The following passage is found in the “Système de la Nature,” London edition, page 84: “We ought to define life, before we reason concerning soul; but I hold it to be impossible to do so.”

On the contrary, I think a definition of life quite possible. Life is organization with the faculty of sensation. Thus all animals are said to live. Life is attributed to plants, only by a species of metaphor or catachresis. They are organized and vegetate; but being incapable of sensation, do not properly possess life.

We may, however, live without actual sensation; for we feel nothing in a complete apoplexy, in a lethargy, or in a sound sleep without dreams; but yet possess the capacity of sensation. Many persons, it is too well known, have been buried alive, like Roman vestals, and it is what happens after every battle, especially in cold countries. A soldier lies without motion, and breathless, who, if he were duly assisted, might recover; but to settle the matter speedily, they bury him.

What is this capacity of sensation? Formerly, life and soul meant the same thing, and the one was no better understood than the other; at bottom, is it more understood at present?

In the sacred books of the Jews, soul is always used for life.

“Dixit etiam Deus, producant aqu? reptile anim? viventis.” (And God said, let the waters bring forth abundantly the moving creature which hath a living soul.)

“Creavit Deus cete grandia, et omnem animam viventem, atque motabilem quam produxerant aqu?.” (And God created great dragons (tannitiim), and every living soul that moveth, which the waters brought forth.) It is difficult to explain the creation of these watery dragons, but such is the text, and it is for us to submit to it.

“Producat terra animam viventem in genere suo, jumenta et reptilia.” (Let the earth produce the living soul after its kind, cattle and creeping things.)

“Et in quibus est anima vivens, ad vescendum.” (And to everything wherein there is a living soul [every green herb], for meat.)

“Et inspiravit in faciem ejus spiraculum vit?, et factus est homo in animam viventem.” (And breathed into his nostrils the breath of life, and man became a living soul.)............