Of all the animals, man is the only one that is cruel. He is the only one that inflicts pain for the pleasure of doing it.
People speak sometimes about the “bestial” cruelty of man, but that is terribly unjust and offensive to beasts, no animal could ever be so cruel as a man, so artfully, so artistically cruel.
He who is cruel to animals becomes hard also in his dealings with men. We can judge the heart of a man by his treatment of animals.