Robert Boyle's air-pump experiments in 1659 provoked a lively debate over the possibility of a vacuum. The air-pump, a complicated and expensive device, became an emblem of the new experimental science that was promoted by the Royal Society. However, the philosopher Thomas Hobbes challenged both the validity of Boyle’s experiment and the philosophical foundations of this new approach to science. In their controversial book Leviathan and the Air-Pump (1985) Steven Shapin and Simon Schaffer took up Hobbes’s case, arguing that experimental findings depend for their validity on the scientific culture in which they are made. David Wootton (Anniversary Professor of History, University of York) reviews this controversy and present a new view of the dispute between Boyle and Hobbes. His presentation is followed by a reply from Robert Boyle's biographer Michael Hunter (Emeritus Professor of History, Birkbeck). The discussion is chaired by Ritchie Robertson (Taylor Professor of the German, University of Oxford).