This book focuses on the formation of human social consciousness and develops a naturalist approach to social normativity. Beginning from Marx's uncompleted concept of social consciousness, the book retrospects the studies about collective intentionality in the area of philosophy of mind and social ontology. Specifically, a reinterpretation of social consciousness with respect to collective intentionality can offer us a new, naturalistic approach to the social formation and normativity. According to the naturalistic approach, we can discern the inner structure of social consciousness as a systematic pattern of Intentionality. Social consciousness involves three levels of development: subjective, objective and absolute. With this new pattern of social consciousness, the "naturalism" of the young Karl Marx can be revived. And by grasping the most essential ability of human Intentionality as the source of social formation, it also makes an interdisciplinary study of social philosophyand philosophy of mind possible.