Among the passages which are suggestive of a philosophy of language in Kant’s writings are his remarks and arguments on appropriate terminology for philosophical concepts. I ask what it is for Kant that makes some words more suitable than others. I reconstruct the arguments from the Inquiry concerning the distinctness of the principles of natural theology and morality (1764) and the Critique of Pure Reason (1781/1787) that defend that there is no such thing as a proper, real definition for philosophical (...) concepts (only nominal definition and exposition); in addition, philosophical concepts are only represented by terms in abstracto, not in concreto. On these grounds, in the Inquiry, Kant sustains that the reference of a term to a philosophical concept is ultimately sanctioned by the term’s ‘linguistic usage’ (Redegebrauch). I argue that this is the basis for Kant’s criterion in the Critique of Pure Reason of employing traditional terminology, words from ordinary language, or even words from extinct languages, to refer to philosophical concepts, and for his rejection of coining new terms – even for distinctly new philosophical thoughts. (shrink)