Philosophical school, probably founded by Pythagoras 0441; 525 BC.
It originated as a religious brotherhood or an association for the moral reformation of society; brothers were sworn to strict loyalty and secrecy. The brotherhood had much in common with the Orphic communities (see Orphism ), which sought by rites and abstinence to purify the believer's soul and enable it to escape from the "wheel of birth." Pythagoreanism held that reality, at its deepest level, is mathematical, that philosophy can be used for spiritual purification, that the soul can rise to union with the divine, and that certain symbols have mystical significance. It was the first important Western system of thought to advocate vegetarianism. The school became extinct in the mid-4th century.