In Oedipus Rex, does Oedipus keep his promise to rid the city of the plague?Did he in fact do everything possible?
Thebes is suffering from a plague, we hear right at the very start of the play. People are suffering, people are dying, women's children are dying. Oedipus is the king of Thebes. It is his duty to do something about it, and he swears to find the cause of it (a man, Laius' murderer, according to the Delphic Oracle) and remove them. Even, he says, if that cause turns out to be him.
It's not an accident, or a mistake, that Oedipus discovers himself. He is determined, no matter the cost to himself, to do his duty as king. The mistake which brings about his tragedy comes before the play starts when he kills a stranger at a crossroads. Oedipus' insistence on solving riddles, on finding the solution to problems, and on being a good king and ridding Thebes of its plague leads him, ever more painfully throughout the action of the play, towards his dreadful realisation that he has, in fact, killed his father and married his mother.
Even when Jocasta begs him to go no further with his investigation, begs him to stop - at the moment when she realises what has happened, he ignores her - the wife that he loves. Teiresias the prophet is rudely cast aside when he advises Oedipus to stop. So yes, Oedipus does keep his promise. He removes the cause of the plague - and with it, his sight, his happiness, his wife, and his life.