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)

Often, when we share information about ourselves, we contribute to people learning personal things about others. This may happen because what we share about ourselves can be used to infer personal information about others. Such dependencies have become known as privacy dependencies in the literature. It is sometimes claimed that the scope of the right to privacy should be expanded in light of such dependencies. For example, some have argued that inferring information about others can violate their right to privacy. (...) Others have argued that sharing personal information about yourself that license such inferences can by itself violate the right to privacy. In this paper, we argue that the latter view should be rejected. (shrink)

For the modal logic $\textsf {S4}^{C}_{I}$, we identify the class of completable $\textsf {S4}^{C}_{I}$-algebras and prove for them a Stone-type representation theorem. As a consequence, we obtain strong algebraic and topological completeness of the logic $\textsf {S4}^{C}_{I}$ in the case of local semantic consequence relations. In addition, we consider an extension of the logic $\textsf {S4}^{C}_{I}$ with certain infinitary derivations and establish the corresponding strong completeness results for the enriched system in the case of global semantic consequence relations.

This thesis develops a novel framework for explaining delusions. In Chapter 1, I introduce the two fundamental challenges posed by delusions: the evidence challenge lies in explaining the flagrant ways delusions flout evidence; and the specificity challenge lies in explaining the fact that patients’ delusions are often about a few specific themes, and patients rarely have a wide range of delusional or odd beliefs. In Chapter 2, I discuss the strengths and weaknesses of current theories of delusions, which typically appeal (...) to one or both of two factors: anomalous experience and reasoning abnormality. I argue that anomalous experience can help explain the specificity of delusions, but has difficulties in addressing the evidence challenge; reasoning abnormality can help address the evidence challenge, but has difficulties in explaining the specificity of delusions. This suggests that there may be an important factor that has not been captured by current theories of delusions. To search for this missing factor, in Chapter 3, I turn to normal believing. Inspired by the literature on Cartesian clarity and phenomenal dogmatism, I develop a dual-force framework of believing, according to which beliefs can be understood as the results of the interaction between the justificatory force and causal force of evidence and the justificatory force and causal force of clear experience, in which something clearly seems to be so to the subject. This framework suggests that the missing factor may be the clear experience with its distinctive phenomenal clarity that compels assent. In Chapter 4, I return to delusions, and argue that the dualforce framework can help us to get a better grip on some personal descriptions of delusions; make progress in addressing the evidence and specificity challenges of delusions; and shed new light on the underpinnings of delusions. In the end, I conclude with some remaining questions for future study. (shrink)

On a widely held characterization, triadic joint attention is the capacity to perceptually attend to an object or event together with another subject. In the last four decades, research in developmental psychology has provided increasing evidence of the crucial role that this capacity plays in socio-cognitive development, early language acquisition, and the development of perspective-taking. Yet, there is a striking discrepancy between the general agreement that joint attention is critical in various domains, and the lack of theoretical consensus on how (...) to account for it. This paper pursues three interrelated aims: (i) it examines the contrast between reductive and non-reductive views of (triadic) joint attention, by bringing into focus the notion of recursive mindreading; (ii) it assembles, advances, and discusses a number of arguments against reductive views; (iii) finally, in dialogue with some prominent non-reductive views, it outlines the case for a non-reductive view that gives pride of place to the idea that co-attenders relate to one another as a ‘you’. (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)

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 article investigates the relationship between for-me-ness and sociality. I start by pointing out some ambiguities in claims pursued by critics that have recently pressed on the relationship between the two notions. I next articulate a question concerning for-me-ness and sociality that builds on the idea that, occasionally at least, there is something it is like ‘for us’ to have an experience. This idea has been explored in recent literature on shared experiences and collective intentionality, and it gestures towards the (...) question of the extent to which some social interactions make a difference in the phenomenal character of their participants’ experiences. Finally, I present a construal of for-us-ness that complements the received understanding of for-me-ness, by drawing on Alfred Schutz’ concept of the we-relationship, and on the idea of second-personal awareness, i.e. awareness of a ‘you’. The current proposal provides a suitable account of some basic forms of phenomenally manifest social connectedness, in a way that is cognitively undemanding and without incurring the costs of a sui generis plural pre-reflective self-awareness. (shrink)

The meaning of an utterance is often enriched by the pragmatic context in which it is uttered. This is because in ordinary conversations we routinely and uncontroversially compress what we say, safe in the knowledge that those interpreting us will ‘add in’ the content we intend to communicate. Does the same thing hold true in the case of legal utterances like ‘This constitution protects the personal rights of the citizen’ or ‘the parliament shall have the power to lay and collect (...) taxes’? This article addresses this question from the perspective of the constitutional originalist—the person who holds that the meaning of a constitutional text is fixed at some historical moment. In doing so, it advances four theses. First, it argues that every originalist theory is committed to some degree of pragmatic enrichment, the debate is about how much. Second, that in determining which content gets ‘added in’, originalists typically hold to a common knowledge standard for enrichment, protestations... (shrink)

This paper offers a comparison of three different kinds of collective attitudes: aggregate, common, and corporate attitudes. They differ not only in their relationship to individual attitudes—e.g., whether they are “reducible” to individual attitudes—but also in the roles they play in relation to the collectives to which they are ascribed. The failure to distinguish them can lead to confusion, in informal talk as well as in the social sciences. So, the paper’s message is an appeal for disambiguation.

Traditional definitions of common ground in terms of iterative de re attitudes do not apply to conversations where at least one conversational participant is not acquainted with the other(s). I propose and compare two potential refinements of traditional definitions based on Abelard’s distinction between generality in sensu composito and in sensu diviso.

When you and I share an experience, each of us lives through a we-experience. The paper claims that we-experiences have unique phenomenality and structure. First, we-experiences’ phenomenality is characterised by the fact that they feel like ours to their subject. This specific phenomenality is contended to derive from the way these experiences self-represent: a we-experience exemplifies us-ness or togetherness because it self-represents as mine qua ours. Second, living through a we-experience together with somebody else is not to have this experience (...) in parallel with the experience of the other. Rather, the paper argues that a we-experience is partly co-constituted by the experience of the other. After offering an account of the phenomenality and constitution of we-experiences, which traces these two elements back to the subject’s self-understanding as a group member, the paper argues for the claim that an experience’s for-us-ness is committal to this experience being co-constituted by another we-experience. (shrink)

This article will compare and contrast two very different accounts of convention: the game-theoretical account of Lewis in Convention, and the account initially proposed by Margaret Gilbert (the present author) in chapter six of On Social Facts, and further elaborated here. Gilbert’s account is not a variant of Lewis’s. It was arrived at in part as the result of a detailed critique of Lewis’s account in relation to a central everyday concept of a social convention. An account of convention need (...) not be judged by that standard. Perhaps it reveals the nature of an important phenomenon. Looked at in that light, these very different accounts are not incompatible. Indeed, neither should be ignored if one is seeking to understand the way in which human beings arrive at some degree of social order. (shrink)

Within analytic philosophy, the existence of collective knowledge has been motivated by means of two apparently distinct, and in direct competition with one another, theoretical approaches: (i) the commitment model and (ii) the distributed model. This paper agues, however, that to fully account for collaborative knowledge—i.e., a special kind of collective knowledge—both models are required. In other words, there is at least one kind of collective knowledge, the account of which requires treating the two models not as competitors but as (...) complementary to each other. If that’s correct, not only can we gain a deeper understanding of the specifics surrounding collaborative knowledge but also a clearer picture of the broader debate surrounding collective knowledge. (shrink)

There are modes of presentation of a person in thought corresponding to the first and third person pronouns. This paper proposes that there is also thought involving a second person mode of presentation of another, which might be expressed by an utterance involving ‘you’, but need not be expressed linguistically. It suggests that co-operative activity is the locus for such thought. First person thought is distinctive in how it supplies reasons for the subject to act. In co-operative action there is (...) first person plural intending and judging. So there is a way of thinking of another, when openly co-operating with him or her, which plays the distinctive role of giving reason for contribution to the co-operative activity. In slogan form, ‘you’ is ‘we minus I’. The way children learn to use second and third person pronouns is naturally explained on this view. Contrasting less sophisticated kinds of co-operative activity with more sophisticated forms, and considering some issues about common knowledge and commo.. (shrink)

This article presents a community-based account of salience as an alternative and a complement to the ‘natural salience’ approach which is endorsed by almost all game theorists who use this concept. While in the naturalistic approach, salience is understood as an objective and natural property of some entities, the community-based account claims that salience is a function of community membership. Building on David Lewis’s theory of common knowledge and on some of its recent refined accounts, I suggest that salience acts (...) as a correlating device in a correlated equilibrium. What is constitutive of salience is common understanding, the fact that agents have common knowledge that they share the same modes of reasoning with respect to a well-identified set of events. I argue that the basis for common understanding is community membership. The relevance of this account stems from the fact that it answers the objection that salience is either unnecessary or unable to account for coordination between rational agents. (shrink)

This volume adds a largely redundant stratum to Searle’s effort to develop a systematic social ontology, a theory of the nature, kind or status of social entities. This has been one of Searle’s main concerns in the last two decades, and, while this thread of his work stands on the views about language and mind he developed since the 1960s, we can safely trace its origins to a paper published in 1990, “Collective Intentions and Actions” (Searle, 1990/2002). Beyond this early (...) reference, the book is a sequel to The Construction of Social Reality (Searle, 1995), and it builds on the texts written to complete that book or in response to criticism. (shrink)

Vladimir Krstić (2023) argues that some putative counterexamples to the definition of lying in terms of an intention to deceive are not genuine counterexamples. He suggests that the agents in these cases have an ‘oblique intention’ to deceive. I argue that Krstić is incorrect about both these cases and the very notion of oblique intention.

There are several ways to quantify over public announcements. The most notable are reflected in arbitrary, group, and coalition announcement logics, with the latter being the least studied so far. In the present work, we consider coalition announcements through the lens of group announcements, and provide a complete axiomatisation of a logic with coalition announcements. To achieve this, we employ a generalisation of group announcements. Moreover, we study some logical properties of both coalition and group announcements that have not been (...) studied before. (shrink)