The close analogy between Pythagoreanism and Orphism has been recognized from Herodotus (ii.
Both inculcated a peculiar kind of ascetic life; both had a mystical speculative theory of religion, with purificatory rites, abstinence from beans, &c.; but Orphism was more especially religious, while Pythagoreanism, at least originally, inclined more to be a political and philosophical creed.
According to the relative predominance of these two elements arose Gnosticism, the Patristic theology, and the philosophical schools of Neo-Pythagoreanism, Neo-Platonism and eclectic Platonism.
(2) The first purely philosophical phenomenon of the Alexandrian school was Neo-Pythagoreanism, the second and last Neo-Platonism.
What is more, both Speusippus and Xenocrates founded their own philosophies on this very Pythagoreanism of Plato.