This book presents an original discussion and analysis of epistemic peer disagreement. It reviews a wide range of cases from the literature, and extends the definition of epistemic peerhood with respect to the current one, to account for the actual variability found in real-world examples. The book offers a number of arguments supporting the variability in the nature and in the range of disagreements, and outlines the main benefits of disagreement among peers i.e. what the author calls the benefits to (...) inquiry argument. (shrink)

Higher-order evidence appears to have the ability to defeat rational belief. It is not obvious, however, why exactly the defeat happens. In this paper, I consider two competing explanations of higher-order defeat: the “Objective Higher-Order Defeat Explanation” and the “Subjective Higher-Order Defat Explanation.” According to the former explanation, possessing sufficiently strong higher-order evidence to indicate that one’s belief about p fails to be rational is necessary and sufficient for defeating one’s belief about p. I argue that this type of explanation (...) is defective or at best collapses into the other type of explanation. According to the latter explanation, Believing that one’s belief about p fails to be rational (in response to higher-order evidence about p) is necessary and sufficient for defeating one’s belief about p. I argue that this type of explanation is better suited to explain higher-order defeat given that what one is rational to believe partly depends on the relations among one’s doxastic attitudes. Finally, I address an peculiar feature of the Subjective Higher-Order Defeat Explanation: higher-order defeat becomes contingent on one’s response to the higher-order evidence. (shrink)

Disagreement and debunking arguments threaten religious belief. In this paper, I draw attention to two types of propositions and show how they reveal new ways to respond to debunking arguments and disagreement. The first type of proposition is the epistemically self-promoting proposition, which, when justifiedly believed, gives one a reason to think that one reliably believes it. Such a proposition plays a key role in my argument that some religious believers can permissibly wield an epistemically circular argument in response to (...) certain debunking arguments. The second type of proposition is the epistemically others-demoting proposition, which, when justifiedly believed, gives one a reason to think that others are unreliable with respect to it. Such a proposition plays a key role in my argument that some religious believers can permissibly wield a question-begging argument to respond to certain types of disagreement. (shrink)

This paper sketches a general account of how to respond in an epistemically rational way to moral disagreement. Roughly, the account states that when two parties, A and B, disagree as to whether p, A says p while B says not-p, this is higher-order evidence that A has made a cognitive error on the first-order level of reasoning in coming to believe that p. If such higher-order evidence is not defeated, then one rationally ought to reduce one’s confidence with respect (...) to the proposition in question. We term this the higher-order evidence account, and present it as a superior to what we might call standard conciliationism, which holds that when agents A and B disagree about p, and are epistemic peers, they should both suspend judgement about p or adjust their confidence towards the mean of A and B’s prior credences in p. Many have suspected that standard conciliationism is implausible and may have skeptical implications. After presenting the HOE account, we put it to work by applying it to a range of cases of moral disagreement, including those that have feature in recent debates assuming standard conciliationism. We show that the HOE account support reasonable, non-skeptical verdicts in a range of cases. Note that this is a paper on moral disagreement, not on the HOE account, thus the account is merely stated here, while defended more fully elsewhere. (shrink)

In any domain of inductive reasoning, we must take care to distinguish between (i) which hypothesis my evidence supports, and (ii) the level of confidence I should have in the hypothesis, given my evidence. This distinction can help resolve the problem of peer demotion, a central point of contention in the epistemology of peer disagreement. It is true that disagreement does not provide evidence that I am right and you are wrong. But it need not, in order to lead to (...) peer demotion: instead, significant disagreement can erode my confidence in the initial peer assessment to a point where I can no longer rationally sustain the belief that we are equally reliable. One consequence of this solution is that the line dividing the Equal Weight view from its competitors emerges as an artifact of a mistakenly one-dimensional picture of the epistemic significance of peer disagreement. (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)

This article examines the central epistemological issues tied to the recognition of disagreement.

This thesis is a collection of three self-contained papers on related themes in the area of formal and social epistemology. The first paper explores the possibility of measuring the coherence of a set with multiplicative averaging. It has been pointed out that all the existing probabilistic measures of coherence are flawed for taking the relevance between a set of propositions as the primary factor which determines the coherence of the set. What I show in this paper is that a group (...) of measures, namely the confirmation-based ones, can be saved from this problem if we adopt a nonlinear averaging function to measure the coherence of a set. The second paper discusses how people should conciliate in disagreements. Some epistemologists take linear averaging as the only way of conciliating and claim that conciliating leads to fallacious results. In the paper, I show that the problem is not conciliating, but taking linear averaging as the only way to conciliate. Since there is no reason for us to insist on conciliating with linear averaging, we can adopt nonlinear averaging functions for conciliating and thereby avoid the formal deficiencies. The third paper focuses on the pragmatic results of taking conciliating as a general strategy in disagreements. There is a potential dilemma about conciliating: if everyone always conciliates, it is likely for an epistemic bubble to arise. If everyone refuses to conciliate, an epistemic echo chamber may appear. A possible way of solving the dilemma is to develop a diachronic strategy which tells people how to both conciliate and update their estimate of their interlocutors’ reliability. Although the three papers differ in the subject, they jointly offer some unifying reflections on the way we approach philosophical problems with formal tools. From 5 the first two papers, we see that a formal analysis of a philosophical position is incomplete if philosophers fail to consider a sufficiently wide range of formal tools. The third paper, on the contrary, shows that we should change the ordinary way of modelling a notion if required. This thesis concludes by proposing a pluralistic view of formal methods in formal epistemology. (shrink)