The most promising lines of development of theory in the sociological and most immediately related fields, particularly the psychological and cultural, therefore, seem to be two-fold. One major direction is the theoretical elaboration and refinement of structural-functional analysis of social systems, including the relevant problems of motivation and their relation to cultural patterns. In this process, the structure of social action provides a basic frame of reference, and aspects of it become of direct substantive importance at many specific points. The main theoretical task, however, is more than a refinement of the conceptual scheme of the presently reprinted book - it involves transition and translation to a different level and focus of theoretical systematization.