DEFINITION OF THE IMAGE
Going on with our inventory, after sensations come images, ideas, and
concepts; in fact, quite a collection of phenomena, which, are
generally considered as essentially psychological.
So long as one does not carefully analyse the value of ideas, one
remains under the impression that ideas form a world apart, which is
sharply distinguished from the physical world, and behaves towards it
as an antithesis. For is not conception the contrary of perception?
and is not the ideal in opposition to reality?
Thoughts have some characteristics of fancy, of freedom, even of
unreality, which are wanting to the prosaicness of heavy material
things. Thoughts sport with the relations of time and space; they fly
in a moment across the gulf between the most distant objects; they
travel back up the course of time; they bring near to us events
centuries away; they conceive objects which are unreal; they imagine
combinations which upset all physical laws, and, further, these
conceptions remain invisible to others as well as to ourselves. They
are outside the grip of reality, and constitute a world which becomes,
for any one with the smallest imagination, as great and as important
as the world called real. One may call in evidence the poets,
novelists, artists, and the dreamers of all kinds. When life becomes
too hard for us, we fly to the ideal world, there to seek
forgetfulness or compensation.
It is, therefore, easy to understand, that it should have been
proposed to carry into ideation the dichotomy between the physical and
the moral. Many excellent authors have made the domain of the mind
begin in the ideal. Matter is that which does not think. Descartes, in
his _Discours de la Méthode_ (4th part), remarking that he may pretend
"not to have a body, and that there is no world or place in which he
exists, but that he cannot pretend that he does not think," concludes
by saying that the mind is "a substance, all whose essence or nature
is merely to think, and which has no need of either place or any other
material thing, in order to exist;" in short, that "the soul is
absolutely distinct from the body."[19]
Let us, then, examine in what measure this separation between
perception and ideation can be legitimately established. If we accept
this separation, we must abandon the distinction I proposed between
acts and objects of cognition, or, at least, admit that this
distinction does not correspond to that between the physical and the
moral, since thoughts, images, recollections, and even the most
abstract conceptions, all constitute, in a certain sense, objects of
cognition. They are phenomena which, when analysed, are clearly
composed of two parts, an object and a cognition. Their logical
composition is, indeed, that of an external perception, and there is
in ideation exactly the same duality as in sensation. Consequently, if
we maintain the above distinction as a principle of classification for
all knowable phenomena, we shall be obliged to assign the same
position to ideas as to sensations.
The principal difference we notice between sensation and idea is, it
would seem, the character of unreality in the last named; but this
opposition has not the significance we imagine. Our mental vision
only assumes this wholly special character of unreality under
conditions in which it is unable to harmonise with the real vision.
Taine has well described the phases of the reduction of the image by
sensation: it is at the moment when it receives the shock of an image
which contradicts it, that the image appears as illusory.[20] Let us
suppose that we are sitting down dreaming and watching the passing by
of our images. If, at this moment, a sudden noise calls us back to
reality, the whole of our mental phantasmagoria disappears as if by
the wave of a magic wand, and it is by thus vanishing that the image
shows its falsity. It is false because it does not accord with the
present reality.
But, when we do not notice a disagreement between these two modes of
cognition, both alike give us the impression of reality. If I evoke a
reminiscence and dwell attentively on the details, I have the
impression that I am in face of the reality itself. "I feel as if I
were there still," is a common saying; and, among the recollections I
evoke, there are some which give me the same certitude as the
perception of the moment. Certain witnesses would write their
depositions with their blood. One does not see this every day; but
still one does see it.
Further, there are thousands of circumstances where the ideation is
neither in conflict with the perception nor isolated from it, but in
logical continuity with it. This continuity must even be considered as
the normal condition. We think in the direction of that which we
perceive. The image seems to prepare the adaptation of the individual
to his surroundings; it creates the foresight, the preparation of the
means, and, in a word, everything which constitutes for us a final
cause. Now, it is very necessary that the image appear real to be
usefully the substitute of the sensation past or to come.
Let us establish one thing more. Acting as a substitute, the image not
only appears as real as the sensation, it appears to be of the same
nature; and the proof is that they are confounded one with the other,
and that those who are not warned of the fact take one for the other.
Every time a body is perceived, as I previously explained, there are
images which affix themselves to the sensation unnoticed. We think we
perceive when we are really remembering or imagining. This addition of
the image to the sensation is not a petty and insignificant accessory;
it forms the major part, perhaps nine-tenths, of perception. Hence
arise the illusions of the senses, which are the result, not of
sensations but of ideas. From this also comes the difficulty of
knowing exactly what, under certain circumstances, is observation or
perception, where the fact perceived ends, and where conjecture
begins. Once acquainted with all these possibilities of errors, how
can we suppose a radical separation between the sensation and the
image?
Examined more closely, images appear to us to be divisible into as
many kinds as sensations: visual images correspond to visual
sensations, tactile to tactile, and so on with all the senses.
That which we experience in the form of sensation, we can experience
over again in the form of image, and the repetition, generally weaker
in intensity and poorer in details, may, under certain favourable
circumstances, acquire an exceptional intensity, and even equal
reality: as is shown by hallucinations. Here, certainly, are very
sound reasons for acknowledging that the images which are at the
bottom of our thoughts, and form the object of them, are the
repetition, the modification, the transposition, the analysis or the
synthesis of sensations experienced in the past, and possessing, in
consequence, all the characteristics of bodily states. I believe that
there is neither more nor less spirituality in the idea than in the
sensation. That which forms its spirituality is the implied act of
cognition; but its object is material.
I foresee a final objection: I shall be told that even when the
unreality of the image is not the rule, and appears only under certain
circumstances, it nevertheless exists. This is an important fact. It
has been argued from the unreality of dreams and hallucinations in
which we give a body to our ideas, that we do not in reality perceive
external bodies, but simply psychical states and modifications of our
souls. If our ideas consist--according to the hypothesis I uphold--in
physical impressions which are felt, we shall be told that these
particular impressions must participate in the nature of everything
physical; that they are real, and always real; that they cannot be
unreal, fictitious, and mendacious, and that, consequently, the
fictitious character of ideation becomes inexplicable.
Two words of answer are necessary to this curious argument, which is
nothing less than an effort to define the mental by the unreal, and to
suppose that an appearance cannot be physical. No doubt, we say, every
image, fantastical as it may seem as signification, is real in a
certain sense, since it is the perception of a physical impression;
but this physical nature of images does not prevent our making a
distinction between true and false images. To take an analogous
example: we are given a sheet of proofs to correct, we delete certain
redundant letters, and, although they are printed with the same type
as the other letters, we have the right to say they are false. Again,
in a musical air, we may hear a false note, though it is as real as
the others, since it has been played. This distinction between reality
and truth ought to be likewise applied to mental images. All are real,
but some are false. They are false when they do not accord with the
whole reality; they are true when they agree; and every image is
partly false because, being an image, it does not wholly accord with
the actual perceptions. It creates a belief in a perception which does
not occur; and by developing these ideas we could easily demonstrate
how many degrees of falsehood there are.
Physiologically, we may very easily reconcile the falsity of the image
with the physical character of the impression on which it is based.
The image results from a partial cerebral excitement, which sensation
results from an excitement which also acts upon the peripheral sensory
nerves, and corresponds to an external object--an excitant which the
image does not possess. This difference explains how it is that the
image, while resulting from a physical impression, may yet be in a
great number of cases declared false--that is to say, may be
recognised as in contradiction to the perceptions.
To other minds, perhaps, metaphysical reasoning will be more
satisfactory. For those, we propose to make a distinction between two
notions, Existence or Reality, on the one hand, and Truth, on the
other.
Existence or Reality is that of which we have an immediate
apprehension. This apprehension occurs in several ways. In perception,
in the first place. I perceive the reality of my body, of a table, the
sky, the earth, in proportion to my perception of them. They exist,
for if they did not, I could not perceive them. Another way of
understanding reality is conception or thought. However much I may
represent a thing to myself as imaginary, it nevertheless exists in a
certain manner, since I can represent it to myself. I therefore, in
this case, say that it is real or it exists. It is of course
understood, that in these definitions I am going against the ordinary
acceptation of the terms; I am taking the liberty of proposing new
meanings. This reality is, then, perceived in one case and conceived
in the other. Perceptibility or conceivability are, then, the two
forms which reality may assume. But _reality_ is not synonymous with
_truth_; notwithstanding the custom to the contrary, we may well
introduce a difference between these two terms. Reality is that which
is perceived or conceived; truth is that which accords with the whole
of our knowledge. Reality is a function of the senses or of ideation;
truth is a function of reasoning or of the reason.
For cognition to be complete, it requires the aid of all these
functions. And, in fact, what does conception by itself give? It
allows us to see if a thing is capable of representation. This is not
a common-place thing, I will observe in passing; for many things we
name are not capable of representation, and there is often a criticism
to be made; we think we are representing, and we are not. What is
capable of representation exists as a representation, but is it true?
Some philosophers have imagined so, but they are mistaken; what we
succeed in conceiving is alone possible.
Let us now take the Perceptible. Is what one perceives true? Yes, in
most cases it is so in fact; but an isolated perception may be false,
and disturbed by illusions of all kinds. It is all very well to say,
"I see, I touch." There is no certainty through the senses alone in
many circumstances that the truth has been grasped. If I am shown the
spirit of a person I know to be dead, I shall not, notwithstanding the
testimony of my eyes, believe it to be true, for this apparition would
upset all my system of cognitions.
Truth is that which, being deemed conceivable, and being really
perceived, has also the quality of finding its place, its relation,
and its confirmation in the whole mass of cognitions previously
acquired.
These distinctions,[21] if developed, would readily demonstrate that
the advantages of observation are not eclipsed by those of
speculation; and that those of speculation, in their turn, do not
interfere with those of observation. But we have not time to develop
these rules of logic; it will be sufficient to point out their
relation to the question of the reality of mental images. Here are my
conclusions in two words. Physical phenomena and images are always
real, since they are perceived or conceived; what is sometimes wanting
to them, and makes them false, is that they do not accord with the
rest of our cognitions.[22]
Thus, then, are all objections overruled, in my opinion at least. We
can now consider the world of ideas as a physical world; but it is
one of a peculiar nature, which is not, like the other, accessible to
all, and is subject to its own laws, which are laws of association. By
these very different characteristics, it separates itself so sharply
from the outer world that all endeavour to bring the two together
seems shocking; and it is very easy to understand that many minds
should wish to remain faithful to the conception that ideas form a
mental or moral world. No metaphysical reasoning could prevail against
this sentiment, and we must give up the idea of destroying it. But we
think we have shown that idea, like sensation, comprises at the same
time the physical and the mental.
FOOTNOTES:
[Footnote 19: Let me say, in passing, that this separation that
DESCARTES thinks he can establish between perception and ideation, is
only conceivable on condition that it be not too closely examined, and
that no exact definition of ideation be given. If we remark, in fact,
that all thought is a reproduction, in some degree, of a sensation, we
arrive at this conclusion: that a thought operated by a soul distinct
from the body would be a thought completely void and without object,
it would be the thought of nothingness. It is not, therefore,
conceivable. Consequently the criterion, already so dangerous, which
DESCARTES constantly employs--to wit: that what we clearly conceive is
true--cannot apply to thought, if we take the trouble to analyse it
and to replace a purely verbal conception by intuition.]
[Footnote 20: I somewhat regret that TAINE fell into the common-place
idea of the opposition of the brain and thought; he took up again this
old idea without endeavouring to analyse it, and only made it his own
by the ornamentation of his style. And as his was a mind of powerful
systematisation, the error which he committed led him into much wider
consequences than the error of a more common mind would have done.]
[Footnote 21: I have just come across them again in an ingenious note
of C. L. HERRICK: _The Logical and Psychological Distinction between
the True and the Real_ (_Psych. Rev._, May 1904). I entirely agree
with this author. But it is not he who exercised a suggestion over my
mind; it was M. BERGSON. See _Matière et Mémoire_, p. 159.]
[Footnote 22: In order to remain brief, I have not thought fit to
allude in the text to a question of metaphysics which closely depends
on the one broached by me: the existence of an outer world.
Philosophers who define sensation as a modality of our Ego are much
embarrassed later in demonstrating the existence of an outer world.
Having first admitted that our perception of it is illusory, since,
when we think we perceive this world, we have simply the feeling of
the modalities of our Ego, they find themselves powerless to
demonstrate that this illusion corresponds to a truth, and invoke in
despair, for the purpose of their demonstration, instinct,
hallucination, or some _a priori_ law of the mind. The position we
have taken in the discussion is far more simple. Since every sensation
is a fragment of matter perceived by a mind, the aggregate of
sensations constitutes the aggregate of matter. There is in this no
deceptive appearance, and consequently no need to prove a reality
distinct from appearances. As to the argument drawn from dreams and
hallucinations which might be brought against this, I have shown how
it is set aside by a distinction between perceptibility and truth. It
is no longer a matter of perception, but of reasoning. In other words,
all that we see, even in dreams, is real, but is not in its due
place.]