Melvyn Bragg and guests discuss the American philosophy of pragmatism. A pragmatist "turns away from abstraction and insufficiency, from verbal solutions, from bad apriori reasons, from fixed principles, closed systems, and pretended absolutes and origins. He turns towards concreteness and adequacy, towards facts, towards action and towards power". A quote from William James' 1907 treatise Pragmatism: A New Name for Some Old Ways of Thinking. William James, along with John Dewey and Charles Sanders Peirce, was the founder of an American philosophical movement which flowered during the last thirty years of the nineteenth century and the first twenty years of the 20th century. It purported that knowledge is only meaningful when coupled with action. Nothing is true or false - it either works or it doesn't. It was a philosophy which was deeply embedded in the reality of life, concerned firstly with the individual's direct experience of the world he inhabited. In essence, practical application was all. But how did Pragmatism harness the huge scientific leap forward that had come with Charles Darwin's ideas on evolution? And how did this dynamic new philosophy challenge the doubts expressed by the Sceptics about the nature and extent of knowledge? Did Pragmatism influence the economic and political ascendancy of America in the early 20th century? And did it also pave the way for the contemporary preoccupation with post-modernism? With A C Grayling, Professor of Applied Philosophy at Birkbeck College, University of London and a Fellow of St Anne's College, Oxford; Julian Baggini, editor of The Philosophers' Magazine; Miranda Fricker, Lecturer in Philosophy at Birkbeck College, University of London.

Melvyn Bragg and guests discuss the religious orders of the Dominicans and the Franciscans, known as the Blackfriars and Greyfriars. "Just as it is better to light up others than to shine alone, it is better to share the fruits of one's contemplation with others than to contemplate in solitude". Thus St Thomas Aquinas described his vocation, not only as a teacher, but also as a Dominican friar and philosopher at the University of Paris. In the 13th century, the religious orders of the Dominicans and the Franciscans were a great force for change in Catholic Europe. They thrived in the emerging towns and cities of the High Middle Ages, leading crusades and changing the way the Church dealt with heretics. They were the evangelists who transformed the Church's preaching of the Christian message to the people. On top of all this, these two orders were also responsible for reconciling Classical and Christian philosophy; their studies of Aristotle paved the way for the Renaissance. They also managed to change the curriculum at the universities of Paris and Oxford. But the Blackfriars and the Greyfriars did not come from the great monasteries of the time; they started out as itinerant preachers surviving upon the charity of the faithful. So how did these two orders come to dominate the spiritual and academic life of the 13th century, and how did they manage to accumulate such huge wealth while professing allegiance to lives of poverty? With Henrietta Leyser, medieval historian and Fellow of St Peter's College, Oxford; Alexander Murray, medieval historian and Emeritus Fellow of University College, Oxford; Anthony Kenny, philosopher and former Master of Balliol College, Oxford.

Melvyn Bragg and guests discuss the unique properties of asteroids. They used to be regarded as the 'vermin of the solar system', irritating rubble that got in the way of astronomers trying to study more interesting phenomena. It was difficult or even impossible for an observer of asteroids to book time using the world's best telescopes, because they were regarded as unspectacular objects that could tell us little about the origins of the universe. However, that has all changed. It is now thought that asteroids are the unused building blocks of planets, 'pristine material' that has remained chemically unchanged since the creation of the solar system; a snapshot of matter at the beginning of time. At the moment the Japanese probe Hayabusa is 180 million miles away, pinned to the back of the asteroid Itokawa, attempting to gain our first samples of the chemical composition of an asteroid. Why did asteroids fail to form planets? How do they differ from their celestial cousins, the comets? And are either of them likely to create another impact on planet Earth? With Monica Grady, Professor of Planetary and Space Sciences, Open University; Carolin Crawford, Royal Society Research Fellow, University of Cambridge; John Zarnecki, Professor of Space Science, Open University.

Melvyn Bragg and guests discuss Samuel Johnson, a giant of 18th century literature. “There is no arguing with Johnson, for when his pistol misses fire, he knocks you down with the butt of it." The poet Oliver Goldsmith was not alone in falling victim to the bludgeoning wit of Samuel Johnson. The greatest luminaries of 18th century England, including the painter Joshua Reynolds, the philosopher Edmund Burke and the politician Charles James Fox, all deferred to him... happily or otherwise. Samuel Johnson was credited with defining English literature with his Lives of the Poets and his edition of Shakespeare, and of defining English language with his Dictionary. Yet despite those lofty acclamations he failed to get a degree, claimed he had never finished a book, was an inveterate hack who told his friend James Boswell, "No man but a blockhead ever wrote, except for money". How did an Oxford drop-out become England's most famous and well connected man of letters? How did generations of readers come to see him as the father of English Literature? And why is he so little read today? With John Mullan, Professor of English at University College London; Jim McLaverty, Professor of English at Keele University; Judith Hawley, Senior Lecturer in English at Royal Holloway, University of London.

Melvyn Bragg and guests discuss the Cynics, the performance artists of philosophy. Eating live octopus with fresh lupins, performing intimate acts in public places and shouting at passers by from inside a barrel is behaviour not normally associated with philosophy. But the Cynics were different. They were determined to expose the meaninglessness of civilised life by action as well as by word. They slept rough, ate simply and gave their lectures in the market place. Perhaps surprisingly, their ideas and attitudes were immensely popular in the ancient world. But how coherent was cynicism as a philosophy? What was its influence on literature and politics and is there any truth to the contention that Jesus himself was influenced by the Cynics? With Angie Hobbs, Lecturer in Philosophy, University of Warwick; Miriam Griffin, Fellow of Somerville College, Oxford; John Moles, Professor of Latin, University of Newcastle.

Melvyn Bragg and guests discuss the rise of the mammals. The Cenozoic Era of Earth's history began 65 million years ago and runs to this day. It began with the extraordinary 'KT event', a supposed asteroid impact that destroyed the dinosaurs, and incorporates the break up of Pangaea, the enormous landmass that eventually formed the continents we know today. It is known as the 'Age of the Mammals', and it is the period in which warm-blooded, lactating, often furry animals diversified rapidly and spread across the globe on land and in the sea. According to evolutionary theory, what conditions created the opportunity for mammals to thrive? What environmental factors lead to the characteristics they share - and the features they don't? And how did they become the most intelligent class of animals on the planet? With Richard Corfield, Senior Lecturer in Earth Sciences at the Open University; Steve Jones, Professor of Genetics at University College London; Jane Francis, Professor of Palaeoclimatology at the University of Leeds.

Melvyn Bragg and guests discuss the Field of the Cloth of Gold, an extraordinary international party. In the spring of 1520 six thousand Englishmen and women packed their bags and followed their King across the sea to France. They weren't part of an invasion force but were attendants to King Henry VIII and travelling to take part in the greatest and most conspicuous display of wealth and culture that Europe had ever seen. They were met by Francis I of France and six thousand French noblemen and servants on English soil in Northern France and erected their temporary palaces, elaborate tents, jousting pavilions and golden fountains spewing forth red, white and claret wine in the Val D'Or. For just over two weeks they created a temporary town the size of Norwich, England's second city, on the 'Camp du Drap D'Or', or Field of the Cloth of Gold. What drove the French and the English to create such an extraordinary event? What did the two sides do when they got there, and what - if anything - was achieved? With Steven Gunn, Lecturer in Modern History at Oxford University; John Guy, Fellow of Clare College, University of Cambridge; Penny Roberts, Senior Lecturer in History at the University of Warwick.

Melvyn Bragg and guests discuss the history of magnetism. Pliny the Elder, in his Historia Naturalis, tells a story of a legendary Greek shepherd called Magnes who, while guiding his flock on Mount Ida, suddenly found it hard to move his feet. The nails of his sandals held fast to the rock beneath them, and the iron tip of his crook was strangely attracted to the boulders all around. Magnes had stumbled across the lodestone, or 'Magnetite', and discovered the phenomenon of magnetism. Plato was baffled by this strange force, as were Aristotle and Galen, and despite being used in navigation, supposedly suspended over the body of Mohammed and deployed in the pursuit of medical cures. St Thomas Aquinas thought magnets had souls. it was not until the late 16th century that any serious scientific attempt was made to explain the mystifying powers of the magnet. Descartes developed a particle theory of magnetism but the great Isaac Newton fought shy of the problem of what caused magnets to attract and repelWho pioneered the study of magnetism? What theories did they construct from its curious abilities and how was the power of the magnet brought out of the realm of magic and into the service of science? With Stephen Pumfrey, Senior Lecturer in the History of Science at the University of Lancaster; John Heilbron, Emeritus Professor of History at the University of California, Berkeley; Lisa Jardine, Professor of Renaissance Studies at Queen Mary, University of London.

Melvyn Bragg and guests discuss Karl Marx. "Workers of the World Unite! You have nothing to lose but your chains", "Religion is the opium of the people", and "From each according to his abilities, to each according to his needs". That should be enough for most of you to work out whom Radio 4 listeners have voted as their favourite philosopher: the winner of the In Our Time Greatest Philosopher Vote, chosen from 20 philosophers nominated by listeners and carried through on an electoral tidal wave of 28% of our 'first-past-the-post' vote is the communist theoretician, Karl Marx.So, when you strip away the Marxist-Leninism, the Soviet era and later Marxist theory, who was Karl Marx? Where does he stand in the history of philosophy? He wrote in his Theses on Feuerbach, "Philosophers have only interpreted the world in various ways, the point, however, is to change it" - which begs the question, is he really a philosopher at all?With Anthony Grayling, Professor of Philosophy at Birkbeck College, University of London; Francis Wheen, journalist and author of a biography of Karl Marx; Gareth Stedman Jones, Professor of Political Science at Cambridge University.

Melvyn Bragg and guests discuss Christopher Marlowe. In the prologue to The Jew of Malta Christopher Marlowe has Machiavel say:"I count religion but a childish toy, And hold there is no sin but ignorance. Birds of the air will tell of murders past! I am ashamed to hear such fooleries.Many will talk of title to a crown. What right had Caesar to the empire? Might first made kings, and laws were then most sure When, like the Draco's, they were writ in blood."A forger, a brawler, a spy, a homosexual and accused of atheism but above all a playwright and poet, Christopher Marlowe was the most celebrated writer of his generation, bringing Tamburlaine, Faustus and The Jew of Malta to the stage and far outshining William Shakespeare during his lifetime. Then came his mysterious death at 29, days before he was due to appear on trial accused of heresy. Was he stabbed in an argument over a bill? Was he assassinated? And how does his work measure up to Shakespeare, a man who paid generous tribute and some say stole some of his best lines? Was Marlowe assassinated by the Elizabethan state? How subversive was his literary work? And had he lived as long as his contemporary Shakespeare, how would he have compared?With Katherine Duncan-Jones, Senior Research Fellow in the English Faculty of Oxford University; Jonathan Bate, Professor of English Literature, University of Warwick; Emma Smith, Lecturer in English, Oxford University.