The papers collected in this volume exemplify some of the trends in current approaches to logic, language and computation. Written by authors with varied academic backgrounds, the contributions are intended for an interdisciplinary audience. The first part of this volume addresses issues relevant for multi-agent systems: reasoning with incomplete information, reasoning about knowledge and beliefs, and reasoning about games. Proofs as formal objects form the subject of Part II. Topics covered include: contributions on logical frameworks, linear logic, and different (...) approaches to formalized reasoning. Part III focuses on representations and formal methods in linguistic theory, addressing the areas of comparative and temporal expressions, modal subordination, and compositionality. (shrink)

The analysis of belief ascriptions has been a central problem in philosophy for the past one hundred years. Working within a direct reference framework, the dissertation begins with a look at several of the most influential analyses of belief ascriptions over this period of time. It is argued that they all suffer from a common defect; they ignore important contextual factors which affect how belief ascriptions are interpreted. To repair this defect it is necessary to enter the (...) realm of pragmatics--the study of linguistic acts and the contexts in which they are performed. It is argued that the information conveyed by an utterance may differ significantly from its literal content. "Information conveyed" is a purely pragmatic concept; an utterance may potentially convey different information for every one of its interpreters, even though it has only one literal content. ;Following the development of the literal content/information conveyed distinction, three recent pragmatic theories of belief ascription are examined. Counterexamples are presented to each of these in turn. Finally, a theory of belief ascription is presented which is based on the literal content/information conveyed distinction. This new theory fits all of the examples that gave the other theories trouble. (shrink)

On first reading Les Mots, it was as much of a surprise to note that references to religion and belief were both so frequent and so central to Sartre's unconventional autobiography as it was to learn that the famous Christian missionary Albert Schweitzer was his cousin. Further readings and analyses have reinforced my view that the language of belief plays a critical part in the text. These questions of belief and the references to religion that appear (...) frequently in Les Mots have received less attention. It could be said that these references are merely illustrative of Sartre's attempt to explain himself to himself and to us, and function as any metaphor would. But such a suggestion would fail to account for the many references to religion and belief and to explain why they are so tightly interlinked. We will argue that closer attention to these subjects provides significant insight into the work. Sartre, it would appear, uses a religious template, rather than an existentialist or a Marxist one, to understand his life's project, his past and his present. We will therefore investigate the nature of this use of the language of belief as a religious template and evaluate its significance. (shrink)

On first reading Les Mots, it was as much of a surprise to note that references to religion and belief were both so frequent and so central to Sartre's unconventional autobiography as it was to learn that the famous Christian missionary Albert Schweitzer was his cousin. Further readings and analyses have reinforced my view that the language of belief plays a critical part in the text. These questions of belief and the references to religion that appear (...) frequently in Les Mots have received less attention. It could be said that these references are merely illustrative of Sartre's attempt to explain himself to himself and to us, and function as any metaphor would. But such a suggestion would fail to account for the many references to religion and belief and to explain why they are so tightly interlinked. We will argue that closer attention to these subjects provides significant insight into the work. Sartre, it would appear, uses a religious template, rather than an existentialist or a Marxist one, to understand his life's project, his past and his present. We will therefore investigate the nature of this use of the language of belief as a religious template and evaluate its significance. (shrink)

Analytical tools that give precision to the concept of "independence of syntax" are developed in the form of a series of substitutivity principles. These principles are applied in a study of the rôle of language in belief revision theory. It is shown that sets of sentences can be used in models of belief revision to convey more information than what is conveyed by the combined propositional contents of the respective sets. It is argued that it would be (...) unwise to programmatically restrain the use of sets of sentences to that of representing propositional contents. Instead, the expressive power of language should be used as fully as possible. Therefore, syntax-independence should not be seen as a criterion of adequacy for language-based models of information-processing, but rather as a property that emerges from some but not all the idealization processes through which such models are constructed. (shrink)

Analytical tools that give precision to the concept of "independence of syntax" are developed in the form of a series of substitutivity principles. These principles are applied in a study of the rôle of language in belief revision theory. It is shown that sets of sentences can be used in models of belief revision to convey more information than what is conveyed by the combined propositional contents of the respective sets. It is argued that it would be (...) unwise to programmatically restrain the use of sets of sentences to that of representing propositional contents. Instead, the expressive power of language should be used as fully as possible. Therefore, syntax-independence should not be seen as a criterion of adequacy for language-based models of information-processing, but rather as a property that emerges from some but not all the idealization processes through which such models are constructed. (shrink)

This paper attempts to revisit how ‘acquaintance’ could bring about belief and how belief becomes knowledge in our language system due to the credential undertaking of truth, justification, evidence, and causal or conceptual preservation. My quest in this paper is to interrogate belief and the cessation of belief (I call this the ‘death of belief’) from the perspective of the doxastic approach of externalism and internalism in the philosophy of language and philosophy of (...) mind. I will attempt to make sense of the nominal appeal (an approach that conserves the process of continuing belief through evidence and conceptualization) to both of these ideas in a sophisticated manner. The linguistic form of using words seems allied to the context sensitivity of the speakers involved in social practices. A tripartite structure pivots the model of linguistic belief, where minds are causally entrenched in a world that stimulates conceptual or internal states, representing how objectivity works. The entanglements of concepts with pictures hinge on conceptual prerequisites to impact the world. (shrink)

The present stage of development of the philosophy of language is marked by the joining of efforts of philosophers, logicians, and linguists for solution of one of the most difficult problems posed by the progress of scientific knowledge - the problem of modeling the aspect of meaning, of semantics, of natural language. The solution of this problem governs not only the building of a general theory of language, not only scientific explanation of the phenomenon of the understanding (...) of language and solution of numerous problems of practical importance with respect to automatic language processing, but also the defining of the place and function of language in the process of cognition and understanding of the world, a matter that is fundamental to methodology. (shrink)

In this book, psychologists and philosophers describe and discuss a range of case studies of delusional beliefs, drawing out general lessons both for the cognitive architecture of the mind and for the notion of rationality, and exploring connections between the delusional beliefs that occur in schizophrenia and the flawed understanding of beliefs that is characteristic of autism.

Speaking with conversational AIs, technologies whose interfaces enable human-like interaction based on natural language, has become a common phenomenon. During these interactions, people form their beliefs due to the say-so of conversational AIs. In this paper, I consider, and then reject, the concepts of testimony-based beliefs and instrument-based beliefs as suitable for analysis of beliefs acquired from these technologies. I argue that the concept of instrument-based beliefs acknowledges the non-human agency of the source of the belief. However, the (...) analysis focuses on perceiving signs and indicators rather than content expressed in natural language. At the same time, the concept of testimony-based beliefs does refer to natural language propositions, but there is an underlying assumption that the agency of the testifier is human. To fill the lacuna of analyzing belief acquisition from conversational AIs, I suggest a third concept: technology-based beliefs. It acknowledges the non-human agency-status of the originator of the belief. Concurrently, the focus of analysis is on the propositional content that forms the belief. Filling the lacuna enables analysis that considers epistemic, ethical, and social issues of conversational AIs without excluding propositional content or compromising accepted assumptions about the agency of technologies. (shrink)

A compact, coherent introduction to the study of rational belief, this text provides points of entry to such areas of philosophy as theory of knowledge, methodology of science, and philosophy of language. The book is accessible to all undergraduates and presupposes no philosophical training.

Most of the literature on doxastic voluntarism has concentrated on the question of the voluntariness of belief and the issue of how our actual or possible control of our beliefs bears on our justification for holding them and on how, in the light of this control, our intellectual character should be assessed. This paper largely concerns a related question on which less philosophical work has been done: the voluntariness of the grounding of belief and the bearing of various (...) views about this matter on justification, knowledge, and intellectual virtue. In part, my concern is the nature and extent of our voluntary control over our responses to reasons for believing—or over what we take to be such reasons. This paper provides a partial account of such control and, on the basis of the account, will clarify the criteria for appraising intellectual virtue. (shrink)

Many philosophers think that being in an intentional state is a matter of being related to a sentence in a mental language-a 'Language of Thought' (see especially Fodor 1975, 1987 Appendix; Field 1978). According to this view-which I shall call 'the LT hypothesis'-when anyone has a belief or a desire or a hope with a certain content, they have a sentence of this language, with that content, 'written' in their heads. The claim is meant quite literally: (...) the mental representations that make up the items of this language have semantic and syntactic properties. This is why, according to this view, cognitive psychology does, and should, treat that part of the mind which deals with intentional states as a semantic and a syntactic 'engine'. (shrink)

Réseau LACTO (Langage, Argumentation et Cognition dans les Traditions Orales) Quatrième Rencontre du Réseau Lacto CELHTO, bureau de l'Union Africaine, Niamey, Niger, du 22 au 25 septembre 2015 : JEU ET ORALITE DANS LES SOCIETES A TRADITION ORALE According to the main stream approaches to epistemic notions, knowledge and belief are understood as propositional operators. Thus, • Gildas believes that there is a witch in his village is understood as expressing a proposition. Moreover, • Gildas knows that Gödel proved (...) the completeness of first-order logic, expresses a proposition too. The difference between both is that a belief-proposition can be true if it is " factually " false: in our case the proposition can be true in relation to Gildas's belief, that is, despite the fact that there is no witch in his village. Furthermore, assuming that there is not witch in his village, the following proposition is false • Gildas knows that there is a witch in his village. If the latter is false, from the point of view of the mainstream, there was not knowledge at all, rather it was from the start a belief that has not been verified. 1 The present paper is part of an ongoing project in the context of the research-program Argumentation, Decision, Action (ADA) and the project Logique, Argumentation et Cognition dans les Traditions Orales (LACTO) both supported by the Maison Européenne des Sciences de l' Homme et de la Société-USR 318 and by the laboratory UMR 8163: STL. (shrink)

In this book, Brit Brogaard defends the view that visual experience is like belief in having a representational content. Her defense differs from most previous defenses of this view in that it begins by looking at the language of ordinary speech. She provides a linguistic analysis of what we say when we say that things look a certain way or that the world appears to us to be a certain way. She then argues that this analysis can be (...) used to argue for the view that visual experience has a representation content that mediates between you and the world when you visually perceive. (shrink)

It has been argued that belief in free will is socially consequential and psychologically universal. In this paper we look at the folk concept of free will and its critical assessment in the context of recent psychological research. Is there a widespread consensus about the conceptual content of free will? We compared English “free will” with its lexical equivalents in Lithuanian, Hindi, Chinese and Mongolian languages and found that unlike Lithuanian, Chinese, Hindi and Mongolian lexical expressions of “free will” (...) do not refer to the same concept free will. What kind people have been studied so far? A review of papers indicate that, overall, 91% of participants in studies on belief in free will were WEIRD. Thus, given that free will has no cross-culturally universal conceptual content and that most of the reviewed studies were based on WEIRD samples, belief in free will is not a psychological universal. (shrink)

In this article we strive to provide a detailed and principled analysis of the role of beliefs in goal processing—that is, the cognitive transition that leads from a mere desire to a proper intention. The resulting model of belief-based goal processing has also relevant consequences for the analysis of intentions, and constitutes the necessary core of a constructive theory of intentions, i.e. a framework that not only analyzes what an intention is, but also explains how it becomes what it (...) is. We discuss similarities and differences between our approach and other standard accounts of intention, in particular Bratman’s planning theory. The aim here is to question and refine the conceptual foundations of many theories of intentional action: as a consequence, although our analysis is not formal in itself, it is ultimately meant to have deep consequences for formal models of intentional agency. (shrink)

Various philosophers authors have argued—on the basis of powerful examples—that we can have compelling moral or practical reasons to believe, even when the evidence suggests otherwise. This paper explores an alternative story, which still aims to respect widely shared intuitions about the motivating examples. Specifically, the paper proposes that what is at stake in these cases is not belief, but rather acceptance—an attitude classically characterized as taking a proposition as a premise in practical deliberation and action. I suggest that (...) acceptance’s theoretical usefulness in the ethics of belief has been hidden by its psychological obscurity. I thus aim to develop an empirically adequate and mechanistically specific psychological profile of acceptance. I characterize acceptance as centrally involving a cognitive gating function, in which we prevent a target belief state from having its characteristic downstream effects on reasoning, cognition, and action, and restructure those downstream processes. I then argue that there is substantial empirical support for the existence of the cognitive mechanisms needed to instantiate this view, coming from the science of emotion regulation. I argue that acceptance involves deploying the same mechanisms used in emotional response modulation to belief states: acceptance is doxastic response modulation. I then propose that having a better understanding of the psychological profile of acceptance leaves us better positioned to appreciate its potential usefulness for making progress on various puzzles within the ethics of belief. (shrink)

Common sense explanations of human action are often framed in terms of an agent's beliefs and desires. Recent widely received views also take believing and desiring as attitudes of an agent to linguistic or quasi‐linguistic entities. It is here claimed that such a narrow view of cognitive attitudes is not supportable, since even among lingual non‐verbal responses are often overriding evidence for belief and desire, even where they run counter to sincere verbal assents. The view is also curiously non (...) naturalistic in that it disallows ascribing beliefs and desires altogether to non‐lingual and pre‐lingual. In the present paper a “common sense” explanation of action in accordance with the triad Desire, Belief, Action, is seen as a useful phenomenological “theory” provided that language centrality is not taken as essential. (shrink)

The present paper aims at a synthesis of belief revision theory with the Sneed formalism known as the structuralist theory of science. This synthesis is brought about by a dynamisation of classical structuralism, with an abductive inference rule and base generated revisions in the style of Rott (2001). The formalism of prioritised default logic (PDL) serves as the medium of the synthesis. Why seek to integrate the Sneed formalism into belief revision theory? With the hybrid system of the (...) present investigation, a substantial simplification of the ranking information that is necessary to define revisions and contractions uniquely is achieved. This system is, furthermore, expressive enough to capture complex and non-trivial scientific examples. It is thus closely related to a novel research area within belief revision theory which addresses the dynamics of scientific knowledge. (shrink)

It is shown how the discussion of the semantics of sentences attributing belief, central to the philosophy of language since Frege, may benefit from consideration of pragmatic features of the context of utterance. ;The dissertation begins with a historical introduction to the problem of substitutivity in belief contexts. Traditional solutions advanced by Frege, Russell, and Carnap are reviewed, along with traditional objections to such solutions. It is then suggested that the traditional Quinian approach of declaring belief (...) ascriptions semantically ambiguous might be avoided by appeal to pragmatic considerations. ;Radically divergent appeals to pragmatics are discussed. It is suggested, on one hand, how theories of reference associated with philosophers such as Kripke and Kaplan can benefit from pragmatic analysis, as it is demonstrated that substitution failure in belief ascriptions may be due to pragmatic rather than semantical factors. This is argued for in three ways: it is shown how the result of unacceptable substitution may be pragmatically ambiguous, insufficiently informative, or simply misleading. ;It is also suggested, on the other hand, how some followers of Frege may similarly argue that substitution success may be due to pragmatic rather than semantical factors. That is, it is shown how those who maintain that substitution in belief contexts is not truth-preserving and, roughly, that a sentence attributing a belief to someone is true only if the person would assent to it, can argue that our occasional inclination to accept a belief report to which the believer would not assent may be due to features of the sentence's utterance, rather than its truth conditions. ;After brief speculation on the ramifications of these pragmatic analyses for the semantics of belief, there is a discussion of the principle methodological issues raised by pragmatic analyses, with special attention to the distinction between pragmatic import and semantical meaning. Further discussion of pragmatics comes in the appendix, containing a critical review of various conceptions of pragmatics and of Grice's theory of conversation. (shrink)

I outline the debate in metaphysics between those who believe time is tensed and those who believe it is tenseless. I describe the terms in which this debate has been carried out, and the significance to it of ordinary tensed language and widespread common sense beliefs that time is tensed. I then outline a case for thinking that our intuitive beliefs about tense constitute an Adaptive Imaginary Representation (Wilson, in Biol Philos 5:37–62, 1990; Wilson, in Biol Philos 10:77–97, 1995). (...) I also outline a case for thinking that our ordinary tensed beliefs and tensed language owe their tensed nature to its being adaptive to adopt a temporally self-locating perspective on reality. If these conclusions are right, then common sense intuitions and temporal language will be utterly misleading guides to the nature of temporal reality. (shrink)

According to the mental continuity claim (MCC), human mental faculties are physical and beneficial to human survival, so they must have evolved gradually from ancestral forms and we should expect to see their precursors across species. Materialism of mind coupled with Darwin’s evolutionary theory leads directly to such claims and even today arguments for animal mental properties are often presented with the MCC as a premise. However, the MCC has been often challenged among contemporary scholars. It is usually argued that (...) only humans use language and that language as such has no precursors in the animal kingdom. Moreover, language is quite often understood as a necessary tool for having representations and forming beliefs. As a consequence, by lacking language animals could not have developed representational systems or beliefs. In response to these worries, we aim to mount a limited defense of the MCC as an empirical hypothesis. First, we will provide a short historical overview of the origins of the MCC and examine some of the motives behind traditional arguments for and against it. Second, we will focus on one particular question, namely whether language as such is necessary for having beliefs. Our goal is to show that there is little reason to think language is necessary for belief. In doing so, we will challenge a view of belief that is widely accepted by those working in animal cognition, namely representational belief, and we will argue that if belief is non-representational, then different research questions and methods are required. We will conclude with an argument that to study the evolution of belief across species, it is essential to begin the study of subjects in their social and ecological environment rather than in contexts that are not ecologically valid along the social and ecological dimensions. Thus, rather than serving as a premise in an argument 3 in favor of animal minds, the MCC can only be defended by empirical investigation, but importantly, empirical investigation of the right sort.. (shrink)

Davidson, Rorty, and Rosenberg each reject, for similar reasons, the idea that truth is the aim of belief and the goal of inquiry. Rosenberg provides the most explicit and compelling argument for this provocative view. Here, with a focus on this argument, I suggest that this view is a mistake, but not for the reasons some might think. In my view, we can view truth as a constitutive aim of belief even if not a regulative goal of inquiry, (...) if we adopt a Sellarsian view of the ought-to-be’s of belief. Along the way, I suggest that many aspects of Rosenberg’s (unfortunately under-appreciated) epistemology are in fact defensible and are independent of his strong denial of truth's role in constraining epistemic practices. (shrink)

This edited volume presents new lines of research dealing with the language of thought and its philosophical implications in the time of Ockham. It features more than 20 essays that also serve as a tribute to the ground-breaking work of a leading expert in late medieval philosophy: Claude Panaccio. Coverage addresses topics in the philosophy of mind and cognition (externalism, mental causation, resemblance, habits, sensory awareness, the psychology, illusion, representationalism), concepts (universal, transcendental, identity, syncategorematic), logic and language (definitions, (...) syllogisms, modality, supposition, obligationes, et cetera), action theory (belief, will, action), and more. A distinctive feature of this work is that it brings together contributions in both French and English, the two major research languages today on the main theme in question. It unites the most renowned specialists in the field as well as many of Claude Panaccio's former students who have engaged with his work over the years. In furthering this dialogue, the essays render key topics in fourteenth-century thought accessible to the contemporary philosophical community without being anachronistic or insensitive to the particularities of the medieval context. As a result, this book will appeal to a general population of philosophers and historians of philosophy with an interest in logic, philosophy of language, philosophy of mind, and metaphysics. (shrink)

Different religious traditions offer apparently very different pictures of the world. How are we to make sense of this radical diversity of religious belief? In this book, Professor Godlove argues that religions are alternative conceptual frameworks, the categories of which organise experience in diverse ways. He traces the history of this idea from Kant to Durkheim, and then proceeds to discuss two constraints on the diversity of all human judgment and belief: first that human experience is made possible (...) by shared, a priori rules, and second, that as language-users we must presuppose that we hold the vast bulk of our beliefs in common. Given these unavoidable constraints, it is clear how religions may offer encompassing symbolic systems that often diverge dramatically from one another. 'An original and brilliant critique of Durkheim and Kant from within the framework of Davidson's semantic theory. This book is required reading for anyone interested in the academic study of religion, and the problems of relativism and the diversity of belief.' -- Hans H. Penner, Dartmouth CollegeDifferent religious traditions offer apparently very different pictures of the world. How are we to make sense of this radical diversity of religious belief? In this book, Professor Godlove argues that religions are alternative conceptual frameworks, the categories of which organise experience in diverse ways. He traces the history of this idea from Kant to Durkheim, and then proceeds to discuss two constraints on the diversity of all human judgment and belief: first that human experience is made possible by shared, a priori rules, and second, that as language-users we must presuppose that we hold the vast bulk of our beliefs in common. Given these unavoidable constraints, it is clear how religions may offer encompassing symbolic systems that often diverge dramatically from one another. 'An original and brilliant critique of Durkheim and Kant from within the framework of Davidson's semantic theory. This book is required reading for anyone interested in the academic study of religion, and the problems of relativism and the diversity of belief.' -- Hans H. Penner, Dartmouth College. (shrink)

Using probability functions defined over a simple language as models of states of belief, my goal in this article has been to analyse contractions and revisions of beliefs. My first strategy was to formulate postulates for these processes. Close parallels between the postulates for contractions and the postulates for revisions have been established - the results in Section 5 show that contractions and revisions are interchangeable. As a second strategy, some suggestions for more or less explicit constructive definitions (...) of the revision process (and indirectly also of the contraction process) were then presented. However, the results in Section 6 are less conclusive than in the earlier ones. This problem area still awaits further development. (shrink)

nated discussion of the semantics of such verbs. I will call this view.

Learning the unique linguistic forms and structures that construct and communicate scientific principles, knowledge, and beliefs is important for developing students’ disciplinary literacy. The use of scientific language is apparent in the texts that scientists produce to communicate their findings to other scientists—the research articles. Texts are underused in the science classroom and the texts that students do read often do not reflect the core attributes of authentic scientific reasoning. Adapted primary literature refers to an educational genre that enables (...) the use of scientific articles in high school. In the adaptation process, the language of the article is changed to make it more accessible for high school students. Here, we present a systemic functional linguistics analysis of an APL article compared to the original research article and to a popular article. The three texts were systematically scanned and compared for specific lexicogrammatical items that characterize five linguistic features of scientific writing: informational density, abstraction, technicality, authoritativeness, and hedging. We found that the adaptation process lowered the lexical complexity, while retaining the authenticity of the scientific writing. APL articles, as suggested by the linguistic analysis presented here, may serve as models of scientific reasoning and communication and may promote students’ language awareness and disciplinary literacy. We suggest using APL articles as an apprenticeship genre, for learning about the unique features of authentic scientific texts, and the reasoning that is reflected in the way the articles are written. (shrink)

This book provides a formal ontology of senses and the belief-relation that grounds the distinction between de dicto, de re, and de se beliefs as well as the opacity of belief reports. According to this ontology, the relata of the belief-relation are an agent and a special sort of object-dependent sense (a "thought-content"), the latter being an "abstract" property encoding various syntactic and semantic constraints on sentences of a language of thought. One bears the belief-relation (...) to a thought-content T just in case one (is disposed as one who) inwardly affirms a certain sentence S of one’s language of thought that satisfies what T encodes, which in turn requires that S’s non-logical parts stand in appropriate semantical relations to items specified by T. Since these items may include other senses as well as ordinary objects, beliefs of arbitrary complexity are automatically accommodated. Within the framework of the formal ontology, a context-dependent compositional semantics is then provided for a fragment of regimented English capable of formulating ascriptions of belief—a semantics that treats substitutional opacity as a genuine semantic datum. Finally, the resulting picture of belief and its attribution is defended by showing how it solves standard puzzles, avoids objections to rival accounts, and satisfies certain adequacy conditions not fulfilled by traditional theories. Along the way, clarification and defense is offered for the ingredient conception of object-dependent senses, and it is shown how adoption of the language of thought hypothesis permits Bertrand Russell’s obscure doctrine of logical forms to be understood in a way that not only vindicates his Multiple Relation theory of de re belief but also reveals the connection between these logical forms and thought-contents. (shrink)

Epistemology has always been concerned with mental states, especially doxastic states such as belief, suspension of judgment, and the like. A significant part of epistemology is the attempt to evaluate, appraise, or criticize alternative procedures for the formation of belief and other doxastic attitudes. In addressing itself to doxastic states, epistemology has usually employed our everyday mental concepts and language. Occasionally it has tried to systematize or precise these mental categories, e.g., by introducing the notion of subjective (...) probabilities. But this is a minor refinement in our intuitive notion of degrees of confidence. What epistemology has not done—at least 20th century analytic epistemology hasn’t done it—is to seek help from experimental psychology in choosing its doxastic categories. Analytic epistemology has generally assumed that doxastic descriptions generated by casual and introspective thought are adequate for its purposes. (shrink)

Self-referential sentences have troubled our understanding of language for centuries. The most famous self-referential sentence is probably the Liar, a sentence that says of itself that it is false. The Liar Paradox has encouraged many philosophers to establish theories of truth that manage to give a proper account of the truth predicate in a formal language. Kripke’s Fixed Point Theory from 1975 is one famous example of such a formal theory of truth that aims at giving a plausible (...) notion of truth by allowing truth value gaps. However, not only the concept of truth gives rise to paradoxes. A syntactical treatment of epistemic notions like belief and knowledge leads to contradictions that very much resemble the Liar Paradox. Therefore, it seems to be fruitful to apply the established theories of truth to epistemic concepts. In this paper, I will present one such attempt of solving the epistemic paradoxes: I adapt Kripke’s Fixed Point Theory and interpret truth, knowledge and belief within the framework of a partial logic. Thereby I find not only the fixed point of truth but also the fixed points of knowledge and belief. In this fixed point, the predicates of truth, belief and knowledge find their definite interpretation and the paradoxes are avoided. (shrink)

This paper examines the adequacy of commitment change, as a measure of the successful resolution of a difference of opinion. I argue that differences of opinion are only effectively resolved if commitments undertaken in argumentation survive beyond its conclusion and go on to govern an arguer’s actions in everyday life, e.g., by serving as premises in her practical reasoning. Yet this occurs, I maintain, only when an arguer’s beliefs are changed, not merely her commitments.

We consider extending the modal logic KD45, commonly taken as the baseline system for belief, with propositional quantifiers that can be used to formalize natural language sentences such as “everything I believe is true” or “there is something that I neither believe nor disbelieve.” Our main results are axiomatizations of the logics with propositional quantifiers of natural classes of complete Boolean algebras with an operator validating KD45. Among them is the class of complete, atomic, and completely multiplicative BAOs (...) validating KD45. Hence, by duality, we also cover the usual method of adding propositional quantifiers to normal modal logics by considering their classes of Kripke frames. In addition, we obtain decidability for all the concrete logics we discuss. (shrink)

Nihilism is the thesis that no composite objects exist. Some ontologists have advocated abandoning nihilism in favor of deep nihilism, the thesis that composites do not existO, where to existO is to be in the domain of the most fundamental quantifier. By shifting from an existential to an existentialO thesis, the deep nihilist seems to secure all the benefits of a composite-free ontology without running afoul of ordinary belief in the existence of composites. I argue that, while there are (...) well-known reasons for accepting nihilism, there appears to be no reason at all to accept deep nihilism. In particular, deep nihilism draws no support either from the usual arguments for nihilism or from considerations of parsimony. (shrink)

Problem of epistemic activity and their relationship with language is very well known in philosophy. Undertaking this challenge in this article we shall present some logical constructions apparent in these issues. More precisely we want to describe some difficulties of formal reconstruction of the notion of belief and utterance and try to find broader perspective appointed by notion of trust. To realize this goals article shows how non-formal assumption about doxa affects on its formal construction. Then, logic of (...) utterances—mainly based on Conversational Implicatures theory—and its relation to doxastic systems is discussed and, finally, article shows that more accurate description of these two notions needs broader perspective created by BIT system proposed by Ch-J. Liau. (shrink)