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)

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

Permissivism says that for some propositions and bodies of evidence, there is more than one rationally permissible doxastic attitude that can be taken towards that proposition given the evidence. Some critics of this view argue that it condones, as rationally acceptable, sets of attitudes that manifest an untenable kind of arbitrariness. I begin by providing a new and more detailed explication of what this alleged arbitrariness consists in. I then explain why Miriam Schoenfield’s prima facie promising attempt to answer the (...) Arbitrariness Objection, by appealing to the role of epistemic standards in rational belief formation, fails to resolve the problem. Schoenfield’s strategy is, however, a useful one, and I go on to explain how an alternative form of the standards-based approach to Permissivism – one that emphasizes the significance of the relationship between people’s cognitive abilities and the epistemic standards that they employ – can respond to the arbitrariness objection. (shrink)

This paper discusses the Uniqueness Thesis, a core thesis in the epistemology of disagreement. After presenting uniqueness and clarifying relevant terms, a novel counterexample to the thesis will be introduced. This counterexample involves logical disagreement. Several objections to the counterexample are then considered, and it is argued that the best responses to the counterexample all undermine the initial motivation for uniqueness.

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)

The Uniqueness thesis says that any body of evidence E uniquely determines which doxastic attitude is rationally permissible regarding some proposition P. Permissivists deny Uniqueness. They are charged with arbitrarily favouring one doxastic attitude out of the set of attitudes they regard as rationally permissible. Simpson claims that an appeal to differences in cognitive abilities can remove the arbitrariness. I argue that it can't. Impermissivists face a challenge of their own: The problem of fine distinctions. I suggest that meeting this (...) challenge requires impermissivists to loosen up at higher levels – when comparing belief-forming systems that differ in the fineness of their doxastic outputs. This more relaxed take on Uniqueness is a kind of ‘intraspecies impermissivism’. (shrink)

The purpose of this paper is to explore the connection between expressivism and disagreement. More in particular, the aim is to defend that one of the desiderata that can be derived from the study of disagreement, the explanation of ‘crossed disagreements’, can only be accommodated within a semantic theory that respects, at the meta-semantic level, certain expressivistic restrictions. We will compare contemporary dynamic expressivism with three different varieties of contextualist strategies to accommodate the specificities of evaluative language –indexical contextualism – (...) truth-conditional pragmatics –, pragmatic strategies using implicatures, and presuppositional accounts. Our conclusion will be that certain assumptions of expressivism are necessary in order to provide a semantic account of evaluative uses of language that can allow us to detect and prevent crossed disagreements. (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)

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 (and likewise for B with respect to not-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 (the HOE 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 (known) 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)

Reductive Evidentialism seeks to explain away all structural requirements of rationality – including norms of logical coherence – in terms of substantive norms of rationality, i.e., responsiveness to evidence. While this view constitutes a novel take on the source of the normativity of logic, I argue that it faces serious difficulties. My argument, in a nutshell, is that, on the assumption that individuals with the same evidence can have different rational responses (interpersonal permissivism), the view lacks the resources to maintain (...) its central tenant that an individual’s body of evidence cannot make it rationally permissible for the individual to believe logical inconsistencies (intrapersonal non-permissivism). (shrink)

In this paper, I explore how the ideal rationality-based account of propositional justification impacts our understanding of the relation between propositional and doxastic justification. The ideal rationality-based account sits uncomfortably with the widely accepted claim that propositional justification is necessary for doxastic justification. In particular, the combination of the necessity claim and the ideal rationality-based account of propositional justification entails that some plausible doxastic attitudes are doxastically unjustified and thereby severs epistemic justification from connections with epistemic responsibility and the competent (...) formation of beliefs. Thus, those who endorse both the necessity claim and the ideal rationality-based account of propositional justification will be forced to give up either their account of propositional justification or the necessity claim. I argue that there is good reason to give up the ideal rationality-based account of propositional justification instead of the necessity claim. This result indicates that an adequate account of propositional justification should be sensitive to the agent’s cognitive capacities. If propositional justification should be understood in this way, then the widely accepted explanation of doxastic justification in terms of propositional justification is not promising either. This is because an agent’s cognitive capacities and limitations play a prominent role in understanding propositional justification. Instead, I argue that, at the explanatory level, propositional justification relies on doxastic justification. (shrink)

The Uniqueness Thesis (U), according to Richard Feldman and Roger White, says that for a given set of evidence E and a proposition P, only one doxastic attitude about P is rational given E. Luis Rosa has recently provided two counterexamples against U which are supposed to show that even if there is a sense in which choosing between two doxastic attitudes is arbitrary, both options are equally and maximally rational. Both counterexamples work by exploiting the idea that ‘ought implies (...) can’ and trying to spell out situations in which some inferences are beyond the capabilities of some reasoners. I argue that on a descriptive account of doxastic rationality, questions of whether ‘epistemic ought implies can’ can be bracketed and that at least one of the inferential moves that Rosa describes in his cases is irrational. I further argue that a descriptive account of doxastic rationality is the appropriate notion of rationality that is to be considered when evaluating U. If my argument for a descriptive account of rationality is successful, then we have reason to revise our use of the term rationality to fit this descriptive understanding. (shrink)

Recently, self-fulfilling cases, that is, ones in which an agent's believing a proposition guarantees its truth, have been offered as counterexamples to uniqueness. According to uniqueness, at most one doxastic attitude is epistemically rational given the evidence. I argue that self-fulfilling cases are not counterexamples to uniqueness because belief-formation is not governed by epistemic rationality in such cases. Specifically, this is because epistemic rationality is not just about forming true beliefs, but about tracking mind-independent truths. In support of the latter (...) claim, I offer three arguments, namely that self-fulfilling and non-self-fulfilling cases differ in their phenomenology, in the norms that guide belief formation, and in the way they relate to the evidence. (shrink)

The paper presents a new argument for epistemic permissivism. The version of permissivism that we defend is a moderate version that applies only to explicit doxastic attitudes. Drawing on Yalcin’s framework for modeling such attitudes, we argue that two fully rational subjects who share all their evidence, prior beliefs, and epistemic standards may still differ in the explicit doxastic attitudes that they adopt. This can happen because two such subjects may be sensitive to different questions. Thus, differing intellectual interests can (...) yield failures of uniqueness. This is not a merely pragmatic phenomenon. (shrink)

Ethics committees like Institutional Review Boards and Research Ethics Committees are typically empowered to approve or reject proposed studies, typically conditional on certain conditions or revisions being met. While some have argued this power should be primarily a function of applying clear, codified requirements, most institutions and legal regimes allow discretion for IRBs to ethically evaluate studies, such as to ensure a favourable risk-benefit ratio, fair subject selection, adequate informed consent, and so forth. As a result, ethics committees typically make (...) moral demands on researchers: require them to act in a way the committee considers ethically right or appropriate. This paper argues that moral demands are legitimate only if publicly justifiable; and as a result, committee decisions are subject to a public justification requirement. Ethics committees can permissibly request for more information, changes to the research protocol or that the research is delayed or even stopped only if these demands are publicly justifiable. This latter claim is in turn justified on the basis that moral demands to φ are permissible only if we are in a position to know that the addressee ought to φ and that we are in a position to know a proposition only if it is publicly justifiable. This argument suggests that ethics committees must consciously and explicitly appeal to public reasons in their decision-making. In cases where public reasons cannot be offered, committees would not be permitted to reject a given study or make approval conditional on an amendment. (shrink)

Morality is intrapersonally permissive: cases abound in which an agent has more than one morally permitted option. In contrast, there is a dearth of cases in which an agent has more than one epistemically permitted response to her evidence. Given the structural parallels between morality and epistemology, why do sources of moral permissiveness fail to have parallel permissive effects in the epistemic domain? This asymmetry between morality and epistemology cries out for explanation. The paper's task is to offer an answer (...) to that call. We explain the asymmetry by tracing moral permissiveness to two factors to which rationality is morally but not epistemically sensitive. (shrink)

Abstract‘Reductive Evidentialism’ seeks to explain away all ‘structural’ requirements of rationality—including norms of logical coherence—in terms of ‘substantive’ norms of rationality, i.e., responsiveness to evidence. While this view constitutes a novel take on the source of the normativity of logic, I argue that it faces serious difficulties. My argument, in a nutshell, is that on the assumption that individuals with the same evidence can have different rational responses (interpersonal permissivism), the view lacks the resources to maintain its central tenet that (...) an individual’s body of evidence cannot make it rationally permissible for the individual to believe logical inconsistencies (intrapersonal nonpermissivism). (shrink)

This work investigates intuitions' nature, demonstrating how philosophers can best use them in epistemology. First, the author considers several paradigmatic thought experiments in epistemology that depict the appeal to intuition. He then argues that the nature of thought experiment-generated intuitions is not best explained by an a priori Platonism. Second, the book instead develops and argues for a thin conception of epistemic intuitions. The account maintains that intuition is neither a priori nor a posteriori but multi-dimensional. It is an intentional (...) but non-propositional mental state that is also non-conceptual and non-phenomenal in nature. Moreover, this state is individuated by its progenitor, namely, the relevant thought experiment. Third, the author provides an argument for the evidential status of intuitions based on the correct account of the nature of epistemic intuition. The suggestion is the fitting-ness approach: intuition alone has no epistemic status. Rather, intuition has evidentiary value as long as it fits well with other pieces into a whole, namely, the pertinent thought experiment. Finally, the book addresses the key challenges raised by supporters of anti-centrality, according to which philosophers do not regard intuition as central evidence in philosophy. To that end, the author responds to them, showing that they fail to affect the account of intuition developed in this book. This text appeals to students and researchers working in epistemology. (shrink)