Melvyn Bragg and guests discuss what drove the British Empire, especially in Victoria’s century. Was it science, more specifically, the science of plants, of agriculture, a scientific notion of nature and the improvement of nature? Was this seemingly rather adjacent notion - that the source of Empire can be found in Kew Gardens, Royal, Botanical, rather than in the muzzle of a gun or in the purse of a plunderer or in the consciousness of a conqueror - was science “the force that was with us?” Francis Bacon said of the Irish in 1603, “We shall reclaim them from their barbarous manners…populate plant and make civil all the provinces of that kingdom ..as we are persuaded that it is one of the chief causes for which God hath brought us to the Imperial Crown of these Kingdoms”. Centuries later, at the height of the Empire, John Stuart Mill wrote in On Liberty: “Despotism is a legitimate mode of government in dealing with barbarians, provided the end be their improvement”. But - despotism aside - was this notion of ‘improvement’ really the driving force behind the Empire? And did the British Empire have any firm basis in believing that the ‘light of pure reason’ that it brought to its colonies was any brighter than the knowledge that existed before they came? With Richard Drayton, Professor of History at the University of Virginia and author of Nature’s Government: Science, Imperial Britain and the ‘Improvement’ of the World; Maria Misra, Lecturer in Modern History and fellow of Keble College Oxford; Ziauddin Sardar, Professor of Science and Technology Policy, Middlesex University.