Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Constructivist Foundations is a four-monthly interdisciplinary peer-reviewed academic journal that focusses on constructivist approaches to science and philosophy, especially radical constructivism, enactive cognitive science, second order cybernetics, biology of cognition and the theory of autopoiesis systems, non-dualizing philosophy, among others. The journal publishes scholarly articles with empirical, formal or conceptual content, survey articles providing an extensive overview, target articles which are openly discussed in commentatories, opinions written by authorities in their field, and book reviews. The constructivist approaches covered in the journal question the Cartesian separation between objective world and subjective experience and demand the inclusion of the observer in scientific explanations. They reject representationalism and support the view that knowledge is a system-related cognitive process rather than a mapping of an objective world onto subjective cognitive structures.