Ernst von Glasersfeld

Ernst von Glasersfeld was an Austrian-born philosopher and psychologist who developed radical constructivism, a theory of knowing that holds that individuals actively construct their own understanding of the world from experience rather than passively receiving fixed external truths. Building on the work of Jean Piaget, von Glasersfeld argued that knowledge cannot be a direct copy of reality but is instead viable, meaning it functions successfully within an individual's experience. His writings, including Radical Constructivism: A Way of Knowing and Learning, strongly influenced constructivist approaches to teaching in mathematics and science education from the 1980s onward.