Context: Few professional philosophers have addressed in any detail radical constructivism, but have focused instead on the related assumptions and limitations of postmodern epistemology, various anti-realisms, and subjective relativism. Problem: In an attempt to supply a philosophical answer to the guest editors’ question, “Why isn’t everyone a radical constructivist?” I address the realist (hence non-radical) implications of the theory’s invocation of “others” as an invariable, observer-independent, “external” constraint. Results: I argue that constructivists cannot consistently defend a radically subjectivist theory of knowing while remaining entirely agnostic about the nature and existence of the larger world (including independent others). That is, any non-solipsistic account of human experience must explicitly acknowledge its extra-subjective, ontological dimension. Implications: It follows that no pedagogical, social, philosophical, or commonsensical insight associated with so-called “trivial” or “social” constructivism survives or receives any support from the move to radical constructivism.

Key words: Ernst von Glasersfeld, solipsism, fictional posits, ontological agnosticism, others, subjects, observer-independence

Based primarily on the belief that it is man who constructs reality, a trend has grown in recent years to regard cybernetics as superseding the scientific methodology. Shows the untenability of this belief, its reliance on imprecise language, in particular on the ambiguous term “system,” and reiterates that sound cybernetics is just a part of the scientific tradition, firmly rooted in two Objectivity Axioms. The constructivist trend has drawn attention away from serious and difficult problems, and put the focus on the superficial and the trivial. Offers some suggestions as to how the cybernetical movement can regain contact with the advancing frontiers of science.

The central question in this paper is: Who (or what) constructs anticipations? I challenge the (tacit) assumption of Rosen’s standard definition of anticipatory systems according to which the cognitive system actively constructs a predictive model based on which it carries out anticipations. My arguments show that so-called implicit anticipatory systems are at the root of any other form of anticipatory systems as the nature of the “decision maker” in the latter cannot be a conscious one.

Key words: anticipation, radical constructivism, superstition, consciousness, readiness potential, Rosen, Libet

Radical Constructivism and Constructionism. Both radical constructivism and constructionism are naturalized approaches to epistemology. They try to fertilize results from biology and psychology for epistemological aims. They both refuse epistemological realism as unsustainable metaphysics. This raises the problem of the range of the naturalistic approach to epistemology. Constructivism, in both forms, turns out to be untenable because it runs in an aporia: it must borrow from realism either, or it must qualify its own position as a metaphysical one. But therewith, constructivism would be blamed to be metaphysical itself.

Key words: Constructivism, naturalism, epistemology, realism, idealism.