In sum, social actors knowledgeably and actively use, interpret and implement rule systems. They also creatively reform and transform them. In such w… - Tom R. Burns

In the most abstract sense, a system is a set of objects together with relationships among the objects. Such a definition implies that a system has properties, functions, and dynamics distinct from its constituent objects and relationships.

System theories have been applied to a wide spectrum of empirical cases and policy issues. Parsons and his followers, in particular, applied their systems theory to diverse empirical phenomena in sociology as well as in other disciplines: modernization, economics, politics, social order, industrialization and development, Fascism and McCarthyism, international relations, social change and evolution, complex organizations, health care, universities, religion, professions, small groups, and family as well as abstract questions such as the place of norms in maintaining social order both historically and cross-nationally. Marxian theory and dynamic system theories have also been applied to a spectrum of diverse empirical and policy subjects.

The rule systems governing transactions among agents in a defined sphere specify, to a greater or lesser extent, who participates (and who is excluded), who does what, when, where and how, and in relation to whom. ln particular, they define possible rights and obligations, including rules of command and obedience, governing specified categories of actors or roles vis a vis one another. The theory deals with the properties of social rule systems, their role in patterning social life, and the social and political processes whereby such systems are produced, maintained, and transformed as well as implemented in social action and interaction.