In Classical Greek, Lethe (LEE-thee) literally means "forgetfulness" or "concealment". The Greek word for "truth" is a-lethe-ia, meaning "un-forgetfulness" or "un-concealment".
In Greek mythology, Lethe is one of the several rivers of Hades. Drinking from the river Lethe ("forgetfulness" or "oblivion") caused complete forgetfulness. Some ancient Greeks believed that souls were made to drink from the river before being reincarnated, so they would not remember their past lives.
Lethe was also a naiad, the daughter of Eris ('Strife' in Hesiod's Theogony). The naiad Lethe is probably a separate personification of forgetfulness rather than a reference to the river which bears her name.
Some private mystery religions taught the existence of another river, the Mnemosyne; those who drank from the Mnemosyne would remember everything and attain omniscience. Initiates were taught that they would receive a choice of rivers to drink from after death, and to drink from Mnemosyne instead of Lethe. These two rivers are attested in several verse inscriptions on gold plates dating to the 4th century BC and onward, found at Thurii in Southern Italy and elsewhere throughout the Greek world.
References to Lethe in later culture
The Myth of Er at the end of Plato's Republic, tells of the dead arriving at the "plain of Lethe", which the river Ameles ("careless") runs through.
There were rivers of Lethe and Mnemosyne at the shrine of Trophonius in Boeotia, from which worshippers would drink before making oracular consultations with the god.
Dav alongside the two beautiful guardians of Oblivion and Memory
Amongst authors in Antiquity, the tiny Limia River near Xinzo de Limia in the province of Ourense in Galicia was said to have the same properties of memory loss as the the legendary Lethe River. In 138 BC, the Roman general Decimus Junius Brutus sought to dispose of the myth, as it impeded his military campaigns in the area. He was said to have crossed the Limia and then called his soldiers on the other side, one by one, by name. The soldiers, astonished that their general remembered their names, crossed the river as well without fear. This act proved that the Limia was not as dangerous as the local myths described.
In The Divine Comedy, the stream of Lethe flows to the centre of the earth from its surface, but its headwaters are located in the Earthly Paradise found at the top of the mountain of Purgatory.
In Sarah Ruhl's play Eurydice, all the shades must drink from Lethe and become like stones, speaking in their inaudible language and forgetting everything of the world. This river is a central theme of the play.
The river of Lethe is also mentioned in Allen Ginsberg's poem "A Supermarket in California".
A river Lethe runs along the southern border of the Skull Kingdom in Terry Brooks' fantasy novel The Sword of Shannara. However, the waters of this river Lethe do not induce forgetfulness; they are merely poisonous to mortal beings.
Swedish melodic death metal band Dark Tranquillity wrote a song entitled "Lethe" on their second album, The Gallery. The song is about dealing with loss or suffering through the use of alcohol. It is based on the Greek myth of the river, likening the river's effects to that of alcohol, and is one of Dark Tranquillity's most popular and well-known songs.
In Dan Simmons' book Hyperion, Sol Weintraub's tale is titled "The Taste of the River Lethe is Bitter." Sol's daughter has contracted a mysterious malady referred to as Merlin's Sickness which causes her to age backwards to conception and forget her life when she sleeps.
Mount Lethe is a fictional volcano in the MMORPG Asheron's Call. It serves an important function in many in-game quests.
Lethe is also the name of a pair of swords wielded by Cervantes de Leon in the video game Soul Calibur II. Perhaps fittingly, its description states that "those who grip these weapons find their heart rendered blank, unable to even remember who they are."
In Samuel Beckett's radio play Embers, the main character Henry describes conversing with his dead wife: "that's what hell will be like, small chat to the babbling of Lethe about the good old days when we wished we were dead".
In Mike Carey's The Sandman Presents: Lucifer miniseries, Lucifer gives water from the River Lethe to the Lilim Briadach to ease his pain.
In Steven Baxter's Xeelee series, he uses the word often as a profanity.
In Sierra Entertainment's Quest for Glory V: Dragon Fire, the Hero must travel to Hades and obtain water from the River Lethe.
San Francisco-based playwright Octavio Solis' play, LETHE, is the story of seniors facing the loss of memory and the caretakers who tend to them. It premiered in August 2006 at the Cornerstone Theater Company Institute.
In the film, "The Matrix," Neo is offered two capsules, one red, one blue. If he chooses the 'red', he forgets everything. If he chooses the 'blue', he becomes aware of his real existence.
In the Buffy the Vampire Slayer Season 6 episodes All The Way, Once More, With Feeling and Tabula Rasa, it is discovered that Willow has cast amnesia spells on Tara, Buffy, and, accidentally, the whole group, by burning a plant called Lethe's bramble.
In Gene Roddenberry's Andromeda, Season 1 episode "The Banks of the Lethe", Captain Hunt has the opportunity to resolve his relationship with his fiancee and say goodbye to the past.
In Robert Heinlein's "Time Enough For Love" there is a reference to "Neolethe" (see the chapter entitled Counterpoint I), which is apparently a powerful sedative.