It requires twenty years for a man to rise from the vegetable state in which he is within his mother's womb, and from the pure animal state which is the lot of his early childhood, to the state when the maturity of reason begins to appear. It has required thirty centuries to learn a little about his structure. It would need eternity to learn something about his soul. It takes an instant to kill him.
People must have renounced, it seems to me, all natural intelligence to dare to advance that animals are but animated machines.... It appears to me, besides, that such people can never have observed with attention the character of animals, not to have distinguished among them the different voices of need, of suffering, of joy, of pain, of love, of anger, and of all their affections. It would be very strange that they should express so well what they could not feel.