Anne McElvoy interviews one of the world's great thinkers - Nobel prize-winning economist Amartya Sen. Born in Bengal before Indian independence, he witnessed the 1943 famine at first hand. In his new book The Idea of Justice, Sen constructs a new theory of justice, not from abstract ideals or notions of what perfect institutions and rules might be, but from what the results of a system are practically. He highlights the importance of public reasoning and argues that there is no such thing as perfect justice, only manifest injustices which we should try to overcome in our communities. Playwright Mark Ravenhill discusses why some of his colleagues in the theatre world are more popular overseas than in Britain. Although he is feted as a writer here, he has said he doesn't make a living from UK productions of his plays and he needs the royalties from Europe to pay his rent; other writers like Edward Bond and Sarah Kane have the same experience. Richard English is professor of politics at Queens University Belfast and author of Terrorism - How to Respond. Drawing on a wide range of case studies, he argues that we have as yet failed to understand terrorism properly. He believes that the answer to 21st-century terrorism lies in its history and by drawing lessons from the IRA, ETA and the German Red Army, as well as more recent Islamist groups. He explains to Anne why such violence emerges, how it is sustained, and how and why it ends. And as part of a series on artists' flaws, John Deathridge talks about Schumann, who had struggled with playing the piano because his hands were too weak.