In this paper, I argue that some plausible principles concerning which credences are rationally permissible for agents given information about one another’s epistemic and credal states have some surprising consequences for which credences an agent ought to have in light of self-locating information. I provide a framework that allows us to state these constraints and draw out these consequences precisely. I then consider and assess the prospects for rejecting these prima facie plausible principles.

What is common knowledge? According to the dominant iterative model, a group of people commonly knows that p if and only if they each individually know that p, and they furthermore each know that they each know that p, and so on to infinity. According to the integrative model proposed in this paper, a group commonly knows that p when its members are united in a state of mind of the type whose contents must be true. Epistemic integration within a (...) group is enabled by symmetrical signalling processes such as eye contact. In conversational dyads, symmetrical processing operates on pairs of signals produced by the two sides in a familiar format: speakers generate content for joint attention in main channel communication, and addressees evaluate that content in backchannel communication. Processes of reinforcement learning shape our pairwise signalling, driving the accumulation of common knowledge, both in response to extrinsic reward for coordinated action, and in response to the intrinsic reward of curiosity. Where the iterative model caps the epistemic performance of the group at the level of its weakest member, the integrative model of common knowledge shows how groups working together can outperform their strongest member working alone. (shrink)

What is it to know someone? Epistemologists rarely take up this question, though recent developments make such inquiry possible and desirable. This paper advances an account of how such interpersonal knowledge goes beyond mere propositional and qualitative knowledge about someone, giving a central place to second-personal treatment. It examines what such knowledge requires, and what makes it distinctive within epistemology as well as socially. It assesses its theoretic value for several issues in moral psychology, epistemic injustice, and philosophy of mind. (...) And it offers an account of the complex content in play if interpersonal knowledge is to be understood in terms of its mental states and their functions. (shrink)

Common knowledge is ubiquitous in our lives and yet there remains considerable uncertainty about how to model or understand it. Standard analyses of common knowledge end up being challenged by either regress or circularity which then give rise to well-known paradoxes of practical reasoning, such as the Two Generals’ Paradox. This paper argues that the nature and utility of common knowledge can be illuminated by appeal to Wittgenstein’s Hinge Epistemology. It is argued that those things that we standardly think of (...) as being common knowledge in our lives are the same as those that Wittgenstein identified as hinge certainties. This identification of common knowledge with hinge certainties allows us to resolve the regress problem for common knowledge and explain how the Two Generals’ Paradox arises. (shrink)

Some arguments against the assumption that ordinary people may share common knowledge are sound. The apparent cost of such arguments is the rejection of scientific theories that appeal to common knowledge. My proposal is to accept the arguments without rejecting the theories. On my proposal, common knowledge is shared by ideally rational people, who are not just mathematically simple versions of ordinary people. They are qualitatively different from us, and theorizing about them does not lead to predictions about our behavior. (...) Nevertheless, models of action that assume common knowledge have a role to play in our understanding of collective rationality. (shrink)

We introduce the rejection game, designed to formalize the interaction between interlocutors in a Stalnakerian conversation: a speaker who asserts something and a listener who may accept or reject. The rejection game is similar to other signalling games known to the literature in economics and biology. We point out similarities and differences, and propose an application in linguistics. We uncover basic conditions under which the Gricean maxim of quality emerges from incentives among the players, providing evidence for a functionalist understanding (...) of the Gricean program. (shrink)

We focus on a sui generis grounding move in Hindi-Urdu dialogue, namely 'voh hi na'. 'Voh' is third person pronoun and can function as a propositional anaphor in dialogue. 'Hi' and 'na' are two discourse particles in Hindi-Urdu. A dataset consisting of minimal pairs of dialogues is presented to get a better sense of the move. Using dynamic models of discourse structure, we propose a semantics for 'voh hi na' in terms of its update effects.

Recent scoreboard models of conversation, in addition to modeling update effects of assertions and questions, also make sense of how one may react to such discourse moves. An account of acceptance and rejection is captured by Farkas & Bruce (2010), while Bledin & Rawlins (2020) have recently made sense of how one may resist an assertion too. For rejection and resistance of assertions, truth comes out to be a crucial notion. Between X and Y, if Y doesn't believe p to (...) be true, then Y might resist or reject X's assertion of p. For questions however, truth cannot serve this purpose. A complete model of discourse would seek to offer explanation of resisting questions. Much like Bledin & Rawlins, one can non-exhaustively enumerate a class of resistance moves. In many ways, one can resist a request to make a particular question QUD. In this paper, we raise following question: which notion can serve to explain question uptake in discourse? In our paper, we show how the expected utility value (EUV) of questions can serve this role for questions. EUV is used by van Rooij (2003) to give an account of interpretation of questions; we think it can serve our intended purposes too. To demonstrate plausibility, we build a workable formalism. (shrink)

Williamson (2000) argues that the KK principle is inconsistent with knowledge of margin for error in cases of inexact perceptual observations. This paper argues, primarily by analogy to a different scenario, that Williamson's argument is fallacious. Margin for error principles describe the agent's knowledge as a result of an inexact perceptual event, not the agent's knowledge state in general. Therefore, epistemic agents can use their knowledge of margin for error at most once after a perceptual event, but not more. This (...) insight blocks a crucial step in Williamson's original argument. Along the way, the value of standard epistemic logic for analyzing margin for error reasoning is challenged. (shrink)

kk states that knowing entails knowing that one knows, and K¬K states that not knowing entails knowing that one does not know. In light of the arguments against kk and K¬K⁠, one might consider modally qualified variants of those principles. According to weak kk, knowing entails the possibility of knowing that one knows. And according to weakK¬K⁠, not knowing entails the possibility of knowing that one does not know. This paper shows that weak kk and weakK¬K are much stronger than (...) they initially appear. Jointly, they entail kk and K¬K⁠. And they are susceptible to variants of the standard arguments against kk and K¬K⁠. This has interesting implications for the debate on positive introspection and for deeper issues concerning the structure and limits of knowability. (shrink)

Assertions are often accepted without being understood, a phenomenon I call stupefying. I argue that stupefying can be a means for conversational manipulation that works through at-issue content, in contrast with the not-at-issue and back-door speech act routes identified by others. This shows that we should reject a widely assumed connection between attention and at-issue content. In exploring why stupefying happens, it also emerges that stupefying has important cooperative uses, in addition to its manipulative ones, and so should not be (...) avoided altogether. (shrink)

What are the objects of speaker meaning? The traditional answer is: propositions. The traditional answer faces an important challenge: if propositions are the objects of speaker meaning then there must be specific propositions that speakers intend their audiences to recover. Yet, speakers typically exhibit a degree of indifference regarding how they are interpreted, and cannot rationally intend for their audiences to recover specific propositions. Therefore, propositions are not the objects of speaker meaning (Buchanan 2010; MacFarlane 2020a; 2020b; and Abreu Zavaleta (...) 2021). In this paper I do two things. Firstly, I outline a collective analogue of this challenge that undermines the most prominent responses to the original challenge. Secondly, I provide a new solution: typical utterances are backed by a cluster of partial communicative intentions. This response resolves both individual and collective variants of the problem and allows us to retain the traditional propositional view of speaker meaning. (shrink)

Communication can be risky. Like other kinds of actions, it comes with potential costs. For instance, an utterance can be embarrassing, offensive, or downright illegal. In the face of such risks, speakers tend to act strategically and seek ‘plausible deniability’. In this paper, we propose an account of the notion of deniability at issue. On our account, deniability is an epistemic phenomenon. A speaker has deniability if she can make it epistemically irrational for her audience to reason in certain ways. (...) To avoid predictable confusion, we distinguish deniability from a practical correlate we call ‘untouchability’. Roughly, a speaker has untouchability if she can make it practically irrational for her audience to act in certain ways. These accounts shed light on the nature of strategic speech and suggest countermeasures against strategic speech. (shrink)

We argue that there is a variety of convention, effective coordinating agreement, that has not been adequately identified in the literature. Its distinctive feature is that it is a structure of conditional we-intentions of parties, unlike more familiar varieties of convention, which are structures of expectations and preferences or obligations. We argue that status functions constitutively involve this variety of convention, and that what is special about it explains, and gives precise content to the central feature of status functions, namely, (...) that objects with status functions can perform their functions only insofar as they have been collectively accepted as having them. (shrink)

Joint attention is an everyday phenomenon in which two or more individuals attend to an object, event process or property in the presence of each other, such that their attention to that object is to some degree intertwined with the other’s attention to it. This paper argues that joint attention has the normative role of enabling subjects to coordinate their actions in a way that would contribute to the rational execution of a joint action in accordance with a prior shared (...) plan or shared intention. This understanding of the normative function of joint attention underpins a particular understanding of the nature of joint attention: what I shall call Rich Relationalism. Rich Relationalism argues for the view that joint attention acts as an epistemically significant interface between the world, other people, and their background plans and concepts. It understands joint attention as an object-dependent, conceptually structured, token experiential state that is shared by two (or more) people. It can be contrasted with non-relational (i.e., Representational or Enactivist) accounts of joint attention on the one hand, and Lean Relationalist accounts on the other (such as John Campbell’s influential account). (shrink)

Contextology is the science of the dynamics of the conversational context. Contextology formulates laws governing how the shared information states of interlocutors evolve in response to assertion. More precisely, the contextologist attempts to construct a function which, when provided with just a conversation’s pre-update context and the content of an assertion, delivers that conversation’s post-update context. Most contextologists have assumed that the function governing the evolution of the context is simple: the post-update context is just the pre-update context intersected with (...) the content of the assertion. We argue that this assumption is wrong: not only is it false, it is also incoherent given standard contextological assumptions. Moreover, it is impossible in principle to revise it to correctly describe the dynamics of context. We conclude that there can be no science of Contextology. The laws governing the evolution of the context in response to assertion must make essential reference to the private information states of interlocutors. (shrink)

Joint attention occurs when two (or more) individuals attend together to some object. It has been identified by psychologists as an early form of our joint engagement, and is thought to provide us with an understanding of other minds that is basic in that sophisticated conceptual resources are not involved. Accordingly, it has also attracted the interest of philosophers. Moreover, a very recent trend in the psychological and philosophical literature on joint attention consists of developing the suggestion that it holds (...) partially in virtue of communication: it is because we share our thoughts or feelings about an object that our individual attention becomes joint. This paper unpacks the communicative suggestion in a way that accounts for joint attention's basicness. (shrink)

I put forward an externalist theory of social understanding. On this view, psychological sense making takes place in environments that contain both agent and interpreter. The spatial structure of such environments is social, in the sense that its occupants locate its objects by an exercise in triangulation relative to each of their standpoints. This triangulation is achieved in intersubjective interaction and gives rise to a triadic model of the social mind. This model can then be used to make sense of (...) others’ observed actions. Its possession plays a vital role in the development of the capacity for false belief reasoning. The view offers an integrated account of the development of social cognition from primary intersubjectivity to level-2 perspective taking. It incorporates insights from interactionism and mindreading theories of social cognition and thus offers a way out of the stalemate between defenders of the two views. Because psychological sense making is perspectival, the frame problem does not arise for social reasoners: the perspective they bring to bear on the action that is to be interpreted constrains the information they can select to make sense of what others do. (shrink)

Information can be public among a group. Whether or not information is public matters, for example, for accounts of interdependent rational choice, of communication, and of joint intention. A standard analysis of public information identifies it with (some variant of) common belief. The latter notion is stipulatively defined as an infinite conjunction: for p to be commonly believed is for it to believed by all members of a group, for all members to believe that all members believe it, and so (...) forth. This analysis is often presupposed without much argument in philosophy. Theoretical entrenchment or intuitions about cases might give some traction on the question, but give little insight about why the identification holds, if it does. The strategy of this paper is to characterize a practical-normative role for information being public, and show that the only things that play that role are (variants of) common belief as stipulatively characterized. In more detail: a functional role for “taking a proposition for granted” in non-isolated decision making is characterized. I then present some minimal conditions under which such an attitude is correctly held. The key assumption links this attitude to beliefs about what is public. From minimal a priori principles, we can argue that a proposition being public among a group entails common commitment to believe among that group. Later sections explore partial converses to this result, the factivity of publicity and publicity from the perspective of outsiders to the group, and objections to the aprioricity of the result deriving from a posteriori existential presuppositions. (shrink)

I argue that the social dimension of alienation, as discussed by Williams and Railton, has been underappreciated. The lesson typically drawn from their exchange is that moral theory poses a threat to the internal integrity of the agent, but there is a parallel risk that moral theory will implicitly construe agents as constitutively alienated from one another. I argue that a satisfying account of agency will need to make room for what I call ‘genuine ethical contact’ with others, both as (...) concrete objects in the world external to ourselves and as subjects who can recognize us reciprocally. (shrink)

Salience reasoning, many have argued, can help solve coordination problems, but only if such reasoning is supplemented by higher-order predictions, e.g. beliefs about what others believe yet others will choose. In this paper, I will argue that this line of reasoning is self-undermining. Higher-order behavioral predictions defeat salience-based behavioral predictions. To anchor my argument in the philosophical literature, I will develop it in response and opposition to the popular Lewisian model of salience reasoning in coordination games. This model imports the (...) problematic higher-order beliefs by way of a ‘symmetric reasoning’ constraint. In the second part of this paper, I will argue that a player may employ salience reasoning only if she suspends judgment about what others believe yet others will do. (shrink)

Cases of inexact observations have been used extensively in the recent literature on higher-order evidence and higher-order knowledge. I argue that the received understanding of inexact observations is mistaken. Although it is convenient to assume that such cases can be modeled statically, they should be analyzed as dynamic cases that involve change of knowledge. Consequently, the underlying logic should be dynamic epistemic logic, not its static counterpart. When reasoning about inexact knowledge, it is easy to confuse the initial situation, the (...) observation process, and the result of the observation; I analyze the three separately. This dynamic approach has far reaching implications: Williamson’s influential argument against the KK principle loses its force, and new insights can be gained regarding synchronic and diachronic introspection principles. (shrink)

The two of us commonly know a proposition just in case (i) we both know it, (ii) we both know that we both know it, (iii) we both know that we both know that we both know it, and so on. In a recent paper titled ‘Uncommon Knowledge’, Harvey Lederman (2018) argues against the possibility of common knowledge. His argument rests on the empirical claim that there are minor individual variations in how we perceive things. This motivates a principle about (...) perception: when two people are perceiving something and it perceptually appears a certain way to one of them, then for all that person knows, it perceptually appears a slightly different way to the other. In this paper, I challenge Lederman’s perceptual principle and thereby his argument. In particular, I argue that there are some circumstances in which things perceptually appear a certain way to me and nonetheless I know that they don’t perceptually appear in a slightly different way to you. Indeed, I argue that not only are there exceptions to the perceptual principle, but they are widespread. (shrink)

Why do we use epistemic modals like 'might'? According to Factualism, the function of 'might' is to exchange information about state-of-affairs in the modal universe. As an alternative to Factualism, this paper offers a game-theoretic rationale for epistemic possibility operators in a Bayesian setting. The background picture is one whereby communication facilitates coordination, but coordination could fail if there's too much uncertainty, since the players' ability to share a belief is undermined. However, 'might' and related expressions can be used to (...) reveal one's uncertainty, and exploit this to coordinate despite the lack of a common epistemic ground. The final result is a way to articulate a non-Factualist view of epistemic possibility modals that builds on their standard semantics. (shrink)

Presenting the first comprehensive, in-depth study of hyperintensionality, this book equips readers with the basic tools needed to appreciate some of current and future debates in the philosophy of language, semantics, and metaphysics. After introducing and explaining the major approaches to hyperintensionality found in the literature, the book tackles its systematic connections to normativity and offers some contributions to the current debates. The book offers undergraduate and graduate students an essential introduction to the topic, while also helping professionals in related (...) fields get up to speed on open research-level problems. (shrink)

According to standard assumptions in semantics, ordinary users of a language have implicit beliefs about the truth-conditions of sentences in that language, and they often agree on those beliefs. For example, it is assumed that if Anna and John are both competent users of English and the former utters ‘grass is green’ in conversation with the latter, they will both believe that that sentence is true if and only if grass is green. These assumptions play an important role in an (...) intuitively compelling picture of communication, according to which successful communication through literal assertoric utterances is normally effected thanks to our shared beliefs about the truth-conditions of the sentences uttered in the course of the conversation. Against these standard assumptions, this paper argues that the participants in a conversation rarely have the same beliefs about the truth-conditions of the sentences involved in a linguistic interaction. More precisely, it argues for Variance, the thesis that nearly every utterance is such that there is no proposition which more than one language user believes to be that utterance’s truth-conditional content. If Variance is true, we must reject the standard picture of communication. Towards the end of the paper I identify three ways in which ordinary conversations can be communication-like despite the truth of Variance and argue that the most natural amendments to the standard picture fail to explain them. (shrink)

In this paper, I argue that joint action permits a certain degree of luck. The cases I have in mind exhibit the following structure: each participant believes that the intended ends of each robustly support the joint action. This belief turns out to be false. Due to lucky circumstances, the discordance in intention never becomes common knowledge. However, common knowledge of the relevant intentions would have undermined the joint action altogether. The analysis of such cases shows the extent to which (...) common knowledge of the participants’ intentions can be harmful to joint action. This extends a recent line of research that has questioned the necessity of common knowledge in joint action. (shrink)

Philosophy and Phenomenological Research, EarlyView.

One does not simply predict where the other will go, which is wherever the first predicts the second to predict the first to go, and so ad infinitum. Not "What would I do if I were she?" but "What would I do if I were she wondering what she would do if she were wondering what I would do if I were she...?".

Shared intention normally leads to joint action. It does this, it is commonly said, only because it is a characteristically stable phenomenon, a phenomenon that tends to persist from the time it is formed until the time it is fulfilled. However, the issue of what the stability of shared intention comes down to remains largely undertheorized. My aim in this paper is to remedy this shortcoming. I argue that shared intention is a source of moral and epistemic reasons, that responsiveness (...) to such reasons on the part of each individual reinforces her own relevant attitudes, and that this enhances the stability of the shared intention as a whole. We thus discover an important self-reinforcing and stability-enhancing mechanism at the heart of shared intention and action. It follows from this proposal that the psychological commitment that an individual exhibits in joint action is normally a function not only of her own participatory intention, as often maintained, but also of her endorsement of the reasons created by her group’s shared intention to so act. (shrink)

We study shared intentions in what we call “loose groups”. These are groups that lack a codified organizational structure, and where the communication channels between group members are either unreliable or not completely open. We start by formulating two desiderata for shared intentions in such groups. We then argue that no existing account meets these two desiderata, because they assume either too strong or too weak an epistemic condition, that is, a condition on what the group members know and believe (...) about what the others intend, know, and believe. We propose an alternative, pooled knowledge, and argue that it allows formulating conditions on shared intentions that meet the two desiderata. (shrink)

This dissertation argues for Semantic Variance, the thesis that nearly every utterance is such that there is no proposition that more than one languge user takes to be that utterance's truth-conditional content. I argue that Semantic Variance is problematic for standard theories concerning the nature of communication, the epistemic significance of ordinary disputes, the semantics of speech reports, and the nature of linguistic competence. In response to the problems arising from the truth of Semantic Variance, I develop new accounts of (...) the transmission of relevant information, ordinary disputes, and the semantics of speech reports. Towards the end of the dissertation I outline a pluralistic account about the nature of communication and linguistic competence. (shrink)

For as long as there have been theories about common knowledge, they have been exposed to a certain amount of skepticism. Recent more sophisticated arguments question whether agents can acquire common attitudes and whether they are needed in social reasoning. I argue that this skepticism arises from assumptions about practical reasoning that, considered in themselves, are at worst implausible and at best controversial. A proper approach to the acquisition of attitudes and their deployment in decision making leaves room for common (...) attitudes. Postulating them is no worse off than similar idealizations that are usefully made in logic and economics. (shrink)

I put forward an externalist theory of social understanding. On this view, psychological sense making takes place in environments that contain both agent and interpreter. The spatial structure of such environments is social, in the sense that its occupants locate its objects by an exercise in triangulation relative to each of their standpoints. This triangulation is achieved in intersubjective interaction and gives rise to a triadic model of the social mind. This model can then be used to make sense of (...) others’ observed actions. Its possession plays a vital role in the development of the capacity for false belief reasoning. The view offers an integrated account of the development of social cognition from primary intersubjectivity to level-2 perspective taking. It incorporates insights from interactionism and mindreading theories of social cognition and thus offers a way out of the stalemate between defenders of the two views. Because psychological sense making is perspectival, the frame problem does not arise for social reasoners: the perspective they bring to bear on the action that is to be interpreted constrains the information they can select to make sense of what others do. (shrink)

This article proposes two interpretations of the concept of belief hierarchies in Bayesian game theory: the behaviorist interpretation and the mentalist interpretation. On the former, belief hierarchies are derived from the players’ preferences over acts. On the latter, they are causal mechanisms that are responsible for the players’ choices and preferences over acts. The claim is that the epistemic program in game theory is potentially confronted with a dilemma regarding which interpretation should be adopted. If the behaviorist interpretation of belief (...) hierarchies is retained, then Bayesian game theory cannot account for the players’ reasoning that leads to the generation of specific belief hierarchies and thus to the implementation of a specific strategy profile in a game. If the mentalist interpretation is retained, then belief hierarchies appear to be unnecessarily and unrealistically complex objects and that as a result they fail to provide reasonable epistemic foundations for various solution concepts. In other words, neither interpretation seems to allow the epistemic program to fulfill all its aims. I suggest however that the mentalist interpretation can be arranged to escape this dilemma. (shrink)

1. People standardly communicate by uttering phrases or sentences with certain intonation patterns, accompanied by facial expressions, eye contact and often a variety of gestures. If all goes well...