have so far considered only the physical man; let us try to look at him now in his metaphysical and moral aspects.
I see in all animals only an ingenious machine to which nature has given senses in order to keep itself in motion and protect itself, up to a certain point, against everything that is likely to destroy or disturb it. I see exactly the same things in the human machine, with this difference: that while nature alone activates everything in the operations of a beast, man participates in his own actions in his capacity as a free agent. The beast chooses or rejects by instinct, man by an act of freewill, which means that the beast cannot deviate from the laws which are prescribed to it, even when it might be advantageous for it to do so, whereas a man often deviates from such rules to his own prejudice. That is why a pigeon would die of hunger beside a dish filled with choice meats and a cat beside a pile of fruits or grain, even though either could very well nourish itself with the foods it disdains, if only it were informed by nature to try them. Then we see, too, that dissolute men abandon themselves to the excesses that bring on fevers and death, because the intellect depraves the senses and the will continues to speak when nature is silent.