The Myth of Er (/ɜːr/; ‹See Tfd›Greek: Ἤρ, translit. ér, gen.: Ἠρός) is a legend that concludes Plato's Republic (10.614–10.621). The story includes an account of the cosmos and the afterlife that greatly influenced religious, philosophical, and scientific thought for many centuries.
The story begins as a man named Er, son of Armenios (Ἀρμένιος), of Pamphylia, dies in battle. When the bodies of those who died in the battle are collected, ten days after his death, Er remains undecomposed. Two days later he revives on his funeral-pyre and tells others of his journey in the afterlife, including an account of reincarnation and the celestial spheres of the astral plane. The tale includes the idea that moral people are rewarded and immoral people punished after death.
Although called the Myth of Er, the word "myth" here means "word, speech, account", rather than the modern meaning. The word is used at the end when Socrates explains that because Er did not drink the waters of Lethe, the account (mythos in Greek) was preserved for us.