Ernst von Glasersfeld's presentation of the ideas, results, and problems of radical constructivism intertwines three strands: the depiction of his own intellectual biography, which convincingly illustrates his "coming of age as a constructivist"; the analysis of the works of prominent thinkers in the history of philosophy who have developed fundamental ideas upon which constructivist thought is based; and the demonstration of the viability of constructivist thinking in addressing central issues in philosophy, psychology, and education.