he sky, afterimages and dreams and for neglecting the role of color vision in surface segmentation. Neurophysiological subjectivism (the view that colors are in the head) is criticized for failing to recognize that colors belong to a shared biological and cultural world. A circular definition of color is adopted. It is argued that this circularity does not prevent color from exhibiting universals that can be studied by cognitive science. The discussion of color serves as a springboard for the introduction of the enactive approach. The enactive approach is presented as a middle way between the extremes of objectivism and (neurophysiological) subjectivism. Self-organization as viable, structural coupling between the cognitive system and the world (with appropriate perception/action loops) forms the kernel of the enactive program. The second major theme in the book is the nature of the self. A big departure is taken from all forms of materialism. A fundamental circularity is introduced be