Aristotle's theory of tragic drama was that it assisted order in
the social body by enabling the purging (catharsis) of unhealthy
emotions, especially by evoking the emotions of pity and fear.
Citation:
Editors. "Catharsis".
The Literary Encyclopedia. First published 01 November 2001
[http://www.litencyc.com/php/stopics.php?rec=true&UID=170, accessed 19 June 2013.]