The Chorus wonders aloud about the origins of Oedipus. An old man is led in by Oedipus’ servants and identified as the herdsman, the man who gave the baby to the Corinthian messenger so many years ago: Oedipus insists on him revealing exactly what he knows. The messenger says that Oedipus is that same baby, who was abandoned by his father and mother - and the herdsman reacts with fear and begs the messenger to hold his tongue. Oedipus threatens the messenger with physical violence, and finally the man confesses that the baby was a child of Laius's house.
Oedipus asks if it was a slave's child or Laius's child, and the shepherd confesses that it was Laius's child - a child that Jocasta gave him to expose on the hillside because of a prophecy that he would kill his father. The shepherd says he didn't have the heart to kill the infant, so he took it to another country instead. “They will all come, / all come out clearly!” cries Oedipus. “Light of the sun, let me / look on you no more!” (1183-4). He has finally realized what has happened and all exit except the Chorus. The Chorus reflects on the mutable nature of human happiness - all happiness, they say, is only “a seeming” and “after that turning away” (1191-2). Nobody can ultimately escape fate.
A messenger enters from the palace with horrifying news. In a long speech, he says that Jocasta went into the palace, went straight to her bedroom and slammed the door, tearing her hair with her fingers. There she cried out to Laius and bemoaned the tragedy of her son/husband. Oedipus, bursting into the palace and demanding a sword, found that Jocasta had hanged herself. Moaning horribly, he cut her down and laid her on the ground. Then he took the gold brooches with which she had fastened her gown, and, thrusting his arms out at full length, gouged his eyes out. Again and again he pierced he eyes until bloody tears streamed down his cheeks. Now he shouts for someone to open the palace doors (presumably the doors of the skene building) and show all of Thebes the man who killed Laius. He swears he will flee this country to rid his house of his curse.
The doors to the palace are thrown open, and Oedipus stumbles out. The Chorus cries out in agony at the sight and hides its own eyes: “this is”, they say, “a terrible sight for men to see” (1298). Oedipus cries out to the city in a voice that hardly seems his own. The Chorus wails that Oedipus is untouchable and too terrible for eyes to see - that he has been punished in both body and soul. Oedipus calls for someone to be his guide. He pleads with the Chorus to lead him out of Thebes and curses the shepherd who saved his life when he was a baby. The Chorus tells him that surely death would have been better than blindness, and Oedipus replies by asking how he could have possibly met his parents in the underworld with seeing eyes. How could he have looked upon children whom he had begotten in sin? He begs the Chorus to hide him away from human sight.
Creon enters, and asks the Chorus to take Oedipus inside: “only kin”, he thinks, “should see and hear the troubles / of kin” (1430-1). Oedipus begs to be cast out of Thebes. Creon replies that he must wait for instructions from Apollo. Oedipus argues that Apollo's instructions were clear: the unclean man must leave Thebes. Oedipus also asks Creon to bury Jocasta properly and to take care of his daughters. But before he goes, he begs to see his daughters once more. These girls, Antigone and Ismene are led in, and Oedipus caresses them with hands that are both father's and brother's. He weeps for the fact that they will never be able to find husbands with this tragic family lineage. With Creon's promise that he will send him away from Thebes to fulfill Apollo's word, Oedipus releases his children and he and Creon enter the palace again.
Alone on the stage, the Chorus asks the audience to remember the story of Oedipus, the greatest of men. He alone could solve difficult riddles and was envied my his fellows for his prosperity - but now the greatest of misfortunes has befallen him. The Chorus warns the audience that mortal men must always “look upon that last day always” (1529). Only after life can one be sure that one’s life is “secure from pain” (1530).
Sophocles’ use of dramatic irony takes center stage in the play's third act. Here, the narrative revolves around two different attempts to change the course of fate: Jocasta and Laius's killing of Oedipus at birth and Oedipus's flight from Corinth as an adult. In both cases, an oracle's prophecy comes true regardless of the characters' actions. Jocasta kills her son only to find him restored to life and married to her. Oedipus leaves Corinth only to find that in so doing he has found his real parents and carried out the oracle's words. Both Oedipus and Jocasta prematurely exult over the failure of oracles, only to find that the oracles ultimately proved accurate. Furthermore, each time a character tries to avert a future predicted by the oracles, the audience knows their attempt is futile. As this final Chorus confirms: fate is inescapable.
Even the manner in which Oedipus and Jocasta express their disbelief in oracles proves ironic. In an attempt to comfort Oedipus, Jocasta tells him that oracles are powerless, yet minutes later we see her praying to the same gods whose powers she just mocked (911). Oedipus rejoices over Polybus's death as a sign that oracles are fallible, yet he will not return to Corinth for fear that the oracle's statements concerning Merope could still come true (976). Regardless of what they say, both Jocasta and Oedipus continue to suspect that the oracles could be right, that gods can predict and affect the future. In a way, then, they reflect both the Athenian audience's own ambivalence towards oracles.
Yet, if Oedipus discounts the power of oracles, he values the power of truth. Instead of relying on the gods, Oedipus counts on his own ability to root out the truth - indeed, the opening of the play posits him as a miraculous riddle-solver. The contrast between trust in the gods' oracles and trust in intelligence plays out in this story much like the contrast between religion and science in nineteenth-century novels. But the irony here, of course, is that the oracles and Oedipus's scientific method both lead to the same outcome. Oedipus's search for truth fulfills the oracles' prophesies. Ironically, it is Oedipus's rejection of the oracles that uncovers their power; he relentlessly pursues truth instead of trusting in the gods. As Jocasta says, if he could just have left well enough alone, he would never have discovered his own awful secret.
In his search for the truth, Oedipus shows himself to be a formidable detective, ruthless in his pursuit of solving the mystery. This persistence is the same characteristic that brought him to Thebes; he was the only man capable of solving the Sphinx's riddle. His intelligence is what makes him great, and yet also proves his tragic flaw. Indeed, his problem-solver's mind leads him closer and closer to tragedy as he works through the mystery of his birth. In the Oedipus myth, marriage to Jocasta was the prize for ridding Thebes of the Sphinx. Thus Oedipus's intelligence, a trait that brings Oedipus closer to the gods, is what also causes him to commit the most heinous of all possible sins. In killing the Sphinx, Oedipus is the city's savior, but in killing Laius (and marrying Jocasta), he is its scourge, the cause of the blight that has struck the city at the play's opening. Thus Oedipus Rex has been interpreted both as a warning against knowing more than one needs to know, and as a heroic testament to scientific investigation and truth-seeking. The play bears out both readings.
The Sphinx's riddle echoes throughout the play, even though Sophocles never quotes her actual question. Audiences familiar with the myth would have known the Sphinx's words: "What is it that goes on four feet in the morning, two feet at midday, and three feet in the evening?" Oedipus's answer, of course, was "a man." And in the course of the play, Oedipus himself proves to be that same man, an embodiment of the Sphinx's riddle. There is much talk of Oedipus's birth and his exposure as an infant - here is the baby of which the Sphinx speaks, forced, in this instance, to crawl on four feet as his ankles are pierced. Oedipus throughout most of the play is the adult man, standing on his own two feet instead of relying on others, even gods. And at the end of the play, Oedipus will leave Thebes an old blind man, using a cane. In fact, Oedipus's name means "swollen foot", presumably because of the pins thrust through his ankles as a baby. Oedipus is more than merely the solver of the Sphinx's riddle - he embodies its solution.
Perhaps the most significant example of dramatic irony in this play, however, involves the frequent reference to eyes, sight, light, and perception throughout. Oedipus, of course, cannot see behind him or in front of him. Unlike blind Teiresias, the seer, he is firmly located in the present. Accordingly, then, Teiresias, as he says early in the play, sees Oedipus as blind. The irony is that sight here means two different things. Oedipus is blessed with the gift of perception; he was the only man who could "see" the answer to the Sphinx's riddle. Yet he cannot see what is right before his eyes, blind to the truth, for all he seeks it. Teiresias's presence in the play, then, is doubly important. As a blind old man, he foreshadows Oedipus's own future, and the more Oedipus mocks his blindness, the more ironic he sounds to the audience. Teiresias is a man who understands the truth without the use of his sight; Oedipus is the opposite, a sighted man who is blind to the truth right before him. Soon Oedipus will switch roles with Teiresias, becoming a man who sees the truth and loses his sense of sight.
Teiresias is not the only character who uses sight as a metaphor. When Creon appears after learning of Oedipus's accusation of him, he asks “Were his eyes straight in his head?” (528). Yet Oedipus will be ashamed to look any who love him in the eyes. Indeed, one reason that he blinds himself is because he does not want to have to look on his father or mother in the afterlife. A number of binaries are associated with the idea of sight and blindness: illusion and disillusion, light and dark, morning and night. Time casts its searchlight at random, and when it does, it uncovers terrible things. The happiness of the "morning of light" is an illusion, while the reality is the "night of endless darkness." The Chorus, meanwhile, wishes it had never seen Oedipus. Not only has he polluted his own sight and his own body by marrying his mother and killing his father, he is a pollutant of others' sights by his very existence. When Oedipus enters, blinded, the Chorus tells him he has sprung to a terrible place “whereof men’s ears / may not hear, nor their eyes behold it” (1313-4). Oedipus has become the very blight he wishes to remove from Thebes, a monster more terrible than the Sphinx that must be cast out in order to save the kingdom.