Possible Worlds, Misc

This paper establishes that the occasional identity relation and the contingent identity relation are both non-transitive and as such are not properly classified as identity relations. This is achieved by appealing to cases where multiple fissions and fusions occur simultaneously. These cases show that the contingent and occasional identity relations do not even satisfy the time-indexed and world-indexed versions of the transitivity requirement and hence are non-transitive relations.

Leibniz has enjoyed a prominent place in the history of thought about possible worlds.' I shall argue that on the feading interpretation of Leibniz's account of contingency — an ingenious interpretation with ample textual support — possible worlds may be invoked by Leibniz only on pain of inconsistency. Leibnizian contingency, as reconstructed in detail by Robert C. Sleigh, Jr.,z will be shown to preclude propositions with different truth-values in different possible worlds.

In Naming and Necessity Kripke argued against the possible existence of fictional characters. I show that his argument is invalid, analyze the confusion it involves, and explain why the view that fictional characters could not have existed is implausible.

How do ordinary objects persist through time and across possible worlds ? How do they manage to have their temporal and modal properties ? These are the questions adressed in this book which is a "guided tour of theories of persistence". The book is divided in two parts. In the first, the two traditional accounts of persistence through time (endurantism and perdurantism) are combined with presentism and eternalism to yield four different views, and their variants. The resulting views are then (...) examined in turn, in order to see which combinations are appealing and which are not. It is argued that the 'worm view' variant of eternalist perdurantism is superior to the other alternatives. In the second part of the book, the same strategy is applied to the combinations of views about persistence across possible worlds (trans-world identity, counterpart theory, modal perdurants) and views about the nature of worlds, mainly modal realism and abstractionism. Not only all the traditional and well-known views, but also some more original ones, are examined and their pros and cons are carefully weighted. Here again, it is argued that perdurance seems to be the best strategy available. (shrink)

David Lewis' modal counterpart theory falls prey to the famous Saul Kripke's objection, and this is mostly due to his 'static' ontology (divergence) of possible worlds. This paper examines a genuinely realist but different, branching ontology of possible worlds and a new definition of the counterpart relation, which attempts to provide us with a better account of de re modality, and to meet satisfactorily Kripke's claim, while being also ontologically more 'parsimonious'.

I outline a neo-Fregean strategy in the debate on the existence of possible worlds. The criterion of identity and the criterion of application are formulated. Special attention is paid to the fact that speakers do not possess proper names for worlds. A broadly Quinean solution is proposed in response to this difficulty.

Accounts of propositions as sets of possible worlds have been criticized for conflating distinct impossible propositions. In response to this problem, some have proposed to introduce impossible worlds to represent distinct impossibilities, endorsing the thesis that impossible worlds must be of the same kind; this has been called the parity thesis. I show that this thesis faces problems, and propose a hybrid account which rejects it: possible worlds are taken as concrete Lewisian worlds, and impossibilities are represented as set-theoretic constructions (...) out of them. This hybrid account (1) distinguishes many intuitively distinct impossible propositions; (2) identifies impossible propositions with extensional constructions; (3) avoids resorting to primitive modality, at least so far as Lewisian modal realism does. (shrink)

Frank Knight (1921) famously distinguished the epistemic modes of certainty, risk, and uncertainty in order to characterize situations where deterministic, probabilistic or possibilistic foreknowledge is available. Because our probabilistic knowledge is limited, i.e. because many systems, e.g. the global climate, cannot be described and predicted probabilistically in a reliable way, Knight's third category, possibilistic foreknowledge, is not simply swept by the probabilistic mode. This raises the question how to justify possibilistic predictionsincluding the identication of the worst case. The development of (...) such a modal methodology is particularly vital with respect to predictions of climate change. I show that a methodological dilemma emerges when possibilistic predictions are framed in traditional terms and argue that a more nuanced conceptual framework, distinguishing dierent types of possibility, should be used in order to convey our uncertain knowledge about the future. The new conceptual scheme, however, questions the applicability of standard rules of rational decision-making, thus generating new challenges. (shrink)

Which mathematical structures are possible, that is, instantiated by the concrete inhabitants of some possible world? Are there worlds with four-dimensional space? With infinite-dimensional space? Whence comes our knowledge of the possibility of structures? In this paper, I develop and defend a principle of plenitude according to which any mathematically natural generalization of possible structure is itself possible. I motivate the principle pragmatically by way of the role that logical possibility plays in our inquiry into the world.

The authors provide an object-theoretic analysis of two paradoxes in the theory of possible worlds and propositions stemming from Russell and Kaplan. After laying out the paradoxes, the authors provide a brief overview of object theory and point out how syntactic restrictions that prevent object-theoretic versions of the classical paradoxes are justified philosophically. The authors then trace the origins of the Russell paradox to a problematic application of set theory in the definition of worlds. Next the authors show that an (...) object-theoretic analysis of the Kaplan paradox reveals that there is no genuine paradox at all, as the central premise of the paradox is simply a logical falsehood and hence can be rejected on the strongest possible grounds—not only in object theory but for the very framework of propositional modal logic in which Kaplan frames his argument. The authors close by fending off a possible objection that object theory avoids the Russell paradox only by refusing to incorporate set theory and, hence, that the object-theoretic solution is only a consequence of the theory’s weakness. (shrink)

This dissertation addresses the problem of trans-world identity in possible worlds semantics, and argues that essentialism does not provide a satisfactory solution to it. If one takes possible worlds semantics seriously as a viable elucidation of the logic of the metaphysical modalities, one must also take a realistic stance toward possible worlds. But then, contrary to Kripke, Plantinga, Van Inwagen, and others, there is a problem with trans-world identity; the real problem being, not the problem of identifying individuals across possible (...) worlds, but rather the problem of the theoretical basis for these identifications. Possible worlds semantics presupposes a substantive theory of what constitutes the cross-world continuation or persistence of individuals. Standard formulations of these semantics nevertheless fail to articulate such a theory. Therefore cross-world identifications become inherently problematic. All available solutions to this problem either presuppose non-trivial essentialism or are incoherent. Non-trivial essentialism is the view that there are certain non-identity properties which a given individual has in every world in which it exists but which other possible individuals fail to have in some of the worlds in which they exist. ;But the question of the coherence of essentialism itself is intimately connected with one's views concerning the nature and existence of properties. Three Cantorian paradoxes are adduced, one against individuative essentialism, one against non-trivial essentialism, and one against properties in general. The paradoxes against properties in general and non-trivial essentialism can be avoided only if one eschews a Quine/Goodman view of property existence---the view that any extensionally well-defined class answers to a property---and makes some kind of distinction between natural and artificial properties. Nevertheless such an eschewal does not avoid the paradox of individuative essentialism. Thus essentialism cannot provide a completely adequate theory of trans-world individuation. For although it provides the necessary conditions for the identity of individuals across possible worlds, it does not allow us to identify these individuals on this basis alone. This conclusion precludes actualist solutions to the problem of the individuation of possibilia which quantify over individual essences. (shrink)

There are many ways the world might be, for all I know. For all I know, it might be that there is life on Jupiter, and it might be that there is not. It might be that Australia will win the next Ashes series, and it might be that they will not. It might be that my great-grandfather was my great-grandmother's second cousin, and it might be that he was not. It might be that copper is a compound, and it (...) might be that it is not. (shrink)

A common argument for atheism runs as follows: God would not create a world worse than other worlds he could have created instead. However, if God exists, he could have created a better world than this one. Therefore, God does not exist. In this paper I challenge the second premise of this argument. I argue that if God exists, our world will continue without end, with God continuing to create value-bearers, and sustaining and perfecting the value-bearers he has already created. (...) Given this, if God exists, our world—considered on the whole—is infinitely valuable. I further contend that this theistic picture makes our world's value unsurpassable. In support of this contention, I consider proposals for how infinitely valuable worlds might be improved upon, focusing on two main ways—adding value-bearers and increasing the value in present value-bearers. I argue that neither of these can improve our world. Depending on how each method is understood, either it would not improve our world, or our world is unsurpassable with respect to it. I conclude by considering the implications of my argument for the problem of evil more generally conceived. (shrink)

En su ópera prima, antes de concebir la filosofía crítica, Kant manifestó su entusiasmo por una geometría de todos los tipos posibles de espacio, y no sólo del espacio conocido. Como el filósofo atribuye cada espacio a un mundo posible distinto, la "geometría suprema", como la denominó, en realidad sería el nombre genérico para un conjunto de geometrías diversas que describen espacios igualmente diversos. En ese conjunto genérico se encuentra la geometría de Euclides, y cabe preguntarse si acaso entre las (...) otras especies no podrían hallarse las geometrías que hoy conocemos como no-euclídeas. Creemos que no es así, y es lo que nos proponemos mostrar en este trabajo. Sostendremos, por lo tanto, la distinción entre las denominaciones "otras geometrías" y "geometrías no-euclídeas" y desarrollaremos la incompatibilidad entre ambas tal como ésta se sigue de los textos de Kant. Intentaremos asimismo caracterizar las "otras geometrías" según la noción de "espacio habitado", por nosotros o por los eventuales habitantes de otros universos posibles. Así, las "otras geometrías" quizá podrían ser comprendidas mejor como geometrías de los otros (de la alteridad), que como anticipación de las geometrías no-euclídeas. (shrink)

It is commonly assumed that all propositions have modal profiles and therefore bear their truth-values either contingently or necessarily. I argue against this commonly assumed view and in defence of amodalism, according to which certain true propositions are neither necessarily nor contingently true, but only true simpliciter. I consider three arguments against ‘possible-worlds theories’, which hold that modal concepts are to be analysed in terms of possible worlds. Although each of these arguments targets a different version of possible-worlds theory, these (...) versions jointly exhaust the entire range of possible-worlds theories. After showing that each argument is naturally addressed by adopting amodalism, I argue that all defenders of possible-worlds theory ought to accept amodalism. (shrink)

Formalized physical theories are not, as a rule, stated in intensional languages. Yet in talking about them we often treat them as if they were. We say for instance: 'Consider what would happen if instead of p's being true q were. In such a case r would be likely.' If we say this sort of thing, p, q and r appear to stand for the meanings of sentences of the theory, but meanings in some intensional sense. Now it is very (...) easy to extend the syntax of the formal theory by adding all sorts of intensional operators, e.g. a modal operator; and it is possible to extend the semantics by adding a set of possible worlds and evaluating the modal formulae in the usual way. But this procedure is open to the criticism that we are extending the theory by adding something which is not already there. In particular the criticism will be that the possible worlds required by the semantics seem to have no connection with the intended interpretations of the original physical theory. The aim of this paper is to shew how a set of possible worlds is already implicit in the intended interpretations of a formally presented physical theory and that these interpretations induce, in a comparatively direct way, an intensional semantics which corresponds to the original one. (shrink)

There are ways in which the new tenseless theory of time is analogous to David Lewis’s modal realism. The new tenseless theory gives an indexical analysis of temporal terms such as ‘now’, while Lewis gives and indexical analysis of ‘actual’. For the new tenseless theory, all times are equally real; for Lewis, all worlds are equally real. In this paper I investigate this apparent analogy between these two theories, and ask whether a proponent of one is committed, by parity of (...) reasoning, to the other. I conclude that the analogy is merely apparent, and that independent reasons are needed to support each theory. (shrink)

In this paper, we give a precise characterization of the principle of recombination and argue that it need not be subject to any restrictions.

Ziel dieses systematischen Ansatz ist es eine Antwort auf die Frage der Wahrheitswertzuschreibung für irreale Konditionalsätze zu geben. Die große philosophische Fragestellung, die damit verfolgt wird, betrifft das Verhältnis von Sprache und Welt, Wirklichkeit und Möglichkeit. Am Ende wird geklärt inwiefern logische Strukturen einen Weltbezug haben. Damit ist ein Vorschlag der Naturalisierung der Normativität der Semantik verbunden. Außer sprachphilosophischen Überlegungen werden auch erkenntnistheoretische und wissenschaftstheoretische Überlegungen angestellt. -/- Inhaltsverzeichnis -/- Vorwort 7 -/- Einführung 8 -/- I. Tatsachen I -/- 1. (...) Unabhängigkeit von Tatsachen und Variationen des Gegebenen 37 1.1 Was wäre, wenn Tatsachen nicht unabhängig voneinander wären? 40 1.2 Folgen für Überlegungen zu Variationen des Gegebenen, wenn Tatsachen nicht unabhängig voneinander wären 41 1.3 Das Prinzip der Ununterscheidbarkeit 43 1.4 Modale Kontexte und referentielle Undurchlässigkeit 46 1.5 Wahrheitswertsemantik und wesentliche Eigenschaften 49 1.6 Das modale Argument 51 1.7 Eine einzige Tatsache 51 1.8 Situationssemantik 55 1.9 Unabhängigkeit von Tatsachen II 61 1.10 Referentielle und attributive Lesart 63 -/- Probleme mit Tatsachen als Wahrmachern; kontingente und notwendige oder wesentliche Eigenschaften; attributive und referentielle Lesart; Tatsachen als Voraussetzung -/- II. Notwendigkeit -/- 2. Das Notwendige bestimmt das Mögliche I 68 -/- Der Notwendigkeitscharakter des Apriorischen; Kant und Kripke; Identität und Notwendigkeit; Identität und kontrafaktische Sätze; Identität und materieller Ursprung; theoretische Identifikation und natürliche Arten; wesentliche Eigenschaften und notwendige Identifikation; absolute Identität -/- 3. Das Notwendige bestimmt das Mögliche II 84 3.1 Der Notwendigkeitscharakter des Apriorischen oder der Aprioritätscharakter des Möglichen. Induktionsprobleme 86 3.2 Der Möglichkeitsbegriff im "Tractatus" 92 -/- Die Rolle des Apriori für die Begriffe Möglichkeit und Notwendigkeit; Möglichkeit und Notwendigkeit in der Logik; der Möglichkeitsbegriff im Tractatus; Kritik von Seiten des Intuitionismus -/- 4. Das Notwendige bestimmt das Mögliche III 97 -/- Die Bedeutung von Quines Kritik an der Unterscheidung von analytisch und synthetisch für den Notwendigkeitsbegriff; Kritik an dieser Kritik und an "Es könnte auch anders sein" als Ausdruck jedweder Unmöglichkeit von Notwendigkeit. Verhältnis zwischen logischen Gesetzen und Erfahrung -/- III. Projektion und Regelfolgen -/- 5. Ein Verständnis von Möglichkeit und Projektion ohne den Begriff der Notwendigkeit. Der Möglichkeitsbegriff in den "Bemerkungen zu den Grundlagen der Mathematik" von Ludwig Wittgenstein 109 -/- Mathematisches Apriori und Möglichkeit; Möglichkeit ohne mathematisches Apriori; das Verhältnis von Möglichkeit und Neuem oder Anderem; Erfahrung und Möglichkeit, Möglichkeit und Symbol; Möglichkeit und Normativität; Projektion von Symbolen -/- 6. Ähnlichkeit und Projektion - Projektion und Regelfolgen 120 -/- Möglichkeit als Bereich der Induktion oder des Regelfolgens. Parallelen zwischen Kripkes Skepsis in bezug auf Regelfolgen und Goodmans Fassung des Induktionsproblems. Tatsache und Wirklichkeit. Identität und Ähnlichkeit; Möglichkeit als enge Relation zur Wirklichkeit; die Reduktion von Möglichem auf Wirkliches bei Goodman; Erfahrung und Kriterien der Identität; Regeln als Praxis und ihr normativer Gehalt; tatsächliche Fortsetzbarkeit und Normativität -/- IV. Tatsachen II -/- 7. Tatsachen und Welterzeuger I 134 -/- Der Tatsachenbegriff Goodmans; Tatsachen, denen kein realistischer Wahrheitsbegriff zugrunde liegt; richtige und falsche Weltversionen; die Versöhnung von Weltversionen; relevante Merkmale und Tatsachen; Tatsachen erzeugen Wirklichkeiten, erzeugte Weltversionen und Tatsachenbegriff -/- V. Wirklichkeit -/- 8. Wirklichkeit und Möglichkeit 147 -/- Wirklichkeit von Dingen, Erzählungen und Empfindungen; Historizität ist nicht gleich Relativität; Goodmans mathematische Beispiele zum Verhältnis zwischen Wirklichkeit, Wahrheit und Welt; Mathematik und Erfahrung; Verankerung, Abgeschlossenheit und Unabgeschlossenheit von Wirklichkeit und Möglichkeit -/- 9. Unendlichkeit und Wirklichkeit 157 -/- Das Unendliche ist größer als die Wirklichkeit; Unendlichkeit und Situationssemantik; Unendlichkeit und Fortsetzbarkeit; Definition der minimalen Situation; Verhältnis zwischen aktualer Unendlichkeit und Wirklichkeit, von Wirklichkeit und Tatsache und von Möglichkeit und Unendlichkeit; Definition von echter aktualer Unendlichkeit und "praktischer" Unendlichkeit mit Hilfe des Begriffs der Linearität -/- VI. Tatsachen III -/- 10. Tatsachen und Welterzeuger II 172 10.1 Wissen und Erfahrung 181 10.2 Wissen und Tatsachen 183 10.3 Zweifel an der Existenz der Welt 184 10.4 Feststehende und nicht feststehende Sätze 186 10.5 Interner Realismus und interner Interpretationismus 189 10.6 Der Tatsachenbegriff in "Über Gewißheit" 191 -/- Tatsachen und Interpretationsphilosophie; skeptische Positionen und Tatsachen; logische Vorgängigkeit unter den Interpretationsebenen?; transzendentale Argumentationen und Notwendigkeit von Begriffsystemen; der logische Stellenwert von Tatsachenfeststellungen -/- 11. Tatsachen und Situationen 197 -/- Tatsachen als Individuen; Tatsachen als wahre Propositionen; Tatsachen als minimale Situationen; Tatsachen und Unendlichkeit; Tatsachen und Projektion; Tatsachen und Regelfolgen -/- VII. Relationen -/- 12. Interne und externe Relationen. Was kann der Begriff der internen Relation leisten? 209 -/- Interne und externe Relationen; Parallelen bei der Unterscheidung von externen und internen Relationen zu den Unterscheidungen von Logik und Naturgeschichte, synthetischen Sätzen a priori und Erfahrung und Regelsätzen und Erfahrung -/- 13. Kontingente Tatsachen und gültiges Urteilen. 224 -/- Kratzers Klumpungsrelation (Lumps of Thought) als Enthaltenseinsrelation und G. E. Moores materiale Implikation; zurück zu den Smaragden Goodmans; das Hinzuziehen allgemeiner, verankerter Grundsätze, deren Verankerung nicht auf reiner Gewohnheit beruht -/- 14. Relationen und kontrafaktisches Schließen 239 -/- Nackte Einzeldinge und Universalien sowie ihre modalen Grundlagen; Relationen als Leitfaden für Urteile, zurück zu internen und externen Relationen; der durch Naturgeschichte übermittelte Maßstab der Sprache -/- VIII. Naturgeschichte -/- 15. Naturgeschichte 254 -/- Naturgeschichte als feststehender Hintergrund für kontingente Sprache und gültiges Urteilen; die Begründung von Normativität in Naturgeschichte; Naturgeschichte als Apriori -/- 16. Sprache und Naturgeschichte. Ein Resümee 266 -/- Appendix: Weltrealisten hinsichtlich möglicher Welten 273 -/- Literaturverzeichnis 279. (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)

A new puzzle of modal recombination is presented which relies purely on resources of first-order modal logic. It shows that naive recombinatorial reasoning, which has previously been shown to be inconsistent with various assumptions concerning propositions, sets and classes, leads to inconsistency by itself. The context sensitivity of modal expressions is suggested as the source of the puzzle, and it is argued that it gives us reason to reconsider the assumption that the notion of metaphysical necessity is in good standing.

The modal properties of the principle of the causal closure of the physical have traditionally been said to prevent anything outside the physical world from affecting the physical universe and vice versa. This idea has been shown to be relative to the definition of the principle (Gamper 2017). A traditional definition prevents the one universe from affecting any other universe, but with a modified definition, e.g. (ibid.), the causal closure of the physical can be consistent with the possibility of one (...) universe affecting the other universe. Gamper (2017) proved this modal property by implementing interfaces between universes. Interfaces are thus possible, but are they realistic? To answer this question, I propose a two-step process where the second step is scientific research. The first step, however, is to fill the gap between the principles or basic assumptions and science with a consistent theoretical framework that accommodates the modal properties of an ontology that matches the basic assumptions. (shrink)

Ever since Saul Kripke and others developed a semantic interpretation for modal logic, 'possible worlds' has been a much debated issue in contemporary metaphysics. To propose the idea of a possible world that differs in some way from our actual world - for example a world where the grass is red or where no people exist - can help us to analyse and understand a wide range of philosophical concepts, such as counterfactuals, properties, modality, and of course, the notions of (...) possibility and necessity. This book examines the ways in which possible worlds have been used as a framework for considering problems in logic and argument analysis. The book begins with a non-technical introduction to the basic ideas of modal logic in terms of Kripke's possible worlds and then moves on to a discussion of 'possible for' and 'possible that'. The central chapters examine questions of meaning, epistemic possibility, temporal logic, metaphysics, and impossibility. Girle also investigates how the idea of a possible world can be put to use in different areas of philosophy, the problems it may raise, and the benefits that can be gained. (shrink)

Various writers have proposed that the notion of a possible world is a functional concept, yet very little has been done to develop that proposal. This paper explores a particular functionalist account of possible worlds, according to which pluralities of possible worlds are the bases for structures which provide occupants for the roles which analyse our ordinary modal concepts. It argues that the resulting position meets some of the stringent constraints which philosophers have placed upon accounts of possible worlds, while (...) also trivializing the question what possible worlds are. The paper then discusses a range of problems facing the functionalist position. (shrink)

There are numerous contexts in which philosophers and others use model-theoretic methods in assessing the validity of ordinary arguments; consider, for example, the use of models built upon 'possible worlds' in examinations of modal arguments. But the relevant uses of model-theoretic techniques may seem to assume controversial semantic or metaphysical accounts of ordinary concepts. So, numerous philosophers have suggested that standard uses of model-theoretic methods in assessing the validity of modal arguments commit one to accepting that modal claims are to (...) be analysed in terms of possible worlds. The paper provides a very general account of how uses of model-theoretic methods in demonstrating facts about validity and invalidity may in fact often be uncoupled from controversial semantic or metaphysical theses, applying the resulting techniques to some modal cases in particular. (shrink)

This chapter is concerned with the coextension difficulty for nominalist theories of properties that reject tropes alongside universals. After carefully explaining the coextension difficulty and describing the theories it targets, the chapter describes different solutions to the difficulty. These solutions differ with respect to how much involved they are into a dualist approach to coextension. A dualist approach to a case of coextension consists in agreeing with the realist that the relevant ascriptions of properties are numerically distinct. A monist approach (...) to a case of coextension consists in contending that the relevant ascriptions of properties are identical. In this chapter, I defend a monist approach to cases of coextension that appeals to a counterpart theory for propositions. (shrink)

According to possibilism, or non-actualism, fictional characters are possible individuals. Possibilist accounts of fiction do not only assign the intuitively correct truth-conditions to sentences in a fiction, but has the potential to provide powerful explanatory models for a wide range of phenomena associated with fiction (though these two aspects of possibilism are, I argue, crucially distinct). Apart from the classic defense by David Lewis the idea of modeling fiction in terms of possible worlds have been widely criticized. In this article, (...) I provide a defense of a possibilist account against some lines of criticism. To do so, I assume that names for fictional characters are directly referential and a possible-worlds model that accommodates transworld identity. On this background, I argue, it is possible to construct an elegant model of fictional discourse using familiar models of information exchange in ordinary discourse, and I sketch how this model can be used to i) make a natural distinction between fictional and counterfactual discourse, ii) account for creativity, and iii) sustain a natural definition of truth-in-fiction that avoids certain familiar objections to possibilism. Though I set aside questions about the metaphysical commitments of a possible-world interpretation here, there is accordingly reason to think that the battle over possibilist treatments of fiction will have to be fought over metaphysical foundations rather than technical shortcomings. (shrink)

In a pair of recent essays, William Lane Craig has argued that certain open theist understandings of the nature of the future are both semantically and modally confused. I argue that this is not the case and show that, if consistently observed, the customary semantics for counterfactuals Craig relies on not only undermine the validity of his complaint against the open theist, they actually support an argument for the openness position.

Metaphysical nihilism is the thesis that there could have been no concrete objects. Thomas Baldwin (1996) offers an argument for metaphysical nihilism. The premisses of the argument purport to provide a procedure of subtraction that can be iterated until we reach a world where no concrete objects exist. Gonzalo Rodriguez-Pereyra (1997) finds fault with Baldwin’s argument, modifies it, and claims to have proved metaphysical nihilism. My primary aim is to show that Rodriguez-Pereyra’s alleged proof rests on a false assumption. The (...) assumption is that, necessarily, if there are no concrete* objects (in the sense Rodriguez-Pereyra defines), then there are no concrete objects. My secondary aim, with which I begin, is to formulate and then strengthen a succinct version of the subtraction argument. (shrink)

My dissertation consists of three essays in the Metaphysics of Modality: In "A Puzzle about Truth and Singular Propositions," I consider two theses that seem to be true and then an argument for the conclusion that they form an inconsistent pair. One thesis is that a proposition that is singular with respect to a given object implies that the object exists. This is so because the proposition predicates something of the object. The other thesis is that some propositions are true (...) with respect to possible worlds in which they do not exist. An example is the negation of the proposition that Socrates is wise. This proposition is true with respect to possible worlds in which Socrates does not exist, but it does not exist in those worlds. ;In "Actualism, Ontological Dependence, and Possible Worlds," I consider Actualism, the doctrine that every possible object is an actual object. Plantinga has argued that the actualist is committed to the existence of unexemplified essences if he analyzes statements of modality by quantifying over possible worlds and over members of their domains. I argue that the actualist is committed to the existence of unexemplified essences even if he paraphrases statements of modality by quantifying only over possible worlds and actual objects. ;In "Possibilism and the Nature of Actuality," I consider Possibilism, the doctrine that there are possible objects that are not actual objects. Possibilism seems to be a coherent ontological doctrine. It is not Meinong's doctrine that there are objects of which it is true to say that there are no such objects. If one fails to distinguish between these two doctrines, then one's attempt to refute Possibilism might amount to an attack on a blatant contradiction. I illustrate this claim by arguing that the distinction between Possibilism and Meinong's doctrine has eluded Plantinga. I then consider the view that Possibilism is a consequence of Lewis's doctrine that 'actual' is an indexical term. I also argue that the sense in which Lewis said that 'actual' is indexical is an esoteric sense of the word, not a sense it ordinarily has. (shrink)

This paper makes a point about the interpretation of the simplest quantified modal logic, that is, quantified modal logic with a single domain. It is commonly assumed that the domain in question is to be understood as the set of all possibile objects. The point of the paper is that this assumption is misguided.

The thesis that entities exist in, at, or in relation to logically possible worlds is criticized. The suggestion that actually nonexistent fictional characters might nevertheless exist in nonactual merely logically possible worlds runs afoul of the most general transworld identity requirements. An influential philosophical argument for the concept of world-relativized existence is examined in Alvin Plantinga’s formal development and explanation of modal semantic relations. Despite proposing an attractive unified semantics of alethic modality, Plantinga’s argument is rejected on formal grounds as (...) supporting materially false actual existence assertions in the case of actually nonexistent objects in the framework of Plantinga’s own underlying classical predicate-quantificational logic. (shrink)

Possibility offers a new analysis of the metaphysical concepts of possibility and necessity, one that does not rely on any sort of "possible worlds." The analysis proceeds from an account of the notion of a physical object and from the positing of properties and relations. It is motivated by considerations about how we actually speak of and think of objects. Michael Jubien discusses several closely related topics, including different purported varieties of possible worlds, the doctrine of "essentialism," natural kind terms (...) and alleged examples of necessity a posteriori. The book also offers a new theory of the functioning of proper names, both actual and fictional, and the discussion of natural kind terms and necessity a posteriori depends in part on this theory. (shrink)

There are two types of theories regarding many worlds: one is modal, while the other is temporal. The former regards reality as consisting of many possible worlds, while the latter holds that reality consists of many momentary worlds, which are usually called moments. I compare these two theories, paying close attention to the concept of transworld identity and compare trans-possible world identity with trans-momentary world identity (or transmoment identity). I characterize time from the point of many-worlds view, believing this to (...) be one of the best ways of grasping the reality of time. First, I show that there is reason to adopt the many-worlds view because transworld identity is meaningful for both of them, while it is not for space. Second, I argue that transmoment identity is different from transpossible world identity concerning reality. The former is a realistic relation, while the latter is not. Thus, I find that the reality of time is in the relation of transmoment identity. Such a view, I contend, has merit on the basis that it recognizes the reality of time in a sense that is not true of space. (shrink)

Review of Bob Hale's "Necessary Beings: An Essay on Ontology, Modality, and the Relations Between Them". Oxford: Oxford University Press 2013, ISBN 9780199669578.

Thomas Aquinas is often mentioned in the debate regarding best possible worlds. Some philosophers believe Aquinas’ writings entail that God must create a best possible world while most think he rejects the notion. Additionally, it is thought that Aquinas’ position falls prey to the problem of no best world. However, a closer examination of Aquinas’ metaphysical views shows that he has been misunderstood in the current debate. In this essay, I first examine some contemporary views regarding Aquinas’ thought on best (...) possible worlds. Afterward, I discuss Aquinas’ concepts of God’s goodness and God’s purpose for creating and determine their implications for his position regarding best possible worlds. Understanding these concepts helps to show why Aquinas’ position has been misrepresented. I conclude that while Aquinas does reject the popular notion of a best possible world, his arguments are not susceptible to the problem of no best world. (shrink)

David Lewis argues that centered worlds give us a way to capture de se, or self-locating, contents in philosophy of language and philosophy of mind. In recent years, centered worlds have also gained other uses in areas ranging widely from metaphysics to ethics. In this paper, I raise a problem for centered worlds and discuss the costs and benefits of different solutions. My investigation into the nature of centered worlds brings out potentially problematic implicit commitments of the theories that employ (...) them. In addition, my investigation shows that the conception of centered worlds widely attributed to David Lewis is not only problematic, but in fact not his. (shrink)

Preface In these days, an anthology on the topic of possible worlds hardly needs justification. No issue has given rise to as much literature in the past ...

We offer a number of arguments for or against particular metaphysical theses. All of them are based in phenomena or results in mathematical logic, broadly conceived, and are offered as exemplification of the possibility of arguing in metaphysics from such results.