Despite this, his attempt to demonstrate the relevance of Peirce's semiotics in contemporary philosophical thought hinges on a balanced interplay between convincing arguments and documented research. This book insightfully unravels the necessity of overcoming the contemporary philosophical tendency to 'atomize issues' (xi), and there is reason to believe that Short's comprehensive study will set the agenda for interesting future developments in Peircean scholarship. Chiara Ambrosio University College London Walter Sinnott-Armstrong Moral Skepticisms. New York: Oxford University Press 2006. Pp. 288. US$48.00 (cloth ISBN-13: 978-0-195-18722-4). To the best of my knowledge, this is the first book entirely devoted to examining the different varieties of moral skepticism and to assessing the main replies to moral skeptical arguments. Sinnott-Armstrong's aim is to determine whether, how, and to what extent our moral beliefs can be justified. His discussion of these issues is remarkably clear, thorough, and solid. The book is divided into two parts. The first presents the basic concepts of moral epistemology and the arguments advanced by different forms of moral skepticism. It offers a characterization of moral epistemology (Chapter 1), and examines whether moral beliefs are truth-apt (Chapter 2), true (Chapter 3) and justified (Chapter 4). It introduces the notion of contrast classes (Chapter 5), and expounds Sinnott-Armstrong's own variety of moral skepticism, namely, 'classy moral Pyrrhonism' (Chapter 6). The second part is devoted to analyzing four ethical theories purporting to justify moral beliefs naturalism (Chapter 7), normativism (Chapter 8), intuitionism (Chapter 9), and coherentism (Chapter 10) as well as their responses to moral nihilism. Sinnott-Armstrong describes his own position as skeptical. However, it is not a form of ontological moral skepticism, which is probably the most common type of moral skepticism in contemporary philosophy. He maintains that the arguments against the existence of moral facts do not establish their conclusions; at most they require us to suspend judgment about the existence of such facts. Similarly, he holds that the most common and important arguments against moral nihilism are not conclusive, although he thinks that 303 they show some of our beliefs to be justified not absolutely, but in limited ways. Because he rejects that our moral beliefs are unqualifiedly justified, but accepts that they may be partially justified, Sinnott-Armstrong characterizes his outlook as a 'moderate moral skepticism'. How does he support this mitigated skepticism? The key lies in the notion of 'contrast class'. A contrast class is a set of propositions which are incompatible with each other, so that if one is justified in believing a proposition P out of a contrast class C, it is because one has grounds that rule out all the other propositions of C but not P. Now, a belief may be, at the same time, justified out of one contrast class, but not out of another. For it may be justified, e.g., out of a contrast class which includes all the alternatives which can be eliminated by using our usual epistemic standards, but not out of a contrast class which also includes extreme alternatives such as skeptical hypotheses, which are systematically uneliminable. The question that naturally arises is which contrast class is really relevant, i.e., which contrast class contains those alternatives that must be eliminated to be able to affirm that a given belief is epistemically justified without qualification. Sinnott-Armstrong maintains that this question is impossible to answer, so he suspends judgment about which contrast class, if any, is really relevant, even in a particular context. (This is why he describes himself as a meta-skeptic about real relevance, or as a 'classy Pynhonist' .) As a result, moral beliefs can be justified or unjustified, not absolutely, but solely relative to different contrast classes. Given that Sinnott-Armstrong suspends judgment about real relevance, it seems that his position is a sort of epistemic relativism about moral beliefs. Although several issues invite discussion, I will limit myself to two of them. First, I find surprising Sinnott-Armstrong's views that 'second-order beliefs about the epistemic status of moral beliefs cannot force us to give up the moral beliefs that we need to live well' (viii), and that the skeptical 'position about the epistemic status of moral beliefs need not trickle down and infect anyone's substantive moral beliefs or actions' (14). This is a clear case of what has been called 'insulation', which takes place when (some of) our ordinary beliefs are deemed to be immune from the conclusions of philosophical arguments, and hence from philosophical skepticism. Even if insulation is a common phenomenon in contemporary philosophy, I confess my difficulty in comprehending how, if we suspend judgment about the epistemic credentials of our moral beliefs, we can still affirm that we are epistemically justified in holding a number of them. I understand that, in such a situation, holding moral beliefs may have some kind of practical justification, but this of course does not confer any epistemic justification on them. Second, readers familiar with Sextus Empiricus might wonder whether Sinnott-Armstrong's outlook may be legitimately labeled 'Pyrrhonian'. It is clear that the ancient Pyrrhonist would agree both with the idea that, as things stand, we can rule out neither moral nihilism nor moral realism, and with refraining from affirming that any one contrast class is really relevant. On the other hand, he would not consider his skeptical stance to be fully compatible with Sinnott-Armstrong's moderate moral skepticism for at least 304 three reasons. First, he would reject the idea that our substantive moral beliefs are insulated and immune from philosophical reflection. Second, given that Sinnott-Armstrong's moral skepticism does not prevent him from affirming that his 'positive moral beliefs are true and correspond to moral facts' (58), the Pyrrhonist would consider his position to be 'dogmatic', because it makes assertions about matters of objective fact, even if these epistemic claims are only relativized. Finally, I doubt the Pyrrhonist would accept that our moral beliefs may be justified out of a limited contrast class. Indeed, he would probably argue that, even if one restricts oneself to limited contrast classes, it does not seem possible to choose among the competing alternatives constituting the class because they appear equally persuasive. These differences between Sinnott-Armstrong's position and Pyrrhonism may not represent a pressing problem for him, since he points out that he does not care whether his 'position gets labeled "skepticism"', because the 'name does not matter to any issue of importance'. Rather, what matters is both what it is possible to accomplish 'when we try to justify our moral beliefs', and 'which debates in epistemology make sense' (251; cf. 106n27). These reservations, however, concern not merely historical accuracy (which, to be sure, is not irrelevant, because Sinnott-Armstrong calls his position 'skepticism' to 'reveal its connections to the Pyrrhonian tradition' (251]). Rather, they are motivated primarily by the fact that the Pyrrhonian stance and Pyrrhonian arguments have been playing a key part in current epistemological discussions for some time now, so that it is crucial to get an accurate picture of Pyrrhonism when dealing with issues of knowledge and justification. Given its philosophical rigor and insight and the import of the issues it deals with, I highly recommend this book not solely to those interested in moral epistemology but to anyone concerned with epistemology in general. Diego E. Machuca Consejo Nacional de Investigaciones Cientificas y Tecnicas