ABSTRACT
Cybernetics, or systems theory, is a complex and rapidly expanding discipline which it would be quite impossible to condense into this short section. The excellent elementary textbooks by Ashby (1956) and by Wiener (1948) describe the basis which we need for our purposes and this sketch amounts to no more than an imperfect outline intended to acquaint the reader with this kind of approach. An exhortation to go first to these and other primary sources (e.g. Bertalanffy 1950, 1969; Hall and Fagan 1956; Miller 1965; Buckley 1967, 1968) cannot be emphasized too strongly.
