There is renewed research and attention to race in epidemiology and medicine, partly owing to developments in population genetics. Yet race is a contested category and poses philosophical questions about the reality of racial categories as well as the ethical and social-political implications of using them. For instance, is race a social construction; and if so, how do racial categories line up with the world? Perhaps more pressingly, should we be using racial categories in epidemiology and medicine in the first place? Today’s consultation is with philosopher Sean Valles, Associate Professor at Michigan State University.