Aristotle was a Greek philosopher born in 384 BC who studied under Plato. In his work Poetics, he outlined his concept of tragedy. According to Aristotle, a tragedy must have unity of action, time, and place. It should evoke emotions of pity and fear in the audience and result in catharsis or purification. The tragic character should be neither perfectly good nor entirely evil, but realistic and consistent in their actions. The plot must depict a single, coherent action that leads to a change in fortune through probable and necessary events.