"Interaction can be considered as a system, and the general theory of systems gives insight into the nature of interactional systems. General Systems Theory is not only a theory of biological, economic, or engineering systems. Despite their widely varying subject matter, these theories of particular systems have so many common conceptions that a more general theory has evolved which structures the similarities into formal isomorphies. ...'The isomorphy we have mentioned is a consequence of the fact that in certain aspects, corresponding abstractions and conceptual models can be applied to different phenomena. It is only in view of these aspects that system laws will apply.'
"Finally, one of the most significant characteristics of open systems is found in equifinal behavior, especially in contrast to the closed-system model. The final state of the closed system is completely determined by initial circumstances that can therefore be said to be the best explanation' of that system; in the case of the open system, however, organizational characteristics of the system can operate to achieve even the exterme case of total independence of initial conditions. The system is then its own best explanation, and the study of its present organization the appropriate methodolgy.
"Human interaction is described as a commmunication system, characterized by the properties of general systems: time as a variable, system-subsystem relations, wholeness, feedback, and equifinality. Ongoing interactional systems are seen as the natural focus for study of the long-term pragmatic impact of communicational phenomena. Limitation in general and the development of family rules in particular lead to a definition and illustration of the family as a rule-goverened system."