This thesis is an investigation into the nature of epistemic justification. It brings together themes from traditional, individual-centred epistemology, and collective, group-centred epistemology. The first half of the thesis is concerned with the question of whether rationality is epistemically permissive; that is, whether one body of evidence can rationalise more than one doxastic attitude. In chapter 1, I argue that permissive cases are best understood as epistemic standard conflicts. Doing so provides us with a novel understanding of the arbitrariness objection (...) against permissivism and enables us to reduce questions about epistemic permissibility to questions about the nature of incommensurability. In chapter 2, I show that the defended understanding of permissive cases generalises by defending it against an objection from self-fulfilling beliefs. In chapter 3, I demonstrate that we can use this view of epistemic rationality to generate so-called divergence arguments which show that the epistemic status of group-level attitudes and member-level attitudes can rationally diverge. In the second half of the thesis, I develop a novel evidentialist theory of epistemic justification, called Continuous Evidentialism. Continuous Evidentialism is inspired by some general methodological reflections (chapter 4), which suggest that we should opt for a theory of epistemic justification that analyses the epistemic status of group-level attitudes and member-level attitudes continuously. According to Continuous Evidentialism, to have a justified belief is to possess sufficient evidence and utilise that evidence in an epistemically responsible way when forming the belief. While I argue that we can reduce epistemic responsibility to higher-order evidentialist requirements. In chapter 5, I develop a theory of evidence, evidence possession and epistemic basing. Chapters 6 - 8, discuss various complications of the proposed theory, having to do with the alleged defeasibility of justification (chapter 6), epistemic responsibility (chapter 7), and the proposed reduction of epistemic responsibility (chapter 8). In chapter 9, I compare Continuous Evidentialism to various extant accounts. (shrink)

While the epistemic significance of disagreement has been a popular topic in epistemology for at least a decade, little attention has been paid to logical disagreement. This monograph is meant as a remedy. The text starts with an extensive literature review of the epistemology of (peer) disagreement and sets the stage for an epistemological study of logical disagreement. The guiding thread for the rest of the work is then three distinct readings of the ambiguous term ‘logical disagreement’. Chapters 1 and (...) 2 focus on the Ad Hoc Reading according to which logical disagreements occur when two subjects take incompatible doxastic attitudes toward a specific proposition in or about logic. Chapter 2 presents a new counterexample to the widely discussed Uniqueness Thesis. Chapters 3 and 4 focus on the Theory Choice Reading of ‘logical disagreement’. According to this interpretation, logical disagreements occur at the level of entire logical theories rather than individual entailment-claims. Chapter 4 concerns a key question from the philosophy of logic, viz., how we have epistemic justification for claims about logical consequence. In Chapters 5 and 6 we turn to the Akrasia Reading. On this reading, logical disagreements occur when there is a mismatch between the deductive strength of one’s background logic and the logical theory one prefers (officially). Chapter 6 introduces logical akrasia by analogy to epistemic akrasia and presents a novel dilemma. Chapter 7 revisits the epistemology of peer disagreement and argues that the epistemic significance of central principles from the literature are at best deflated in the context of logical disagreement. The chapter also develops a simple formal model of deep disagreement in Default Logic, relating this to our general discussion of logical disagreement. The monograph ends in an epilogue with some reflections on the potential epistemic significance of convergence in logical theorizing. (shrink)

When a belief has been influenced, in part or whole, by factors that, by the believer's own lights, do not bear on the truth of the believed proposition, we can say that the belief has been, in a sense, arbitrarily formed. Can such beliefs ever be rational? It might seem obvious that they can't. After all, belief, supposedly, “aims at the truth.” But many epistemologists have come to think that certain kinds of arbitrary beliefs can, indeed, be rational. In this (...) paper, I want to do two things. First, I want to show that the claim that arbitrary beliefs can be rational is inconsistent with the conjunction of two other attractive claims: one saying that rationality requires a certain kind of epistemic immodesty, and one saying that rationality forbids certain kinds of self-ascriptions of epistemic luck. Second, I want to evaluate different ways one might respond to this inconsistent triad. I won't defend any response in particular, but I'll draw out some notable costs and benefits of each response, which may help shed light on the question of whether arbitrary beliefs can be rational. (shrink)

Evidential Uniqueness is the thesis that, for any batch of evidence, there’s a unique doxastic state that a subject with that evidence should have. One of the most common kinds of objections to views that violate Evidential Uniqueness are arbitrariness objections – objections to the effect that views that don’t satisfy Evidential Uniqueness lead to unacceptable arbitrariness. The goal of this paper is to examine a variety of arbitrariness objections that have appeared in the literature, and to assess the extent (...) to which these objections bolster the case for Evidential Uniqueness. After examining a number of different arbitrariness objections, I’ll conclude that, by and large, these objections do little to bolster the case for Evidential Uniqueness. (shrink)

Is it ever rational to suspend judgment about whether a particular doxastic attitude of ours is rational? An agent who suspends about whether her attitude is rational has serious doubts that it is. These doubts place a special burden on the agent, namely, to justify maintaining her chosen attitude over others. A dilemma arises. Providing justification for maintaining the chosen attitude would commit the agent to considering the attitude rational—contrary to her suspension on the matter. Alternatively, in the absence of (...) such justification, the attitude would be arbitrary by the agent's own lights, and therefore irrational from the agent's own perspective. So, suspending about whether an attitude of ours is rational does not cohere with considering it rationally preferable to other attitudes, and leads to a more familiar form of epistemic akrasia otherwise. (shrink)

Permissivism is the view that, sometimes, there is more than one doxastic attitude that is perfectly rationalised by the evidence. Impermissivism is the denial of Permissivism. Several philosophers, with the aim to defend either Impermissivism or Permissivism, have recently discussed the value of (im)permissive rationality. This paper focuses on one kind of value-conferring considerations, stemming from the so-called “truth-connection” enjoyed by rational doxastic attitudes. The paper vindicates the truth-connected value of permissive rationality by pursuing a novel strategy which rests on (...) two main planks: first, there is a distinction between a fine-grained and a coarse-grained type-individuation of belief-forming methods. Secondly, different kinds of decision-theoretic reasoning, i.e. expected-accuracy reasoning and accuracy-domination reasoning, must be paired with a fine-grained and a coarse-grained type-individuation of methods, respectively. I argue that while the first pair is wholly irrelevant to the question of the truth-connection, the second affords the means to a permissivist explanation of the truth-connected value of rationality. (shrink)

In the peer disagreement debate, three intuitively attractive claims seem to conflict: there is disagreement among peers on many important matters; peer disagreement is a serious challenge to one’s own opinion; and yet one should be able to maintain one’s opinion on important matters. I show that contrary to initial appearances, we can accept all three of these claims. Disagreement significantly shifts the balance of the evidence; but with respect to certain kinds of claims, one should nonetheless retain one’s beliefs. (...) And one should retain them even though these beliefs would not be supported by the new total evidence if one didn’t already hold them. (shrink)

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)

Does immorality necessarily involve irrationality? The question is often taken to be among the deepest in moral philosophy. But apparently deep questions sometimes admit of deflationary answers. In this case we can make way for a deflationary answer by appealing to dualism about rationality, according to which there are two fundamentally distinct notions of rationality: structural rationality and substantive rationality. I have defended dualism elsewhere. Here, I’ll argue that it allows us to embrace a sensible – I will not say (...) boring – moderate view about the relationship between immorality and irrationality: roughly, that immorality involves substantive irrationality, but not structural irrationality. I defend this moderate view, and argue that many of the arguments for less moderate views turn either on missing the distinction between substantive and structural rationality, or on misconstruing it. (shrink)

This chapter covers contemporary work on disagreement, detailing both the conceptual and normative issues in play in the debates in mainstream analytic epistemology, and how these relate to religious diversity and disagreement. §1 examines several sorts of disagreement, and considers several epistemological issues: in particular, what range of attitudes a body of evidence can support, how to understand higher-order evidence, and who counts as an epistemic “peer”. §2 considers how these questions surface when considering disagreements over religion, including debates over (...) the nature of evidence and truth in religion, epistemic humility, concerns about irrelevant influences and about divine hiddenness, and arguments over exclusivism, inclusivism, and pluralism. Finally, §3 summarizes the contributors’ essays in this volume. (shrink)

Suppose we learn that we have a poor track record in forming beliefs rationally, or that a brilliant colleague thinks that we believe P irrationally. Does such input require us to revise those beliefs whose rationality is in question? When we gain information suggesting that our beliefs are irrational, we are in one of two general cases. In the first case we made no error, and our beliefs are rational. In that case the input to the contrary is misleading. In (...) the second case we indeed believe irrationally, and our original evidence already requires us to fix our mistake. In that case the input to that effect is normatively superfluous. Thus, we know that information suggesting that our beliefs are irrational is either misleading or superfluous. This, I submit, renders the input incapable of justifying belief revision, despite our not knowing which of the two kinds it is. (shrink)

Peer review is often taken to be the main form of quality control on academic research. Usually journals carry this out. However, parts of maths and physics appear to have a parallel, crowd-sourced model of peer review, where papers are posted on the arXiv to be publicly discussed. In this paper we argue that crowd-sourced peer review is likely to do better than journal-solicited peer review at sorting papers by quality. Our argument rests on two key claims. First, crowd-sourced peer (...) review will lead on average to more reviewers per paper than journal-solicited peer review. Second, due to the wisdom of the crowds, more reviewers will tend to make better judgments than fewer. We make the second claim precise by looking at the Condorcet Jury Theorem as well as two related jury theorems developed specifically to apply to peer review. (shrink)

Permissivism is the thesis that, for some body of evidence and a proposition p, there is more than one rational doxastic attitude any agent with that evidence can take toward p. Proponents of uniqueness deny permissivism, maintaining that every body of evidence always determines a single rational doxastic attitude. In this paper, we explore the debate between permissivism and uniqueness about evidence, outlining some of the major arguments on each side. We then consider how permissivism can be understood as an (...) underdetermination thesis, and show how this moves the debate forward in fruitful ways: in distinguishing between different types of permissivism, in dispelling classic objections to permissivism, and in shedding light on the relationship between permissivism and evidentialism. (shrink)

ABSTRACTShould conciliating with disagreeing peers be considered sufficient for reaching rational beliefs? Thomas Kelly argues that when taken this way, Conciliationism lets those who enter into a disagreement with an irrational belief reach a rational belief all too easily. Three kinds of responses defending Conciliationism are found in the literature. One response has it that conciliation is required only of agents who have a rational belief as they enter into a disagreement. This response yields a requirement that no one should (...) follow. If the need to conciliate applies only to already rational agents, then an agent must conciliate only when her peer is the one irrational. A second response views conciliation as merely necessary for having a rational belief. This alone does little to address the central question of what is rational to believe when facing a disagreeing peer. Attempts to develop the response either reduce to the first response, or deem necessary an unnecessary doxastic revision, or imply that rational dilemmas obtain in cases where intuitively there are none. A third response tells us to weigh what our pre-disagreement evidence supports against the evidence from the disagreement itself. This invites epistemic akrasia. (shrink)

ABSTRACT In this paper, I defend a new solution to the problem of peer disagreement, the question as to how you should respond when you learn that your ‘epistemic peer’ disagrees with you about some issue. I consider four test cases that together impugn every extant full-blown theory about peer disagreement. I present my own solution, show that it delivers the intuitive verdict in the test cases and address some objections.

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)

What the rational thing to do in the face of disagreement by an epistemic peer is has been much discussed recently. Those who think that a peer’s disagreement is itself evidence against one’s belief, as many do, are committed to a special form of epistemic dependence. If such disagreement is really evidence, it seems reasonable to take it into account and to adjust one’s belief accordingly. But then it seems that the belief one ends up with depends, in part, on (...) what someone else believes, even if one does not know why that someone believes what he does. While the practical impossibility of finding actual cases of peer disagreement has been often noted, its conceptual possibility has gone unquestioned. Here we challenge this consensus and argue, first, that, strictly speaking, peer disagreement is impossible and, second, that cases of – all-too-common – near-peer disagreement present no special puzzle and require nothing more than adhering to standard principles of sensible epistemic conduct. In particular, we argue that in such cases there is no good reason to adopt the widely accepted principle that evidence of evidence is evidence. If so, even if one takes a near-peer’s disagreement as a reason for reexamining one’s belief, one is not epistemically dependent in the sense one would be if that disagreement were evidence concerning the matter in question. (shrink)

One explanation of rational peer disagreement is that agents find themselves in an epistemically permissive situation. In fact, some authors have suggested that, while evidence could be impermissive at the intrapersonal level, it is permissive at the interpersonal level. In this paper, I challenge such a claim. I will argue that, at least in cases of rational disagreement under full disclosure, there cannot be more interpersonal epistemically permissive situations than there are intrapersonal epistemically permissive situations. In other words, with respect (...) to cases of disagreement under full disclosure, I will argue that there is a necessary connection between interpersonal permissiveness and its intrapersonal counterpart. Specifically, I claim that a plausible principle of correct argumentation supports such a bridge. (shrink)

Rationality is intrapersonally permissive just in case there are multiple doxastic states that one agent may be rational in holding at a given time, given some body of evidence. One way for intrapersonal permissivism to be true is if there are epistemic supererogatory beliefs—beliefs that go beyond the call of epistemic duty. Despite this, there has been almost no discussion of epistemic supererogation in the permissivism literature. This paper shows that this is a mistake. It does this by arguing that (...) the most popular ways of responding to one of the major obstacles to any intrapersonally permissive all fall prey to the same problem. This problem is most naturally solved by positing a category of epistemically supererogatory belief. So intrapersonal epistemic permissivists should embrace epistemic supererogation. (shrink)

We offer a critical survey of the most discussed accounts of epistemic peer disagreement that are found in the recent literature. We also sketch an alternative approach in line with a pluralist understanding of epistemic rationality.

In recent years, permissivism—the claim that a body of evidence can rationalize more than one response—has enjoyed somewhat of a revival. But it is once again being threatened, this time by a host of new and interesting arguments that, at their core, are challenging the permissivist to explain why rationality matters. A version of the challenge that I am especially interested in is this: if permissivism is true, why should we expect the rational credences to be more accurate than the (...) irrational ones? My aim is to turn this challenge on its head and argue that, actually, those who deny permissivism will have a harder time responding to such a challenge than those who accept it. (shrink)

We present a minimal pragmatic restriction on the interpretation of the weights in the “Equal Weight View” regarding peer disagreement and show that the view cannot respect it. Based on this result we argue against the view. The restriction is the following one: if an agent, $$\hbox {i}$$ i, assigns an equal or higher weight to another agent, $$\hbox {j}$$ j,, he must be willing—in exchange for a positive and certain payment—to accept an offer to let a completely rational and (...) sympathetic $$\hbox {j}$$ j choose for him whether to accept a bet with positive expected utility. If $$\hbox {i}$$ i assigns a lower weight to $$\hbox {j}$$ j than to himself, he must not be willing to pay any positive price for letting $$\hbox {j}$$ j choose for him. Respecting the constraint entails, we show, that the impact of disagreement on one’s degree of belief is not independent of what the disagreement is discovered to be. (shrink)

The authors argue in favor of the “nonconciliation” (or “steadfast”) position concerning the problem of peer disagreement. Throughout the paper they place heavy emphasis on matters of phenomenology—on how things seem epistemically with respect to the net import of one’s available evidence vis-à-vis the disputed claim p, and on how such phenomenology is affected by the awareness that an interlocutor whom one initially regards as an epistemic peer disagrees with oneself about p. Central to the argument is a nested goal/sub-goal (...) hierarchy that the authors claim is inherent to the structure of epistemically responsible belief-formation: pursuing true beliefs by pursuing beliefs that are objectively likely given one’s total available evidence; pursuing this sub-goal by pursuing beliefs that are likely true (given that evidence) relative to one’s own deep epistemic sensibility; and pursuing this sub-sub-goal by forming beliefs in accordance with one’s own all-in, ultima facie, epistemic seemings. (shrink)

By taking the practical relevance of coordinated epistemic standards into account, Dogramaci and Horowitz (2016) as well as Greco and Hedden (2016) offer a new perspective on epistemic permissiveness. However, in its current state, their argument appears to be inconclusive. I will offer two reasons why this argument does not support interpersonal uniqueness in general. First, such an argument leaves open the possibility that distinct closed societies come to incompatible epistemic standards. Second, some epistemic practices like the promotion of methodological (...) heterogeneity in epistemic communities could be best explained by epistemic permissiveness. (shrink)

Responding to Cappelen and Dever’s claim that there is no distinctive role for perspectivality in epistemology, I argue that facts about the outcomes of one’s own reasoning processes may have a different evidential significance than facts about the outcomes of others’.

Epistemic Permissivists face a special problem about the relationship between our first- and higher-order attitudes. They claim that rationality often permits a range of doxastic responses to the evidence. Given plausible assumptions about the relationship between your first- and higher-order attitudes, it can't be rational to adopt a credence on the edge of that range. But Permissivism says that, for some such range, any credence in that range is rational. Permissivism, in its traditional form, cannot be right. I consider some (...) new ways of developing Permissivism to avoid this argument, but each has problems of its own. (shrink)

Permissivism about rationality is the view that there is sometimes more than one rational response to a given body of evidence. In this paper I discuss the relationship between permissivism, deference to rationality, and peer disagreement. I begin by arguing that—contrary to popular opinion—permissivism supports at least a moderate version of conciliationism. I then formulate a worry for permissivism. I show that, given a plausible principle of rational deference, permissive rationality seems to become unstable and to collapse into unique rationality. (...) I conclude with a formulation of a way out of this problem on behalf of the permissivist. (shrink)

How should one's beliefs be affected by one's knowing that other people, who are equally well-informed, rational, and intelligent – in other words, persons who are epistemic, or intellectual, peers – believe differently? In this thesis I look at a certain answer to this question. Richard Feldman argues that when two persons who have the same level of intelligence and who are equally well-informed disagree, the only rational response is for both persons to give up their disputed beliefs and suspend (...) judgment. I look at two objections to Feldman’s view, one from Ernest Sosa and the other from Thomas Kelly. In the end, I side with Feldman. Feldman’s call for suspension of judgment is based on an observation of symmetry in peer disagreements. Feldman argues that, in a peer disagreement, the participants should realize that for each thing one of them can say in support of his view, the other can say something analogous in support of the other view. This symmetry removes any rational basis to prefer one’s own view. I conclude that neither Sosa’s nor Kelly’s objections introduce any relevant asymmetries that would justify the disputants in a peer disagreement in sticking to their original beliefs. (shrink)

We often get evidence concerning the reliability of our own thinking about some particular matter. This “higher-order evidence” can come from the disagreement of others, or from information about our being subject to the effects of drugs, fatigue, emotional ties, implicit biases, etc. This paper examines some pros and cons of two fairly general models for accommodating higher-order evidence. The one that currently seems most promising also turns out to have the consequence that epistemic akrasia should occur more frequently than (...) is sometimes supposed. But it also helps us see why this might not be a bad thing. (shrink)

The Uniqueness Thesis holds, roughly speaking, that there is a unique rational response to any particular body of evidence. We first sketch some varieties of Uniqueness that appear in the literature. We then discuss some popular views that conflict with Uniqueness and others that require Uniqueness to be true. We then examine some arguments that have been presented in its favor and discuss why permissivists find them unconvincing. Last, we present some purported counterexamples that have been raised against Uniqueness and (...) discuss some possible reasons why proponents of Uniqueness might find these similarly unconvincing. (shrink)

Abstract. Richard Feldman’s Uniqueness Thesis holds that “a body of evidence justifies at most one proposition out of a competing set of proposi- tions”. The opposing position, permissivism, allows distinct rational agents to adopt differing attitudes towards a proposition given the same body of evidence. We assess various motivations that have been offered for Uniqueness, including: concerns about achieving consensus, a strong form of evidentialism, worries about epistemically arbitrary influences on belief, a focus on truth-conduciveness, and consequences for peer disagreement. (...) We argue that each of these motivations either misunderstands the commitments of permissivism or is question-begging. Better understanding permissivism makes it a much more plausible position. (shrink)

Conciliationism faces a challenge that has not been satisfactorily addressed. There are clear cases of epistemically significant merely possible disagreement, but there are also clear cases where merely possible disagreement is epistemically irrelevant. Conciliationists have not yet accounted for this asymmetry. In this paper, we propose that the asymmetry can be explained by positing a selection constraint on all cases of peer disagreement—whether actual or merely possible. If a peer’s opinion was not selected in accordance with the proposed constraint, then (...) it lacks epistemic significance. This allows us to distinguish the epistemically significant cases of merely possible disagreement from the insignificant ones. (shrink)

We defend Uniqueness, the claim that given a body of total evidence, there is a uniquely rational doxastic state that it is rational for one to be in. Epistemic rationality doesn't give you any leeway in forming your beliefs. To this end, we bring in two metaepistemological pictures about the roles played by rational evaluations. Rational evaluative terms serve to guide our practices of deference to the opinions of others, and also to help us formulate contingency plans about what to (...) believe in various situations. We argue that Uniqueness vindicates these two roles for rational evaluations, while Permissivism clashes with them. (shrink)

Epistemologists focus primarily on cases of knowledge, belief, or credence where the evidence which one possesses, or on which one is relying, plays a fundamental role in the epistemic or normative status of one's doxastic state. Recent work in epistemology goes beyond the evidence one possesses to consider the relevance for such statuses of evidence which one does not possess, particularly when there is a sense in which one should have had some evidence. I focus here on Sanford Goldberg's approach (...) ("Should Have Known," Synthese, forthcoming; and "On the Epistemic Significance of Evidence You Should Have Had," Episteme 2016, this issue); but the discussion will interest anyone working on epistemic defeat. (shrink)

This paper presents a new solution to the problem of peer disagreement that distinguishes two principles of rational belief, here called probability and autonomy. When we discover that we disagree with peers, there is one sense in which we rationally ought to suspend belief, and another in which we rationally ought to retain our original belief. In the first sense, we aim to believe what is most probably true according to our total evidence, including testimony from peers and authorities. In (...) the second, we aim to base our beliefs only on objective evidence and argumentation, even if that lowers the probability of their being true. The first principle of rational belief tends to serve the short-term epistemic interests of individuals, while the second tends to serve the long-term epistemic interests of both individuals and groups. The best way to reconcile these principles in cases of peer disagreement is to associate them with two corresponding species of belief, here called perception and opinion. (shrink)

Believing rationally is epistemically valuable, or so we tend to think. It’s something we strive for in our own beliefs, and we criticize others for falling short of it. We theorize about rationality, in part, because we want to be rational. But why? I argue that how we answer this question depends on how permissive our theory of rationality is. Impermissive and extremely permissive views can give good answers; moderately permissive views cannot.

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

The axiological account of deep disagreements is described and defended. This proposal understands this notion in terms of the existential importance of the topic of disagreement. It is argued that this account provides a straightforward explanation for the main features of deep disagreements. This proposal is then compared to the contemporary popular view that deep disagreements are essentially hinge disagreements – i.e. disagreements concerning clashes of one’s hinge commitments, in the sense described by the later Wittgenstein. It is claimed that (...) hinge disagreements are only plausibly deep disagreements insofar as there can be a specific class of hinge commitments that are axiological in nature, thereby lending further support to the axiological account of deep disagreement. (shrink)

Kopec and Titelbaum collect five alleged counterexamples to Uniqueness, the thesis that it is impossible for agents who have the same total evidence to be ideally rational in having different doxastic attitudes toward the same proposition. I argue that four of the alleged counterexamples fail, and that Uniqueness should be slightly modified to accommodate the fifth example.

Several philosophers have recently argued that evolutionary considerations undermine the justification of all objectivist moral beliefs by implying a hypothetical disagreement: had our evolutionary history been different, our moral beliefs would conflict with the moral beliefs of our counterfactual selves. This paper aims at showing that evolutionary considerations do not imply epistemically relevant moral disagreement. In nearby scenarios, evolutionary considerations imply tremendous moral agreement. In remote scenarios, evolutionary considerations do not entail relevant disagreement with our epistemic peers, neither on a (...) narrow nor on a broad conception of peerhood. In conclusion, evolutionary considerations do not reveal epistemically troubling kinds of disagreement. Anti-objectivists need to look elsewhere to fuel their sceptical argument. (shrink)

In recent debates over permissivism and uniqueness—two theses concerning the relationship between evidence and epistemic rationality—some philosophers have claimed that permissivism has an intuitive advantage over uniqueness. I examine the cases alleged to intuitively motivate permissivism and suggest they do not provide prima facie support for permissivism. I conclude by explaining how my discussion bears on whether permissivism can defeat skeptical arguments based on recognized peer disagreement and the historical contingency of our beliefs.

Different people reason differently, which means that sometimes they reach different conclusions from the same evidence. We maintain that this is not only natural, but rational. In this essay we explore the epistemology of that state of affairs. First we will canvass arguments for and against the claim that rational methods of reasoning must always reach the same conclusions from the same evidence. Then we will consider whether the acknowledgment that people have divergent rational reasoning methods should undermine one’s confidence (...) in one’s own reasoning. Finally we will explore how agents who employ distinct yet equally rational methods of reasoning should respond to interactions with the products of each others’ reasoning. We find that the epistemology of multiple reasoning methods has been misunderstood by a number of authors writing on epistemic permissiveness and peer disagreement. (shrink)

Epistemologists have shown increased interest in the epistemic significance of disagreement, and in particular, in whether there is a rational requirement concerning belief revision in the face of peer disagreement. This article examines some of the general issues discussed by epistemologists, and then considers how they may or may not apply to the case of religious disagreement, both within religious traditions and between religious (and non-religious) views.

While many philosophers have agreed that evidence of disagreement is a kind of higher-order evidence, this has not yet resulted in formally precise higher-order approaches to the problem of disagreement. In this paper, we outline a simple formal framework for determining the epistemic significance of a body of higher-order evidence, and use this framework to motivate a novel interpretation of the popular “equal weight view” of peer disagreement—we call it the Variably Equal Weight View (VEW). We show that VEW differs (...) from the standard Split the Difference (SD) interpretation of the equal weight view in almost all cases of peer disagreement, and use our formal framework to explain why SD has seemed attractive but is in fact misguided. A desirable feature of VEW, we argue, is that it gives rise to plausible instances of synergy—an effect whereby the parties to a disagreement should become more (or less) confident in the disputed proposition than any of them were prior to disagreement. Lastly, we show how VEW may be generalized to cases of non-peer disagreement. (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)

We introduce a family of rules for adjusting one's credences in response to learning the credences of others. These rules have a number of desirable features. 1. They yield the posterior credences that would result from updating by standard Bayesian conditionalization on one's peers' reported credences if one's likelihood function takes a particular simple form. 2. In the simplest form, they are symmetric among the agents in the group. 3. They map neatly onto the familiar Condorcet voting results. 4. They (...) preserve shared agreement about independence in a wide range of cases. 5. They commute with conditionalization and with multiple peer updates. Importantly, these rules have a surprising property that we call synergy - peer testimony of credences can provide mutually supporting evidence raising an individual's credence higher than any peer's initial prior report. At first, this may seem to be a strike against them. We argue, however, that synergy is actually a desirable feature and the failure of other updating rules to yield synergy is a strike against them. (shrink)