AbstractIn the history of formal semantics, the successful joining of linguistic and philosophical work brought with it some difficult foundational questions concerning the nature of meaning and the nature of knowledge of language in the domain of semantics: questions in part about “what’s in the head” of a competent language-user. This chapter, part of a project on the history of formal semantics, revisits the central issues of Partee (1979) in a historical context, as a clash between two traditions, Fregean and Chomskyan, a clash that accompanied early work combining Montague’s semantics with Chomskyan syntax. Recent advances in philosophy of mind (from, e.g., Stalnaker and Burge) go a long way towards changing the framework of arguments about “psychological reality” and “competence”, challenging the suppositions on which the original dichotomy rested, thus largely defusing the tension.