Publication 195

Purpose: My goals in this paper are to comment on some of the roles that Ernst von Glasersfeld played in our work in IRON (Interdisciplinary Research on Number) from circa 1975 up until the time of his death, and to relate certain events that revealed his character in very human terms. Method: Among my recollections of Ernst, I have chosen those that I felt would most adequately portray his impact on the field of mathematics education and his ethics in the field of human affairs. Findings: It has not often been said but, in his work in IRON, it was Ernst’s explicit intention to start a conceptual revolution in mathematics education and beyond. Other than serving as a revolutionary, Ernst also served as a mentor for many investigators in mathematics education, including myself. He excelled as a scientist as well an epistemologist, and his scientific work fueled his epistemological work. Ernst was a very ethical and wonderful human being who was dedicated to the betterment of humankind by means of his revolutionary ideas.

Key words: paradigm shift, constructivism, mathematics education, conceptual analysis