1 Simon Kirchin s.t.kirchin@kent.ac.uk Draft: 30 th April 2015 (Don’t cite without permission – thanks) Reflections from Wolf and Wood: Incommensurability, Guidance, and the ‘Smoothing Over’ of Ethical Life 1. Introduction In OWM Derek Parfit argues that the best versions of Kantianism, Scanlonian contractualism, and rule consequentialism can be combined into a position - the Triple Theory - that shows us what sort of ethical principles we should adopt to guide our behaviour and moral judgement. These three theories are traditionally thought to be rivals, with deep differences. The prospect of their convergence is one of Parfit’s most exciting proposals in OWM. In this paper I think about the very idea of combining these three theories. I do so by looking at Parfit’s ambitions through the eyes of two of his commentators from volume II, namely Susan Wolf and Allen Wood. 1 This may seem an odd step in a volume devoted to Parfit’s work. But I do so because, in his interesting responses, Parfit doesn’t engage with what I find most arresting about what Wolf and Wood say. Their criticisms connect with the heart of the whole OWM project and part of my aim is to encourage Parfit to say something in his defence. Wolf suggests that the attempt to synthesize Kantianism, Scanlonian contractualism and rule consequentialism is unwise, mainly because these theories see different features of our lives as being ethically significant and because they cast many of the same moral features differently. Having highlighted particular parts of Wolf’s criticism, I extend her commentary by articulating the theoretical underpinning that Parfit seems to assume for his view. He assumes that normative ethical theories are good and decent only if they can provide clear, practical guidance, and in turn this requires an assumption that all values and things valued are commensurable. This has, in addition, connections with his metaethics in Part Six. I 1 Some of their criticisms are echoed in Kitcher (2012).