A contrast or discrepancy between what is said and what is meant or between what happens and what is expected to happen in life and in literature. In verbal irony, characters say the opposite of what they mean. In irony of circumstance or situation, the opposite of what is expected occurs. In dramatic irony, a character speaks in ignorance of a situation or event known to the audience or to the other characters. Flannery O'Connor's short stories employ all these forms of irony, as does Poe's "Cask of Amontillado."
The science revolution attributed to Thales began gaining political force, and this play offered a warning to the new thinkers. Kitto interprets the play as Sophocles' retort to the sophists , by dramatizing a situation in which humans face undeserved suffering through no fault of their own, but despite the apparent randomness of the events, the fact that they have been prophesied by the gods implies that the events are not random, despite the reasons being beyond human comprehension.  Through the play, according to Kitto, Sophocles declares "that it is wrong, in the face of the incomprehensible and unmoral, to deny the moral laws and accept chaos. What is right is to recognize facts and not delude ourselves. The universe is a unity; if, sometimes, we can see neither rhyme nor reason in it we should not suppose it is random. There is so much that we cannot know and cannot control that we should not think and behave as if we do know and can control.