In this chapter, it is suggested that our epistemic access to metaphysical modality generally involves rationalist, a priori elements. However, these a priori elements are much more subtle than ‘traditional’ modal rationalism assumes. In fact, some might even question the ‘apriority’ of these elements, but I should stress that I consider a priori and a posteriori elements especially in our modal inquiry to be so deeply intertwined that it is not easy to tell them apart. Supposed metaphysically necessary identity statements (...) involving natural kind terms are a good example: the fact that empirical input is crucial in establishing their necessity has clouded the role and content of the a priori input, as I have previously argued. For instance, the supposed metaphysically necessary identity statement involving water and its microstructure can only be established with the help of a controversial a priori principle concerning the determination of chemical properties by microstructure. The Kripke-Putnam framework of modal epistemology fails precisely because it is unclear whether the required a priori element is present. My positive proposal builds on E. J. Lowe’s work. Lowe holds that our knowledge of metaphysical modality is based on our knowledge of essence. Lowe’s account strives to offer a uniform picture of modal epistemology: essence is the basis of all our modal knowledge. This is the basis of Lowe’s modal rationalism. I believe that Lowe’s proposal is on the right lines in the case of abstract objects, but I doubt that it can be successfully applied to the case of natural kinds. Accordingly, the case of natural kinds will be my main focus and I will suggest that modal rationalism, at least as it is traditionally understood, falls short of explaining modal knowledge concerning natural kinds. Yet, I think that Lowe has identified something of crucial importance for modal epistemology, namely the essentialist, a priori elements present in our modal inquiry. The upshot is that rather than moving all the way from modal rationalism to modal empiricism, a type of hybrid approach, ‘empirically-informed modal rationalism ’, can be developed. (shrink)

We shall use Gödel’s Second Incompleteness Theorem to show that consistency is not possibility, and then argue that the argument does serious damage to some theories of modality where consistency plays a major but not exclusive role.

This book deals with an internal theme of metaphysics, which is the metaphysics of the laws of nature. The author presents traditional contemporary theories, as well as his own original theory, and evaluates each one at a time. He also addresses the problem of the modality of the laws of nature and makes some criticism of the standard view of necessity as truth in all possible worlds, and shows an application of his discussion to the metaphysics of physics. / Este (...) livro trata de um tema interno à metafísica, que é a metafísica das leis da natureza. O autor apresenta as teorias tradicionais contemporâneas, tal como também a sua própria teoria original, e avalia cada uma delas por vez. Ele também aborda o problema da modalidade das leis da natureza e apresenta uma certa crítica à visão padrão da necessidade como verdade em todos os mundos possíveis, e mostra uma aplicação da sua discussão à metafísica da Física. (shrink)

We can distinguish two non-equivalent ways in which a natural language argument can be valid: it can be interpretationally or representationally valid. However, there is just one notion of classical first-order validity for formal languages: truth-preservation in all classical first-order models. To ease the tension, Baumgartner suggests that we should understand interpretational and representational validity as imposing different adequacy conditions on formalizations of natural language arguments. I argue against this proposal. To that end, I first show that Baumgartner’s definition of (...) representational validity is extensionally inadequate. I present a number of natural language arguments that we pre-theoretically hold to be representationally valid, but are not representationally valid according to Baumgartner’s definition. I then point to two further untenable features of Baumgartner’s definitions: according to Baumgartner’s definition of a representationally correct formalization, we cannot arrive at formalizations in a recursive way, and Baumgartner’s definition of representational validity is non-monotonic. I conclude that interpretational and representational validity cannot be understood as merely imposing different adequacy conditions on formalizations. If we want to capture our interpretational and representational intuitions, we need two different formal definitions of validity. (shrink)

It is a truth universally acknowledged that a claim of metaphysical modality, in possession of good alethic standing, must be in want of an essentialist foundation. Or at least so say the advocates of the reductive-essence-first view, according to which all modality is to be reductively defined in terms of essence. Here, I contest this bit of current wisdom. In particular, I offer two puzzles—one concerning the essences of non-compossible, complementary entities, and a second involving entities whose essences are modally (...) ‘loaded’—that together strongly call into question the possibility of reducing modality to essence. (shrink)

It is a truth universally acknowledged that a claim of metaphysical modality, in possession of good alethic standing, must be in want of an essentialist foundation. Or at least so say the advocates of thereductive-essence-firstview, according to which all modality is to be reductively defined in terms of essence. Here, I contest this bit of current wisdom. In particular, I offer two puzzles—one concerning the essences of non-compossible, complementary entities, and a second involving entities whose essences are modally ‘loaded’—that together (...) strongly call into question the possibility of reducing modality to essence. (shrink)

This paper first argues that we can bring out a tension between the following three popular doctrines: (i) the canonical reduction of metaphysical modality to essence, due to Fine, (ii) contingentism, which says that possibly something could have failed to be something, and (iii) the doctrine that metaphysical modality obeys the modal logic S5. After presenting two such arguments (one from the theorems of S4 and another from the theorems of B), I turn to exploring various conclusions we might draw (...) in light of these results, and argue that none comes cost free. In the course of laying out possible responses to my arguments, we'll have a chance to evaluate various doctrines about the interplay between contingency and essence, as well as develop some alternative reductions of metaphysical modality to essence. I don't decisively come down in favor of one response over the others, though I say some things that point towards the conclusion that essence has no role to play in reducing metaphysical modality. (shrink)

We characterize, more precisely than before, what Rawls calls the “analytical” method of drawing up a list of basic liberties. This method employs one or more general conditions that, under any just social order whatever, putative entitlements must meet for them to be among the basic liberties encompassed, within some just social order, by Rawls’s first principle of justice (i.e., the liberty principle). We argue that the general conditions that feature in Rawls’s own account of the analytical method, which employ (...) the notion of necessity, are too stringent. They ultimately fail to deliver as basic certain particular liberties that should be encompassed within any fully adequate scheme of liberties. To address this under-generation problem, we provide an amended general condition. This replaces Rawls’s necessity condition with a probabilistic condition and it appeals to the standard liberal prohibition on arbitrary coercion by the state. We defend our new approach both as apt to feature in applications of the analytical method and as adequately grounded in justice as fairness as Rawls articulates the theory’s fundamental ideas. (shrink)

A common view is that self-identity is essential to objects if anything is. Itself a substantive metaphysical view, this is a position of some import in wider debates, particularly in connection with such problems as physicalism and personal identity. In this article I challenge the view. I distinguish between two accounts of essence, the modal and the definitional, and argue that self-identity is essential to objects on the former but not on the latter. After laying out my case, I deal (...) with a number of objections. (shrink)

Husserl’s official account of essence is modal. It is also, I submit, incompatible with the role that essence is supposed to play, especially relative to necessity, in his overall philosophy. In the Husserlian framework, essence should rather be treated as a non-modal notion. The point, while not generally acknowledged, has been made before (by Kevin Mulligan for one); yet the arguments given for it, though perhaps sound, are not Husserlian. In this paper I present a thoroughly Husserlian argument for that (...) claim, as well as a Husserlian essentialist account of necessity. I also discuss the role of grounding within the account. (shrink)

One common objection to Conventionalism about modality is that since it is contingent what our conventions are, the modal facts themselves will thereby be contingent. A standard reply is that Conventionalists can accept this, if they reject the S4 axiom, that what is possibly possible is possible. I first argue that this reply is inadequate, but then continue to argue that it is not needed, because the Conventionalist need not concede that the contingency of our conventions has any bearing on (...) the modal status of necessary truths. It is explained why this does not compromise the Conventionalist claim that necessity – and particularly, essence – is due to conventions. (shrink)

I formulate and defend two sceptical theses on specific parts of our modal knowledge (unqualified and absolute modalities). My main point is that unqualified modal sentences are defective in that they fail to belong unambiguously to specific modal kinds and thus cannot be evaluated; hence, we must be sceptical of beliefs involving them.

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)

Given quasi-realism, the claim is that any attempt to naturalise modal epistemology would leave out absolute necessity. The reason, according to Simon Blackburn, is that we cannot offer an empirical psychological explanation for why we take any truth to be absolutely necessary, lest we lose any right to regard it as absolutely necessary. In this paper, I argue that not only can we offer such an explanation, but also that the explanation won’t come with a forfeiture of the involved necessity. (...) Using ‘squaring the circle’ as evidence, I show that, contrary to quasi-realism, absolute necessity won’t be left out in attempts to naturalise modal epistemology. (shrink)

Gideon Rosen has recently sketched an argument which aims to establish that the notion of metaphysical modality is systematically ambiguous. His argument contains a crucial sub-argument which has been used to argue for Metaphysical Contingentism, the view that some claims of fundamental metaphysics are metaphysically contingent rather than necessary. In this paper, Rosen’s argument is explicated in detail and it is argued that the most straight-forward reconstruction fails to support its intended conclusion. Two possible ways to save the argument are (...) rebutted and it is furthermore argued that the crucial sub-argument only supports a rather particular variant of Metaphysical Contingentism. (shrink)

I set up a dilemma, concerning metaphysical modality de re, for the essentialist opponent of a ‘two senses’ view of necessity. I focus specifically on Frank Jackson's two-dimensional account in his From Metaphysics to Ethics (Oxford: Oxford University Press, 1998). I set out the background to Jackson's conception of conceptual analysis and his rejection of a two senses view. I proceed to outline two purportedly objective (as opposed to epistemic) differences between metaphysical and logical necessity. I conclude that since one (...) of these differences must hold and since each requires the adoption of a two senses view of necessity, essentialism is not consistent with the rejection of a two senses view. (shrink)

This paper responds to criticism of the Kripkean account of logical truth in first-order modal logic. The criticism, largely ignored in the literature, claims that when the box and diamond are interpreted as the logical modality operators, the Kripkean account is extensionally incorrect because it fails to reflect the fact that all sentences stating truths about what is logically possible are themselves logically necessary. I defend the Kripkean account by arguing that some true sentences about logical possibility are not logically (...) necessary. (shrink)

Talk of metaphysical modality as “absolute” is ambiguous, as it appears to convey multiple ideas. Metaphysical possibility is supposedly completely unrestricted or unqualified; metaphysical necessity is unconditional and exceptionless. Moreover, metaphysical modality is thought to be absolute in the sense that it’s real or genuine and the most objective modality: metaphysical possibility and necessity capture ways things could and must have really been. As we disentangle these ideas, certain talk of metaphysical modality qua “absolute” turns out to be misguided. Metaphysical (...) possibility isn't completely unrestricted or most inclusive compared to the other modalities; metaphysical necessity, like all kinds of necessities, is relative to or conditional upon a specific framework of reference. Still, metaphysical modality captures how things could and must have really been most generally because it deals with reality and the nature of things or their essence. That’s the chief interest of metaphysics. Arguments against the alleged absoluteness of metaphysical modality may not thereby undermine its philosophical significance. (shrink)

In ‘The Varieties of Necessity’ Fine presents purported counterexamples to the view that a proposition is a naturally necessary truth if and only if it is logically necessary relative to or conditional upon the basic truths about the status and distribution of natural kinds, properties and relations. The aim of this article is to defend the view that natural necessity is relative necessity, and the general idea that we can define other kinds of necessity as relative, against Fine's criticisms.

What is the function of modal judgment? Why do we make judgments of possibility and necessity? Or are such judgments, in fact, dispensable? This paper introduces and develops an answer to these questions based on Kant’s remarks in section 76 of the Critique of Judgment. Here, Kant appears to argue the following: that a capacity to make modal judgments using modal concepts is required for a capacity for objective representation, in light of our split cognitive architecture. This split cognitive architecture (...) leaves room for a mismatch between our concepts and intuitions and, Kant argues, that is why we need modal concepts and modal judgments. In this paper, I develop this account of the function of modal judgment and to explore the extent to which it may improve upon contemporary alternatives. I focus on one particularly important challenge for the account: to explain why a distinction between the actual and the possible, rather than merely a distinction between the actual and the non-actual, is required. In order to answer this question, I supplement the account with a particular way of thinking about objectivity. (shrink)

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)

An important task for metaphysicians and philosophers of science is to account for laws of nature – in particular, how they distinguish themselves from ‘mere’ regularities, and the modal force they are endowed with, ‘natural necessity’. Dispositional essentialism about laws is roughly the view that laws distinguish themselves by being grounded in the essences of natural entities. This paper does not primarily concern how essentialism compares to its main rivals – Humeanism and Armstrongeanism. Rather, it distinguishes and comparatively assesses various (...) brands of essentialism – which mainly differ as to where exactly they take laws to find their essentialist sources, and what they take to be the targets of laws, namely what they apply to. Yet, this internal comparison is not unrelated to the more general debate about laws: the main criteria with which I compare these essentialist views concern how they can deal with some of the main objections faced by essentialism in general, and how they can keep what is arguably the main intuitive advantage of essentialism over its rivals. Thus, the paper also concerns the relative position of essentialism in the larger debate about laws – ultimately bringing support to it. (shrink)

A common feature of all standard theories of the laws of nature is that they are "absolutist": They take laws to be either all metaphysically necessary or all contingent. Science, however, gives us reason to think that there are laws of both kinds, suggesting that standard theories should make way for "non-absolutist" alternatives: theories which accommodate laws of both modal statuses. In this paper, we set out three explanatory challenges for any candidate non-absolutist theory and discuss the prospects of the (...) two extant candidates in light of these challenges. We then develop our own non-absolutist theory, the essentialist DTA account, which combines the nomic-necessitation or DTA account with an essentialist approach to metaphysical modality in order to meet the three explanatory challenges. Finally, we argue that the distinction between kinematical and dynamical laws found in physical theories supports both non-absolutism in general and our proposed essentialist DTA view in particular. (shrink)

It is widely accepted that necessity comes in different varieties, often called ‘kinds': metaphysical necessity, logical necessity, natural necessity, conceptual necessity, moral necessity, to name but a few – and the same goes for the varieties of possibility. What is usually not fully appreciated, however, is that modal variety is not simply ‘unidimensional': it does not only involve one main variable – kind, whose values are the particular kinds of necessity. Rather, I argue, it is ‘bidimensional', involving two distinct variables (...) – domain and strength. In the first part of the paper, I introduce and develop the proposed bidimensional picture of modal variety, defending it against the common, unidimensional one. In the second part, I consider how the main available accounts of necessities and their relations rely, at least to a significant extent, on the latter picture, pointing out important limitations that they face as a result. I also show how, accordingly, alternative accounts based on a clear and systematic distinction between domain and strength would overcome those limitations. I conclude that, beyond the particular bidimensionalist view defended, our understanding of the modal realm may benefit from more direct debate on whether and how it is multidimensional. (shrink)

The problem of the source of necessity is the problem of explaining what makes necessary truths necessarily true. Simon Blackburn has presented a dilemma intended to show that any reductive, realist account of the source of necessity is bound to fail. Although Blackburn's dilemma faces serious problems, reflection on the form of explanations of necessities reveals that a revised dilemma succeeds in defeating any reductive account of the source of necessity. The lesson is that necessity is metaphysically primitive and irreducible.

This paper discusses some serious difficulties for what we shall call the standard account of various kinds of relative necessity, according to which any given kind of relative necessity may be defined by a strict conditional - necessarily, if C then p - where C is a suitable constant proposition, such as a conjunction of physical laws. We argue, with the help of Humberstone, that the standard account has several unpalatable consequences. We argue that Humberstone’s alternative account has certain disadvantages, (...) and offer another - considerably simpler - solution. (shrink)

This paper defends a deflationary conception of properties, according to which a property exists if and only if there could be a predicate with appropriate satisfaction conditions. I argue that purely general properties and relations necessarily exist and discuss the bearing of this conception of properties on the interpretation of higher-order logic and on Quine's charge that higher-order logic is ‘set theory in sheep's clothing’. On my approach, the usual semantics involves a false assimilation of the logic to set theory. (...) I conclude with remarks about implications for the programme of founding mathematical theories in higher-order logic plus abstraction principles. (shrink)

We present four classical theories of counterpossibles that combine modalities and counterfactuals. Two theories are anti-vacuist and forbid vacuously true counterfactuals, two are quasi-vacuist and allow counterfactuals to be vacuously true when their antecedent is not only impossible, but also inconceivable. The theories vary on how they restrict the interaction of modalities and counterfactuals. We provide a logical cartography with precise acceptable boundaries, illustrating to what extent nonvacuism about counterpossibles can be reconciled with classical logic.

There are many modal epistemologies available to us. Which should we endorse? According to Bob Hale, we can start to answer this question by examining the architecture of modal knowledge. That is, we can try to decide between the following claims: knowing that p is possible is essentially a matter of having a well-founded belief that there are no conflicting necessities—a necessity-based approach—and knowing that p is necessary is essentially a matter of having a well-founded belief that there are no (...) conflicting possibilities—a possibility-based approach. Hale argues for the first of these claims, but I contend that his arguments fail. However, it doesn't follow that we should endorse a possibility-based approach. I repurpose Hale's arguments to show those who would endorse possibility-based approaches need to say more about our modal knowledge concerning logic and mathematics; if they can't, then they ought to endorse a hybrid modal epistemology that doesn't give priority to one modality across the board. Additionally, those who endorse possibility-based views may be committed to Peter van Inwagen's modal skepticism. (shrink)

I argue that a pragmatic scepticism about metaphysical modality is a perfectly reasonable position to maintain. I then illustrate the difficulties and limitations associated with some strategies for defeating such scepticism. These strategies appeal to associations between metaphysical modality and the following: objective probability, counterfactuals and distinctive explanatory value.

McFetridge (in Logical necessity and other essays . London: Blackwell, 1990 ) suggests that to treat a proposition as logically necessary—to believe a proposition logically necessary, and to manifest that belief—is a matter of preparedness to deploy that proposition as a premise in reasoning from any supposition. We consider whether a suggestion in that spirit can be generalized to cover all cases of absolute necessity, both logical and non-logical, and we conclude that it can. In Sect. 2, we explain the (...) significance that such an account of manifestation of belief in absolute necessity has for the prospects of a non-realist theory of modality. In Sect. 3, we offer a sympathetic articulation of the detail that underlies the McFetridge conception of belief in logical necessity. In Sects. 4 and 5, we show that the conception so articulated will not generalize to encompass all cases of belief in absolute necessity and proceed to offer a remedy. Our proposal is based upon a distinction between two kinds of suppositional act: A-supposing and C-supposing (Sect. 6). In Sect. 7, we then explain and defend our central thesis: (roughly) that (manifestation of) belief in absolute necessity is a matter of preparedness to deploy as a premise in reasoning under any C-supposition. Finally, we indicate that there is some promise in the parallel thesis that manifestation of the treatment of a proposition as a priori is a matter of preparedness to deploy as a premise in reasoning under any A-supposition (Sect. 8). (shrink)

In `Essence and Modality', Kit Fine proposes that for a proposition to be metaphysically necessary is for it to be true in virtue of the nature of all objects whatsoever. Call this view Fine's Thesis. This paper is a study of Fine's Thesis in the context of Fine's logic of essence (LE). Fine himself has offered his most elaborate defense of the thesis in the context of LE. His defense rests on the widely shared assumption that metaphysical necessity obeys the (...) laws of the modal logic S5. In order to get S5 for metaphysical necessity, he assumes a controversial principle about the nature of all objects. I will show that the addition of this principle to his original system E5 leads to inconsistency with an independently plausible principle about essence. In response, I develop a theory that avoids this inconsistency while allowing us to maintain S5 for meta- physical necessity. However, I conclude that our investigation of Fine's Thesis in the context of LE motivates the revisionary conclusion that metaphysical necessity obeys the principles of the modal logic S4, but not those of S5. I argue that this constitutes a distinctively essentialist challenge to the received view that the logic of metaphysical necessity is S5. (shrink)

What is the relation between metaphysical necessity and essence? This paper defends the view that the relation is one of identity: metaphysical necessity is a special case of essence. My argument consists in showing that the best joint theory of essence and metaphysical necessity is one in which metaphysical necessity is just a special case of essence. The argument is made against the backdrop of a novel, higher-order logic of essence, whose core features are introduced in the first part of (...) the paper. The second part investigates the relation between metaphysical necessity and essence in the context of HLE. Reductive hypotheses are among the most natural hypotheses to be explored in the context of HLE. But they also have to be weighed against their non-reductive rivals. I investigate three different reductive hypotheses and argue that two of them fare better than their non-reductive rivals: they are simpler, more natural, and more systematic. Specifically, I argue that one candidate reduction, according to which metaphysical necessity is truth in virtue of the nature of all propositions, is superior to the others, including one proposed by Kit Fine, according to which metaphysical necessity is truth in virtue of the nature of all objects. The paper concludes by offering some reasons to think that the best joint theory of essence and metaphysical necessity is one in which the logic of metaphysical necessity includes S4, but not S5. (shrink)

In his influential paper ‘‘Essence and Modality’’, Kit Fine argues that no account of essence framed in terms of metaphysical necessity is possible, and that it is rather metaphysical necessity which is to be understood in terms of essence. On his account, the concept of essence is primitive, and for a proposition to be metaphysically necessary is for it to be true in virtue of the nature of all things. Fine also proposes a reduction of conceptual and logical necessity in (...) the same vein: a conceptual necessity is a proposition true in virtue of the nature of all concepts, and a logical necessity a proposition true in virtue of the nature of all logical concepts. I argue that the plausibility of Fine's view crucially requires that certain apparent explanatory links between essentialist facts be admitted and accounted for, and I make a suggestion about how this can be done. I then argue against the reductions of conceptual and logical necessity proposed by Fine and suggest alternative reductions, which remain nevertheless Finean in spirit. (shrink)

In this article, we discuss a simple argument that modal metaphysics is misconceived, and responses to it. Unlike Quine's, this argument begins with the simple observation that there are different candidate interpretations of the predicate ‘could have been the case’. This is analogous to the observation that there are different candidate interpretations of the predicate ‘is a member of’. The argument then infers that the search for metaphysical necessities is misguided in much the way the ‘set-theoretic pluralist’ claims that the (...) search for the true axioms of set theory is. We show that the obvious responses to this argument fail. However, a new response has emerged that purports to prove, from higher-order logical principles, that metaphysical possibility is the broadest kind of possibility applying to propositions, and is to that extent special. We distill two lines of reasoning from the literature, and argue that their import depends on premises that any ‘modal pluralist’ should deny. Both presuppose that there is a unique typed hierarchy, which is what the modal pluralist, in the context of higher-order logic, should disavow. In other words, both presupposes that there is a unique candidate for what higher-order claims could mean. We consider the worry that, in a higher-order setting, modal pluralism faces an insuperable problem of articulation, collapses into modal monism, is vulnerable to the Russell-Myhill paradox, or even contravenes the truism that there is a unique actual world, and argue that these worries are misplaced. We also sketch the bearing of the resulting ‘Higher-Order Pluralism’ on the theory of content. One theme of the discussion is that, if Higher-Order Pluralism is correct, then there is no fixed metatheory from which to characterize higher-order reality. (shrink)

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)

It is widely alleged that metaphysical possibility is “absolute” possibility Conceivability and possibility, Clarendon, Oxford, 2002, p 16; Stalnaker, in: Stalnaker Ways a world might be: metaphysical and anti-metaphysical essays, Oxford University Press, Oxford, 2003, pp 201–215; Williamson in Can J Philos 46:453–492, 2016). Kripke calls metaphysical necessity “necessity in the highest degree”. Van Inwagen claims that if P is metaphysically possible, then it is possible “tout court. Possible simpliciter. Possible period…. possib without qualification.” And Stalnaker writes, “we can agree (...) with Frank Jackson, David Chalmers, Saul Kripke, David Lewis, and most others who allow themselves to talk about possible worlds at all, that metaphysical necessity is necessity in the widest sense.” What exactly does the thesis that metaphysical possibility is absolute amount to? Is it true? In this article, I argue that, assuming that the thesis is not merely terminological, and lacking in any metaphysical interest, it is an article of faith. I conclude with the suggestion that metaphysical possibility may lack the metaphysical significance that is widely attributed to it. (shrink)

A natural language argument may be valid in at least two nonequivalent senses: it may be interpretationally or representationally valid (Etchemendy in The concept of logical consequence. Harvard University Press, Cambridge, 1990). Interpretational and representational validity can both be formally exhibited by classical first-order logic. However, as these two notions of informal validity differ extensionally and first-order logic fixes one determinate extension for the notion of formal validity (or consequence), some arguments must be formalized by unrelated nonequivalent formalizations in order (...) to formally account for their interpretational or representational validity, respectively. As a consequence, arguments must be formalized subject to different criteria of adequate formalization depending on which variant of informal validity is to be revealed. This paper develops different criteria that formalizations of an argument have to satisfy in order to exhibit the latter’s interpretational or representational validity. (shrink)

In this paper the logic of broad necessity is explored. Definitions of what it means for one modality to be broader than another are formulated, and it is proven, in the context of higher-order logic, that there is a broadest necessity, settling one of the central questions of this investigation. It is shown, moreover, that it is possible to give a reductive analysis of this necessity in extensional language. This relates more generally to a conjecture that it is not possible (...) to define intensional connectives from extensional notions. This conjecture is formulated precisely in higher-order logic, and concrete cases in which it fails are examined. The paper ends with a discussion of the logic of broad necessity. It is shown that the logic of broad necessity is a normal modal logic between S4 and Triv, and that it is consistent with a natural axiomatic system of higher-order logic that it is exactly S4. Some philosophical reasons to think that the logic of broad necessity does not include the S5 principle are given. (shrink)

On the model-theoretic account, a sentence is logically true just in case it is true on all possible semantic interpretations. We dierentiate four ways one can interpret the modality 'possible' in this definition, and argue that one of these readings is not subject to the criticism levelled against the model-theoretic account by Etchemendy. By explicating the four readings we also draw some consequences for what linguistic evidence a selection of logical theories should be sensitive to.

Modality and Anti-Metaphysics critically examines the most prominent approaches to modality among analytic philosophers in the twentieth century, including essentialism. Defending both the project of metaphysics and the essentialist position that metaphysical modality is conceptually and ontologically primitive, Stephen McLeod argues that the logical positivists did not succeed in banishing metaphysical modality from their own theoretical apparatus and he offers an original defence of metaphysics against their advocacy of its elimination. -/- Seeking to assuage the sceptical worries which underlie modal (...) anti-realism, McLeod provides an original contribution to essentialist epistemology, engaging with current debates about modality and suggesting that standard essentialist approaches to some issues in the philosophies of logic and language require revision. -/- This book offers valuable insights to professional philosophers, postgraduates and advanced undergraduates interested in metaphysics, philosophy of logic or the history of twentieth-century analytic philosophy. (shrink)

Logical monism is the view that there is ‘One True Logic’. This is the default position, against which pluralists react. If there were not ‘One True Logic’, it is hard to see how there could be one true theory of anything. A theory is closed under a logic! But what is logical monism? In this article, I consider semantic, logical, modal, scientific, and metaphysical proposals. I argue that, on no ‘factualist’ analysis (according to which ‘there is One True Logic’ expresses (...) a factual claim, rather than an attitude like approval), does the doctrine have both metaphysical and methodological import. Metaphysically, logics abound. Methodologically, what to infer from what is not settled by the facts, even the normative ones. I conclude that the only interesting sense in which there could be One True Logic is noncognitive. The same may be true of monism about normative areas, like moral, epistemic, and prudential ones, generally. (shrink)

⦿ In my dissertation I introduce, motivate and take the first steps in the implementation of, the project of naturalising modal metaphysics: the transformation of the field into a chapter of the philosophy of science rather than speculative, autonomous metaphysics. -/- ⦿ In the introduction, I explain the concept of naturalisation that I apply throughout the dissertation, which I argue to be an improvement on Ladyman and Ross' proposal for naturalised metaphysics. I also object to Williamson's proposal that modal metaphysics (...) --- or some view in the area --- is already a quasi-scientific discipline. -/- ⦿ Recently, some philosophers have argued that the notion of metaphysical modality is as ill defined as to be of little theoretical utility. In the second chapter I intend to contribute to such skepticism. First, I observe that each of the proposed marks of the concept, except for factivity, is highly controversial; thus, its logical structure is deeply obscure. With the failure of the "first principles" approach, I examine the paradigmatic intended applications of the concept, and argue that each makes it a device for a very specific and controversial project: a device, therefore, for which a naturalist will find no use for. I conclude that there is no well-defined or theoretically useful notion of objective necessity other than logical or physical necessity, and I suggest that naturalising modal metaphysics can provide more stable methodological foundations. -/- ⦿ In the third chapter I answer a possible objection against the in-principle viability of the project: that the concept of metaphysical modality cannot be understood through the philosophical analysis of any scientific theory, since metaphysical necessity "transcends'' natural necessity, and science only deals with the latter. I argue that the most important arguments for this transcendence thesis fail or face problems that, as of today, remain unsolved. -/- ⦿ Call the idea that science doesn't need modality, "demodalism''. Demodalism is a first step in a naturalistic argument for modal antirealism. In the fourth chapter I examine six versions of demodalism to explain why a family of formalisms, that I call "spaces of possibility'', are (i) used in a quasi-ubiquitous way in mathematised sciences (I provide examples from theoretical computer science to microeconomics), (ii) scientifically interpreted in modal terms, and (iii) used for at least six important tasks: (1) defining laws and theories; (2) defining important concepts from different sciences (I give several examples); (3) making essential classifications; (4) providing different types of explanations; (5) providing the connection between theory and statistics, and (6) understanding the transition between a theory and its successor (as is the case with quantisation). -/- ⦿ In fifth chapter I propose and defend a naturalised modal ontology. This is a realism about modal structure: my realism about constraints. The modal structure of a system are the relationships between its possible states and between its possible states and those of other systems. It is given by the plurality of restrictions to which said system is subject. A constraint is a factor that explains the impossibility of a class of states; I explain this concept further. First, I defend my point of view by rejecting some of its main rivals: constructive empiricism, Humean conventionalism, and wave function realism, as they fail to make sense of quantum chaos. This is because the field requires the notion of objective modal structure, and the mentioned views have trouble explaining the modal facts of quantum dynamics. Then, I argue that constraint realism supersedes these views in the context of Bohm's standard theory and mechanics, and underpins the study of quantum chaos. Finally, I consider and reject two possible problems for my point of view. -/- ⦿ A central concern of modal metaphysicians has been to understand the logical system that best characterises necessity. In the sixth chapter I intend to recover the logical project applied to my naturalistic modal metaphysics. Scientists and philosophers of science accept different degrees of physical necessity, ranging from purely mathematically necessary facts that restrict physical behaviour, to kinetic principles, to particular dynamical constraints. I argue that this motivates a multimodal approach to modal logic, and that the time dependence of dynamics motivates a logic of historical necessity. I propose multimodal propositional (classical) logics for Bohmian mechanics and the Everettian theory of many divergent worlds, and I close with a criticism of Williamson's approach to the logic of state spaces of dynamic systems. (shrink)

Aim of this paper is to analyse and assess two divergent understandings of metaphysical modality. On one hand, according to the absolutist conception, metaphysical modality is the extreme variety of objective modality and can be characterised in terms of all the varieties of objective modality: for example, p is metaphysically necessary if and only if p is necessary for every variety of objective necessity. The absolutist conception can also be framed in terms of counterfactual inevitability. On the other hand, according (...) to the essentialist conception of metaphysical modality, p is metaphysically necessary if and only if the truth of p is grounded by the essences of some entities. Based on the analysis of these two conceptions, I show that possible worlds are not helpful in characterising metaphysical modality. I finally suggest that in the light of a general principle about philosophical terminology, the essentialist conception has an edge over the absolutist one. (shrink)

Languages involving modalities and languages involving vagueness have each been thoroughly studied. On the other hand, virtually nothing has been said about the interaction of modality and vagueness. This paper aims to start filling that gap. Section 1 is a discussion of various possible sources of vague modality. Section 2 puts forward a model theory for a quantified language with operators for modality and vagueness. The model theory is followed by a discussion of the resulting logic. In Section 3, the (...) framework will permit us to address a puzzle raised by Elizabeth Barnes and Robert Williams. (shrink)