Pythagorean Fragments and Doctrines

Pythagoras of Samos, who founded a religious and philosophical community at Croton in southern Italy around 530 BC, left no writings of his own, and everything attributed to him survives only through later, often conflicting doxography, much of it embellished or invented by his later followers over the following centuries. The doctrines consistently associated with his school hold that numerical ratios underlie musical harmony (discovered, tradition claims, through experiments with a monochord) and the structure of the cosmos itself, and that the soul is immortal, divine, and reincarnated across many bodies, both human and animal, a belief that led Pythagoreans to practice vegetarianism and ritual purification. The community's secrecy and the legendary status of its founder make separating Pythagoras's own ideas from later accretion an unresolved scholarly problem.