as exceptions, only on propositions that are intended as lawlike statements of general applicability. Hence if we cannot define a general rule that would justify the exception, we should indeed consider the original hypothesis as falsified.
None of these maxims can tell us which hypotheses to propose when we cannot draw on empirically validated theoretical models. For that we need an orienting framework that provides guidance to potentially relevant factors, causal mechanisms, and contextual conditions. In the social sciences, there is a wide variety of such orienting frameworks (usually labeled theories) -- from macro-level systems theories, materialist theories, and structuralist theories through hermeneutic and social-constructionist theories and varieties of rational-choice theories all the way to behavioralist learning theories, and many more. Useful and illustrative overviews are readily available (e.g., Lave/ March 1975; Green- stein/ Polsby 1975; Little 1991; Finifter 1993), and I will not add to them here. Instead, this book is intended to explicate and illustrate one particular framework that Renate Mayntz and I have developed over the years and applied in empirical studies of policy formation and policy implementation inside government institutions ( Mayntz/ Scharpf 1975; Scharpf/ Reissert/ Schnabel 1976; Mayntz 1980; 1983), of policy interactions among governments, unions, and central banks ( Scharpf 1991a), and of governance structures and processes in a variety of service sectors (such as health care, telecommunications, and research and development) that are characterized by high levels of state involvement ( Mayntz/ Scharpf 1995b). This framework of actor-centered institutionalism is characterized by its giving equal weight to the strategic actions and interactions of purposeful and resourceful individual and corporate actors and to the enabling, constraining, and shaping effects of given (but variable) institutional structures and institutionalized norms. Its elaboration will be a major purpose of this book. An overview will be presented in the following chapter.