Платон: The Republic

All the souls had now chosen their lives, and they went in the order of their choice to Lachesis, who sent with them the genius whom they had severally chosen, to be the guardian of their lives and the fulfiller of the choice: this genius led the souls first to Clotho, and drew them within the revolution of the spindle impelled by her hand, thus ratifying the destiny of each; and then, when they were fastened to this, carried them to Atropos, who spun the threads and made them irreversible, whence without turning round they passed beneath the throne of Necessity; and when they had all passed, they marched on in a scorching heat to the plain of Forgetfulness, which was a barren waste destitute of trees and verdure; and then towards evening they encamped by the river of Unmindfulness, whose water no vessel can hold; of this they were all obliged to drink a certain quantity, and those who were not saved by wisdom drank more than was necessary; and each one as he drank forgot all things. Now after they had gone to rest, about the middle of the night there was a thunderstorm and earthquake, and then in an instant they were driven upwards in all manner of ways to their birth, like stars shooting. He himself was hindered from drinking the water. But in what manner or by what means he returned to the body he could not say; only, in the morning, awaking suddenly, he found himself lying on the pyre.

And thus, Glaucon, the tale has been saved and has not perished, and will save us if we are obedient to the word spoken; and we shall pass safely over the river of Forgetfulness and our soul will not be defiled. Wherefore my counsel is, that we hold fast ever to the heavenly way and follow after justice and virtue always, considering that the soul is immortal and able to endure every sort of good and every sort of evil. Thus shall we live dear to one another and to the gods, both while remaining here and when, like conquerors in the games who go round to gather gifts, we receive our reward. And it shall be well with us both in this life and in the pilgrimage of a thousand years which we have been describing.