This quotation from Plato’s Republic is used over and over in ancient European literature. I first read it in 1980 as a college student in Philosophy 101. This is my understanding of how it works. All the dead go to the underworld. However, those who are good go to a special place called Elysian Fields, across the River Lethe. Hades has three realms. We are more familiar with Tartarus, rather than Elysian Fields, where you must cross the River Styx, and pass by the gate which is guarded by Cerberus, the three headed dog. Note, in ancient Greek literature, almost anyone could write a story about the Gods and suddenly that was the standard Theology. So, these stories vary and it is hard to pin down what was the standard belief.
Plato adds a new dimension though. For Plato, the good reunite with The Forms. In my opinion, he is making a type of pre-Christian prophesy about Heaven. In any case, the good go to the good place but first they must drink from the River of Forgetfulness, my professor tells me.
As a 19 year old, sitting in class, I thought, “What? I don’t want to forget anything. I want to remember everything”. Now, as an older man, my opinion has changed. After all the things we see within a life time in this world, forgetting the past seems sweeter and sweeter with each passing year. I look forward to when my time comes to “drink from the River of Forgetfulness”.
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.