Constructivist Foundations is an international triannual peer-reviewed academic journal that focuses on constructivist approaches to science and philosophy, including radical constructivism, enactive cognitive science, second-order cybernetics, biology of cognition and the theory of autopoietic systems, and non-dualizing philosophy[clarification needed]. It was established in 2005 and the editor-in-chief is Alexander Riegler (Free University of Brussels).