Playing an integral part in the play, the Chorus of Oedipus Rex, the men of Thebes, are orginally supportive, then critical, and finally, sympathethic to Oedipus. In the line cited above, the Chorus makes the critical observation that no one can escape fate, for in time Fate will find him because free will has its limitations of time and character. Thus, this line is central to the themes of Oedipus Rex.
- Fate is innate
While it is his pride and intelligence that assists Oedipus in solving the riddle of the sphinx, ironically, this pride and quick temper, his fatal flaws, are also agents of his undoing as his refusal to learn of his past allows his destruction since there is enough time for all those with this knowledge to appear and reveal the truth. Despite the warnings of Teiresias that he
...will never tell you what I know.
Now it is my misery, then, it would be yours. (316-317)
Oedipus persists until with time, his past is revealed by messengers and the shepherd.
Certainly, as the second messenger says in the EXODOS,
The greatest griefs are those we cause ourselves.(1262)
- Human free will has its limits
Despite the efforts of the parents of Oedpius, Jocasta and Laius, to prevent their son from fulfilling the prophecy about him, by their binding and leaving him out for a certain death, Oedipus is rescued by a shepherd. Later, Oedipus inadvertently encounters his real father and kills him without realizing the magnitude of what he has done. So, while he has been free to kill, Oedipus unconsciously seals his fate as he is made king of Thebes and marries his mother after Laius's death and his solving of the riddle of the sphinx that curses Thebes.
Further, despite the efforts of Oedipus to learn the truth so that he can quell the plague that torments the citizens of Thebes, he cannot change his fate that he is cursed and the cause of the plague himself. When the shepherd tells Oedipus why he rescued him as a baby,
I pitied the baby, my king,
And I thought that this man would take him far away
To his own country.
He saved him--but for what a fate!
For, if you are what this man says you are,
No man living is more wretched than Oedipus. (1113-1117)
Oedipus realizes that he has been victimized by fate and his choices have been limited since his fate has loomed over him from his birth. Above all, his ignorance of his past has prevented him from helping his subjects and even himself.
The quote that is listed in the question indicates the way that Oedipus is a victim of fate and tragically is forced to identify himself as the murderer that he searches for so desperately throughout the entire play. Oedipus faces a massive conflict in this tragedy where he declares, very close to the beginning of the play, that as the King of Thebes and as its saviour, he will track down the murderer of the former king and bring him to justice in order to stop the plague that is killing so many of his citizens:
And on the murderer this curse I lay
(On him and all the partners in his guilt):--
Wretch, may he pine in utter wretchedness!
And for myself, if with my privity
He gain admittance to my hearth, I pray
The curse I laid on others fall on me.
See that ye give effect to all my hest,
For my sake and the god's and for our land,
A desert blasted by the wrath of heaven.
The dramatic irony of this curse so close to the beginning of the play is obvious, as he is cursing himself. The rest of the play discloses how he gradually discovers that he is the criminal he so desperately seeks and wants to punish. The quote therefore refers to the way that Oedipus is, all along, the person he is looking for, and the irony of the play places him in the role of detective when it is himself who is the criminal. His gradual realisation of this fact displays the tragedy of the play. He is trapped by fate and the gods in the position of having brought down the plague on his own people through his unknown sin of having killed the former king of Thebes, who also happened to have been his father. Oedipus is therefore an unwitting victim of circumstances beyond his control, and his identity is exposed by himself in spite of himself.