I investigate the implication of the truth-relativist’s alleged ‘ faultless disagreements’ for issues in the epistemology of disagreement. A conclusion I draw is that the type of disagreement the truth-relativist claims to preserve fails in principle to be epistemically significant in the way we should expect disagreements to be in social-epistemic practice. In particular, the fact of faultless disagreement fails to ever play the epistemically significant role of making doxastic revision rationally required for either party in a disagreement. (...) That the truth-relativists’ disagreements over centred content fail to play this epistemically significant role that disagreements characteristically play in social epistemology should leave us sceptical that disagreement is what the truth-relativist has actually preserved. (shrink)

If we focus on current debates on how creatures revise or correct their beliefs, we can identify two opposing approaches that we propose to call “intellectualism” and “minimalism.” In this paper, we outline a new account of doxastic revision — “the first-order model”— that is neither as cognitively demanding as intellectualism nor as deflationary as minimalism. First-order doxastic revision, we argue, is a personal-level process in which a creature rejects some beliefs and accepts others based on (...) reasons. However, it does not involve second-order thinking or sophisticated semantic and epistemic concepts. Besides defending that there is conceptual space for this alternative, we explore the possibility of extending it to some non-human animals. Based on our interpretation of some empirical evidence, we conclude that there are initial reasons to think that some animals — i.e., great apes— might be able to correct their beliefs in the way that our first-order model suggests. (shrink)

In 1985 Alchourrón, Gärdenfors and Makinson presented their now classic theory of theory change . In 1988 Adam Grove, generalizing David Lewis's theory of counterfactuals, presented a model theory suitable for the AGM theory. Although AGM and Grove mentioned object languages, neither used them. But recently, Maarten de Rijke has shown how object languages can be brought into the picture. In the present paper we take de Rijke's idea further, addressing the question whether there is a particular doxastic or (...) epistemic logic implicit in AGM. (shrink)

In this paper we present a new modeling for belief revision that is what we term irrevocable. This modeling is of philosophical interest since it captures some features of suppositional reasoning, and of formal interest since it is closely connected with AGM, yet provides for iterated belief revision. The analysis is couched in terms of dynamic doxastic logic.

There are different varieties of conservatism concerning belief formation and revision. We assesses the veritistic effects of a particular kind of conservatism commonly attributed to Quine: the so-called maxim of minimum mutiliation, which states that agents should give up as few beliefs as possible when facing recalcitrant evidence. Based on a formal bounded rationality model of belief revision, which parametrizes degree of conservatism, and corresponding multi-agent simulations, we eventually argue against doxastic conservatism from the vantage point of (...) veritistic social epistemology. (shrink)

According to an orthodox account of the relationship between propositional and doxastic justification, basing one’s belief in P on one’s source of propositional justification to believe P suffices for having a doxastically justified belief. But in an increasingly recognized work Turri argues that this thesis fails and proposes a new view according to which having propositional justification depends on having the ability to acquire doxastic justification. Turri’s novel position has surprisingly far-reaching epistemological consequences, ruling out some common epistemological (...) positions that afford one propositional justification in the absence of an ability to acquire doxastic justification. In what follows I show Turri’s novel position to be problematic and go on to suggest a more modest revision to orthodoxy. The first section presents the orthodox view of the relationship between propositional and doxastic justification and Turri’s counterexample to it. The second section introduces Turri’s novel view of that relationship and draws out some of its epistemological implications. The third section gives counterexamples to Turri’s proposal. The fourth section defends a modest revision to orthodoxy. (shrink)

We are consumers of drugs and news, and sometimes call ourselves addicts or junkies of one or both. I propose to take the concept of news – more generally, doxastic – addiction seriously. I define doxastic addiction and relate this type of addiction to echo chambers and religious belief. I show how this analysis directs attention to appropriate interventions to help doxastic addicts, and how it offers a new type of justification for limits on free speech. -/- (...) . (shrink)

Whether responsibility for actions and omissions requires the ability to do otherwise is an important issue in contemporary philosophy. However, a closely related but distinct issue, namely whether doxastic responsibility requires the ability to believe otherwise, has been largely neglected. This paper fills this remarkable lacuna by providing a defence of the thesis that doxastic responsibility entails the ability to believe otherwise. On the one hand, it is argued that the fact that unavoidability is normally an excuse counts (...) in favour of this thesis. On the other hand, three objections against this thesis are discussed and criticized. First, one might think that what suffices for doxastic responsibility is control over or influence on certain desirable or undesirable properties of beliefs. It is argued that this objection misrepresents the issue under consideration. Second, it may be objected that the thesis is contradicted by our intuitions in doxastic analogues of Frankfurt-style scenarios. It is argued that distinguishing between belief-universals and belief-particulars helps to see why this argument fails. Third and finally, one might draw an analogy with the asymmetry thesis in ethics by arguing that even if blameworthy belief requires the ability to believe otherwise, praiseworthy belief does not. It is argued that the main arguments in favour of this presumed asymmetry are wanting, partly because they fail to distinguish between two different kinds of praiseworthiness. Finally, the author sketches three implications of the thesis that doxastic responsibility entails the ability to believe otherwise: counterfactual construals of responsible belief might be tenable, the deontological conception of epistemic justification needs revision on an important point, and there might be an important asymmetry between beliefs on the one hand and actions and many non-doxastic consequences on the other. (shrink)

The success of the AGM paradigmn, Gis remarkable, as even a quick look at the literature it has generated will testify. But it is also remarkable, at least in hindsight, how limited was the original effort. For example, the theory concerns the beliefs of just one agent; all incoming information is accepted; belief change is uniquely determined by the new information; there is no provision for nested beliefs. And perhaps most surprising: there is no analysis of iterated change.

Belief revision theory studies how an ideal doxastic agent should revise her beliefs when she receives new information. In part I, I have first presented the AGM theory of belief revision. Then I have focused on the problem of iterated belief revisions. In part II, I will first present ranking theory (Spohn 1988). Then I will show how it solves the problem of iterated belief revisions. I will conclude by sketching two areas of future research.

How should an agent revise her epistemic state in the light of doxastic disagreement? The problems associated with answering this question arise under the assumption that an agent’s epistemic state is best represented by her degree of belief function alone. We argue that for modeling cases of doxastic disagreement an agent’s epistemic state is best represented by her confirmation commitments and the evidence available to her. Finally, we argue that given this position it is possible to provide an (...) adequate answer to the question of how to rationally revise one’s epistemic state in the light of disagreement. (shrink)

We propose a dynamic hyperintensional logic of belief revision for non-omniscient agents, reducing the logical omniscience phenomena affecting standard doxastic/epistemic logic as well as AGM belief revision theory. Our agents don’t know all a priori truths; their belief states are not closed under classical logical consequence; and their belief update policies are such that logically or necessarily equivalent contents can lead to different revisions. We model both plain and conditional belief, then focus on dynamic belief revision. (...) The key idea we exploit to achieve non-omniscience focuses on topic- or subject matter-sensitivity: a feature of belief states which is gaining growing attention in the recent literature. (shrink)

Belief revision theory studies how an ideal doxastic agent should revise her beliefs when she receives new information. In part I I will first present the AGM theory of belief revision (Alchourrón & Gärdenfors & Makinson 1985). Then I will focus on the problem of iterated belief revisions.

I present a possible worlds semantics for a hyperintensional belief revision operator, which reduces the logical idealization of cognitive agents affecting similar operators in doxastic and epistemic logics, as well as in standard AGM belief revision theory. (Revised) belief states are not closed under classical logical consequence; revising by inconsistent information does not perforce lead to trivialization; and revision can be subject to ‘framing effects’: logically or necessarily equivalent contents can lead to different revisions. Such results (...) are obtained without resorting to non-classical logics, or to non-normal or impossible worlds semantics. The framework combines, instead, a standard semantics for propositional S5 with a simple mereology of contents. (shrink)

Dynamic doxastic logic (DDL) is used in connexion with theories of belief revision. Here we try to show that languages of DDL are suitable also for discussing aspects of default logic. One ingredient of our analysis is a concept of coherence-as-ratifiability.

In this paper we distinguish between various kinds of doxastic theories. One distinction is between informal and formal doxastic theories. AGM-type theories of belief change are of the former kind, while Hintikka’s logic of knowledge and belief is of the latter. Then we distinguish between static theories that study the unchanging beliefs of a certain agent and dynamic theories that investigate not only the constraints that can reasonably be imposed on the doxastic states of a rational agent (...) but also rationality constraints on the changes of doxastic state that may occur in such agents. An additional distinction is that between non-introspective theories and introspective ones. Non-introspective theories investigate agents that have opinions about the external world but no higher-order opinions about their own doxasticnstates. Standard AGM-type theories as well as the currently existing versions of Segerberg’s dynamic doxastic logic (DDL) are non-introspective. Hintikka-style doxastic logic is of course introspective but it is a static theory. Thus, the challenge remains to devise doxastic theories that are both dynamic and introspective. We outline the semantics for truly introspective dynamic doxastic logic, i.e., a dynamic doxastic logic that allows us to describe agents who have both the ability to form higher-order beliefs and to reflect upon and change their minds about their own (higher-order) beliefs. This extension of DDL demands that we give up the Preservation condition on revision. We make some suggestions as to how such a non-preservative revision operation can be constructed. We also consider extending DDL with conditionals satisfying the Ramsey test and show that Gärdenfors’ well-known impossibility result applies to such a framework. Also in this case, Preservation has to be given up. (shrink)

W.V. Quine is committed to the claim that all beliefs are rationally revisable; Jerrold Katz has argued that this commitment is unstable on grounds of self-application. The subsequent discussion of this issue has largely proceeded in terms of the logic of belief revision, but there is also an issue here for the treatment of Quine’s views in a doxastic modal system. In this paper I explore the treatment of Quinean epistemology in modal terms. I argue that a set (...) of formal revisability desiderata can be distilled from Quine’s epistemic writings, and that there are demonstrably coherent and non-trivial systems that meet these conditions. (shrink)

The theory of belief revision deals with (rational) changes in beliefs in response to new information. In the literature a distinction has been drawn between belief revision and belief update (see [6]). The former deals with situations where the objective facts describing the world do not change (so that only the beliefs of the agent change over time), while the letter allows for situations where both the facts and the doxastic state of the agent change over time. (...) We focus on belief revision and propose a temporal framework that allows for iterated revision. We model the notion of “minimal” or “conservative” belief revision by considering logics of increasing strength. We move from one logic to the next by adding one or more axioms and show that the corresponding logic captures more stringent notions of minimal belief revision. The strongest logic that we propose provides a full axiomatization of the well-known AGM theory of belief revision. (shrink)

I want to look at recent developments of representing AGM-style belief revision in dynamic epistemic logics and the options for doing something similar for ranking theory. Formally, my aim will be modest: I will define a version of basic dynamic doxastic logic using ranking functions as the semantics. I will show why formalizing ranking theory this way is useful for the ranking theorist first by showing how it enables one to compare ranking theory more easily with other approaches (...) to belief revision. I will then use the logic to state an argument for defining ranking functions on larger sets of ordinals than is customary. Secondly, I will argue that the only way to extend the account of belief revision given by ranking theory to higher-order beliefs and revisions is by continuing the approach taken by me and defining ranking theoretical equivalents of dynamic epistemic logics. For proponents of dynamic epistemic logic, such logics will naturally be of interest provided they are convinced of the revision operator defined by ranking theory. (shrink)

Dynamic doxastic logic (DDL) is the modal logic of belief change. In basic DDL a modal operator [* ϕ ] carries the informal meaning "after the agent has revised his beliefs by ϕ " or "after the agent has accepted the information that ϕ "; it is assumed that the arguments of the star operator * are pure Boolean formulae. That assumption is discarded in full DDL where any pure doxastic formula may be an argument. As noted by (...) other authors, a straight-forward extension of the theory from basic DDL to full DDL invites problems of the kind first discussed by G. E. Moore. In this paper it is argued that a way to escape those problems is to redefine revision in a way that seems appropriate for this semantically richer context. The paper deals only with the one-agent case, but the approach can be extended to the case of multiple agents. (shrink)

In the context of a general framework for belief dynamics which interprets revision as doxastic constraint satisfaction, we discuss a proposal for revising quasi-probabilistic belief measures with finite sets of graded conditionals. The belief states are ranking measures with divisible values (generalizing Spohn’s epistemology), and the conditionals are interpreted as ranking constraints. The approach is inspired by the minimal information paradigm and based on the principle-guided canonical construction of a ranking model of the input conditionals. This is achieved (...) by extending techniques known from conditional default reasoning. We give an overview of how it handles different principles for conditional and parallel revision and compare it with similar accounts. (shrink)

Belief revision theories standardly endorse a principle of intensionality to the effect that ideal doxastic agents do not discriminate between pieces of information that are equivalent within classical logic. I argue that this principle should be rejected. Its failure, on my view, does not require failures of logical omniscience on the part of the agent, but results from a view of the update as _mighty_: as encoding what the agent learns might be the case, as well as what (...) must be. The view is motivated by consideration of a puzzle case, obtained by transposing into the context of belief revision a kind of scenario that Kit Fine has used to argue against intensionalism about counterfactuals. Employing the framework of truthmaker semantics, I go on to develop a novel account of belief revision, based on a conception of the update as mighty, which validates natural hyperintensional counterparts of the usual AGM postulates. (shrink)

The traditional connection between logic and reasoning has been under pressure ever since Gilbert Harman attacked the received view that logic yields norms for what we should believe. In this article I first place Harman's challenge in the broader context of the dialectic between logical revisionists like Bob Meyer and sceptics about the role of logic in reasoning like Harman. I then develop a formal model based on contemporary epistemic and doxastic logic in which the relation between logic and (...) norms for belief can be captured. (shrink)

In [11] it is shown how propositional dynamic logic (PDL) can be interpreted as a logic of belief revision that extends the logic of communication and change (LCC) given in [7]. This new version of epistemic/doxastic PDL does not impose any constraints on the basic relations and because of this it does not suffer from the drawback of LCC that these constraints may get lost under updates that are admitted by the system. Here, we will impose one constraint, (...) namely that the agent’s plausibility relations are linked. Linkedness is a natural extension of local connectedness to the multi-agent case and it assures that we know the agent’s preferences between all relevant alternatives. Since the belief updates that are used in [11] may not preserve linkedness, we limit ourselves to a particular kind of belief change that does preserve it. Our framework has obvious connections to coalition logic [17] and social choice theory [19]. We show how we can use it to model consensus seeking in plenary Dutch meetings. In Dutch meetings, a belief update is done for all agents in the meeting if a majority beliefs the proposition that is under discussion. A special case of these meetings is judgement aggregation, and we apply our framework to the discursive dilemma in this field [15]. (shrink)

In ‘belief revision’ a theory is revised with a formula φ resulting in a revised theory . Typically, is in , one has to give up belief in by a process of retraction, and φ is in . We propose to model belief revision in a dynamic epistemic logic. In this setting, we typically have an information state (pointed Kripke model) for the theory wherein the agent believes the negation of the revision formula, i.e., wherein is true. (...) The revision with φ is a program *φ that transforms this information state into a new information state. The transformation is described by a dynamic modal operator [*φ], that is interpreted as a binary relation [ [*φ] ] between information states. The next information state is computed from the current information state and the belief revision formula. If the revision is successful, the agent believes φ in the resulting state, i.e., Bφ is then true. To make this work, as information states we propose ‘doxastic epistemic models’ that represent both knowledge and degrees of belief. These are multi-modal and multi-agent Kripke models. They are constructed from preference relations for agents, and they satisfy various characterizable multi-agent frame properties. Iterated, revocable, and higher-order belief revision are all quite natural in this setting. We present, for an example, five different ways of such dynamic belief revision. One can also see that as a non-deterministic epistemic action with two alternatives, where one is preferred over the other, and there is a natural generalization to general epistemic actions with preferences. (shrink)

In this paper we forge a connection between dynamic epistemic logics of belief revision on one hand and studies of collective judgement and multi-agent preference change on the other. Belief revision in the spirit of dynamic epistemic logic uses updating with relational substitutions to change the beliefs of individual agents. Collective judgement in social choice theory studies the collective outcomes of individual belief changes. We start out from the logic of communication and change (LCC), which is basically epistemic (...) propositional dynamic logic (PDL) extended with update action modalities. We show how epistemic PDL can be made to handle belief operators. Our new version of epistemic/doxastic PDL does not impose any constraints on the basic relations. Because of this it does not suffer from the drawback of LCC that constraints on epistemic relations, such as transitivity and reflexivity, may get lost under updates that are admitted by the system. After introducing the base system without constraints, we study the effects of imposing a single constraint, namely the constraint that the agent’s preference relations are linked. Linkedness is a natural extension of local connectedness to the multi-agent case. It assures that if Alice prefers y to x and Bob prefers z to x, then both Alice and Bob can make up their minds when given a choice between y and z. Since general belief changes may not preserve linkedness, we propose a recipe for belief change that does preserve it. Finally, we show that the resulting framework can be used to model consensus seeking procedures. We focus on the case of plenary Dutch meetings. In Dutch meetings, a belief change (or rather: preference change) is performed for all agents in the meeting if a majority believes (or: is in favour of) the proposition that is under discussion. A special case of these meetings is judgement aggregation, and we apply our framework to the discursive dilemma in.. (shrink)

In ‘belief revision’ a theory\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\cal K}$$\end{document} is revised with a formula φ resulting in a revised theory \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\cal K}\ast\varphi$$\end{document}. Typically, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\neg\varphi$$\end{document} is in \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\cal K}$$\end{document}, one has to give up belief in \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\neg\varphi$$\end{document} by a (...) process of retraction, and φ is in \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\cal K}\ast\varphi$$\end{document}. We propose to model belief revision in a dynamic epistemic logic. In this setting, we typically have an information state (pointed Kripke model) for the theory \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\cal K}$$\end{document} wherein the agent believes the negation of the revision formula, i.e., wherein \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$B\neg\varphi$$\end{document} is true. The revision with φ is a program *φ that transforms this information state into a new information state. The transformation is described by a dynamic modal operator [*φ], that is interpreted as a binary relation [ [*φ] ] between information states. The next information state is computed from the current information state and the belief revision formula. If the revision is successful, the agent believes φ in the resulting state, i.e., Bφ is then true. To make this work, as information states we propose ‘doxastic epistemic models’ that represent both knowledge and degrees of belief. These are multi-modal and multi-agent Kripke models. They are constructed from preference relations for agents, and they satisfy various characterizable multi-agent frame properties. Iterated, revocable, and higher-order belief revision are all quite natural in this setting. We present, for an example, five different ways of such dynamic belief revision. One can also see that as a non-deterministic epistemic action with two alternatives, where one is preferred over the other, and there is a natural generalization to general epistemic actions with preferences. (shrink)

This paper shows how propositional dynamic logic can be interpreted as a logic for multi-agent belief revision. For that we revise and extend the logic of communication and change of [9]. Like LCC, our logic uses PDL as a base epistemic language. Unlike LCC, we start out from agent plausibilities, add their converses, and build knowledge and belief operators from these with the PDL constructs. We extend the update mechanism of LCC to an update mechanism that handles belief change (...) as relation substitution, and we show that the update part of this logic is more expressive than either that of LCC or that of doxastic/epistemic PDL with a belief change modality. It is shown that the properties of knowledge and belief are preserved under any update, and that the logic is complete. © 2008 Springer-Verlag Berlin Heidelberg. (shrink)

This paper addresses the question whether the past couple of decades of formal research in belief revision offers evidence of a new psychologism in logic. In the first part I examine five potential arguments in favour of this thesis and find them all wanting. In the second part of the paper I argue that belief revision research has climbed up a hierarchy of models for the change of doxastic states that appear to be clearly normative at the (...) bottom, but are more amenable to an empirical-descriptive interpretation on higher levels. I conclude that this observation might offer a foothold for the thesis that there is a new psychologism in logic. (shrink)

Argumentation is a dialogical attempt to bring about a desired change in the beliefs of another agent – that is, to trigger a specific belief revision process in the mind of such agent. However, so far formal models of belief revision widely neglected any systematic comparison with argumentation theories, to the point that even the simplest argumentation structures cannot be captured within such models. In this essay, we endeavour to bring together argumentation and belief revision in the (...) same formal framework, and to highlight the important role played by Toulmin’s layout of argument in fostering such integration. (shrink)

I propose a novel hyperintensional semantics for belief revision and a corresponding system of dynamic doxastic logic. The main goal of the framework is to reduce some of the idealisations that are common in the belief revision literature and in dynamic epistemic logic. The models of the new framework are primarily based on potentially incomplete or inconsistent collections of information, represented by situations in a situation space. I propose that by shifting the representational focus of doxastic (...) models from belief sets to collections of information, and by defining changes of beliefs as artifacts of changes of information, we can achieve a more realistic account of belief representation and belief change. The proposed dynamic operation suggests a non-classical way of changing beliefs: belief revision occurs in non-explosive environments which allow for a non-monotonic and hyperintensional belief dynamics. A logic that is sound with respect to the semantics is also provided. (shrink)

This talk shows how propositional dynamic logic (PDL) can be interpreted as a logic for multi-agent knowledge update and belief revision, or as a logic of preference change, if the basic relations are read as preferences instead of plausibilities. Our point of departure is the logic of communication and change (LCC) of [9]. Like LCC, our logic uses PDL as a base epistemic language. Unlike LCC, we start out from agent plausibilities, add their converses, and build knowledge and belief (...) operators from these with the PDL constructs. We extend the update mechanism of LCC to an update mechanism that handles belief change as relation substitution, and we show that the update part of this logic is more expressive than either that of LCC or that of epistemic/doxastic PDL with a belief change modality. Next, we show that the properties of knowledge and belief are preserved under any update, unlike in LCC. We prove completeness of the logic and give examples of its use. If there is time, we will also look at the preference interpretation of the system, and at preference change scenarios that can be modelled with it. (shrink)

The degree of doxastic revision required in response to evidence of disagreement is typically thought to be a function of our beliefs about (1) our interlocutor’s familiarity with the relevant evidence and arguments, and their intellectual capacities and virtues, relative to our own, or (2) the expected probability of our interlocutor being correct, conditional on our disagreeing. While these two factors are typically used interchangeably, I show that they have an inverse correlation in cases of disagreement about politically (...) divisive propositions. This presents us with a puzzle about the epistemic impact of disagreement in these cases. The most significant disagreements on (1) are the least significant disagreements on (2), and vice versa. I show that assessing the epistemic status of an interlocutor by reference to either (1) or (2) has uncomfortable consequences in these cases. I then argue that this puzzle cannot be escaped by claiming that we usually have dispute-independent reason to reject the significance of politically charged disagreement altogether. (shrink)

While it seems hard to deny the epistemic significance of a disagreement with our acknowledged epistemic peers, there are certain disagreements, such as philosophical disagreements, which appear to be permissibly sustainable. These two claims, each independently plausible, are jointly puzzling. This paper argues for a solution to this puzzle. The main tenets of the solution are two. First, the peers ought to engage in a deliberative activity of discovering more about their epistemic position vis-à-vis the issue at stake. Secondly, the (...) peers are permitted to do so while entertaining a sui generis doxastic attitude of hypothesis. (shrink)

Gilbert Harman’s famous principle of Clutter Avoidance commands that “one should not clutter one’s mind with trivialities". Many epistemologists have been inclined to accept Harman’s principle, or something like it. This is significant because the principle appears to have robust implications for our overall picture of epistemic normativity. Jane Friedman (2018) has recently argued that one potential implication is that there are no genuine purely evidential norms on belief revision. In this paper, we present some new objections to a (...) suitably formulated version of the clutter principle qua norm on belief revision. Moreover, we argue that the clutter principle is best understood as a norm on non-doxastic stages of inquiry. In our view, it is a norm of asking and considering questions rather than a norm of settling on an answer to a question by forming a belief. (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)

I argue that the skeptical force of a disagreement is mitigated to the extent that it is fundamental, where a fundamental disagreement is one that is driven by differences in epistemic starting points. My argument has three steps. First, I argue that proponents of conciliatory policies have good reason to affirm a view that I call “instrumentalism,” a view that commends treating our doxastic inclinations like instrumental readouts. Second, I show that instrumentalism supplies a basis for demanding conciliatory requirements (...) in superficial disagreements but not in fundamental disagreements. Third, I argue that the frequently invoked “independence” principle, which arguably would require significant conciliation in fundamental disputes, is unmotivated in light of the explanatory power of instrumentalism. The most plausible conciliatory view, then, is a weak conciliationism that features instrumentalism rather than independence as the central principle, and that therefore gives us a principled basis for thinking that fundamental disagreements should occasion less doxastic revision than shallow disagreements. (shrink)

Alex Worsnip has recently argued against conciliatory views that say that the degree of doxastic revision required in light of disagreement is a function of one’s antecedent reliability estimates for oneself and one’s disputant. According to Worsnip, the degree of doxastic revision is also sensitive to the resilience of these estimates; in particular, when one has positive “net resilience,” meaning that one is more confident in one’s estimate of one’s own reliability than in one’s estimate of (...) the disputant’s reliability, less doxastic revision is required. I show that Worsnip’s Resilience Account, however intuitive it may be, sometimes issues prescriptions that are clearly irrational. I then argue that Worsnip’s criticisms of “extreme conciliationism” are mistaken. The discussion brings out several important lessons for the epistemology of disagreement: first, while positive net resilience does not affect the degree of conciliation required in one-shot disagreements, over multiple disagreements it may diminish or magnify the required degree of conciliation; second, a common way of framing the disagreement debate is misguided; and third, the focus of the disagreement debate should not be on whether reliability estimates should determine the degree of conciliation, but on what reasons may legitimately ground reliability estimates. (shrink)

When one thinks—knows, believes, imagines—that something is the case, one’s thought has a topic: it is about something, towards which one’s mind is directed. What is the logic of thought, so understood? This book begins to explore the idea that, to answer the question, we should take topics seriously. It proposes a hyperintensional account of the propositional contents of thought, arguing that these are individuated not only by the set of possible worlds at which they are true, but also by (...) their topic: what they are about. The book then builds epistemic, doxastic, probabilistic, and conditional logics based on this view. It applies them to issues ranging from dogmatism, scepticism, and epistemic fallibilism, to imagination and suppositional reasoning, belief revision, framing effects, and the acceptability of indicative conditionals. (shrink)

It has been widely discussed, in recent years, which is the rational doxastic reaction in the face of peer disagreement. But not much has been said about aninteresting instance of that debate: philosophical peer disagreement. That is precisely what I will be concerned with in this paper. First, I will offer a definition ofphilosophical peer that introduces the idea of an epistemic perspective. The proposed definition allows for a doublé distinction: between Strong and Weak Peers, and between Strong and (...) Weak Disagreements. Based on these distinctions, I will defend that different doxastic reactions are required depending on the type of disagreement at issue. On the one hand, in the face of Weak Disagreement, we should be conciliatory. Cases of Strong disagreement, in turn, shouldn’t motívate a doxastic revision. In order to argue for that, some refinements into the notion of Rational Uniqueness will be needed. (shrink)

The main purpose of this paper is to propose and defend anew definition of synonymy. Roughly (and slightly misleadingly), theidea is that two expressions are synonymous iff intersubstitutions insentences preserve the degree of doxastic revisability. In Section 1 Iargue that Quine''s attacks on analyticity leave room for such adefinition. The definition is presented in Section 2, and Section 3elaborates on the concept of revisability. The definition is defendedin Sections 4 and 5. It is, inter alia, shown that the definition (...) hasdesired formal properties. In Sections 6 and 7 I briefly comment on,first, the relation of the definition to Quine''s later ideas about (stimulus)synonymy, and, second, its relation to a general, interlinguistic, conceptof meaning. (shrink)

The ways in which we exercise intentional agency are varied. I take the domain of intentional agency to include all that we intentionally do versus what merely happens to us. So the scope of our intentional agency is not limited to intentional action. One can also exercise some intentional agency in omitting to act and, importantly, in producing the intentional outcome of an intentional action. So, for instance, when an agent is dieting, there is an exercise of agency both with (...) respect to the agent’s actions and omissions that constitute her dieting behavior and in achieving the intended outcome of losing weight. In our mental lives we exercise intentional agency both in performing mental actions and when we intentionally produce certain outcomes at which our mental actions are aimed. The nature and scope of our intentional agency in our mental lives with respect to controlling the acquisition of mental states such as belief, desire, and intention is a topic that is of interest in its own right. In this essay, I will focus solely on our control over coming to believe. Understanding what sort of control we have our beliefs has far-reaching implications. For instance, theorizing about self-deception and wishful thinking is aided by theorizing about what if any intentional agency we can exercise with respect to acquiring beliefs. Another often mentioned concern that motivates thinking about doxastic agency comes from religion (when conversion requires a change of belief). We also hold persons morally and epistemically responsible for beliefs they have or fail to have. Finally, some deontological theories of epistemic justification require that agents be able to exercise a robust form of doxastic control. Fruitful work on any of these problems requires that we have an account of our intentional agency in acquiring beliefs. There are at least three loci of doxastic control. The first is over acquiring beliefs. The second is over maintaining beliefs. The third is over how we use our beliefs. I am chiefly concerned with the first locus of doxastic control in this essay, but I will say something about the second locus along the way. Also, I will only consider one way we might exercise control over acquiring beliefs. Specifically, I will present an argument against direct doxastic voluntarism (DDV). By “DDV” I mean to refer to the thesis that it is conceptually possible for agents to consciously exercise the same sort of direct voluntary control over coming to acquire a doxastic attitude—such as belief, suspension of belief, and disbelief—that they exercise over uncontroversial basic actions. If DDV is correct, then coming to believe can be a basic action-type. DDV, or something very close to it, was Bernard Williams’ target in his 1973 paper, “Deciding to Believe.” Williams’s argument is widely regarded as having been a failure. But I think that Williams was on to something in his paper. Hence, in this paper, while I do not attempt to resurrect Williams’s argument, I develop and defend a revised argument for a thesis that is quite close to Williams’s. I will proceed as follows. First, I will discuss Bernard Williams’ (1973) failed attempt at showing that DDV is conceptually impossible. This will be followed by a discussion of some constraints on our belief-forming activities. I will then clarify my target a bit more than Williams does in his original paper. Finally, I will present my own argument against the conceptual possibility of DDV. (shrink)