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.

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)

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)

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)

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)

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)

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)

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)

In this paper, I will argue that there is a version of possibilism—inspired by the modal analogue of Kit Fine’s fragmentalism—that can be combined with a weakening of actualism. The reasons for analysing this view, which I call Modal Fragmentalism, are twofold. Firstly, it can enrich our understanding of the actualism/possibilism divide, by showing that, at least in principle, the adoption of possibilia does not correspond to an outright rejection of the actualist intuitions. Secondly, and more specifically, it (...) can enrich our understanding of concretism, by proving that, at least in principle, the idea that objects have properties in an absolute manner is compatible with transworld identity. (shrink)

Timothy Williamson has argued that in the debate on modal ontology, the familiar distinction between actualism and possibilism should be replaced by a distinction between positions he calls contingentism and necessitism. He has also argued in favor of necessitism, using results on quantified modal logic with plurally interpreted second-order quantifiers showing that necessitists can draw distinctions contingentists cannot draw. Some of these results are similar to well-known results on the relative expressivity of quantified modal logics with so-called (...) inner and outer quantifiers. The present paper deals with these issues in the context of quantified modal logics with generalized quantifiers. Its main aim is to establish two results for such a logic: Firstly, contingentists can draw the distinctions necessitists can draw if and only if the logic with inner quantifiers is at least as expressive as the logic with outer quantifiers, and necessitists can draw the distinctions contingentists can draw if and only if the logic with outer quantifiers is at least as expressive as the logic with inner quantifiers. Secondly, the former two items are the case if and only if all of the generalized quantifiers are first-order definable, and the latter two items are the case if and only if first-order logic with these generalized quantifiers relativizes. (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)

This paper examines "moderate modal skepticism", a form of skepticism about metaphysical modality defended by Peter van Inwagen in order to blunt the force of certain modal arguments in the philosophy of religion. Van Inwagen’s argument for moderate modal skepticism assumes Yablo's (1993) influential world-based epistemology of possibility. We raise two problems for this epistemology of possibility, which undermine van Inwagen's argument. We then consider how one might motivate moderate modal skepticism by relying on a different (...) epistemology of possibility, which does not face these problems: Williamson’s (2007: ch. 5) counterfactual-based epistemology. Two ways of motivating moderate modal skepticism within that framework are found unpromising. Nevertheless, we also find a way of vindicating an epistemological thesis that, while weaker than moderate modal skepticism, is strong enough to support the methodological moral van Inwagen wishes to draw. (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.

It is widely agreed that the intelligibility of modal metaphysics has been vindicated. Quine's arguments to the contrary supposedly confused analyticity with metaphysical necessity, and rigid with non-rigid designators.2 But even if modal metaphysics is intelligible, it could be misconceived. It could be that metaphysical necessity is not absolute necessity – the strictest real notion of necessity – and that no proposition of traditional metaphysical interest is necessary in every real sense. If there were nothing otherwise “uniquely metaphysically (...) significant” about metaphysical necessity, then paradigmatic metaphysical necessities would be necessary in one sense of “necessary”, not necessary in another, and that would be it. The question of whether they were necessary simpliciter would be like the question of whether the Parallel Postulate is true simpliciter – understood as a pure mathematical conjecture, rather than as a hypothesis about physical spacetime. In a sense, the latter question has no objective answer. In this article, I argue that paradigmatic questions of modal metaphysics are like the Parallel Postulate question. I then discuss the deflationary ramifications of this argument. I conclude with an alternative conception of the space of possibility. According to this conception, there is no objective boundary between possibility and impossibility. Along the way, I sketch an analogy between modal metaphysics and set theory. (shrink)

This paper motivates and develops a novel semantic framework for deontic modals. The framework is designed to shed light on two things: the relationship between deontic modals and substantive theories of practical rationality and the interaction of deontic modals with conditionals, epistemic modals and probability operators. I argue that, in order to model inferential connections between deontic modals and probability operators, we need more structure than is provided by classical intensional theories. In particular, we need probabilistic structure that interacts directly (...) with the compositional semantics of deontic modals. However, I reject theories that provide this probabilistic structure by claiming that the semantics of deontic modals is linked to the Bayesian notion of expectation. I offer a probabilistic premise semantics that explains all the data that create trouble for the rival theories. (shrink)

The paper begins with a clarification of the notions of intuition (and, in particular, modal intuition), modal error, conceivability, metaphysical possibility, and epistemic possibility. It is argued that two-dimensionalism is the wrong framework for modal epistemology and that a certain nonreductionist approach to the theory of concepts and propositions is required instead. Finally, there is an examination of moderate rationalism’s impact on modal arguments in the philosophy of mind -- for example, Yablo’s disembodiment argument and Chalmers’s (...) zombie argument. A less vulnerable style of modal argument is defended, which nevertheless wins the same anti-materialist conclusions sought by these other arguments. (shrink)

Neste artigo apresentamos de forma breve uma teoria searliana de interpretação dos atos de fala. Mostramos através do exemplo das metáforas que, conforme proposta por Searle, a interpretação de atos de fala consistiria em reconhecer a intenção do falante. Esse processo se daria por meio do uso de regras convencionais da linguagem tanto pelo falante quanto pelo ouvinte. Contudo, as metáforas são um exemplo de que essa proposta de interpretação não é suficiente para descrever o processo pelo (...) qual os agentes interpretam atos de fala. Argumentamos que se deve acrescentar a esse processo a noção de regras estratégicas. Seguindo Peirce, duas regras estratégicas são oferecidas: o princípio da coerência e o princípio da economia. Parece também satisfatório acrescentar o princípio da não-contradição. Embora estudos empíricos não sejam definitivos sobre o tema da interpretação, em especial sobre metáforas, os resultados apontam para a aplicação de regras estratégicas na interpretação. Finalmente, é sugerido que se Searle está certo ao dizer que interpretação é o reconhecimento da intenção do falante, então a interpretação depende do uso de regras convencionais e do uso de regras estratégicas. (shrink)

The paper argues against Peacocke's moderate rationalism in modality. In the first part, I show, by identifying an argumentative gap in its epistemology, that Peacocke's account has not met the Integration Challenge. I then argue that we should modify the account's metaphysics of modal concepts in order to avoid implausible consequences with regards to their possession conditions. This modification generates no extra explanatory gap. Yet, once the minimal modification that avoids those implausible consequences is made, the resulting account cannot (...) support Peacocke's moderate rationalism. (shrink)

The paper compares the suitability of two different epistemologies of counterfactuals—(EC) and (W)—to elucidate modal knowledge. I argue that, while both of them explain the data on our knowledge of counterfactuals, only (W)—Williamson’s epistemology—is compatible with all counterpossibles being true. This is something on which Williamson’s counterfactual-based account of modal knowledge relies. A first problem is, therefore, that, in the absence of further, disambiguating data, Williamson’s choice of (W) is objectionably biased. A second, deeper problem is that (W) (...) cannot satisfactorily elucidate modal knowledge. Third, from a naturalistic perspective, the nature of this second problem favours (EC) against (W). (shrink)

Lange argues that some natural phenomena can be explained by appeal to mathematical, rather than natural, facts. In these “distinctively mathematical” explanations, the core explanatory facts are either modally stronger than facts about ordinary causal law or understood to be constitutive of the physical task or arrangement at issue. Craver and Povich argue that Lange’s account of DME fails to exclude certain “reversals”. Lange has replied that his account can avoid these directionality charges. Specifically, Lange argues that in legitimate DMEs, (...) but not in their “reversals,” the empirical fact appealed to in the explanation is “understood to be constitutive of the physical task or arrangement at issue” in the explanandum. I argue that Lange’s reply is unsatisfactory because it leaves the crucial notion of being “understood to be constitutive of the physical task or arrangement” obscure in ways that fail to block “reversals” except by an apparent ad hoc stipulation or by abandoning the reliance on understanding and instead accepting a strong realism about essence. (shrink)

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

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)

Provisional draft, pre-production copy of my book “The Modal Future” (forthcoming with Cambridge University Press).

Abstract Timothy Williamson has recently proposed to undermine modal skepticism by appealing to the reducibility of modal to counterfactual logic ( Reducibility ). Central to Williamson’s strategy is the claim that use of the same non-deductive mode of inference ( counterfactual development , or CD ) whereby we typically arrive at knowledge of counterfactuals suffices for arriving at knowledge of metaphysical necessity via Reducibility. Granting Reducibility, I ask whether the use of CD plays any essential role in a (...) Reducibility-based reply to two kinds of modal skepticism. I argue that its use is entirely dispensable, and that Reducibility makes available replies to modal skeptics which show certain propositions to be metaphysically necessary by deductive arguments from premises the modal skeptic accepts can be known. Content Type Journal Article Pages 1-19 DOI 10.1007/s11098-011-9784-4 Authors Juhani Yli-Vakkuri, Wolfson College, Oxford University, Oxford, OX2 6UD UK Journal Philosophical Studies Online ISSN 1573-0883 Print ISSN 0031-8116. (shrink)

In a recent article forthcoming in *Mind*, Leech (2020) presents a challenge for essentialist accounts of metaphysical modality: why should it be that essences imply corresponding necessities? Leech’s main focus is to argue that one cannot overcome the challenge by utilizing an account of essence in terms of generalized identity due to Correia and Skiles (2019), on pain of circularity. In this reply, we will show how to use identity-based essentialism to bridge ‘epistemic’ and ‘explanatory’ understandings of this alleged essence-to-necessity (...) gap without circularity, Leech’s arguments notwithstanding. We do so by first presenting a novel proof that generalized identities imply corresponding necessities. We then propose several substantive identity-based explanations of how it is, exactly, that essences imply necessities. -/- . (shrink)

The practice of scientific modelling often resorts to hypothetical, false, idealised, targetless, partial, generalised, and other types of modelling that appear to have at least partially non-actual targets. In this paper, I will argue that we can avoid a commitment to non-actual targets by sketching a framework where models are understood as having networks of possibilities as their targets. This raises a further question: what are the truthmakers for the modal claims that we can derive from models? I propose (...) that we can find truthmakers for the modal claims derived from models in actuality, even in the case of supposedly non-actual targets. I then put this framework to use by examining a case study concerning the modelling of superheavy elements. (shrink)

This article presents an overview of the basic philosophical motivations for, and some recent work in, modal set theory.

According to the simple modal account of essence, an object has a property essentially just in case it has it in every world in which it exists. As many have observed, the simple modal account is implausible for a number of reasons. This has led to various proposals for strengthening the account, for example, by adding a restriction to the intrinsic or sparse properties. I argue, however, that these amendments to the simple modal account themselves fail. Drawing (...) on lessons from these failures, I propose a new version of a modal account, inspired by Ruth Barcan Marcus's defense of the coherence of quantified modal logic, according to which an object has a property essentially just in case (i) it has it in every world in which it exists, (ii) the property is discriminating (or non-trivial), and (iii) the property is qualitative. The resulting account of essence does not face any of the standard objections other accounts face, and I defend it from other potential objections. (shrink)

We discuss the semantic significance of a puzzle concerning ‘ought’ and conditionals recently discussed by Kolodny and MacFarlane. We argue that the puzzle is problematic for the standard Kratzer-style analysis of modality. In Kratzer’s semantics, modals are evaluated relative to a pair of conversational backgrounds. We show that there is no sensible way of assigning values to these conversational backgrounds so as to derive all of the intuitions in Kolodny and MacFarlane’s case. We show that the appropriate verdicts can be (...) derived by extending Kratzer’s framework to feature a third conversational background and claiming that the relevant reading of ‘ought’ is sensitive to this parameter. (shrink)

This volume contains eighteen papers, three with new postscripts, that were written over the past 35 years. Five of the papers have not been previously published. Together they provide a comprehensive account of modal reality—the realm of possible worlds—from a Humean perspective, with excursions into neighboring topics in metaphysics. Part 1 sketches an account of reality as a whole, both the mathematical and the modal, defending a form of plenitudinous realism: every consistent proposition is true of some portion (...) of reality. Part 2 presents and defends a realist theory of concrete possible worlds with an absolute ontological distinction between the actual and the merely possible. Part 3 presents and defends a Humean account of modal plenitude, formulating and endorsing principles of recombination, of plenitude of possible structures, and of plenitude of alien contents. Part 4 applies the Humean account to truthmaking, mereology, spacetime, and quantities. I argue that holding fast to Humean strictures leads to views that differ in radical ways from those put forth by contemporary metaphysicians. (shrink)