Consequence is at the heart of logic; an account of consequence, of what follows from what, offers a vital tool in the evaluation of arguments. Since philosophy itself proceeds by way of argument and inference, a clear view of what logical consequence amounts to is of central importance to the whole discipline. In this book JC Beall and Greg Restall present and defend what thay call logical pluralism, the view that there is more than one genuine deductive consequence relation, a (...) position which has profound implications for many linguists as well as for philosophers. We should not search for one true logic, since there are many. (shrink)

Ontological pluralism is the view that there are different fundamental ways of being. Trenton Merricks has recently raised three objections to combining pluralism with a generic way of being enjoyed by absolutely everything there is: first, that the resulting view contradicts the pluralist’s core intuition; second, that it is especially vulnerable to the charge—due to Peter van Inwagen—that it posits a difference in being where there is simply a difference in kind; and, third, that it is in tension with various (...) historically influential motivations for pluralism. I reply to each of these objections in turn. My replies will help to bring out the true nature of the pluralist’s basic commitments. (shrink)

Argument that priority monism is best understood as being a contingent thesis.

Eternalism, the view that what we regard locally as being located in the past, the present and the future equally exists, is the best ontological account of temporal existence in line with special and general relativity. However, special and general relativity are not fundamental theories and several research programs aim at finding a more fundamental theory of quantum gravity weaving together all we know from relativistic physics and quantum physics. Interestingly, some of these approaches assert that time is not fundamental. (...) If time is not fundamental, what does it entail for eternalism and the standard debate over existence in time? First, I will argue that the non-fundamentality of time to be found in string theory entails standard eternalism. Second, I will argue that the non-fundamentality of time to be found in loop quantum gravity entails atemporal eternalism, namely a novel position in the spirit of standard eternalism. (shrink)

This article includes a basic overview of possible world semantics and a relatively comprehensive overview of three central philosophical conceptions of possible worlds: Concretism (represented chiefly by Lewis), Abstractionism (represented chiefly by Plantinga), and Combinatorialism (represented chiefly by Armstrong).

In this chapter, I survey what I call Lewisian approaches to modality: approaches that analyze modality in terms of concrete possible worlds and their parts. I take the following four theses to be characteristic of Lewisian approaches to modality. (1) There is no primitive modality. (2) There exists a plurality of concrete possible worlds. (3) Actuality is an indexical concept. (4) Modality de re is to be analyzed in terms of counterparts, not transworld identity. After an introductory section in which (...) I motivate analyzing modality in terms of possible worlds, I devote one section to each of these four theses. For each thesis, I take Lewis’s interpretation and defense as my starting point. I then consider and endorse alternative ways of accepting the thesis, some of which disagree substantially with Lewis’s interpretation or defense. There is more than one way to be a Lewisian about modality. (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.

According to David Lewis, a realist about possible worlds must hold that actuality is relative: the worlds are ontologically all on a par; the actual and the merely possible differ, not absolutely, but in how they relate to us. Call this 'Lewisian realism'. The alternative, 'Leibnizian realism', holds that actuality is an absolute property that marks a distinction in ontological status. Lewis presents two arguments against Leibnizian realism. First, he argues that the Leibnizian realist cannot account for the contingency of (...) actuality. Second, he argues that the Leibnizian realist cannot explain why skepticism about one's own actuality is absurd. In this paper, I mount a defense of Leibnizian realism. (shrink)

God is traditionally taken to be a perfect being, and the creator and sustainer of all that is. So, if theism is true, what sort of world should we expect? To answer this question, we need an account of the array of possible worlds from which God is said to choose. It seems that either there is (a) exactly one best possible world; or (b) more than one unsurpassable world; or (c) an infinite hierarchy of increasingly better worlds. Influential arguments (...) for atheism have been advanced on each hierarchy, and these jointly comprise a daunting trilemma for theism. In this paper, I argue that if theism is true, we should expect the actual world to be a multiverse comprised of all and only those universes which are worthy of creation and sustenance. I further argue that this multiverse is the unique best of all possible worlds. Finally, I explain how his unconventional view bears on the trilemma for theism. (shrink)

David Wallace has given a decision-theoretic argument for the Born Rule in the context of Everettian quantum mechanics. This approach promises to resolve some long-standing problems with probability in EQM, but it has faced plenty of resistance. One kind of objection charges that the requisite notion of decision-theoretic uncertainty is unavailable in the Everettian picture, so that the argument cannot gain any traction; another kind of objection grants the proof’s applicability and targets the premises. In this article I propose some (...) novel principles connecting the physics of EQM with the metaphysics of modality, and argue that in the resulting framework the incoherence problem does not arise. These principles also help to justify one of the most controversial premises of Wallace’s argument, ‘branching indifference’. Absent any a priori reason to align the metaphysics with the physics in some other way, the proposed principles can be adopted on grounds of theoretical utility. The upshot is that Everettians can, after all, make clear sense of objective probability. 1 Introduction2 Setup3 Individualism versus Collectivism4 The Ingredients of Indexicalism5 Indexicalism and Incoherence5.1 The trivialization problem5.2 The uncertainty problem6 Indexicalism and Branching Indifference6.1 Introducing branching indifference6.2 The pragmatic defence of branching indifference6.3 The non-existence defence of branching indifference6.4 The indexicalist defence of branching indifference7 Conclusion. (shrink)

I present an internal problem for David Lewis’s genuine modal realism. My aim is to show that his analysis of modality is inconsistent with his metaphysics. I consider several ways of modifying the Lewisian analysis of modality, but argue that none are successful. I argue that the problem also affects theories related to genuine modal realism, including the stage theory of persistence and modal fictionalism.

I propose an account truthmaking that provides truthmakers for negative truths. The account replaces Truthmaker Necessitarianism with a "Duplication Principle", according to which a suitable entity T is a truthmaker for a proposition P just in case the existence of an appropriate counterpart of T entails the truth of P, where the counterpart relation is cashed out in terms of qualitative duplication. My account captures an intuitive notion of truthmakers as "things the way they are", validates two appealing principles about (...) entailment and containment proposed by David Armstrong, and invalidates the controversial Disjunction Thesis. (shrink)

I am a realist of a metaphysical stripe. I believe in an immense realm of "modal" and "abstract" entities, of entities that are neither part of, nor stand in any causal relation to, the actual, concrete world. For starters: I believe in possible worlds and individuals; in propositions, properties, and relations (both abundantly and sparsely conceived); in mathematical objects and structures; and in sets (or classes) of whatever I believe in. Call these sorts of entity, and the reality they comprise, (...) metaphysical. In contrast, call the actual, concrete entities, and the reality they comprise, physical. Physical and metaphysical reality together comprise all that there is. In this paper, it is not my aim to defend realism about any particular metaphysical sort of entity. Rather, I ask quite generally whether and how any brand of realism about metaphysical sorts of entity could be justified? (shrink)

Lewisian Genuine Realism about possible worlds is often deemed unable to accommodate impossible worlds and reap the benefits that these bestow to rival theories. This thesis explores two alternative extensions of GR into the terrain of impossible worlds. It is divided in six chapters. Chapter I outlines Lewis’ theory, the motivations for impossible worlds, and the central problem that such worlds present for GR: How can GR even understand the notion of an impossible world, given Lewis’ reductive theoretical framework? Since (...) the desideratum is to incorporate impossible worlds into GR without compromising Lewis’ reductive analysis of modality, Chapter II defends that analysis against objections. The rest of the thesis is devoted to incorporating impossible worlds into GR. Chapter III explores GR-friendly impossible worlds in the form of set-theoretic constructions out of genuine possibilia. Then, Chapters IV-VI venture into concrete impossible worlds. Chapter IV addresses Lewis’ objection against such worlds, to the effect that contradictions true at impossible worlds amount to true contradictions tout court. I argue that even if so, the relevant contradictions are only ever about the non-actual, and that Lewis’ argument relies on a premise that cannot be nonquestion- beggingly upheld in the face of genuine impossible worlds in any case. Chapter V proposes that Lewis’ reductive analysis can be preserved, even in the face of genuine impossibilia, if we differentiate the impossible from the possible by means of accessibility relations, understood non-modally in terms of similarity. Finally, Chapter VI counters objections to the effect that there are certain impossibilities, formulated in Lewis’ theoretical language, which genuine impossibilia should, but cannot, represent. I conclude that Genuine Realism is still very much in the running when the discussion turns to impossible worlds. (shrink)

Priority monism (hereafter, ‘monism’) is the view that there exists one fundamental entity—the world—and that all other objects that exist (a set of objects typically taken to include tables, chairs, and the whole menagerie of everyday items) are merely derivative. Jonathan Schaffer has defended monism in its current guise, across a range of papers. Each paper looks to add something to the monistic picture of the world. In this paper we argue that monism—as Schaffer describes it—is false. To do so (...) we develop an ‘island universe’ argument against Schaffer's monistic theory. (shrink)

According to the No Alternate Possibilities argument, if time passes then the rate at which it passes could be different but time cannot pass at different rates, and hence time cannot pass. Typically, defenders of the NAP argument have focussed on defending premise, and have taken the truth of for granted: they accept the orthodox view of rate necessitarianism. In this paper we argue that the defender of the NAP argument needs to turn her attention to. We describe a series (...) of worlds that appear to contain differential passage: worlds where time passes at different rates in different subregions. If the NAP argument is to succeed, rate necessitarians must show that each of these worlds is either metaphysically impossible, or does not contain differential passage. (shrink)

Presentism is typically characterised as the thesis that everything is present, and therefore there are no dinosaurs or Martian presidential inaugurations. Putting aside the vexed question of exactly what it is to be present in this context, this thesis seems quite straightforward. However, a number of authors—such as Merricks, Lombard, Meyer, Tallant and Sakon —have argued that Presentism so characterised is either trivially true or false even by Presentist lights. This is the so-called Triviality Argument against Presentism. In this paper (...) I show that three of the four premises of the Triviality Argument are plausibly false. I conclude that Presentists have nothing to fear from the Triviality Argument. (shrink)

Theories that use expected utility maximization to evaluate acts have difficulty handling cases with infinitely many utility contributions. In this paper I present and motivate a way of modifying such theories to deal with these cases, employing what I call “Direct Difference Taking”. This proposal has a number of desirable features: it’s natural and well-motivated, it satisfies natural dominance intuitions, and it yields plausible prescriptions in a wide range of cases. I then compare my account to the most plausible alternative, (...) a proposal offered by Arntzenius :31–58, 2014). I argue that while Arntzenius’s proposal has many attractive features, it runs into a number of problems which Direct Difference Taking avoids. (shrink)

The distinction between qualitative and non-qualitative properties should be familiar from discussions of the principle of the identity of indiscernibles: two otherwise exactly similar individuals, Castor and Pollux, might share all their qualitative properties yet differ with respect to their non-qualitative properties—for while Castor has the property being identical to Castor, Pollux does not. But while this distinction is familiar, there has not been much critical attention devoted to spelling out its precise nature. I argue that the class of non-qualitative (...) properties is broader than it is often taken to be. When properly construed, it will not only include properties such as being identical to Castor, which somehow make reference to particular individuals, it will also include more general properties such as identity, composition, set membership, as well as various peculiarly ontological properties. Given that some of these more general properties help to explain objective similarity, we have reason to believe that there are fundamental non-qualitative properties. (shrink)

The question of what truths are necessary in the broadest possible sense is a difficult one to answer, as is the question of what the limits are to what is possible. (Most people would see these two questions as different sides of the same coin, of course, since many think the question of what is possible is just the question of what is not necessarily ruled out). We have three general sorts of strategies for determining whether something is necessary (or (...) possible). We can identify it in a class that we were previously sure was a class of things that are necessary – we might show it is a theorem of a logical system that we have confidence in, or that the sentence appears to be true simply in virtue of the meanings of the words, or that it is a true statement involving names or about natural kinds of the “necessary a posteriori” sort discussed by Kripke and Putnam, and there are perhaps other classes of claims which we are prepared to accept are necessary if true.1 Likewise, we might establish the possibility of something occurring by reference to a class of well-established or uncontroversial possibilities: e.g. we are inclined to think that it is possible (in the broadest sense) for an event to occur in the future if one of the same kind has occurred in the past. (shrink)

This paper outlines a ‘perceptual account’ of depiction. It centrally contrasts with experiential accounts of depiction in that seeing something in a picture is understood as a visual experience of something present in the picture, rather than as a visual experience of something absent. The experience of a picture is in this respect akin to a veridical rather than hallucinatory perceptual experience on a perceptual account. Thus, the central selling-point of a perceptual account is that it allows taking at face (...) value the intuitive claim that we see things in pictures. Preserving this claim has a potential cost, however: we need to postulate that some kind of thing, T, is present in the realm of the picture, and it is not straightforward to find a plausible type of entity to play this role. The paper examines three alternative choices of T; T may be a material object, a visual appearance or a universal. (shrink)

This paper discusses the nature of, problems for, and benefits delivered by fictionalist strategies in metaphysics.

_The Metaphysics of Perfect Beings_ addresses the problems an Anselmian perfect being faces in contexts involving unlimited options. Recent advances in the theory of vagueness, the metaphysics of multiverses and hyperspace, the theory of dynamic or sequential choice, the logic of moral and rational dilemmas, and metaethical theory provide the resources to formulate the new challenges and the Anselmian responses with an unusual degree of precision. Almeida shows that the challenges arising in the unusual contexts involving unlimited options sometimes produce (...) metaphysical surprise. (shrink)

This article sits at a point of intersection between the philosophy of physics and the metaphysics of modality. There are clear similarities between Everettian quantum mechanics and various modal metaphysical theories, but there have hitherto been few attempts at exploring how the two topics relate. In this article, I build on a series of recent papers by Wilson ([2011], [2012], [2013]), who argues that Everettian quantum mechanics’ connections with traditional modal metaphysics are vital in defending it against objections. I show (...) that Wilson’s preferred version of Everettian quantum mechanics has two problems. First, it is unable to account for the contingency of various intuitively contingent modal claims. Second, it fails to yield intuitive truth values on modal claims about the number of branches in a given Everettian multiverse. Since modal claims about branch number are instrumental in decision-theoretic solutions to Everettian quantum mechanics’ problem(s) with probability, this second problem has wider dialectical implications. I suggest amendments to the underlying metaphysics that overcome these problems. The result is a more robust version of Everettian quantum mechanics. (shrink)

Some properties such as having a beard and being a philosopher are intuitively qualitative, while other properties such as being identical to Plato and being a student of Socrates are intuitively non-qualitative. It is often assumed that, necessarily, a property is qualitative if and only if it can be designated descriptively without the aid of directly referential devices. I argue that this linguistic thesis fails in both directions: there might be non-qualitative properties that can be designated descriptively, and there appear (...) to be qualitative properties that can only be designated directly. I conclude that while the linguistic thesis is ultimately untenable as stated, it can be plausibly recast as a thesis about our concepts rather than the properties they designate. (shrink)

A number of philosophers have recently found it congenial to talk in terms of grounding. Grounding discourse features grounding sentences that are answers to questions about what grounds what. The goal of this article is to explore and defend a counterpart-theoretic interpretation of grounding discourse. We are familiar with David Lewis's applications of the method of counterpart theory to de re modal discourse. Counterpart-theoretic interpretations of de re modal idioms and grounding sentences share similar motivations, mechanisms, and applications. I shall (...) explain my motivations and describe two applications of a counterpart theory for grounding discourse. But, in this article, my main focus is on counterpart-theoretic mechanisms. (shrink)

According to the Truthmaker Principle: every truth has a truthmaker. Attempts to come to grips with the Truthmaker Principle played a prominent role in Lewis’s metaphysical writings over the last fifteen years of his career. Although Lewis agreed that the truth of propositions must somehow be ontologically grounded, the Truthmaker Principle was too strong: it conflicted with two of Lewis’s most fundamental metaphysical assumptions, the uniqueness of composition and the Humean denial of necessary connections. Lewis endorsed instead a weaker principle: (...) Truth Supervenes on Being. But towards the end of his career, he changed course, noting that his critique of the Truthmaker Principle rested on essentialist assumptions that he, as a counterpart theorist, does not accept. Once freed from those assumptions, a counterpart theorist can accept the Truthmaker Principle after all without buying into unmereological composition and mysterious necessary connections. (shrink)

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

Possibilism—the view that there are non-actual, merely possible entities—is a surprisingly resilient doctrine.1 One particularly hardy strand of possibilism—the modal realism championed by David Lewis—continues to attract both foes who seek to demonstrate its falsity (or at least stare its advocates into apostasy) and friends who hope to defend modal realism (or, when necessary, modify modal realism so as to avoid problematic objections).2 Although I am neither a foe nor friend of modal realism (but some of my best friends are!), (...) like many I continue to be fascinated by the doctrine. (shrink)

This paper proposes a new reductive theory of modality, called the moodless theory of modality. This theory, and not modal realism, is the closest modal analogue of the tenseless theory of time. So, if the tenseless theory is true, and the temporality–modality analogy is good, it is the moodless theory that follows. I also argue that the moodless theory, considered on its own, is better than modal realism: arguments often thought to be decisive against modal realism are weak against it.

Gideon Rosen’s [1990 Modal fictionalism. Mind, 99, 327–354] Modal Fictionalist aims to secure the benefits of realism about possible-worlds, whilst avoiding commitment to the existence of any world other than our own. Rosen [1993 A problem for fictionalism about possible worlds. Analysis, 53, 71–81] and Stuart Brock [1993 Modal fictionalism: A response to Rosen. Mind, 102, 147–150] both argue that fictionalism is self-defeating since the fictionalist is tacitly committed to the existence of a plurality of worlds. In this paper, I (...) develop a new strategy for the fictionalist to pursue in response to the Brock–Rosen objection. I begin by arguing that modal fictionalism is best understood as a paraphrase strategy that concerns the propositions that are expressed, in a given context, by modal sentences. I go on to argue that what is interesting about paraphrastic fictionalism is that it allows the fictionalist to accept that the sentence ‘there is a plurality of worlds’ is true without thereby committing her to the existence of a plurality of worlds. I then argue that the paraphrastic fictionalist can appeal to a form of semantic contextualism in order to communicate her status as an anti-realist. Finally, I generalise my conception of fictionalism and argue that Daniel Nolan and John O’Leary-Hawthorne [1996 Reflexive fictionalisms. Analysis, 56, 26–32] are wrong to suggest that the Brock-Rosen objection reveals a structural flaw with all species of fictionalism. (shrink)

Modal primitivists hold that some modal truths are primitively true. They thus seem to face a special epistemological problem: how can primitive modal truths be known? The epistemological objection has not been adequately developed in the literature. I undertake to develop the objection, and then to argue that the best formulation of the epistemological objection targets all realists about modality, rather than the primitivist alone. Furthermore, the moves available to reductionists in response to the objection are also available to primitivists. (...) I conclude by suggesting that extant theories of the epistemology of modality are not sensitive to the question of primitivism versus reductionism. (shrink)

The Forrest-Armstrong argument, as reconfigured by David Lewis, is a reductio against an unrestricted principle of recombination. There is a gap in the argument which Lewis thought could be bridged by an appeal to recombination. After presenting the argument, I show that no plausible principle of recombination can bridge the gap. But other plausible principles of plenitude can bridge the gap, both principles of plenitude for world contents and principles of plenitude for world structures. I conclude that the Forrest-Armstrong argument, (...) when fortified in one of these ways, demands that unrestricted recombination be rejected. The appropriate restriction comes from a consideration of what world structures are possible. I argue that, although there are too many worlds to form a set, for any world, the individuals at that world do form a set. To defend it I invoke a principle of Limitation of Size together with an iterative conception of structure. (shrink)

In this article, I am interested in four versions of what is often referred to as "the Humphrey objection". This objection was initially raised by Kripke against Lewis's modal counterpart theory, so this is where I will start the discussion. As we will see, there is a perfectly good answer to the objection. I will then examine other places where a similar objection can be raised: it can arise in the case of temporal counterpart theory (in fact, it can arise (...) in the case of all kinds of counterpart theories, independently on modal realism), and a very similar worry can also arise against modal realism itself or against an ersatzist theory of possible worlds itself. For similar reasons, in similar situations, a similar objection will arise. What is interesting is that it is not the case that a similar response can be given in all of these similar cases. So, in the end, we will see what dissimilarities there are and how and why they are relevant. In particular, we will see the differences there are between alethic modalities and temporal modalities. In the case of alethic modalities (metaphysical necessity and possibility), the objection can be answered by appealing to the notion of representation, while this does not work very well in the case of temporal modalities. (shrink)

While there is considerable disagreement on the precise nature of material objecthood, it is standardly assumed that material objects must be spatial. In this paper, I provide two arguments against this assumption. The first argument is made from largely a priori considerations about modal plenitude. The possibility of non-spatial material objects follows from commitment to certain plausible principles governing material objecthood and plausible principles regarding modal plenitude. The second argument draws from current philosophical discussions regarding theories of quantum gravity and (...) the emergence of spacetime. When it is appreciated what possible worlds these current theories commit us to, the possibility of non-spatial material objects will follow. Thus, either route will lead us to the possibility of non-spatial material objects. The significance of this result is that we need to revise our accounts of material objecthood to both accommodate these possibilities and the theories that lead to them. (shrink)

In this paper I argue that Modal Realism, the thesis that there exist non-actual possible individuals and worlds, can be made compatible with Metaphysical Nihilism, the thesis that it is possible that nothing concrete exists. Modal Realism as developed by Lewis rules out the possibility of a world where nothing concrete exists and so conflicts with Metaphysical Nihilism. In the paper I argue that Modal Realism can be modified so as to be compatible with Metaphysical Nihilism. Such a modification makes (...) Modal Realism neither incur further theoretical costs nor lose its theoretical benefits. Thus such a modification constitutes an improvement of Modal Realism. (shrink)

In this paper I argue, that if it is metaphysically possible for it to have been the case that nothing existed, then it follows that the right modal logic cannot extend D, ruling out popular modal logics S4 and S5. I provisionally defend the claim that it is possible for nothing to have existed. I then consider the various ways of resisting the conclusion that the right modal logic is weaker than D.

We propose a novel interpretation of Lewis on the analysis of modality that is constructed from primary sources, comprehensive and unprecedented. Our guiding precepts are to distinguish semantics from metaphysics, while respecting the inter-relations between them, and to discern whatever may be special, semantically or metaphysically, about the modal case. Following detailed presentation, we amplify and advocate our interpretation by providing a conforming genealogy of Lewis’s theory of modality and applying it to construct a detailed and newly illuminating version of (...) the Lewisian theory of modality de re. (shrink)

At a first glance, and even at a second one, it seems that if time is linear the threat of determinism is more severe than if time is branching, since in the latter case the future is open in a way it is not in the former one where, so to speak, there exists only one branch – one future. In this paper, I want to give a 'third glance' at this claim. I acknowledge that such a claim is intuitive (...) (this is the first glance) and that it is also meaningfully and interestingly defended in recent literature where branching time is either said to imply indeterminism or at least to be compatible with it. To try to make my third glance as precise and as fleshed out as possible, I shall first concentrate on what 'branching' is or could be, and I shall discuss various versions and interpretations of this view. I shall then (more quickly) turn my attention to what determinism is or could be, and I will distinguish three (well-known) kinds of it – focusing mainly on 'metaphysical determinism'. Having these tools in hand, I will then ask (and answer) the question whether branching time helps with avoiding determinism or not. As we shall see, it is incorrect to think that under the branching hypothesis the threat of determinism is any smaller – rather, I will argue that if one has reasons to think that determinism is true, branching will not help, and that the issue of branching versus linear time is then actually neutral with respect to the question whether determinism or indeterminism is true. (shrink)

In this paper, I will defend modalfictionalism. The paper has two parts. In thefirst part, I will suggest a revised version ofmodal fictionalism which can avoid certaintechnical problems. In the second part, I willpropose a nominalized version of modalfictionalism and a general scheme offictionalism for the nominalist.

Open future is incompatible with realism about possible worlds. Since realistically conceived (concrete or abstract) possible worlds are maximal in the sense that they contain/represent the full history of a possible spacetime, past and future included, if such a world is actual now, the future is fully settled now, which rules out openness. The kind of metaphysical indeterminacy required for open future is incompatible with the kind of maximality which is built into the concept of possible worlds. The paper discusses (...) various modal realist responses and argues that they provide ersatz openness only, or they lead to incoherence, or they render the resulting theory inadequate as a theory of modality. The paper also considers various accounts of the open future, including rejection of bivalence, supervaluationism, and the ‘thin red line’ view (TRL), and claims that a version of (TRL) can avoid the incompatibility problem, but only at the cost of deflating the notion of openness. (shrink)

There is a widespread assumption that B-theorists (according to whom there is nothing metaphysically special about the present moment in virtue of which it is present) should interpret the standard tense operators (‘it was the case that’, ‘it will be the case that’) as implicit quantifier-restrictors – so that, for example, an utterance at instant t of the sentence ‘It was the case that there are dinosaurs’ is true just in case there are dinosaurs located at some instant t* earlier (...) than t. However, it is easy to show that this interpretation of the tense operators creates serious problems for B-theorists when combined with certain other relatively uncontroversial B-theoretic assumptions. In this paper, I argue that the best way for B-theorists to respond to these problems is to treat the standard tense operators as redundant when the sentences in their scope are qualitative (i.e. not about any particular individuals). (shrink)

This paper discusses “inclusionism” in the context of David Lewis’s modal realism (and in the context of parasitic accounts of modality such as John Divers’s agnosticism about possible worlds). This is the doctrine that everything is a world. I argue that this doctrine would be beneficial to Divers-style agnosticism; that it suggests a reconfiguration of the concept of actuality in modal realism; and finally that it suffers from an as-yet unsolved difficulty, the problem of the unmarried husbands. This problem also (...) shows that Stephen Yablo’s analysis of “intrinsic” is inadequate. (shrink)

I argue that modal realism is unable to account for fictional discourse. My starting point is an overview of modal realism. I then present a dilemma for modal realism regarding fictional characters. Finally, I provide responses to both horns of the dilemma, one motivating modal dimensionalism, the other motivating a disjunctive analysis of modality.

David Lewis's book 'On the Plurality of Worlds' mounts an extended defense of the thesis of modal realism, that the world we inhabit the entire cosmos of which we are a part is but one of a vast plurality of worlds, or cosmoi, all causally and spatiotemporally isolated from one another. The purpose of this article is to provide an accessible summary of the main positions and arguments in Lewis's book.

The question as to whether some objects are possible worlds that have an initial segment in common, i.e. so that their fusion is a temporal tree whose branches are possible worlds, arises both for those who hold that our universe has the structure of a temporal tree and for those who hold that what there is includes concrete universes of every possible variety. The notion of “possible world” employed in the question is seen to be the notion of an object (...) of a kind such that objects of that kind play a certain theoretical role. Lewis’s discussion of the question is thereby clarified but is nevertheless inadequate; his negative answer is correct but even from his combinatorialist viewpoint the rationale he provides for this answer is misguided. I explain why the combinatorialist advocate of concrete plenitude should hold that no object is a tree of possible worlds. Then I explain that for a different reason the nomic essentialist advocate of concrete plenitude should hold this much too. (shrink)

Consider the things that exist—the entities—and let us suppose they are mereologically structured, that is, some are parts of others. The project of ontology within the bounds of bare mereology use this structure to say which of these entities belong to various ontological kinds, such as properties and particulars. My purpose in this paper is to defend the most radical section of the project, the mereological theory of the exemplification of universals. Along the way I help myself to several hypotheses: (...) the existence of merely possible worlds; that particulars have thisnesses; and that mereology is far from classical. Moreover, the way I characterize instantiation might be judged too complicated to be plausible. At the end of the paper, I reply to these objections based on complexity. (shrink)