Oysters, it is said, have two senses; moles four; all other animals, like man, five. Some people contend for a sixth, but it is evident that the voluptuous sensation to which they allude is reducible to that of touch; and that five senses are our lot. It is impossible for us to imagine anything beyond them, or to desire out of their range.

It may be, that in other globes the inhabitants possess sensations of which we can form no idea. It is possible that the number of our senses augments from globe to globe, and that an existence with innumerable and perfect senses will be the final attainment of all being.

But with respect to ourselves and our five senses, what is the extent of our capacity? We constantly feel in spite of ourselves, and never because we will do so: it is impossible for us to avoid having the sensation which our nature ordains when any object excites it. The sensation is within us, but depends not upon ourselves. We receive it, but how do we receive it? It is evident that there is no connection between the stricken air, the words which I sing, and the impression which these words make upon my brain.

We are astonished at thought, but sensation is equally wonderful. A divine power is as manifest in the sensation of the meanest of insects as in the brain of Newton. In the meantime, if a thousand animals die before our eyes, we are not anxious to know what becomes of their faculty of sensation, although it is as much the work of the Supreme Being as our own. We regard them as the machines of nature, created to perish, and to give place to others.

For what purpose and in what manner may their sensations exist, when they exist no longer? What need has the author of all things to preserve qualities, when the substance is destroyed? It is as reasonable to assert that the power of the plant called “sensitive,” to withdraw its leaves towards its branches, exists when the plant is no more. You will ask, without doubt, in what manner the sensation of animals perishes with them, while the mind of man perishes not? I am too ignorant to solve this question. The eternal author of mind and of sensation alone knows how to give, and how to preserve them.

All antiquity maintains that our understanding contains nothing which has not been received by our senses. Descartes, on the contrary, asserts in his “Romances,” that we have metaphysical ideas before we are acquainted with the nipple of our nurse. A faculty of theology proscribed this dogma, not because it was erroneous, but because it was new. Finally, however, it was adopted, b............