Aristotle considered Oedipus Rex to be a great play and a perfect tragedy because it followed the classical rules of tragedy, including the elements of hamartia (fatal flaw), anagnorisis (discovery), peripeteia (reversal of fortune) and catharsis (emotional purging). He believed that these elements combined together created a powerful experience for audiences that left them with a feeling of pity and fear. Additionally, Aristotle saw the play as an exploration into human nature and its capacity for both good and evil.