the so-called "purification theory" in literary theory.

On the effect of tragedy, Aristotle put forward the "purification theory", that is, tragedy makes people feel pity and fear and clears the depressed mood. Through the indulgence and catharsis of emotions, people's mood will finally be restored to calm and their hearts will be purified.

Tragedy was strongly advocated in ancient Greece, while comedy was even forbidden by the government.