Carruthers, PeterThis chapter argues that our language faculty can both be a peripheral module of the mind and be crucially implicated in a variety of central cognitive functions, including conscious propositional thinking and reasoning. I also sketch arguments for the view that natural language representations (e.g. of Chomsky’s Logical Form, or LF) might serve as a lingua franca for interactions (both conscious and non-conscious) between a number of quasi-modular central systems. The ideas presented are compared and contrasted with the evolutionary proposals made by Derek Bickerton (1990, 1995), who has also argued for the involvement of language in thought. Finally, I propose that it was the evolution of a mechanism responsible for pretend play, circa 40,000 years ago, which led to the explosion of creative culture visible in the fossil record from that time onwards.enlanguage facultymodulesmodularitymindcognitioncognitive functionpropositional thinkingreasoningnatural language representationsLogical Formquasi-modular central systemsevolutionBook chapter