 The most widely discussed attempt at a straight solution to the sceptical challenge is reductive dispositionalism. According to a simple version of reductive dispositionalism, the fact that Jones has the concept of addition rather than of quaddition is to be identified with (or is constituted by) his disposition to produce the result of adding (and not quadding) the numbers x and y in response to arithmetical queries of the form ‘\(x + y = \ques\)’, and the fact that he means cat by ‘cat’ is to be identified with (or is constituted by) his disposition to apply ‘cat’ to cats. (See Horwich 1998, 2010, 2012 for a systematic development of dispositionalism; an answer to Kripke’s challenge is articulated in Horwich 2015.) 