Aristotle was Plato's most famous student. He wrote Poetics, which analyzed Greek literature and established the first principles of literary criticism. In Poetics, Aristotle defines tragedy as an imitation of a serious action that evokes emotions of pity and fear and achieves a catharsis of these emotions. He identifies six elements of tragedy - plot, character, thought, diction, song, and spectacle. Aristotle devotes significant analysis to tragedy, considering it the highest form of poetry. He establishes that tragedy's purpose is to please audiences through an artistic and emotional experience.