1 Problems of Disagreement

Disagreements of various kinds pose practical problems that we all have to deal with in our day to day lives. Disagreements can arise on any topic, and they can have varying levels of depth, where depth is a measure of how far down a disagreement goes, or how far we have to go down toward the bedrock of our conceptual systems in order to reach common ground. The ability to properly characterize and responsibly respond to disagreements is an important skill for us to foster, both for ourselves as individuals who want to live well with others, and as citizens who want to live in a pluralistic yet cohesive society. Theoretical problems arise, however, when we try to characterize and formulate criteria for the responsible and rational resolution of various kinds of disagreement.

In 1985, Robert Fogelin argued that deep disagreements—roughly, disagreements that are rooted in conflicting fundamental frameworks of one sort or another—are not susceptible to rational resolution, because framework-level propositions articulate paradigms of judgement; as such, they are epistemically primitive and fundamental, and are entwined together with whole systems of beliefs, values, and practices. Disagreements between subjects who are committed to conflicting or incongruent frameworks, therefore, cannot be distilled down to conflicts over discrete complexes of reasons and claims. Rather, it is only within frameworks—where notions of evidential support, and of what counts as evidence in the first place, are (roughly) delineated—that reasons can have purchase. According to Fogelin, then, “deep disagreements cannot be resolved through the use of argument, for they undercut the conditions essential to arguing” (1985, p. 5). For Fogelin, framework propositions themselves are not properly epistemic—they are not the kind of thing that can be rational or irrational, warranted or unwarranted—but instead comprise the background against which intra-framework claims are judged to be rational or irrational. In normal argumentative contexts, people accept roughly the same frameworks: reasons have a shared, recognizable currency, so argumentation is possible, and rational resolutions of disagreements can be reached. In cases where people accept conflicting frameworks, the necessary conditions for argumentation are absent, and so the “rational” resolution of disagreement is impossible.Footnote 1

Argumentation theorists since Fogelin have grappled with whether rational resolutions are possible in cases of deep disagreement, as well as with what it even means to say that a disagreement is deep. They have also sometimes attempted to address what is to be done in response to deep disagreement, if the conditions for normal argumentation really are absent.Footnote 2

Epistemological work on disagreement has been mostly concerned with what one ought rationally to do in the face of so-called “peer disagreement.”Footnote 3 Those we regard as epistemic peers on some topic are people whom we respect intellectually, and whom we judge to be roughly as capable as we are at accurately forming beliefs on that topic. “Peer disagreement” generally refers to a situation in which it has come to light that we have been exposed to the same body of evidence as has our epistemic peer, and we respond to the evidence by forming one doxastic attitude, while our peer responds by forming a conflicting doxastic attitude.

Epistemologists have wrestled with what one ought rationally to do in such situations (should all parties to the disagreement maintain their original belief? Should they all suspend judgment? Should some maintain their original belief while others should change their minds?), as well as with what it means to call someone an “epistemic peer,” and with whether a true situation of peer disagreement could ever really arise. Other related epistemological questions have to do with how one ought to react to higher-order evidence, and how to formulate principles connecting the rationality of first-order and higher-order belief. (For instance: “if it is rational for S to believe that p is the rational thing for S to believe, then p is the rational thing for S to believe”—this level-connecting principle can seem obvious, but it is controversial).Footnote 4

With a few notable exceptions,Footnote 5 recent work on disagreement has engaged either the epistemological problems and approaches or the argumentation-theoretic problems and approaches, but not both. The aim of this Special Issue is twofold: first, it aims to push research on these topics forward in new and interesting ways; and second, it aims to push this research forward specifically by explicitly bringing epistemological and argumentation-theoretic approaches into contact with each other.

The following section of this Introduction contains a brief overview of the essays contained in this Special Issue. The essays are organized thematically: the essays in Sect. 1 address the problem of how to characterize deep disagreement. Those in Sect. 2 address theoretical issues about knowledge, rationality, and justification. Several of the essays in this section address the potential relativistic implications of deep disagreements, as well as Wittgensteinian hinge epistemology. The essays in Sect. 3 address deep disagreements as they arise in the particular discursive contexts of logic, politics, and religious belief. Those in Sect. 4 address interpersonal and intrapersonal aspects of both deep and peer disagreement.

Our aim in organizing the essays in this way is to draw together and to make explicit some of the central themes and problems addressed by contributors to this Special Issue. Of course many of the essays could fit comfortably in multiple sections; this categorization is by no means exclusive. Still, we hope that it is helpful to the reader to have the essays grouped in this way.

2 Contents

In composing the following overview of the contents of this Special Issue, for the most part we have lightly rewritten the authors’ own abstracts. In some cases we have expanded or revised the authors’ abstracts more significantly.

2.1 What is Deep Disagreement?

1. Paul Simard Smith & Michael Patrick Lynch, “Varieties of Deep Epistemic Disagreement”

Simard Smith and Lynch discuss three different kinds of disagreement that have been, or could reasonably be, characterized as deep disagreements. Principle level disagreements are disagreements over the truth of epistemic principles; sub-principle level deep disagreements are disagreements over how to assign content to schematic norms; and finally, framework-level disagreements are holistic disagreements over meaning rather than truth—that is, over how to understand networks of epistemic concepts and the beliefs that those concepts compose. Simard Smith and Lynch argue that within the context of each of these kinds of disagreement, it is not possible for the parties to the dispute to rationally persuade one another through only offering epistemic reasons for their conflicting points of view. However, in spite of the inability to rationally persuade, Simard Smith and Lynch explore how it may nevertheless be possible to rationally navigate each of these varieties of deep disagreement.

2. Chris Ranalli, “What is Deep Disagreement?”

Ranalli considers two similar albeit seemingly rival answers to the question of the nature of deep disagreement: the Wittgensteinian theory, according to which deep disagreements are disagreements over hinge propositions, and the fundamental epistemic principle theory, according to which deep disagreements are disagreements over fundamental epistemic principles. Ranalli proposes a set of desiderata for a satisfactory theory of deep disagreement: a good theory of deep disagreement ought to explain the persistence and systematicity of deep disagreements, and it ought to be consistent with the disagreement being a genuine disagreement, where the parties to the disagreement take themselves to be providing reasons for their views. Ranalli argues that while the fundamental epistemic principle theory does better than the Wittgensteinian theory at satisfying these desiderata, the fundamental epistemic principle theory nevertheless struggles to explain the variety of deep disagreement.

3. Matthew Shields, “On the Pragmatics of Deep Disagreement”

Shields argues for two conceptual tools that help shed light on deep disagreements and their epistemological consequences. First, he argues that we are best off construing deep disagreements as disagreements over conflicting understandings of certain concepts. In particular, he suggests that deep disagreements are disagreements over how to understand concepts that play what Michael Friedman calls a “constitutive” role for speakers. Second, Shields argues that we need a better understanding of what speakers are doing when they engage in deep disagreements—i.e., what speech acts they are carrying out. He argues that we should not reduce the relevant speech acts to more familiar speech act kinds, such as assertions or imperatives; instead, when a speaker articulates an understanding of a concept, they are in part carrying out an act of stipulation. Shields provides an account of the pragmatics of stipulation, and applies the account to examples of deep disagreement. Importantly, focusing on the stipulative dimension of deep disagreement opens up, in turn, a novel approach to defusing the epistemological challenges such disagreement seems to pose.

4. Scott F. Aikin, “Deep Disagreement and the Problem of the Criterion”

In this paper, Aikin compares two philosophical problems, the problem of the criterion and the problem of deep disagreement, and notes a core similarity which explains why many proposed solutions to these problems seem to fail along similar lines. In particular, regarding the problem of the criterion, some philosophers propose that we suspend the “backing requirement” when it comes to some propositions (e.g., when it comes to particular items of knowledge, or to general epistemic principles); regarding deep disagreements, a parallel solution is to give up the “dialecticality requirement,” which is the requirement that arguments must be dialectically appropriate for their audiences. Aikin argues that the dialecticality requirement issues from the requirement that we respect each other’s intellectual autonomy, and so we should not suspend that requirement. Aikin proposes a kind of skeptical solution to the problem of deep disagreement, and this skeptical program has consequences for the problem as it manifests in political epistemology and metaphilosophy.

2.2 Theoretical Issues

2.2.1 Epistemic Concerns

5. Jonathan Matheson, “Deep Disagreements and Rational Resolution”

This paper brings together work on disagreement in both epistemology and argumentation theory, and explores how some views pertaining to deep disagreements in argumentation theory can act as an objection to a prominent view of the epistemology of disagreement, the Equal Weight View. Matheson shows how the Equal Weight View entails that deep disagreements between epistemic peers are rationally resolvable; he then examines a challenge to the Equal Weight View according to which this consequence is untenable; and he argues that there is a viable response to make on behalf of the Equal Weight View.

6. Klemens Kappel, “Higher Order Evidence and Deep Disagreement”

Deep disagreements can be broadly characterized as cases where local disagreements are intertwined with more general basic disagreements about the relevant evidence, standards of argument, or proper methods of inquiry in that domain. In this paper, Kappel 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 how to respond to disagreements, arguing 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. Applying this view to deep disagreement, we get the result 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. Kappel argues that this gives a better general view of deep disagreement than views appealing to epistemic peers, personal information, or independence.

7. Catherine E. Hundleby, “Epistemic Coverage and Argument Closure”


In this paper, Hundleby draws together the parallel views of Sanford Goldberg, in epistemology, and Doug Walton, in argumentation theory. Hundleby argues that Goldberg’s account of epistemic coverage (roughly: if p were true, then I would have heard about it by now) constitutes a special case of Walton’s account of epistemic closure (roughly, his account of the dialectical norms for legitimately ending an argument with a claim to knowledge). In Walton’s framework, epistemic coverage operates at the limits of argument closure because it minimizes dialectical exchange. Such closure works together with a shared hypothetical consideration to justify dismissal of surprising claims.


8. Mariangela Zoe Cocchiaro & Bryan Frances, “Epistemically Different Epistemic Peers”


For over a decade now epistemologists have been thinking about the peer disagreement problem of whether a person is reasonable in not lowering her confidence in her belief, p, when she comes to accept that she has an epistemic peer on p who disbelieves p. However, Cocchiaro and Frances argue, epistemologists have overlooked a key realistic way how epistemic peers can, or even have to, differ epistemically—a way that reveals the inadequacy of both conformist and non-conformist views on peer disagreement by uncovering how the causes of peer disagreement bear on the debate’s core philosophical issue. Part of their argument for this thesis involves giving a thorough yet entirely informal presentation of well-known theorems in economics, which represent a formally precise description of how two rational agents must deal with disagreement under certain epistemically interesting circumstances.

2.2.2 Deep Disagreement and Relativism

9. J. Adam Carter, “Archimedean Metanorms”

In this paper, Carter addresses the “non-neutrality” argument for epistemic relativism. The argument is that, in certain dialectical contexts—such as the famous dispute between Galileo and Cardinal Bellarmine concerning geocentrism—it seems as though a lack of suitably neutral epistemic standards that either side could appeal to in order to (non-question-beggingly) resolve their first-order dispute is itself evidence for epistemic relativism. Carter proceeds by unpacking and charitably reformulating the non-neutrality argument, so that it appeals not only to the availability of epistemic norms that are suitably neutral between interlocutors, but also to the availability of what Carter calls “Archimedean metanorms.” With the argument charitably developed in this way, Carter argues that even though it avoids problems that face more straightforward “non-neutrality” versions of the argument, it nonetheless runs into various other problems that appear ultimately intractable. Further, Carter argues that the strategy in question gives us no decisive reason to draw the relativist’s conclusion that the parties to the disagreement are equally justified in their beliefs, rather than the Pyrrhonian sceptic’s conclusion that the parties ought to suspend judgment on the topic of the disagreement.

10. Victoria Lavorerio, “Do Deep Disagreements Motivate Relativism?”

In “Motivations for Relativism as a Solution to Disagreements,” Steven Hales argues that relativism is a plausible disagreement resolution strategy for epistemically irresolvable disagreements. Lavorerio responds in this essay, arguing that Hales’s relativistic strategy is not adequate for disagreements of this kind, because it demands an impossible doxastic state for disputants to resolve the disagreement. Contrarily, Robert Fogelin’s theory of deep disagreement does not run into the same problems. Deep disagreements, according to Fogelin, cannot be resolved through argumentation because the conditions for argumentation are lacking in such contexts. Lavorerio argues that deep disagreements arise due to differences in disputants’ mutually supporting interrelated beliefs. This view avoids the hurdles caused by the tiered structure of support found at the heart of Hales’s view on disagreement: the assumption that belief and perspective can be separated, and that disagreement is located in the latter.

11. Martin Kusch, “Disagreement, Certainties, Relativism”

This paper seeks to widen the dialogue between the “epistemology of peer disagreement” and the epistemology informed by Wittgenstein’s last notebooks, later edited as On Certainty. Kusch defends the following theses: (i) not all certainties are groundless; many of them are beliefs; and they do not have a common essence. (ii) An epistemic peer need not share all of one’s certainties. (iii) Which response (steadfast, conciliationist, etc.) to a disagreement over a certainty is called for depends on the type of certainty in question. Sometimes a form of relativism is the right response. (iv) Reasonable, mutually recognized peer disagreement over a certainty is possible. The paper thus addresses both interpretative and systematic issues, using Wittgenstein as a resource for thinking about peer disagreement over certainties.

2.2.3 Wittgenstein and Hinge Propositions

12. Harvey Siegel, “Hinges, Disagreements, and Arguments: (Rationally) Believing Hinge Propositions and Arguing across Deep Disagreements”

Wittgenstein famously introduced the notion of “hinge propositions”: propositions that are assumptions or presuppositions of our languages, conceptual schemes, and language games, presuppositions that cannot themselves be rationally established, defended, or challenged. This idea has given rise to an epistemological approach, “hinge epistemology,” which itself has important (negative) implications for argumentation. In particular, it develops and provides support for Robert Fogelin’s case for deep disagreements: disagreements that cannot be rationally resolved by processes of rational argumentation. In this paper, Siegel examines hinge epistemology in its own right, and explores its implications for arguments and the theory of argumentation. Siegel argues that (1) the Wittgensteinian approach to hinge propositions is problematic, and that, suitably understood, hinges can be rationally challenged, defended, and evaluated; (2) there are no well-formed, coherent propositions, “hinge” or otherwise, that are beyond epistemic evaluation, critical scrutiny, and argumentative support/critique; and (3) good arguments concerning hinge propositions are not only possible but common. Siegel’s arguments rely on a thoroughgoing fallibilism, a rejection of “privileged” frameworks, and an insistence on the challengeability of all frameworks, both from within and from without.

13. Duncan Pritchard, “Wittgensteinian Hinge Epistemology and Deep Disagreement”

Deep disagreements concern our most basic and fundamental commitments. Such disagreements seem to be problematic because they appear to manifest epistemic incommensurability in our epistemic systems, and thereby lead to epistemic relativism. Pritchard confronts this problem via consideration of a Wittgensteinian hinge epistemology. On the face of it, this Wittgensteinian proposal exacerbates the problem of deep disagreements by granting that our most fundamental commitments are essentially arationally held. Pritchard argues, however, that a hinge epistemology, properly understood, does not licence epistemic incommensurability or epistemic relativism at all. On the contrary, such an epistemology in fact shows us how to rationally respond to deep disagreements. Pritchard claims that if we can resist the problematic relativistic consequences even from the perspective of a hinge epistemology, then we should be very suspicious of the idea that deep disagreements in general are as epistemologically problematic as has been widely supposed.

2.3 Special Discursive Contexts

2.3.1 Meta-Logical Disagreements

14. Ben Martin, “Searching for Deep Disagreement in Logic: The Case of Dialetheism”

According to Fogelin’s account of deep disagreements, disputes caused by a clash in framework propositions are necessarily rationally irresolvable. Fogelin’s thesis is a claim about real-life, and not purely hypothetical, arguments: there are such disagreements, and they are incapable of rational resolution. Surprisingly then, few attempts have been made to find such disputes in order to test Fogelin’s thesis. In this paper, Martin aims to rectify that failure. Firstly, Martin clarifies Fogelin’s concept of deep disagreement and shows there are several different breeds of such disagreements. Thus, to fully assess Fogelin’s thesis, it is necessary to seek out cases of each breed to evaluate their rational irresolvability. The paper then begins this task by looking at a significant debate within the logical literature over the truth of contradictions. Martin argues that, while the debate exemplifies a breed of deep disagreement, the parties involved can supply one another with rationally compelling reasons.

2.3.2 Religious Disagreement

15. Frederick Choo, “The Epistemic Significance of Religious Disagreements: Cases of Unconfirmed Superiority Disagreements”

Religious disagreements are widespread. Some philosophers have argued that religious disagreements call for religious skepticism, or a revision of one’s religious beliefs. In order to figure out the epistemic significance of religious disagreements, two questions need to be answered. First, what kind of disagreements are religious disagreements? Second, how should one respond to such disagreements? In this paper, Choo argues that many religious disagreements are cases of unconfirmed superiority disagreements, where parties have good reason to think they are not epistemic peers, yet they lack good reason to determine who is superior. Such disagreements have been left relatively unexplored in the literature. Choo then argues that in cases of unconfirmed superiority disagreements, disputants can remain relatively steadfast in holding to their beliefs. Hence, we can remain relatively steadfast in our beliefs in such cases of religious disagreements.


16. James Kraft, “Incommensurability and Wide‑Ranging Arguments for Steadfastness in Religious Disagreements: Increasingly Popular, But Eventually Complacent”


Frederick Choo and John Pittard recently have presented new attractive incommensurability arguments for remaining steadfast in religious beliefs even when disagreeing with sophisticated disputants. This article responds to the latest iteration of this genre in the work of Choo, and does double duty evaluating more generally the merits of this genre, which is becoming increasingly more popular since originally championed by William Alston. Both Choo and Alston argue that it is reasonable to stay steadfast in one’s religious beliefs when there are no commensurable ways of evaluating the disputant’s claims. This paper first describes four views about disagreement that inform Choo’s conclusion, one of which is the incommensurability argument similarly championed by Alston. Kraft argues that incommensurability arguments are attractive, but, when deployed in the most challenging disagreements, ultimately complacent.

2.3.3 Political Discourse


17. Jay Carlson, “Epistemology of Disagreement, Bias, and Political Deliberation: The Problems for a Conciliatory Democracy”


In this paper, Carlson discusses the relevance of the epistemology of disagreement to political disagreement. The two major positions in the epistemology of disagreement literature are the steadfast and the conciliationist approaches: while the conciliationist says that disagreement with one’s epistemic equals should compel one to epistemically “split the difference” with those peers, the steadfast approach claims that one can maintain one’s antecedent position even in the face of such peer disagreement. Martin Ebeling has applied a conciliationist approach to democratic deliberations, arguing that deliberative participants ought to pursue full epistemic conciliation when disagreeing with their peers on political questions. Carlson responds to Ebeling’s view, arguing that an epistemic “splitting the difference” could make participants vulnerable to certain cognitive biases. Carlson suggests that we might avoid these biases by paying more attention to the deliberative environment in which disagreement takes place.

2.4 Personal and Interpersonal Considerations


18. Michael H. G. Hoffmann, “Consensus Building and Its Epistemic Conditions”


Most of the epistemological debate on disagreement tries to develop standards that describe which actions or beliefs would be rational under specific circumstances in a controversy. To build things on a firm foundation, much work starts from certain idealizations—for example, the assumption that parties in a disagreement share all the evidence that is relevant and are equal with regard to their abilities and dispositions. By contrast, Hoffmann focuses in this essay on a different question and takes a different route. The question is: What should people actually do who find themselves in deep disagreement with others? And instead of building theory on some “firm foundation,” the paper starts from a specific goal—building consensus by creating new proposals—and asks, first, which actions are suitable to achieve this goal and, second, what are the epistemic conditions of these actions. With regard to the latter, the paper focuses on what has been called framing and reframing in conflict research, and argues that both metaphors need and deserve a suitable epistemological conceptualization.


19. Moira Kloster, “Another Dimension to Deep Disagreements: Trust in Argumentation”


It has typically been assumed that affective and social components of disagreement, such as trust and fair treatment, can be handled separately from substantive components, such as beliefs and logical principles. This has freed us to count as “deep” disagreements only those which persist even between people who have no animosity towards each other, feel equal to one another, and are willing to argue indefinitely in search of truth. In this essay, Kloster argues that a reliance on such ideal participants diverts us from the question of whether we have swept away the opportunity for some real arguers to have their voices heard, and for those voices to determine the real substance of the disagreement. If affective and social issues need to be assessed side by side with belief differences and reasoning paradigms, investigating trust may assist us to understand and make progress on the affective and social components that are involved in disagreement.


20. Andrew Aberdein, “Courageous Arguments and Deep Disagreements”


Deep disagreements are characteristically resistant to rational resolution. In this paper, Aberdein explores the contribution a virtue-theoretic approach to argumentation can make towards settling the practical matter of what to do when confronted with apparent deep disagreement, with particular attention to the virtue of courage. Aberdein provides a topographical analogy in clarifying the kind of depth involved in deep disagreements; he carefully develops a conception of argumentative courage as a kind of moral courage; and he argues that argumentative courage can promote mutually acceptable resolutions in cases of deep disagreements.


21. Marc‑Kevin Daoust, “Peer Disagreement and the Bridge Principle”


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, Daoust challenge that claim, arguing that, at least in cases of rational disagreement under full disclosure (i.e., the cases in which epistemic peers are fully aware of each other’s evidence and arguments), 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, Daoust argues that there is a necessary connection (or a “bridge”) between interpersonal permissiveness and its intrapersonal counterpart, and that a plausible principle of correct argumentation supports such a bridge.


22. Patrick Bondy, “Deeply Disagreeing with Myself: Synchronic Intrapersonal Deep Disagreements”


Interpersonal disagreement happens all the time. How to properly characterize interpersonal disagreement and how to respond to it are important problems, but the fact that such disagreements exist 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, Bondy argues 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. Bondy also argues 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.