There are two things which speak against flesh-eating: one thing is that meat, as a substance, hinders spiritual progress, and the other is that the unkindness toward the animals is a breach of moral law. Speaking about the first question, it is no doubt true that meat causes two kinds of harm to an adept. One is that it produces in man to a certain extent the animal nature; also it has an influence on the character of man. The nature of the animal he eats certainly has an influence upon a man's character. It was therefore that the prophets of Beni Israel forbade their followers to eat the flesh of certain kinds of animals and birds.