The thesis of methodological individualism in social science is commonly divided into two different claims—explanatory individualism and ontological individualism. Ontological individualism is the thesis that facts about individuals exhaustively determine social facts. Initially taken to be a claim about the identity of groups with sets of individuals or their properties, ontological individualism has more recently been understood as a global supervenience claim. While explanatory individualism has remained controversial, ontological individualism thus understood is almost universally accepted. In this paper I argue (...) that ontological individualism is false. Only if the thesis is weakened to the point that it is equivalent to physicalism can it be true, but then it fails to be a thesis about the determination of social facts by facts about individual persons. Even when individualistic facts are expanded to include people’s local environments and practices, I shall argue, those still underdetermine the social facts that obtain. If true, this has implications for explanation as well as ontology. I first consider arguments against the local supervenience of social facts on facts about individuals, correcting some flaws in existing arguments and affirming that local supervenience fails for a broad set of social properties. I subsequently apply a similar approach to defeat a particularly weak form of global supervenience, and consider potential responses. Finally, I explore why it is that people have taken ontological individualism to be true. (shrink)

Social ontology is the study of the nature and properties of the social world. It is concerned with analyzing the various entities in the world that arise from social interaction. -/- A prominent topic in social ontology is the analysis of social groups. Do social groups exist at all? If so, what sorts of entities are they, and how are they created? Is a social group distinct from the collection of people who are its members, and if so, how is (...) it different? What sorts of properties do social groups have? Can they have beliefs or intentions? Can they perform actions? And if so, what does it take for a group to believe, intend, or act? -/- Other entities investigated in social ontology include money, corporations, institutions, property, social classes, races, genders, artifacts, artworks, language, and law. It is difficult to delineate a precise scope for the field (see section 2.1). In general, though, the entities explored in social ontology largely overlap with those that social scientists work on. A good deal of the work in social ontology takes place within the social sciences (see sections 5.1–5.8). -/- Social ontology also addresses more basic questions about the nature of the social world. One set of questions pertains to the constituents, or building blocks, of social things in general. For instance, some theories argue that social entities are built out of the psychological states of individual people, while others argue that they are built out of actions, and yet others that they are built out of practices. Still other theories deny that a distinction can even be made between the social and the non-social. -/- A different set of questions pertains to how social categories are constructed or set up. Are social categories and kinds produced by our attitudes? By our language? Are they produced by causal patterns? And is there just one way social categories are set up, or are there many varieties of social construction? -/- The term ‘social ontology’ has only come into wide currency in recent years, but the nature of the social has been a topic of inquiry since ancient Greece. As a whole, the field can be understood as a branch of metaphysics, the general inquiry into the nature of entities. (shrink)