According to Aristotle (384-322 BC), tragedy is “an imitation of an action that is serious, complete, and of a certain magnitude” and which excites both pity and fear. The excitation of pity and fear in the viewer is the distinctive marker of tragedy. Without this excitation of pity and fear there is no tragedy. Pity, he says, is aroused by unmerited misfortune; fear by the misfortune of a man like ourselves.
One example of Greek tragedy is Sophocles’ Oedipus the King. Most are familiar with the basic plot of the tragedy, or at the very least how it ends. Oedipus, propelled by the inescapable power of fate, murders his father and marries his father. It evokes pity because his end is unmerited—he did not do anything to deserve it. It evokes fear because everyone (at least in the ancient Greek mind) is bound by fate.