One of the rivers flowing in the underworld (Hades). The shadows (the souls of the dead) who drank from the water of this river had forgotten everything about their mortal past that they had lived in the world.

In addition, Eris's daughter is a Naiad fairy (Naiad nemfi). This fairy is likely to be regarded as the symbolized of forgetfulness and separated from the river Lethe.

Lethe expressions and motifs are found in many important literary works. Although different works are different from each other and the description of mythology, the basic feature of forgetfulness does not change much. An example is Dante's Divine Comedy. Dante gave a name to a harp found in Araf. According to Dante, the water is a river that makes you forget their past.