The purpose of this book is to introduce a novel approach to social ontology. Like any other ontological investigation it concerns itself with the question of what kinds of entities we can legitimately commit ourselves to assert exist. The ontological stance taken here has traditionally been labelled ‘realist’: a stance usually defined by a commitment to the mindindependent existence of reality. In the case of social ontology, however, this definition must be qualified because most social entities, from small communities to large nation-states, would disappear altogether if human minds ceased to exist. In this sense social entities are clearly not mindindependent. Hence, a realist approach to social ontology must assert the autonomy of social entities from the conceptions we have of them. To say that social entities have a reality that is conception-independent is simply to assert that the theories, models and classifications we use to study them may be objectively wrong, that is, that they may fail to capture the real history and internal dynamics of those entities. There are, however, important cases in which the very models and classifications social scientists use affect the behaviour of the entities being studied. Political or medical classifications using categories like ‘female refugee’or ‘hyperactive child’, for example, may interact with the people being classified if they become aware of the fact that they are being so classified. In the first case, a woman fleeing terrible conditions in her home country may become aware of the criteria to classify ‘female refugees’ used by the country to which she wants to emigrate, and change her behaviour to fit that criteria. In this case, an ontological commitment to the referent of the term ‘female refugee’would be hard to maintain, since the very use of the term may be creating its own referents. On the other hand, accepting that the referents of some general terms may in fact be moving targets does not undermine social realism: to explain the case of the female refugee one has to invoke, in addition to her awareness of the meaning of the term ‘female refugee’, the objective existence of a whole set of institutional organizations (courts, immigration agencies, airports and seaports, detention centres), institutional norms and objects (laws, binding court decisions, passports) and institutional practices (confining, monitoring, interrogating), forming