"Most ancient Greek plays were intended as a form of political speech, performed at official state functions, and paid for by city," he said. "They were intended to be discussions of civic values. What does it mean to be a citizen? Where does duty lie? Can personal responsibilities be higher than the law?

"They're the same tough questions we have to face today. What does it mean to be a citizen, and obey the state, even when you might think the state is wrong?"

His famous connection between "pity and fear" and "catharsis" developed into one of Western philosophy's greatest questions: why is it that people are drawn to watching tragic heroes suffer horrible fates? Aristotle's ideas revolve around three crucial effects:

First, the audience develops an emotional attachment to the tragic hero; second, the audience fears what may befall the hero; and finally (after misfortune strikes) the audience pities the suffering hero.