Aristotle built upon questions raised by his teacher Plato about the nature and purpose of literature. He differentiated between the three main types of Greek poetry - epic, tragic, and lyric poetry. Aristotle focused his analysis on tragedy, believing it contained all the elements of epic as well as its own unique qualities. According to Aristotle, a tragedy is comprised of plot, character, diction, thought, spectacle, and song, and features a tragic hero whose flawed judgment or hamartia leads to their downfall.