The social sciences study knowing subjects and their interactions. A "cognitive turn", based on cognitive science, has the potential to enrich these sciences considerably. Cognitive economics belongs within this movement of the social sciences. It aims to take into account the cognitive processes of individuals in economic theory, both on the level of the agent and on the level of their dynamic interactions and the resulting collective phenomena. This book is a result of a three-year experiment in interdisciplinary cooperation in cognitive economics. It has the advantage of reflecting joint, long-term work between economists, specialists in cognitive science, physicists, mathematicians and computer scientists. The main aim of the book is to enable any researcher interested in cognitive economics, whatever his or her original speciality, to grasp essential landmarks in this emerging field. Part I of the book provides disciplinary bases, Part II is focused on advanced research.