Many of our global problems - from climate change to terrorism - require international not local solutions. Yet the world is increasingly fractured by nationalism. The political scientist, David Held, has a new book which explores cosmopolitan values. He tells Laurie Taylor why we should regard ourselves as citizens of the world rather than members of nations. Also, should we take responsibility for our own health, bodies and nutrition? Steven Shapin, Professor of the History of Science, talks about Dietetics - a branch of traditional western medicine which sought to prevent illness rather than find a cure. Originating in the 2nd century it held that good health reflected a virtuous life. This moral approach to the body died out with the advent of modern science but may now be enjoying a revival.

Producer: Jayne Egerton.