 What are the problems with this “Millian argument”? The first problem, of course, is that (P) is not valid. While from the fact that x is heard, it follows that x is audible, it does not follow from that fact that x is desired that x is desirable in the sense necessary for the argument. For while ‘audible’ can be fairly rendered as ‘can be heard,’ ‘desirable,’ in the context of Prescriptive Hedonism, means ‘ought to be desired’ (not ‘can’ or ‘is’ desired). Thus, while it follows that: