"But woolen articles are never taken into temples, nor are (the Egyptians) buried with them. That is not lawful. They agree in this with the so-called Orphic and Bacchic practices (which are really Egyptian) and with the Pythagoreans. For it is not lawful for one who partakes in these rites to be buried in woolen clothes. There is a sacred account given on this subject."
(Herodotus Histories II. 81)
"On the subject of reincarnation Xenophanes bears witness in an elegy which begins `Now I will turn to another tale and show the way'. What he says about Pythagoras runs thus: Once they say that he was passing by when a puppy was being whipped, and he took pity and said, `Stop, do not beat it. For it is the soul of a friend that I recognized when I heard it giving tongue.'"
(Diogenes Laertius 8. 36)
"Moreover the Egyptians are the first to have maintained the doctrine that the soul of man is immortal, and that when the body perishes, it enters into another animal that is being born at the time, and when it has been the complete round of the creatures of the dry land and of the sea and of the air it enters again into the body of a man at birth. And its cycle is completed in 3000 years. There are some Greeks who have adopted this doctrine, some in former times, and some in later ones, as if it were their own invention. Their names I know, but refrain from writing down."
(Herodotus II. 123)
"None the less, the following became universally known: first, that he maintains that the soul is immortal; second, that it changes into other kinds of living things; third, that events recur in certain cycles and that nothing is ever absolutely new; and fourth, that all living things sould be regarded as akin. Pythagoras seems to have been the first to bring these beliefs into Greece."
(Porphyrius, Life of Pythagoras 19)
"Above all else (Pythagoras) forbade the eating of red mullet and black-tail. And he required abstinence from the heart and from beans. Also (according to Aristotle), on certain occasions, from the womb and from mullet.... He sacrificed only inanimate things. But others say that he used only cocks and suckling kids and piglets, and never lambs."
(Diogenes Laertius 8. 19)
"So Pythagoras turned geometrical philosophy into a form of liberal education by seeking its first principles in a higher realm of reality...."
(Proclus In Eucl. p. 65 Friedlander)
"The Pythagoreans, according to Aristoxenus, practiced the purification (catharsis) of the body by medicine, and of the soul by music."
(Cramer, Paris Anthology I. 172)
"Ten is the very nature of number. All Greeks and all barbarians alike count up to ten, and having reached ten revert again to the unity. And again, Pythagoras maintains, the power of the number 10 lies in the number 4, the tetrad. This is the reason: if one starts at the unit (1) and adds the successive number up to 4, one will make up the number 10 (1+2+3+4 = 10). And if one exceeds the tetrad, one will exceed 10 too.... So that the number by the unit resides in the number 10, but potentially in the number 4. And so the Pythagoreans used to invoke the Tetrad as their most binding oath: `By him that gave to our generation the Tetractys, which contains the fount and root of eternal nature...'"
(Aetius I. 3.8)