Since the early 1960s there has been a growing interest in examining the concepts used by scientists in general and social scientists in particular. This is part of a more general tendency towards critical self-reflection within science. Just as natural scientists come increasingly to worry about the moral and practical implications of research in nuclear physics or molecular biology, and social scientists worry about their possible complicity in the military-industrial complex or in the reproduction of bourgeois ideology, so their worries also focus, more precisely, on the validity of their own assumptions, theoretical frameworks, etc. These anxieties are perhaps more extreme in the social sciences, where we may wonder, in moments of despair, whether our concepts and theories give us any sort of grip at all on the world. We are told by outsiders that we are neither genuine scientists nor genuine humanistic scholars; that we not only use a hermetic and rebarbative jargon but that this jargon, unlike that of natural science, is also gratuitous because the propositions expressed in it are no more than glorified common sense.