A friend says intellectual Ernst von Glasersfeld, known for developing the theory of radical constructivism, has died. He was 93.
Josef Mitterer, a professor at the University of Klagenfurt in Austria, says von Glasersfeld -- who held U.S. and Irish citizenship -- died Friday of pancreatic cancer at his home in Leverett, Massachusetts.
Von Glasersfeld, who was born of Austrian parents in the German city of Munich in 1917, taught at the University of Georgia and was associated member of the Scientific Reasoning Research Institute at the University of Massachusetts Amherst.
Von Glasersfeld described radical constructivism as "an unconventional approach to the problems of knowledge and knowing."