My aim in this paper is to develop and defend a novel answer to a question that has recently generated a considerable amount of controversy. The question concerns the normative significance of peer disagreement. Suppose that you and I have been exposed to the same evidence and arguments that bear on some proposition: there is no relevant consideration which is available to you but not to me, or vice versa. For the sake of concreteness, we might picture.

Discovering someone disagrees with you is a common occurrence. The question of epistemic significance of disagreement concerns how discovering that another disagrees with you affects the rationality of your beliefs on that topic. This book examines the answers that have been proposed to this question, and presents and defends its own answer.

In this paper, I explain a challenge to the Equal Weight View coming from the psychology of group inquiry, and evaluate its merits. I argue that while the evidence from the psychology of group inquiry does not give us a reason to reject the Equal Weight View, it does require making some clarifications regarding what the view does and does not entail, as well as a revisiting the ethics of belief.

Conciliatory views of disagreement maintain that discovering a particular type of disagreement requires that one make doxastic conciliation. In this paper I give a more formal characterization of such a view. After explaining and motivating this view as the correct view regarding the epistemic significance of disagreement, I proceed to defend it from several objections concerning higher-order evidence (evidence about the character of one's evidence) made by Thomas Kelly (2005).

A rational person doesn’t believe just anything. There are limits on what it is rational to believe. How wide are these limits? That’s the main question that interests me here. But a secondary question immediately arises: What factors impose these limits? A first stab is to say that one’s evidence determines what it is epistemically permissible for one to believe. Many will claim that there are further, non-evidentiary factors relevant to the epistemic rationality of belief. I will be ignoring the (...) details of alternative answers in order to focus on the question of what kind of rational constraints one’s evidence puts on belief. Our main question concerns how far epistemic permission and obligation can come apart.1 Suppose I am epistemically permitted to believe P, i.e., it would not be irrational for me to believe it. Am I thereby obliged to believe P, or are other options rationally available to me?2 Might I be equally rational in remaining agnostic about P, or even believing not-P? Or could even a slightly stronger or weaker degree of confidence be just as reasonable? (shrink)

How should one react when one has a belief, but knows that other people—who have roughly the same evidence as one has, and seem roughly as likely to react to it correctly—disagree? This paper argues that the disagreement of other competent inquirers often requires one to be much less confident in one’s opinions than one would otherwise be.

Science relies on models and idealizations that are known not to be true. Even so, science is epistemically reputable. To accommodate science, epistemology should focus on understanding rather than knowledge and should recognize that the understanding of a topic need not be factive. This requires reconfiguring the norms of epistemic acceptability. If epistemology has the resources to accommodate science, it will also have the resources to show that art too advances understanding.

Arguments from disagreement against moral realism begin by calling attention to widespread, fundamental moral disagreement among a certain group of people. Then, some skeptical or anti-realist-friendly conclusion is drawn. Chapter 2 proposes that arguments from disagreement share a structure that makes them vulnerable to a single, powerful objection: they self-undermine. For each formulation of the argument from disagreement, at least one of its premises casts doubt either on itself or on one of the other premises. On reflection, this shouldn’t be (...) surprising. These arguments are intended to support very strong metaphysical or epistemological conclusions about morality. They must therefore employ very strong metaphysical or epistemological premises. But, given the pervasiveness of disagreement in philosophy, especially about metaphysics and epistemology, very strong premises are virtually certain to be the subject of widespread, intractable disagreement—precisely the sort of disagreement that proponents of these arguments think undermine moral claims. Thus, these arguments undermine their own premises. If Chapter 2’s argument is sound, it provides realists with a single, unified strategy for responding to any existing or forthcoming arguments from disagreement. (shrink)

There has been a recent explosion of interest in the epistemology of disagreement. Much of the recent literature is concerned with a particular range of puzzle cases (discussed in the Cases section of my paper). Almost all of the papers that contribute to that recent literature make mention of questions about religious disagreement in ways that suggest that there are interesting connections between those puzzle cases and real life cases of religious disagreement. One important aim of my paper is to (...) cast doubt on that suggestion. More generally, the aim of my paper is to give a reasonably full account of the recent literature on the epistemology of disagreement, and then to give a serious discussion of some of the epistemological issues that are raised by real world religious disagreements. (shrink)

This article argues that there can be epistemic dilemmas: situations in which one faces conflicting epistemic requirements with the result that whatever one does, one is doomed to do wrong from the epistemic point of view. Accepting this view, I argue, may enable us to solve several epistemological puzzles.

Truth is standardly considered a requirement on epistemic acceptability. But science and philosophy deploy models, idealizations and thought experiments that prescind from truth to achieve other cognitive ends. I argue that such felicitous falsehoods function as cognitively useful fictions. They are cognitively useful because they exemplify and afford epistemic access to features they share with the relevant facts. They are falsehoods in that they diverge from the facts. Nonetheless, they are true enough to serve their epistemic purposes. Theories that contain (...) them have testable consequences, hence are factually defeasible. (shrink)

How should you take into account the opinions of an advisor? When you completely defer to the advisor's judgment, then you should treat the advisor as a guru. Roughly, that means you should believe what you expect she would believe, if supplied with your extra evidence. When the advisor is your own future self, the resulting principle amounts to a version of the Reflection Principle---a version amended to handle cases of information loss. When you count an advisor as an epistemic (...) peer, you should give her conclusions the same weight as your own. Denying that view---call it the ``equal weight view''---leads to absurdity: the absurdity that you could reasonably come to believe yourself to be an epistemic superior to an advisor simply by noting cases of disagreement with her, and taking it that she made most of the mistakes. Accepting the view seems to lead to another absurdity: that one should suspend judgment about everything that one's smart and well-informed friends disagree on, which means suspending judgment about almost everything interesting. But despite appearances, the equal weight view does not have this absurd consequence. Furthermore, the view can be generalized to handle cases involving not just epistemic peers, but also epistemic superiors and inferiors. (shrink)

Conciliationism is a view—well, a family of views—in the epistemology of disagreement. The idea, simply put, is that, in a wide range of cases where you find yourself in disagreement with another reasoner about the truth of some proposition, you are rationally obliged to adjust your credence in the direction of hers. Conciliationism enjoys a fair bit of prima facie plausibility. Most versions of it, however, suffer from a common (and rather obvious) problem: self-incrimination. Although there is some recognition in (...) the recent literature on disagreement that there is a problem in this vicinity, it, more often than not, is completely ignored. When it is not completely ignored, both the conciliationists and their critics tend to frame the problem incorrectly. As a result, they end up focusing most of their attention on pseudo-problems rather than the genuine worry. Furthermore, even when they have hit on the genuine worry, conciliationists have tended to give surprising and implausible responses to it. Even by their own lights, conciliationists aren’t justified in believing their conciliationist theses. In this paper, I argue that it’s time to come clean. Time to look for a view on the epistemic significance of disagreement that we can actually be justified in believing. (shrink)

The question that will be the focus of this paper is this: what is the significance of disagreement between those who are epistemic peers? There are two answers to this question found in the recent literature. On the one hand, there are those who hold that one can continue to rationally believe that p despite the fact that one’s epistemic peer explicitly believes that not-p. I shall call those who hold this view nonconformists. In contrast, there are those who hold (...) that one cannot continue to rationally believe that p when one is faced with an epistemic peer who explicitly believes that not-p. I shall call those who hold this view conformists. Inthis paper, I shall argue that neither nonconformism nor conformism provides a plausible account of the epistemic significance of peer disagreement. I shall then develop my justificationist account of peer disagreement’s epistemic significance. Whereas current views maintain that disagreement, by itself, either simply does or does not possess epistemic power, my account holds that its epistemic power, or lack thereof, is explainable in terms of its interaction with other features,particularly the degree of justified confidence with which the belief in question is held and the presence of information that one possesses about one’s own epistemic situation. (shrink)

My conclusion will be that, more often than we might have thought, suspension of judgment is the epistemically proper attitude. It follows that in such cases we lack reasonable belief and so, at least on standard conceptions, knowledge. This is a kind of contingent real-world skepticism that has not received the attention it deserves. I hope that this paper will help to bring this issue to life.

The question that will be the focus of this paper is this: what is the significance of disagreement between those who are epistemic peers? There are two answers to this question found in the recent literature. On the one hand, there are those who hold that one can continue to rationally believe that p despite the fact that one’s epistemic peer explicitly believes that not-p. I shall call those who hold this view nonconformists. In contrast, there are those who hold (...) that one cannot continue to rationally believe that p when one is faced with an epistemic peer who explicitly believes that not-p. I shall call those who hold this view conformists. Inthis paper, I shall argue that neither nonconformism nor conformism provides a plausible account of the epistemic significance of peer disagreement. I shall then develop my justificationist account of peer disagreement’s epistemic significance. Whereas current views maintain that disagreement, by itself, either simply does or does not possess epistemic power, my account holds that its epistemic power, or lack thereof, is explainable in terms of its interaction with other features,particularly the degree of justified confidence with which the belief in question is held and the presence of information that one possesses about one’s own epistemic situation. (shrink)