Abstract

I argue that Abelard was the author of the first theory of mental language in the Middle Ages, devising a “language of thought” to provide the semantics for ordinary languages, based on the idea that thoughts have linguistic character. I examine Abelard’s semantic framework with special attention to his principle of compositionality (the meaning of a whole is a function of the meanings of the parts); the results are then applied to Abelard’s distinction between complete and incomplete expressions, as well as the distinction between sentences and the statements which the sentences are used to make. Abelard’s theory of mental language is shown to be subtle and sophisticated, the forerunner of the great theories of the fourteenth century.