Modularity, language, and the flexibility of thought

The present response elucidates, elaborates, and defends the main thesis advanced in the target article: namely, that natural-language sentences play a constitutive role in some human thought processes, and that they are responsible for some of the distinctive flexibility of human thinking, serving to integrate the outputs of a variety of conceptual modules. Section R1 clarifies and elaborates this main thesis, responding to a number of objections and misunderstandings. Section R2 considers three contrasting accounts of the mechanism of intermodular integration. Section R3 discusses objections to some of the empirical data supporting my main thesis. Section R4 criticizes some competing theories of the role of language in cognition. And section R5 considers some proposed supplementary cognitive roles that language might play.