Folke Tersman

Some philosophers question whether higher-order evidence can support the radical skeptical conclusions that others take it to generate. Since disagreement is usually classified as being a type of higher-order evidence, these worries have in turn also been taken to cast doubts on skeptical arguments that appeal to disagreement. This chapter explores the idea that disagreement can make a belief unjustified by serving as an "undercutting defeater"; i.e., as a consideration which severs the link between the grounds we have for the belief and its truth. It is shown that this idea allows advocates of skeptical arguments from disagreement to respond to the worries about the significance of higher-order evidence.

This chapter argues that establishing that moral beliefs are safe (i.e. could not easily have been false) and sensitive (i.e. would have been different had the target facts been different) is not enough to ward off the sceptical challenge occasioned by a debunking evolutionary explanation of those beliefs; explaining the reliability of moral beliefs requires more than this. The chapter also addresses the issue of what exactly is being conceded by the sceptic for the purpose of an evolutionary debunking argument, if such arguments are to be dialectically interesting. It is argued that there is a genuine question-begging concern in the dialectic here.

How is someone who seeks a reflective equilibrium to respond upon learning that others disagree with her? Regrettably, not much attention has been devoted to that question despite the extensive general discussion about the epistemic significance of disagreement that has taken place in recent years. This paper helps fill the lacuna by exploring possible connections between the relevant bodies of literature. More specifically, I claim that how users of the method of reflective equilibrium should respond to disagreement is crucial to the assessment of the method. According to a common objection, it is flawed because it may lead competent and rational inquirers to arrive at widely divergent and inconsistent equilibria. What I argue is that defensible assumptions about the significance of disagreement permit an advocate of the method to resist that objection.

Facts about moral disagreement and human evolution have both been said to exclude the possibility of moral knowledge, but the question of how these challenges interact has largely gone unaddressed. The paper aims to present and defend a novel version of the evolutionary “debunking” argument for moral skepticism that appeals to both types of considerations. This argument has several advantages compared to more familiar versions. The standard debunking strategy is to argue that evolutionary accounts of moral beliefs generate skeptical implications because they attribute those beliefs to factors that are unrelated to their truth. That strategy is vulnerable to “third-factor” responses, which invoke first-order moral claims to challenge the assumption that Darwinian factors and the moral truths are really unrelated in that way. In contrast, our version is immune to those responses, as it does not proceed via assumptions about how Darwinian factors relate to the moral facts. Instead, it focuses on what evolutionary accounts of moral beliefs have to say about the fact that people often reach divergent moral beliefs. The argument thereby illustrates how the debunking strategy can join forces with the argument from moral disagreement. The combination of those strategies presents, we think, a challenge that is more formidable than when they are considered separately.

A long-standing family of worries about moral realism focuses on its implications for moral epistemology. The underlying concern is that if moral truths have the nature that realists believe, it is hard to see how we could know what they are. This objection may be called the “argument from skepticism” against moral realism. Realists have primarily responded to this argument by presenting accounts of how we could acquire knowledge of moral truths that are consistent with realist assumptions about their nature. Less time has been spent, however, on the question of why it would be a problem for moral realism if it leads to skepticism in the first place, and on the related question of which skeptical conclusions it would be problematic for realists to simply accept. This paper considers several answers to these questions, thereby distinguishing a number of versions of the argument from skepticism, and discusses their prospects.

A common anti-realist strategy is to argue that moral realism (or at least the non-naturalist form of it) should be abandoned because it cannot adequately make room for moral knowledge and justified moral belief, for example in view of an evolutionary account of the origins of moral beliefs or of the existence of radical moral disagreement. Why is that (alleged) fact supposed to undermine realism? I examine and discuss three possible answers to this question. According to the answer that I think holds most promise, it undermines realism because it renders realism “epistemically incoherent” (in a sense explicated in the paper), and a central aim of the paper is to elaborate and defend that suggestion against certain objections. I end by briefly commenting on the more general significance of the discussion, by considering some other areas (epistemology and vagueness) where similar questions might be raised.

Moral disagreement is sometimes thought to pose problems for moral realism because it shows that we cannot achieve knowledge of the moral facts the realists posit. In particular, it is "fundamental" moral disagreement—that is, disagreement that is not due to distorting factors such as ignorance of relevant nonmoral facts, bad reasoning skills, or the like—that is supposed to generate skeptical implications. In this paper, we show that this version of the disagreement challenge is flawed as it stands. The reason is that the epistemic assumptions it requires are incompatible with the possibility of fundamental disagreement. However, we also present an alternative reconstruction of the challenge that avoids the problem. The challenge we present crucially invokes the principle that knowledge requires "adherence". While that requirement is usually not discussed in this context, we argue that it provides a promising explanation of why disagreement sometimes leads to skepticism.

The idea of reflective equilibrium remains the most popular approach to questions about method in ethics, despite the masses of criticism it has been faced with over the years. Is this due to the availability of compelling responses to the criticisms or rather to factors that are independent of its reasonableness? The aim of this paper is to provide support for the first answer. I particularly focus on the recent discussion. Some recent objections are related to general arguments against the possibility of moral knowledge, such as so-called “evolutionary debunking arguments.” I argue that nothing that has come to light in that debate, or in the recent discussion about IRE more generally, decisively strengthens the case against it. If anything, the recent developments show that IRE deserves its present status.

The Benacerraf challenge is a well-known objection to Platonism in mathematics. Its proponent argues that, if mathematical entities are, as Platonists claim, mind-independent, causally inert, and existent beyond space and time, then we are led to a skeptical stance according to which it is not possible to explain how it is that we have cognitive access to the mathematical realm or how it is that our mathematical beliefs are reliable. It has been argued that a similar objection could be leveled against those forms of moral realism that fall under what in Section 2 was called “robust moral realism.” In “Moral Skepticism and the Benacerraf Challenge,” Folke Tersman considers whether, unlike the argument from the best explanation, the argument from disagreement, and the argument from evolution, the moral version of the Benacerraf challenge can undermine moral knowledge without appealing to empirical claims that moral realists deem controversial. His verdict is negative: to successfully counter certain responses to the moral version of the challenge, its proponent needs to have recourse to empirical considerations taken from some of the above arguments

A recent study of moral intuitions, performed by Joshua Greene and a group of researchers at Princeton University, has recently received a lot of attention. Greene and his collaborators designed a set of experiments in which subjects were undergoing brain scanning as they were asked to respond to various practical dilemmas. They found that contemplation of some of these cases (cases where the subjects had to imagine that they must use some direct form of violence) elicited greater activity in certain areas of the brain associated with emotions compared with the other cases. It has been argued (e.g., by Peter Singer) that these results undermine the reliability of our moral intuitions, and therefore provide an objection to methods of moral reasoning that presuppose that they carry an evidential weight (such as the idea of reflective equilibrium). I distinguish between two ways in which Greene's findings lend support for a sceptical attitude towards intuitions. I argue that, given the first version of the challenge, the method of reflective equilibrium can easily accommodate the findings. As for the second version of the challenge, I argue that it does not so much pose a threat specifically to the method of reflective equilibrium but to the idea that moral claims can be justified through rational argumentation in general.

Some think that recent empirical research has shown that peoples' moral intuitions vary in a way that is hard to reconcile with the supposition that they are even modestly reliable. This is in turn supposed to generate skeptical conclusions regarding the claims and theories advanced by ethicists because of the crucial role intuitions have in the arguments offered in support of those claims. I begin by trying to articulate the most compelling version of this challenge. On that version, the main problem is the absence of a believable positive account of the reliability of the intuitions . I then consider the response to this challenge that, in my view, holds most promise. It differs from others by invoking substantive moral assumptions. Such a strategy may appear problematically circular, in that the justification of those assumptions seems to presuppose the very thesis that is challenged . However, although I think that objection can be met, I argue that there are other problems with the strategy. On the basis of a set of conditions that a successful defense of the pertinent kind plausibly must satisfy, I argue that the prospects of developing such an account are bleak

Crispin Wright holds that moral realism is implausible since it is not a priori that every moral disagreement involves cognitive shortcomings. I develop two responses to this argument. First, a realist may argue that it holds for at least one of the parties to any disagreement that he holds false background beliefs (moral or otherwise) or that his verdict to the disputed judgment fails to cohere with his system. Second, he may argue that if none of the verdicts involves shortcomings, the appropriate conclusion is that the disagreement is not genuine, since we must otherwise attribute an inexplicable error

A traditional objection to coherentism is that there may be incompatible though equally coherent sets of beliefs. The purpose of the paper is to assess this objection. It is argued that the better a belief "p" coheres with the system of a person, the less likely it is that the negation of the belief coheres equally well with someone else's system, or even that there is someone else who believes the negation of "p". The arguments are based on two plausible assumptions about coherence, and some more controversial assumptions concerning meaning and interpretation