"Oedipus Rex" is a quite difficult play to interpret. A reader of Oedipus always remains confused as to what extent Oedipus himself is responsible for his downfall. There are certain facts in Oedipus' life for which his fate is more responsible than he. But, nonetheless, various traits of his own personality also contributed in his fall as well. Most of the critics agree upon the fact that Oedipus' inquisitive nature and pride had a very significant role to play in his downfall.
We see Oedipus as a just king in the beginning of the play. He appears to be a king who is much concerned with the problems of his subject. But as the play moves on, even in the very first act, we see him talking to Creon and the old priest in a proud tone. He times and again refers to solving the riddle, which was of course something to be proud of. But he exalted about the matter to an extent where it became a weakness of his. He could never get out of the shadow of pride in his intelligence. And it was in his pride that he spoke insultingly to the old priest and disgraced him. Consequently, the old priest had to say what he never wanted to speak of.
We see Oedipus as a just king in the beginning of the play. He appears to be a king who is much concerned with the problems of his subject. But as the play moves on, even in the very first act, we see him talking to Creon and the old priest in a proud tone. He times and again refers to solving the riddle, which was of course something to be proud of. But he exalted about the matter to an extent where it became a weakness of his. He could never get out of the shadow of pride in his intelligence. And it was in his pride that he spoke insultingly to the old priest and disgraced him. Consequently, the old priest had to say what he never wanted to speak of.