In this paper I focus on a recently discussed phenomenon illustrated by sentences containing predicates of taste: the phenomenon of " perspectival plurality " , whereby sentences containing two or more predicates of taste have readings according to which each predicate pertains to a different perspective. This phenomenon has been shown to be problematic for (at least certain versions of) relativism. My main aim is to further the discussion by showing that the phenomenon extends to other perspectival expressions than predicates (...) of taste and by proposing a general solution to the problem raised by it on behalf of the relativist. The core claim of the solution (" multiple indexing ") is that utterances of sentences containing perspectival expressions should be evaluated with respect to (possibly infinite) sequences of perspective parameters. (shrink)

RésuméPaul Boghossian soutient contre Wittgenstein que le normativisme au sujet de la logique et des mathématiques est incompatible avec le fait de tenir les énoncés logiques et mathématiques pour vrais et que le normativisme entraîne une régression indue. Je soutiens, pour ma part, que le normativisme n'entraîne pas une telle régression, parce que les normes peuvent être implicites et que le normativisme peut bien être «factualiste» si l'on rejette ce que Rockney Jacobsen appelle le «cognitivisme sémantique». Je tiens en outre (...) que la position de Boghossian repose sur la façon trompeuse dont il découpe le terrain conceptuel. (shrink)

What words we use, and what meanings they have, is important. We shouldn't use slurs; we should use 'rape' to include spousal rape (for centuries we didn’t); we should have a word which picks out the sexual harassment suffered by people in the workplace and elsewhere (for centuries we didn’t). Sometimes we need to change the word-meaning pairs in circulation, either by getting rid of the pair completely (slurs), changing the meaning (as we did with 'rape'), or adding brand new (...) word-meaning pairs (as with 'sexual harassment'). A problem, though, is how to do this. One might worry that any attempt to change language in this way will lead to widespread miscommunication and confusion. I argue that this is indeed so, but that's a feature, not a bug of attempting to change word-meaning pairs. The miscommunications and confusion such changes cause can lead us, via a process I call transformative communicative disruption, to reflect on our language and its use, and this can be further, rather than hinder, our goal of improving language. (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 present volume contains a collection of papers presented at the 21st annual meeting “Sinn und Bedeutung” of the Gesellschaft fur Semantik, which was held at the University of Edinburgh on September 4th–6th, 2016. The Sinn und Bedeutung conferences are one of the leading international venues for research in formal semantics.

Skyrms, building on the work of Dretske, has recently developed a novel information-theoretic account of propositional content in simple signalling systems. Information-theoretic accounts of content traditionally struggle to accommodate the possibility of misrepresentation, and I show that Skyrms’s account is no exception. I proceed to argue, however, that a modified version of Skyrms’s account can overcome this problem. On my proposed account, the propositional content of a signal is determined not by the information that it actually carries, but by the (...) information that it would carry at the nearest separating equilibrium of the underlying evolutionary dynamics. I show that this amended account yields reasonable ascriptions of false propositional content in a well-known formal model of the evolution of communication , and close with a discussion of the serious but perhaps not insuperable difficulties we face in applying the account to examples of signalling in the real world. (shrink)

Inscrutability arguments threaten to reduce interpretationist metasemantic theories to absurdity. Can we find some way to block the arguments? A highly influential proposal in this regard is David Lewis’ ‘ eligibility ’ response: some theories are better than others, not because they fit the data better, but because they are framed in terms of more natural properties. The purposes of this paper are to outline the nature of the eligibility proposal, making the case that it is not ad hoc, but (...) instead flows naturally from three independently motivated elements; and to show that severe limitations afflict the proposal. In conclusion, I pick out the element of the eligibility response that is responsible for the limitations: future work in this area should therefore concentrate on amending this aspect of the overall theory. (shrink)

This paper attempts to dissolve an apparent difficulty arising in the philosophy of language as discussed by the Indian Buddhist Madhyamaka school. On the one hand Madhyamaka seems to be claiming that every entity is fundamentally linguistic in nature, on the other hand it also asserts that language does not exist. I argue that the difficulty is to be dissolved by distinguishing two different senses of language appealed to by the Mādhyamikas. They argue that one specific understanding of language is (...) deficient (and that therefore language thus understood does not exist), but this is not the same sense of language according to which everything is linguistic in nature. The apparent contradiction is thereby resolved. (shrink)

According to the two-systems account of mindreading, our mature perspective-taking abilities are subserved by two distinct mindreading systems: a fast but inflexible, “implicit” system, and a flexible but slow “explicit” one. However, the currently available evidence on adult perspective-taking does not support this account. Specifically, both Level-1 and Level-2 perspective-taking show a combination of efficiency and flexibility that is deeply inconsistent with the two-systems architecture. This inconsistency also turns out to have serious consequences for the two-systems framework as a whole, (...) both as an account of our mature mindreading abilities and of the development of those abilities. What emerges from this critique is a conception of context-sensitive, spontaneous mindreading that may provide insight into how mindreading functions in complex social environments. This in turn offers a bulwark against skepticism about the role of mindreading in everyday social cognition. (shrink)

Newcomb’s problem is viewed as a dynamic game with an agent and a superior being as players. Depending on whether or not a risk-neutral agent’s confidence in the superior being, as measured by a subjective probability assigned to the move order, exceeds a threshold or not, one obtains the one-box outcome or the two-box outcome, respectively. The findings are extended to an agent with arbitrary increasing utility, featuring in general two thresholds. All solutions require only minimal assumptions about the being’s (...) payoffs, and the being is always sure to predict the agent’s choice in equilibrium. The relevant Nash equilibria are subgame-perfect, except for risk-seeking agents where for intermediate beliefs, the being may be unable to ensure perfect prediction without relying on noncredible threats. Lastly, analogies of Newcomb’s problem to the commitment problem on a continuum are discussed. (shrink)

Philosophers and social scientists have recently turned to Lewis sender–receiver games to provide an account of how lexical terms can acquire meaning through an evolutionary process. However, the evolution of meaning is contingent on both the particular sender–receiver game played and the choice of evolutionary dynamic. In this paper I explore some differences between models that presume an infinitely large and randomly mixed population and models in which a finite number of agents communicate with their neighbors in a social network. (...) My results show that communication with neighbors is more conducive to the evolution of meaning than communication with strangers. Additionally, I show that the behavior of the system is highly dependent on the topological structure of the social network. I argue that a specific class of networks—small world graphs—is especially conducive to the evolution of meaning. This is because small world graphs have a short characteristic path length while still maintaining a high degree of correlation between neighbors. Since many actual social networks, such as friendship networks and nervous systems, are conjectured to be small world structures, these results indicate that these networks are quite hospitable to the efficient evolution of meaning. (shrink)

Imperatives cannot be true or false, so they are shunned by logicians. And yet imperatives can be combined by logical connectives: "kiss me and hug me" is the conjunction of "kiss me" with "hug me". This example may suggest that declarative and imperative logic are isomorphic: just as the conjunction of two declaratives is true exactly if both conjuncts are true, the conjunction of two imperatives is satisfied exactly if both conjuncts are satisfied—what more is there to say? Much more, (...) I argue. "If you love me, kiss me", a conditional imperative, mixes a declarative antecedent ("you love me") with an imperative consequent ("kiss me"); it is satisfied if you love and kiss me, violated if you love but don't kiss me, and avoided if you don't love me. So we need a logic of three -valued imperatives which mixes declaratives with imperatives. I develop such a logic. (shrink)

In this article it is pointed out what kind of rules for communication and argumentation are required in order to make it possible to resolve disputes in an orderly way. In section 2, Gricean maxims and Searlean speech act conditions are integrated in such a way that five general rules for communication can be formulated. In section 3, starting from Lewis's definition of convention, it is argued that the interactional effect of accepting is conventionally linked with the complex communicative act (...) complex of argumentation. In section 4, the rules for argumentation are placed in a dialogical perspective. (shrink)

The aim of this paper is to clarify what kind of normativity characterizes a convention. First, we argue that conventions have normative consequences because they always involve a form of trust and reliance. We contend that it is by reference to a moral principle impinging on these aspects (i.e. the principle of Reliability) that interpersonal obligations and rights originate from conventional regularities. Second, we argue that the system of mutual expectations presupposed by conventions is a source of agreements. Agreements stemming (...) from conventions are “tacit” in the sense that they are implicated by what agents do (or forbear from doing) and without that any communication between them is necessary. To justify this conclusion, we assume that: (1) there is a salient interpretation, in some contexts, of everyone’s silence as confirmatory of the others’ expectations (an epistemic assumption), and (2) the participating agents share a value of not being motivated by hostile attitudes (a motivational assumption). By clarifying the relation between conventions and agreements, the peculiar normativity of conventions is analyzed. (shrink)

Truth by convention, once thought to be the foundation of a uniquely promising approach to explaining our access to the truth in nonempirical domains, is nowadays widely considered an absurdity. Its fall from grace has been due largely to the influence of an argument that can be sketched as follows: our linguistic conventions have the power to make it the case that a sentence expresses a particular proposition, but they can’t by themselves generate truth; whether a given proposition is true—and (...) so whether the sentence that expresses it is true—is a matter of what the world is like, which means it isn’t a matter of convention alone. The consensus is that this argument is decisive against truth by convention. Strikingly, though, it has rarely been formulated with much precision. Here I provide a new rendering of the argument, one that reveals its structure and makes transparent just what assumptions it requires, and then I assess conventionalists’ prospects for resisting each of those assumptions. I conclude that the consensus is mistaken: contrary to what is almost universally thought, there remains a promising way forward for the conventionalist project. Along the way, I clarify conventionalists’ commitments by thinking about what truth by convention would need to be like in order for conventionalism to do the epistemological work it’s intended to do. (shrink)

Theories of institutions can be classified into two broad approaches: institutions-as-rules and institutions-as-equilibria. According to the first approach, institutions are conceived as rules that guide the actions of individuals engaged in social interactions. On the other hand, the second approach views institutions as behavioral patterns. In order to have a complete picture of institutions, we need to take both approaches into consideration. Individuals construct mental models to produce expectations about institutions, while institutions make individual expectations relatively compatible. The main purpose (...) of this paper is to develop a general framework within which it is possible to analyze coevolution of individual mental models and institutions. (shrink)

This paper proposes a concept of intentional cooperation for mutual benefit. This concept uses a form of team reasoning in which team members aim to achieve common interests, rather than maximising a common utility function, and in which team reasoners can coordinate their behaviour by following pre-existing practices. I argue that a market transaction can express intentions for mutually beneficial cooperation even if, extensionally, participation in the transaction promotes each party’s self-interest.

This paper provides a game-theoretic analysis of contrastive focus, extending insights from recent work on the role of noisy communication in prosodic accent placement to account for focus within sentences, sub-sentential phrases and words. The shared insight behind these models is that languages with prosodic focus marking assign prosodic prominence only within elements which constitute material critical for successful interpretation. We first take care to distinguish the information-structural notion of focus from an ontologically distinct notion of givenness marking, and then (...) outline the core properties of focus. We then introduce a signaling game between a speaker and hearer in which the goal is to transmit semantic content with the smallest signal possible. We apply the Iterated Best Response method of Franke to find equilibrium strategies in this game, where a unique equilibrium strategy in this case picks out the “critical information” of an utterance, which by hypothesis constitutes its focus. We show that iterating this game at different syntactic levels of a sentence makes correct predictions about the role of contrast in determining stress within words and phrases, and can be extended to account for association and second occurrence focus effects. (shrink)

From an evolutionary point of view, the function of moral behaviour may be to secure a good reputation as a co-operator. The best way to do so may be to obey genuine moral motivations. Still, one's moral reputation maybe something too important to be entrusted just to one's moral sense. A robust concern for one's reputation is likely to have evolved too. Here we explore some of the complex relationships between morality and reputation both from an evolutionary and a cognitive (...) point of view. (shrink)

What is the relation between norms (in the sense of ?socially accepted rules?) and conventions? A number of philosophers have suggested that there is some kind of conceptual or constitutive relation between them. Some hold that conventions are or entail special kinds of norms (the ?conventions-as-norms thesis?). Others hold that at least some norms are or entail special kinds of conventions (the ?norms-as-conventions thesis?). We argue that both theses are false. Norms and conventions are crucially different conceptually and functionally in (...) ways that make it the case that it is a serious mistake to try to assimilate them. They are crucially different conceptually in that whereas conventions are not normative and are behaviour dependent and desire dependent, norms are normative, behaviour independent, and desire independent. They are crucially different functionally in that whereas conventions principally serve the function of facilitating coordination, norms principally serve the function of making us accountable to one another. (shrink)

Pre‐play signals that cost nothing are sometimes thought to be of no significance in interactions which are not games of pure common interest. We investigate the effect of pre‐play signals in an evolutionary setting for Assurance, or Stag Hunt, games and for a Bargaining game. The evolutionary game with signals is found to have dramatically different dynamics from the same game without signals. Signals change stability properties of equilibria in the base game, create new polymorphic equilibria, and change the basins (...) of attraction of equilibria in the base game. Signals carry information at equilibrium in the case of the new polymorphic equilibria, but transient information is the basis for large changes in the magnitude of basins of attraction of equilibria in the base game. These phenomena exemplify new and important differences between evolutionary game theory and game theory based on rational choice. (shrink)

Este artículo tiene por objetivo aportar en la explicación de la función que cumplen las subcompetencias cognitivas mindreading y la representación mental en la actividad inferencial y el comportamiento argumentativo. El texto discute varias explicaciones alternativas existente en la literatura filosófica y cognitiva, decantándose por una perspectiva evolutiva cultural que pone el acento en el diseño colectivista. Para este efecto, se aborda el cambio evolutivo de la plasticidad cerebro-mente, se discute el alcance de la hipótesis de la inteligencia social y (...) se confrontan distintas nociones de mindreading. (shrink)

Abstract: I argue that the solution to the Red Hat Problem, a puzzle derived from interactive epistemic logic, requires S5. Interactive epis- temic logic is set out in formal terms, and an attempt to solve the red hat puzzle is made in K, K, and K, each of which fails, showing that a stronger system, K is required.

While most evolutionary scenarios for language see it as a communication system with consequences on the language-ready brain, there are major difficulties for such a view. First, language has a core combination of features—semanticity, discrete infinity, decoupling—that makes it unique among communication systems and that raise deep problems for the view that it evolved for communication. Second, extant models of communication systems—the code model of communication (see Millikan 2005) and the ostensive model of communication (see Scott-Phillips 2015) cannot account for (...) language evolution. I propose an alternative view, according to which language first evolved as a cognitive tool, following Fodor’s (1975, 2008) Language of Thought Hypothesis, and was then expiated (externalized) for communication. On this view, a language-ready brain is a brain profoundly reorganized in terms of connectivity, allowing the human conceptual system to emerge, triggering the emergence of syntax. Language as used in communication inherited its core combination of features from the Language of Thought. (shrink)

Confucianism has attracted some attention in business ethics, in particular as a form of virtue ethics. This paper develops ideas about Confucianism in business ethics by extending discussion about Confucian ideas of ritual. Ritual has figured in literature about organisational culture, but Confucian accounts can offer additional ideas about developing ethically desirable organisational cultures. Confucian ritual practice has diverged from doctrine and from the classical emphasis on requirements for concern and respect as parts of ritual. Despite some differences of emphasis (...) amongst early writers, classical texts like the Analects and Mencius allow for the importance of ritual as opportunity for interpersonal encounter. These are texts that bring out the flexibility and context-sensitivity of ritual, with associated implications about the need for care and attention to other individuals. They eschew ritual as unthinking repetition, in favour of ritual as meaningful expression. The mutual awareness such ritual can engender is an important part of human existence. Such ritual is a means to solving coordination problems through common knowledge, as opposed to unthinking routine. Undue routinisation can be one problem with organisational ritual, while another can be use of ritual as a means of oppressive control. In organisations, ritual should satisfy general requirements of concern and respect, and should maintain opportunities for mutual encounter. The difference between arrangements which do or do not offer such opportunities may suggest lines of development for virtue ethics in business. (shrink)

Traditional mechanistic accounts of language processing derive almost entirely from the study of monologue. Yet, the most natural and basic form of language use is dialogue. As a result, these accounts may only offer limited theories of the mechanisms that underlie language processing in general. We propose a mechanistic account of dialogue, the interactive alignment account, and use it to derive a number of predictions about basic language processes. The account assumes that, in dialogue, the linguistic representations employed by the (...) interlocutors become aligned at many levels, as a result of a largely automatic process. This process greatly simplifies production and comprehension in dialogue. After considering the evidence for the interactive alignment model, we concentrate on three aspects of processing that follow from it. It makes use of a simple interactive inference mechanism, enables the development of local dialogue routines that greatly simplify language processing, and explains the origins of self-monitoring in production. We consider the need for a grammatical framework that is designed to deal with language in dialogue rather than monologue, and discuss a range of implications of the account. Key Words: common ground; dialogue; dialogue routines; language comprehension; language production; monitoring; perception-behavior link. (shrink)

In many contexts, such as business, science and law, it is essential to determine whether a company, a product or a person in fact has the reputation attributed to it, regardless of whether that reputation has been rightly earned. In this paper I offer two necessary and jointly sufficient conditions for the attribution of a reputation to a subject within a social group. The first one concerns the way in which reputational information is spread among the members of the relevant (...) social group; the second is the existence, in most members of the group, of a disposition to interpret and evaluate a reputational object in a manner molded by reputational information. Reputational claims generate expectations that are tested every time a member of the group comes in contact with the reputational object. In many cases, the preferential search for behavioral evidence consistent with those expectations will result in a distorted evaluation of the reputational object. (shrink)

I argue that analyses of various kinds of cooperation will benefit from an account of the cognitive and communicative functions required for the cooperation. In particular, I focus on the role of intersubjectivity , which has not been sufficiently considered in game theory. Intersubjectivity will here be divided into representing the emotions, desires, attention, intentions, and beliefs of others. I then analyze some kinds of cooperation—reciprocal altruism, indirect reciprocity, cooperation on future goals, and conventions—with respect to their cognitive and communicative (...) prerequisites. It is argued that uniquely human forms of cooperation depend on advanced forms of intersubjectivity. (shrink)

Here I explore the prospects for fictionalism about the mental, modeled after fictionalism about possible worlds. Mental fictionalism holds that the mental states posited by folk psychology do not exist, yet that some sentences of folk psychological discourse are true. This is accomplished by construing truths of folk psychology as “truths according to the mentalistic fiction.” After formulating the view, I identify five ways that the view appears self-refuting. Moreover, I argue that this cannot be fixed by semantic ascent or (...) by a kind of primitivism. Even so, I also show that the “self-refutation” charges are subtly question-begging. Nevertheless, the reply reveals that a mental fictionalist ought to be a kind of quietist. (shrink)

1. I have fond memories of the Linguistic Society of America meeting in New Orleans just after Christmas in 1988, the last time I was able to see all my humanist friends from graduate school who were attending the concurrent meeting of the MLA. Shortly after that, the LSA decided to forego the company of humanists and assemble by itself during the first week of January. It's hard to fault the decision. Over and above the obvious practical advantages, like not (...) having to wait in line for forty-five minutes outside popular restaurants, the groups had been growing apart intellectually for some time. Few linguists bothered to cross town for MLA sessions on topics like onomastics, English usage, and the history of lexicography. Nor for that matter were those sessions drawing many MLA attendees, either. Literary people didn't seem to be much interested in language study anymore; what filled their ballrooms now were the sessions on deconstruction and other poststructuralist enthusiasms. It was like going back for your annual drink with your high-school sweetheart and finding that you had less and less to talk about. They didn't know what subjacency was and we didn't know what alterity was, and neither seemed to care. If you were of a mind to look for milestones, you could take that as the time when linguistic semantics definitively cut itself loose from its philological roots. Like a lot of semanticists, I had mixed feelings about the break. It's undeniable that linguistic semantics couldn't have come of age as an autonomous empirical discipline if it hadn't.. (shrink)

A descriptive norm is a behavioral rule that individuals follow when their empirical expectations of others following the same rule are met. We aim to provide an account of the emergence of descriptive norms by first looking at a simple case, that of the standing ovation. We examine the structure of a standing ovation, and show it can be generalized to describe the emergence of a wide range of descriptive norms.

ABSTRACT This paper aims at examining the way in which Rahel Jaeggi’s conception of forms of life as inert bundles of practices is connected to the problem of the possibility of an immanent critique of life forms, that is, of a kind of analysis that is both internal and transformative. In the first part, my contention will be that understanding practices in terms of conventions makes it difficult to admit of internal criticisms of them. Jaeggi’s account of immanent critique, as (...) argued in the second part, tries to differentiate practices from social conventions by maintaining that transformations of life forms can be seen as the result of episodes of crises ignited by the inability to cope with “second order” problems. I maintain that, unless one is willing to postulate something like an absolute telos dictating the historical sequence that forms of life must follow, the way in which forms of life solve second order problems displays some conventional features preventing any quick assimilation to the paradigm of immanent critique. This circumstance, as argued in the third section of my presentation, poses an obstacle to Jaeggi’s project of an immanent critique of life forms. (shrink)

Following the pioneering work of David Lewis, many philosophers believe that the rationale of following a convention consists in the fact that conventions are solutions to recurrent coordination problems. Margaret Gilbert has criticised this view, offering an alternative account of the nature of conventions and their normative aspect. In this paper I argue that Gilbert's criticism of Lewis and her alternative suggestions rest on serious misunderstandings. As between these two opposed views, Lewis's is closer to the truth, but I argue (...) only with respect to one type of convention. There is another, important type of conventions, whose normativity does not consist in the solution of coordination problems. The validity of conventions constituting (what I call) autonomous practices can only be derived from the values inherent in the practices they constitute and those values cannot be specified independently of the conventions themselves. (shrink)

This article establishes grounds on which attributions of information and encoding in animal signals are warranted. As common interest increases between evolutionary agents, the theoretical approach best suited to describing their interaction shifts from evolutionary game theory to communication theory, which warrants informational language. The take-home positive message is that in cooperative settings, signals can appropriately be described as transmitting encoded information, regardless of the cognitive powers of signalers. The canonical example is the honeybee waggle dance, which is discussed extensively (...) in the second and third sections. The take-home negative message is that signals are not always a consequence of coadaptation. The communication theory approach is just one end of a continuum explored more thoroughly by evolutionary game theory. The fourth and fifth sections explore this wider framework, as well as overturning some widely held misconceptions about information theory. (shrink)

The commonplace view about metaphorical interpretation is that it can be characterized in traditional semantic and pragmatic terms, thereby assimilating metaphor to other familiar uses of language. We will reject this view, and propose in its place the view that, though metaphors can issue in distinctive cognitive and discourse effects, they do so without issuing in metaphorical meaning and truth, and so, without metaphorical communication. Our inspiration derives from Donald Davidson’s critical arguments against metaphorical meaning and Richard Rorty’s exploration of (...) the diverse uses of language. But unlike these authors we ground our discussion squarely in distinctions about causal mechanisms in cooperative activity developed by H.P. Grice and others. (shrink)

Speakers often do not state requests directly but employ innuendos such as Would you like to see my etchings? Though such indirectness seems puzzlingly inefficient, it can be explained by a theory of the strategic speaker, who seeks plausible deniability when he or she is uncertain of whether the hearer is cooperative or antagonistic. A paradigm case is bribing a policeman who may be corrupt or honest: A veiled bribe may be accepted by the former and ignored by the latter. (...) Everyday social interactions can have a similar payoff structure (with emotional rather than legal penalties) whenever a request is implicitly forbidden by the relational model holding between speaker and hearer (e.g., bribing an honest maitre d’, where the reciprocity of the bribe clashes with his authority). Even when a hearer’s willingness is known, indirect speech offers higher-order plausible deniability by preempting certainty, gossip, and common knowledge of the request. In supporting experiments, participants judged the intentions and reactions of characters in scenarios that involved fraught requests varying in politeness and directness. (shrink)

Some people commonly know a proposition just in case they all know it, they all know that they all know it, they all know that they all know that they all know it, and so on. They commonly believe a proposition just in case they all believe it, they all believe that they all believe it, they all believe that they all believe that they all believe it, and so on. A long tradition in economic theory, theoretical computer science, linguistics (...) and philosophy has held that people have some approximation of common knowledge or common belief in a range of circumstances, for example, when they are looking at an object together, or when they have just discussed something explicitly in conversation. In this paper, I argue that people do not have any approximation of common knowledge or common belief in these circumstances. The argument suggests that people never have any approximation of common knowledge or common belief. (shrink)

Some theories of linguistic meaning, such as those of Paul Grice and David Lewis, make appeal to higher–order thoughts: thoughts about thoughts. Because of this, such theories run the risk of being empirically refuted by the existence of speakers who lack, completely or to a high degree, the capacity of thinking about thoughts. Research on autism during the past 15 years provides strong evidence for the existence of such speakers. Some persons with autism have linguistic abilities that qualify them as (...) speakers, but manifest a severely impaired capacity to understand what it is to have beliefs. (shrink)