As the eleventh volume in the New Directions in Cognitive Science series (formerly the Vancouver Studies in Cognitive Science series), this work promises superb scholarship and interdisciplinary appeal. It addresses three areas of current and varied interest: common sense, reasoning, andrationality. While common sense and rationality often have been viewed as two distinct features in a unified cognitive map, this volume offers novel, even paradoxical, views of the relationship. Comprised of outstanding essays from distinguished philosophers, it considers what constitutes humanrationality, behavior, and intelligence covering diverse areas of philosophy, psychology, cognitive science, and computer science. Indeed, it is at the forefront of cognitive research and promises to be of unprecedented influence across numerous disciplines.