Physiological Researches on Life and Death

by Xavier Bichat

In fact, this sense is especially destined to confirm the notions which are acquired by the others, and to rectify them, for the latter are frequently illusory—the touch is always the agent of truth.[43] In attributing to the touch such use, nature has submitted it directly to the will; light, odours, and sounds affect their respective organs independently of the will.

The exercise of the other senses precedes that of the touch, they are the occasion of it. If a man were born without sight, hearing, smell, or taste, can we conceive in what way, he would be possessed of the sense of touch?

The fœtus resembles such a man; it possesses wherewithal to exercise the touch in its hands, which are already developed, and in the parietes of the matrix. Nevertheless the fœtus is never in action, because in seeing, in hearing, in smelling, and in tasting nothing, it is not disposed to exercise the touch in any way. Its members are little better than what to the tree are its branches, which do not transmit the impression of the bodies, with which they are entangled.

I shall here notice a great difference between the tact and the touch; they were formerly confounded by physiologists; the impressions of the latter are always directed by the will, those of the former do not depend on it. We shall conclude that the portion of the animal life which constitutes sensation, does not exist in the fœtus.

This nullity of action in the senses supposes the same deficiency of action in the nerves, which belong to them, and in that of the brain from whence they issue; for the business of the former is to transmit, of the latter to receive. Now without objects for transmission and reception, the two functions cannot have place.

From perception are immediately derived the memory and imagination; from these the powers of the judgment and the will. All this series of faculties then has not had a beginning in the fœtus, because the fœtus has not perceived, or had sensation. The brain exists in a state of expectation, it possesses all that is requisite for action. It does not want excitability, but stimulus. The first division of the animal life in consequence, or that, which relates to the action of exterior bodies, on the animal, has scarcely an outline in the fœtus. Let us examine whether the same be true of the second division of the animal life, or that which relates to the reaction of the living body.

II. Locomotion exists, but belongs in the fœtus to the organic life.

When we see the strict connexion which exists in animals, between sensation and their voluntary efforts, we might be induced to believe, that voluntary motion increases or diminishes with the increase or diminution of sentiment; for as sentiment furnishes out the materials of the will, when it does not exist, volition cannot exist: from induction to induction, it might thus be proved that in the fœtus the muscles must be totally inactive.

Nevertheless the fœtus moves, and sometimes even very strong shocks are the result of its motions. The reason why it does not produce sound, is because the medium for the production of sound is wanting. But how can we ally the inertia of the first part of the animal life with the activity of the second. It is thus.