Teiresias was a blind seer (however contradictory that may seem) of Thebes, the son of Everes and the nymph Chariclo. When Zeus and Hera were disputing whether man or woman derives the greater pleasure from the sex act, Teiresias was called in as an impartial arbiter, since as a result of striking a pair of coupling snakes he had earlier been transformed for seven years into a woman.

His verdict was that women experienced a satisfaction nine or ten times greater. This reply angered Hera, who blinded Teiresias, but at the same time gave him the gift of prophecy. His name is thus based on teirea, 'heavenly bodies', 'signs', the Epic Greek plural of teras, 'sign', 'wonder', 'portent', and we can call him 'interpreter of portents', 'sign-reader'.