The question, ‘Is cognition linguistic?' divides recent cognitive theories into two antagonistic groups. Sententialists claim that we think in some language, while advocates of non linguistic views of cognition deny this claim. The Introspective Argument for Sententialism is one of the most appealing arguments for sententialism. In substance, it claims that the introspective fact of inner speech provides strong evidence that our thoughts are linguistic. This article challenges this argument. I claim that the Introspective Argument for Sententialism confuses the content (...) of our thoughts with their vehicles: while sententialism is a thesis about the vehicles of our thoughts, inner speech sentences are the content of auditory or articulatory images. The rebuttal of the introspective argument for sententialism is shown to have a general significance in cognitive science: Introspection does not tell us how we think. (shrink)