A new history of ideas presented by Melvyn Bragg but told in many voices. Melvyn is joined by four guests with different backgrounds to discuss a really big question. This week the question is 'How do I tell wrong from right?' Helping him answer it are Neuro-psychologst Paul Broks, Philosopher Angie Hobbs, Theologian Giles Fraser and Lawyer Harry Potter. For the rest of the week Paul, Angie, Giles and Harry will take us further into the history of ideas about morality with programmes of their own. Between them they will examine the idea of conscience and moral intuitions, the relationship between morality and the law, whether moral systems can work on the battlefield and what the brain seems to do when we are making moral decisions.