Why do people do evil things? We hear from Yale psychologist Paul Bloom and journalist Graeme Wood about the nature of evil. Bloom studies morality in babies, children, and adults. Wood immersed himself in ISIS, readings the terror group’s propaganda and conversing with its members, in order to write the book The Way of Strangers: Encounters with the Islamic State. Graeme explains that ISIS members aren’t crazy but are driven to do horrific evil deeds, like murder and rape. Why do they carry out these evils? And what about smaller-scale evil acts like cheating a lying? Is it enough to define evil as having a sense of right and wrong? Bloom and Wood’s conversation touches on philosophy, religion, and politics.