Our editors will review what you’ve submitted and determine whether to revise the article. Join Britannica's Publishing Partner Program and our community of experts to gain a global audience for your work! In Orphism, a Greek mystical religious movement, it was believed that the newly dead who drank from the River Lethe would lose all memory of their past existence. The initiated were taught to seek instead the river of memory, Mnemosyne, thus securing the end of the transmigration of the soul. At the oracle of Trophonius near Lebadeia (modern Levadhia, Greece), which was thought to be an entrance to the underworld, there were two springs called Lethe and Mnemosyne. Aristophanes’ The Frogs mentions a plain of Lethe. In Book X of Plato’s The Republic the souls of the dead must drink from the “river of Unmindfulness” before rebirth. In the works of the Latin poets Lethe is one of the five rivers of the underworld. Learn More in these related Britannica articles:Greek religion: Eschatology…drank from the stream of Lethe, the river of oblivion, and forgot all of their previous experiences. (See alsoOrpheus; mystery religion: History). …Orphic religion, a Hellenistic mystery religion, thought to have been based on the teachings and songs of the legendary Greek musician Orpheus. No coherent description of such a religion can be constructed from historical evidence. Most scholars agree that by the 5th century bcthere was at least an Orphic…Mnemosyne, in Greek mythology, the goddess of memory. A Titaness, she was the daughter of Uranus (Heaven) and Gaea (Earth), and, according to Hesiod, the mother (by Zeus) of the nine Muses. She gave birth to the Muses after Zeus went to Pieria and stayed with her nine consecutive nights.…