<h3><SPAN name="RECAPITULATION" id="RECAPITULATION"></SPAN>RECAPITULATION</h3>
<p>I ask permission to reproduce here a communication made by me in
December 1904 to the Société Française de Philosophie. I there set
forth briefly the ideas which I have just developed in this book. This
succinct <i>exposé</i> may be useful as a recapitulation of the argument.</p>
<p><i>Description of Matter.</i>—The physicists who are seeking for a
conception of the Inmost structure of matter in order to explain the
very numerous phenomena they perceive, fancy they can connect them
with other phenomena, less numerous, but of the same order. They thus
consider matter in itself.</p>
<p>We psychologists add to matter something more, viz. the observer. We
consider matter and define it by its relations to our modes of
knowledge—that is to say, by bearing in mind that it is conditioned
by our external perception. These are two different points of view.</p>
<p>In developing our own standpoint, we note that of the outer world we
are acquainted with nothing<span class='pagenum'><SPAN name="Page_257" id="Page_257"></SPAN></span> but our sensations: if we propound this
limit, it is because many observations and experiments show that,
between the external object and ourselves, there is but one
intermediary, the nervous system, and that we only perceive the
modifications which the external object, acting as an excitant,
provokes in this system.</p>
<p>Let us provisionally apply to these modifications the term sensations,
without settling the question of their physical or mental nature.</p>
<p>Other experiments, again, prove to us that our sensations are not
necessarily similar to the objects which excite them; for the quality
of each sensation depends on what is called the specific energy of the
nerve excited. Thus, whether the optic nerve be appealed to by a ray
of light, an electric current, or a mechanical shock, it always gives
the same answer, and this answer is the sensation of light.</p>
<p>It follows that our nervous system itself is only known to us as
regards its structure by the intermediary of sensations, and we are
not otherwise more informed upon its nature than upon that of any
other object whatever.</p>
<p>In the second place, a much more serious consequence is that all our
sensations being equally false, so far as they are copies of the
excitants which provoke them, one has no right to use any of these
sensations to represent to ourselves<span class='pagenum'><SPAN name="Page_258" id="Page_258"></SPAN></span> the inmost structure of matter.
The theories to which many physicists still cling, which consist in
explaining all the modalities of matter by different combinations of
movement, start from false premises. Their error consists in
explaining the whole body of our sensations by certain particular
sensations of the eye, of the touch, and of the muscular sense, in
which analysis discovers the elements and the source of the
representation of motion. Now these particular sensations have no more
objective value than those of the tongue, of the nose, and of the ear;
in so far as they are related to the external excitant of which it is
sought to penetrate the inmost nature, one of them is as radically
false as the other.</p>
<p>It is true that a certain number of persons will think to escape from
our conclusion, because they do not accept our starting point. There
exist, in fact, several systems which propound that the outer world is
known to us directly without the intermediary of a <i>tertium quid</i>,
that is, of sensation. In the first place, the spiritists are
convinced that disembodied souls can remain spectators of terrestrial
life, and, consequently, can perceive it without the interposition of
organs. On the other hand, some German authors have recently
maintained, by rather curious reasoning, that the specific energy of
our nervous system does not transform the excitants, and that our
sensations are the<span class='pagenum'><SPAN name="Page_259" id="Page_259"></SPAN></span> faithful copies of that which causes them.
Finally, various philosophers, Reid, Hamilton, and, in our own days,
the deep and subtle mind of M. Bergson, have proposed to admit that by
direct comprehension we have cognisance of the objects without mystery
and as they are. Let this be admitted. It will change nothing in our
conclusions, and for the following reasons.</p>
<p>We have said that no kind of our sensations—neither the visual, the
tactile, nor the muscular—permits us to represent to ourselves the
inmost structure of matter, because all sensations, without exception,
are false, as copies of material objects. We are now assured that we
are mistaken, and that our sensations are all true—that is to say,
are faithful copies of the objects. If all are true, it comes to the
same thing as if all are false. If all are true, it is impossible to
make any choice among them, to retain only the sensations of sight and
touch, and to use them in the construction of a mechanical theory, to
the exclusion of the others. For it is impossible for us to explain
some by the others. If all are equally true, they all have the same
right to represent the structure of matter, and, as they are
irreconcilable, no theory can be formed from their synthesis.</p>
<p>Let us, consequently, conclude this: whatever hypothesis may be built
up on the relations possibly existing between matter and our
sensa<span class='pagenum'><SPAN name="Page_260" id="Page_260"></SPAN></span>tions, we are forbidden to make a theory of matter in the terms
of our sensations.</p>
<p>That is what I think of matter, understood as the inmost structure of
bodies—of unknowable and metaphysical matter. I shall not speak of it
again; and henceforth when I use the word matter, it will be in quite
a different acceptation—it will be empirical and physical matter,
such as it appears to us in our sensations. It must therefore be
understood that from this moment we change our ground. We leave the
world of <i>noumena</i> and enter that of phenomena.</p>
<p><i>Definition of Mind.</i>—Generally, to define the mind, we oppose the
concept of mind to the concept of matter, with the result that we get
extremely vague images in our thoughts. It is preferable to replace
the concepts by facts, and to proceed to an inventory of all mental
phenomena.</p>
<p>Now, in the course of this inventory, we perceive that we have
continually to do with two orders of elements, which are united in
reality, but which our thought may consider as isolated. One of these
elements is represented by those states which we designate by the name
of sensations, images, emotions, &c.; the other element is the
consciousness of these sensations, the cognition of these images, the
fact of experiencing these emotions. It is, in other words, a special
activity<span class='pagenum'><SPAN name="Page_261" id="Page_261"></SPAN></span> of which these states are the object and, as it were, the
point of application—an activity which consists in perceiving,
judging, comparing, understanding, and willing. To make our inventory
orderly, let us deal with these two elements separately and begin with
the first.</p>
<p>We will first examine sensation: let us put aside that which is the
fact of feeling, and retain that which is felt. Thus defined and
slightly condensed, what is sensation? Until now we have employed the
word in the very vague sense of a <i>tertium quid</i> interposed between
the object and ourselves. Now we have to be more precise, and to
inquire whether sensation is a physical or a mental thing. I need not
tell you that on this point every possible opinion has been held. My
own opinion is that sensation should be considered as a physical
phenomenon; sensation, be it understood, in the sense of impression
felt, and not in that of capacity to feel.</p>
<p>Here are the arguments I invoke for the support of my thesis: in the
first place, popular opinion, which identifies matter with what we
see, and with what we touch—that is to say, with sensation. This
popular opinion represents a primitive attitude, a family possession
which we have the right to retain, so long as it is not proved to us
to be false: next, this remark, that by its mode of apparition at once
unexpected, the revealer of<span class='pagenum'><SPAN name="Page_262" id="Page_262"></SPAN></span> new cognitions, and independent of our
will, as well as by its content, sensation sums up for us all we
understand by matter, physical state, outer world. Colour, form,
extent, position in space, are known to us as sensations only.
Sensation is not a means of knowing these properties of matter, it is
these properties themselves.</p>
<p>What objections can be raised against my conclusion? One has evidently
the right to apply the term psychological to the whole sensation,
taken <i>en bloc</i>, and comprising in itself both impression and
consciousness. The result of this terminology will be that, as we know
nothing except sensations, the physical will remain unknowable, and
the distinction between the physical and the mental will vanish. But
it will eventually be re-established under other names by utilising
the distinction I have made between objects of cognition and acts of
cognition;—a distinction which is not verbal, and results from
observation.</p>
<p>What is not permissible is to declare that sensation is a
psychological phenomenon, and to oppose this phenomenon to physical
reality, as if this latter could be known to us by any other method
than sensation.</p>
<p>If the opinion I uphold be accepted, if we agree to see in sensation,
understood in a certain way, a physical state, it will be easy to
extend this interpretation to a whole series of different phenomena.<span class='pagenum'><SPAN name="Page_263" id="Page_263"></SPAN></span>
To the images, first, which proceed from sensations, since they are
recurring sensations; to the emotions also, which, according to recent
theories, result from the perception of the movements which are
produced in the heart, the vessels, and the muscles; and finally, to
effort, whether of will or of attention, which is constituted by the
muscular sensations perceived, and consequently also results from
corporeal states. The consequences must be clearly remarked. To admit
that sensation is a physical state, is to admit, by that very fact,
that the image, idea, emotion, and effort—all those manifestations
generally ascribed to the mind alone—are also physical states.</p>
<p>What, then, is the mind? And what share remains to it in all these
phenomena, from which it seems we are endeavouring to oust it? The
mind is in that special activity which is engaged in sensation, image,
idea, emotion, and effort. For a sensation to be produced; there must
be, as I said a little time ago, two elements: the something felt—a
tree, a house, an animal, a titillation, an odour,—and also the fact
of feeling this something, the consciousness of it, the judgment
passed on it, the reasoning applied to it—in other terms, the
categories which comprehend it. From this point of view, the dualism
contained in sensation is clearly expressed. Sensation as a thing<span class='pagenum'><SPAN name="Page_264" id="Page_264"></SPAN></span>
felt, that is, the physical part, or matter; sensation as the fact of
feeling or of judging, that is, the mind.</p>
<p>Mark the language I use. We say that matter is the something felt; but
we do not say for the sake of symmetry, that the mind is the something
which feels. I have used a more cautious, and, I think, a more just
formula, which places the mind in the fact of feeling. Let me repeat
again, at the risk of appearing too subtle: the mind is the act of
consciousness; it is not a subject which has consciousness. For a
subject, let it be noted, a subject which feels, is an object of
cognition—it forms part of the other group of elements, the group of
sensations. In practice we represent by mind a fragment of our own
biography, and by dint of pains we attribute to this fragment the
faculty of having a consciousness; we make it the subject of the
relation subject-object. But this fragment, being constituted of
memories and sensations, does not exactly represent the mind, and does
not correspond to our definition; it would rather represent the mind
sensationalised or materialised.</p>
<p>From this follows the curious consequence that the mind is endowed
with an incomplete existence; it is like form, which can only be
realised by its application to matter of some kind. One may fancy a
sensation continuing to exist, to live<span class='pagenum'><SPAN name="Page_265" id="Page_265"></SPAN></span> and to provoke movements, even
after ceasing to be perceived. Those who are not uncompromising
idealists readily admit this independence of the objects with regard
to our consciousness, but the converse is not true. It is impossible
to understand a consciousness existing without an object, a perception
without a sensation to be perceived, an attention without a point of
application, an empty wish which should have nothing to wish for; in a
word, a spiritual activity acting without matter on which to act, or
more briefly still—mind without matter. Mind and matter are
correlative terms; and, on this point, I firmly believe that Aristotle
was much closer to the truth than many modern thinkers.</p>
<p>I have convinced myself that the definition of mind at which we have
just arrived is, in its exactness and soberness, the only one which
permits psychology to be distinguished from the sciences nearest to
it. You know that it has been discovered in our days that there exists
a great difficulty in effecting this delimitation. The definitions of
psychology hitherto proposed nearly all have the defect of not
agreeing with the one thing defined. Time fails us to review them all,
but I shall point out one at least, because our discussion on this
particular formula will serve as a preparation for taking in hand the
last question that remains to<span class='pagenum'><SPAN name="Page_266" id="Page_266"></SPAN></span> be examined—the relation of the mind
to the body.</p>
<p>According to the definition I am aiming at, psychology would be the
science of internal facts, while the other sciences deal with the
external. Psychology, it has also been said, has as its instrument
introspection, while the natural sciences work with the eye, the
touch, the ear—that is to say, with the senses of extrospection.</p>
<p>To this distinction, I reply that in all sciences there exist but two
things: sensations and the consciousness which accompanies them. A
sensation may belong to the inner or the outer world through
accidental reasons, without any change in its nature; the sensation of
the outer world is the social sensation which we share with our
fellows. If the excitant which provokes it is included in our nervous
system, it is the sensation which becomes individual, hidden to all
except ourselves, and constituting a microcosm by the side of a
macrocosm. What importance can this have, since all the difference
depends on the position occupied by the excitant?</p>
<p>But we are persistently told: there are in reality two ways of
arriving at the cognition of objects—from within and from without.
These two ways are as opposite as the right and wrong side of a stuff.
It is in this sense that psychology is the science of the within and
looks at<span class='pagenum'><SPAN name="Page_267" id="Page_267"></SPAN></span> the wrong side, while the natural sciences reckon, weigh,
and measure the right side. And this is so true, they add, that the
same phenomenon absolutely appears under two forms radically different
from each other according as they are looked at from one or the other
of the two points of view. Every one of our thoughts, they point out
to us, is in correlation with a particular state of our cerebral
matter; our thought is the subjective and mental face, the
corresponding cerebral process is the objective and material face.</p>
<p>Though this dualism is frequently presented as an observed truth, I
think it is possible to show its error. Take an example: I look at the
plain before me, and see a flock of sheep pass through it. At the same
time an observer, armed with a microscope <i>à la</i> Jules Verne, looks
into my brain and observes there a certain molecular dance which
accompanies my visual perception. Thus, on the one hand, is my
representation; on the other, a dynamic state of the nerve cells. This
is what constitutes the right and the wrong sides of the stuff. We are
told, "See how little resemblance there is in this; a representation
is a psychical, and a movement of molecules a material, thing."</p>
<p>But I, on the contrary, think there is a great resemblance. When I see
the flock passing, I have a visual perception. The observer who, by
the hypothesis, is at that moment looking into<span class='pagenum'><SPAN name="Page_268" id="Page_268"></SPAN></span> my brain, also
experiences a visual perception. Granted, they are not the same
perception. How could they be the same? I am looking at the sheep, he
is looking at the interior of my brain; it is not astonishing that,
looking at objects so different, we should receive images also very
different. But, notwithstanding their difference of object—that is,
of content—there are here two visual perceptions composed in the same
way; and I do not see by what right it can be said that one represents
a material, the other a physical, phenomenon. In reality, each of
these perceptions has a two-fold and psycho-physical value—physical
in regard to the object to which it applies, and psychical inasmuch as
it is an act of perception, that is to say, of consciousness. For one
is just as much psychical as the other, and as much material, for a
flock of sheep is as material a thing as is my brain. If we keep this
conclusion in our minds, when we come to make a critical examination
of certain philosophical systems, we shall easily see the mistake they
make.</p>
<p>Spiritualism<SPAN name="FNanchor_51_51" id="FNanchor_51_51"></SPAN><SPAN href="#Footnote_51_51" class="fnanchor">[51]</SPAN> rests on the conception that the mind can subsist and
work in total independence of any tie to matter. It is true that, in
details, spiritualists make some modification in this absolute
principle in order to explain the perceptions of the senses and the
execution of the orders of the <span class='pagenum'><SPAN name="Page_269" id="Page_269"></SPAN></span>will; but the duality, the
independence, and the autonomy of the soul and the body remain, in any
case, the peculiar dogma of the system. This dogma appears to me
utterly false; the mind cannot exist without matter to which it is
applied; and to the principle of heterogeneity, so often invoked to
forbid all commerce between the two substances, I reply by appealing
to intuition, which shows us the consciousness and its different
forms, comparison, judgment, and reasoning, so closely connected with
sensation that they cannot be imagined as existing with an isolated
life.</p>
<p>Materialism, we know, argues quite differently; it imagines that a
particular state of the nerve centres has the virtue of generating a
psychical phenomenon, which represents, according to various
metaphors, property, function, effect, and even secretion. Critics
have often asked how, with matter in motion, a phenomenon of thought
could be explained or fabricated. It is very probable that those who
admit this material genesis of thought, represent it to themselves
under the form of something subtle, like an electric spark, a puff of
wind, a will-of-the-wisp, or an alcoholic flame. Materialists are not
alone responsible for these inadequate metaphors, which proceed from a
metaphysics constructed of concepts. Let us recollect exactly what a
psychical phe<span class='pagenum'><SPAN name="Page_270" id="Page_270"></SPAN></span>nomenon is. Let us banish the will-o'-the-wisps, replace
them by a precise instance, and return to the visual perception we
took as an example a little while back: without intending a pun,
"revenons à nos moutons." These sheep which I see in the plain are as
material, as real, as the cerebral movement which accompanies my
perception. How, then, is it possible that this cerebral movement, a
primary material fact, should engender this secondary material fact,
this collection of complicated beings which form a flock?</p>
<p>Before going any further, let us invite another philosophical system
to take a place within the circle of our discussion; for the same
answer will suffice for it as well as for the preceding one, and it
will be as well to deal with both at once. This new system,
parallelism, in great favour at the present day, appears to me to be a
materialism perfected especially in the direction of caution. To
escape the mystery of the genesis of the mind from matter, this new
system places them parallel to each other and side by side, we might
almost say experimentally, so much do parallelists try to avoid
talking metaphysics. But their position is untenable, and they
likewise are the victims of the mirage of concepts; for they consider
the mental as capable of being parallel to the physical without
mingling with it, and of subsisting by itself and with a life of its
own. Such a hypothesis is only<span class='pagenum'><SPAN name="Page_271" id="Page_271"></SPAN></span> possible by reason of the insufficient
definition given to the mind. If it be recognised that the mind has an
incomplete existence and is only realised by its incarnation in
matter, the figure which is the basis of parallelism becomes
indefensible. There is no longer on the one hand the physical, and on
the other the mental, but on one side the physical and the mental
combined, and on the other the same combination; which amounts to
saying that the two faces to a reality, which it was thought had been
made out to be so distinct, are identical. There are not two faces,
but one face; and the monism, which certain metaphysicians struggle to
arrive at by a mysterious reconciliation of the phenomenal duality
within the unity of the noumenon, need not be sought so far afield,
since we already discover it in the phenomenon itself.</p>
<p>The criticisms I have just pointed out to you, only too briefly, are
to be found in several philosophers, confusedly in Berkeley, and with
more precision in M. Bergson's book on <i>Matière et Mémoire</i>. The
latter author, remarking that our brain and the outer world are to us
images of the same order, refuses to admit that the brain, which is
only a very small part of these images, can explain and contain the
other and much larger part, which comprises the vast universe. This
would amount to saying that the whole is comprised in the part.<span class='pagenum'><SPAN name="Page_272" id="Page_272"></SPAN></span> I
believe that this objection is analogous to the one just stated with
less ingenuity.</p>
<p>It is interesting to see how M. Bergson gets out of the difficulty
which he himself raised. Being unwilling to bring forth from the
molecular movement of the brain the representation of the world, or to
superpose the representation on this movement as in the parallelist
hypothesis, he has arrived at a theory, very ingenious but rather
obscure, which consists in placing the image of the world outside the
brain, this latter being reduced to a motor organ which executes the
orders of the mind.</p>
<p>We thus have four philosophical theories, which, while trying to
reconcile mind with matter, give to the representation a different
position in regard to cerebral action. The spiritualist asserts the
complete independence of the representation in relation to cerebral
movement; the materialist places it after, the parallelist by the side
of, the cerebral movement; M. Bergson puts it in front.</p>
<p>I must confess that the last of these systems, that of M. Bergson,
presents many difficulties. As he does not localise the mind in the
body, he is obliged to place our perception—that is to say, a part of
ourselves—in the objects perceived; for example, in the stars when we
are looking at them. The memory is lodged in distant planes of
consciousness which are not otherwise defined. We<span class='pagenum'><SPAN name="Page_273" id="Page_273"></SPAN></span> understand with
difficulty these emigrations, these crumblings into morsels of our
mind. This would not matter if our author did not go so far as to
maintain that the sensory nerves of the brain are not sensory nerves,
and that the severance of them does not suppress sensations, but
simply the motor efforts of these sensations. All the physiologist in
me protests against the rashness of these interpretations.</p>
<p>The principal difficulties of the problem of the union between the
mind and the body proceed from the two following facts, which seem
incompatible. On the one hand, our thought is conditioned by a certain
intra-cerebral movement of molecules and atoms; and, on the other
hand, this same thought has no consciousness of this molecular
movement. It does not know the path of the wave in our nerves; it does
not suspect, for example, that the image of the objects is reversed in
the retina, or that the excitements of the right eye for the most part
go into the left hemisphere. In a word, it is no anatomist. It is a
very curious thing that our consciousness enters into relation only
with the extra-cerebral, the external objects, and the superficies of
our bodies.</p>
<p>From this, this exact question suggests itself: a molecular wave must
come as far as our visual cerebral centre for us to have the
perception of the object before our eyes; how is it that our
con<span class='pagenum'><SPAN name="Page_274" id="Page_274"></SPAN></span>sciousness is unaware of this physiological event from which it
depends, and is borne towards the distant object as if it sprang forth
outside our nervous system?</p>
<p>Let us first remark, that if we do not perceive this wave, yet it must
contain all we know of the external object, for it is evident that we
only know of it that part of its properties which it transmits to our
nerves and our nerve centres. All the known substance of the external
object is, then, implied in this vibration; it is there, but it is not
there by itself. The vibration is the work of two collaborators; it
expresses at once the nature of the object which provokes it, and the
nature of the nerve apparatus which transports it, as the furrow
traced in the wax of the phonograph implies the joint action of an
aërial vibration with a stylus, a cylinder, and, a clock-work
apparatus.</p>
<p>I therefore suppose—and this is, I say it plainly, but an
hypothesis—that if the nervous vibration so little resembles the
external excitant which generates it, it is because the factor nervous
system superadds its effect to the factor excitant. Let us imagine,
now, that we have managed to separate these two effects, and we shall
understand that then the nervous event so analysed might resemble only
the object, or only the nervous system. Now, of these two effects, one
is constant, that one which represents the action of the nervous
system;<span class='pagenum'><SPAN name="Page_275" id="Page_275"></SPAN></span> there is another which varies with each new perception, and
even with every moment of the same perception—that is to say, the
object. It is not impossible to understand that the consciousness
remains deaf to the constant and sensitive to the variable element.
There is a law of consciousness which has often been described, and
fresh applications of which are met with daily: this is, that the
consciousness only maintains itself by change, whether this change
results from the exterior by impressions received, or is produced from
the interior by movements of the attention. Let us here apply this
empirical law, and admit that it contains a first principle. It will
then be possible for us to understand that the consciousness formed
into a dialyser of the undulation may reject that constant element
which expresses the contribution of the nervous system, and may lay
bare the variable element which corresponds to the object: so that an
intestinal movement of the cerebral substance, brought to light by
this analytical consciousness, may become the perception of an object.
By accepting this hypothesis, we restore to the sensory nerves and to
the encephalic centres their property of being the substrata of
representation, and avoid the objection made above against materialism
and parallelism, that they did not explain how a cerebral movement,
which is material, can engender the perception of an object which
differs<span class='pagenum'><SPAN name="Page_276" id="Page_276"></SPAN></span> greatly from it and is yet as material as the movement
itself. There is not here, properly speaking, either generation,
transformation, or metamorphosis. The object to be perceived is
contained in the nerve current. It is, as it were, rolled up in it;
and it must be made to go forth from the wave to be seen. This last is
the work of the consciousness.</p>
<div style="break-after:column;"></div><br />