MENO: What was it, and who were they? SOCRATES: Those who tell it are priests and priestesses of the sort who make it their business to be able to account for the functions which they perform. Pindar speaks of it too, and many another of the poets who are divinely inspired. What they say is this-see whether you think they are speaking the truth. They say that the soul of man is immortal. At one time it comes to an end-that which is called death-and at another is born again, but is never finally exterminated. On these grounds a man must live all his days as righteously as possible. […] Thus the soul, since it is immortal and has been born many times, and has seen all things both here and in the other world, has learned everything that is.

(Plato)