I am greatly indebted to the German Fulbright Commission, and its Director, Dr Ulrich Littmann, for their generous support from September 1988 until February 1989, during which time I completed this paper. My gratitude also extends to the Zentralinstitut für sozialwissenschaftliche Forschung of the Free University of West Berlin, and its Directors Dr Dietrich Herzog and Dr Hans-Dieter Klingemann, who supplied me with both comfortable working conditions and a stimulating intellectual atmosphere.