Ich verstehe unter “Wirklichkeit” ein Netzwerk von Begriffen, die sich in der bisherigen Erfahrung des Erlebenden als angemessen, brauchbar, oder “viabel” erwiesen haben, und zwar dadurch, daß sie wiederholt zur erfolgreichen Überwindung von Hindernissen oder zur begrifflichen “Assimiliation” von Erfahrungskomplexen gedient haben.
Wege des Wissens. Konstruktivistische Erkundungen durch unser Denken. Hg. von Hans Rudi Fischer, 1997, p. 47.
Once knowing is no longer understood as the search for an iconic representation of ontological reality but, instead, as a search for fitting ways of behaving and thinking, the traditional problem disappears. Knowledge can now be seen as something which the organism builds up in the attempt to order the as such amorphous flow of experience by establishing repeatable experiences and relatively reliable relations between them. The possibilities of constructing such an order are determined and perpetually constrained by the preceding steps in the construction. That means that the “real” world manifests itself exclusively there where our constructions break down. But since we can describe and explain these breakdowns only in the very concepts that we have used to build the failing structures, this process can never yield a picture of a world that we could hold responsible for their failure.
An Introduction to Radical Constructivism, in: Paul Watzlawick (Hg.): The Invented Reality, 1984, p. 39.