Complementarity is an epistemological principle derived from the subject – object or observer – system dichotomy, where each side requires a separate mode of description that is formally incompatible with and irreducible to the other, and where one mode of description alone does not provide comprehensive explanatory power. The classical physics paradigm, on which biological, social and psychological sciences are modelled, completely suppresses the observer or subject side of this dichotomy in order to claim unity and consistency in theory and objectivity in experimental observations. Quantum mechanical measurements have shown this paradigm to be untenable. Explanation of events requires both an objective, causal representation and a subjective, prescriptive representation that are complementary. The concepts of description and function in biological systems, and goals and policies in social systems, are found to have the same epistemological basis as the concept of measurement in physics. The concepts of rate-dependent and rate-independent processes are proposed as a necessary distinction for applying the principle of complementarity to explanations of physical, biological and social systems.

Five points are made: (1) Psychology is the science not only of the individual but also of humans in general. For example, mathematics and physics have been created by human beings, and this creation can be understood only in terms of/ human intelligence in its totality. (2) Psychology is a natural science, and, like every other science, it is built not only with what comes from the object but also with the structures constructed by the subject. (3) Psychology occupies a key position among the sciences because it explains the notions and operations used in the development of all the sciences. (4) It is impossible to dissociate psychology from epistemology. (5) Psychology, like all other sciences, can thrive only on interdisciplinary cooperation.

This paper summarizes the author’s work on the question of the autonomy of natural systems. A more precise characterization of autonomy is proposed, as well as its application to specific biological systems, its mathematical representation, and its impact on cognitive processes.

This paper provides a conceptual framework to accommodate important recent developments in immunology (genetic determination, cellular interactions, suppression). The basic idea is to look at the immune system as a closed network of interactions which self-determines its ongoing pattern of stability and its capacities of interaction with its environment. Thus, all immune events are understood as a form of self-recognition, and whatever falls outside this domain, shaped by genetics and ontogeny, is simply non-sensical. This paradigm, stemming from the ideas of Jerne, represents almost a logical inversion of the Burnetian idea of self-discrimination. A detailed discussion of the immunological evidence that substantiates this view is presented, together with some new concepts (eigenbehavior, cognitive domains). Although the paper is addressed to biologists and immunologists, we make extensive use of system-theoretic notions in a non-mathematical form (recursion, nets and trees, self-organization).

Key words: immune networks, models, biological, immunosuppression, anti-idiotipic antibodies, immunoregulation, recursion

In dieser Habilitationsschrift wird versucht, zur Darstellung des Erkenntnisprozesses drei Linien zusammenzubringen, die weithin als unvereinbar gelten: die Subjektivitätstheorie von Kant und Hegel, die naturwissenschaftlich orientierten Beiträge vor allem der Kybernetik und Informationstheorie und die Marxsche Theorie der “ersten geschichtlichen Tat”. Diese Vermittlung geschieht durch einen handlungstheoretischen Ansatz, in dem die arbeitsteilige oder gesellschaftliche Praxis als Wurzel der Erkenntnis vermittelnden Handlungsschemata begriffen wird. Die auf das Intra-Subjektive bezogene Darstellung dieser Handlungsschemata geht weitgehend auf Piaget zurück. Mit der Verschränkung dieser theoretischen Positionen wird der Gegenstandsbezug des erkennenden Subjekts, seine Beziehung auf Anderes und auf sich selbst geltend gemacht, ohne seine Naturund Gesellschaftswirklichkeit zu vernachlässigen, ohne ihr aber auch absolute Dominanz einzuräumen.