Catharsis

Catharsis (from Greek κάθαρσις, "purification" or "cleansing") is the purification and purgation of emotions—particularly pity and fear—through art or any extreme change in emotion that results in renewal and restoration.

• A tragedy, then, is the imitation of an action that is serious and also, as having magnitude, complete in itself; in language ... not in a narrative form; with incidents arousing pity and fear, wherewith to accomplish its catharsis of such emotions.
  • Aristotle, Poetics, 1449b24 ff.

• The establishment does everything in itspower to ensure that revolutionary rage is redirected into empty outlets which provide pressure releases for desires that could become dangerous if allowed to progress.
  • George L. Jackson, Blood in My Eye (1971), p. 186