Like any apparently novel approach to the basic epistemological problems of "knowledge," the constructivist ideas that have spread in the last 20 years continue to generate a host of negative as well as a few positive reactions. This document focuses on some aspects of Radical Constructivism, as distinct from "trivial" constructivism, and attempts to show that the major objections that have been raised against it are due to gross misinterpretation and turn out to be vacuous once the position is made a little clearer. Discussions include historical perspectives, key concepts of radical constructivism, perspectives on reality and knowledge, and learning as construction. A list of 29 references is included. (Author/CW)