Some philosophers believe that when epistemic peers disagree, each has an obligation to accord the other's assessment the same weight as her own. I first make the antecedent of this Equal-Weight View more precise, and then I motivate the View by describing cases in which it gives the intuitively correct verdict. Next I introduce some apparent counterexamples – cases of apparent peer disagreement in which, intuitively, one should not give equal weight to the other party's assessment. To defuse these apparent (...) counterexamples, an advocate of the View might try to explain how they are not genuine cases of peer disagreement. I examine David Christensen's and Adam Elga's explanations and find them wanting. I then offer a novel explanation, which turns on a distinction between knowledge from reports and knowledge from direct acquaintance. Finally, I extend my explanation to provide a handy and satisfying response to the charge of self-defeat. (shrink)

How much should your confidence in your beliefs be shaken when you learn that others – perhaps 'epistemic peers' who seem as well-qualified as you are – hold beliefs contrary to yours? This article describes motivations that push different philosophers towards opposite answers to this question. It identifies a key theoretical principle that divides current writers on the epistemology of disagreement. It then examines arguments bearing on that principle, and on the wider issue. It ends by describing some outstanding questions (...) that thinking about this issue raises. (shrink)

Experts take sides in standing scholarly disagreements. They rely on the epistemic reasons favorable to their side to justify their position. It is argued here that no position actually has an overall balance of undefeated reasons in its favor. Candidates for such reasons include the objective strength of the rational support for one side, the special force of details in the case for one side, and a summary impression of truth. All such factors fail to justify any position.

This is a book about normativity -- where the central normative terms are words like 'ought' and 'should' and their equivalents in other languages. It has three parts: The first part is about the semantics of normative discourse: what it means to talk about what ought to be the case. The second part is about the metaphysics of normative properties and relations: what is the nature of those properties and relations whose pattern of instantiation makes propositions about what ought to (...) be the case true. The third part is about the epistemology of normative beliefs: how we could ever know, or even have rational or justified belief in, propositions about what ought to be the case. (shrink)

Philosophers often find themselves in disagreement with contemporary philosophers they know full well to be their epistemic superiors on the topics relevant to the disagreement. This looks epistemically irresponsible. I offer a detailed investigation of this problem of the reflective epistemic renegade. I argue that although in some cases the renegade is not epistemically blameworthy, and the renegade situation is significantly less common than most would think, in a troublesome number of cases in which the situation arises the renegade is (...) blameworthy in her disagreement with recognized epistemic superiors. I also offer some thoughts on what it would mean for philosophical practice for us to refrain from being renegades. Finally, I show how a new kind of radical skepticism emerges from modest theses regarding the renegade. (shrink)

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.

Looking back on it, it seems almost incredible that so many equally educated, equally sincere compatriots and contemporaries, all drawing from the same limited stock of evidence, should have reached so many totally different conclusions---and always with complete certainty.

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)

Moral disagreement has long been thought to create serious problems for certain views in metaethics. More specifically, moral disagreement has been thought to pose problems for any metaethical view that rejects relativism—that is, for any view that implies that whenever two thinkers disagree about a moral question, at least one of those thinkers’ beliefs about the question is not correct. In this essay, I shall outline a solution to one of these problems. As I shall argue, it turns out in (...) the end that this problem is not really a special problem about moral disagreement at all: it is a general problem about disagreement as such. For this reason, in the later sections of this essay, I shall turn to some general questions in epistemology, about the epistemic significance of disagreement. (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)

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.

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.

I believe that the sort of disagreements we encounter in philosophy—disagreements that often take the form that I have elsewhere called system- atic peer disagreements—make it unreasonable to think that there is any knowledge, or even justified belief, when the disagreements themselves are systematic. I readily acknowledge that this skeptical view is quite controversial; I suspect many are unconvinced. However, I will not be defending it here. Rather, I will be exploring a worry, or set of worries, that arise on (...) the assumption that this view is correct. For if it is unreasonable to think that there is justified belief in contexts of systematic philosophical disagreements, by what right do we continue to advance philosophical claims in such contexts? Indeed, by what right do we believe the philosophical claims we advance? And if we don’t believe them, why do we advance them in the first place? An inability to respond to these worries would leave us with the dis- tinct impression that the practice or activity of philosophy is quite suspect: what sort of practice or activity would have us believe unreasonably, assert unwarrantedly, and perhaps exhibit insincerity to boot? (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)

While puzzles concerning the epistemic significance of disagreement are typically motivated by looking at the widespread and persistent disagreements we are aware of, almost all of the literature on the epistemic significance of disagreement has focused on cases idealized peer disagreement. This fact might itself be puzzling since it doesn’t seem that we ever encounter disagreements that meet the relevant idealized conditions. In this paper I hope to somewhat rectify this matter. I begin by closely examining what an idealized case (...) of peer disagreement looks like and what the Equal Weight View (EWV) of disagreement claims about the epistemic significance of such disagreements. After briefly defending the verdicts of the EWV in idealized disagreements I proceed to unpack the implications of stripping away the idealized conditions. In doing I show both why it is important to focus on idealized cases of peer disagreement and what we can learn from such cases that applies to the everyday cases of disagreement of which we are very familiar. (shrink)

Much of the literature on the epistemology of disagreement focuses on the rational responses to disagreement, and to disagreement with an epistemic peer in particular. The Equal Weight View claims that in cases of peer disagreement each dissenting peer opinion is to be given equal weight and, in a case of two opposing equally-weighted opinions, each party should adopt the attitude which ‘splits the difference’. The Equal Weight View has been taken by both its critics and its proponents to have (...) quite drastic skeptical ramifications given contingent empirical facts that we are aware of regarding disagreements in philosophy, religion, science, and politics. In this paper,we begin by clarifying the central claims of the Equal Weight View (Section 2) and then examine two routes from the Equal Weight View to skepticism about such matters that have been explored in the literature. The first claims that our awareness of peers or experts who disagree with us about such issues requires that we abandon our beliefs on these issues (Section 3). The second claims that our awareness of merely possible peers or experts who disagree with us requires us to abandon our beliefs (Section 4). We find both routes from the Equal Weight View to a form of skepticism defective. However, there are nearby considerations, explored in Sections 5 and 6,which (for better or worse) do lead to at least some skeptical consequences for the Equal WeightView, albeit for different reasons. (shrink)

The equal weight view says that if you discover that you disagree with a peer, you should decrease your confidence that you are in the right. Since peer disagreement seems to be quite prevalent, the equal weight view seems to tell us that we cannot reasonably believe many of the interesting things we believe because we can always count on a peer to contest the interesting things that we believe. While the equal weight view seems to have skeptical implications, few (...) epistemologists worry about these implications because the equal weight view is quickly falling out of favor. In this paper, I present an analogical argument for the view and defend it from critics who think that we can justifiably retain confidence in the face of peer disagreement. (shrink)

The Equal Weight View of disagreement says that if an agent sees that an epistemic peer disagrees with her about p, the agent should change her credence in p to half way between her initial credence, and the peer’s credence. But it is hard to believe the Equal Weight View for a surprising reason; not everyone believes it. And that means that if one did believe it, one would be required to lower one’s belief in it in light of this (...) peer disagreement. Brian Weatherson explores the options for how a proponent of the Equal Weight View might respond to this difficulty, and how this challenge fits into broader arguments against the Equal Weight View. (shrink)

Conciliatory views about disagreement with one’s epistemic peers lead to a somewhat troubling skeptical conclusion: that often, when we know others disagree, we ought to be (perhaps much) less sure of our beliefs than we typically are. One might attempt to extend this skeptical conclusion by arguing that disagreement with merely possible epistemic agents should be epistemically significant to the same degree as disagreement with actual agents, and that, since for any belief we have, it is possible that someone should (...) disagree in the appropriate way, we ought to be much less sure of all of our beliefs than we typically are. In this paper, I identify what I take to be the main motivation for thinking that actual disagreement is epistemically significant and argue that it does not also motivate the epistemic significance of merely possible disagreement. (shrink)

When one encounters disagreement about the truth of a factual claim from a trusted advisor who has access to all of one's evidence, should that move one in the direction of the advisor's view? Conciliatory views on disagreement say "yes, at least a little." Such views are extremely natural, but they can give incoherent advice when the issue under dispute is disagreement itself. So conciliatory views stand refuted. But despite first appearances, this makes no trouble for *partly* conciliatory views: views (...) that recommend giving ground in the face of disagreement about many matters, but not about disagreement itself. (shrink)

To what degree should we rely on our own resources and methods to form opinions about important matters? To what degree should we depend on various authorities, such as a recognized expert or a social tradition? In this provocative account of intellectual trust and authority, Richard Foley argues that it can be reasonable to have intellectual trust in oneself even though it is not possible to provide a defence of the reliability of one's faculties, methods and opinions that does not (...) beg the question. Moreover, he shows how this account of intellectual self-trust can be used to understand the degree to which it is reasonable to rely on alternative authorities. This book will be of interest to advanced students and professionals working in the fields of philosophy and the social sciences as well as anyone looking for a unified account of the issues at the centre of intellectual trust. (shrink)

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).

Conciliatory views of disagreement are an intuitive class of views on the epistemic significance of disagreement. Such views claim that making conciliation is often required upon discovering that another disagrees with you. One of the chief objections to these views of the epistemic significance of disagreement is that they are self-defeating. Since, there are disagreements about the epistemic significance of disagreement, such views can be turned on themselves, and this has been thought to be problematic. In this paper, I examine (...) several different incarnations of this objection and defend conciliatory views of disagreement from each of them, while making a modification regarding how such views should be understood. (shrink)

The Uniqueness Thesis, or rational uniqueness, claims that a body of evidence severely constrains one’s doxastic options. In particular, it claims that for any body of evidence E and proposition P, E justifies at most one doxastic attitude toward P. In this paper I defend this formulation of the uniqueness thesis and examine the case for its truth. I begin by clarifying my formulation of the Uniqueness Thesis and examining its close relationship to evidentialism. I proceed to give some motivation (...) for this strong epistemic claim and to defend it from several recent objections in the literature. In particular I look at objections to the Uniqueness Thesis coming from considerations of rational disagreement (can’t reasonable people disagree?), the breadth of doxastic attitudes(can’t what is justified by the evidence encompass more than one doxastic attitude?), borderline cases and caution (can’t it be rational to be cautious and suspend judgment even when the evidence slightly supports belief?), vagueness (doesn’t the vagueness of justification spell trouble for the Uniqueness Thesis?), and degrees of belief (doesn’t a finegrained doxastic picture present additional problems for the Uniqueness Thesis?). (shrink)

How should you update your (degrees of) belief about a proposition when you find out that someone else — as reliable as you are in these matters — disagrees with you about its truth value? There are now several different answers to this question — the question of `peer disagreement' — in the literature, but none, I think, is plausible. Even more importantly, none of the answers in the literature places the peer-disagreement debate in its natural place among the most (...) general traditional concerns of normative epistemology. In this paper I try to do better. I start by emphasizing how we cannot and should not treat ourselves as `truthometers' — merely devices with a certain probability of tracking the truth. I argue that the truthometer view is the main motivation for the Equal Weight View in the context of peer disagreement. With this fact in mind, the discussion of peer disagreement becomes more complicated, sensitive to the justification of the relevant background degrees of belief (including the conditional ones), and to some of the most general points that arise in the context of discussions of scepticism. I argue that thus understood, peer disagreement is less special as an epistemic phenomenon than may be thought, and so that there is very little by way of positive theory that we can give about peer disagreement in general. (shrink)

In epistemology the nagging voice of the sceptic has always been present, whispering that 'You can't know that you have hands, or just about anything else, because for all you know your whole life is a dream.' Philosophers have recently devised ingenious ways to argue against and silence this voice, but Bryan Frances now presents a highly original argument template for generating new kinds of radical scepticism, ones that hold even if all the clever anti-sceptical fixes defeat the traditional sceptic. (...) Sharp, witty, and fun to read, Scepticism Comes Alive will be highly provocative for anyone interested in knowledge and its limits. (shrink)

Two theses figure centrally in work on the epistemology of disagreement: Equal Weight (‘EW’) and Uniqueness (‘U’). According to EW, you should give precisely as much weight to the attitude of a disagreeing epistemic peer as you give to your own attitude. U has it that, for any given proposition and total body of evidence, some doxastic attitude is the one the evidence makes rational (justifies) toward that proposition. Although EW has received considerable discussion, the case for U has not (...) been critically evaluated. Endorsing U, we argue, commits one to the highly controversial thesis that whatever fixes your rational attitudes can do so only by fixing what evidence you have. This commitment imposes a relatively demanding requirement on justified belief in U, one that we argue is not satisfied by what is currently the strongest available case for U, due to Roger White [2005]. Our challenge to U makes more trouble for its proponents than do the worries about U expressed by Gideon Rosen [2001] and Thomas Kelly [2010]. Moreover, if Kelly [2010] is correct in thinking that EW “carries with it a commitment to” U—a claim which we accept for reasons similar to Kelly’s but is beyond this paper’s scope (but see Ballantyne and Coffman [forthcoming])—then our challenge to U bears importantly on EW: to the extent that our challenge to U succeeds, EW also suffers. (shrink)

The following three propositions appear to be individually defensible but jointly inconsistent: (1) reliability is a necessary condition on epistemic justification; (2) on contested matters in philosophy, my beliefs are not reliably formed; (3) some of these beliefs are epistemically justified. I explore the nature and scope of the problem, examine and reject some candidate solutions, compare the issue with ones arising in discussions about disagreement, and offer a brief assessment of our predicament.

The question I consider is this: -/- The Question: Can two people–who are, and realize they are, intellectually virtuous to about the same degree–both be rational in continuing knowingly to disagree after full disclosure (by each to the other of all the relevant evidence they can think of) while at the same time thinking that the other may well be rational too? -/- I distinguish two kinds of rationality–internal and external–and argue in section 1 that, whichever kind we have in (...) mind, the answer to The Question is ‘yes’ (though that positive answer is less wholehearted in the case of external rationality). Then, in section 2, I briefly make some more general remarks about when discovering a disagreement provides a defeater and when it doesn't. In the final section, I consider an important objection to the answer given in section 1 to The Question. (shrink)

According to one widely held view, a belief is fully justified only if it holds up against the strongest available counterarguments, and we can be appropriately confident that it does hold up only if there is free and open critical discussion of those beliefs between us and our epistemic peers. In this paper I argue that this common picture of ideal rational group inquiry interacts with epistemic problems concerning reasonable disagreement in a way that makes those problems particularly difficult to (...) resolve. By focusing on this idealized context, we get a clearer picture of the epistemic principles at issue. In the end, I argue that the best way to resolve the resulting epistemic conflicts is by appeal to the underdetermination of theory by evidence together with a principle of epistemic conservatism. (shrink)