This paper critically examines coincidence arguments and evolutionary debunking arguments against non-naturalist realism in metaethics. It advances a version of these arguments that goes roughly like this: Given a non-naturalist, realist metaethic, it would be cosmically coincidental if our first order normative beliefs were true. This coincidence undermines any prima facie justification enjoyed by those beliefs.

It is often claimed that irreducibly normative truths would have unacceptable metaphysical implications, and are incompatible with a scientific view of the world. The book argues, on the basis of a general account of the relevance of ontological questions, that this claim is mistaken. It is also a mistake to think that interpreting normative judgments as beliefs would make it impossible to explain their connection with action. An agent’s acceptance of a normative judgment can explain that agent’s subsequent action because (...) it is part of being a rational agent that such an agent’s beliefs about reasons normally, but not invariably, make a difference to the agent’s subsequent behavior. Because facts about reasons are not entities existing apart from us, there is no epistemological problem of how we can “be in touch with” such facts. There are serious worries about normative knowledge, but the problems involved are internal to the normative domain itself. The best solution to these problems would be an overall account of the domain of reasons in normative terms, supported by an argument from reflective equilibrium. But no existing account, constructivist, or based on desires or on an idea of rationality, is plausible, and no alternative is likely to succeed. Conclusions about reasons for action must rest on more piecemeal applications of the method of reflective equilibrium. (shrink)

All contentious moral issues--from gay marriage to abortion and affirmative action--raise difficult questions about the justification of moral beliefs. How can we be justified in holding on to our own moral beliefs while recognizing that other intelligent people feel quite differently and that many moral beliefs are distorted by self-interest and by corrupt cultures? Even when almost everyone agrees--e.g. that experimental surgery without consent is immoral--can we know that such beliefs are true? If so, how? These profound questions lead to (...) fundamental issues about the nature of morality, language, metaphysics, justification, and knowledge. They also have tremendous practical importance in handling controversial moral questions in health care ethics, politics, law, and education. Sinnott-Armstrong here provides an extensive overview of these difficult subjects, looking at a wide variety of questions, including: Are any moral beliefs true? Are any justified? What is justified belief? The second half of the book explores various moral theories that have grappled with these issues, such as naturalism, normativism, intuitionism, and coherentism, all of which are attempts to answer moral skepticism. Sinnott-Armstrong argues that all these approaches fail to rule out moral nihilism--the view that nothing is really morally wrong or right, bad or good. Then he develops his own novel theory,--"moderate Pyrrhonian moral skepticism"--which concludes that some moral beliefs can be justified out of a modest contrast class but no moral beliefs can be justified out of an extreme contrast class. While explaining this original position and criticizing alternatives, Sinnott-Armstrong provides a wide-ranging survey of the epistemology of moral beliefs. (shrink)

A plurality of approaches to foundational aspects of mathematics is a fact of life. Two loci of this are discussed here, the classicism/constructivism controversy over standards of proof, and the plurality of universes of discourse for mathematics arising in set theory and in category theory, whose problematic relationship is discussed. The first case illustrates the hypothesis that a sufficiently rich subject matter may require a multiplicity of approaches. The second case, while in some respects special to mathematics, raises issues of (...) ontological multiplicity and relativity encountered in the natural sciences as well. (shrink)