<P> Catharsis ( from Greek κάθαρσις katharsis meaning `` 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 . It is a metaphor originally used by Aristotle in the Poetics , comparing the effects of tragedy on the mind of a spectator to the effect of a cathartic on the body . </P>
who said the function of tragedy is to produce the katharsis of pity and fear
Aristotle