 Moreover, as Hurka has developed the point, the “initial reviewers of Principia did not see it as altering Sidgwick’s ontology but emphasized its continuity with Sidgwick, while Moore himself said little about his non-natural property and even tried to limit his metaphysical claims, saying that though goodness is an object and therefore ‘is somehow’, it does not ‘exist’, and in particular does not exist in a ‘supersensible reality’ ” (Hurka 2014: 90). For his part, Sidgwick goes on to argue that the best going account of ultimate goodness is a hedonistic one, and that this is an informative, non-tautological claim, though also a more controversial one than many of the others that he defends. As Irwin and Richardson have insightfully argued, Sidgwick’s hedonistic commitments, and his criticisms of such views as T. H. Green’s, often reflected the (problematic) conviction that practical reason simply must be fully clear and determinate in its conclusions (Irwin 1992: 288–90; Richardson 1997). Without some such metric as the hedonistic one, Sidgwick argued, how can one virtue be compared to another? And can one really recommend making people more virtuous at the expense of their happiness? What if the virtuous life were conjoined to extreme pain, with no compensating good to anyone? But here again, Sidgwick’s arguments are not as perspicuous as they at first seem. Admittedly, as Shaver points out, “Sidgwick works out what it is reasonable to desire, and so attaches moral to natural properties, by the ordinary gamut of philosopher’s strategies—appeals to logical coherence, plausibility, and judgment after reflection.” (Shaver 1997: 270). Even so, as Rawls noted, “Sidgwick denies that pleasure is a measurable quality of feeling independent of its relation from volition. This is the view of some writers, he says, but one he cannot accept. He defines pleasure ‘as a feeling which, when experienced by intelligent beings, is at least apprehended as desirable or—in cases of comparison—preferable.’ It would seem that the view he here rejects is the one he relies upon later as the final criterion to introduce coherence among ends.” (Rawls [1971], 1999: 488). Sumner, in an important treatment, has also urged that Sidgwick and Mill, by contrast with Bentham,