'System' is the concept that refers both to a complex of interdependencies between parts, components, and processes, that involves discernible regularities of relationships, and to a similar type of interdependency between such a complex and its surrounding environment.

— Talcott Parsons, Systems Analysis: Social Systems (1968)

Parsons's entry in the International Encyclopedia of the Social Sciences, as cited by Ida R. Hoos (1972).

Topics: complexity