The distinction between true belief and knowledge is one of the most fundamental in philosophy, and a remarkable effort has been dedicated to formulating the conditions on which true belief constitutes knowledge. For decades, much of this epistemological undertaking has been dominated by a single strategy, referred to here as the modal approach. Shared by many of the most widely influential constraints on knowledge, including the sensitivity, safety, and anti-luck/risk conditions, this approach rests on a key underlying (...) assumption — the modal profiles available to known and unknown beliefs are in some way asymmetrical. The first aim of this paper is to deconstruct this assumption, identifying its plausibility with the way in which epistemologists frequently conceptualize human perceptual systems as excluding certain varieties of close error under conditions conducive to knowledge acquisition. The second aim of this paper is to then argue that a neural phase phenomenon indicates that this conceptualization is quite likely mistaken. This argument builds on the previous introduction of this neural phase to the context of epistemology, expanding the use of neural phase cases beyond relatively narrow questions about epistemic luck to a much more expansive critique of the modal approach as a whole. (shrink)

This paper develops an account of the meaning of `ought', and the distinction between weak necessity modals (`ought', `should') and strong necessity modals (`must', `have to'). I argue that there is nothing specially ``strong'' about strong necessity modals per se: uses of `Must p' predicate the (deontic/epistemic/etc.) necessity of the prejacent p of the actual world (evaluation world). The apparent ``weakness'' of weak necessity modals derives from their bracketing whether the necessity of the prejacent is verified in the (...) actual world. `Ought p' can be accepted without needing to settle that the relevant considerations (norms, expectations, etc.) that actually apply verify the necessity of p. I call the basic account a modal-past approach to the weak/strong necessity modal distinction (for reasons that become evident). Several ways of implementing the approach in the formal semantics/pragmatics are critically examined. The account systematizes a wide range of linguistic phenomena: it generalizes across flavors of modality; it elucidates a special role that weak necessity modals play in discourse and planning; it captures contrasting logical, expressive, and illocutionary properties of weak and strong necessity modals; and it sheds light on how a notion of `ought' is often expressed in other languages. These phenomena have resisted systematic explanation. In closing I briefly consider how linguistic inquiry into differences among necessity modals may improve theorizing on broader philosophical issues. (shrink)

A consequence relation is strongly classical if it has all the theorems and entailments of classical logic as well as the usual meta-rules (such as Conditional Proof). A consequence relation is weakly classical if it has all the theorems and entailments of classical logic but lacks the usual meta-rules. The most familiar example of a weakly classical consequence relation comes from a simple supervaluational approach to modelling vague language. This approach is formally equivalent to an account of logical (...) consequence according to which α1, ..., αn entails β just in case □α1, ..., □αn entails □β in the modal logic S5. This raises a natural question: If we start with a different underlying modal logic, can we generate a strongly classical logic? This paper explores this question. In particular, it discusses four related technical issues: (1) Which base modal logics generate strongly classical logics and which generate weakly classical logics? (2) Which base logics generate themselves? (3) How can we directly characterize the logic generated from a given base logic? (4) Given a logic that can be generated, which base logics generate it? The answers to these questions have philosophical interest. They can help us to determine whether there is a plausible supervaluational approach to modelling vague language that yields the usual meta-rules. They can also help us to determine the feasibility of other philosophical projects that rely on an analogous formalism, such as the project of defining logical consequence in terms of the preservation of an epistemic status. (shrink)

The purpose of this study is to propose new similarity measures namely rough variational coefficient similarity measure under the rough neutrosophic environment. The weighted rough variational coefficient similarity measure has been also defined. The weighted rough variational coefficient similarity measures between the rough ideal alternative and each alternative are xxxxx calculated to find the best alternative. The ranking order of all the alternatives can be determined by using the numerical values of similarity measures. Finally, an illustrative example has been provided (...) to show the effectiveness and validity of the proposed approach. Comparisons of decision results of existing rough similarity measures have been provided. (shrink)

This paper is devoted to present Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method for multi-attribute group decision making under rough neutrosophic environment. The concept of rough neutrosophic set is a powerful mathematical tool to deal with uncertainty, indeterminacy and inconsistency. In this paper, a new approach for multi-attribute group decision making problems is proposed by extending the TOPSIS method under rough neutrosophic environment. Rough neutrosophic set is characterized by the upper and lower approximation operators and (...) the pair of neutrosophic sets that are characterized by truth-membership degree, indeterminacy membership degree, and falsity membership degree. In the decision situation, ratings of alternatives with respect to each attribute are characterized by rough neutrosophic sets that reflect the decision makers’ opinion. Rough neutrosophic weighted averaging operator has been used to aggregate the individual decision maker’s opinion into group opinion for rating the importance of attributes and alternatives. Finally, a numerical example has been provided to demonstrate the applicability and effectiveness of the proposed approach. (shrink)

We present an inferentialist account of the epistemic modal operator might. Our starting point is the bilateralist programme. A bilateralist explains the operator not in terms of the speech act of rejection ; we explain the operator might in terms of weak assertion, a speech act whose existence we argue for on the basis of linguistic evidence. We show that our account of might provides a solution to certain well-known puzzles about the semantics of modal vocabulary whilst (...) retaining classical logic. This demonstrates that an inferentialist approach to meaning can be successfully extended beyond the core logical constants. (shrink)

When it comes to Kripke-style semantics for quantified modal logic, there’s a choice to be made concerning the interpretation of the quantifiers. The simple approach is to let quantifiers range over all possible objects, not just objects existing in the world of evaluation, and use a special predicate to make claims about existence. This is the constant domain approach. The more complicated approach is to assign a domain of objects to each world. This is the varying (...) domain approach. Assuming that all terms denote, the semantics of predication on the constant domain approach is obvious: either the denoted object has the denoted property in the world of evaluation, or it hasn’t. On the varying domain approach, there’s a third possibility: the object in question doesn’t exist. Terms may denote objects not included in the domain of the world of evaluation. The question is whether an atomic formula then should be evaluated as true or false, or if its truth value should be undefined. This question, however, cannot be answered in isolation. The consequences of one’s choice depends on the interpretation of molecular formulas. Should the negation of a formula whose truth value is undefined also be undefined? What about conjunction, universal quantification and necessitation? The main contribution of this paper is to identify two partial semantics for logical operators, a weak and a strong one, which uniquely satisfy a list of reasonable constraints. I also show that, provided that the point of using varying domains is to be able to make certain true claims about existence without using any existence predicate, this result yields two possible partial semantics for quantified modal logic with varying domains. (shrink)

This article aims to develop a Lacanian approach to bioethics. Point of departure is the fact that both psychoanalysis and bioethics are practices of language, combining diagnostics with therapy. Subsequently, I will point out how Lacanian linguistics may help us to elucidate the dynamics of both psychoanalytical and bioethical discourse, using the movie One flew over the Cuckoo’s Nest and Sophocles’ tragedy Antigone as key examples. Next, I will explain the ‘topology’ of the bioethical landscape with the help of (...) Lacan’s three dimensions: the imaginary, the symbolical and the real. This will culminate in an assessment of the dynamics of bioethical discourse with the help of Lacan’s theorem of the four discourses. Bioethics, I will argue, is not a homogeneous discourse. Rather, four modalities of bioethical discourse can be distinguished, all of them displaying specific weaknesses and strengths, opportunities and threats. This will be elucidated with the help of two case studies, namely the debates on human reproductive technologies and on the use of animals as biomedical research models. (shrink)

We consider a version of so called T x W logic for historical necessity in the sense of R.H. Thomason (1984), which is somewhat special in three respects: (i) it is explicitly based on two-dimensional modal logic in the sense of Segerberg (1973); (ii) for reasons of applicability to interesting fields of philosophical logic, it conceives of time as being discrete and finite in the sense of having a beginning and an end; and (iii) it utilizes the technique of (...) systematic frame constants in order to handle the problem of irreflexivity in tense logics, well known since Gabbay (1981). Axiomatizations are given for two infinite hierarchies of two-dimensional modal tense logics, one without and one with the characteristic operators for historical necessity and possibility. Strong and weak completeness results are obtained for both hierarchies as well as a result to the effect that two approaches to their semantics are equivalent, much in the spirit of Di Maio and Zanardo (1996) and von Kutschera (1997). (shrink)

While a much investigated concept because of its importance in shaping human discourse, modality has still not been given an agreed understanding. Using authentic Chinese court judgments in Hong Kong, this paper aims to unravel the complexity of modality as exemplified in its usage in the legal domain. It examines formal, semantic, and functional approaches to modality, showing their weaknesses in identifying and explaining modality in legal discourse. It proposes a socio-semiotic approach as an alternative for giving us a (...) better understanding of modality in respect of its meaning and function in our language as a sign system. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Philosophy, Psychiatry, & Psychology 11.1 (2004) 71-80 [Access article in PDF] Some Reflections on the (Analytic) Philosophical Approach to Delusion Louis A. Sass There are more things in heaven and earth, Horatio, Than are dreamt of in your philosophy." —Hamlet, Act I, Scene 5 The peculiar, often problematic phenome na of psychopathology have been attract ing the attention of analytic philosophers in recent years. The topic of delusion (...) has been a particular draw, with a number of analytic philosophers attempting to use their conceptual tools, usually combined with ideas from cognitive neuroscience, to criticize the traditional understanding and to clarify the nature of this central psychiatric topic. It is useful to have this kind of interdisciplinary dialogue. Indeed, there is good reason to hope that concepts honed in the philosophy of mind and other philosophical subfields will help to sort out our understanding of a phenomenon (or set of phenomena) for which contemporary psychiatric definitions and conceptualizations are clearly inadequate and, in some respects, downright misleading (see Parnas and Sass 2001; Spitzer 1990).1Here, however, I would like to call attention to some weaknesses that, it seems to me, are rather common (I do not say universal) in many analytic philosophical approaches to psychopathology. In my opinion, there is a tendency to formulate issues and arguments in overly polarized, even dichotomous terms, and then to rely too uncritically on these essentialistic formulations in exploring the domain of inquiry. Although this polarizing tendency sometimes has the salutary effect of clarifying conceptual domains, it can, when taken too far, actually hamper our understanding of phenomena that are often fraught with ambiguities and complexities that defy many standard conceptualizations.The relationship between philosophy and psychopathology is obviously a two-way street—we are familiar, for example, with disorders that challenge deep philosophical assumptions about self and mind (e.g., blindsight, split-brain phenomena, perhaps also Dissociative Identity Disorder, and the first rank symptoms of schizophrenia). I am suggesting that, in their work on delusions, philosophers may need to put more emphasis on moving from the natural phenomena [End Page 71] of psychopathology and to the domain of philosophical analysis.I believe that a greater sensitivity to the modes of knowing associated with the phenomenological tradition, and to the forms of conceptual self-critique fostered by Ludwig Wittgenstein, are crucial ingredients for any adequate approach to delusion as well as many other topics in psychopathology. In my opinion, the work of many analytic philosophers interested in psychopathology would be enriched if they spent more time trying to discover and imagine what it might be like to experience certain kinds of abnormal psychiatric conditions, and also speculating about what implications such experiential modalities might have for action and verbal expression. I believe they would also be wise to spend more time questioning, and attempting to transcend, the philosophically derived conceptual distinctions and dichotomies that appear to organize their conceptual universes. Phenomenological imagination and Wittgensteinian critique can show how to move outside the conceptual capsule and into the rich and strange realms of actual experience, both normal and abnormal.So far I have offered only slogans. Let me use the articles by Tim Bayne and Elisabeth Pacherie (2004) and Robert Klee (2004) to flesh out the criticisms I have offered. There is much that is intelligent and much that is worthwhile in both their articles. (For example, I was largely convinced by the criticisms of John Campbell and of Donald Davidson that are central to the articles by Bayne and Pacherie and by Klee, respectively.) Here, however, I will focus only on issues that illustrate the above-mentioned tendencies—tendencies that, in my view, tend to infect even the best writings on the (analytic) philosophy of psychiatry. I will also make some remarks about the works of Campbell and Davidson, the two philosophers criticized in the articles by Bayne and Pacherie and by Klee. Because the article by Eugenie Georgaca (2004) is in a different tradition, I will say only a few words about it at the end. Bayne and Pacherie on the Preservation-Of-meaning... (shrink)

In this paper we show how modal logic can be applied in the axiomatizations of some dynamic ontologies. As an example we consider the case of mereotopology, which is an extension of mereology with some relations of topological nature like contact relation. We show that in the modal extension of mereotopology we may define some new mereological and mereotopological relations with dynamic nature like stable part-of and stable contact. In some sense such “stable” relations can be considered as (...) approximations of the “essential relations” in the domain of mereotopology. (shrink)

In the present paper we examine very weak modal logics C1, D1, E1, S0.5◦, S0.5◦+(D), S0.5 and some of their versions which are closed under replacement of tautological equivalents (rte-versions). We give semantics for these logics, formulated by means of Kripke style models of the form , where w is a «distinguished» world, A is a set of worlds which are alternatives to w, and V is a valuation which for formulae and worlds assigns the truth-vales such that: (...) (i) for all formulae and all worlds, V preserves classical conditions for truth-value operators; (ii) for the world w and any formula ϕ, V(⬜ϕ,w) = 1 iff ∀x∈A V(ϕ,x) = 1; (iii) for other worlds formula ⬜ϕ has an arbitrary value. Moreover, for rte-versions of considered logics we must add the following condition: (iv) V(⬜χ,w) = V(⬜χ[ϕ/ψ],w), if ϕ and ψ are tautological equivalent. Finally, for C1, D1and E1 we must add queer models of the form in which: (i) holds and (ii') V(⬜ϕ,w) = 0, for any formula ϕ. We prove that considered logics are determined by some classes of above models. (shrink)

We show that the consistency of the theories “ holds below ” + “there is an injection ” + “both and fail” and + “ holds below ” + “there is an injection ” + “ satisfies the tree property” follow from the appropriate supercompactness hypotheses. These provide answers in a choiceless context to certain long‐standing open questions concerning, weak square, approachability, and the tree property. There is nothing special about, and the injection into can be from any ordinal (...) λ (which means that pcf theory can fail badly in the models constructed if ). (shrink)

We propose an approach for texture segmentation based on weak supervised learning. The weak supervision implies that the user marks only a single small patch for each class in the input image. These patches are used for training. We employ the method of graph cuts for the segmentation task. Our work demonstrates that even under such weak training, texture segmentation can be achieved efficiently and with good accuracy via graph cuts. Moreover, our approach uses a (...) simpler feature representation than that in similar contemporary segmentation approaches. We also provide a brief discussion indicating the good performance of our approach. We validate our method on various standard texture mosaics and also on segmentation of natural images with large texture variations. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Problems with a Weakly Pluralist Approach to Democratic EducationSheron Fraser-BurgessIntroductionPluralism embodies wide acknowledgement of various forms of difference. Appeals to pluralism involve arguments for the proliferating of differences as a social and moral ideal. Rather than being a formal political regime such as with democracy or social liberalism, in the extant political philosophy literature, pluralism brings considerations of diversity and equality to bear in philosophical analysis of traditional (...) systems of government.As a critique, pluralism falls along a continuum, which can be conceived of as iterations of the standing of particular ways of life, with respect to constraints of both equality and justice. At one end of the spectrum, all conceptions of the human good share a prima facie equality that belie overarching moral norms as a criterion of ranking. Questions about the incumbency of individual liberty motivate movement toward the opposing end, as allowing for the most just society warrants giving precedence to such values. The source of pluralism’s critical role is its inherent demand of a cogent resolution of the moral and, at times, political tension between equality and freedom.This article considers two forms of pluralism that lie near opposing extremes of the continuum and their implication for education. According to Horace Kallen’s and John Gray’s strong pluralism, the claim to the fact of differing values, cultures, etc., has primacy. As a corollary, maintaining the integrity of the social groups as holders of those values becomes central. In conflict with liberal democratic principles, however, protecting group values may occur at the expense of individual detractors within the group or may pose a threat of harm to others outside of the group who do not share these values.On the other hand, one form of weak pluralism, Amy Gutmann’s deliberative democracy, constrains pluralism on political grounds of individual [End Page 1] freedom. Deliberative democracy subsumes the holding of all values, including those shared with a social group, to the requirements of democracy. Both theories are considered as attempts to reconcile principles of treating everyone equally with not unjustly limiting individual freedom in a democracy. I raise principled and practical issues from education that call into question whether each theory satisfactorily resolves the conflicting demands of both equality and liberty. A third alternative is proposed as a salient consideration for democratic education. I begin with the pluralism of Horace Kallen and its relationship to that of John Gray.Strong PluralismHorace Kallen’s Cultural PluralismIn this section, I discuss Horace Kallen’s seminal account of cultural pluralism from the early twentieth century, classifying it with the strong value pluralism articulated by John Gray. Gray’s and Kallen’s pluralism have in common both the sanctioning of the fullest expression of difference and difficulties with making sense of the intuitive pull toward a criterion for the ranking of values that democracy dictates. I then consider the educational implications of Kallen’s view, particularly with respect to its actual influence upon multi-cultural initiatives of the 1970s and 1980s.Kallen coined the term “cultural pluralism” in the early twentieth century (Kallen 73). At this time, America was experiencing a great deal of social upheaval because of the huge influx of European and Asian immigrants. Movements such as nativism and Americanization fueled xenophobic sentiment. In this milieu, the full acculturation of new immigrants became a priority. In education, schooling policies penalized immigrant expressions of cultural identity, such as speaking one’s native language and practicing cultural traditions (Kallen 4).Kallen was one of the voices advocating not only that new immigrants should be allowed to maintain their cultural identity but also that a formal political solution be initiated which accommodated the predilection to do so. Nathan Glazer explains that there was at that time a general blindness to the possibility that “these groups or elements within them would not want to acculturate and assimilate but would want to preserve their corporate characters and distinctiveness even if prejudice and discrimination disappeared.” According to Glazer, such was the doctrine of assimilation for the first forty years of the twentieth century (7). [End Page 2]Kallen’s pluralism is a departure from the prevailing view in... (shrink)

We investigate sequent calculi for the weak modal (propositional) system reduced to the equivalence rule and extensions of it up to the full Kripke system containing monotonicity, conjunction and necessitation rules. The calculi have cut elimination and we concentrate on the inversion of rules to give in each case an effective procedure which for every sequent either furnishes a proof or a finite countermodel of it. Applications to the cardinality of countermodels, the inversion of rules and the derivability (...) of Löb rules are given. (shrink)

The purpose of this paper is twofold. First we want to extent a specific paranormal modal logic in such a way as obtain a paraconsistent and paracomplete multimodal logic able to formalize the notions of plausibility and certainty. With this logic at hand, and this is our second purpose, we shall use a modified version of Reiter‘s default logic to build a sort of inductive logic of plausibility and certainty able to represent some basic principles of epistemic inductive reasoning, (...) such as a negative autoepistemic principle, an `error-prone feature of induction' principle and a confirmation by enumeration principle. (shrink)

I defend a contextualist account of bare epistemic modal claims against recent objections. I argue that in uttering a sentence of the form ‘It might be that p,’ a speaker is performing two speech acts. First, she is (directly) asserting that in view of the knowledge possessed by some relevant group, it might be that p. The content of this first speech act is accounted for by the contextualist view. But the speaker's utterance also generates an indirect speech act (...) that consists in a weak suggestive that p. Since this second speech act is typically the main point of a bare epistemic modal utterance, our (negative or positive) responses to the utterance actually target this second speech act. I show how this two-speech-act account can explain the data recently adduced against contextualism. (shrink)

Many languages allow for “fake” uses of their past tense marker: the marker: can occur in certain contexts without conveying temporal pastness. Instead it appears to bear a modal meaning. Iatridou :231–270, 2000) has dubbed this phenomenon Fake Tense. Fake Tense is particularly common to conditional constructions. This paper analyzes Fake Tense in English conditional sentences as a certain kind of ambiguity: the past tense morphology can mark the presence of a temporal operator, but it can also signal a (...) specific modal operator. The ambiguity is proposed to be the result of recategorization: the Simple Past develops a second, modal meaning because of structural similarities between the temporal and the modal/epistemic domain. The proposal is spelled out in the generative semantics framework, using the restrictor approach to conditionals Semantics from different points of view, 1979; in: A. von Stechow and D. Wunderlich Semantics: an international handbook of contemporary research, 1991), and building on von Stechows et al.’s recent work on the English tense system The expression of time in language, 2010; Romero and von Stechow, Tense: introduction, 2008). (shrink)

Despite any shortcomings of Kant's transcendental philosophy, the spirit of Kant's approach is correct. In particular, Kant is correct to believe an accurate account of the types of “access” humans possess to internal and empirical content should form the groundwork for epistemic and ethical investigation and epistemic and ethical investigations cannot successfully circumvent this groundwork. In this context, the term “access” concerns the mental processes that render internal and external experience possible. In supporting the above claims, this article outlines (...) and defends what can be considered a weak version of Kant's transcendental approach. This weaker approach does not require the achievement of synthetic a priori judgments, which permit deductive conclusions concerning possible experience. (shrink)

Recent metaphysics has seen a surge of interest in grounding—a relation of non-causal determination underlying a distinctive kind of explanation common in philosophy. In this article, I investigate the connection between grounding and another phenomenon of great interest to metaphysics: ontological dependence. There are interesting parallels between the two phenomena: for example, both are commonly invoked through the use of “dependence” terminology, and there is a great deal of overlap in the motivations typically appealed to when introducing them. I (...) class='Hi'>approach the question of the relationship between grounding and ontological dependence through an investigation of their modal connections. I argue, firstly, that on the common assumption that grounding is factive, it can be shown that no known variety of rigid ontological dependence is either necessary or sufficient for grounding. I also offer some suggestions in support of the claim that this generalizes to every possible form of rigid ontological dependence. I then broaden the discussion by considering a non-factive conception of grounding, as well as by looking at forms of generic ontological dependence. I argue that there is at least one form of rigid ontological dependence that is sufficient for non-factive grounding, and that a form of generic dependence may be necessary both for factive and non-factive grounding. However, justifying even these fairly weak modal connections between grounding and ontological dependence turns out to require some quite specific and substantive assumptions about the two phenomena that have only rarely been discussed. (shrink)

Restrictivists hold that visual experience only represents low-level properties such as shape, spatial location, motion, color, etc. Expansionists contend that visual experience also represents high-level properties such as being a pine tree. I outline a new approach to support expansionism called the conflict cross-modal argument. What I call the conflict cross-modal effects occur when at least two perceptual systems disagree about some property belonging to a common stimulus, and this disagreement causes a change in the representational and (...) phenomenal content of the perceptual experience associated with one, or both, modalities. The conflict cross-modal argument works by accepting that if a property figures in a conflict cross-modal effect, then prima facie that property is a strong common sensible between the two modalities, and vision and another modality disagree about a property that is high-level for vision. After outlining this argument, and showing how it overcomes two obstacles that face traditional methods employed to defend expansionism, I turn to the well known Mcgurk effect as a case where vision and audition disagree about phoneme properties in order to employ my argument for the conclusion that phoneme properties are represented in visual experience. The upshot is that since phoneme properties are high-level for vision, we have an argument supporting expansionism. (shrink)

(1996). Knowledge elicitation using a multi‐modal approach. World Futures: Vol. 47, Unity and Diversity in Contemporary Systems Tinking: Systematic Pictures at an Exhibition, pp. 93-101.

Weakly Aggregative Modal Logic (WAML) is a collection of disguised polyadic modal logics with n-ary modalities whose arguments are all the same. WAML has some interesting applications on epistemic logic and logic of games, so we study some basic model theoretical aspects of WAML in this paper. Specifically, we give a van Benthem-Rosen characterization theorem of WAML based on an intuitive notion of bisimulation and show that each basic WAML system Kn lacks Craig Interpolation.

This paper proposes a novel relational view of autonomy designed to overcome the inadequacies of procedural and substantive views of autonomy as they relate to physician-assisted suicide requests for individuals with diminished cognitive functioning. Traditional and other relational views of autonomy regard a patient as an “isolated monad,” ignore patients with limited personal autonomy, and overlook the contexts in which decisions like PAS are made. However, these weaknesses become the strengths of a synthesized relational view of autonomy, which enhances the (...) personal autonomy of those with limited personal autonomy so that their PAS requests can be granted. (shrink)

This article proposes the adoption of a multi-modal system for allocating vaccine doses during large transnational outbreaks of infectious diseases. The chosen allocative criteria (public health need; country-income level; qualification through funding; and, subsidiarily, a modified lottery system) are adapted from a current embodiment of allocative multi-modality outside the context of public health: the New York City Marathon.

We present a general approach to quantified modal logics that can simulate most other approaches. The language is based on operators indexed by terms which allow to express de re modalities and to control the interaction of modalities with the first-order machinery and with non-rigid designators. The semantics is based on a primitive counterpart relation holding between n-tuples of objects inhabiting possible worlds. This allows an object to be represented by one, many, or no object in an accessible (...) world. Moreover by taking as primitive a relation between n-tuples we avoid some shortcoming of standard individual counterparts. Finally, we use cut-free labelled sequent calculi to give a proof-theoretic characterisation of the quantified extensions of each first-order definable propositional modal logic. In this way we show how to complete many axiomatically incomplete quantified modal logics. (shrink)

We present epistemic multilateral logic, a general logical framework for reasoning involving epistemic modality. Standard bilateral systems use propositional formulae marked with signs for assertion and rejection. Epistemic multilateral logic extends standard bilateral systems with a sign for the speech act of weak assertion (Incurvati and Schlöder 2019) and an operator for epistemic modality. We prove that epistemic multilateral logic is sound and complete with respect to the modal logic S5 modulo an appropriate translation. The logical framework developed (...) provides the basis for a novel, proof-theoretic approach to the study of epistemic modality. To demonstrate the fruitfulness of the approach, we show how the framework allows us to reconcile classical logic with the contradictoriness of so-called Yalcin sentences and to distinguish between various inference patterns on the basis of the epistemic properties they preserve. (shrink)

John Horty has proposed an approach to reasoning with ought-propositions which stands in contrast to the standard modal approach to deontic logic. Horty’s approach is based on default theories as known from the framework of Default Logic. It is argued that the approach cannot be extended beyond the most simple kinds of default theories and that it fails in particular to account for conditional obligations. The most plausible ways of straightening out the defects of the (...) approach conform to a simple theory of default reasoning in standard deontic language. (shrink)

Kolodny and MacFarlane have made a pioneering contribution to our understanding of how the interpretation of deontic modals can be sensitive to evidence and information. But integrating the discussion of information-sensitivity into the standard Kratzerian framework for modals suggests ways of capturing the relevant data without treating deontic modals as “informational modals” in their sense. I show that though one such way of capturing the data within the standard semantics fails, an alternative does not. Nevertheless I argue that we have (...) good reasons to adopt an information-sensitive semantics of the general type Kolodny and MacFarlane describe. Contrary to the standard semantics, relative deontic value between possibilities sometimes depends on which possibilities are live. I develop an ordering semantics for deontic modals that captures this point and addresses various complications introduced by integrating the discussion of information-sensitivity into the standard semantic framework. By attending to these complexities, we can also illuminate various roles that information and evidence play in logical arguments, discourse, and deliberation. (shrink)

We defend the view of epistemic `must' as weak and claim that `must p' is used when the speaker does not know p. Novel arguments for this well-known account are provided. The theory is extended to epistemic future.

Two views of game theory are discussed: (1) game theory as a description of the behavior of rational individuals who recognize each other’s rationality and reasoning abilities, and (2) game theory as an internally consistent recommendation to individuals on how to act in interactive situations. It is shown that the same mathematical tool, namely modal logic, can be used to explicitly model both views.

In this paper we investigate Boolean connexive logics in a language with modal operators: □, ◊. In such logics, negation, conjunction, and disjunction behave in a classical, Boolean way. Only implication is non-classical. We construct these logics by mixing relating semantics with possible worlds. This way, we obtain connexive counterparts of basic normal modal logics. However, most of their traditional axioms formulated in terms of modalities and implication do not hold anymore without additional constraints, since our implication is (...) weaker than the material one. In the final section, we present a tableau approach to the discussed modal logics. (shrink)

In his program of analytic pragmatism, Robert Brandom has presented a thoroughgoing reinterpretation of the place of analytic philosophy in the history of philosophy by linking his own non-representational ‘inferentialist’ approach to semantics to the rationalist – idealist tradition, and in particular, to Hegel. Brandom, however, has not been without his critics in regard to both his approach to semantics and his interpretation of Hegel. Here I single out four interlinked problematic areas facing Brandom's inferentialist semantics – his (...) approach of perceptual content, to de re attitudes, to perceptual experience and to modality, and then go on to contrast the different approach to these issues that is found in Hegel. While Hegel can helpfully be understood as anticipating an inferentialist semantics as Brandom claims, his is a weak inferentialism in contrast to Brandom's strong version. With his weakly inferentialist approach Hegel can, I suggest, be seen as providing a solution to the tangle of problems.. (shrink)

How does vagueness interact with metaphysical modality and with restrictions of it, such as nomological modality? In particular, how do definiteness, necessity (understood as restricted in some way or not), and actuality interact? This paper proposes a model-theoretic framework for investigating the logic and semantics of that interaction. The framework is put forward in an ecumenical spirit: it is intended to be applicable to all theories of vagueness that express vagueness using a definiteness (or: determinacy) operator. We will show how (...) epistemicists, supervaluationists, and theorists of metaphysical vagueness like Barnes and Williams (2010) can interpret the framework.  We will also present a complete axiomatization of the logic we recommend to both epistemicists and local supervaluationists. . (shrink)

Humans communicate with different modalities. We offer an account of multi-modal meaning coordination, taking speech-gesture meaning coordination as a prototypical case. We argue that temporal synchrony (plus prosody) does not determine how to coordinate speech meaning and gesture meaning. Challenging cases are asynchrony and broadcasting cases, which are illustrated with empirical data. We propose that a process algebra account satisfies the desiderata. It models gesture and speech as independent but concurrent processes that can communicate flexibly with each other and (...) exchange the same information more than once. The account utilizes the ψ-calculus, allowing for agents, input-output-channels, concurrent processes, and data transport of typed λ-terms. A multi-modal meaning is produced integrating speech meaning and gesture meaning into one semantic package. Two cases of meaning coordination are handled in some detail: the asynchrony between gesture and speech, and the broadcasting of gesture meaning across several dialogue contributions. This account can be generalized to other cases of multi-modal meaning. (shrink)