Looking back at some of the stories that have been in the news during this series of Moral Maze you could be forgiven for despairing of humanity. The suspected firebombing by Jewish settlers killing a Palestinian baby, the white supremacist who shot dead nine people at a church in South Carolina and where to start with so-called IS? Public stoning, mass executions and lessons in beheading for school children are just some of their stock-in-trade. Faced with such a litany of horrors it's tempting to reach for the word "evil" - nothing else quite does justice to the enormity of this kind of barbarity. If we can comfortably categorise an action as evil, what about the people who carried them out? Are they evil too? The problem of evil has long exercised theologians and moral philosophers. As our understanding of psychology and the neurosciences has developed what role should the notion of evil have in our moral, political, and legal thinking? Is evil an out-dated, redundant superstition which should be abandoned? Are we all, given sufficient provocation or circumstance, capable of committing evil acts? And if that is the case is there no horror which cannot be explained away? If we abandon the concept of evil what does that do to the idea of free will? Without evil would we drift into moral relativism? Or is the charge of being evil an easy get out for us all? By suggesting that evil is something alien and other, something of which we are possessed, that takes us over, it conveniently absolves us of the deeply unpleasant task of recognising that these people are part of our world. On the six hundredth and sixty-sixth edition of the programme the Moral Maze looks at the problem of evil.