Default logic has been a very active research topic in artificial intelligence since the early 1980s, but has not received as much attention in the philosophical literature thus far. This paper shows one way in which the technical tools of artificial intelligence can be applied in contemporary epistemology by modeling a paradigmatic case of deep disagreement using default logic. In §1 model-building viewed as a kind of philosophical progress is briefly motivated, while §2 introduces the case of deep disagreement we (...) aim to model. On the heels of this, §3 defines our formal framework, viz., a refined Horty-style default logic. §4 then uses the framework to model deep disagreement, and finally §5 provides a critical discussion of the result. (shrink)

This paper defends a particular view of explaining reasonable disagreement: the Conceptual View. The Conceptual View is the idea that reasonable disagreements are caused by differences in the way reasonable people use concepts in a cognitive process to make moral and political judgements. But, that type of explanation is caught between either an explanatory weakness or an unparsimonious and potentially self-undermining theory of concepts. When faced with deep disagreements, theories on the Conceptual View either do not have the resources to (...) explain them, or can only explain them by committing to a completely new theory of concepts where all moral and political concepts are a unique type of concept. This paper shows how the Conceptual View can avoid this dilemma by adopting what I dub the ‘Metalinguistic Strategy’ for explaining reasonable disagreement. The Metalinguistic Strategy uses recent innovations in the philosophy of language on metalinguistic negotiation to explain reasonable disagreements whether they be ordinary or deep disagreements as genuine disagreements whilst maintaining our ordinary ideas about concepts. (shrink)

ABSTRACTIn his account of public reason Rawls assumes that some facts ought to be treated as ‘fixed’, or beyond reasonable disagreement. These include, for him, facts upon which there is a scientif...

This paper explores the application of hinge epistemology to deep disagreement. Hinge epistemology holds that there is a class of commitments—hinge commitments—which play a fundamental role in the structure of belief and rational evaluation: they are the most basic general ‘presuppositions’ of our world views which make it possible for us to evaluate certain beliefs or doubts as rational. Deep disagreements seem to crucially involve disagreements over such fundamental commitments. In this paper, I consider pessimism about deep disagreement, the thesis (...) that such disagreements are rationally irresolvable, and ask whether the Wittgensteinian account of deep disagreement—according to which such disagreements are disagreements over hinge commitments—provides adequate support for pessimism. I argue that the answer to this question depends on what hinge commitments are and what our epistemic relation to them is supposed to be. I argue for two core claims. First, that non-epistemic theories of hinge commitments provide adequate support for pessimism. Nevertheless, such theories have highly implausible consequences in the context of deep disagreement. Secondly, at least one epistemic theory of hinge commitments, the entitlement theory, permits optimism about such disagreements. As such, while hinge epistemology is mainly pessimistic about deep disagreement, it doesn’t have to be. (shrink)

This paper explores the application of hinge epistemology to deep disagreement. Hinge epistemology holds that there is a class of commitments—hinge commitments—which play a fundamental role in the structure of belief and rational evaluation: they are the most basic general ‘presuppositions’ of our world views which make it possible for us to evaluate certain beliefs or doubts as rational. Deep disagreements seem to crucially involve disagreements over such fundamental commitments. In this paper, I consider pessimism about deep disagreement, the thesis (...) that such disagreements are rationally irresolvable, and ask whether the Wittgensteinian account of deep disagreement—according to which such disagreements are disagreements over hinge commitments—provides adequate support for pessimism. I argue that the answer to this question depends on what hinge commitments are and what our epistemic relation to them is supposed to be. I argue for two core claims. First, that non-epistemic theories of hinge commitments provide adequate support for pessimism. Nevertheless, such theories have highly implausible consequences in the context of deep disagreement. Secondly, at least one epistemic theory of hinge commitments, the entitlement theory, permits optimism about such disagreements. As such, while hinge epistemology is mainly pessimistic about deep disagreement, it doesn’t have to be. (shrink)

Questions surrounding deep disagreement have gained significant attention in recent years. One of the central debates is metaphysical, focusing on the features that make a disagreement deep. Proposals for what makes disagreements deep include theories about hinge propositions and first epistemic principles. In this paper, I criticize this metaphysical discussion by arguing that it is methodologically flawed. Deep disagreement is a technical or semi-technical term, but the metaphysical discussion mistakenly treats it as a common-sense concept to be analyzed and captured (...) by our pre-theoretical intuitions. Since the literature on deep disagreement is subject to this fundamental confusion and deep disagreement is not a helpful umbrella term either, I propose eliminating the notion of deep disagreement from the philosophical discourse. Instead of analyzing the nature of deep disagreement, we should develop theories about different forms of disagreement, including disagreement about hinge propositions and disagreement about epistemic principles, and, in particular, a theory of rationally irresolvable disagreement. (shrink)

The discussion about deep disagreement has gained significant momentum in the last several years. This discussion often relies on the intuition that deep disagreement is, in some sense, rationally irresolvable. In this paper, I will provide a theory of rationally irresolvable disagreement. Such a theory is interesting in its own right, since it conflicts with the view that rational attitudes and procedures are paradigmatic tools for resolving disagreement. Moreover, I will suggest replacing discussions about deep disagreement with an analysis of (...) rationally irresolvable disagreement, since this notion can be more clearly defined than deep disagreement and captures the basic intuitions underlying deep disagreement. I will first motivate this project by critically assessing the current debate about deep disagreement. I then detail the notions of rationality and resolvable disagreement which are crucial for a suitable theory of rationally irresolvable disagreement before sketching various instances of rationally irresolvable disagreement. Finally, I argue for replacing theories of deep disagreement with theories of rationally irresolvable disagreement, an approach that has significant advantages over existing theories of deep disagreement which focus on hinge propositions or fundamental epistemic principles. (shrink)

Sometimes ordinary disagreements become deep as a result of epistemic injustice. The paper explores a hitherto unnoticed connection between two phenomena that have received ample attention in recent social epistemology: deep disagreement and epistemic injustice. When epistemic injustice comes into play in a regular disagreement, this can lead to higher-order disagreement about what counts as evidence concerning the original disagreement, which deepens the disagreement. After considering a common definition of deep disagreement, it is proposed that the depth of disagreements is (...) best understood as a matter of degree. Then, a case study of real-life disagreement is introduced: the disagreement about whether racism is a significant issue in the Netherlands, illustrated by the tradition of ‘Black Pete’. It is argued that there is disagreement about what counts as evidence in the case study because of two forms of epistemic injustice: testimonial and hermeneutical injustice. Specifically, there is disagreement about epistemic principles concerning whether private first-personal experience of racism is a weighty source of evidence in this domain, whether victims of racism count as important testifiers in this domain, and how to assess testimony that is not intelligible to you because it employs concepts and terminology you are unfamiliar with. By dismissing the relevant testimony and epistemic resources, the disagreement boils down to disagreement on the level of epistemic principles concerning,, and. Introducinginjustice-based deep disagreementhighlights moral and political aspects of disagreements that might seem factual. (shrink)

We all agree that democratic decision-making requires a factual input, and most of us assume that when the pertinent facts are not in plain view they should be furnished by well-functioning scientific institutions. But how should liberal democracy respond when apparently sincere, rational and well-informed citizens object to coercive legislation because it is based on what they consider a misguided trust in certain parts of science? Cases are familiar, the most prominent concerning climate science and evolution, but one may also (...) count GMO-skepticism and vaccine-skepticism, and there are plenty of others. The paper defends what I, borrowing an expression from Badiola, call Science as Public Reason, asserting roughly that some policy-relevant factual proposition P is part of public reason if and only if there is consensus about P among scientific experts in the relevant well-functioning scientific institutions. I defend this view against the controversiality objection claiming that scientific findings cannot in this general way pass as public reason as they are sometimes controversial among reasonable citizens. My preferred line of defense is what I call Dogmatism about Science as Public Reason, which roughly amounts to insisting on Science as Public Reason on the ground that it is a philosophically well-motivated view, while conceding that it may not be acceptable to all minimally rational and well-informed individuals. (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)

Although research on epistemic injustice has focused on the effects of prejudice in epistemic exchanges, the account of prejudice that emerges in Fricker’s (2007) view is not completely clear. In particular, I claim that the epistemic role of prejudice in the structure of testimonial justification is still in need of a satisfactory explanation. What special epistemic power does prejudice exercise that prevents the speaker’s words from constituting evidence for the hearer’s belief? By clarifying this point, it will be possible to (...) address two more general issues concerning the nature of prejudice: its resistance to counterevidence and the steps involved in overcoming prejudice. I propose a hinge account of prejudice, based on the recent perspective of hinge epistemology, to help clarify these aspects. According to the hinge account, prejudices share a fundamental feature with hinges: they work as norms of evidential significance, and as such, they determine what can and cannot count as evidence for belief. (shrink)

Interpersonal disagreement happens all the time. How to properly characterize interpersonal disagreement and how to respond to it are important problems, but the existence of such disagreements at least is obvious. The existence of intrapersonal disagreement, however, is another matter. On the one hand, we do change our minds sometimes, especially when new evidence comes in, and so there is a clear enough sense in which we can be characterized as having disagreements with our past selves. But what about synchronic (...) disagreements with ourselves? Are such cases possible, or is there something about the nature of belief that rules out the possibility of knowingly holding beliefs which cannot be rationally held at the same time? In this paper, I argue that there can be cases of intrapersonal synchronic disagreement, and that such disagreements can be deep, in the same way that interpersonal disagreements can be deep. For intrapersonal disagreements, just like interpersonal disagreements, can be grounded in conflicting frameworks for interpreting and reasoning about the world. I also argue that synchronic intrapersonal disagreements are peer disagreements. The paper ends with a discussion of four possible responses to interpersonal deep disagreements, concluding that if those responses are sometimes rational responses in the interpersonal case, then they are also sometimes rational responses in the intrapersonal case. (shrink)

Sometimes we disagree because of fundamental differences in what we treat as reasons for belief. Such are ‘deep disagreements'. Amongst the questions we might ask about deep disagreement is the epistemic normative one: how ought one to respond to disagreement, when that disagreement is deep. This paper addresses that question. According to the position developed, how one ought to respond to deep disagreement depends upon two things: (i) Whether one remains, in the context of disagreement, permitted to trust oneself in (...) following one's epistemic norms and in relation to that (ii) whether one has the shared stock of social-epistemic experiences with followers of one's rival's norms such that one could reasonably be expected to see their way of doing things as a genuine epistemic alternative to one's own. Section 1 introduces a model of deep disagreement such that deep disagreements occur when disputants disagree because they follow different epistemic norms. Section 2 surveys the possible theoretical stances to take towards the epistemic-normative question. Section 3 develops an account of what it is to follow an epistemic norm. Section 4 applies this conception of norm-following to the epistemic-normative question. Section 5 discusses two points of clarification. (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.

The conciliationist and steadfast approaches have dominated the conversation in the epistemology of disagreement. In this paper, drawing on Jennifer Lackey’s justificationist approach and the casuistry paradigm in medical ethics, I will develop a more contextual epistemology of political disagreement. On this account, a given political disagreement’s scope, domain, genealogy, and consequence can be helpful for determining whether we should respond to that disagreement at the level of our confidence, beliefs, or with policy. Though some may argue that responding with (...) policy is a practical consideration instead of an epistemic matter, I argue that even policy responses to disagreements have an epistemic dimension to them that we should not ignore. (shrink)