The Joker in the Box or The Theory Form of the System

Compared with traditional theories, systems theory presents a deviation. It replaces causal explanation by functional explanation. This paper shows what scandalon is inherent in this substitution and elucidates some models (self-organization, dance, non-triviality, structural coupling) which put the explanatory principle to work. The paper concludes by showing how systems theory aims at a general concept of communication that not only means a passing on of knowledge but above all the tracing of ignorance. Overall, systems theory is presented as a joker dealing with the paradox that the system is never identical to itself as soon as it is considered as a function of itself and its environment. The system has to withdraw into the function it is a function of in order to enfold this paradox.