Abstract: It has traditionally been thought that the substitution of co-referential terms succeeds in all but a few special linguistic contexts, such as belief reports. Philosophers have devoted considerable energy to attempting to understand these special contexts. This book discusses apparent cases of substitution failure in simple sentences: those that do not involve any such special contexts. It shows that existing theories — whether semantic or pragmatic — cannot accommodate these cases, and that certain central assumptions regarding the role of intuitions must be abandoned in order to deal with them. The book offers a new explanation of anti-substitution intuitions that builds on empirical data from psychology, and explores the methodological implications of this form of explanation.

Keywords: belief reports, co-referential terms, semantic, pragmatic, substitution failure