For Aristotle, Sophocles' writing of Oedipus' narrative fulfills much in way of the notions of tragedy that he outlines in Poetics. For Aristotle, great tragedy resides in the fulfillment of some essential characteristics. One of these is the idea of reversal, a dramatic situation in which character realizations revolve around understanding the truth from what was previously believed to be so. In the case of Oedipus' narrative, his reversal is seen when he realizes that who he thought he was is not who he really is. In this, Aristotle feels that Sophocles' work accomplishes a major tenet of tragedy. At the same time, Aristotelian notions of tragedy revolve around the embrace of a character who is not morally perfect, but not immoral by any means. They must achieve the right balance of "virtue" and "evil," something that Oedipus displays in his treatment of Tiresias and Creon, but also something shown in his own pathetic state. For Aristotle, the fulfillment of a solid and effective plot structure is one in which the audience "hears the tale told will thrill with horror and melt to pity at what takes place." This is accomplished in the ending where the structure of the plot has revealed at the perfect moment, a climax, the truth about the nature of Oedipus' reality. In these areas, a strong case can be made that Sophocles' work represents a good example of Aristotle's notion of tragedy.