Oedipus Rex is the story of a nobleman who seeks knowledge that in the end destroys him. His greatness is measured in part by the fact that the gods have prophesied his fate: the gods do not take interest in insignificant men. Before the action of the play begins, Oedipus has set out to discover whether he is truly the son of Polybus and Merope, the king and queen who have brought him up. He learns from the oracle of Apollo at Delphi, the most powerful interpreter of the voice and the will of the gods, that he will kill his father and marry his mother. His response is overwhelmingly human: he has seen his moira, his fate, and he can't accept it. His reaction is to do everything he can, including leaving his homeland as quickly as possible, to avoid the possibility of killing Polybus and marrying Merope.
The Greek audience would have known that Oedipus was a descendant of Kadmos, founder of Thebes, who had sown the dragon teeth that produced the Spartoi (the sown men). Legend determined that the Kingship of Thebes would be in dispute, with fraternal rivalry resembling that of the Spartoi, who fought and killed each other. This bloody legacy follows Oedipus, but it also reaches into all the plays of the trilogy. For example, in Antigone, we learn that Antigone's brothers Polyneices and Eteocles killed each other in the shadow of the city walls. Thus, the fate Oedipus attempts to avoid actually dooms most of the characters in the true plays, including his true father, Laios, and his daughter Antigone.
Sophocles develops the drama in terms of Irony: the disjunction between what seems to be true and what is true. Knowing the outcome of the action, the audience savors the ironic moments from the beginning of the play to the end. Oedipus flees his homeland, to avoid fulfilling the prophecy, only to run headlong into the fate foretold by the Oracle. He unwittingly returns to his original home, Thebes, and to his parents, murdering Laios, his true father, at a crossroads on the way and marrying lokaste, his true mother, and becoming king of Thebes. The blind seer Teiresias warns Oedipus not to pursue the truth, but, in human fashion, Oedipus refuses to heed Teiresias's warnings. When the complete truth becomes clear to Oedipus, he physically blinds Teiresias, Oedipus must now look inward for the truth, without the distractions of surface experiences.
The belief that the moral health of the ruler directly affected the security of the polis was widespread in Athenian Greece. Indeed, the Athenians regarded their state as fragile like a human being whose health, physical and moral, could change suddenly. Because the Greeks were concerned for the well-being of their state, the polis often figures in the tragedies. The Sophoclean Oedipus trilogy is usually called the Theban plays, a terminology that reminds us that the story of Oedipus can be read as the story of an individual or as the story of a state.
Oedipus Rex examines the tension between and interdependence of the individual and the state. The agricultural and ritual basis of the Dionysian festivals, in which Greek drama developed, underscores the importance the Greeks attached to the individual's dependence on the state that feeds him and on the proper ways of doing things. This could be planting and harvesting or worshipping the gods or living as part of a political entity. The underlying conflict in the play is political. The political relationship of human beings to the gods, the arbiters of their fate, is dramatized in Oedipus's relationship with the seer Teiresias. If he had his way, Oedipus might disregard Teiresias entirely. But Oedipus can't command everything, even as ruler. His incomplete knowledge, despite his wisdom, is indicative of the limitations of every individual.
The contrast of Oedipus and Creon, lokaste's brother, is one of political style. Oedipus is a fully developed character who reveals himself as sympathetic but willful. He acts on his misunderstanding of the prophecy without re-consulting the oracle. He marries lokaste and blinds himself without re-consulting the oracle. Creon, who is much less complicated, never acts without consulting the oracle and thoughtfully reflecting on the Oracle's message. Oedipus sometimes behaves tyrannically, and he appears eager for power. Creon takes power only when forced to do so. The depth of Sophocles’ character development was unmatched, except by his contemporary Euripides, for almost two thousand years. Sophocles’ drama is one of psychological development. His audiences saw Oedipus as a model for human greatness, but also as a model for the human capacity to fall from a great height. The play is about the limits of human knowledge; it is also about the limits and the frailty of human happiness.