Glasersfeld E. von (1974) Piaget and the radical constructivist epistemology. In: Smock C. D. & Glasersfeld E. von (eds.) Epistemology and education. Follow Through Publications, Athens GA: 1–24. https://cepa.info/1324
Excerpt: As we know well enough from our own experience, at that level of elaboration, the “permanence” or “universality” of our cognitive constructs tends to become precarious. But even if it did not, even if we could achieve perfect intersubjective agreement of structures, it still would not get us across the border of the black box, because all it would tell us with certainty is that we, collectively, have found one viable construction. Such a construction becomes no more “real,” in the ontological sense, if we share it – it would still be based solely on signals on our side of the construct we have called “experiential interface,” and on the particular way in which we have categorized, processed, and coordinated these signals as input to, or output from, the construct we have called “universe.”
In this seminal paper, Ernst von Glasersfeld introduced a new interpretation of Jean Piaget, which he called “radical constructivism.” He defined cognition as “a constitutive activity which, alone, is responsible for every type or kind of structure an organism comes to know” – hence “radical” (Glasersfeld 1974: 10). Amalgamating various strands of philosophical thought, he pushed for a change in how the terms knowledge and communication should be understood – a change of “drastic nature” that “involves the demolition of our everyday conception of reality,” (Glasersfeld 1974: 2) and that would, as von Glasersfeld claimed in various papers afterwards, affect the “fundamental presuppositions of the traditional theories of education” (Glasersfeld 1983: 41). (From Riegler A.