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)

Individual objects have potentials: paper has the potential to burn, an acorn has the potential to turn into a tree, some people have the potential to run a mile in less than four minutes. Barbara Vetter provides a systematic investigation into the metaphysics of such potentials, and an account of metaphysical modality based on them. -/- In contemporary philosophy, potentials have been recognized mostly in the form of so-called dispositions: solubility, fragility, and so on. Vetter takes dispositions as her (...) starting point, but argues for and develops a more comprehensive conception of potentiality. She shows how, with this more comprehensive conception, an account of metaphysical modality can be given that meets three crucial requirements: Extensional correctness: providing the right truth-values for statements of possibility and necessity; formal adequacy: providing the right logic for metaphysical modality; and semantic utility: providing a semantics that links ordinary modal language to the metaphysics of modality. -/- The resulting view of modality is a version of dispositionalism about modality: it takes modality to be a matter of the dispositions of individual objects. This approach has a long philosophical tradition going back to Aristotle, but has been largely neglected in contemporary philosophy. In recent years, it has become a live option again due to the rise of anti-Humean, powers-based metaphysics. The aim of Potentiality is to develop the dispositionalist view in a way that takes account of contemporary developments in metaphysics, logic, and semantics. (shrink)

Some metaphysicians believe that metaphysical modality is explainable by the essences of objects. In §II, I spell out the definitional view of essence, and in §III, a working notion of metaphysical explanation. Then, in §IV, I consider and reject five natural ways to explain necessity by essence: in terms of the principle that essential properties can't change, in terms of the supposed obviousness of the necessity of essential truth, in terms of the logical necessity of definitions, in terms of (...) Fine's logic of essence, and in terms of the theory of real definitions. I will conclude that the present evidence favours rejecting the hypothesis that modality is explainable by essence. (shrink)

There are three theories in the epistemology of modality that have received sustained attention over the past 20 years: conceivability-theory, counterfactual-theory, and deduction-theory. In this paper we argue that all three face what we call the problem of modal epistemic friction. One consequence of the problem is that for any of the three accounts to yield modal knowledge, the account must provide an epistemology of essence. We discuss an attempt to fend off the problem within the context of the (...) internalism versus externalism debate about epistemic justification. We then investigate the effects that the PMEF has on reductive and non-reductive theories of the relation between essence and modality. (shrink)

It is my aim in this paper to show that the contemporary assimilation of essence to modality is fundamentally misguided and that, as a consequence, the corresponding conception of metaphysics should be given up. It is not my view that the modal account fails to capture anything which might reasonably be called a concept of essence. My point, rather, is that the notion of essence which is of central importance to the metaphysics of identity is not to be understood (...) in modal terms or even to be regarded as extensionally equivalent to a modal notion. The one notion is, if I am right, a highly refined version of the other; it is like a sieve which performs a similar function but with a much finer mesh. (shrink)

This book addresses two related questions that have first arisen in Toulmin’s seminal book on the uses of argument. The first question is the one of the relationship between the semantic analysis of modality and the structure of arguments. The second question is the one of the distinctive place, or role, of modality in the fundamental structure of arguments. These two questions concern how modality, as a semantic category, relates to the fundamental structure of arguments. The book (...) addresses modality and argumentation also according to another perspective by looking at how different linguistic modal expressions may be taken as argumentative indicators. It explores the role of modal expressions as argumentative indicators by using the Italian modal system as a case study. At the same time, it uses predictions/forecasts in the business-financial daily press to investigate the relation between modality and the context of argumentation. (shrink)

This article surveys recent developments in the epistemology of modality.

The John Locke Lectures for 1955-6, delivered at the University of Oxford.

This book develops an argument for a foundational theory of modality using higher-order logic. The use of higher-order logic in metaphysics is motivated, and a particular higher-order logic is introduced. Fine-grained theories of propositional individuation are shown to be problematic, and a course-grained theory of propositional individuation is defended. On the basis of this theory, it is argued that the metaphysical necessities can be delineated using purely logical terms; by adding an actuality operator, it is shown that the logic (...) of metaphysical necessity is S5. The theoretical role of possible worlds is articulated, and shown to be satisfied by maximal propositions if it satisfied by anything; the existence of such maximal propositions is demonstrated using plural propositional quantification. The resulting theory reduces metaphysical modal terms to higher-order logical terms, and thereby vindicates a widespread modal conception of metaphysics. (shrink)

The epistemology of modality has focused on metaphysical modality and, more recently, counterfactual conditionals. Knowledge of kinds of modality that are not metaphysical has so far gone largely unexplored. Yet other theoretically interesting kinds of modality, such as nomic, practical, and ‘easy’ possibility, are no less puzzling epistemologically. Could Clinton easily have won the 2016 presidential election—was it an easy possibility? Given that she didn’t in fact win the election, how, if at all, can we know (...) whether she easily could have? This paper investigates the epistemology of the broad category of ‘objective’ modality, of which metaphysical modality is a special, limiting case. It argues that the same cognitive mechanisms that are capable of producing knowledge of metaphysical modality are also capable of producing knowledge of all other objective modalities. This conclusion can be used to explain the roles of counterfactual reasoning and the imagination in the epistemology of objective modality. (shrink)

The Diodorean interpretation of modality reads the operator as it is now and always will be the case that. In this paper time is modelled by the four-dimensional Minkowskian geometry that forms the basis of Einstein's special theory of relativity, with event y coming after event x just in case a signal can be sent from x to y at a speed at most that of the speed of light (so that y is in the causal future of x).It (...) is shown that the modal sentences valid in this structure are precisely the theorems of the well-known logic S4.2, and that this system axiomatises the logics of two and three dimensional spacetimes as well. (shrink)

Analytic philosophy has recently demonstrated a revived interest in metaphysical problems about possibility and necessity. Graeme Forbes here provides a careful description of the logical background of recent work in this area for those who may be unfamiliar with it, moving on to d discuss the distinction between modality de re and modality de dicto and the ontological commitments of possible worlds semantics. In addition, Forbes offers a unified theory of the essential properties of sets, organisms, artefacts, substances, (...) and events, based on the doctrine that identity facts must be intrinsically grounded, and analyzes and rejects apparent counterexamples to this doctrine. (shrink)

Time and modality show remarkable similarities. Each of the most discussed theories in philosophy of time finds an analogous counterpart in modal metaphysics, suggesting that the parallel between the two notions is metaphysically deep. This chapter offers a brief overview of their analogies. Section 1 addresses the analogy between presentism and actualism. Section 2 explores the analogy between non-presentist theories and possibilism. Section 3 discusses the analogy between temporal and modal persistence.

This paper surveys recent "new actualist" approaches to modality that do without possible worlds and locate modality squarely in the actual world. New actualist theories include essentialism and dispositionalism about modality, each of which can come in different varieties. The commonalities and differences between these views, as well as their shared motivations, are layed out.

There is an ongoing debate in the metaphysics of dispositions regarding which type of modality governs their manifestation. This paper assumes as its default position the view that dispositions manifest by conditional necessity; that is, when in appropriate circumstances dispositions manifest necessarily. From this standpoint, the paper engages critically with an existing alternative in the literature, put forward most prominently by Mumford and Anjum, and known as dispositional modality. According to this latter view, even when in appropriate manifestation (...) conditions, dispositions only merely tend towards their manifestation. By raising difficulties for this alternative, the paper offers indirect support for the conditional necessity view. (shrink)

A series of recent studies have explored the impact of people's judgments regarding physical law, morality, and probability. Surprisingly, such studies indicate that these three apparently unrelated types of judgments often have precisely the same impact. We argue that these findings provide evidence for a more general hypothesis about the kind of cognition people use to think about possibilities. Specifically, we suggest that this aspect of people's cognition is best understood using an idea developed within work in the formal semantics (...) tradition, namely the notion of modality. On the view we propose, people may have separate representations for physical, moral and probabilistic considerations, but they also integrate these various considerations into a unified representation of modality. (shrink)

MEANING POSTULATES REINSTATED If I am right in agreeing with Cresswell that the "logicarrlexicaT distinction is one of degree rather than one of kind, that in turn impugns the distinction between the official truth-rules that define logical ...

A striking feature of the contemporary philosophical scene is the flourishing of a number of research programs aimed in one way or another at making intentional soup out of nonintentional bones—more carefully, specifying in a resolutely nonintentional, nonsemantic vocabulary, sufficient conditions for states of an organism or other system to qualify as contentful representations. This is a movement with a number of players, but for my purposes here, the work of Dretske, Fodor, and Millikan can serve as paradigms. The enterprise (...) in which they are jointly engaged is not so much one of conceptual analysis as it has been traditionally understood as one of conceptual engineering. That is, instead of thinking about what ordinary people or even sophisticated philosophers already mean by terms such as ‘representation’, they appeal to the tools of the special sciences to describe abstractly, but in criticizable detail, how one might craft a situation in which some state arguably deserves to be characterized as ‘representationally contentful’ in various important senses. Insofar as the theories are good ones, they may shed light on how human knowers actually work. But their immediate aim is a broader one: to say what would count as doing the trick, rather than how we manage to do it. (shrink)

This chapter analyzes several key themes in Kant’s views about modality. We begin with the pre-critical Only Possible Argument in Support of a Demonstration of the Existence of God, in which Kant distinguishes between formal and material elements of possibility, claims that all possibility requires an actual ground, and argues for the existence of a single necessary being. We then briefly consider how Kant’s views change in his mature period, especially concerning the role of form and thought in defining (...) modality. Kant’s mature views, however, present two difficult interpretive puzzles. The first puzzle concerns whether Kant has a generally reductive view of modality. While Kant’s views on logical modality, the role of actuality in grounding possibility, and the relation of modality to cognition all suggest reduction, we argue that the categorial status of modal concepts and the difficulty in even identifying amodal grounds for modal facts all suggest a non-reductive view. The second puzzle concerns whether Kant accepts modal facts or properties at the noumenal level. While Kant’s appeal to noumenal necessary connections, the contingency of noumenal willing, and the idea of a necessary noumenal being suggest that he endorses noumenal modality, his claims that modal concepts express only relations to the faculty of cognition and his claim that modal concepts arise from our distinctive psychological structures, we argue, suggest that he rejects noumenal modality. We conclude by considering potential solutions to these puzzles. (shrink)

I develop a psychological account for how it is that we use imagination to metaphysically modalize, i.e., to reach conclusions about metaphysical modality. Specifically, I argue that Nichols and Stich’s (2003) cognitive theory of imagination can be extended to metaphysical modalizing. I then use the extension to explicate philosophical disagreements about whether a scenario is metaphysically possible. Thereafter, I address Nichols’ (2006) objection that psychologizing imagination makes it clear that imagination is unreliable when used to metaphysically modalize. The end (...) result is a naturalistic account for how imagination enables us to metaphysically modalize. (shrink)

This book concerns the foundations of epistemic modality and hyperintensionality and their applications to the philosophy of mathematics. David Elohim examines the nature of epistemic modality, when the modal operator is interpreted as concerning both apriority and conceivability, as well as states of knowledge and belief. The book demonstrates how epistemic modality and hyperintensionality relate to the computational theory of mind; metaphysical modality and hyperintensionality; the types of mathematical modality and hyperintensionality; to the epistemic status (...) of large cardinal axioms, undecidable propositions, and abstraction principles in the philosophy of mathematics; to the modal and hyperintensional profiles of the logic of rational intuition; and to the types of intention, when the latter is interpreted as a hyperintensional mental state. Chapter \textbf{2} argues for a novel type of expressivism based on the duality between the categories of coalgebras and algebras, and argues that the duality permits of the reconciliation between modal and hyperintensional cognitivism and modal and hyperintensional expressivism. Elohim develops a novel, topic-sensitive truthmaker semantics for dynamic epistemic logic, and develops a novel, dynamic two-dimensional semantics grounded in two-dimensional hyperintensional Turing machines. Chapter \textbf{3} provides an abstraction principle for two-dimensional (hyper-)intensions. Chapter \textbf{4} advances a topic-sensitive two-dimensional truthmaker semantics, and provides three novel interpretations of the framework along with the epistemic and metasemantic. Chapter \textbf{5} applies the fixed points of the modal $\mu$-calculus in order to account for the iteration of epistemic states in a single agent, by contrast to availing of modal axiom 4 (i.e. the KK principle). The fixed point operators in the modal $\mu$-calculus are rendered hyperintensional, which yields the first hyperintensional construal of the modal $\mu$-calculus in the literature and the first application of the calculus to the iteration of epistemic states in a single agent instead of the common knowledge of a group of agents. Chapter \textbf{6} advances a solution to the Julius Caesar problem based on Fine's `criterial' identity conditions which incorporate conditions on essentiality and grounding. Chapter \textbf{7} provides a ground-theoretic regimentation of the proposals in the metaphysics of consciousness and examines its bearing on the two-dimensional conceivability argument against physicalism. The topic-sensitive epistemic two-dimensional truthmaker semantics developed in chapters \textbf{2} and \textbf{4} is availed of in order for epistemic states to be a guide to metaphysical states in the hyperintensional setting. -/- Chapters \textbf{8-12} provide cases demonstrating how the two-dimensional hyperintensions of hyperintensional, i.e. topic-sensitive epistemic two-dimensional truthmaker, semantics, solve the access problem in the epistemology of mathematics. Chapter \textbf{8} examines the interaction between Elohim's hyperintensional semantics and the axioms of epistemic set theory, large cardinal axioms, the Epistemic Church-Turing Thesis, the modal axioms governing the modal profile of $\Omega$-logic, Orey sentences such as the Generalized Continuum Hypothesis, and absolute decidability. These results yield inter alia the first hyperintensional Epistemic Church-Turing Thesis and hyperintensional epistemic set theories in the literature. Chapter \textbf{9} examines the modal and hyperintensional commitments of abstractionism, in particular necessitism, and epistemic hyperintensionality, epistemic utility theory, and the epistemology of abstraction. Elohim countenances a hyperintensional semantics for novel epistemic abstractionist modalities. Elohim suggests, too, that higher observational type theory can be applied to first-order abstraction principles in order to make first-order abstraction principles recursively enumerable, i.e. Turing machine computable, and that the truth of the first-order abstraction principle for two-dimensional hyperintensions is grounded in its being possibly recursively enumerable and the machine being physically implementable. Chapter \textbf{10} examines the philosophical significance of hyperintensional $\Omega$-logic in set theory and discusses the hyperintensionality of metamathematics. Chapter \textbf{11} provides a modal logic for rational intuition and provides a hyperintensional semantics. Chapter \textbf{12} avails of modal coalgebras to interpret the defining properties of indefinite extensibility, and avails of hyperintensional epistemic two-dimensional semantics in order to account for the interaction between interpretational and objective modalities and the truthmakers thereof. This yields the first hyperintensional category theory in the literature. Elohim invents a new mathematical trick in which first-order structures are treated as categories, and Vopenka's principle can be satisfied because of the elementary embeddings between the categories and generate Vopenka cardinals in the category of Set in category theory. Chapter \textbf{13} examines modal responses to the alethic paradoxes. Elohim provides a counter-example to epistemic closure for logical deduction. Chapter \textbf{14} examines, finally, the modal and hyperintensional semantics for the different types of intention and the relation of the latter to evidential decision theory. (shrink)

There is good reason to believe that scientific realism requires a commitment to the objective modal structure of the physical world. Causality, equilibrium, laws of nature, and probability all feature prominently in scientific theory and explanation, and each one is a modal notion. If we are committed to the content of our best scientific theories, we must accept the modal nature of the physical world. But what does the scientific realist’s commitment to physical modality require? We consider whether scientific (...) realism is compatible with Humeanism about the laws of nature, and we conclude that it is not. We specifically identify three major problems for the best-systems account of lawhood: its central concept of strength cannot be formulated non-circularly, it cannot offer a satisfactory account of the laws of the special sciences, and it can offer no explanation of the success of inductive inference. In addition, Humeanism fails to be naturalistically motivated. For these reasons, we conclude that the scientific realist must embrace natural necessity. (shrink)

Modality is standardly thought to come in two varieties: de dicto and de re. De re modality concerns the attribution of modal features to things or individuals, and enshrines a commitment to Aristotelian essentialism. This chapter considers how David Lewis's conception of de re modality fits into his overall metaphysics. The hypothesis is that the driving force behind his metaphysics in general, and his adherence to counterpart theory in particular, is the distinctly Humean thought that necessary connections (...) between distinct existences are literally unintelligible. Lewis's appeal to counterpart theory in his account of truthmakers is explicitly aimed at delivering a truthmaker principle that eschews necessary connections. Lewis's attitude towards several well‐rehearsed debates in contemporary ontology and the reasons underlying that attitude closely mirror Hume's incendiary verdict on "divinity and school metaphysics." Finally, de re modality is connected with his adherence to the doctrine of "Humean supervenience". (shrink)

This paper discusses the account of alethic modality as presented by Wilfrid Sellars in his earlier work from 1947 to 1958. Its aim is twofold. First, I discuss Sellars' analysis by exploring its historical relationship to Carnap's account of modality. I argue that Carnap's early syntactic treatment of modality profoundly influenced Sellars' own so-called ‘regulist' account of modality in terms of rules of inference. Furthermore, it is suggested that Sellars' lesser-known possible worlds analysis was influenced by (...) Carnap's later semantic account of modality. The second aim of the paper is a critical one. I raise a number of objections to Sellars’ account of modality and argue that his account confronts some serious limitations. I also argue that Sellars does not provide a satisfying explanation of the relationship between his regulist account and his possible worlds analysis. I offer such an explanation by arguing that his regulist account should be understood as a pragmatic account of what is conveyed by the use of modal sentences, whereas his possible worlds analysis is a semantic account of the asserted content of modal statements. That is, the regulist account and the possible worlds analysis have different explanatory targets. (shrink)

What kind of semantics should someone who accepts the epistemicist theory of vagueness defended in Timothy Williamson’s Vagueness (1994) give a definiteness operator? To impose some interesting constraints on acceptable answers to this question, I will assume that the object language also contains a metaphysical necessity operator and a metaphysical actuality operator. I will suggest that the answer is to be found by working within a three-dimensional model theory. I will provide sketches of two ways of extracting an epistemicist semantics (...) from that model theory, one of which I will find to be more plausible than the other. (shrink)

1. Reference and modality by W. V. O. Quine.--2. Modality and description by A. F. Smullyan.--3. Extensionality by R. B. Marcus.--4. Quantification into causal contexts by D. Føllesdal.--5. Semantical considerations on modal logic by S. A. Kripke.--6. Essentialism and quantified modal logic by T. Parsons.--7. Reference, essentialism, and modality by L. Linsky.--8. Quantifiers and propositional attitudes by W. V. O. Quine.--9. Quantifying in by D. Kaplan.--10. Semantics for propositional attitudes by J. Hintikka.--11. On Carnap's analysis of statements (...) of assertion and belief by A. Church.--Bibliography (p. [173]-175). (shrink)

This essay defends two theses regarding the explanation, or ground, of modality in the early modern period. First, for philosophers in the period, essences ground a range of important modal facts. Second, as the period progresses, we witness increased skepticism about certain modal facts, due to a growing skepticism about the scope or existence of essences. These theses are supported by examination of three case studies: Descartes’ treatment of substance and mode (which forms the core of his ontology); Malebranche’s (...) treatment of causation (which bears on his defense of occasionalism); and Locke’s treatment of necessary connections among properties (which is related to his accounts of individuals and kinds). It is shown that in each case, claims about necessity and possibility take center stage, and that in each case, the status of these claims hinges on the status of claims about essences. (shrink)

Inquiry into the metaphysics of essence tends to be pursued in a realist and model-theoretic spirit, in the sense that metaphysical vocabulary is used in a metalanguage to model truth conditions for the object-language use of essentialist vocabulary. This essay adapts recent developments in proof-theoretic semantics to provide a nominalist analysis for a variety of essentialist vocabularies. A metalanguage employing explanatory inferences is used to individuate introduction and elimination rules for atomic sentences. The object-language assertions of sentences concerning essences are (...) then interpreted as devices for marking off structural features of the explanatory inferences that, under a given interpretation, constitute the contents of the atoms of the language. On this proposal, object-language essentialist vocabulary is mentioned in a proof-theoretic metalanguage that uses a vocabulary of explanation. The result is a nominalist interpretation of essence as a modality, understood in the grammatical sense as a modification of the copula, and a view of metaphysical inquiry that is closely connected to the explanatory commitments present in first-order inquiry into things like sets, chemicals, and organisms. This result illustrates that some of the presuppositions that have animated analytic metaphysics over the last few decades can be profitably substituted with more practice-oriented conceptions of the forms of reasoning at work in different domains of human knowledge. (shrink)

Many draw the distinction between truth in, and truth at, a possible world. The latter notion purportedly allows for propositions to be true relative to worlds even if they do not exist relative to those same worlds. Despite its wide application, the distinction is controversial. Some think that the notion of truth at a world is unintelligible. Here, I outline and discuss the most influential argument for the unintelligibility of truth at a world, The Picture Thinking Argument. I outline and (...) defend a neglected strategy to respond to this, arguing that if we take seriously the idea that possible worlds represent total ways the world could be, the distinction can be drawn intelligibly. (shrink)

Section 1 introduces the category of objective modality, closely related to linguists’ category of circumstantial or dynamic modals, and explains metaphysical modality as its maximal element. Section 2 discusses various kinds of skepticism about modality, as in Hume and recent authors, and argues that it is illmotivated to apply such skepticism to metaphysical modality but not to more restricted objective modalities, including nomic modality. Section 3 suggests that the role of counterfactual conditionals in applications of (...) scientific theories involves an objective modal dimension. Section 4 briefly discusses the role of objective probabilities in scientific theories as exemplifying the scientific study of objective modality. Section 5 summarizes a case study of dynamical systems theory, widely used in natural science, as a mathematical theory whose intended applications are objectively modal, as perspicuously articulated in a language with modal and temporal operators and propositional quantification. State spaces in natural science characterize objective possibilities. Section 6 argues that, although those possibilities are usually more restricted than metaphysical possibility, their scientific study is a partial study of metaphysical possibility too. (shrink)

In his influential article ‘Essence and Modality’, Fine proposes a definition of necessity in terms of the primitive essentialist notion ‘true in virtue of the nature of’. Fine’s proposal is suggestive, but it admits of different interpretations, leaving it unsettled what the precise formulation of an Essentialist definition of necessity should be. In this paper, four different versions of the definition are discussed: a singular, a plural reading, and an existential variant of Fine’s original suggestion and an alternative version (...) proposed by Correia which is not based on Fine’s primitive essentialist notion. The first main point of the paper is that the singular reading is untenable. The second that given plausible background assumptions, the remaining three definitions are extensionally equivalent. The third is that, this equivalence notwithstanding, Essentialists should adopt Correia’s version of the definition, since both the existential variant, which has de facto been adopted as the standard version of the definition in the literature, and the plural reading suffer from problems connected to Fine’s primitive essentialist notion. (shrink)

Journal Name: Cognitive Linguistics Issue: Ahead of print.

Possible worlds, concrete or abstract as you like, are irrelevant to the truthmakers for modality—or so I shall argue in this paper. First, I present the neo-Humean picture of modality, and explain why those who accept it deny a common sense view of modality. Second, I present what I take to be the most pressing objection to the neo-Humean account, one that, I argue, applies equally well to any theory that grounds modality in possible worlds. Third, (...) I present an alternative, properties-based theory of modality and explore several specific ways to flesh the general proposal out, including my favored version, the powers theory. And, fourth, I offer a powers semantics for counterfactuals that each version of the properties-based theory of modality can accept, mutatis mutandis. Together with a definition of possibility and necessity in terms of counterfactuals, the powers semantics of counterfactuals generates a semantics for modality that appeals to causal powers and not possible worlds. (shrink)

It is widely held that for an action to be free it must be the case that the agent can do otherwise. Compatibilists and incompatibilists disagree over what this ability amounts to. Two recent articles offer novel perspectives on the debate by employing Angelika Kratzer’s semantics of ‘can’. Alex Grzankowski proposes that Kratzer’s semantics favour incompatibilism because they make valid a version of the Consequence Argument. Christian List argues that Kratzer’s semantics favour a novel form of compatibilism. I argue that (...) List’s compatibilist application of Kratzer’s semantics faces problems not faced by Grzankowski’s incompatibilist employment of them. On the other hand I argue that Kratzer’s semantics make Grzankowski’s version of the Consequence Argument valid only at the cost of rendering it dialectically useless. Contrary to both views Kratzer’s semantics do not appear to add substantial weight to either side of the compatibilism/incompatibilism dispute. (shrink)

This dissertation is about flexibility as a dimension of reality, an objective—independent of mind and language—phenomenon typically referred to as ‘metaphysical modality’. It develops a novel modal account of why reality could be different: that is, why claims like “Possibly, there are talking donkeys,” or “Humphrey could have won the election” are true or false. I contend that primitive dispositional properties called ‘powers’ explain such claims, and do so better than possible-world accounts of modality. The problem with possible-world (...) accounts is that they fail to capture what we mean by modal terms like ‘possibly’, ‘can’, or ‘necessarily’. The phenomenon they capture with possible worlds cannot adequately explain, for instance, that Humphrey regrets not winning the election because: he could have made a difference. Humphrey is told that he could have won the election because some entity represents him as such. But what does some entity’s representing Humphrey have to do with whether Humphrey could have won the election? Simply calling that entity a ‘possible world’ is no help. Powers do better in this regard, preserving a common-sense notion of modality where, because of what a power can do it acts as a cross-roads in history, marking places where reality could have unfolded differently. As such, powers are more clearly modally significant than possible worlds. The conclusion shows how to use powers to underwrite possible-world semantics without possible worlds. (shrink)

Standard philosophical accounts attempt to understand physical modality either in terms of special metaphysical entities and relationships or in terms of the organization of non-modal information, as in Best Systems Analysis. This paper defends an alternative to both these approaches in which invariance and various independence conditions play a central role. The methodological importance of separating law-claims from claims about initial and boundary conditions is highlighted.

In this second and last paper of the two part investigation on "Modality and Axiomatic Theories of Truth" we apply a general strategy for constructing modal theories over axiomatic theories of truth to the theory Kripke-Feferman. This general strategy was developed in the first part of our investigation. Applying the strategy to Kripke-Feferman leads to the theory Modal Kripke-Feferman which we discuss from the three perspectives that we had already considered in the first paper, where we discussed the theory (...) Modal Friedman-Sheard. That is, we first show that Modal Kripke-Feferman preserves theoremhood modulo translation with respect to modal operator logic. Second, we develop a modal semantics fitting the newly developed theory. Third, we investigate whether the modal predicate of Modal Kripke-Feferman can be understood along the lines of a proposal of Kripke, namely as a truth predicate modified by a modal operator. (shrink)

A study of various central and connected topics in philosophical logic and the theory of meaning. There are important sections on the relation between linguistic and abstract entities, on necessity and convention, on meaning, sense and reference, and on entailment. Dr Lewy proposes a number of original solutions to problems which have been widely discussed in literature, and there is in particular a sharp and sustained criticism of conventionalism and reductionism. These are among the most difficult and intricate issues in (...) contemporary philosophy, but Dr Lewy writes with great clarity and a minimum of technicality. Where his views are controversial they are explained and supported in a detail which makes it both possible and necessary for potential critics to state their disagreement precisely. The book should therefore be of value as an advanced textbook as well as an original contribution to philosophical logic. (shrink)

This essay considers Kant’s theory of modality in light of a debate in contemporary modal metaphysics and modal logic concerning the Barcan formulas. The comparison provides a new and fruitful perspective on Kant’s complex and sometimes confusing claims about possibility and necessity. Two central Kantian principles provide the starting point for the comparison: that the possible must be grounded in the actual and that existence is not a real predicate. Both are shown to be intimately connected to the Barcan (...) formulas, and Kant’s views on what he distinguishes as three different kinds of modality are then considered in light of this connection. (shrink)

Is what could have happened but never did as real as what did happen? What did happen, but isn't happening now, happened at another time. Analogously, one can say that what could have happened happens in another possible world. Whatever their views about the reality of such things as possible worlds, philosophers need to take this analogy seriously. Adriane Rini and Max Cresswell exhibit, in an easy step-by-step manner, the logical structure of temporal and modal discourse, and show that every (...) temporal construction has an exact parallel that requires a language that can refer to worlds, and vice versa. They make precise, in a way which can be articulated and tested, the claim that the parallel is at work behind even ordinary talk about time and modality. The book gives metaphysicians a sturdy framework for the investigation of time and modality - one that does not presuppose any particular metaphysical view. (shrink)