An activity of the Primer Group


A Special Integration Group (SIG) of the
International Society for the Systems Sciences (ISSS)
originally SGSR, Society for General Systems Research.




Adapted from
Author: F. Heylighen, C. Joslyn,
Date : Nov. 1, 1992

What are Cybernetics and Systems Science?

What is Systems Theory?
Systems Theory: the transdisciplinary study of the abstract ORGANIZATION of phenomena, independent of their substance, type, or spatial or temporal scale of existence.

It investigates both the principles common to all complex entities, and the (usually mathematical) MODELS which can be used to describe them.

Systems theory was proposed in the 1940's by the biologist Ludwig von Bertalanffy (anthology: General Systems Theory, 1968), and furthered by Ross Ashby (Introduction to Cybernetics, 1956).

von Bertalanffy was both reacting against REDUCTIONISM and attempting to revive the UNITY OF SCIENCE. He emphasized that real systems are open to, and interact with, their environments, and that they can acquire qualitatively new properties through EMERGENCE, resulting in continual EVOLUTION. Rather than reducing an entity (e.g. the human body) to the properties of its parts or elements (e.g. organs or cells), systems theory focuses on the arrange ment of and RELATIONS between the parts which connect them into a whole (cf. HOLISM). This particular ORGANIZATION determines a SYSTEM, which is independent of the concrete substance of the elements (e.g. particles, cells, transistors, people, etc). Thus, the same concepts and principles of organization underlie the different disciplines (physics, biology, technology, sociology, etc.), providing a basis for their unification.

Systems concepts include: system-environment BOUNDARY, INPUT, OUTPUT, PROCESS, STATE, HIERARCHY, GOAL-DIRECTEDNESS, and INFORMATION. The developments of systems theory are diverse (Klir, Facets of Systems Science, 1991), including conceptual foundations and philosophy (e.g. the philosophies of Bunge, Bahm and Laszlo); mathematical modeling and INFORMATION THEORY (e.g. the work of Mesarovic and Klir); and practical applications. Mathematical systems theory arose from the development of isomorphies between the models of electrical circuits and other systems. Applications include engineering, computing, ecology, management, and family psychotherapy. Systems analysis, developed independently of systems theory, applies systems principles to aid a decision-maker with problems of identifying, reconstructing, optimizing, and controlling a system (usually a socio-technical organization), while taking into account multiple objectives, constraints and resources. It aims to specify possible courses of action, together with their risks, costs and benefits.

Systems theory is closely connected to CYBERNETICS, and also to SYSTEM DYNAMICS, which models changes in a NETWORK of coupled variables (e.g. the "world dynamics" models of Jay Forrester and the Club of Rome). Related ideas are used in the emerging "sciences of COMPLEXITY", studying SELF-ORGANIZATION and heterogeneous networks of interacting actors, and associated domains such as FAR-FROM-EQUILIBRIUM THERMODYNAMICS, CHAOTIC DYNAMICS, ARTIFICIAL LIFE, ARTIFICIAL INTELLIGENCE, NEURAL NETWORKS, and computer MODELING AND SIMULATION.

Francis Heylighen and Cliff Joslyn
Prepared for the Cambridge Dictionary of Philosophy.
(Copyright Cambridge University Press)