In Greek mythology, Lethe (Ancient Greek: Λήθη, 'Forgetfulness', 'Oblivion')^[1] is the personification of forgetfulness and oblivion. According to Hesiod's Theogony, Lethe was the daughter of Eris (Strife), with no father mentioned. Her name was also given to Lethe, the river of oblivion in the Underworld.^[2]

Like all of the children of Eris, as given by Hesiod, Lethe is a personified abstraction allegorizing the meaning of her name, and represents one of the many harmful things which might be thought to result from discord and strife, with no other identity.^[3] The Roman mythographer Hyginus has the equivalent personification of the meaning of the Latin word oblivio (oblivion, forgetfulness)^[4] as the offspring of Ether [Aether] and Earth [Terra].^[5]

The meaning of the Greek lethe may have been influenced by the Greek word aletheia, meaning truth.^[6]

A fragment from one of the plays of Sophocles describes Lethe as "dumb, speechless", and "deprived of all things".^[7] Lethe became associated with the personifications Death (Thanatos) and Sleep (Hypnos).^[8] For example, the Orphic Hymn to Sleep, has Sleep being a "true brother" to Death and Oblivion [Lethe],^[9] while the Roman poet Statius, has the Latin equivalent Oblivio [Forgetfullness] as one of the guards at the entrance to the halls of Sleep.^[10]

In Hellenistic literature, Lethe became a counterpart of Mneme [Μνήμη] the personification of memory, who was more or less identical to the Titan Mnemosyne.^[11] For example, The Greek Anthology (10.67) has:

Memory [Μνήμη] and Oblivion, [Λήθη] all hail! Memory I say in the case of good things, and Oblivion in the case of evil.^[12]

Mnemosyne played an important role in Orphic eschatology, where it was her "work" to remind the soul of the initiate what must be done in the Underworld.^[13] In the Orphic Hymn to Mnemosyne, the goddess is invoked to combat oblivion (lethe). Mnemosyne is contrasted with "evil oblivion (lethe) that harms the mind", and called upon to "stir" in the minds of the initiates "the memory of the sacred rite", and to "ward off oblivion from them".^[14] Lethe and Mnemosyne were also paired at the oracle of Trophonios at Livadeia. The geographer Pausanias, tells us that, before consulting the oracle, one had to drink from the fountain of Lethe to clear one's mind, and afterwards drink from the fountain of Mnemosyne to remember what the oracle says.^[15]

Lethe, as a daughter of Eris, had a negative connotation, which can be seen from the her association with Death, and as the "evil" counterpart of Mneme/Mnemosyne. However Lethe's association with Sleep might perhaps also imply a positive aspect, similar to that of Sleep who is said to "free us of cares" and "offer sweet respite from toil".^[16]

One of the sepulchral epigrams from the seventh book of the The Greek Anthology, apparently an inscription from the "tomb of Teos", mentions a "Lethe". The epigram has Teos as dwelling in the "House of Lethe" in the Underworld, possibly a reference to the daughter of Eris, and her residence there.^[17]

• Athanassakis, Apostolos N., and Benjamin M. Wolkow, The Orphic Hymns, Johns Hopkins University Press, 2013. ISBN 978-1-4214-0882-8. Internet Archive.

• Caldwell, Richard, Hesiod's Theogony, Focus Publishing/R. Pullins Company (June 1, 1987). ISBN 978-0-941051-00-2. Internet Archive.

• The Cambridge Greek Lexicon, edited by J. Diggle et al, Cambridge University Press, 2021 ISBN 978-0-521-82680-8.

• Gantz, Timothy, Early Greek Myth: A Guide to Literary and Artistic Sources, Johns Hopkins University Press, 1996, Two volumes: ISBN 978-0-8018-5360-9 (Vol. 1), ISBN 978-0-8018-5362-3 (Vol. 2).

• The Greek Anthology, Volume II: Book 7: Sepulchral Epigrams. Book 8: The Epigrams of St. Gregory the Theologian, translated by W. R. Paton, Loeb Classical Library No. 68, Cambridge, Massachusetts, Harvard University Press, 1917. ISBN 978-0-674-99075-3. Online version at Harvard University Press.

• The Greek Anthology, Volume IV: Book 10: The Hortatory and Admonitory Epigrams. Book 11: The Convivial and Satirical Epigrams. Book 12: Strato's Musa Puerilis, translated by W. R. Paton, Loeb Classical Library No. 85, Cambridge, Massachusetts, Harvard University Press, 1918. ISBN 978-0-674-99094-4. Online version at Harvard University Press.

• Grimal, Pierre, The Dictionary of Classical Mythology, Wiley-Blackwell, 1996. ISBN 978-0-631-20102-1. Internet Archive.

• Hard, Robin, The Routledge Handbook of Greek Mythology: Based on H.J. Rose's "Handbook of Greek Mythology", Psychology Press, 2004, ISBN 9780415186360. Google Books.

• Hyginus, Gaius Julius, Fabulae in Apollodorus' Library and Hyginus' Fabulae: Two Handbooks of Greek Mythology, Translated, with Introductions by R. Scott Smith and Stephen M. Trzaskoma, Hackett Publishing Company, 2007. ISBN 978-0-87220-821-6.

• Hyginus, Gaius Julius, Fabulae. Latin text at packhum.org.

• Most, G.W., Hesiod, Theogony, Works and Days, Testimonia, Edited and translated by Glenn W. Most, Loeb Classical Library No. 57, Cambridge, Massachusetts, Harvard University Press, 2018. ISBN 978-0-674-99720-2. Online version at Harvard University Press.

• Liddell, Henry George, Robert Scott, A Greek-English Lexicon, revised and augmented throughout by Sir Henry Stuart Jones with the assistance of Roderick McKenzie, Clarendon Press Oxford, 1940. Online version at the Perseus Digital Library.

• Pausanias, Description of Greece with an English Translation by W.H.S. Jones, Litt.D., and H.A. Ormerod, M.A., in 4 Volumes. Cambridge, Massachusetts, Harvard University Press; London, William Heinemann Ltd. 1918. Online version at the Perseus Digital Library.

• Plato, Republic, Volume II: Books 6-10, edited and translated by Christopher Emlyn-Jones, William Preddy, Loeb Classical Library No. 276, Cambridge, Massachusetts, Harvard University Press, 2013. ISBN 978-0-674-99651-9. Online version at Harvard University Press.

• The Pocket Oxford Latin Dictionary, edited by James Morwood, Oxford University Press, 1994. ISBN 0-19-864227-X.

• Smith, William, Dictionary of Greek and Roman Biography and Mythology, London (1873). Online version at the Perseus Digital Library.

• Sophocles, Fragments, edited and translated by Hugh Lloyd-Jones, Loeb Classical Library No. 483. Cambridge, Massachusetts, Harvard University Press, 1996. ISBN 978-0-674-99532-1. Online version at Harvard University Press.

• Statius, Statius with an English Translation by J. H. Mozley, Volume II, Thebaid, Books V–XII, Achilleid, Loeb Classical Library No. 207, London: William Heinemann, Ltd., New York: G. P. Putnamm's Sons, 1928. ISBN 978-0674992283. Internet Archive.

• Stesichorus, Ibycus, Simonides, Greek Lyric, Volume III: Stesichorus, Ibycus, Simonides, and Others, edited and translated by David A. Campbell, Loeb Classical Library No. 476, Cambridge, Massachusetts, Harvard University Press, 1991. ISBN 978-0-674-99525-3. Online version at Harvard University Press.

• Walde, s.v. Mneme, in Brill’s New Pauly Online, Antiquity volumes edited by: Hubert Cancik and, Helmuth Schneider, English Edition by: Christine F. Salazar, Classical Tradition volumes edited by: Manfred Landfester, English Edition by: Francis G. Gentry, published online: 2006.

• West, M. L. (1966), Hesiod: Theogony, Oxford University Press. ISBN 0-19-814169-6.