"Denial is about hiding from the truth. Denialism builds a 'new and better' truth." Keith Kahn-Harris, a researcher and lecturer at the University of London, says the challenge of confronting denialism is that denialists don't see themselves as rejecters of truth. They see themselves as having the actual truth, one that the rest of us can't see or accept. Keith Kahn-Harris in conversation with IDEAS producer Naheed Mustafa.