Does 'evil' exist?

We think we've grown out of the belief in evil. It's not in our genes and people don't get possessed. But across media and culture, from Star Wars to Isis, evil still holds us strangely captive. Why does the devil seem to have the best tunes?  Is the battle between good and evil an essential part of being human after all? Cambridge Psychologist Simon Baron-Cohen joins philosopher Rebecca Roache and The Idea of Evil author Peter Dews to investigate the strangeness of evil. This debate was sponsored by the British Humanist Association.