In ontology, realism and anti-realism may be taken as opposite attitudes towards entities of different kinds, so that one may turn out to be a realist with respect to certain entities, and an anti-realist with respect to others. In this book, the editors focus on this controversy concerning social entities in general and fictional entities in particular, the latter often being considered nowadays as kinds of social entities. More specifically, fictionalists (those who maintain that we only ma...