E. Durkheim, one of the co-founders of sociology, emphasized that realities can be understood as constructs of individuals and social systems. This individual and at the same time social construction of knowledge is the topic of this article. At the analytic level of individuals, reality constructs emerge as the result of individual processes of perception and thought. But these individuals were necessarily social because of their shared evolutionary past. Therefore they construct broadly similar ideas of what they see as “the” physico-chemical reality. In addition, they show evolved cognitive mechanisms that are socially important as behavioral dispositions (the ability to develop language and symbol manipulation, the capacity to deal with complex relationships of reciprocity, the ability to imitate and thus to organize teaching / learning contexts, or linking emotionality and sociality, etc.). Social systems can be understood as more or less stable units of interacting participants. This requires a relatively large and structured set of reality constructs shared by the members of the systems. These constructs of reality include at the level of societies descriptions both of the respective social reality and of the natural environment. However, this fundamental distinction between “social” and “natural” is to be understood as a secondary differentiation. It was necessarily created under the influence of the same evolutionary processes in which the first societies were formed. With the formation of societies, what unavoidably implies the “establishment” of shared reality-constructs as a necessary prerequisite for communication and cooperative action, the “overall reality” distributed via the plurality of individual cognitive processes also had to be included in this context. This “total reality” attains an existence independent of the individual knowledge of the members of a given society. Thus a level is created that is specific to human societies, the level of culture (especially the transmission of cognitive and behavioral knowledge through observation, non-verbal and verbal communication up to writing and finally to electronic media). The level of culture should be separated analytically from other levels (individuals, components of social systems, system organization) in socio-cultural systems, since its importance is similar to biological inheritance. In the course of differently triggered and more or less self-organized processes of social differentiation functionally specialized social subsystems appear. At the same time, the socially conditioned individualization of the members of societies is driven forward. These processes of social change are therefore accompanied by changes in the production of reality: a plurality of social realities arises. At the same time, older constructs of reality are disappearing or are generalized, together with knowledge generated in specific areas of society. To cope with the socially generated need for coordination (communication!) and stabilization of achieved differentiations, second order systems appear such as e.g. the system of justice, the science system or, of course, the media system. Such second-order systems are not only necessary to assure the functioning of complex societies but they contribute to produce realities which are constructed and not given.

Heinz von Foerster’s distinction between trivial and non-trivial machines is extended by identifying three types of non-trivial machine. These distinctions are used to weave together 19 propositions on cybernetics and social transformation. The propositions offer a foundation for research on knowledge processes and the technology of knowledge. This research is characterized by questions that von Foerster has referred to as ‘undecidable questions’: questions which only we can decide; and the propositions are stated in such a way as to emphasize that. It is suggested that everyone has the ability to participate in social transformation and that cybernetics points to an opportunity to do so in a particular way. Heinz von Foerster, through both his work and his persona, has made this perspective possible.

Key words: cybernetics, social transformation, knowledge processes, non-trivial machine, undecidable questions, eigenrelations, art, time, emotionality