And all these images, like the plot, like the hero, have what Aristotle called their peripeteia, their reversal. The hunter catches a dreadful prey, the seaman steers his ship into an unspeakable harbor—“one and the same wide harbor served you / son and father both” (1335-36)—the plowman sows and reaps a fearful harvest, the investigator finds the criminal and the judge convicts him—they are all the same man—the revealer turns into the thing revealed, the finder into the thing found, the calculator finds he is himself the solution of the equation and the physician discovers that he is the disease. The catastrophe of the tragic hero thus becomes the catastrophe of fifth-century man; all his furious energy and intellectual daring drive him on to this terrible discovery of his fundamental ignorance—he is not the measure of all things but the thing measured and found wanting.

Bernard Knox, introduction to Sophocles, Oedipus Rex, translated by Robert Fagles