Problems For Sinnott-Armstrong's Moral Contrastivism

In his recent book 'Moral Skepticisms' Walter Sinnott-Armstrong argues in great detail for contrastivism with respect to justified moral belief and moral knowledge. In this paper I raise three questions concerning this view. First, how would Sinnott-Armstrong account for constraints on admissible contrast classes? Second, how would he deal with notorious problems concerning relevant reference classes? And, finally, how can he account for basic features of moral agency? It turns out that the last problem is the most serious one for his account. There is a lot to think and talk about in Walter Sinnott-Armstrong’s brilliant and original book. I would like to raise three questions here: whether there are constraints on admissible contrast classes (I), whether contrastivism can accommodate a certain indeterminacy of relevant reference classes (II), and how contrastivism can account for 1 This article has been published in The Philosophical Quarterly 58, 2008, 463-470. The definitive version is available at http://onlinelibrary.wiley.com/doi/10.1111/j.14679213.2008.548.x/abstract. 2 See W. Sinnott-Armstrong, Moral Skepticisms (Oxford: Oxford University Press, 2006) and W. Sinnott-Armstrong, 'Moderate Classy Pyrrhonian Moral Scepticism', Philosophical Quarterly, this issue; see also W. Sinnott-Armstrong, 'Classy Pyrrhonism', in W. Sinnott-Armstrong (ed), Pyrrhonian Skepticism (Oxford: Oxford University Press 2004), pp. 188-207. W. SinnottArmstrong, 'Moral Skepticism and Justification', in W. Sinnott-Armstrong and M. Timmons (eds), Moral Knowledge? New Readings in Moral Epistemology (Oxford: Oxford University Press 1996), pp. 3-28 seems closer to contextualism than his most recent position. W. SinnottArmstrong, 'What's in a Contrast Class?', Analysis, 62 (2002), pp. 75-84 responds to challenges in A. Bird, 'Scepticism and Contrast Classes', Analysis 61 (2001), pp. 97-107.