fix 
their respective places in the scale of being. To 
conceive of durations of different tensions is per 
haps both difficult and strange to our mind, be 
cause we have acquired the useful habit of sub 
stituting for the true duration, lived by conscious 
ness, an homogeneous and independent Time ; 
but, in the first place, it is easy, as we have shown, 
to detect the illusion which renders such a 
thought foreign to us, and, secondly, this idea 
has in its favour, at bottom, the tacit agreement 
of our consciousness. Do we not sometimes per 
ceive in ourselves, in sleep, two contemporaneous 
and distinct persons of whom one sleeps a few 
minutes, while the other s dream fills days and 
weeks ? And would not the whole of history be 
contained in a very short time for a conscious 
ness at a higher degree of tension than our own, 
which should watch the development of human 
ity while contracting it, so to speak, into the 
great phases of its evolution ? In short, then, 
to perceive consists in condensing enormous 
periods of an infinitely diluted existence into a 
few more differentiated moments of an intenser 
life, and in thus summing up a very long history. 
To perceive means to immobilize. 

To say this is to say that we seize, in the 


act of perception, something which outruns per- 
Om ception itself, although the material 

ness sc sums"up universe is not essentially different or 
5ho?e periods distinct from the representation which 

we have of it. In one sense, my per- 
ception is indeed truly within me, since 
it contracts into a single moment of my duration 
that which, taken in itself, spreads over an 
incalculable number of moments. But, if you 
abolish my consciousness, the material universe 
subsists exactly as it was ; only, since you have 
removed that particular rhythm of duration 
which was the condition of my action upon things, 
these things draw back into themselves, mark 
as many moments in their own existence as science 
distinguishes in it ; and sensible qualities, with 
out vanishing, are spread and diluted in an in 
comparably more divided duration. Matter thus 
resolves itself into numberless vibrations, all 
linked together in uninterrupted continuity, all 
bound up with each other, and travelling in every 
direction like shivers through an immense body. 
In short, try first to connect together the dis 
continuous objects of daily experience ; then 
resolve the motionless continuity of their qualities 
into vibrations on the spot ; finally fix your at 
tention on these movements, by abstracting from 
the divisible space which underlies them and 
considering only their mobility (that undivided 
act which our consciousness becomes aware of 
in our own movements) : you will thus obtain a 


vision of matter, fatiguing perhaps for your ima 
gination, but pure, and freed from all that the 
exigencies of life compel you to add to it in 
external perception. Now bring back conscious 
ness, and with it the exigencies of life : at long, 
very long, intervals, and by as many leaps over 
enormous periods of the inner history of things, 
quasi-instantaneous views will be taken, views 
which this time are bound to be pictorial, and 
of which the more vivid colours will condense an 
infinity of elementary repetitions and changes. 
In just the same way the multitudinous successive 
positions of a runner are contracted into a single 
symbolic attitude, which our eyes perceive, which 
art reproduces, and which becomes for us all the 
image of a man running. The glance which falls 
at any moment on the things about us only takes 
in the effects of a multiplicity of inner repetitions 
and evolutions, effects which are, for that very 
reason, discontinuous, and into which we bring 
back continuity by the relative movements that 
we attribute to objects in space. The change 
is everywhere, but inward ; we localize it here 
and there, but outwardly ; and thus we consti 
tute bodies which are both stable as to their 
qualities and mobile as to their positions, a mere 
change of place summing up in itself, to our 
eyes, the universal transformation. 

That there are, in a sense, multiple objects, that 
one man is distinct from another man, tree 
from tree, stone from stone, is an indisputable 


fact ; for each of these beings, each of these 
Necessity things, has characteristic properties and 
beni d that ea obeys a determined law of evolution, 
therbythm oi But * ne separation between a thing and 
$ e maTtn" n its environment cannot be absolutely 
fh y atduSon g definite and clear cut ; there is a passage 
JcJSiSr it b y insensible gradations from the one to 
necessity, trig other : the close solidarity which binds 
all the obj ects of the material universe, the perpetu 
ity of their reciprocal actions and reactions, is suffi 
cient to prove that they have not the precise 
limits which we attribute to them. Our per 
ception outlines, so to speak, the form of their 
nucleus ; it terminates them at the point where 
our possible action upon them ceases, where, 
consequently, they cease to interest our needs. 
Such is the primary and the most apparent opera 
tion of the perceiving mind : it marks out divi 
sions in the continuity of the extended, simply 
following the suggestions of our requirement and 
the needs of practical life. But, in order to divide 
the real in this manner, we must first persuade 
ourselves that the real is divisible at will. Conse 
quently we must throw beneath the continuity 
of sensible qualities, that is to say, beneath con 
crete extensity, a network, of which the meshes 
may be altered to any shape whatsoever and 
become as small as we please : this substra 
tum which is merely conceived, this wholly 
ideal diagram of arbitrary and infinite divisi 
bility, is homogeneous space. Now, at the same 


time that our actual and so to speak instan 
taneous perception effects this division of matter 
into independent objects, our memory solidifies 
into sensible qualities the continuous flow of 
things. It prolongs the past into the present, 
because our action will dispose of the future in 
the exact proportion in which our perception, 
enlarged by memory, has contracted the past. 
To reply, to an action received, by an immediate 
reaction which adopts the rhythm of the first 
and continues it in the same duration, to be in 
the present and in a present which is always 
beginning again, this is the fundamental law of 
matter : herein consists necessity. If there are 
actions that are really free, or at least partly in 
determinate, they can only belong to beings able 
to fix, at long intervals, that becoming to which 
their own becoming clings, able to solidify it into 
distinct moments, and so to condense matter and, 
by assimilating it, to digest it into movements 
of reaction which will pass through the meshes 
of natural necessity. The greater or less ten 
sion of their duration, which expresses, at bottom, 
their greater or less intensity of life, thus deter 
mines both the degree of the concentrating power 
of their perception and the measure of their liberty. 
The independence of their action upon surround 
ing matter becomes more and more assured in the 
degree that they free themselves from the par 
ticular rhythm which governs the flow of this 
matter. So that sensible qualities, as they are 


found in our memory-shot perception, are in 
fact the successive moments obtained by a solidi 
fication of the real. But, in order to distinguish 
these moments, and also to bind them together 
by a thread which shall be common alike to our 
own existence and to that of things, we are bound 
to imagine a diagrammatic design of succes 
sion in general, an homogeneous and indifferent 
medium, which is to the flow of matter in the 
sense of length as space is to it in the sense of 
breadth : herein consists homogeneous time. 

Homogeneous space and homogeneous time 
are then neither properties of things nor essential 

Homogeneous COnditi nS f OUr faulty of knowing 

t?me e are d the tnem : they express, in an abstract 
form > the double work of solidification 
and of division which we effect on 
propertfes not ^ ne mov i n g continuity of the real in 
of things. order to obtain there a fulcrum for our 
action, in order to fix within it starting-points 
for our operation, in short, to introduce into 
it real changes. They are the diagrammatic 
design of our eventual action upon matter. 
The first mistake, that which consists in viewing 
this homogeneous time and space as properties of 
things, leads to the insurmountable difficulties 
of metaphysical dogmatism, whether mechan 
istic or dynamistic, dynamism erecting into 
so many absolutes the successive cross-cuts 
which we make in the course of the universe 
as it flows along, and then endeavouring vainly 


to bind them together by a kind of qualitative 
deduction ; mechanism attaching itself rather, in 
any one of these cross-cuts, to the divisions made 
in its breadth, that is to say, to instantaneous 
differences in magnitude and position, and striv 
ing no less vainly to produce, by the variation of 
these differences, the succession of sensible qualities. 
Shall we then seek refuge in the other hypothesis, 
and maintain, with Kant, that space and time are 
forms of our sensibility ? If we do, we shall have 
to look upon matter and spirit as equally unknow 
able. Now, if we compare these two hypotheses, 
we discover in them a common basis : by setting 
up homogeneous time and homogeneous space 
either as realities that are contemplated or as forms 
of contemplation, they both attribute to space 
and time an interest which is speculative rather 
than vital. Hence there is room, between meta 
physical dogmatism on the one hand and critical 
philosophy on the other, for a doctrine which 
regards homogeneous space and time as princi 
ples of division and of solidification introduced 
into the real with a view to action and not with a 
view to knowledge, which attributes to things a 
real duration and a real extensity, and which, 
in the end, sees the source of all difficulty no 
longer in that duration and in that extensity 
(which really belong to things and are directly 
manifest to the mind), but in the homogeneous 
space and time which we stretch out beneath 
them in order to divide the continuous, to fix the 


becoming, and provide our activity with points 
to which it can be applied. 

But erroneous conceptions about sensible quality 

and about space are so deeply rooted in the mind 

that it is important to attack them 

Qualities of , j TTT J.T. 

different from every side. We may say then, 
in extensity, to reveal yet another aspect, that they 

though In . J . J , 

different imply this double postulate, accepted 
equally by realism and by idealism : 
first, that between different kinds of qualities there 
is nothing common ; second, that neither is there 
anything common between extensity and pure 
quality. We maintain, on the contrary, that 
there is something common between qualities of 
different orders, that they all share in extensity, 
though in different degrees, and that it is im 
possible to overlook these two truths without 
entangling in a thousand difficulties the meta- 
physic of matter, the .psychology of perception 
and, more generally, the problem of the relation 
of consciousness with matter. Without insisting 
on these consequences, let us content ourselves 
for the moment with showing, at the bottom of 
the various theories of matter, the two postulates 
which we dispute and the illusion from which 
they proceed. 

The essence of English idealism is to regard 
extensity as a property of tactile perceptions. 
As it sees nothing in sensible qualities but sen 
sations, and in sensations themselves nothing but 
mental states, it finds in the different qualities 


nothing on which to base the parallelism of 
idealism and their phenomena. It is therefore con- 
regard the strained to account for this parallelism 
orders of by a habit which makes the actual per- 

sensation as . . . , . 

discontinuous, ceptions of sight, lor instance, suggest 

and so miss ~ . 0<:> 

the true to us potential sensations of touch. If 

nature of . , .. 

perception, the impressions of two different senses 
resemble each other no more than the words 
of two languages, we shall seek in vain to de 
duce the data of the one from the data of the 
other. They have no common element ; and 
consequently, there is nothing common between 
extensity, which is always tactile, and the data 
of the senses other than that of touch, which 
must then be supposed to be in no way extended. 
But neither can atomistic realism, which locates 
movements in space and sensations in conscious 
ness, discover anything in common between the 
modifications or phenomena of extensity and the 
sensations which correspond to them. Sensations 
are supposed to issue from the modifications as 
a kind of phosphorescence, or, again, to translate 
into the language of the soul the manifestations 
of matter ; but in neither case do they re 
flect, we are told, the image of their causes. No 
doubt they may all be traced to a common origin, 
which is movement in space ; but, just because 
they develop outside of space, they must forego, 
qua sensations, the kinship which binds their 
causes together. In breaking with space they 
break also their connexion with each other ; they 


have nothing in common between them, nor with 

Idealism and realism, then, only differ in that 
the first relegates extensity to tactile perception, 
of which it becomes the exclusive property, 
while the second thrusts extensity yet further 
back, outside of all perception. But the two 
doctrines are agreed in maintaining the discon 
tinuity of the different orders of sensible qualities, 
and also the abrupt transition from that which 
is purely extended to that which is not extended 
at all. Now the principal difficulties which they 
both encounter in the theory of perception arise 
from this common postulate. 

For suppose, to begin with, as Berkeley did, 
that all perception of extensity is to be referred 
to the sense of touch. We may, indeed, if you 
will have it so, deny extension to the data of 
hearing, smell and taste ; but we must at least 
explain the genesis of a visual space that corre 
sponds to tactile space. It is alleged, indeed, that 
sight ends by becoming symbolic of touch, and 
that there is nothing more in the visual per 
ception of the order of things in space than a 
suggestion of tactile perception. But we fail to 
understand how the visual perception of relief, for 
instance, a perception which makes upon us an 
impress sui generis, and indeed indescribable, 
could ever be one with the mere remembrance of 
a sensation of touch. The association of a mem 
ory with a present perception may complicate 


this perception by enriching it with an element 
already known, but it cannot create a new kind 
of impress, a new quality of perception : now 
the visual perception of relief presents an abso 
lutely original character. It may be urged that 
it is possible to give the illusion of relief with a 
plane surface. This only proves that a surface, 
on which the play of light and shadow on an 
object in relief is more or less well imitated, is 
enough to remind us of relief ; but how could 
we be reminded of relief if relief had not been, 
at first, actually perceived? We have already 
said, but we cannot repeat too often, that our 
theories of perception are entirely vitiated by 
the idea that if a certain arrangement produces, 
at a given moment, the illusion of a certain 
perception, it must always have been able to 
produce the perception itself ; as if the very- 
function of memory were not to make the 
complexity of the effect survive the simplifica 
tion of the cause ! Again, it may be urged that 
the retina itself is a plane surface, and that if we 
perceive by sight something that is extended, it 
can only be the image on the retina. But is it 
not true, as we have shown at the beginning of 
this book, that in the visual perception of an 
object the brain, nerves, retina and the object 
itself form a connected whole, a continuous 
process in which the image on the retina is only 
an episode ? By what right, then, do we isolate 
this image to sum up in it the whole of percep- 


tion ? And then, as we have also shown, 1 
how could a surface be perceived as a surface 
otherwise than ,in a space that has recovered 
its three dimensions ? Berkeley, at least, carried 
out his theory to its conclusion ; he denied to 
sight any perception of extensity. But the ob 
jections which we raised only acquire the more 
force from this, since it is impossible to understand 
the spontaneous creation, by a mere association 
of memories, of all that is original in our visual 
perceptions of line, surface and volume, per 
ceptions so distinct that the mathematician does 
not go beyond them and works with a space 
that is purely visual. But we will not insist on 
these various points, nor on the disputable argu 
ments drawn from the observation of those, born 
blind, whose sight has been surgically restored : 
the theory of the acquired perceptions of sight, 
classical since Berkeley s day, does not seem likely 
to resist the multiplied attacks of contemporary 
psychology. 2 Passing over the difficulties of a 
psychological order, we will content ourselves 
with drawing attention to another point, in our 
opinion essential. Suppose for a moment that 

1 Time and Free Will. Sonnenschein & Co., 1910. 

8 See on this subject : Paul Janet, La perception visuelle 
de la distance, Revue philosophique, 1879, vol. vii, p. I et seq. 
William James, Principles of Psychology, vol.ii, chap. xxii. 
Cf. on the subject of the visual perception of extensity : 
Dunan, L espace visuel et I espace tactile (Revue philosophique, 
Feb. and Apr. 1888, Jan. 1889). 


the eye does not, at the outset, give us any informa 
tion as to any of the relations of space. Visual 
form, visual relief, visual distance, then become 
the symbols of tactile perceptions. But how 
is it, then, that this symbolism succeeds ? Here 
are objects which change their shape and move. 
Vision takes note of definite changes which 
touch afterwards verifies. There is, then, in the 
two series, visual and tactile, or in their causes, 
something which makes them correspond one 
to another and ensures the constancy of their 
parallelism. What is the principle of this con 
nexion ? 

For English idealism, it can only be some deus 
ex machina, and we are confronted with a mys 
tery again. For ordinary realism, it is in a space 
distinct from the sensations themselves that the 
principle of the correspondence of sensations 
one with another lies; but this doctrine only 
throws the difficulty further back and even 
aggravates it, for we shall now want to know 
how a system of homogeneous movements 
in space evokes various sensations which have 
no resemblance whatever with them. Just now 
the genesis of visual perception of space by a 
mere association of images appeared to us to 
imply a real creation ex nihilo ; here all the sen 
sations are born of nothing, or at least have no 
resemblance with the movement that occasions 
them. In the main, this second theory differs 
much less from the first than is commonly believed. 


Amorphous space, atoms jostling against each 
other, are only our tactile perceptions made ob 
jective, set apart from all our other perceptions 
on account of the special importance which we 
attribute to them, and made into independent 
realities, thus contrasting with the other sensa 
tions which are then supposed to be only the 
symbols of these. Indeed, in the course of this 
operation, we have emptied these tactile sensa 
tions of a part of their content ; after having 
reduced all other senses to being mere appen 
dages of the sense of touch, touch itself we mu 
tilate, leaving out everything in it that is not 
a mere abstract or diagrammatic design of tac 
tile perception : with this design we then go 
on to construct the external world. Can we 
wonder that between this abstraction on the one 
hand, and sensations on the other, no possible 
link is to be found ? But the truth is that 
space is no more without us than within us, 
and that it does not belong to a privileged 
group of sensations. All sensations partake of 
extensity ; all are more or less deeply rooted in it ; 
and the difficulties of ordinary realism arise from 
the fact that, the kinship of the sensations one 
with another having been extracted and placed 
apart under the form of an indefinite and empty 
space, we no longer see either how these sensations 
can partake of extensity or how they can corre 
spond with each other. 

Contemporary psychology is more and more 


impressed with the idea that all our sensations 
But modem are in some degree extensive. It is 

psychology . . , . , 

has a tendency maintained, not without an appearance 

to regard all . , . 

sensation as of reason, that there is no sensation 
extensive. without cxtensity l or without a feel 
ing of volume. 2 English idealism sought to 
reserve to tactile perception a monopoly of the 
extended, the other senses dealing with space only 
in so far as they remind us of the data of touch. 
A more attentive psychology reveals to us, on 
the contrary, and no doubt will hereafter reveal 
still more clearly, the need of regarding all sensa 
tions as primarily extensive, their extensity fading 
and disappearing before the higher intensity and 
usefulness of tactile, and also, no doubt, of visual, 

So understood, space is indeed the symbol 
of fixity and of infinite divisibility. Concrete 
we invert extensity, that is to say the diversity of 
wewlaSSst sensible qualities, is not within space ; 
interior*"! rather is it space that we thrust into 
S?he neoe extensity . Space is not a ground on which 
St to tece " rea l motion is posited ; rather is it real 
movements. mo ti O n that deposits space beneath it 
self. But our imagination, which is preoccu- 

1 Ward, Article Psychology in the Encycl. Britannica. 

2 W. James, Principles of Psychology, vol. ii, p. 134 et seq. 
We may note in passing that we might, in strictness, attribute 
this opinion to Kant, since The Transcendental /Esthetic allows 
no difference between the data of the different senses as far 
as their extension in space is concerned. But it must not be 
forgotten that the point of view of the Critique is other than 



pied above all by the convenience of expression 
and the exigencies of material life, prefers to 
invert the natural order of the terms. Accus 
tomed to seek its fulcrum in a world of ready- 
made motionless images, of which the apparent 
fixity is hardly anything else but the outward 
reflexion of the stability of our lower needs, it 
cannot help believing that rest is anterior to 
motion, cannot avoid taking rest as its point 
of reference and its abiding place, so that it 
comes to see movement as only a variation of 
distance, space being thus supposed to precede 
motion. Then, in a space which is homo 
geneous and infinitely divisible, we draw, in 
imagination, a trajectory and fix positions : after 
wards, applying the movement to the trajectory, 
we see it divisible like the line we have drawn, 
and equally denuded of quality. Can we wonder 
that our understanding, working thenceforward 
on this idea, which represents precisely the reverse 
of the truth, discovers in it nothing but contra 
dictions ? Having assimilated movements to space, 
we find these movements homogeneous like space ; 
and since we no longer see in them anything but 
calculable differences of direction and velocity, all 
relation between movement and quality is for us 
destroyed. So that all we have to do is to shut up 
motion in space, qualities in consciousness, and 

that of psychology, and that it is enough for its purpose that 
all our sensations should end by being localized in space 
when perception has reached its final form. 


to establish between these two parallel series, 
incapable, by hypothesis, of ever meeting, a 
mysterious correspondence. Thrown back into 
consciousness, sensible qualities become incap 
able of recovering extensity. , Relegated to space, 
and indeed to abstract space, where there is 
never but a single instant and where everything 
is always being born anew movement aban 
dons that solidarity of the present with the past 
which is its very essence. And as these two 
aspects of perception, quality and movement, 
have been made equally obscure, the phenomenon 
of perception, in which a consciousness, assumed 
to be shut up in itself and foreign to space, is 
supposed to translate what occurs in space, be 
comes a mystery. But let us, on the contrary, 
banish all preconceived idea of interpreting or 
measuring, let us place ourselves face to face 
with immediate reality: at once we find that 
there is no impassable barrier, no essential differ 
ence, no real distinction even, between percep 
tion and the thing perceived, between quality 
and movement. 

So we return, by a round-about way, to the 
conclusions worked out in the first chapter of 
this book. Our perception, we said, is originally 
in things rather than in the mind, without us 
rather than within. The several kinds of percep 
tion correspond to so many directions actually 
marked out in reality. But, we added, this 



perception, which coincides with its object, exists 
rather in theory than in fact : it could only 
happen if we were shut up within the present 
moment. In concrete perception memory inter 
venes, and the subjectivity of sensible qualities 
is due precisely to the fact that our consciousness, 
which begins by being only memory, prolongs a 
plurality of moments into each other, contract 
ing them into a single intuition. 

Consciousness and matter, body and soul, were 
thus seen to meet each other in perception. But 
Perception m one as P ec t this idea remained for us 
obscure, because our perception, and con- 
sequently also our consciousness, seemed 
of tnus to snare m the divisibility which is 
action. attributed to matter. If, on the dualis- 
tic hypothesis, we naturally shrink from accepting 
the partial coincidence of the perceived object 
and the perceiving subject, it is because we are 
conscious of the undivided unity of our percep 
tion, whereas the object appears to us to be, 
in essence, infinitely divisible. Hence the hypo 
thesis of a consciousness with inextensive sensa 
tions, placed over against an extended multiplicity. 
But if the divisibility of matter is entirely relative 
to our action thereon, that is to say to our faculty 
of modifying its aspect, if it belongs not to 
matter itself but to the space which we throw 
beneath this matter in order to bring it within 
our grasp, then the difficulty disappears. Ex 
tended matter, regarded as a whole, is like a 


consciousness where everything balances and 
compensates and neutralizes everything else ; 
it possesses in very truth the indivisibility of our 
perception ; so that, inversely, we may without 
scruple attribute to perception something of the 
extensity of matter. These two terms, perception 
and matter, approach each other in the measure 
that we divest ourselves of what may be called 
the prejudices of action : sensation recovers ex- 
tensity, the concrete extended recovers its natural 
continuity and indivisibility.. And homogeneous 
space, which stood between the two terms like an 
insurmountable barrier, is then seen to have no 
other reality than that of a diagram or a symbol. 
It interests the behaviour of a being which acts upon 
matter, but not the work of a mind which specu 
lates on its essence. 

Thereby also some light may be thrown 
upon the problem towards which all our en- 
ordinary quiries converge, that of the union of 
body and soul. The obscurity of this 
problem, on the dualistic hypothesis, 
comes from the double fact that matter 
i s considered as essentially divisible and 
every state of the soul as rigorously in- 
thcm. extensive, so that from the outset the 

communication between the two terms is severed. 
And when we go more deeply into this double 
postulate, we discover, in regard to matter, a 
confusion of concrete and indivisible extensity 
with the divisible space which underlies it ; and 


also, in regard to mind, the illusory idea that there 
are no degrees, no possible transition, between 
the extended and the unextended. But if these 
two postulates involve a common error, if there 
is a gradual passage from the idea to the image 
and from the image to the sensation ; if, in the 
measure in which it evolves towards actuality, 
that is to say towards action, the mental state 
draws nearer to extension ; if, finally, this 
extension once attained remains undivided and 
therefore is not out of harmony with the unity of 
the soul ; we can understand that spirit can 
rest upon matter and consequently unite with 
it in the act of pure perception, yet nevertheless 
be radically distinct from it. It is distinct from 
matter in that it is, even then, memory, that is to 
say a synthesis of past and present with a view 
to the future, in that it contracts the moments of 
this matter in order to use them and to manifest 
itself by actions which are the final aim of its 
union with the body. We were right, then, when 
we said, at the beginning of this book, that the 
distinction between body and mind must be estab 
lished in terms not of space but of time. 

The mistake of ordinary dualism is that it 
starts from the spatial point of view : it puts on 
the one hand matter with its modifications in 
space, on the other unextended sensations in con 
sciousness. Hence the impossibility of under 
standing how the spirit acts upon the body or the 
body upon spirit. Hence hypotheses which are 


andean be nothing but disguised statements of the 
fact, the idea of a parallelism or of a pre-estab 
lished harmony. But hence also the impossibility 
of constituting either a psychology of memory or 
a metaphysic of matter. We have striven to show 
that this psychology and this metaphysic are 
bound up with each other, and that the difficul 
ties are less formidable in a dualism which, starting 
from pure perception, where subject and object 
coincide, follows the development of the two terms 
in their respective durations, matter, the further 
we push its analysis, tending more and more to be 
only a succession of infinitely rapid moments which 
may be deduced each from the other and thereby are 
equivalent to each other spirit being in perception 
already memory, and declaring itself more and 
more as a prolonging of the past into the present, 
a progress, a true evolution. 

But does the relation of body and mind become 
thereby clearer ? We substitute a temporal for 
But the dis- a spatial distinction : are the two terms 
tween md an Y the more able to unite ? It must be 
oum a b t e er observed that the first distinction does 
ofo e i S^eT not admit of degree : matter is supposed 
to be in space, spirit to be extra- 
spatial; there is no possible transition 
degrees. between them. But if, in fact, the 
humblest function of spirit is to bind together 
the successive moments of the duration of 
things, if it is by this that it comes into con 
tact with matter and by this also that it is first 


of all distinguished from matter, we can con 
ceive an infinite number of degrees between matter 
and fully developed spirit a spirit capable of 
action which is not only undetermined, but 
also reasonable and reflective. Each of these suc 
cessive degrees, which measures a growing inten 
sity of life, corresponds to a higher tension of dura 
tion and is made manifest externally by a greater 
development of the sensori-motor system. But 
let us consider this nervous system itself : we note 
that its increasing complexity appears to allow an 
ever greater latitude to the activity of the living 
being, the faculty of waiting before reacting, and 
of putting the excitation received into relation 
with an ever richer variety of motor mechanisms. 
Yet this is only the outward aspect ; and the more 
complex organization of the nervous system, which 
seems to assure the greater independence of the 
living being in regard to matter, is only the 
material symbol of that independence itself, that 
is to say of the inner energy which allows the 
being to free itself from the rhythm of the flow 
of things, and to retain in an ever higher degree the 
past in order to influence ever more deeply the 
future, the symbol, in the special sense which 
we give to the word, of its memory. Thus, 
between brute matter and the mind most cap 
able of reflexion there are all possible intensities 
of memory or, what comes to the same thing, 
all the degrees of freedom. On the first hypo 
thesis, that which expresses the distinction be- 


tween spirit and body in terms of space, body 
and spirit are like two railway lines which cut 
each other at a right angle ; on the second, the 
rails come together in a curve, so that we pass 
insensibly from the one to the other. 

But have we here anything but a metaphor ? 
Does not a marked distinction, an irreducible oppo 
sition, remain between matter properly so-called 
and the lowest degree of freedom or of memory ? 
Yes, no doubt, the distinction subsists, but union 
becomes possible, since it would be given, under 
the radical form of a partial coincidence, in pure 
perception. The difficulties of ordinary dualism 
come, not from the distinction of the two terms, 
but from the impossibility of seeing how the one 
is grafted upon the other. Now, as we have 
shown, pure perception, which is the lowest degree 
of mind, mind without memory is really part 
of matter, as we understand matter. We may 
go further : memory does not intervene as a func 
tion of which matter has no presentiment and 
which it does not imitate in its own way. If 
matter does not remember the past, it is because 
it repeats the past unceasingly, because, subject 
to necessity, it unfolds a series of moments of 
which each is the equivalent of the preceding 
moment and may be deduced from it : thus 
its past is truly given in its present. But a 
being which evolves more or less freely creates 
something new every moment : in vain, then, 
should we seek to read its past in its present 


unless its past were deposited within it in the form 
of memory. Thus, to use again a metaphor 
which has more than once appeared in this book, 
it is necessary, and for similar reasons, that the 
past should be acted by matter, imagined by mind. 


I. THE idea that we have disengaged from the 
facts and confirmed by reasoning is that our body 
The body an * s an instrument of action, and of action 
S s So nt omv - I* 1 no degree, in no sense, under 
only - no aspect, does it serve to prepare, far 

less to explain, a representation. Consider ex 
ternal perception : there is only a difference of 
degree, not of kind, between the so-called percep 
tive faculties of the brain and the reflex functions 
of the spinal cord. While the spinal cord trans 
forms the excitations received into movements 
which are more or less necessarily executed, the 
brain puts them into relation with motor mechan 
isms which are more or less freely chosen ; but 
that which the brain explains in our perception is 
action begun, prepared or suggested, it is not 
perception itself. Consider memory, the body 
retains motor habits capable of acting the past 
over again ; it can resume attitudes in which 
the past will insert itself ; or, again, by the repeti 
tion of certain cerebral phenomena which have 
prolonged former perceptions, it can furnish to 
remembrance a point of attachment with the 
actual, a means of recovering its lost influence 
upon present reality : but in no case can the brain 



store up recollections or images. Thus, neither in 
perception, nor in memory, nor a fortiori in the 
higher attainments of mind, does the body con 
tribute directly to representation. By develop 
ing this hypothesis under its manifold aspects and 
thus pushing dualism to an extreme, we appeared 
to divide body and soul by an impassable abyss. 
In truth, we were indicating the only possible 
means of bringing them together. 

II. All the difficulties raised by this problem, 
either in ordinary dualism, or in materialism and 
Perception idealism, come from considering, in the 
Sie d p hySSaT phenomena of perception and memory, 
menta! are the physical and the mental as duplicates 
dSpiicJtw of the one of the other. Suppose I place 
each other, myself at the materialist point of view 
of the epiphenomenal consciousness : I am quite 
unable to understand why certain cerebral pheno 
mena are accompanied by consciousness, that is 
to say, of what use could be, or how could ever 
arise, the conscious repetition of the material uni 
verse I have begun by positing. Suppose I 
prefer idealism: I then allow myself only per 
ceptions, and my body is one of them. But 
whereas observation shows me that the images 
I perceive are entirely changed by very slight 
alterations of the image I call my body (since 
I have only to shut my eyes and my visual 
universe disappears), science assures me that 
all phenomena must succeed and condition one 
another according to a determined order, in which 


effects are strictly proportioned to causes. I 
am obliged, therefore, to seek, in the image which 
I call my body, and which follows me everywhere, 
for changes which shall be the equivalents but 
the well-regulated equivalents, now deducible 
from each other of the images which succeed 
one another around my body : the cerebral 
movements, to which I am led back in this 
way, again are the duplicates of my percep 
tions. It is true that these movements are 
still perceptions, possible perceptions, so that 
this second hypothesis is more intelligible than 
the first ; but, on the other hand, it must sup 
pose, in its turn, an inexplicable correspondence 
between my real perception of things and my 
possible perception of certain cerebral movements 
which do not in any way resemble these things. 
When we look at it closely, we shall see that this 
is the reef upon which all idealism is wrecked : 
there is no possible transition from the order 
which is perceived by our senses to the order which 
we are to conceive for the sake of our science, 
or, if we are dealing more particularly with 
the Kantian idealism, no possible transition from 
sense to understanding. So my only refuge 
seems to be ordinary dualism. I place matter 
on this side, mind on that, and I suppose that 
cerebral movements are the cause or the occasion 
of my representation of objects. But if they 
are its cause, if they are enough to produce it, 
I must fall back, step by step, upon the material- 


istic hypothesis of an epiphenomenal conscious 
ness. If they are only its occasion, I thereby suppose 
that they do not resemble it in any way, and so, 
depriving matter of all the qualities which I con 
ferred upon it in my representation, I come back 
to idealism. Idealism and materialism are then 
the two poles between which this kind of dualism 
will always oscillate ; and when, in order to main 
tain the duality of substances, it decides to make 
them both of equal rank, it will be led to regard 
them as two translations of one and the same 
original, two parallel and predetermined develop 
ments of a single principle, and thus to deny their 
reciprocal influence, and, by an inevitable conse 
quence, to sacrifice freedom. 

Now, if we look beneath these three hypo 
theses, we find that they have a common basis : 
The mistake a ^ three regard the elementary opera- 
SfleJ? that tions * the mind > perception and 
SlaSenwrF memory, as operations of pure know- 
knowiedge. ledge. What they place at the origin 
j e to they * consc i usness is either the useless 
action. duplicate of an external reality or 
the inert material of an intellectual construction 
entirely disinterested: but they always neglect 
the relation of perception with action and of 
memory with conduct. Now, it is no doubt pos 
sible to conceive, as an ideal limit, a memory and 
a perception that are disinterested ; but, in fact, 
it is towards action that memory and perception 
are turned ; it is action that the body pre- 


pares. Do we consider perception ? The grow 
ing complexity of the nervous system shunts 
the excitation received on to an ever larger 
variety of motor mechanisms, and so sketches 
out simultaneously an ever larger number of 
possible actions. Do we turn to memory ? We 
note that its primary function is to evoke all 
those past perceptions which are analogous 
to the present perception, to recall to us what 
preceded and followed them, and so to suggest 
to us that decision which is the most useful. 
But this is not all. By allowing us to grasp in a 
single intuition multiple moments of duration, it 
frees us from the movement of the flow of things, 
that is to say, from the rhythm of necessity. The 
more of these moments memory can contract into 
one, the firmer is the hold which it gives to us on 
matter : so that the memory of a living being 
appears indeed to measure, above all, its powers of 
action upon things, and to be only the intellectual 
reverberation of this power. Let us start, then, 
from this energy, as from the true principle : let 
us suppose that the body is a centre of action, and 
only a centre of action. We must see what con 
sequences thence result for perception, for memory, 
and for the relations between body and mind. 

III. To take perception first. Here is my body 
with its perceptive centres. These centres 
Perception vibrate, and I have the representation 
of things. On the other hand I have 
supposed that these vibrations can 


neither produce nor translate my perception. 
It is, then, outside them. Where is it ? I can 
not hesitate as to the answer : positing my body, 
I posit a certain image, but with it also the 
aggregate of the other images, since there is no 
material image which does not owe its qualities, 
its determinations, in short its existence, to the 
place which it occupies in the totality of the uni 
verse. My perception can, then, only be some 
part of these objects themselves ; it is in them 
rather than they in it. But what is it exactly 
within them ? I see that my perception appears 
to follow all the vibratory detail of the so- 
called sensitive nerves ; and on the other hand 
I know that the role of their vibrations is solely to 
prepare the reaction of my body on neighbouring 
bodies, to sketch out my virtual actions. Per 
ception, therefore, consists in detaching, from the 
totality of objects, the possible action of my body 
upon them. Perception appears, then, as only a 
choice. It creates nothing ; its office, on the con 
trary, is to eliminate from the totality of images 
all those on which I can have no hold, and then, 
from each of those which I retain, all that does not 
concern the needs of the image which I call my 
body. Such is, at least, much simplified, the way 
we explain or describe schematically what we 
have called pure perception. Let us mark out 
at once the intermediate place which we thus 
take up between realism and idealism. 

That every reality has a kinship, an analogy, 


in short a relation with consciousness this is 
Though it what we concede to idealism by the very 
only a part fact that we term things images. No 
things. philosophical doctrine, moreover, pro 
vided that it is consistent with itself, can escape 
from this conclusion. But if we could assemble 
all the states of consciousness, past, present, and 
possible, of all conscious beings, we should still 
only have gathered a very small part of material 
reality, because images outrun perception on 
every side. It is just these images that science 
and metaphysic seek to reconstitute, thus restor 
ing the whole of a chain of which our perception 
grasps only a few links. But in order thus to 
discover between perception and reality the 
relation of the part to the whole, it is necessary to 
leave to perception its true office, which is to 
prepare actions. This is what idealism fails to do. 
Why is it unable, as we said just now, to pass 
from the order manifested in perception to the 
order which is successful in science, that is to 
say, from the contingency with which our sensa 
tions appear to follow each other to the deter 
minism which binds together the phenomena of 
nature ? Precisely because it attributes to con 
sciousness, in perception, a speculative r61e, so that 
it is impossible to see what interest this conscious 
ness has in allowing to escape, between two sen 
sations for instance, the intermediate links through 
which the second might be deduced from the first. 
These intermediaries and their strict order thus 


remain obscure, whether, with Mill, we make the 
intermediaries into possible sensations/ or, 
with Kant, hold the substructure of the order 
to be the work of an impersonal understand 
ing. But suppose that my conscious perception 
has an entirely practical destination, that it 
simply indicates, in the aggregate of things, that 
which interests my possible action upon them : 
I can then understand that all the rest escapes 
me, and that, nevertheless, all the rest is of the 
same nature as what I perceive. My conscious 
ness of matter is then no longer either subjective, 
as it is for English idealism, or relative, as it 
is for the Kantian idealism. It is not subjec 
tive, for it is in things rather than in me. It is 
not relative, because the relation between the 
phenomenon and the thing is not that of 
appearance to reality, but merely that of the part 
to the whole. 

Here we seem to return to realism. But real 
ism, unless corrected on an essential point, is as 
The mistake inacceptable as idealism, and for the 

is to set up . . , 

homogeneous same reason. Idealism, we said, cannot 

space as a real . , , . 

or even ideal pass from the order manifested in per- 

medium prior v i_ r i 

to extension, ception to the order which is successful 
in science, that is to say to reality. Inversely, 
realism fails to draw from reality the immediate 
consciousness which we have of it. Taking the 
point of view of ordinary realism, we have, on 
the one hand, a composite matter made up of 
more or less independent parts, diffused through- 


out space, and, on the other, a mind which can 
have no point of contact with matter, unless it 
be, as materialists maintain, the unintelligible 
epiphenomenon. If we prefer the standpoint 
of the Kantian realism, we find between the 
thing-in-itself, that is to say the real, and the 
sensuous manifold from which we construct our 
knowledge, no conceivable relation, no common 
measure. Now, if we get to the bottom of these 
two extreme forms of realism, we see that they 
converge towards the same point : both raise homo 
geneous space as a barrier between the intellect 
and things. The simpler realism makes of this 
space a real medium, in which things are in sus 
pension ; Kantian realism regards it as an ideal 
medium, in which the multiplicity of sensations 
is coordinated ; but for both of them this 
medium is given to begin with, as the necessary 
condition of what comes to abide in it. And if we 
try to get to the bottom of this common hypo 
thesis, in its turn, we find that it consists in at 
tributing to homogeneous space a disinterested 
office : space is supposed either merely to uphold 
material reality, or to have the function, still 
purely speculative, of furnishing sensations with 
means of coordinating themselves. So that 
the obscurity of realism, like that of idealism, 
comes from the fact that, in both of them, our 
conscious perception and the conditions of our 
conscious perception are assumed to point to 
pure knowledge, not to action. But suppose now 


that this homogeneous space is not logically an 
terior, but posterior to material things and to 
the pure knowledge which we can have of them ; 
suppose that extensity is prior to space ; suppose 
that homogeneous space concerns our action and 
only our action, being like an infinitely fine net 
work which we stretch beneath material con 
tinuity in order to render ourselves masters of 
it, to decompose it according to the plan of our 
activities and our needs. Then, not only has our 
hypothesis the advantage of bringing us into 
harmony with science, which shows us each thing 
exercising an influence on all the others and con 
sequently occupying, in a certain sense, the whole 
of the extended (although we perceive of this 
thing only its centre and mark its limits at the 
point where our body ceases to have any hold 
upon it). Not only has it the advantage, in 
metaphysic, of suppressing or lessening the contra 
dictions raised by divisibility in space, contra 
dictions which always arise, as we have shown, 
from our failure to dissociate the two points of 
view, that of action from that of knowledge. It 
has, above all, the advantage of overthrowing 
the insurmountable barriers raised by realism be 
tween the extended world and our perception of 
it. For whereas this doctrine assumes on the one 
hand an external reality which is multiple and 
divided, and on the other sensations alien from 
extensity and without possible contact with it, 
we find that concrete extensity is not really 


divided, any more than immediate perception is 
in truth unextended. Starting from realism, we 
come back to the point to which idealism had led 
us ; we replace perception in things. And we see 
realism and idealism ready to come to an under 
standing when we set aside the postulate, uncriti 
cally accepted by both, which served them as a 
common frontier. 

To sum up : if we suppose an extended con 
tinuum, and, in this continuum, the centre of real 
action which is represented by our body, its 
activity will appear to illumine all those parts 
of matter with which at each successive moment 
it can deal. The same needs, the same power of 
action, which have delimited our body in matter, 
will also carve out distinct bodies in the sur 
rounding medium. Everything will happen as if 
we allowed to filter through us that action of ex 
ternal things which is real, in order to arrest and 
retain that which is virtual : this virtual action of 
things upon our body and of our body upon things 
is our perception itself. But since the excitations 
which our body receives from surrounding bodies 
determine unceasingly, within its substance, nascent 
reactions, since these internal movements of the 
cerebral substance thus sketch out at every mo 
ment our possible action on things, the state of 
the brain exactly corresponds to the perception. 
It is neither its cause, nor its effect, nor in any 
sense its duplicate : it merely continues it, the 
perception being our virtual action and the cere 
bral state our action already begun. 


IV. But this theory of pure perception * had 
to be both qualified and completed in regard to two 
Real action points. For the so-called pure percep- 
Stton irtnal tion > which is like a fragment of reality, 
SSuS^d detached just as it is, would belong to a 
memory. being unable to mingle with the percep 
tion of other bodies that of its own body, that is 
to say, its affections ; nor with its intuition of 
the actual moment that of other moments, that 
is to say, its memory. In other words, we have, 
to begin with, and for the convenience of study, 
treated the living body as a mathematical point 
in space and conscious perception as a mathe 
matical instant in time. We then had to restore 
to the body its extensity and to perception its 
duration. By this we restored to consciousness 
its two subjective elements, affectivity and 

What is an affection ? Our perception, we 
said, indicates the possible action of our body on 
others. But our body, being extended, is capable 
of acting upon itself as well as upon other bodies. 
Into our perception, then, something of our body 
must enter. When we are dealing with external 
bodies, these are, by hypothesis, separated from 
ours by a space, greater or less, which measures 
the remoteness in time of their promise or of 
their menace : this is why our perception of these 
bodies indicates only possible actions. But the 
more the distance diminishes between these 
bodies and our own, the more the possible action 


tends to transform itself into a real action, the 
call for action becoming more urgent in the 
measure and proportion that the distance dimi 
nishes. And when this distance is nil, that is to 
say when the body to be perceived is our own 
body, it is a real and no longer a virtual action 
that our perception sketches out. Such is, 
precisely, the nature of pain, an actual effort of 
the damaged part to set things to rights, an 
effort that is local, isolated, and thereby con 
demned to failure, in an organism which can no 
longer act except as a whole. Pain is therefore 
in the place where it is felt, as the object is at the 
place where it is perceived. Between the affec 
tion felt and the image perceived there is this 
difference, that the affection is within our body, 
the image outside our body. And that is why the 
surface of our body, the common limit of this and 
of other bodies, is given to us in the form 
both of sensations and of an image. 

In this interiority of affective sensation con 
sists its subjectivity ; in that exteriority of 
images in general their objectivity. But here 
again we encounter the ever-recurring mistake 
with which we have been confronted throughout 
this work. It is supposed that perception and 
sensation exist for their own sake ; the philosopher 
ascribes to them an entirely speculative function ; 
and, as he has overlooked those real and virtual 
actions with which sensation and perception are 
bound up and by which, according as the action 


is virtual or real, perception and sensation are 
characterized and distinguished, he becomes un 
able to find any other difference between them 
than a difference of degree. Then, profiting by 
the fact that affective sensation is but vaguely 
localized (because the effort it involves is an 
indistinct effort) at once he declares it to be 
unextended ; and these attenuated affections or 
unextended sensations he sets up as the material 
with which we are supposed to build up images 
in space. Thereby he condemns himself to an 
impossibility of explaining either whence arise 
the elements of consciousness, or sensations, which 
he sets up as so many absolutes, or how, unex 
tended, they find their way to space and are co 
ordinated there, or why, in it, they adopt a par 
ticular order rather than any other, or, finally, 
how they manage to make up an experience which 
is regular and common to all men. This experi 
ence, the necessary field of our activity, is, on 
the contrary, what we should start from. Pure 
perceptions, therefore, or images, are what we 
should posit at the outset. And sensations, far 
from being the materials from which the image 
is wrought, will then appear as the impurity 
which is introduced into it, being that part of 
our own body which we project into all others. 
V. But, as long as we confine ourselves to 
sensation and to pure perception, we can hardly 
be said to be dealing with the spirit. No doubt 
we demonstrate, as against the theory of an 


epiphenomenal consciousness, that no cerebral 

state is the equivalent of a perception. 

spirit, not a No doubt the choice of perceptions from 

manifesto- . . , . ,, , 

tion of among images in general is the effect of a 
discernment which foreshadows spirit. No 
doubt also the material universe itself, denned as 
the totality of images, is a kind of consciousness, 
a consciousness in which everything compensates 
and neutralizes everything else, a consciousness of 
which all the potential parts, balancing each 
other by a reaction which is always equal to the 
action, reciprocally hinder each other from stand 
ing out. But to touch the reality of spirit we 
must place ourselves at the point where an indi 
vidual consciousness, continuing and retaining the 
past in a present enriched by it, thus escapes the 
law of necessity, the law which ordains that the 
past shall ever follow itself in a present which 
merely repeats it in another form, and that all 
things shall ever be flowing away. When we pass 
from pure perception to memory, we definitely 
abandon matter for spirit. 

VI. The theory of memory, around which 
the whole of our work centres, must be both 
the theoretic consequence and the experimental 
verification of our theory of pure perception. 
That the cerebral states which accompany per 
ception are neither its cause nor its duplicate, 
and that perception bears to its physiological 
counterpart the relation of a virtual action to an 
action begun this we cannot substantiate by 


facts, since on our hypothesis everything is bound 
to happen as if perception were a consequence of 
the state of the brain. For, in pure perception, 
the perceived object is a present object, a body 
which modifies our own. Its image is then ac 
tually given, and therefore the facts permit us to 
say indifferently (though we are far from knowing 
our own meaning equally well in the two cases) 
that the cerebral modifications sketch the nascent 
reactions of our body or that they create in 
consciousness the duplicate of the present image. 
But with memory it is otherwise, for a remem 
brance is the representation of an absent object. 
Here the two hypotheses must have opposite con 
sequences. If, in the case of a present object, a 
state of our body is thought sufficient to create 
the representation of the object, still more must 
it be thought so in the case of an object 
that is represented though absent. It is neces 
sary therefore, on this theory, that the remem 
brance should arise from the attenuated repetition 
of the cerebral phenomenon which occasioned the 
primary perception, and should consist simply 
in a perception weakened. Whence this double 
thesis : Memory is only a function of the brain, and 
there is only a difference of intensity between per 
ception and recollection. If, on the contrary, the 
cerebral state in no way begets our perception of 
the present object but merely continues it, it may 
also prolong and convert into action the recol 
lection of it which we summon up, but it cannot 


give birth to that recollection. And as, on 
the other hand, our perception of the present 
object is something of that object itself, our 
representation of the absent object must be a 
phenomenon of quite another order than percep 
tion, since between presence and absence there are 
no degrees, no intermediate stages. Whence this 
double thesis, which is the opposite of the former : 
Memory is something other than a function of the 
brain, and there is not merely a difference of degree, 
but of kind, between perception and recollection. 
The conflict between the two theories now takes 
an acute form ; and this time experience can 
judge between them. 

We will not here recapitulate in detail the proof 
we have tried to elaborate, but merely recall its 
essential points. All the arguments from fact, 
which may be invoked in favour of a probable 
accumulation of memories in the cortical substance, 
are drawn from localized disorders of memory. 
But, if recollections were really deposited in the 
brain, to definite gaps in memory characteristic le 
sions of the brain would correspond. Now, in those 
forms of amnesia in which a whole period of our 
past existence, for example, is abruptly and entirely 
obliterated from memory, we do not observe any 
precise cerebral lesion ; and, on the contrary, in those 
disorders of memory where cerebral localization is 
distinct and certain, that is to say, in the different 
types of aphasia and in the diseases of visual or 
auditory recognition, we do not find that certain 


definite recollections are as it were torn from their 
seat, but that it is the whole faculty of remember 
ing that is more or less diminished in vitality, 
as if the subject had more or less difficulty in 
bringing his recollections into contact with the 
present situation. The mechanism of this con 
tact was, therefore, what we had to study in 
order to ascertain whether the office of the brain 
is not rather to ensure its working than to im 
prison the recollections in cells. 

We were thus led to follow through its 

windings the progressive movement by which 

past and present come into contact with 

Recognition. , , , . , 

each other, that is to say, the process 
of recognition. And we found, in fact, that the 
recognition of a present object might be effected 
in two absolutely different ways, but that in 
neither case did the brain act as a reservoir of 
images. Sometimes, by an entirely passive recog 
nition, rather acted than thought, the body re 
sponds to a perception that recurs by a move 
ment or attitude that has become automatic : in 
this case everything is explained by the motor 
apparatus which habit has set up in the body, 
and lesions of the memory may result from the 
destruction of these mechanisms. Sometimes, on 
the other hand, recognition is actively produced 
by memory-images which go out to meet the 
present perception ; but then it is necessary that 
these recollections, at the moment that they over 
lie the perception, should be able to set going 


in the brain the same machinery that percep 
tion ordinarily sets to work in order to produce 
actions ; if not foredoomed to impotence, they 
will have no tendency to become actual. And 
this is why, in all cases where a lesion of the brain 
attacks a certain category of recollections, the 
affected recollections do not resemble each other 
by all belonging to the same period, for instance, 
or by any logical relationship to each other, but 
simply in that they are all auditive, or all visual, 
or all motor. That which is damaged appears to 
be the various sensorial or motor areas, or, more 
often still, those appendages which permit of their 
being set going from within the cortex, rather than 
the recollections themselves . We even went further, 
and by an attentive study of the recognition of 
words, as also of the phenomena of sensory apha 
sia, we endeavoured to prove that recognition 
is in no way effected by a mechanical awakening of 
memories that are asleep in the brain. It implies, 
on the contrary, a more or less high degree of ten 
sion in consciousness, which goes to fetch pure re 
collections in pure memory in order to materialize 
them progressively by contact with the present 

But what is this pure memory, what are pure 
recollections ? By the answer to this enquiry we 
completed the demonstration of our thesis. We 
had just established its first point, that is to say, 
that memory is something other than a function 
of the brain. We had still to show, by the analysis 


of pure recollection/ that there is not between 
recollection and perception a mere difference of 
degree but a radical difference of kind. 

VII. Let us point out to begin with the meta 
physical, and no longer merely psychological, 
bearing of this last problem. No doubt 

The different , . . , , , 

planes of con- we have a thesis of pure psychology 

sciousness. . . , . . 

in a proposition such as this: recol 
lection is a weakened perception. But let there 
be no mistake : if recollection is only a weakened 
perception, inversely perception must be some 
thing like an intenser memory. Now the germ 
of English idealism is to be found here. This 
idealism consists in finding only a difference of 
degree, and not of kind, between the reality of the 
object perceived and the ideality of the object 
conceived. And the belief that we construct 
matter from our interior states and that per 
ception is only a true hallucination, also arises 
from this thesis. It is this belief that we have 
always combated whenever we have treated of 
matter. Either, then, our conception of matter 
is false, or memory is radically distinct from 

We have thus transposed a metaphysical prob 
lem so as to make it coincide with a psycho 
logical problem which direct observation is able 
to solve. How does psychology solve it ? If the 
memory of a perception were but this perception 
weakened, it might happen to us, for instance, to 
take the perception of a slight sound for the recol- 


lection of a loud noise. Now such a confusion 
never occurs. But we may go further, and say 
that the consciousness of a recollection never 
occurs as an actual weak state which we try to 
relegate to the past so soon as we become aware 
of its weakness. How, indeed, unless we already 
possessed the representation of a past previously 
lived, could we relegate to it the less intense 
psychical states, when it would be so simple to 
set them alongside of strong states as a present 
experience more confused beside a present exper 
ience more distinct ? The truth is that memory 
does not consist in a regression from the present to 
the past, but, on the contrary, in a progress from 
the past to the present. It is in the past that 
we place ourselves at a stroke. We start from a 
* virtual state which we lead onwards, step by 
step, through a series of different planes of con 
sciousness, up to the goal where it is materialized 
in an actual perception ; that is to say, up to 
the point where it becomes a present, active state ; 
in fine, up to that extreme plane of our conscious 
ness against which our body stands out. In 
this virtual state pure memory consists. 

How is it that the testimony of consciousness on 
this point is misunderstood ? How is it that we 
make of recollection a weakened perception, of 
which it is impossible to say either why we relegate 
it to the past, how we rediscover its date, or 
by what right it reappears at one moment rather 
than at another ? Simply because we forget the 


practical end of all our actual psychical states. 
Perception is made into a disinterested work of the 
mind, a pure contemplation. Then, as pure recol 
lection can evidently be only something of this 
kind (since it does not correspond to a present 
and urgent reality), memory and perception 
become states of the same nature, and between 
them no other difference than a difference of in 
tensity can be found. But the truth is that our 
present should not be denned as that which is 
more intense : it is that which acts on us and 
which makes us act, it is sensory and it is 
motor ; our present is, above all, the state of 
our body. Our past, on the contrary, is that 
which acts no longer but which might act, 
and will act by inserting itself into a present 
sensation of which it borrows the vitality. It 
is true that, from the moment when the recol 
lection actualizes itself in this manner, it ceases 
to be a recollection and becomes once more a 

We understand then why a remembrance can 
not be the result of a state of the brain. The state 
of the brain continues the remembrance ; it gives 
it a hold on the present by the materiality which 
it confers upon it : but pure memory is a spiritual 
manifestation. With memory we are in very truth 
in the domain of spirit. 

Association- VIIL lt WaS nOt OUr task tO ex ~ 

tmmf plore this domain. Placed at the con- 
ideas, fluence of mind and matter, desirous 


chiefly of seeing the one flow into the other, we 
had only to retain, of the spontaneity of intellect, 
its place of conjunction with bodily mechanism. 
In this way we were led to consider the phenomena 
of association and the birth of the simplest general 

What is the cardinal error of associationism ? 
It is to have set all recollections on the same plane, 
to have misunderstood the greater or less distance 
which separates them from the present bodily 
state, that is from action. Thus associationism 
is unable to explain either how the recollection 
clings to the perception which evokes it, or 
why association is effected by similarity or con 
tiguity rather than in any other way, or, finally, by 
what caprice a particular recollection is chosen 
among the thousand others which similarity or 
contiguity might equally well attach to the present 
perception. This means that associationism has 
mixed and confounded all the different planes of 
consciousness, and that it persists in regarding a less 
complete as a less complex recollection, whereas 
it is in reality a recollection less dreamed, more 
impersonal, nearer to action and therefore more 
capable of moulding itself like a ready-made 
garment upon the new character of the present 
situation. The opponents of associationism have, 
moreover, followed it on to this ground. They 
combat the theory because it explains the higher 
operations of the mind by association, but not 
because it misunderstands the true nature of 



association itself. Yet this is the original vice of 

Between the plane of action the plane in which 
our body has condensed its past into motor habits, 
and the plane of pure memory, where our mind 
retains in all its details the picture of our past life, 
we believe that we can discover thousands of 
different planes of consciousness, a thousand 
integral and yet diverse repetitions of the whole of 
the experience through which we have lived. To 
complete a recollection by more personal details 
does not at all consist in mechanically juxtaposing 
other recollections to this, but in transporting 
ourselves to a wider plane of consciousness, in 
going away from action in the direction of dream. 
Neither does the localizing of a recollection con 
sist in inserting it mechanically among other 
memories, but in describing, by an increasing 
expansion of the memory as a whole, a circle large 
enough to include this detail from the past. These 
planes, moreover, are not given as ready-made 
things superposed the one on the other. Rather 
they exist virtually, with that existence which is 
proper to things of the spirit. The intellect, for 
ever moving in the interval which separates them, 
unceasingly finds them again, or creates them anew : 
the life of intellect consists in this very movement. 
Then we understand why the laws of association 
are similarity and contiguity rather than any other 
laws, and why memory chooses among recollec 
tions which are similar or contiguous certain 


images rather than other images, and, finally, 
how by the combined work of body and mind the 
earliest general ideas are formed. The interest 
of a living being lies in discovering in the present 
situation that which resembles a former situation, 
and then in placing alongside of that present 
situation what preceded and followed the previous 
one, in order to profit by past experience. Of all 
the associations which can be imagined, those of 
resemblance and contiguity are therefore at first 
the only associations that have a vital utility. 
But, in order to understand the mechanism of 
these associations and above all the apparently 
capricious selection which they make of mem 
ories, we must place ourselves alternately on 
the two extreme planes of consciousness which 
we have called the plane of action and the plane 
of dream. In the first are displayed only motor 
habits ; these may be called associations which are 
acted or lived, rather than represented : here 
resemblance and contiguity are fused together, 
for analogous external situations, as they recur, 
have ended by connecting together certain bodily 
movements, and thenceforward the same auto 
matic reaction, in which we unfold these contiguous 
movements, will also draw from the situation 
which occasions them its resemblance with former 
situations. But, as we pass from movements to 
images and from poorer to richer images, resem 
blance and contiguity part company : they end 
by contrasting sharply with each other on that 


other extreme plane where no action is any 
longer affixed to the images. The choice of 
one resemblance among many, of one contig 
uity among others, is, therefore, not made at 
random : it depends on the ever varying de 
gree of the tension of memory, which, according 
to its tendency to insert itself in the present 
act or to withdraw from it, transposes itself as 
a whole from one key into another. And this 
double movement of memory between its two ex 
treme limits also sketches out, as we have shown, 
the first general ideas, motor habits ascending to 
seek similar images in order to extract resemblances 
from them, and similar images coming down 
towards motor habits, to fuse themselves, for 
instance, in the automatic utterance of the word 
which makes them one. The nascent generality 
of the idea consists, then, in a certain activity of 
the mind, in a movement between action and 
representation. And this is why, as we have said, 
it will always be easy for a certain philosophy to 
localize the general idea at one of the two ex 
tremities, to make it crystallize into words or 
evaporate into memories, whereas it really consists 
in the transit of the mind as it passes from one 
term to the other. 

IX. By representing elementary mental acti 
vity in this manner to ourselves, and by thus 

making of our body and all that sur- 
oi body rounds it the pointed end ever moving, 

ever driven into the future by the 


weight of our past, we were able to confirm and 
illustrate what we had said of the function of the 
body, and at the same time to prepare the way 
for an approximation of body and mind. 

For after having successively studied pure 
perception and pure memory, we still had to bring 
them together. If pure recollection is already 
spirit, and if pure perception is still in a sense 
matter, we ought to be able, by placing ourselves 
at their meeting place, to throw some light on 
the reciprocal action of spirit and matter. Pure, 
that is to say instantaneous, perception is, in fact, 
only an ideal, an extreme. Every perception fills 
a certain depth of duration, prolongs the past 
into the present, and thereby partakes of memory. 
So that if we take perception in its concrete 
form, as a synthesis of pure memory and pure 
perception, that is to say of mind and matter, we 
compress within its narrowest limits the problem 
of the union of soul and body. This is the attempt 
we have made especially in the latter part of this 

The opposition of the two principles, in dualism 
in general, resolves itself into the threefold opposi 
tion of the inextended and the extended, quality 
and quantity, freedom and necessity. If our 
conception of the function of the body, if our 
analyses of pure perception and pure memory, 
are destined to throw light on any aspect of the 
correlation of body and mind, it can only be on 
condition of suppressing or toning down these 


three oppositions. We will, then, examine them in 
turn, presenting here in a more metaphysical 
form the conclusions which we have made a 
point of drawing from psychology alone. 

ist. If we imagine on the one hand the extended 
really divided into corpuscles, for example, and 
on the other a consciousness with sen 
sations, in themselves inextensive, which 
come to project themselves into space, we shall 
evidently find nothing common to such matter 
and such a consciousness, to body and mind. 
But this opposition between perception and matter 
is the artificial work of an understanding which 
decomposes and recomposes according to its 
habits or its laws : it is not given in immediate 
intuition. What is given are not inextensive sen 
sations : how should they find their way back to 
space, choose a locality within it, and coordinate 
themselves there so as to build up an experience 
that is common to all men ? And what is real 
is not extension, divided into independent parts : 
how, being deprived of all possible relationship 
to our consciousness, could it unfold a series 
of changes of which the relations and the order 
exactly correspond to the relations and the order 
of our representations ? That which is given, 
that which is real, is something intermediate 
between divided extension and pure inexten- 
sion. It is what we have termed the extensive, 
Extensity is the most salient quality of percep 
tion. It is in consolidating and in subdividing 


it by means of an abstract space, stretched by 
us beneath it for the needs of action, that we 
constitute the composite and infinitely divisible 
extension. It is, on the other hand, in subtilizing 
it, in making it, in turn, dissolve into affective 
sensations and evaporate into a counterfeit of 
pure ideas, that we obtain those inextensive 
sensations with which we afterwards vainly 
endeavour to reconstitute images. And the two 
opposite directions in which we pursue this 
double labour open quite naturally before us, 
because it is a result of the very necessities of 
action that extension should divide itself up 
for us into absolutely independent objects (whence 
an encouragement to go on subdividing extension) ; 
andthat we should pass by insensible degrees from 
affection to perception (whence a tendency to 
suppose perception more and more inextensive). 
But our understanding, of which the func 
tion is to set up logical distinctions, and con 
sequently clean-cut oppositions, throws itself 
into each of these ways in turn, and follows each 
to the end. It thus sets up, at one extremity, 
an infinitely divisible extension, at the other 
sensations which are absolutely inextensive. And 
it creates thereby the opposition which it after 
wards contemplates amazed. 

2nd. Far less artificial is the opposition between 

quality and quantity, that is to say between 

consciousness and movement : but this 

Tension. . . .. 

opposition is radical only if we have 


already accepted the other. For if you suppose 
that the qualities of things are nothing but inex- 
tensive sensations affecting a consciousness, so 
that these qualities represent merely, as so 
many symbols, homogeneous and calculable 
changes going on in space, you must imagine be 
tween these sensations and these changes an 
incomprehensible correspondence. On the con 
trary, as soon as you give up establishing be 
tween them a priori this factitious contrariety, 
you see the barriers which seemed to separate 
them fall one after another. First, it is not 
true that consciousness, turned round on itself, is 
confronted with a merely internal procession of 
inextensive perceptions. It is inside the very 
things perceived that you put back pure percep 
tion, and the first obstacle is thus removed. You 
are confronted with a second, it is true : the homo 
geneous and calculable changes on which science 
works seem to belong to multiple and independent 
elements, such as atoms, of which these changes 
appear as mere accidents, and this multiplicity 
comes in between the perception and its object. 
But if the division of the extended is purely 
relative to our possible action upon it, the idea 
of independent corpuscles is a fortiori schematic 
and provisional. Science itself, moreover, allows 
us to discard it ; and so the second barrier falls. 
A last interval remains to be over-leapt : that 
which separates the heterogeneity of qualities from 
the apparent homogeneity of movements that 


are extended. But, just because we have set 
aside the elements, atoms or what not, to 
which these movements had been affixed, we 
are no longer dealing with that movement which 
is the accident of a moving body, with that 
abstract motion which the mechanician studies 
and which is nothing, at bottom, but the common 
measure of concrete movements. How could this 
abstract motion, which becomes immobility when 
we alter our point of reference, be the basis of 
real changes, that is, of changes that are felt ? 
How, composed as it is of a series of instantaneous 
positions, could it fill a duration of which the parts 
go over and merge each into the others ? Only one 
hypothesis, then, remains possible; namely, that 
concrete movement, capable, like consciousness, 
of prolonging its past into its present, capable, 
by repeating itself, of engendering sensible quali 
ties, already possesses something akin to con- 
ciousness, something akin to sensation. On this 
theory, it might be this same sensation diluted, 
spread out over an infinitely larger number of 
moments, this same sensation quivering, as we 
have said, like a chrysalis within its envelope. 
Then a last point would remain to be cleared 
up : how is the contraction effected, the con 
traction no longer of homogeneous movements 
into distinct qualities, but of changes that are 
less heterogeneous into changes that are more 
heterogeneous ? But this question is answered 
by our analysis of concrete perception : this 


perception, the living synthesis of pure per 
ception and pure memory, necessarily sums up 
in its apparent simplicity an enormous multi 
plicity of moments. Between sensible qualities, 
as regarded in our representation of them, 
and these same qualities treated as calculable 
changes, there is therefore only a difference in 
rhythm of duration, a difference of internal ten 
sion. Thus, by the idea of tension we have 
striven to overcome the opposition between quality 
and quantity, as by the idea of extension that 
between the inextended and the extended. Exten 
sion and tension admit of degrees, multiple but 
always determined. The function of the under 
standing is to detach from these two genera, 
extension and tension, their empty container, 
that is to say, homogeneous space and pure 
quantity, and thereby to substitute, for supple 
realities which permit of degrees, rigid abstrac 
tions born of the needs of action, which can 
only be taken or left ; and to create thus, for 
reflective thought, dilemmas of which neither 
alternative is accepted by reality. 

3rd. But if we regard in this way the relations 
of the extended to the inextended, of quality 
Freedom and to quantity, we shall have less difficulty 
necessity. j n comprehending the third and last 
opposition, that of freedom and necessity. Abso 
lute necessity would be represented by a perfect 
equivalence of the successive moments of dura 
tion, each to each. Is it so with the duration 


of the material universe ? Can each moment 
be mathematically deduced from the preceding 
moment ? We have throughout this work, and 
for the convenience of study, supposed that it 
was really so ; and such is, in fact, the distance 
between the rhythm of our duration and that of 
the flow of things, that the contingency of the 
course of nature, so profoundly studied in recent 
philosophy, must, for us, be practically equiva 
lent to necessity. So let us keep to our hypo 
thesis, though it might have to be attenuated. 
Even so, freedom is not in nature an im- 
perium in imperio. We have said that this 
nature might be regarded as a neutralized and 
consequently a latent consciousness, a conscious 
ness of which the eventual manifestations hold 
each other reciprocally in check, and annul each 
other precisely at the moment when they might 
appear. The first gleams which are thrown upon 
it by an individual consciousness do not therefore 
shine on it with an unheralded light : this con 
sciousness does but remove an obstacle ; it extracts 
from the whole that is real a part that is virtual, 
chooses and finally disengages that which interests 
it ; and although, by that intelligent choice, it indeed 
manifests that it owes to spirit its form, it assuredly 
takes from nature its matter. Moreover, while 
we watch the birth of that consciousness we are 
confronted, at the same time, by the apparition 
of living bodies, capable, even in their simplest 
forms, of movements spontaneous and unforeseen. 


The progress of living matter consists in a 
differentiation of function which leads first to 
the production and then to the increasing com 
plication of a nervous system capable of canali 
zing excitations and of organizing actions : 
the more the higher centres develop, the more 
numerous become the motor paths among which 
the same excitation allows the living being to 
choose, in order that it may act. An ever greater 
latitude left to movement in space this indeed 
is what is seen. What is not seen is the growing 
and accompanying tension of consciousness in 
time. Not only, by its memory of former experi 
ence, does this consciousness retain the past better 
and better, so as to organize it with the present in 
a newer and richer decision ; but, living with an 
intenser life, contracting, by its memory of the 
immediate experience, a growing number of exter 
nal moments in its present duration, it becomes 
more capable of creating acts of which the inner 
indetermination, spread over as large a multi 
plicity of the moments of matter as you please, 
will pass the more easily through the meshes of 
necessity. Thus, whether we consider it in time 
or in space, freedom always seems to have its 
roots deep in necessity and to be intimately 
organized with it. Spirit borrows from matter the 
perceptions on which it feeds, and restores them 
to matter in the form of movements which it 
has stamped with its own freedom. 


Achilles, The, of Zeno, 252. 

Action, and pure knowledge, xvii ; 
and pure memory, planes of, 210 ; 
and time, 23 ; necessary, 6 ; needs 
of, and bodies, 261 ; orientation 
of consciousness towards, 233 ; 
plane of, 130, 217 ; possible, 7 ; 
real and virtual, 310 ; reflex and 
voluntary, 81 ; the true point of 
departure, 67 ; useful, and pure 
knowledge, 262 ; virtual and real, 

Actual sensation and pure memory 
differ in kind, 179. 

Adaptation, the general aim of life, 

Adler, 143. 

Affection, 310 ; always localized, 61 ; 
and perception, difference between, 
53 ; has, from the outset, some 
extensity, 61 ; impurity in percep 
tion, 60 ; its source, 57. 

Affections, i ; an invitation to act, 2. 

Affective states, vaguely localized, 52. 

Amnesia, retrogressive, 224. 

Amnesias, systematized, 222. 

Aphasia, 231 ; cases of, 139 ; con 
ception of, xv ; diagrams of sen 
sory, 156 ; sensory, 149 ; sensory, 
evidence from certain forms of, 139. 

Aphasias, the true, 151. 

Apraxia, in. 

Amaud, 141, note ; 142, note. 

Arrow, The, of Zeno, 252. 

Association, not the primary fact, 
215 ; of ideas, in what it consists, 
103 ; of ideas, laws of, 212 ; of 
perceptions with memory, 106. 

Association?, of similarity and con 
tiguity, 212 ff. 

Associationism, error of, 171, 212, 
321 ; intellectualizes ideas too 
much, 213. 

Attention, and recognition, 119; a 
power of analysis, 124 ; compared 
to telegraph-clerk, 123 ; first, an 
adaptation of the body, 120 ; nega 
tively, inhibition of movement, 
120 perception and memory. 

relations of, 120 ff. ; to life, xiv, 
226 ; to life, conditioned by body, 

Atom, Faraday s theory of, 265 ; 
Kelvin s theory of, 265 ; modern 
theories of, 266 ; properties of, 263. 

Auditory, image, 99 ; memory, 133 ; 
memory of words, 161. 

Automatic, the, and the voluntary, 

Automatism, no ; wide range of, 99. 

Babilee, 149 note. 

Bain, 161. 

Ball, 201 note, 229 note. 

Ballet, 144 note. 

Bastian, 121 note, 140, 157 note. 

Bateman, ipi note, 141 note. 

Becoming, instantaneous section of, 

Berkeley, and Descartes, ix ; and 
mechanical philosophers, ix ; and 
the object, viii ; on extensity, 284 

Berlin, 101 note. 

Bernard, 101 note, 109 note, 144 
note, 149 note, 153 note, 156 note. 

Blindness and deafness, psychic, 1 32 ; 
word, 132 ; psychic, 108, in, 161 ; 
psychic, as a disturbance of motor 
habit, 115 ; psychic, two kinds of, 
115 ; word, two kinds of, 133. , 

Bodies, distinct, and the needs of life, 

Body, a centre of action, 5, 178 ; a 
centre of perceptions, 43 ; and 
mind, relation of, 295 ; and soul, 
relation of, 234 ; an instrument of 
action, 299 ; an instrument of 
choice, 233 ; a moving boundary 
between future and past, 88 ; a 
moving, trajectory of, 246 ; a 
place of passage, 196 ; conditions 
attention to life, 225 ; conscious 
ness of, is my present, 177 ; does 
not give rise to representation, 5 ; 
education of, 139 ; is that which 
fixes the mind, 226 ; known from 
within as well as from without, i ; 



provides for the exercise of choice, 
5 ; receives and gives back move 
ment, 5 ; structure of, 3 ; the 
living, its unique place, i. 

Bradley, 120 note. 

Brain, and memory, relation between, 
119 ; an instrument of analysis 
and of choice, 20 ; a telephonic 
exchange, 19 ; cannot beget repre 
sentation, 8 1 ; concerned with 
motor reaction, 8 ; functions of 
the, 1 8 ; injuries to the, effect of, 
231 ; lesions affect movements, 
not recollections, 88 ; lesions affect 
nascent or possible action, 120 ; 
lesions and recognition, attentive 
and inattentive, 132 ; lesions and 
the motor diagram, 143 ; not con 
cerned with conscious perception, 8. 

Broadbent, 101 note, 156. 

Brochard, 106 note. 

Centre oi representation, the body, 64. 

Centres, of force, 265 ; of perception, 
1 60 ; of verbal images, problem 
atic, 159. 

Cerebral, localization, 131; mechanism, 
conditions memories, does not 
ensure their survival, 84 ; me 
chanism, links the past with action, 
88 ; vibrations, cannot create 
images, 10 ; vibrations, contained 
in the material world, 10. 

Change, and permanence, 260. 

Character, a synthesis of past states, 

Charcpt, 109, 143, 156. 

Chemistry, studies bodies rather than 
matter, 263. 

Clerk-Maxwell, 263 note. 

Colours, and rhythm of movement, 

Common sense, and matter, x; and 
object, viii. 

Conceptualism and nominalism, 
criticism of, 202. 

Consciousness, actual, deals with 
useful, rejects the superfluous, 188 ; 
and matter, 276 ff.; and the inner 
history of things, 276 ; chief office 
of, 182 ; different planes of, 318 ff. ; 
double movement in, 216 ; illusion 
in regard to, 182 ; its office in per 
ception, 69 ; its part in affection, 2 ; 
not the synonym of existence, 181 ; 
of another tension than ours, 275 ; 
orientation of, towards action, 233 ; 
rhythm of, 272 ; the fringe of, 97; 
the note of the present, 181. 

Conscious perception, a discernment, 
31 ; is our power of choice, 26 ; 
materialist s view of, n. 

Contiguity and similarity, associa 

tions of, 212 ff. 
Continuity, universal, and science, 

Cowles, 228 note. 

Dawn, of human experience, 241. 

Deafness, and blindness, psychic, 132; 
and blindness, word, 132 ; psychic, 
does not hinder hearing, 161 ; word, 
two kinds of, 133 ; word, with re 
tention of acoustic memory, 142. 

Descartes, and Berkeley, ix ; and 
the laws of motion, 255. 

Diagram, the motor, and brain 
lesions, 143. 

Diagrams, of sensory aphasia, 156. 

Dichotomy, The, of Zeno, 251. 

Direction, sense of, 115. 

Dissociation, is primary, 215 

Dodds, in note. 

Dogmatism and empiricism, ignore 
duration, 242. 

Drawing, methods of, 116. 

Dream, plane of, 129, 218 ; power of, 


Dreamer, the, 198. 

Dreams, memory in, 200. 

Drugs, toxic, effect of, 228. 

Dualism, ordinary, 293 ff. ; trans 
cended, 236. 

Dunan, 286 note. 

Duration, 243 ; our own, and quality, 
271 ; tension of, determines the 
measure of liberty, 279 ; tensions of 

Duval, 200 note. 

Dynamises and mechanists, xvi. 

Dyslexic, 101 note. 

Ear, the mental, 166. 

Egger, 200 note. 

Eleatics, paradoxes of, 253. 

Empiricism and dogmatism, 239 ; 
ignore duration, 242. 

Epiphenomenalism, x. 

Epiphenomenon.and recollection, 104. 

Equilibrium, intellectual, how upset, 

Existence, capital problem of, 189 ; 
conditions implied in, 189 ; im 
plies conscious apprehension and 
regular connexion, 190 ; outside of 
consciousness, 183 ; real though 
unperceived, in time and in space, 

Exuer, and empty time, 272. 

Experience, human, dawn of, 241 ; 
the true starting-point, 312. 

Extended, the, and the inextended, 



Extension, 326 ; and artificial space, 

244 ; concrete, not bound up with 
inert space, 244 ; idea of, 237. 

Extensity, and inextension, 235 ; 
concrete, and homogeneous space, 
278 ; concrete, not within space, 
289 ; perceived, space conceived, 

245 ; perception of and sight, 286 ; 
visual and tactile, 65. 

Exteriority, notion of, 42. 

Faraday, and centres of force, 31 ; 
and the atom, 265. 

Force, centres of, 31, 265 ; in natural 
science, 257 ; metaphysical sense 
of the word, 257. 

Fouillee, 112 note. 

Freedom and necessity, 279, 325 ff., 
330 ff. ; degrees of, 296 ; two op 
posing points of view concerning, 


Freud, 157 note. 
Future, no grasp of without outlook 

over past, 69. 

General idea, essence of the, 2 10. 

Generality, 202. 

Genus, general idea of, 209. 

Goldscheider, 125. 

Granville, Mortimer, 101 note. 

Grashey, 125, 151 note. 

Graves, 153 note. 

Habit, 89 ; interpreted by memory, 
the study of psychologists, 95. 

Habit-memory, 90 ; acts, not repre 
sents, the past, 93 ; advantageous, 
94 ; comparatively rare, 94 ; in 
hibits spontaneous memory, 97; 
sets up a machine, 95. 

Habits, amassed in the body, 92 ; 
formed in action, influence specu 
lation, xvi. 

Hallucinations, negative, 131 ; veri 
dical, 73. 

Hamilton, 121 note. 

Hearing, intelligent, starts from the 
idea, 145 ; mental, 149. 

Heterogeneity, qualitative, 76. 

Hoffding, 107 note. 

Human experience, dawn of, 241. 

Idea, and sound, in speech, 154. 

Ideas, association of , laws of the, 212. 

Ideas, general, 201, 321 ; always in 
movement, 210 ; first experienced, 
then represented, 208 ; the essence 

Of, 2IO. 

Idealism, and materialism, 236; 
and realism, vii ; and realism, 
have a common postulate, 17, 283 ; 

English, 282, 287, 289 ; makes 
science an accident, 16 ; the ref 
on which it is wrecked, 301. 

Idealist, the, starts from perception, 

Idealists and realists, xvi. 

Image, a privileged, 64 ; formed in 
the object, 35 ; none without an 
object, 38 ; present and repre 
senting, 28 ; representation and 
thing, vii ; visual or auditory, 99. 

Image-centre, a kind of keyboard, 

Image- centres, 132. 

Images, and the body, i ; belong to 
two systems, 12 ; never any thing 
but things, 159 ; not created by 
cerebral vibrations, ip ; preserved 
for use, 70 ; recognition of, 86 ; 
the delimiting and fixing of, 233. 

Imagination, is not memory, 173. 

Indetermination, of the will, 35 ; re 
quires preservation of images per 
ceived, 69 ; the true principle, 21. 

Inextended, the, and the extended, 

Inextension, and extensity, 235. 

Insanity, a disturbance of the sensori- 
motor relations, 228 ; and present 
reality, 227. 

Intellectual equilibrium, how upset, 

Intellectual process, two radically 
distinct conceptions of, 127. 

Interpretation, general problem of, 145 

Intuition, actual and remembered, 
70 ; and contact with the real, 241 ; 
pure, gives an undivided continu 
ity, 239. 

James, William, 121 note, 286 note, 

289 note. 

Janet, Paul, 286 note. 
Janet, Pierre, xv note, 151 note, 229 

note, 230 note ; study of neuroses, 

Kant, 289 note ; and diversity of 
phenomena, 244 ; and speculative 
reason, 241 ; and the impersonal 
understanding, 306 ; on space and 
time, 281. 

Kantian criticism, ix. 

Kay, 102 note, 199 note. 

Kelvin, and the atom, 265. 

Keyboard, the internal, 165. 

Knowledge, relativity of, 241 ; useful 
and true, 243. 

Kulpe, 125. 

Kussmaul, in note, 141, 156 note 

Lange, 122 note. 


Language, elaborate and primitive, 

158 ; the hearing of an unknown, 


Laquer, in note. 
Learning by heart, 89 ft 
Lehmami, 105 note. 
Leibniz, on Descartes, 255. 
Leibnizian monads, 31. 
Lepine, 200 note. 
Lesions, brain and the motor diagram, 

Liberty, measure of determined by 

tension of duration, 279. 
Lichtheim, 140, 142 note, 156 note. 
Light, red, 272. 
Lissauer, 108, 116, 117. 
Living matter, progress of, 67. 
Localization, cerebral, 131. 
Lotze, 50. 
Luciani, 162 note. 

Magnan, 157 note. 

Man of impulse, 198. 

Marillier, 120 note, 121 note. 

Marc6, 141 note. 

Materialism and idealism, 236. 

Materialism and spiritualism, 13. 

Materialism, essence of, 79 ; true 
method of refuting, 80. 

Materiality, begets oblivion, 232. 

Matter, an aggregate of images, vii ; 
and common sense, vii ; and con 
sciousness, 276 ff. ; and percep 
tion, vii, 76 ; and perception, differ 
only in degree, 78 ; and percep 
tion, kinship of, 292 ; and spirit, 
reciprocal action of, 325 ; and 
spirit, transition between, 295 ; 
an ever renewed present, 178 ; 
artificial division of, 259 ; coin 
cides with pure perception, 81 ; 
considered before dissociation into 
existence and appearance, viii ; 
definition of, 8 ; existence and 
essence of, xvi ; has no occult 
power, 78, 81 ; in concrete per 
ception, 237 ; living, progress of, 
332 ; metaphysic of, 295 ; not the 
substratum of a knowledge, 82 ; 
philosophers conception of, vii ; 
philosophical theory of, 262 ff. ; 
philosophy of, 80 ; the vehicle of 
an action, 82. 

Maudsley, in, 121 note. 

Maury, 200 note. 

Mechanical philosophers and Berke 
ley, ix. 

Mechanism of speech, 139. 

Mechanists and dynamists, xvi. 

Memories, conditioned by cerebral 
mechanism, 84 ; supposed destruc 

tion of, 160 ; where stored. Fal 
lacy involved, 191. 

Memory, actualized in an image dif 
fers from pure memory, 181 ; and 
brain, 86 ; and brain, relation be 
tween, 119 ; and perception point 
to action, 302 ; a principle inde 
pendent of matter, 81 ; a privileged 
problem, xii, 83 ; auditory, of 
words, 147 ; bodily and true, their 
relation, 197 ; capital importance 
of problem of, 80 ; circles of, 127 ; 
contraction of, 129 ; different 
planes of, 129 ; empirical study of, 
83 ; expansion of, 128 ; function 
of, in relation to things, 279 ; gives 
subjective character to perception, 
80 ; habit, recalls similarity, 201 ; 
habit, inhibits spontaneous me 
mory, 97 ; how it becomes actual, 
162 ; independent, an appeal to, 
90 ; in dreams, 200 ; intersection 
of mind and matter, xii ; is spirit, 
313 ; its apparent oneness with 
the body, 82 ; its part in percep 
tion, 70 ; its twofold operation, 
80 ; loss of, 149 ; mixed forms of, 
103 ; needs motor aid to become 
actual, 152 ; not a manifestation 
of matter, 313 ; not an emanation 
of matter, 237 ; not destroyed by 
brain lesions, 132 ; of a sensation 
is not a nascent sensation, 174 ; of 
words, localization of denied, xv ; 
perception and attention, relations 
of, 1 20 ff. ; phenomena of, 81 ; 
primary function of, 303 ; psycho 
logical mechanism of, 82 ; psycho 
logy of, 295 ; pure, and action, 
planes of, 210 ; pure, and the 
memory-image, 170 ; pure, de 
tached from life, 179 ; pure, differs 
in kind from actual sensation, 179 ; 
pure, inextensive and powerless, 
1 80 ; pure, interests no part of the 
body, 179; pure, its reference to 
spirit, 78 ; representative, 94 ff.; 
reverberation, in consciousness, of 
indetermination, 70 ; spontaneous, 
in children and savages, 198 ; spon 
taneous, its exaltation and inhibi 
tion, 98 ; spontaneous, recalls dif 
ferences, 201; subjective side "f 
knowledge, 25 ; supplanting .per 
ception, 24 ; the condensing power 
of, 76 ; the two forms of, 89 ff.; to be 
sought apart from motor adapta 
tion, 119 ; true, records every mo 
ment of duration, 94 ; two forms, 
support each other, 98 ; two kinds 
of, 195 ; visual, 108. 

Memory-image, and habit memory, 



their coalescence, 103 ; and motor 
habit, distinct in kind, 103 ; and 
pure memory, 170. 

Memory-images, and recognition, 92 ; 
and the normal consciousness, 96 ; 
recognition by, 118 ; utility deter 
mines retention of, 97. 

Mental and physical, the, not mere 
duplicates, 300. 

Mental functions, utilitarian char 
acter of, xvii. 

Mental hearing, 149. 

Mental life, tones of, 221. 

Mental states, unconscious, 183. 

Metaphysical problems, empirical 
solution of, 83. 

Metaphysics and psychology, relation 
of, xv. 

Mill, J. S., and possible sensation, 306. 

Mind, and body, relation of, 295 ; 
degree of tension of, 126 ; normal 
work of, 225. 

Mnemonics, 101. 

Moeli, 157 note. 

Moment, the present, how consti 
tuted, 178. 

More, Henry, and Descartes, 255. 

Moremi de Tours, 228 note. 

Motion, and its cause, 257 ; in 
mechanics, only an abstraction, 

Motor aphasia, does not involve word 
deafness, 138. 

Motor apparatus, in course of con 
struction, 112. 

Motor diagram, the, 134, 136, 153 ; 
and brain lesions, 143. 

Movement, absolutely indivisible, 246 
ff. ; and its trajectory, 250 ff. ; 
as a change of quality, 258 ; can 
only produce movement, 119 ; 
essence of, 291 ; real, akin to con 
sciousness, 267 ; real, and ap 
parent, 258 ; real, for the physi 
cist, 254 ; real, quality rather than 
quantity, 267 ; real, the transfer 
ence of a state, 267 ; relative, for 
the mathematician, 254 ; rhythm 
of, and colours, 268 ; rhythm of, 
and sounds, 269. 

Movements, consolidated, difficulty 
in modifying their order, 112 ; 
indivisibles, occupying duration, 
268 ; in space and qualities in 
consciousness, 267 ; of imitation, 
124 ; prepare the choice among 
memory-images, 113; real, not 
merely change of position, 256. 

Moving body, 246 ff. 

Miiller, 100 note, 108, 116, 125. 

Miinck, 107 note. 

Miinsterberg, 125. 

Necessity, and freedom, 325, 330 ff ; 
natural and freedom, 279. 

Negative hallucinations, 151. 

Nerves, section of, 7. 

Nervous system, 3, 17, 227 ; a con 
ductor, 40 ; channel for the trans 
mission of movements, 81 ; con 
structed in view of action, 21. 

Newton, 257 note. 

Nominalism and conceptualism, 
criticism of, 202 ff. 

Object, the, and common sense, viii. 
Objects and facts are carved out of 

reality, 239. 

Oblivion and materiality, 232. 
Oppenheim, 99 note. 
Order of representation, necessary or 

contingent, 187. 
Orientation of consciousness, towards 

action, 233. 

Pain, a local effort, 56 ; real signifi 
cance of, 55; the nature of, 311. 

Parallelism, x. 

Past, an idea, 74 ; and present, differ 
in more than degree, 175 ; essen 
tially virtual, 173 ; that which 
acts no longer, 74 ; has ceased to 
be useful, 193 ; how stored up, 87 ; 
survival of, 193 ; survives in two 
forms, 87. 

Past states, synthesized in char 
acter, 1 88. 

Pathology, evidence from, 133. 

Perception, always full of memory 
images, 170 ; always occupies some 
duration, 25 ; and affection, dif 
ference between, 53 ; and matter, 
vii ; and matter, kinship of, 292 ; 
and memory, difference between, 
71 ; and memory, differ in kind, 
75 ; and memory-image, not 
things but a progress, 162 ; and 
memory, interpenetrate, 71 ; and 
memory point to action, 302 ; and 
space, 23 ; a question addressed 
to motor activity, 42 ; attention 
and memory, relations of, 120 ff. ; 
attentive, a reflexion, 124 ; centres 
of, 1 60 ; directed towards action, 
21 ; displays virtual action, 8 ; 
distinct, brought about by two 
opposite currents, 163 ; gives us 
thintrs-in-themselves, 303 ; im 
personal, 25 ; less objective in fact 
than in theory, 70 ; limitation of, 
34 ; means indeterminate action, 
22 ; mixed character of, 270 ; 
never without affection, 59 ; of 
invidual objects, not primary, 205 : 
of matter, definition of, 8 ; of 


matter, discontinuous, 47 ; of 
things, of utilitarian origin, 206 , 
primary, a discernment of the use 
ful, 206 ; pure, 26, 64 ; pure, an 
intuition of reality, 84 ; pure, a 
system of nascent acts, 74 ; pure, 
its reference to matter, 77 ; pure, 
lowest degree of mind, 297 ; pure, 
theory of, 69 ; reflective, is a circuit, 
126 ; subjectivity of, 75 ; varies 
with cerebral vibrations, 12. 

Perceptive fibres, centrifugal, 125. 

Permanence and change, 260. 

Personality, dilatation of, xiv ; dis 
eases of, 229 ; division of, 229 ; 
present undivided in perception, 

Philosophy, the method of, 239. 

Photography, mental, and subcon- 
sciousness, 101. 

Phrases and words, 148. 

Physical and mental, the, not mere 
duplicates, 300. 

Physical exercise, how learnt, 136. 

Pillon, 105 note, 107 note. 

Place, diversity of , not absolute, 256; 
every, relative, 256. 

Plane, of action, 217 ; of dream, 218. 

Presence and representation, 27. 

Present, at once sensation and move 
ment, 177; definition of, 193; 
ideal, 176 ; ideo-motor, 74 ; is 
consciousness of the body, 177 ; 
is sensori-motor, 177 ; materiality 
of our life, 177 ; real, 176 ; that 
which is acting, 74 ; unique for 
each moment, 177. 

Present moment, how constituted, 

Progress of the idea, 154. 

Psychasthenic disease, how explained, 

Psychic blindness, 108, in ; and 
deafness, 132 ; as a disturbance of 
motor habits, 115 ; does not hinder 
seeing, 161 ; two kinds of, 115. 

Psychic life, the normal, 219 ; funda 
mental law of, 233. 

Psychical states, wider than cerebral 
states, xiii ; have a practical end, 
320 ; unconscious, 181. 

Psychology and metaphysics, relation 
of, xv. 

Pupin, 200 note. 

Pure memory and the memory-image, 

Qualities, in consciousness, and move 
ments in space, 267 ; of different 
orders, share in extensity, 282. 

Quality, and our own duration, 271 ; 
and quantity, 235, 325 ; sensible, 

and space, 282 ; suggests some 
thing other than sensation, 271. 
Quantity and quality, 235, 325. 

Rabier, 106 note. 

Ravaisson, 232 note. 

Reaction, immediate and delayed, 22. 

Reading, a work of divination, 126; 
mechanism of, 125. 

Realism, atomistic, 283 ; Kantian, 
307 ; makes perception an accident, 
16 ; ordinary, 287. 

Realism and idealism, viii, 12, 73; 
their common postulate, 283. 

Realist, the, starts from the universe, 

Realists and idealists, xvi ; views of 
universe, 53. 

Reality, every, has a relation with 
consciousness, 304 ; what it con 
sists in for us, 189. 

Recognition, and attention, 119 ; 
animal, 93 ; attentive,*! 1 8 ; atten 
tive, a circuit, 145 ; automatic, 
118 ; basis of, a motor pheno 
menon, no ; bodily, 109 ; by 
memory-images, 118 ; commonly 
acted before it is thought, 113; 
diseases of, 115 ; erroneous theories 
of, 107 ; essential process of, not 
centripetal but centrifugal, 168 ; 
how constituted, 87 ; in general, 
105 ; intellectual, 145 ; of images, 
86 ; of words, 133 ; process of, 316. 

Recollection, spontaneous, perfect 
from the outset, 95. 

Recollections, disappearance of, 149. 

Region of images, 165. 

Relativity of knowledge, 241. 

Repetition, addressed to the intelli 
gence of the body, 137. 

Representation, at first impersonal, 
43 ; image and thing, vii ; less 
than existence, 27 ; measure of 
possible action, 30 ; of the universe, 
4 ; of things, reflected by free 
dom, 29 ; unconscious, 183 ; use 
of word, 3 note. 

Resemblance, 202* ; and difference, 

Rhythm, of our consciousness, 272. 

Ribot, in, 121, 161, 200 note; his 
law, 150. 

Rieger, 149 note. 

Robertson, 99 note. 

Romberg, 141. 

Rouillard, 201 note. 

Schumann, 100 note. 
Schwartz, 51 note. 
Science, and consciousness, 12 ; 
and universal continuity, 260. 



Self, the normal, 212. 

Sensation, localized and extended, 
180 ; supposed unextended, 51. 

Sensations, order and co-existence of, 
165 ; tactile and visual, 287 ff. 

Sense, good, 198. 

Senses, data of, 259 ; education of, 45. 

Sensori-motor system, 225. 

Serieux, 142 note. 

Shaw, 161 note. 

Shock, effect of, 150, 224. 

Sight, and the perception of exten 
sity, 286. 

Similarity and contiguity, associa 
tions of, 212 ff. 

Skwortzoff, 157 note. 

Sleep, and present reality, 227 ; its 
effect on memory, 199. 

Smith, W. G., 100 note. 

Sommer, 101 note, 151 note, 158 note. 

Soul and body, their relation, x ; 
union of, 234. 

Sounds, and rhythm of movement, 

Soury, 162. 

Space, abstract, 273 ; and sensible 
quality, 282 ; and time, homogen 
eous, not properties of things, 280 ; 
artificial, and extension, 244 ; 
conceived, extensity perceived, 
245 ; homogeneous, a diagram, 
293 ; homogeneous, and concrete 
extensity, 278 ; homogeneous and 
the new hypothesis, 308 ; the 
symbol of fixity, 289 ; the symbol 
of infinite divisibility, 289. 

Spamer, 141 note. 

Specific energy of the nerves, 49. 

Speculation, influenced by habits 
formed in action, xvii. 

Speech, mechanism of, 139 ; to hear 
it intelligently, 153. 

Spencer, 161 note. 

Spirit, an independent reality, 82 ; 
life of, how limited, 233. 

Spirit and matter, reciprocal action 
of, 325 ; transition between, 295. 

Spiritualism, error of in relation to 
matter, 79 ; use of word, 78 note. 

Stadium, The, of Zeno, 252. 

Starr, Allen, in note. 

States, psychical, have a practical 
end, 320 ; strong and weak, 173, 

Strieker, 144. 

Subject and object, their distinction 
and union, 77- 

Subjectivity, a kind of contraction of 
the real, 25 ; of affective states, 52. 

Suggestions, with point de repere, 151. 

Sully, 107 note, 121 note. 

Survival, of the past, 193. 

Symbols, mathematical, express only 
distances, not real movement, 355 

Tension, 327 ; idea of, 237 ; in 
memory, 219, 221 ; psychic, xv. 

Thing, image, and representation, vii. 

Things, and their environment, 278. 

Time and Free Will, 242 note, 268 
note, 286 note. 

Time, homogeneous, an idol of lan 
guage, 274- 

Time and space, homogeneous, not 
properties of things, 280 ; the 
unconscious in relation to, 186. 

Tones, of mental life, 221. 

Toxic drugs, effect of, 228. 

Trajectory, of a moving body, 246. 

Unconscious mental states, 183 ; 

representation, 183. 
Unconscious, the, in relation to time 

and space, 186 ; mechanism of , 72 ; 

problem of, 183. 
Unity, the factitious, 239 ; the living, 


Valentin, 149 note. 

Van der Waals, 263 note. 

Verbal images, discontinuous, 159. 

Verbs, why retained longest, in 

aphasia, 152. 

Veridical hallucinations, 73. 
Vertebrates, nervous system in, 17, 
Virtual image and virtual sensation, 


Visual image, 99. 
Voisin, 141. 
Voluntary, the, and the automatic, 


Vortex rings, 265. 

Ward, James, 106 note, 120 note, 

289 note. 

Wemicke, 149 note, 156 note. 
Wilbrand, 108. 
Winslow, Forbes, 141, 150 note, 204 

Word blindness and deafness, 132 ; 

two kinds of, 133. 
Word deafness, and motor aphasia, 

138 ; with retention of acoustic 

memory, 140. 
Words, and phrases, 148 ; auditory 

memory of, 147- 
World, material, not part of the 

brain, 4. 
Wundt, 121 note, 152 note ; bis 

theory of perception, 164. 
Wysman, 157 note. 

Zeno, paradoxes of, 250 ff. 

Zones of indetermination, 33. 

Bergson, Henri. B 

Matter and memory. ,B4