Melvyn Bragg and guests discuss the vexing issue of human nature. Some argue that we are born as blank slates and our natures are defined by upbringing, experience, culture and the ideas of our time. Others believe that human nature is innate and pre-destined, regardless of time and place. Is there really such a thing as human nature? And, if there is, can it be changed? Does the truth about human nature mean we should stop striving for progress, or should it give us cause for optimism? How important is the human race in the wider scheme of things? With Steven Pinker, Professor of Psychology and Director of the Centre of Cognitive Neuroscience, Massachusetts Institute of Technology; Janet Radcliffe Richards, Philosopher, Reader in Bioethics, University College London; John Gray, Professor of European Thought, London School of Economics.

Melvyn Bragg and guests discuss the role which architecture has played in our public life throughout history, whether in homage to an individual or as a monument to an institution or ideology, has always been a potent symbol of wealth, status and power. From castles to cathedrals, from the pyramids to Canary Wharf, architecture has always served to glorify in some way the animating ideal of the time. Why is architecture such a powerful form of expression? Have architects concerned themselves mainly with the masses, or restricted their designs to the demands and aspirations of the elite? What can a country's buildings tell us about its ideas of its own past and present identity? With Adrian Tinniswood, Architectural historian; Gavin Stamp, Senior Lecturer, Mackintosh School of Architecture, Glasgow School of Art; Gillian Darley, Architectural historian and biographer of John Soane.

Melvyn Bragg and guests discuss the origin of the concept and historical role of the scientist. The word "science" first appeared in the English language in 1340 and ever since its meaning has been in a state of flux. The notion of "the scientist" has had a similarly evolving history. For some, "the scientist" does not truly appear until after the Renaissance, others put its emergence much later than that. When did the words and concepts we recognise today take on their contemporary meaning? How has the role of the scientist, and our understanding of it, changed? Has science always been a rival to religion, or was it once an ally? And how has the scientist been perceived by the wider world – as a modern saint, the "priest of reason", or as a terrifying and amoral menace - the "mad scientist" of film and literature? With John Gribbin, Visiting Fellow in Astronomy, University of Sussex; Patricia Fara, Lecturer on the History and Philosophy of Science, Cambridge University; Hugh Pennington, Head of the Department of Medical Microbiology, University of Aberdeen.

Melvyn Bragg and guests discuss slavery and empire; two themes that run right through this country’s history. Britain’s imperial project dominated at least the last three centuries of our national life. Its advocates claim it was a civilising mission by which Britain spread enlightenment and improvement across the globe. Opponents have long seen it as a brutal business, with Britons cast as cruel oppressors out to exploit a conquered world. Is our imperial history so clear cut? What if Britons were themselves captives, either as prisoners of an imperial enterprise that sucked them in, generation after generation or, in some startling cases, as slaves to foreign peoples? Is slavery an inevitable part of empire: does it come with the territory? And how did Britain finally shake it off? With Linda Colley, School Professor of History, LSE; Catherine Hall, Professor of Modern British Social and Cultural History, University College London; Felipe Fernandez Armesto, Professorial Research Fellow, Queen Mary College London.

Melvyn Bragg and guests discuss the role history and heritage have played in the formation of the British national identity. Historians have often maintained a guarded relationship with the so-called ¨heritage industry¨, believing that it presents a distorted version of national life: a Merrie England that is politically acceptable and economically rewarding. History, in contrast, is held to reveal the truth about the past - objectively and scientifically. Our understanding of history changed since the 19th century and, as historians interpret our time and our society, so will our ideas of heritage and history.With David Cannadine, Director of the University of London's Institute of Historical Research; Miri Rubin, Professor of European History at Queen Mary, University of London; Peter Mandler, Fellow in History, Gonville and Caius College, Cambridge.

Melvyn Bragg and guests discuss the impact of politics on psychoanalysis. The 20th century saw the birth and rise of psychoanalysis. Sigmund Freud led people to think about how the mind functioned and how our behaviour might be understood through the process of working with a psychoanalyst, either one-to-one or in a group. Freud thought a lot about this process and in 1922 he published Group Psychology and the Analysis of the Ego, in which he pronounced that the group "wants to be ruled and oppressed and to fear its masters." He was writing at a time when ideas about rules and oppression were much discussed because the 20th century was also a century of fascism, totalitarianism and dictatorship. Freud died in 1939, just as a wave of despotism was sweeping across Europe. To what extent does psychoanalysis function by the rules of a dictatorship and to what extent does it function like a democracy? Is there a part of us that craves dictatorship and, if so, why? Is there a war going on in our own minds between ideas that we allow in to our consciousness and other ideas that we repress? With Adam Phillips, general editor of the new Penguin translations of Freud; Sally Alexander, Professor of History, Goldsmiths College, University of London; Malcolm Bowie, Marshal Foch Professor of French Literature and Fellow, All Souls College, Oxford.

Melvyn Bragg considers what it is to be free and how freedom became such a powerful value. Freedom has been a subject of enquiry for philosophers, theologians and politicians who have attempted to define the conditions required for humans to be free, not just in their minds but in the wider world. Some have argued that man is naturally free and no laws should confine his liberty. Others have countered that laws are the only way to preserve freedom; they protect us from the slavery of the abyss. The very idea of freedom is riddled with constraints, limitations and qualifications, yet it is seen by many as the most basic of human rights and for some as a principle worth fighting and dying for. With John Keane, Professor of Politics, University of Westminster; Bernard Williams, Professor of Philosophy, University of California; Annabel Brett, Lecturer in History, University of Cambridge.

Melvyn Bragg and guests discuss how a dominant power can exert a cultural influence on its empire. An empire rests on many things: powerful armies, good administration and strong leadership, but perhaps its greatest weapon lies in the domain of culture. Culture governs every aspect of our lives: our dress sense and manners, our art and architecture, our education, law and philosophy. To govern culture, it seems, is to govern the world. But what is cultural imperialism? Can it be distinguished from cultural influence? Does it really change the way we think and should we try to prevent it even if it does?With Linda Colley, School Professor of History, London School of Economics; Phillip Dodd, Director, Institute of Contemporary Arts; Mary Beard, Reader in Classics, Cambridge University.

Melvyn Bragg and guests discuss Richard Wagner who, perhaps more than any other composer, would seem to capture the greatest triumphs and most terrifying excesses of the German spirit. He lived as modern Germany was being born and his republicanism led to exile and nearly execution. He was a mentor of Nietzsche and a disciple of Schopenhauer and changed the face of opera perhaps more than any other single person. Wagner conducted several orchestras and numerous affairs, suffered poverty and rejection but was finally showered with wealth by King Ludwig II. When the Nazis played his music in the death camps was it a fitting tribute to a gross anti-Semite or a travesty for a man who believed in redemption through love and social equality? We ask to what extent can Wagner be typified as demonstrating the German spirit and what were his views on the function of art? With John Deathridge, King Edward the Seventh Professor of Music, Kings College London; Lucy Beckett, Author of Richard Wagner: Parsifal; Michael Tanner, Philosopher and author of Wagner and Nietzsche.

Melvyn Bragg and guests discuss the myths and harsh reality of the 19th century American pioneers. In 1845 the editor of The New York Morning News wrote that it was the "manifest destiny" of the United States "to overspread and to posses the whole of the continent which providence has given us for the development of the great experiment of liberty and federated self-government entrusted to us." With such phrases ringing in their ears the pioneering wagon trains rolled west into the uncharted wilderness of the American continent. Thus began the wagon trails that cut a path beyond the frontier to California and Oregon, a path soon to be followed by gold prospectors, entrepreneurs, cowboys and finally the US army itself. But what propelled them all to go? Was it an "experiment of liberty", or the promise of a better life? Does the story of the frontier help us to understand the American psyche and do our ideas about the American West owe more to the mythology of John Wayne movies than to the history of the real trailblazers? With Frank McLynn, Visiting Professor in the Department of Literature, University of Strathclyde; Jenni Calder, Author of There Must Be a Lone Ranger: The myth and reality of the American Wild West; Christopher Frayling, Rector of the Royal College of Art.