Abstract
In the study of expertise, few debates come as big as that between constructivists and realists. This chapter discusses the signal debate between realists and constructivists about expertise. It sets out a view that includes aspects of both the constructivist and realist position to show that insights from what is often considered to be rival camps can be incorporated in a position that does justice to both. The chapter argues that, while expertise is real, there are two distinct social dimensions to the concept of expertise. It attempts to demonstrate two distinct ways in which expertise has a social dimension. First, the chapter develops an account according to which 'is an expert' is a triadic predicate. Second, it considers the fact that attributions of expertise are often done by institutions, i.e. by medical boards certifying doctors, etc. Both dimensions can be acknowledged without undermining the basic case for realism about expertise.