"The theory of metempsychosis plays almost as great a part in Greek as in Indian religious thought. Both Pythagoras and Empedocles claimed to possess the power of recollecting their past births. Metempsychosis is refered to in many places in Pindar, and, with the complementary doctrine of Karma, it is the key-stone of the philosophy of Plato. The soul is for ever travelling in a “cycle of necessity”. The evil it does in one semicircle of its pilgrimage is expiated in the other. “Each soul”, we are told in the Phaedrus, “returning to the election of a second life, shall receive one agreeable to his desire”. But most striking of all is the famous apologue of Er the Pamphylian, with which Plato appropriately ends the Republic […] “In like manner, some of the animals passed into men, and into one another, the unjust passing into the wild, and the just into the tame.”’"