“What is man? and what difference is there between him and other plants, between him and all the other animals of the world? None, obviously. Fortuitously placed, like them, upon this globe, he is born like them; like them, he reproduces, rises, and falls; like them he arrives at old age and sinks like them into nothingness at the close of the life span Nature assigns each species of animal, in accordance with its organic construction. Since the parallels are so exact that the inquiring eye of philosophy is absolutely unable to perceive any grounds for discrimination, there is then just as much evil in killing animals as men, or just as little, and whatever be the distinctions we make, they will be found to stem from our pride's prejudices, than which, unhappily, nothing is more absurd.

If all individuals were possessed of eternal life, would it not become impossible for Nature to create any new ones? If Nature denies eternity to beings, it follows that their destruction is one of her laws. Now, once we observe that destruction is so useful to her that she absolutely cannot dispense with it, and that she cannot achieve her creations without drawing from the store of destruction which death prepares for her, from this moment onward the idea of annihilation which we attach to death ceases to be real; there is no more veritable annihilation; what we call the end of the living animal is no longer a true finis, but a simple transformation, a transmutation of matter, what every modern philosopher acknowledges as one of Nature's fundamental laws. According to these irrefutable principles, death is hence no more than a change of form, an imperceptible passage from one existence into another, and that is what Pythagoras called metempsychosis”