Introductory remarks In The Structure of Social Action (1937), Talcott Parsons articulated a theory of action the fundamental strategy of which corresponds to that of Kant’s critical philosophy and the development of which up to Action Theory and the Human Condition (1978) must be understood as a systematic elaboration of this basic Kantian perspective. The hallmark of this perspective is the assumption that every action is to be understood as the product of a certain relation between analytically differentiable spheres or subsystems. These subsystems of human action are of two basic kinds: those with a regulative function and those with a dynamizing function. The paradigm of this distinction is found in the distinctions between the categories of the understanding and sense perception, between the categorical imperative and practical judgements, and between aesthetic categories and aesthetic sensation which we find in the critical philosophy of Kant.1 It is only through the interpenetration of these spheres that cognitive, moral, or aesthetic experience can constitute itself. However, interpenetration is only one of many possible relations which may obtain between analytically differentiable subsystems of action. Between these subsystems there exist fundamental tensions. Max Weber’s typology of the relations between religious ethics and the world provides us with a ready set of categories for thinking about the various ways in which these can be eased: the accommodation of the potentially regulative subsystem to the dynamic subsystem, their mutual isolation, their interpenetration, the onesided constriction of the potentially dynamizing subsystem by the regulative subsystem.2 Interpenetration, however, is that form of relation through which opposed spheres or subsystems can both expand without thereby creating mutual interference. Interpenetration is the mechanism by which the potential of every system is converted into actuality; it is the mechanism of self-realization and evolution.