Social ontology is the study of the nature and basic structure of social reality. It is a rapidly growing field at the intersection of philosophy and social science that has the potential to greatly assist social researchers of all kinds. One of the longest running projects in social ontology has developed over the better part of the last four decades through the work of Tony Lawson and the Cambridge Social Ontology Group. Cambridge social ontology has its origins in an assessment that the widespread explanatory failure of modern mainstream economics, as well as in the social sciences more generally, is due to sustained ontological neglect and the resulting use of research methods that are inappropriate, given the nature of social material. The Cambridge project’s aim has been to rectify this neglect through conducting explicit and sustained inquiry into the nature of social material with a view to elaborating an explanatorily powerful conception of social ontology. The result is social positioning theory. This book is an introduction to the key features of social positioning theory, provides context as to the theory’s development and illustrates how social positioning theory can clarify the natures of phenomena such as gender and the corporation. Cambridge Social Ontology is for social scientists, philosophers and all readers interested in gaining a better understanding of the nature of social phenomena.