But let us come back to our tree or our ox. This ox can enter us in one
of two ways. First, partly, but really, in the form of food. What we
absorb of it in that way cannot, evidently, be known as ox. It reaches
our knowledge only through its effects--strength, health, gaiety,
activity, depression. Even were this absorption total in the case of a
small animal, digestible in all its parts, the result, from the point
of view of immediate knowledge, would be the same, since the object
becomes resolved into elements which render its form unknowable.
The other manner--that which brings into play the external senses--will
make us know the ox, in appearance as such, in reality as image of an
ox. What is the true value of this knowledge? We must here return to
this question, in order to enter more easily upon the second part of
this essay.
Truth has been very seriously defined as conformity of the
representation of an object with this object itself. But that solves
nothing. What is the object itself, since we can know it only as
representation? It is useless to carry the discussion further. We shall
turn indefinitely around the fortress of idealism, without ever finding
an opening, or any weak point. We shall enter it never, no argument
serving as a bomb against its solid walls.
However, we must consider carefully. Having thoroughly reflected, we
shall ask if this fortress be real, or if, on the contrary, it be not,
perhaps, a representation without object, a pure phantom, like those
sunken cities whose bells still ring for great festivals, but are heard
only by those who believe in their mysterious life. This doubt will
lead us to re-examine the reasoning of Berkeley and of Kant, and see
if it be well constructed. Does it start from the senses to reach the
mind? Or may it not, perchance, be one of those mental conceptions
which fall back upon the senses like an avalanche, freezing and
smothering them?
How have the senses been formed? Such is the question. Has there
always been an opposition between the ego and the non-ego? There is
nothing in the intelligence that has not first been in the senses.
By intelligence, we must in this philosophic dictum, due to Locke,
understand the psychologic consciousness. Let us leave aside the
consciousness, which can only serve to complicate the problem.
Consciousness is a phenomenon of secondary order and of an entirely
sentimental utility, if it be restricted to man; commonplace and of
pure reflex, if extended to all sensible matter. Let us consider this
matter in perhaps its humblest manifestations, taking account only of
the actions and reactions, exactly as we might observe the influence
of heat, of light, or of cold on milk, wine or water. In living matter
there will, however, be something more--the decomposition will be
compensated by assimilation, and if the assimilation be abundant, there
will be generation. Other forms, resembling the first, will detach
themselves from the matrix form. This represents life essentially,
a living being, a being limited in duration by the very fact of its
growth, which constitutes an effort and a loss. Let us consider a being
whose senses are not differentiated, and let us see how it gets on with
the rest of the world, how it knows it.
The amoeba has no exterior senses. It is an almost homogeneous mass,
and yet it is sensible to almost the same sensorial impressions as the
highest mammal. It feeds (smell and taste); it moves (sense of space,
touch); it is sensible to light, at least to certain rays (sight);
its environment being in perpetual movement, ceaselessly traversed by
sonorous waves, it doubtless reacts to these vibrations (hearing).
Perhaps, even, it possesses, without special organs, senses which we
lack, and which we recover only by study and analysis, such as the
chemical sense, which judges the composition of a body, declares it
assimilable or counsels its rejection. The exercise of all these senses
denotes, first of all, a very long heredity. They have, doubtless, been
acquired successively only, unless, the absence of one of them being
capable of causing death, their presence is the strict consequence
of the life of this humble beast. But it is useless to construct any
hypotheses on the subject. It is enough to keep to the fact, and this
fact is the existence of a being without differentiated organs, that is
to say, a being all of whose parts are equally adapted to react against
every external excitation.
Why these reactions? They are one of the conditions of life. But could
not life be conceived without them? It is possible. It is a question of
environment. If the amoeba's environment were homogeneous and calm, if
it were of a constant temperature and luminosity, if it furnished an
abundance of proper nourishment, if, in a word, the animal dwelt in an
alimentary bath, no reactions would be necessary, and its only movement
would be to open its pores for food, to reject the excess of this food,
to divide itself, when swollen, into two amoebas. Why, then, does it
possess all these senses which, though unorganized, are perfectly
real? Because the environment obliges it to have them, because of its
instability. The senses, whether differentiated, or spread over the
entire surface of a living form, are the creation of the environment
which--light, sound, material exteriority, odours, etc.--acts in
accordance with different discontinuous manifestations. Constant or
continuous, they would be without effect. Discontinuous, they make
themselves felt. Discontinuous light has created the eye, just as the
drop of water creates a hole in granite.
A being, whatever it may be, whether vague and almost amorphous or
clearly defined, is not isolated in the universal vital environment.
It is the molecule of a diapason. It vibrates, not of its own accord,
but in obedience to a general movement. The living cell, itself in
internal movement and subjected to all the reactions of external
movement, perceives this movement doubtless as an unique impression
only. But when several cells come together and live in permanent
contact, the impressions of external movement begin to be perceived as
differentiated. Is this then necessary? Do there then already exist
luminous vibrations, different from sonorous vibrations? Assuredly,
since otherwise the sensorial differentiation would be inexplicable,
being useless. The union of several cells permits the animal to
divide its work of perception, and to present to each perceptible
manifestation an organ or, at least, the sketch of an organ,
appropriate to receive it.
It would be possible, it is true, from the idealistic point of view,
to suppose that the senses are a creation of the individual, an
enhancement of his own life, and that he differentiates, on his own
initiative, his cinematic impression. This would be a phenomenon of
spontaneous analytic creation, the analyzing instrument existing prior
to the matter analyzed, or even, for exasperated idealists, creating
this matter according to determinate needs, once and for all, by its
own physiology. It would then be a property of organized living matter
to fabricate senses for itself, and to diversify, by this means, its
own life. This point of view is not easy to admit for several reasons,
purely physical.
First, if this sensorial differentiation were a faculty of living
matter, it would not be observed to be limited in its powers, as it
is. Even admitting certain senses unknown to man, such as the chemical
sense, the electric sense, the sense of orientation (extremely
doubtful), it is still seen that the number of senses is very limited.
But, far more important, the fundamental senses are found to be
identical among the majority of the higher species, vertebrates and
insects, with very few exceptions. The moment the animal arrives at
sensorial differentiation, this differentiation occurs in response to
the manifestations of matter.
The senses should, then, correspond to external realities. They have
been created, not by the perceiving being, but by the perceptible
environment. It is the light that has created the eye, just as, in
our houses, it has created the windows. Where there is no light,
fish become blind. This is perhaps the direct proof, for if light is
the creation of the eye, this creation can occur at the bottom of
the sea quite as well as on the surface of the earth. Another proof:
these same fish, having become blind, but still requiring a luminous
habitat, create for themselves in the night of the abysses, not eyes,
but apparatus directly productive of light; and this artificial light
creates anew the atrophied eye. The senses are then clearly the product
of the environment. That is all they can do, moreover, their utility
being nil, if the environment is not perceptible. It might still be
objected that it is the nervous system which, having intuition of an
environment to be perceived, creates for itself organs adapted to this
perception. But this is merely begging the question; for, either the
nervous system has knowledge of the external environment, which means
that it already has senses, or else it has no senses, and thus can
have no knowledge. A more serious objection would be that, sensorial
aptitude being a property of the nervous system, it would afterwards
create for itself organs in order to perceive more distinctly, and
clearly differentiated, the various natural phenomena. This view would
explain up to a certain point the creation of sensorial organs, but
not the existence of the senses themselves as sensitive power. It is,
moreover, certain that the nervous system acts rather by tyrannizing
the organs at its disposal, than by seeking to modify these organs or
to create new ones. It is a power which evidently exceeds the limits
of its capacity. It has, on the contrary, devolved upon the external
phenomena which, in acting mechanically on the living matter, produce
in it local modifications. The organs of the senses seem to be nothing
other than surfaces sensitized by the very agents which, once their
work is done, will reflect in them their particular physiognomy. The
eye--let us take once more this example, and repeat it--is a creation
of light.
Since they are themselves the work of the principal general
phenomena, the senses ought then to agree exactly--allowing for
approximation--with the very nature which has created them. The
luminous environment is not, in this case, a dream, but a reality, and
a reality existing prior to the eye which perceives it; and, since the
eye is the very product of light, objects situated in this luminous
environment should be perceived by it as an exact image, just as the
drill which creates a hole, creates it strictly to its size, its form,
its image. Bacon said that the senses are holes. Here this is only a
metaphor.