PERCEPTION
Images as data--Nerves, afferent and efferent, cannot beget images, nor
can the brain give rise to representations--All our perception relative
to action. Denial of this involves the fallacies of Idealism or
of Realism--Perception and knowledge--Physiological data--Zone of
indetermination--"Pure" perception--Memory and Perception.
From the study of Change we are led on to a consideration of the
problems connected with our perception of the external world, which
has its roots in change. These problems have given rise to some very
opposing views--the classic warfare between Realism and Idealism.
Bergson is of neither school, but holds that they each rest on
misconceptions, a wrong emphasis on certain facts. He invites us to
follow him closely while he investigates the problems of Perception in
his own way.
"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 in 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. ... Now of
these images there is ONE which is distinct from all the others, in that
I do not know it only from without by perceptions, but from within by
affections; it is my body." [Footnote: Matter and Memory, p. 1 (Fr.
p. 1).] Further examination shows me that these affections "always
interpose themselves between the excitations from without and the
movement which I am about to execute." [Footnote: Matter and Memory, p. 1
(Fr. p. 1).] Indeed 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 particular images, the type of which is
furnished me by my body." [Footnote: Matter and Memory, p. 3 (Fr. p. 2).]
Reference to physiology shows in the structure of human bodies afferent
nerves which transmit a disturbance to nerve centres, and also efferent
nerves which conduct from other centres movement to the periphery, thus
setting in motion the body in whole or in part. When we make enquiries
from the physiologist or the psychologist with regard to the origin of
these images and representations, we are sometimes told that, as the
centrifugal movements of the nervous system can evoke movement of the
body, so the centripetal movements--at least some of them--give rise to
the representation, mental picture, or perception of the external world.
Yet we must remember that the brain, the nerves, and the disturbance of
the nerves are, after all, only images among others. So it is absurd to
state that one image, say the brain, begets the others, for "the brain
is part of the material world, but 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 disturbances
which are parts of it. Suppose, on the contrary, that these two images,
the brain and the cerebral disturbance, vanish; ex hypothesi 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 a contradiction in terms, since the brain is,
by hypothesis, a part of this image." [Footnote: Matter and Memory, p.
4 (Fr. pp. 3-4).] The data of perception are external images, then my
body, and changes brought about by my body in the surrounding images.
The external images transmit movement to my body, it gives back movement
to them. My body or part of my body, i.e., my brain, could not beget a
whole or part of my representation of the external world. "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 representation." [Footnote: Matter and Memory, p. 5 (Fr.
p. 4).] The body, however, is privileged, since it appears to choose
within certain limits certain reactions from possible ones. It exercises
a real influence on other images, deciding which step to take among
several which may be possible. It judges which course is advantageous
or dangerous to itself, by the nature of the images which reach it. The
objects which surround my body reflect its possible action upon
them. All our perception has reference, primarily, to action, not to
speculation.[Footnote: Cf. Creative Evolution, p. 313 (Fr. p. 321).]
The brain centres are concerned with motor reaction rather than with
conscious perception, "the brain is an instrument of action and not
of representation." [Footnote: Matter and Memory, p. 83 (Fr. p.
69).] Therefore, in the study of the problems of perception, the
starting-point should be action and not sensation. All the confusions,
inconsistencies and absurdities of statement, made in regard to
our knowledge of the external world, have here their origin. Many
philosophers and psychologists "show us a brain, analogous in its
essence to the rest of the material universe, consequently an image, if
the universe is an image. Then, since they want the internal movements
of this brain to create or determine the representation of the whole
material world--an image infinitely greater than that of the cerebral
vibrations--they maintain that these molecular 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 a 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 incomprehensible
action of this formless matter upon this matterless thought." [Footnote:
Matter and Memory, p. 9 (Fr. pp. 7-8).]
The problem at issue between Realists and Idealists turns on the fact
that there are two systems of images in existence. "Here is a system of
images which I term 'my perception of the universe,' and which may be
entirely altered by a very slight change in the privileged image--my
body. This image occupies the centre. By it all the 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 proportion to the cause; this
is what I term the 'universe.'" [Footnote: Matter and Memory, p. 12 (Fr.
p. 10).] The question is, "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?" [Footnote: Matter and Memory, p. 13
(Fr. p. 11).] We may style one the system of science, the other the
system of consciousness. Now, Realism and Idealism are both incapable
of explaining why there are two such systems at all. Subjective
Idealism derives the system of science from that of consciousness, while
materialistic Realism derives the system of consciousness from that of
science. They have, however, this common meeting-place, that they both
regard Perception as speculative in character--for each of them "to
perceive" is to "know." Now this is just the postulate which Bergson
disputes. The office of perception, according to him, is to give us,
not knowledge, but the conditions necessary for action.[Footnote: Notre
croyance a la loi de causalite (Revue de metaphysique et de morale,
1900), p. 658.] A little examination shows us that distance stands for
the degree in which other bodies are protected, as it were, against the
action of my body against them, and equally too for the degree in which
my body is protected from them.[Footnote: Le Souvenir du present et
la fausse reconnaissance in L'Energie spirituelle, pp. 117-161
(Mind-Energy), or Revue philosophique, 1908, pp. 561-593.] Perception
is utilitarian in character and has reference to bodily action, and
we detach from all the images coming to us those which interest us
practically.
Bergson then examines the physiological aspects of the perceptual
process. Beginning with reflex actions and the development of the
nervous system, he goes on to discuss the functions of the spinal cord
and the brain. He finds in regard to these last two that "there is 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 movements the stimulation
received, the brain prolongs 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 co-ordinate, or to inhibit movements.[Footnote: Matter
and Memory, pp. 10-11 (Fr. p. 9).] As we rise in the organic series
we find a division of physiological labour. Nerve cells appear, are
diversified and 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 received 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 prepares 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." [Footnote: Matter and Memory,
pp. 17-18 (Fr. p. 15).] The brain is no more than a kind of central
telephone exchange, its office is to allow communication or to delay
it. It adds nothing to what it receives, it is simply a centre where
perceptions get into touch with motor mechanisms. Sometimes the function
of the brain is to conduct the movement received to a chosen organ of
reaction, while at other times it opens to the movement the totality
of the motor tracks. The brain appears as an instrument of analysis in
regard to movements received by it, but an instrument of selection in
regard to the movements executed. In either case, its office is limited
to the transmission and division of movements. In the lower organisms,
stimulation takes the form of immediate contact. For example, a
jelly-fish feels a danger when anything touches it, and reacts
immediately. The more immediate the reaction has to be, the more it
resembles simple contact. Higher up the scale, sight and hearing enable
the individual to enter into relation with a greater number of objects
and with objects at a distance. This gives rise to an amount of
uncertainty, "a zone of indetermination," where hesitation and choice
come into play. Hence, says Bergson: "Perception is master of space in
the exact measure in which action is master of time." [Footnote: Matter
and Memory, p. 23 (Fr. p. 19).]
In the paper read before the First International Congress of Philosophy
at Paris in 1900, on Our Belief in the Law of Causality,[Footnote: Notre
croyance a la loi de causalite (Revue de metaphysique et de morale,
Sept., 1900, pp. 655-660).] Bergson showed that it has its root in the
co-ordination of our tactile impressions with our visual impressions.
This co-ordination becomes a continuity which generates motor habits or
tendencies to action.
There now comes up for consideration the question as to why this
relation of the organism, to more or less distinct objects, takes
the particular form of conscious perception, and further, why does
everything happen as if this consciousness were born of the internal
movements of the cerebral substance? To answer this question, we must
turn to perceptual processes, as these occur in our everyday life. We
find at once that "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." [Footnote: Matter and Memory, p. 24
(Fr. p. 20).] To such an extent is this true that the immediate data of
perception serve as a sign to bring much more to the mind. Psychological
experiments have conclusively proved that we never actually perceive all
that we imagine to be there. Hence arise illusions, examples of which
may be easily thought of--incorrect proof-reading is one, while another
common one is the mistake of taking one person for another because of
some similarity of dress. What is actually perceived is but a fraction
of what we are looking at and acts normally as a suggestion for the
whole. Now, although it is true that, in practice, Perception and Memory
are never found absolutely separate in their purity, yet it is necessary
to distinguish them from one another absolutely in any investigation
of a psychological nature. If, instead of a perception impregnated
with memory-images, nothing survived from the past, then we should have
"pure" perception, not coloured by anything in the individual's past
history, and so a kind of impersonal perception. However unreal it may
seem, such a perception is at the root of our knowledge of things and
individual accidents are merely grafted on to this impersonal or "pure"
perception. Just because philosophers have overlooked it, and because
they have failed to distinguish it from that which memory contributes to
it, they have regarded Perception as a kind of interior and subjective
vision, differing from Memory only by its greater intensity and not
differing in nature. In reality, however, Perception and Memory differ
fundamentally.
Our conscious perception is just our power of choice, reflected from
things as though by a mirror, so that representation arises from the
omission of that in the totality of matter which has no bearing on our
needs and consequently no interest for us. "There is for images merely
a difference of degree and not of kind between 'being' and 'being
consciously perceived.'" [Footnote: Matter and Memory, p. 30 (Fr. p.
25).] Consciousness--in regard to external perception--is explained by
this indeterminateness and this choice. "But there is in this necessary
poverty of conscious perception, something that is positive, that
foretells spirit; it is, in the etymological sense of the word,
discernment.'" [Footnote: Matter and Memory, p. 31 (Fr. p. 26).] The
chief difficulty in dealing with the problems of Perception, is to
explain "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." [Footnote: Matter and Memory, p. 34 (Fr. p.
29).] We only make an insuperable difficulty if we imagine Perception
to be a kind of photographic view of things, taken from a fixed point
by that special apparatus which is called an organ of perception--a
photograph which would then be developed in the brain-matter by some
unknown chemical and psychical process. "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
perception and cerebral movement are in strict correspondence. The
reciprocal dependence of these two terms is therefore simply due to the
fact that both are functions of a third, which is the indetermination of
the Will." [Footnote: Matter and Memory, p. 35 (Fr. p. 29).]
Moreover, we must recognize that the image is formed and perceived in
the object, not in the brain, even although it would seem that rays
of light coming from a point P are perceived along the path of the
sensori-motor processes in the brain and are afterwards projected into
P. There is not, however, an unextended image which forms itself in
consciousness and then projects itself into the position P. Really,
the point P, and the rays which it emits, together with the retina
and nervous elements affected in the process of perception, all form a
single whole. The point P is an indispensable factor in this whole and
it is really in P and not anywhere else that the image of P is formed
and perceived.[Footnote: Cf. Matter and Memory, p. 37 (Fr p. 31), also
paper entitled Notre croyance a la loi de causalite in the Revue de
metaphysique et de morale, 1900, p. 658.]
In the field of "pure" perception, that is to say, perception
unadulterated by the addition of memory-images, there can arise no image
without an object. "Sensation is essentially due to what is actually
present." [Footnote: Le Souvenir du present et la fausse reconnaissance,
p. 579 of Revue philosophique, Dec., 1908; also L'Energie spirituelle,
p. 141 (Mind-Energy).] Exactly how external stimuli, such as rays of
a certain speed and length, come to give us a certain image, e.g., the
sensation "red" or the sound of "middle C," we shall never understand.
"No trace of the movements themselves can be actually perceived in the
sensation which translates them." [Footnote: Time and Free Will, pp.
34-35 (Fr. p. 26).] We only make trouble by regarding sensations in an
isolated manner and attempting to construct Perception from them. "Our
sensations are to our perceptions, that which the real action of our
body is to its possible or virtual action." [Footnote: Matter and Memory,
p. 58 (Fr. p. 48).] Thus, everything happens as if the external images
were reflected by our body into surrounding space. This is why the
surface of the body, which forms the common limit of the external and
internal, is the only portion of space which is both perceived and
felt. Just as external objects are perceived by me where they are, in
themselves and not in me, so my affective states (e.g. pains--which are
local, unavailing efforts) are experienced where they occur, in my body.
Consider the system of images which we term the "external world." My
body is one of them and around it is grouped the representation, i.e.,
its eventual influence on others. Within it occurs affection, i.e., its
actual effort upon itself. It is because of this distinction between
images and sensations that we affirm that the totality of perceived
images subsists, even if our body disappears, whereas we cannot
annihilate our body without destroying our sensations. In practice,
our "pure" perception is adulterated with affection, as well as with
memories. To understand Perception, however, we must--as previously
insisted upon--study it with reference to action. It is false to suppose
"that perception and sensation exist for their own sake; the philosopher
ascribes to them an entirely speculative function," [Footnote: Matter
and Memory, p. 311 (Fr p. 261).] a proceeding which gives rise to the
fallacies of Realism and Idealism.
It has been said that the choice of perceptions from among images in
general is the effect of a "discernment" which foreshadows spirit. But
to touch the reality of spirit, we must place ourselves at the point
where an individual consciousness continues and retains the past in
a present, enriched by it.[Footnote: See Chapter VI on la duree.
Time--True and False.] Perception we never meet in its pure state; it
is always mingled with memories. The rose has a different scent for you
from that which it has for me, just because the scent of the rose bears
with it all the memories of all the roses we have ever experienced, each
of us individually.[Footnote: Time and Free Will, pp. 161-162 (Fr.
p. 124).] Memory, however mingled with Perception, is nevertheless
fundamentally different in character.[Footnote: Le Souvenir du present
et la fausse reconnaissance, Revue philosophique, Dec., 1908, p. 580;
also L'Effort intellectuel, Revue philosophique, Jan., 1902, p. 23;
L'Energie spirituelle, pp. 141 and 197 (Mind-Energy).] "When we pass
from 'pure' Perception to Memory, we definitely abandon matter for
spirit." [Footnote: Matter and Memory, p. 313 (Fr. p. 263).]