 G.E. Moore famously attacks this argument, suggesting that “the fallacy in this step is so obvious, that is quite wonderful how Mill failed to see it” (Moore 1993: 118). ‘Desired’ does not bear the same relation to ‘desirable’ as ‘heard’ does to ‘audible’—for desirability is the property of being deserving or worthy of being desired, whereas audibility is property of being capable of being heard. Mill’s choice of framing the argument in this way is, admittedly, unfortunate, but the basic thrust of the argument is nevertheless strong, if understood in terms of its own aims.