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.

Abstract: Theories of epistemic rationality that take disagreement (or other higher-order evidence) seriously tend to be “modest” in a certain sense: they say that there are circumstances in which it is rational to doubt their correctness. Modest views have been criticized on the grounds that they undermine themselves—they’re self-defeating. The standard Self-Defeat Objections depend on principles forbidding epistemically akratic beliefs; but there are good reasons to doubt these principles—even New Rational Reflection, which was designed to allow for certain special cases (...) that are intuitively akratic. On the other hand, if we construct a Self-Defeat Objection without relying on anti-akratic principles, modest principles turn out not to undermine themselves. In the end, modesty should not be seen as a defect in a theory of rational belief. (shrink)

I argue that recognizing a distinct doxastic attitude called endorsement, along with the epistemic norms governing it, solves the self-undermining problem for conciliationism about disagreement. I provide a novel account of how the self-undermining problem works by pointing out the auxiliary assumptions the objection relies on. These assumptions include commitment to certain epistemic principles linking belief in a theory to following prescriptions of that theory. I then argue that we have independent reason to recognize the attitude of endorsement. Endorsement is (...) the attitude of resilient and committed advocacy which is appropriate for researchers to have toward their own theory. Recognizing the importance of endorsement, and of its resiliency, gives us reason to deny the epistemic principles that serve as auxiliary assumptions in the self-undermining objection. This defuses the objection, and provides additional support for the theory of endorsement. (shrink)

This article defends the Fixed Point Thesis: that it is always a rational mistake to have false beliefs about the requirements of rationality. The Fixed Point Thesis is inspired by logical omniscience requirements in formal epistemology. It argues to the Fixed Point Thesis from the Akratic Principle: that rationality forbids having an attitude while believing that attitude is rationally forbidden. It then draws out surprising consequences of the Fixed Point Thesis, for instance that certain kinds of a priori justification are (...) indefeasible and that misleading all-things-considered evidence about rational requirements is impossible. Finally, the Fixed Point Thesis is applied to defend the Right Reasons position on peer disagreement, according to which an agent who has drawn the correct conclusion from her evidence should retain belief in that conclusion even in the face of disagreeing peers. (shrink)

A familiar complaint about conciliatory approaches to disagreement is that they are self-defeating or incoherent because they ‘call for their own rejection’. This complaint seems to be influential but it isn’t clear whether conciliatory views call for their own rejection or what, if anything, this tells us about the coherence of such views. We shall look at two ways of developing this self-defeat objection and we shall see that conciliatory views emerge unscathed. A simple version of the self-defeat objection leaves (...) conciliatory views untouched. A subtle version of the objection contains a subtle but overlooked flaw. If the conciliatory view is right, it might be right to be dogmatically conciliatory (i.e., to continue to be conciliatory however objectionable this might seem to ourselves and to others). (shrink)

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.

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)

Conciliationism holds that disagreement of apparent epistemic peers often substantially undermines rational confidence in our opinions. Uniqueness principles say that there is at most one maximally rational doxastic response to any given batch of total evidence. The two views are often thought to be tightly connected. This paper distinguishes two ways of motivating conciliationism, and two ways that conciliationism may be undermined by permissive accounts of rationality. It shows how conciliationism can flourish under certain strongly permissive accounts of rationality. This (...) occurs when the motivation for conciliationism does not come from taking disagreement as evidence of one's own rational failings. However, divorcing the motive for conciliating from worries about rationality does not remove a feature of conciliationism that some find troubling: that conciliationism can lead to cases of “rational toxicity,” in which the most rational response to one's evidence involves violating some rational ideal. (shrink)

An introduction to the debate of the epistemic significance of peer disagreement. This article examines the epistemic significance of peer disagreement. It pursues the following questions: (1) How does discovering that an epistemic equal disagrees with you affect your epistemic justification for holding that belief? (e.g., does the evidence of it give you a defeater for you belief?) and (2) Can you rationally maintain your belief in the face of such disagreement? This article explains and motivates each of the central (...) positions, including steadfast views and conciliatory views of peer disagreement, while at the same time raising challenges for each of them. It concludes by speculating about new directions that the debate will take. (shrink)

‘Conciliationism’ is the view that disagreement with qualified disputants gives us a powerful reason for doubting our disputed views, a reason that will often be sufficient to defeat what would otherwise be strong evidential justification for our position. Conciliationism is disputed by many qualified philosophers, a fact that has led many to conclude that conciliationism is self-defeating. After examining one prominent response to this challenge and finding it wanting, I develop a fresh approach to the problem. I identify two levels (...) at which one may show epistemic deference—the level of one's credences and the level of one's reasoning—and show that in disagreements over conciliationism, deference at one level results in non-deference at the other. A commitment to epistemic deference therefore does not provide a rational reason to reduce confidence when conciliationism itself is disputed. After presenting the case for ‘resolute conciliationism’, I address two objections. (shrink)

Conciliatory theories of disagreement require that one lower one’s confidence in a belief in the face of disagreement from an epistemic peer. One question about which people might disagree is who should qualify as an epistemic peer and who should not. But when putative epistemic peers disagree about epistemic peerhood itself, then Conciliationism makes contradictory demands and paradoxes arise.

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)

It has often been noticed that conciliatory views of disagreement are "self-undermining" in a certain way: advocates of such views cannot consistently maintain them when other philosophers disagree. This leads to apparent problems of instability and even inconsistency. Does self-undermining, then, show conciliationism untenable? If so, the untenablity would extend not only to almost all views of disagreement, but to a wide range of other views supporting what one might call epistemic modesty: roughly, the idea that getting evidence that one (...) has made an epistemic error in arriving at one’s opinion may require adjusting that opinion. This paper argues that the phenomenon of self-undermining does not disclose any defect in views mandating epistemic modesty. Instead, it highlights an uncomfortable but natural consequence of reflecting on one's own possible epistemic imperfections, a sort of reflection that tends to cause epistemic ideals to conflict. (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)

Contemporary epistemology of peer disagreement has largely focused on our immediate normative response to prima facie instances of disagreement. Whereas some philosophers demand that we should withhold judgment (or moderate our credences) in such cases, others argue that, unless new evidence becomes available, disagreement at best gives us reason to demote our interlocutor from his peer status. But what makes someone an epistemic peer in the first place? This question has not received the attention it deserves. I begin by surveying (...) different notions of ‘epistemic peer’ that have been peddled in the contemporary literature, arguing that they tend to build normative assumptions about the correct response to disagreement into the notion of peerhood. Instead, I argue, epistemic peerhood needs to be taken seriously in its own right. Importantly, for epistemic agents to count as peers, they should exhibit a comparable degree of reflective awareness of the character and limitations of their own knowledge. (shrink)

Sometimes we get evidence of our own epistemic malfunction. This can come from finding out we’re fatigued, or have been drugged, or that other competent and well-informed thinkers disagree with our beliefs. This sort of evidence seems to seems to behave differently from ordinary evidence about the world. In particular, getting such evidence can put agents in a position where the most rational response involves violating some epistemic ideal.

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)

"A sequel to Pollock's How to Build a Person, this volume builds upon that theoretical groundwork for the implementation of rationality through artificial ...

Evidentialism is the thesis that a person is justified in believing a proposition iff the person's evidence on balance supports that proposition. In discussing epistemological issues associated with disagreements among epistemic peers, some philosophers have endorsed principles that seem to run contrary to evidentialism, specifying how one should revise one's beliefs in light of disagreement. In this paper, I examine the connection between evidentialism and these principles. I argue that the puzzles about disagreement provide no reason to abandon evidentialism and (...) that there are no true general principles about justified responses to disagreement other than the general evidentialist principle. I then argue that the puzzles about disagreement are primarily puzzles about the evidential impact of higher - order evidence – evidence about the significance or existence of ordinary, or first- order, evidence. I conclude by arguing that such higher - order evidence can often have a profound effect on the justification of first- order beliefs. (shrink)

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)

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.

Responding rationally to the information that others disagree with one’s beliefs requires assessing the epistemic credentials of the opposing beliefs. Conciliatory accounts of disagreement flow in part from holding that these assessments must be independent from one’s own initial reasoning on the disputed matter. I argue that this claim, properly understood, does not have the untoward consequences some have worried about. Moreover, some of the difficulties it does engender must be faced by many less conciliatory accounts of disagreement.

You and I have been colleagues for ten years, during which we have tirelessly discussed the reasons both for and against the existence of God. There is no argument or piece of evidence bearing directly on this question that one of us is aware of that the other is not—we are, then, evidential equals relative to the topic of God’s existence. There is also no cognitive virtue or capacity, or cognitive vice or incapacity, that one of us possesses that the (...) other does not—we are, then, also cognitive equals relative to the question at issue. Given this evidential and cognitive equality, combined with the fact that we have fully disclosed to one another all of our reasons and arguments relative to this topic, we are epistemic peers with respect to the question whether God exists. Yet despite the symmetry of our epistemic positions, we deeply disagree about the answer to this question. What response does rationality require in such a case, where epistemic peers disagree over a question despite there being no apparent asymmetries between them? (shrink)

The goal of this paper is to frame a theory of reasons--what they are, how they support actions or conclusions--using the tools of default logic. After sketching the basic account of reasons as provided by defaults, I show how it can be elaborated to deal with two more complicated issues: first, situations in which the priority relation among defaults, and so reasons as well, is itself established through default reasoning; second, the treatment of undercutting defeat and exclusionary reasons. Finally, and (...) by way of application, I show how the resulting account can shed some light on Jonathan Dancy's argument from reason holism to a form of extreme particularism in moral theory. (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.

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.

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)

This work explores some ways in which logics for defeasible reasoning can be applied to questions in epistemology. It's naturally thought of as developing four applications: The first is concerned with simple epistemic rules, such as "If you perceives that X, then you ought to believe that X" and "If you have outstanding testimony that X, then you ought to believe that X." Anyone who thinks that such rules have a place in our accounts of epistemic normativity must explain what (...) happens in cases where they come into conflict —such as one where you perceive a red object and are told that it is blue. The literature has gone in two directions: The first suggests that rules have built-in unless-clauses specifying the circumstances under which they fail to apply; the second that rules do not specify what attitudes you ought to have, but only what counts in favor or against having those attitudes. I express these two different ideas in a defeasible logic framework and demonstrate that there's a clear sense in which they are equivalent. The second application uses a defeasible logic to solve an important puzzle about epistemic rationality, involving higher-order evidence, or, roughly, evidence about our capacities for evaluating evidence. My solution has some affinities with the so-called conflicting-ideals view. The third application, then, is a characterization of this view in logical terms: I suggest that it should be thought of as an unconventional metaepistemological view, according to which epistemic requirements are not exceptionless, but defeasible and governed by a comparatively weak logic. Finally, the fourth application is in the burgeoning debate about the epistemic significance of disagreement. The intuitive conciliatory views say, roughly, that you ought to become less confident in your take on some question X, if you learn that an epistemic equal disagrees with you about X. I propose to think of conciliationism as a defeasible reasoning policy, develop a mathematically precise model of it, and use it to solve one of the most pressing problems for conciliatory views: Given that there are disagreements about these views themselves, they can self-defeat and issue inconsistent recommendations. (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)

One of the most striking characteristics of human beings is their ability to function successfully in complex environments about which they know very little. In light of our pervasive ignorance, we cannot get around in the world just reasoning deductively from our prior beliefs together with new perceptual input. As our conclusions are not guaranteed to be true, we must countenance the possibility that new information will lead us to change our minds, withdrawing previously adopted beliefs. In this sense, our (...) reasoning is “defeasible”. The question arises how defeasible reasoning works, or ought to work. In particular we need rules governing what a cognizer ought to believe given a set of interacting arguments some of which defeat others. That is what is called a “semantics” for defeasible reasoning, and this chapter will propose a new semantics that avoids certain clear counter-examples to all existing semantics. (shrink)

The question addressed in this paper is how the degree of justification of a belief is determined. A conclusion may be supported by several different arguments, the arguments typically being defeasible, and there may also be arguments of varying strengths for defeaters for some of the supporting arguments. What is sought is a way of computing the “on sum” degree of justification of a conclusion in terms of the degrees of justification of all relevant premises and the strengths of all (...) relevant reasons. (shrink)

In this volume, John Horty brings to bear his work in logic to present a framework that allows for answers to key questions about reasons and reasoning, namely: What are reasons, and how do they support actions or conclusions?

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)