Karen Armstrong, one of the world's leading thinkers about religion, gives the Free Thinking Lecture, arguing that, in the current global situation, a recognition of how little we know is the only way to peace. She talks to Rana Mitter and takes questions from the audience. Recorded on 31.10.14 in front of an audience at BBC Radio 3's Free Thinking Festival of Ideas 2014 from Sage Gateshead.