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.