Knowledge: making sense of experience - EvG 1990

In 1990 Ernst von Glasersfeld wrote:

• If the view is adopted that “knowledge” is the conceptual means to make sense of experience, rather than a “representation” of something that is supposed to lie beyond it, this shift of perspective brings with it an important corollary: the concepts and relations in terms of which we perceive and conceive the experiential world we live in are necessarily generated by ourselves. In this sense it is we who are responsible for the world we are experiencing.
• As I have reiterated many times, radical constructivism does not suggest that we can construct anything we like, but it does claim that within the constraints that limit our construction there is room for an infinity of alternatives. 
• It therefore does not seem untimely to suggest a theory of knowing that draws attention to the knower’s responsibility for what the knower constructs.
• An exposition of constructivism: Why some like it radical . In: R. B. Davis, C. A. Maher & N. Noddings (ed.) Monographs of the J. for Research in Mathematics Education, #4. Reston, VA: National Council of Teachers of Mathematics, pp. 19–29.