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.