peer reviewedI will defend the claim that we need to differentiate between thinking and reasoning in order to make progress in understanding the intricate relation between language and mind. The distinction between thinking and reasoning will allow us to apply a structural equivalent of Ludwig Wittgenstein’s Private Language Argument to the domain of mind and language. This argumentative strategy enables us to show that and how a certain subcategory of cognitive processes, namely reasoning, is constitutively dependent on language. The final outcome and claim of this paper can be summarized as follows: We can think without language, but we cannot reason without language. While this still leaves several questions about the relation be...