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)

According to the semantic view, a theory is characterized by a class of models. In this paper, we examine critically some of the assumptions that underlie this approach. First, we recall that models are models of something. Thus we cannot leave completely aside the axiomatization of the theories under consideration, nor can we ignore the metamathematics used to elaborate these models, for changes in the metamathematics often impose restrictions on the resulting models. Second, based on a parallel between van Fraassen’s (...) modal interpretation of quantum mechanics and Skolem’s relativism regarding set-theoretic concepts, we introduce a distinction between relative and absolute concepts in the context of the models of a scientific theory. And we discuss the significance of that distinction. Finally, by focusing on contemporary particle physics, we raise the question: since there is no general accepted unification of the parts of the standard model (namely, QED and QCD), we have no theory, in the usual sense of the term. This poses a difficulty: if there is no theory, how can we speak of its models? What are the latter models of? We conclude by noting that it is unclear that the semantic view can be applied to contemporary physical theories. (shrink)

Bas van Fraassen advocates a “Copenhagen variant” of the modal interpretation of quantum mechanics. However, he believes that the Copenhagen approach to measurement is not fully satisfactory, since it seems to rule out the possibility of providing a physical account of the observation process. This was also what John Wheeler had in mind when, in the mid-1950’s, he sponsored the “relative state” formulation proposed by his student Hugh Everett. Wheeler, who considered himself an orthodox Bohrian, tried to convince Bohr (...) to accept the improvement of the Copenhagen approach represented in his eyes by Everett’s proposal. This attempt gave rise to a lively debate, which has been only recently documented, and which provides an interesting framework for the appraisal of van Fraassen’s own programme. (shrink)

O autor analisa a validade de uma certa variante do “argumento ontológico" deAnselmo, a saber, a versão lógico-modal de Charles Hartshorne. Ele investiga, primeiramente, a origem dos argumentos de Hartshorne, partindo de uma interpretação de Anselmo; em segundo lugar, o argumento lógico-modal é apresentado, junto com as suas pressuposições e implicações. Finalmente, o autor propõe uma avaliação da abordagem de Hartshorne.

No tratado intitulado Segundos Analíticos, Aristóteles desenvolve uma teoria da demonstração científica e da ciência demonstrativa. Ali, o conhecimento científico é descrito pelo filósofo como envolvendo uma certa "necessidade". Alguns intérpretes associam esta noção de necessidade à necessidade modal, pertinente à silogística modal de Aristóteles. Esta interpretação, todavia, tornaria o modelo de ciência proposto nos Analíticos incompatível com os explananda das ciências da natureza, cuja cientificidade o próprio Aristóteles reiteradamente defendeu. A fim de evitar este inconveniente, abordamos (...) e reconstruímos a mencionada interpretação, reconhecemos suas falhas e propomos, seguindo outra tendência da literatura secundária, uma leitura alternativa da noção de necessidade como adequação explanatória, a qual garantiria a cientificidade dos fenômenos naturais. (shrink)

la82 12.00 Normal 0 21 false false false PT-BR X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabela normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-fareast-language:EN-US;} Este artigo mostra que o princípio primário da ciência do ente enquanto ente, apresentado e defendido por Aristóteles no Livro IV da Metafísica , é constituído pela bi-implicaçáo necessária (modal) entre os princípios de náo-contradiçáo e do terceiro (...) excluído, e náo somente, como na interpretaçáo tradicional, pelo primeiro destes princípios. Tal é mostrado através de uma interpretaçáo de uma parte do capítulo 3 e, em especial, de três partes do capítulo 4 deste escrito, onde Aristóteles desenvolve o que chamou "demonstraçáo refutativa", que consiste na demonstraçáo indireta do princípio primário por meio da refutaçáo da tese que nega (de modo forte) este mesmo princípio. A interpretaçáo apresentada no artigo mostra que neste procedimento lógico Aristóteles está defendendo tanto o princípio de náo-contradiçáo quanto o princípio do terceiro excluído, assumindo ambos como formulações equivalentes do princípio primário da ciência do ser enquanto ser.  . (shrink)

Apresento e desenvolvo neste artigo o problema da prova sortuda, analisando duas soluções para ele presentes na literatura. A primeira delas consistira em alegar que mostrar que o predicado está contido no sujeito não basta como demonstração da verdade de uma proposição, sendo preciso que se prove ainda que a noção relativa ao sujeito é logicamente consistente. A segunda repousaria em uma hierarquização modal, por assim dizer, dos pre- dicados integrantes de uma noção individual. Após exibir as razões que (...) me levam a rejeitar essas duas soluções, apresento os traços fundamentais de uma interpretação que me parece resolver o problema de maneira satisfatória. Minha posição envolve conceder ao Princípio da Razão Suficiente um papel central na compreensão do que significa, para Leibniz, provar que um determinado predicado está contido na noção relativa a um certo indivíduo. (shrink)

la82 12.00 Normal 0 21 false false false PT-BR X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabela normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-fareast-language:EN-US;} Este artigo mostra que o princípio primário da ciência do ente enquanto ente, apresentado e defendido por Aristóteles no Livro IV da Metafísica , é constituído pela bi-implicaçáo necessária (modal) entre os princípios de náo-contradiçáo e do terceiro (...) excluído, e náo somente, como na interpretaçáo tradicional, pelo primeiro destes princípios. Tal é mostrado através de uma interpretaçáo de uma parte do capítulo 3 e, em especial, de três partes do capítulo 4 deste escrito, onde Aristóteles desenvolve o que chamou "demonstraçáo refutativa", que consiste na demonstraçáo indireta do princípio primário por meio da refutaçáo da tese que nega (de modo forte) este mesmo princípio. A interpretaçáo apresentada no artigo mostra que neste procedimento lógico Aristóteles está defendendo tanto o princípio de náo-contradiçáo quanto o princípio do terceiro excluído, assumindo ambos como formulações equivalentes do princípio primário da ciência do ser enquanto ser.  . (shrink)

RESUMO No Curso de Inverno de 1928/29, Heidegger afirmou que a matematização irrestrita no conhecimento dos seres vivos resultaria numa falha no propósito de elaborar a ontologia da vida orgânica. No presente artigo, examino as razões que justificam essa concepção. Com base em interpretações das investigações de biólogos como Hans Driesch J. v. Uexküll e Hans Spemann, o argumento de Heidegger integra quatro passos: 1) uma abordagem mereológica do corpo orgânico, concebido como uma unidade funcional de aptidões e intrinsecamente relacionado (...) a um ambiente; 2) uma análise formal da constituição dinâmica das aptidões, cuja estrutura pulsional consiste no atravessamento regulatório de uma dimensão; 3) uma interpretação do princípio de unificação das aptidões em termos da aptidão para comportar-se com algo em um ambiente. Esta argumentação leva a duas conclusões gerais: a matematização irrestrita implica uma descrição mecânica que supõe a desconsideração da determinação modal dos organismos; a estrutura dimensional, regulatória e protointencional das aptidões orgânicas é o fator limitante da matematização da vida. ABSTRACT In the Winter Course of 1928/29, Heidegger declared that an unrestricted mathematical determination in the knowledge of living beings would imply a failure in the purpose of developing the ontology for organic life. In this paper, I examine the reasons that justify this idea. Based on interpretations of biological researches carried by Hans Driesch, J. v. Uexküll and Hans Spemann, Heidegger’s argument has three steps 1) a mereological account of the organic body, which is conceived both as a functional unity of capabilities and as intrinsically related to an environment; 2) a formal analysis of the dynamic constitution of capabilities, which instinctually driven structure is a regulatory traversing of a dimension; 3) an interpretation of the unification principle of capabilities, which is conceived as a capability of behaving towards something within an environment. This argument entails two general conclusions: first, the unrestricted mathematical determination implies a mechanical description that presupposes the neglect of the modal structure of organisms; second, the dimensional, regulatory and proto-intentional structure of the organic capabilities is the limiting factor of the mathematical determination of living organisms. (shrink)

RESUMO No Curso de Inverno de 1928/29, Heidegger afirmou que a matematização irrestrita no conhecimento dos seres vivos resultaria numa falha no propósito de elaborar a ontologia da vida orgânica. No presente artigo, examino as razões que justificam essa concepção. Com base em interpretações das investigações de biólogos como Hans Driesch J. v. Uexküll e Hans Spemann, o argumento de Heidegger integra quatro passos: 1) uma abordagem mereológica do corpo orgânico, concebido como uma unidade funcional de aptidões e intrinsecamente relacionado (...) a um ambiente; 2) uma análise formal da constituição dinâmica das aptidões, cuja estrutura pulsional consiste no atravessamento regulatório de uma dimensão; 3) uma interpretação do princípio de unificação das aptidões em termos da aptidão para comportar-se com algo em um ambiente. Esta argumentação leva a duas conclusões gerais: a matematização irrestrita implica uma descrição mecânica que supõe a desconsideração da determinação modal dos organismos; a estrutura dimensional, regulatória e protointencional das aptidões orgânicas é o fator limitante da matematização da vida.ABSTRACT In the Winter Course of 1928/29, Heidegger declared that an unrestricted mathematical determination in the knowledge of living beings would imply a failure in the purpose of developing the ontology for organic life. In this paper, I examine the reasons that justify this idea. Based on interpretations of biological researches carried by Hans Driesch, J. v. Uexküll and Hans Spemann, Heidegger’s argument has three steps 1) a mereological account of the organic body, which is conceived both as a functional unity of capabilities and as intrinsically related to an environment; 2) a formal analysis of the dynamic constitution of capabilities, which instinctually driven structure is a regulatory traversing of a dimension; 3) an interpretation of the unification principle of capabilities, which is conceived as a capability of behaving towards something within an environment. This argument entails two general conclusions: first, the unrestricted mathematical determination implies a mechanical description that presupposes the neglect of the modal structure of organisms; second, the dimensional, regulatory and proto-intentional structure of the organic capabilities is the limiting factor of the mathematical determination of living organisms. (shrink)

Um argumento recorrente contra a liberalização do aborto parte do pressuposto de que, desde o momento da fertilização, seres humanos são indivíduos (no sentido de serem algo que necessariamente ocorre em uma entidade apenas). Nesse artigo, argumento que esse não é um caso a partir da possibilidade de geminação monozigótica e do fato de identidades serem necessárias. Defendo as premissas do argumento e discuto as possíveis interpretações de sua conclusão. Argumento que a interpretação completa da conclusão desse argumento está (...) em concordância com a conclusão de um argumento semelhante, que parte de noção de organismo. -/- ENGLISH: A common pro-life argument assumes that humans are individuals (in the sense that they necessarily occur in one entity only) from the moment of fertilization. In this paper, argue that this is not the case because of the possibility of monozygotic twinning and the necessity of identities. I will defend the premises of the argument and discuss the possible interpretations of its conclusion. I argue that the correct interpretation of the conclusion of this argument is in agreement with the conclusion of a similar arguments from the notion of organism. (shrink)

O trabalho trata da experiência do autor em estudos de aspectos da relação estabelecida entre Georg Wilhelm Friedrich Hegel e Karl Heinrich Marx, notadamente aqueles de caráter metodológico. O texto passa também em revista uma produção europeia recente, principalmente italiana, que reivindica competentemente um estudo genético da referida temática. Nosso texto tem portanto a intenção de expor para o leitor brasileiro dimensões da interpretação internacional diretamente relacionada com as citadas teorias desenvolvidas por Hegel e Marx. Parte significativa do argumento (...) final do trabalho está preocupada com a demonstração do conteúdo cognitivo da teoria de Hegel, retomada por Marx, que corrobora elementos de uma lógica modal, fortemente apoiada naquilo que Hegel denomina determinações-da-reflexão, um importante mergulho feito pela Filosofia na investigação científica acerca da coesão interna de objetos apreendidos pela capacidade humana de abstração, onde coexistem orientações vinculadas ao espelhamento mental de entes exteriores à consciência, sempre ressignificados a partir das modalidades singularidade, particularidade e universalidade. Essa absorção metódica distingue objetividades produzidas pela atividade humana da realidade exterior natural. (shrink)

The Philosophy Course must develop in the student a technical ability for the interpretation of different discursive modalities - analogue to the "suspended atention", in the psychoanalytical sense - which will provide the student with the experience of "intelectual mastering", of ownership, however provisional, of a "language of safety", which holds in "suspension" the "places of conversation". By breaking the barrier between genres of discourses, between different subjects and between the various interlocutors, the course of philosophy - whether it is (...) taught in the university or in high school or even outside the regular courses - may, in this way, stimulate the production of an intense, laicized dialogue among multiple subjects of enunciaton, contributing for the constitution of the "public space". Only in this way can philosophy definitely conquer its maturity among us.O curso de filosofia deve desenvolver no aluno uma habilidade técnica na interpretação de diferentes modalidades discursivas - análoga ao "exercício de escuta", no sentido psicanalítico - que lhe permita a experiência da "dominação intelectual": da posse, ainda que provisória, de uma "língua da segurança" que coloque em "suspensão" os "lugares de conversação". Quebrando a barreira entre os gêneros dos discursos, entre as diferentes disciplinas, e entre os diversos interlocutores, o curso de filosofia - seja na universidade, no ensino médio e mesmo fora dos cursos regulares - poderá, desse modo, estimular a produção de um diálogo intenso, laicizado, entre múltiplos sujeitos de enunciação, contribuindo para a constituição do "espaço público". Somente assim a filosofia conquistará definitivamente entre nós, sua madureza. (shrink)

Apresento e desenvolvo neste artigo o problema da prova sortuda, analisando duas soluções para ele presentes na literatura. A primeira delas consistira em alegar que mostrar que o predicado está contido no sujeito não basta como demonstração da verdade de uma proposição, sendo preciso que se prove ainda que a noção relativa ao sujeito é logicamente consistente. A segunda repousaria em uma hierarquização modal, por assim dizer, dos pre- dicados integrantes de uma noção individual. Após exibir as razões que (...) me levam a rejeitar essas duas soluções, apresento os traços fundamentais de uma interpretação que me parece resolver o problema de maneira satisfatória. Minha posição envolve conceder ao Princípio da Razão Suficiente um papel central na compreensão do que significa, para Leibniz, provar que um determinado predicado está contido na noção relativa a um certo indivíduo. (shrink)

Timothy Williamson gives an original and provocative treatment of deep metaphysical questions about existence, contingency, and change, using the latest resources of quantified modal logic. Contrary to the widespread assumption that logic and metaphysics are disjoint, he argues that modal logic provides a structural core for metaphysics.

Modal ontolojik argüman, Tanrı’nın varlığını sadece bilfiil gerçek olan bu dünyada değil, bütün mümkün dünyalarda göstermeye yönelik bir argümandır. Anselm’in (1033-1109) Proslogion adlı eserinin 3. bölümünde “kendisinden daha büyüğü düşünülemeyen” şeklinde tanımlanan; Tanrı’nın var olmamasının da düşünülemeyeceğini, bu yüzden de varolmamasının imkansızlığı üzerinde kurulu yeni bir argüman bulunduğunu öne süren bazı araştırmacılar, bu argümanı mümkün dünyalar semantiği yardımıyla formüle edip, “modal ontolojik argüman” şeklinde adlandırmışlardır. Çok farklı şekillerde formüle edilmiş bu argüman kabaca Tanrı’nın mümkünse zorunlu olması, dolayısıyla bilfiil (...) gerçek olan bu dünyada da var olması gerektiğini savunur. (shrink)

A textbook on modal logic, intended for readers already acquainted with the elements of formal logic, containing nearly 500 exercises. Brian F. Chellas provides a systematic introduction to the principal ideas and results in contemporary treatments of modality, including theorems on completeness and decidability. Illustrative chapters focus on deontic logic and conditionality. Modality is a rapidly expanding branch of logic, and familiarity with the subject is now regarded as a necessary part of every philosopher's technical equipment. Chellas here offers (...) an up-to-date and reliable guide essential for the student. (shrink)

Epistemic modal operators give rise to something very like, but also very unlike, Moore's paradox. I set out the puzzling phenomena, explain why a standard relational semantics for these operators cannot handle them, and recommend an alternative semantics. A pragmatics appropriate to the semantics is developed and interactions between the semantics, the pragmatics, and the definition of consequence are investigated. The semantics is then extended to probability operators. Some problems and prospects for probabilistic representations of content and context are (...) explored. (shrink)

Dispositionality is a modal notion of a certain sort. When an object is said to have a disposition, we typically understand this to mean that under certain circumstances, the object would behave in a certain way. For instance, a fragile object is disposed to break when dropped onto a concrete surface. It need not actually break - its being fragile has implications that, so to speak, point beyond the actual world. According to dispositionalism, all modal features of the (...) world may be accounted for in terms of its dispositional features. My aim in this paper is to assess the prospects for dispositionalism by examining the most promising theories. Sections 1 and 2 clarify the assumptions and desiderata of a successful dispositionalist theory of modality. Section 3 introduces the principles governing the dispositionalist theories that apparently meet the desiderata. Sections 4 through 6 show that dispositionalism nonetheless faces three problems: while dispositions help account for modal features of the world that are local, diachronic, or gradable, they cannot account for certain modal features of the world that are global, synchronic, or absolute. I end by discussing the costs of preserving dispositionalism. (shrink)

I critically examine the claim that modal collapse arguments against the traditional doctrine of divine simplicity (DDS) are in general fallacious. In a recent paper, Christopher Tomaszewski alleges that modal collapse arguments against DDS are invalid, owing to illicit substitutions of nonrigid singular terms into intensional contexts. I show that this is not, in general, the case. I show, further, that where existing modal collapse arguments are vulnerable to this charge the arguments can be repaired without any (...) apparent dialectical impropriety. I conclude that the genuine debate over modal collapse and divine simplicity and modal collapse is substantially a controversy over the metaphysics of divine action, and that this constitutes a fruitful direction in which to take future discussions of the subject. (shrink)

This modern, advanced textbook reviews modal logic, a field which caught the attention of computer scientists in the late 1970's.

Proof Theory of Modal Logic is devoted to a thorough study of proof systems for modal logics, that is, logics of necessity, possibility, knowledge, belief, time, computations etc. It contains many new technical results and presentations of novel proof procedures. The volume is of immense importance for the interdisciplinary fields of logic, knowledge representation, and automated deduction.

There is a lot that we don't know. That means that there are a lot of possibilities that are, epistemically speaking, open. For instance, we don't know whether it rained in Seattle yesterday. So, for us at least, there is an epistemic possibility where it rained in Seattle yesterday, and one where it did not. What are these epistemic possibilities? They do not match up with metaphysical possibilities - there are various cases where something is epistemically possible but not metaphysically (...) possible, and vice versa. How do we understand the semantics of statements of epistemic modality? The ten new essays in this volume explore various answers to these questions, including those offered by contextualism, relativism, and expressivism. (shrink)

Boris Kment takes a new approach to the study of modality that emphasises the origin of modal notions in everyday thought. He argues that the concepts of necessity and possibility originate in counterfactual reasoning, which allows us to investigate explanatory connections. Contrary to accepted views, explanation is more fundamental than modality.

In the middle of the last century, it was common to explain the notion of necessity in linguistic terms. A necessary truth, it was said, is a sentence whose truth is guaranteed by linguistic rules. Quine famously argued that, on this view, de re modal claims do not make sense. “Porcupettes are porcupines” is necessarily true, but it would be a mistake to say of a particular porcupette that it is necessarily a porcupine, or that it is possibly purple. (...) Linguistic theories of necessity fell out of favour with the publication of Kripke’s Naming and Necessity, and Quine’s arguments were put aside. In her recent book, Norms and Necessity, Amie Thomasson presents her modal normativism, which is an updated version of the mid-century theories just described. Quine’s arguments are thus relevant once again. We recapitulate Quine’s central argument, in the context of modal normativism. We then criticise Amie Thomasson’s discussion of de re modality. We finish by briefly presenting an alternative account of de re modal statements, which is compatible with modal normativism. (shrink)

Most Probably: Epistemic Modality in Old Babylonian by Nathan Wasserman is the first attempt to provide a description of the domain of epistemic modality in Old Babylonian Akkadian. This attempt is not entirely successful, for several reasons. Methodological inconsistency often impairs the author’s ability to convince the reader of his solutions. Both primary data and existing secondary literature are used only selectively, which renders the proposed description problematic. Finally, the lack of cross-referencing between the chapters evokes the feeling that the (...) different particles do not quite constitute a system. (shrink)

For a novice this book is a mathematically-oriented introduction to modal logic, the discipline within mathematical logic studying mathematical models of reasoning which involve various kinds of modal operators. It starts with very fundamental concepts and gradually proceeds to the front line of current research, introducing in full details the modern semantic and algebraic apparatus and covering practically all classical results in the field. It contains both numerous exercises and open problems, and presupposes only minimal knowledge in mathematics. (...) A specialist can use the book as a source of references. Results and methods of many directions in propositional modal logic, from completeness and duality to algorithmic problems, are collected and systematically presented in one volume. (shrink)

This paper explains and defends the idea that metaphysical necessity is the strongest kind of objective necessity. Plausible closure conditions on the family of objective modalities are shown to entail that the logic of metaphysical necessity is S5. Evidence is provided that some objective modalities are studied in the natural sciences. In particular, the modal assumptions implicit in physical applications of dynamical systems theory are made explicit by using such systems to define models of a modal temporal logic. (...) Those assumptions arguably include some necessitist principles. -/- Too often, philosophers have discussed ‘metaphysical’ modality — possibility, contingency, necessity — in isolation. Yet metaphysical modality is just a special case of a broad range of modalities, which we may call ‘objective’ by contrast with epistemic and doxastic modalities, and indeed deontic and teleological ones (compare the distinction between objective probabilities and epistemic or subjective probabilities). Thus metaphysical possibility, physical possibility and immediate practical possibility are all types of objective possibility. We should study the metaphysics and epistemology of metaphysical modality as part of a broader study of the metaphysics and epistemology of the objective modalities, on pain of radical misunderstanding. Since objective modalities are in general open to, and receive, natural scientific investigation, we should not treat the metaphysics and epistemology of metaphysical modality in isolation from the metaphysics and epistemology of the natural sciences. -/- In what follows, Section 1 gives a preliminary sketch of metaphysical modality and its place in the general category of objective modality. Section 2 reviews some familiar forms of scepticism about metaphysical modality in that light. Later sections explore a few of the many ways in which natural science deals with questions of objective modality, including questions of quantified modal logic. (shrink)

A very simple contextualist treatment of a sentence containing an epistemic modal, e.g. a might be F, is that it is true iff for all the contextually salient community knows, a is F. It is widely agreed that the simple theory will not work in some cases, but the counterexamples produced so far seem amenable to a more complicated contextualist theory. We argue, however, that no contextualist theory can capture the evaluations speakers naturally make of sentences containing epistemic modals. (...) If we want to respect these evaluations, our best option is a relativist theory of epistemic modals. On a relativist theory, an utterance of a might be F can be true relative to one context of evaluation and false relative to another. We argue that such a theory does better than any rival approach at capturing all the behaviour of epistemic modals. (shrink)

What does 'might' mean? One hypothesis is that 'It might be raining' is essentially an avowal of ignorance like 'For all I know, it's raining'. But it turns out these two constructions embed in different ways, in particular as parts of larger constructions like Wittgenstein's 'It might be raining and it's not' and Moore's 'It's raining and I don't know it', respectively. A variety of approaches have been developed to account for those differences. All approaches agree that both Moore sentences (...) and Wittgenstein sentences are classically consistent. In this paper I argue against this consensus. I adduce a variety of new data which I argue can best be accounted for if we treat Wittgenstein sentences as being classically inconsistent. This creates a puzzle, since there is decisive reason to think that 'Might p' is classically consistent with 'Not p'. How can it also be that 'Might p and not p' and 'Not p and might p' are classically inconsistent? To make sense of this situation, I propose a new theory of epistemic modals and their interaction with embedding operators. This account makes sense of the subtle embedding behavior of epistemic modals, shedding new light on their meaning and, more broadly, the dynamics of information in natural language. -/- . (shrink)

According to the modal view, essence admits of reductive analysis in exclusively modal terms. Fine (1994) argues that modal view delivers an inadequate analysis of essence. This paper defends the modal view from Fine's challenge. This defense proceeds by examining the disagreement between Finean primitivists and Quinean eliminativists about essence. In order to model this disagreement, a distinction between essence and a separable concept, nature, is required. This distinction is then used to show that Fine's challenge (...) is misdirected and therefore unsuccessful. (shrink)

This book is collection of the the author’s previously published papers on the philosophy of modality and tense and it also includes three unpublished papers. The author provides an exposition and defence of certain positions for which he is well-known: the intelligibility of modality de re; the primitiveness of the modal; and the primacy of the actual over the possible. He also argues for some less familiar positions: the existence of distinctive forms of natural and normative necessity, not reducible (...) to any form of metaphysical necessity; the need to make a distinction between the worldly and unworldly, analogous to the distinction between the tensed and the tenseless; and the viability of a nonstandard form of realism about tense, which recognizes the tensed character of reality without conceding there is any privileged standpoint from which it is to be viewed. (shrink)

We argue that genuine modal realism can be extended, rather than modified, so as to allow for the possibility of nothing concrete, a possibility we term ‘metaphysical nihilism’. The issue should be important to the genuine modal realist because, not only is metaphysical nihilism itself intuitively plausible, but also it is supported by an argument with pre-theoretically credible premises, namely, the subtraction argument. Given the soundness of the subtraction argument, we show that there are two ways that the (...) genuine modal realist can accommodate metaphysical nihilism: (i) by allowing for worlds containing only spatiotemporal points and (ii) by allowing for a world containing nothing but the null individual. On methodological grounds, we argue that the genuine modal realist should reject the former way but embrace the latter way. (shrink)

The present monograph is a slightly revised version of my Habilitations schrift Proof-theoretic Aspects of Intensional and Non-Classical Logics, successfully defended at Leipzig University, November 1997. It collects work on proof systems for modal and constructive logics I have done over the last few years. The main concern is display logic, a certain refinement of Gentzen's sequent calculus developed by Nuel D. Belnap. This book is far from offering a comprehensive presentation of generalized sequent systems for modal logics (...) broadly conceived. The proof-theory of non-classical logics is a rapidly developing field, and even the generalizations of the ordinary notion of sequent listed in Chapter 1 can hardly be presented in great detail within a single volume. In addition to further investigating the various approaches toward generalized Gentzen systems, it is important to compare them and to discuss their relative advantages and disadvantages. An initial attempt at bringing together work on different kinds of proof systems for modal logics has been made in [188]. Another step in the same direction is [196]. Since Chapter 1 contains introductory considerations and, moreover, every remaining chapter begins with some surveying or summarizing remarks, in this preface I shall only emphasize a relation to philosophy that is important to me, register the sources of papers that have entered this book in some form or another, and acknowledge advice and support. (shrink)

This essay proposes a new theory of agentive modals: ability modals and their duals, compulsion modals. After criticizing existing approaches—the existential quantificational analysis, the universal quantificational analysis, and the conditional analysis—it presents a new account that builds on both the existential and conditional analyses. On this account, the act conditional analysis, a sentence like ‘John can swim across the river’ says that there is some practically available action that is such that if John tries to do it, he swims across (...) the river. The essay argues that the act conditional analysis avoids the problems faced by existing accounts of agentive modality and shows how the act conditional analysis can be extended to an account of generic agentive modal claims. The upshot is a new vantage point on the role of agentive modal ascriptions in practical discourse: ability ascriptions serve as a kind of hypothetical guarantee, and compulsion ascriptions as a kind of nonhypothetical guarantee. (shrink)