Note 43 — Chapter VIII · OF THE ORIGIN AND DEVELOPMENT OF THE ANIMAL LIFE.

Philosophers and physiologists accord to the touch a great preeminence over the other senses. The senses of seeing, smelling and hearing are, say they, the sources of a thousand illusions. The touch alone is exempt from them, and even rectifies the errors which come from elsewhere; the touch is the sense of reason. It is undoubtedly a delightful prerogative; but let us see if it is incontestable. And first does the touch never deceive us? All children know an experiment which proves the contrary. If we cross two fingers of the same hand, and place in the angular space between their extremities a small body which touches both of them, the touch will give the sensation of two distinct bodies. It is then true that the touch may become a cause of errors; it no doubt serves to rectify those of the other senses, but do not these in their turn often defend us from the errors of the touch? If the sight were not almost constantly in exercise, the errors of touch would be much more numerous; we can judge of them by what we experience when we are in the dark. If we were to take from one man the use of his eyes, and from another that of his hands and the exercise of touch as much as possible, we should see which would be the most embarrassed, which would make the most false judgments.