As Oedipus begins to realize that he might be the one who killed Laius at the fork in the road, Jocasta reassures him that oracles and prophecies are not true. She tells him that although the oracle foretold that her son would murder his father and marry his mother, this could not have happened. She says she beat the oracle by having her infant son put out to die through being exposed on a hillside. This son is dead, she believes.

Jocasta also clings to her belief in the ability of humans to beat the gods because the alternative is so horrible to her. She does not want to accept that it is possible that her son could have killed her husband. Even worse, she does not want to believe that she is married to her son. To have violated the incest taboo would be more than she could bear.

The chorus, which is the voice of conventional morality in the play, disagrees vehemently with Jocasta's point of view. From their perspective, what she is saying is the greatest of sins, one that strikes at the foundations of the social order. If the prophecies given by the gods are not true, the gods lack power and the universe is a place of chaos and disorder.