Donald Davidson’s 1970 Locke Lectures appear in print for the first time in this volume, accompanied by an introduction highlighting their significance as a snapshot of his evolving views in the philosophy of language and describing their relationship to the work he published during his lifetime. The lectures comprise an invaluable historical document that illuminates how Davidson was thinking about the theory of meaning, the role of a truth theory therein, the ontological commitments of a truth theory, the notion of logical form, and so on, at a pivotal moment in the development of his thought. Unlike Davidson’s previously published work, they are written so as to be presented to an audience as a fully organized and coherent exposition of his program in the philosophy of language. Had these lectures been widely available in the years following 1970, the reception of Davidson’s work, especially in the philosophy of language, might have been very different. Given the systematic nature of the presentation of Davidson’s semantic program in these lectures, it is hoped that they will be of use to those encountering his thought for the first time.