Recent years have seen a dramatic re-emergence of interest in ontology. From philosophy and social sciences to artificial intelligence and computer science, ontology is gaining interdisciplinary influence as a popular tool for applied research. focuses specifically on these developments within the social sciences. The contributions reveal that this revived interest in social ontology involves far more than an unquestioning acceptance or application of the concepts and methods of academic philosophers. Instead as ontology permeates so many new areas, social ontology itself is evolving in new and fascinating ways. This book engages with these new developments, pushing it forward with cutting-edge new material from leading authors in this area, from Roy Bhaskar to Margaret Archer. It also explicitly analyzes the relationship between the new ontological projects and the more traditional approaches.