Definitional equivalence and plural logic

Salvatore Florio, Stewart Shapiro, and Eric Snyder

Atomistic classical mereology and plural logic provide two alternative frameworks for the analysis of plurals in natural language. It is a matter of dispute which framework is preferable. From the formal point of view, however, the two frameworks can be shown to be definitionally equivalent. So they have the same coverage as each other: there is a range of data that they both capture correctly and a range of data that they both fail to capture or get wrong. We argue that the tie is broken when we consider a wider range of linguistic phenomena, such as mass nouns and group nouns. Mereology is more flexible than plural logic and is thus more easily adapted to account for these richer fragments of natural language.