Aristotle argued that a tragedy had to have a tragic hero whose downfall was based on a "hamartia," or tragic flaw. This would be the seed of their destruction, and would bring them down from their high position. In many cases, this tragic flaw was pride or hubris, and in Oedipus this is no different. Note how he describes himself when he realises what the problem is with Thebes and what he needs to do as a result to help his people:
I'll start again--I'll bring it all to light myself! ...
Now you have me to fight for you, you'll see:
I am the land's avenger by all rights,
and Apollo's champion too.
Oedipus is shown he to be incredibly arrogant in the way that he describes himself and how he views himself as the single saviour his people will ever need. Spot how he refers to himself, using "I" repeatedly to emphasise his own belief in his talents and ability to uncover the past. Of course, this arrogance and self-belief is tragically what causes his own downfall and brings him to ruin, for it is his determination to "bring it all to light" himself that leads to his own discovery of his true identity. If he had not been so arrogant and sure of himself, perhaps he would still remain ignorant and happy. This play therefore is an example of a classical tragedy through the depiction of Oedipus as a tragic hero with his tragic flaw.