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)

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.

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)

According to moral intuitionism, at least some moral seeming states are justification-conferring. The primary defense of this view currently comes from advocates of the standard account, who take the justification-conferring power of a moral seeming to be determined by its phenomenological credentials alone. However, the standard account is vulnerable to a problem. In brief, the standard account implies that moral knowledge is seriously undermined by those commonplace moral disagreements in which both agents have equally good phenomenological credentials supporting their disputed (...) moral beliefs. However, it is implausible to think that commonplace disagreement seriously undermines moral knowledge, and thus it is implausible to think that the standard account of moral intuitionism is true. (shrink)

This new edition of the classic Contemporary Theories of Knowledge has been significantly updated to include analyses of the recent literature in epistemology.

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)

We often get evidence that bears on the reliability of some of our own first-order reasoning. The rational response to such “higher-order” evidence would seem to depend on a rational assessment of how reliable we can expect that reasoning to be, in light of the higher-order evidence. “Independence” principles are intended to constrain this reliability-assessment, so as to prevent question-begging reliance on the very reasoning being assessed. However, extant formulations of Independence principles tend to be vague or ambiguous, and coming (...) up with a tolerably precise formulation turns out to be tricky. This paper aims to make some progress toward developing a more precise Independence principle, and also to highlight some of the difficulties the project entails. The hope is to take a step toward understanding how rational belief is informed by evidence bearing on agents’ cognitive reliability. (shrink)

Normative Externalism argues that it is not important that people live up to their own principles. What matters, in both ethics and epistemology, is that they live up to the correct principles: that they do the right thing, and that they believe rationally. This stance, that what matters are the correct principles, not one's own principles, has implications across ethics and epistemology. In ethics, it undermines the ideas that moral uncertainty should be treated just like factual uncertainty, that moral ignorance (...) frequently excuses moral wrongdoing, and that hypocrisy is a vice. In epistemology, it suggests we need new treatments of higher-order evidence, and of peer disagreement, and of circular reasoning, and the book suggests new approaches to each of these problems. Although the debates in ethics and in epistemology are often conducted separately, putting them in one place helps bring out their common themes. One common theme is that the view that one should live up to one's own principles looks less attractive when people have terrible principles, or when following their own principles would lead to riskier or more aggressive action than the correct principles. Another common theme is that asking people to live up to their principles leads to regresses. It can be hard to know what action or belief complies with one's principles. And now we can ask, in such a case should a person do what they think their principles require, or what their principles actually require? Both answers lead to problems, and the best way to avoid these problems is to simply say people should follow the correct principles. (shrink)

For many epistemologists, and for many philosophers more broadly, it is axiomatic that rationality requires you to take the doxastic attitudes that your evidence supports. Yet there is also another current in our talk about rationality. On this usage, rationality is a matter of the right kind of coherence between one's mental attitudes. Surprisingly little work in epistemology is explicitly devoted to answering the question of how these two currents of talk are related. But many implicitly assume that evidence -responsiveness (...) guarantees coherence, so that the rational impermissibility of incoherence will just fall out of the putative requirement to take the attitudes that one's evidence supports, and so that coherence requirements do not need to be theorized in their own right, apart from evidential reasons. In this paper, I argue that this is a mistake, since coherence and evidence -responsiveness can in fact come into conflict. More specifically, I argue that in cases of misleading higher-order evidence, there can be a conflict between believing what one's evidence supports and satisfying a requirement that I call “inter-level coherence ”. This illustrates why coherence requirements and evidential reasons must be separated and theorized separately. (shrink)

In his Principles of Philosophy, Descartes says, Finally, it is so manifest that we possess a free will, capable of giving or withholding its assent, that this truth must be reckoned among the first and most common notions which are born with us.

The fact of moral disagreement when conjoined with Conciliationism, an independently attractive view about the epistemic significance disagreement, seems to entail moral skepticism. This worries those who like Conciliationism, the independently attractive view, but dislike moral skepticism. Others, equally inclined against moral skepticism, think this is a reductio of Conciliationism. I argue that they are both wrong. There is no reductio and nothing to worry about.

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)

Plausibly, you should believe what your total evidence supports. But cases of misleading higher-order evidence—evidence about what your evidence supports—present a challenge to this thought. In such cases, taking both first-order and higher-order evidence at face value leads to a seemingly irrational incoherence between one’s first-order and higher-order attitudes: you will believe P, but also believe that your evidence doesn’t support P. To avoid sanctioning tension between epistemic levels, some authors have abandoned the thought that both first-order and higher-order evidence (...) have rational bearing. This sacrifice is both costly and unnecessary. We propose a principle, Evidential Calibration, which requires rational agents to accommodate first-order evidence correctly, while allowing rational uncertainty about what to believe. At the same time, it rules out irrational tensions between epistemic levels. We show that while there are serious problems for some views on which we can rationally believe, “P, but my evidence doesn’t support P”, Evidential Calibration avoids these problems. An important upshot of our discussion is a new way to think about the relationship between epistemic levels: why first-order and higher-order attitudes should generally be aligned, and why it is sometimes—though not always—problematic when they diverge. (shrink)

This paper is about how moral disagreement matters for metaethics. It has four parts. In the first part I argue that moral facts are subject to a certain epistemic accessibility requirement. Namely, moral facts must be accessible to some possible agent. In the second part I show that because this accessibility requirement on moral facts holds, there is a route from facts about the moral disagreements of agents in idealized conditions to conclusions about what moral facts there are. In the (...) third part I build on this route to show that (*) if there is significant moral disagreement in idealized conditions, then our understanding of morality is fatally flawed and we should accept relativism over non-naturalism and quasi-realism. So, if, like many, you think that there would be significant moral disagreement in idealized conditions, you should hold that our understanding of morality is fatally flawed and reject non-naturalism and quasi-realism. In the fourth part of this paper I show that (*) undermines the plausibility of non-naturalism, quasi-realism, and the view that our understanding of morality is not fatally flawed even if we do not have sufficient reason to believe that there would be significant moral disagreement in idealized conditions. (shrink)

This article is about the implications of a conciliatory view about the epistemology of peer disagreement for our moral beliefs. Many have endorsed a conciliatory view about the epistemology of peer disagreement according to which if we find ourselves in a disagreement about some matter with another whom we should judge to be our epistemic peer on that matter, we must revise our judgment about that matter. This article focuses on three issues about the implications of conciliationism for our moral (...) beliefs. The first is whether there is an asymmetry between the implications of conciliationism for the epistemic status of our moral beliefs and the implications of conciliationism for the epistemic status of our non-moral beliefs; for instance, some have argued that conciliationism leads to epistemological moral skepticism but not to epistemological nonmoral skepticism. The second is what the implications of conciliationism are for the epistemic status of particular moral beliefs. The third is whether conciliationism's impact on the epistemic status of our moral beliefs has practical implications. (shrink)

In this paper, I offer two counterexamples to the so-called ‘Uniqueness Thesis.’ As one of these examples rely on the thesis that it is possible for a justified belief to be based on an inconsistent body of evidence, I also offer reasons for this further thesis. On the assumption that doxastic justification entails propositional justification, the counterexamples seem to work.

An important principle in the epistemology of disagreement is Independence, which states, “In evaluating the epistemic credentials of another’s expressed belief about P, in order to determine how (or whether) to modify my own belief about P, I should do so in a way that doesn’t rely on the reasoning behind my initial belief about P” (Christensen 2011, 1-2). I present a series of new counterexamples to both Independence and also a revised, more widely applicable, version of it. I then (...) formulate and endorse a third version of Independence that avoids those counterexamples. Lastly, I show how this third version of Independence reveals two new ways one may remain steadfast in the face of two real life disagreements: one about God’s existence and one about moral realism. (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)

In this article, I propose, defend, and apply a principle for applied ethics. According to this principle, we should exercise moral caution, at least when we can. More formally, the principle claims that if you should believe or suspend judgment that doing an action is a serious moral wrong, while knowing that not doing that action is not morally wrong, then you should not do that action. After motivating this principle, I argue that it has significant application in applied ethics. (...) The application to applied ethics comes by way of the epistemic significance of disagreement. Though such a principle has perhaps a number of applications in applied ethics, my focus here is limited to the question of whether it is morally permissible to eat animals for pleasure. (shrink)

Australasian Journal of Philosophy, Volume 92, Issue 2, Page 365-377, June 2014.

Conciliationists about peer disagreement hold that when one disagrees with an epistemic peer about some proposition p, one should significantly change one's view about p. Many arguments for conciliationism appeal to a principle Christensen [2011] dubs Independence. Independence says that evaluations of the beliefs of those with whom one disagrees should not be made on the basis of one's initial reasoning about p. In this paper, I show that this principle is false. I also show that two weaker principles that (...) vindicate conciliationism are either false, unmotivated, or both. (shrink)

This item was published as 'Appendix 3: An Implication of the k-option Condorcet jury mechanism for the probability of cycles' in List and Goodin (2001) http://eprints.lse.ac.uk/705/. Standard results suggest that the probability of cycles should increase as the number of options increases and also as the number of individuals increases. These results are, however, premised on a so-called "impartial culture" assumption: any logically possible preference ordering is assumed to be as likely to be held by an individual as any other. (...) The present chapter shows, in the three-option case, that given suitably systematic, however slight, deviations from an impartial culture situation, the probability of a cycle converges either to zero (more typically) or to one (less typically) as the number of individuals increases. (shrink)

This paper generalises the classical Condorcet jury theorem from majority voting over two options to plurality voting over multiple options. The paper further discusses the debate between epistemic and procedural democracy and situates its formal results in that debate. The paper finally compares a number of different social choice procedures for many-option choices in terms of their epistemic merits. An appendix explores the implications of some of the present mathematical results for the question of how probable majority cycles (as in (...) Condorcet's paradox) are in large electorates. (shrink)

Recent authors have drawn attention to a new kind of defeating evidence commonly referred to as higher-order evidence. Such evidence works by inducing doubts that one’s doxastic state is the result of a flawed process – for instance, a process brought about by a reason-distorting drug. I argue that accommodating defeat by higher-order evidence requires a two-tiered theory of justification, and that the phenomenon gives rise to a puzzle. The puzzle is that at least in some situations involving higher-order defeaters (...) the correct epistemic rules issue conflicting recommendations. For instance, a subject ought to believe p, but she ought also to suspend judgment in p. I discuss three responses. The first resists the puzzle by arguing that there is only one correct epistemic rule, an Über-rule. The second accepts that there are genuine epistemic dilemmas. The third appeals to a hierarchy or ordering of correct epistemic rules. I spell out problems for all of these responses. I conclude that the right lesson to draw from the puzzle is that a state can be epistemically rational or justified even if one has what looks to be strong evidence to think that it is not. As such, the considerations put forth constitute a non question-begging argument for a kind of externalism. (shrink)

In deep disagreements local disagreements are intertwined with more general basic disagreements about the relevant evidence, standards of argument or proper methods of inquiry in that domain. The paper provides a more specific conception of deep disagreement along these lines and argues that while we should generally conciliate in cases of disagreement, this is not so in deep disagreements. The paper offers a general view of disagreement, holding roughly that one should moderate one’s credence towards uncertainty in so far as (...) disagreement with others provides undefeated higher order evidence that one might have made a mistake in one’s appreciation of the first order evidence. When applying this view to deep disagreement we get that in cases of deep disagreement higher order evidence from disagreement is rebutted or undercut by the nature of the disagreement. So, in cases of deep disagreement one should not moderate one’s credence. I finally argue that this gives a better general view of deep disagreement than views appealing to epistemic peers, personal information or independence. (shrink)

Many views rely on the idea that it can never be rational to have high confidence in something like, “P, but my evidence doesn’t support P.” Call this idea the “Non-Akrasia Constraint”. Just as an akratic agent acts in a way she believes she ought not act, an epistemically akratic agent believes something that she believes is unsupported by her evidence. The Non-Akrasia Constraint says that ideally rational agents will never be epistemically akratic. In a number of recent papers, the (...) Non-Akrasia Constraint has been called into question. The goal of this paper is to defend it... for the most part. (shrink)

Mainstream epistemology is a highly theoretical and abstract enterprise. Traditional epistemologists rarely present their deliberations as critical to the practical problems of life, unless one supposes—as Hume, for example, did not—that skeptical worries should trouble us in our everyday affairs. But some issues in epistemology are both theoretically interesting and practically quite pressing. That holds of the problem to be discussed here: how laypersons should evaluate the testimony of experts and decide which of two or more rival experts is most (...) credible. It is of practical importance because in a complex, highly specialized world people are constantly confronted with situations in which, as comparative novices, they must turn to putative experts for intellectual guidance or assistance. It is of theoretical interest because the appropriate epistemic considerations are far from transparent; and it is not clear how far the problems lead to insurmountable skeptical quandaries. This paper does not argue for flat-out skepticism in this domain; nor, on the other hand, does it purport to resolve all pressures in the direction of skepticism. It is an exploratory paper, which tries to identify problems and examine some possible solutions, not to establish those solutions definitively. (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)

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)

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)

Can we have objective knowledge of right and wrong, of how we should live and what there is reason to do? Can it be anything but luck when our moral beliefs are true? Kieran Setiya confronts these questions in their most compelling and articulate forms, and argues that if there is objective ethical knowledge, human nature is its source.

Can we turn the screw on counter-examples to the KK principle (that if one knows that P, one knows that one knows that P)? The idea is to construct cases in which one knows that P, but the epistemic status for one of the proposition that one knows that P is much worse than just one’s not knowing it. Of course, since knowledge is factive, there can’t be cases in which one knows that P and knows that one doesn’t know (...) that P (we can’t strengthen ¬KKp to K¬Kp)! If we can construct such cases, we may be able to use them to understand some puzzling epistemic phenomena. (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)

The phenomenon of persistent ethical disagreement is often cited in connection with the question of whether there is any ‘‘absolute’’ morality, or whether, instead, morality is in some sense merely ‘‘a matter of personal opinion’’. Citing disagreement, many people who hold strong views about controversial issues such as the permissibility of abortion, eating meat, or the death penalty deny that these views are anything more than ‘‘personal beliefs’’. But while there might be inconsistencies lurking in this position, it is not (...) obviously at fault for according the facts about disagreement some epistemic weight. This paper addresses the question of whether and to what extent moral disagreement undermines moral knowledge. The most familiar arguments from disagreement in the literature purport to establish conclusions about the metaphysics of morality: that there are no moral facts, or that there are no moral properties, or that the moral facts are relative rather than absolute. Of course, the conclusions of some such metaphysical arguments might be perfectly consistent with the existence of considerable moral knowledge. For example, even if there is some successful argument from disagreement to the conclusion that moral facts are relative rather than absolute, this might very well be consistent with our having just as much moral knowledge as we.. (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)