This book offers a significant reconceptualization of the person system in natural language. The authors, leading scholars in syntax and its interfaces, propose that person features do not have inherent content but are used to navigate a “person space” at the heart of every pronominal expression. They map the journey of person features in grammar, from semantics through syntax to the system of morphological realization. Such an in-depth cross-modular study allows the development of a theory in which assumptions made about the behavior of a given feature in one module bear on possible assumptions about its behavior in other modules. The authors' new theory of person, built on a sparse set of two privative person features, delivers a typologically adequate inventory of persons; captures the semantics of personal pronouns, impersonal pronouns, and R-expressions; accounts for aspects of their syntactic behavior; and explains patterns of person-related syncretism in the realization of pronouns and inflectional endings. The authors discuss numerous observations from the literature, defend a number of theoretical choices that are either new or not generally accepted, and present novel empirical findings regarding phenomena as different as honorifics, number marking, and unagreement.