The prophet Tiresias is an extremely important character in Oedipus Rex. First, he is crucial in revealing essential information used to further the plot. More importantly, though, he is important to the religious theme of the play and to our understanding of the ending of Oedipus Rex and to Oedipus’ life after the play.
The Greeks believed that the gods revealed their will to humans by means of signs. Many natural phenomena, such as the flights of birds and the shapes of livers of sacrifices, signified divine intentions. Specialized prophets like Tiresias interpreted these signs so that people could better understand and follow divine will. Thus Tiresias, one of the more important prophets of the epic tradition, understands the religious implications of the plague.
Finally, Tiresias, as a blind prophet, sees more clearly the true nature of events than the sighted. It is only when Oedipus blinds himself that he too “sees” correctly, with true moral and religious vision. Thus Tiresias is the future of Oedipus.