in the rebirth mechanism. Further, Jainism considers asceticism as an important means to spiritual liberation that ends all reincarnation, while Buddhism does not. Classical antiquity Early Greek discussion of the concept dates to the sixth century BCE. An early Greek thinker known to have considered rebirth is Pherecydes of Syros (fl. 540 BCE). His younger contemporary Pythagoras (c. 570–c. 495 BCE), its first famous exponent, instituted societies for its diffusion. Some authorities believe that Pythagoras was Pherecydes' pupil, others that Pythagoras took up the idea of reincarnation from the doctrine of Orphism, a Thracian religion, or brought the teaching from India. Plato (428/427–348/347 BCE) presented accounts of reincarnation in his works, particularly the Myth of Er, where Plato makes Socrates tell how Er, the son of Armenius, miraculously returned to life on the twelfth day after death and recounted the secrets of the other world. There are myths and theories to the same effect in other dialogues, in the Chariot allegory of the Phaedrus, in the Meno, Timaeus and Laws. The soul, once separated from the body, spends an indeterminate amount of time in the intelligible realm (see The Allegory of the Cave in The Republic) and then assumes another body. In the Timaeus, Plato believes that the soul moves from body to body without any distinct reward-or-punishment phase between lives, because the reincarnation is itself a punishment or reward for how a person has lived. In Phaedo, Plato has his teacher Socrates, prior to his death, state: "I am confident that there truly is such a thing as living again, and that the living spring from the dead." However, Xenophon does not mention Socrates as believing in reincarnation, and Plato may have systematized Socrates' thought with concepts he took directly from Pythagoreanism or Orphism. Recent scholars have come to see that Plato has multiple reasons for the belief in reincarnation. One argument concerns the theory of reincarnation's usefulness for explaining why non-human animals exist: they are former humans, being punished for their vices; Plato gives this argument at the end of the Timaeus. Mystery cults The Orphic religion, which taught reincarnation, about the sixth century BCE, produced a copious literature. Orpheus, its legendary founder, is said to have taught that the immortal soul aspires to freedom while the body holds it prisoner. The wheel of birth revolves, the soul alternates between freedom and captivity round the wide circle of