Joseph Campbell:

The Sphinx in the Oedipus story is not the Egyptian Sphinx, but a female form with the wings of a bird, the body of an animal, and the breast, neck, and face of a woman. What she represents is the destiny of all life. She has sent a plague over the land, and to life the plague, the hero has to answer the riddle that she presents: "What is it that walks on four legs, then on two legs, and then on three?" The answer is "Man." The child creeps about on four legs, the adult walks on two, and the aged walk with a cane.

The riddle of the Sphinx is the image of life itself through time--childhood, maturity, age, and death. When without fear you have faced and accepted the riddle of the Sphinx, death has no further hold on you, and the curse of the Sphinx disappears. The conquest of the fear of death is the recovery of life's joy.
(The Power of Myth, 151-152)

Hubris: This is the Greek notion concerning arrogance from pride or passion -- a human being not knowing his or her place as a mere human being.

Tragic is the best of dramatic; no solution, period. We trace it from the Greeks all the way to Beckett or Miller. According to existentialists, our life is tragic, in principle -- and that is what makes us alive and "human." The same with mortality. Tragic hero addresses himself to gods, not mortals. This "dialogue" make us equal to God (and in my opinion higher than gods).

edipus Rex is notable for its use of dramatic irony: everybody in the audience knows from the start that Oedipus himself is the guilty party he seeks out for punishment. The viewers' enjoyment comes as they see and hear the facts accumulate, bit by bit, until it suddenly dawns on Oedipus that he is his father's murderer. The irony is heightened by blind Teiresias' many tauntings and the chorus' musical references to "seeing the light" Oedipus, though his physical eyes can see, is blind to the truth; and when he finally does come to see the truth, ironically, he blinds himself.