Pythagoras (born about 580 B.C.E.) was a Greek philosopher best known today for his mathematical theorems. He was better known in his own time for his philosophy of the mind and soul which put an emphasis upon purity and catharsis. While few of his or his followers writings are extant, it was believed that he promoted health through a special vegetarian diet.
Antonio Cocchi legitimized his theories about vegetarianism by citing Pythagoras.