 To possess a concept, it is sometimes suggested, is to have the capacity to use the concept in various propositional attitudes. Since it is essential to the propositional attitudes that they stand in certain rational interconnections with one another, it is argued, this essential normativity transfers to concepts and contents. Possessing a concept, grasping it, incurs a commitment to use the concept “in keeping with its content”, in the various propositional attitudes. If the speaker fails to do so, she has misused the concept in question (Millar 2004; McDowell &amp; Pettit 1986; Gibbard 2012: chapter 6).