KARL W. SCHWEIZER is Professor of History, New Jersey Institute of Technology, Newark, USA. He has published numerous books on diplomatic history, including England, Prussia and the Seven Years War (1989); and War, Politics and Diplomacy (2001). Further publications include the Art of Diplomacy (1994); Francois de Calli?res: Diplomat and Man of Letters (1995); and Lord Chatham (1993). A former Ph.D student of Butterfield, he has also edited the latter's previously unpublished essays on the History of Science (1998), wrote the entry on Butterfield for t