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)

This appeared in Philosophy and Phenomenological Research 59:473-93, as a response to four papers in a symposium on my book The Conscious Mind . Most of it should be comprehensible without having read the papers in question. This paper is for an audience of philosophers and so is relatively technical. It will probably also help to have read some of the book. The papers I’m responding to are: Chris Hill & Brian McLaughlin, There are fewer things in reality than are (...) dreamt of in Chalmers’ philosophy Brian Loar, David Chalmers’ The Conscious Mind Sydney Shoemaker, On David Chalmers’ The Conscious Mind Stephen Yablo, Concepts and consciousness Contents. (shrink)

Perhaps no one has done more in the last 30 years to advance thinking in the metaphysics of modality than has Alvin Plantinga. Collected here are some of his most important essays on this influential subject. Dating back from the late 1960's to the present, they chronicle the development of Plantinga's thoughts about some of the most fundamental issues in metaphysics: what is the nature of abstract objects like possible worlds, properties, propositions, and such phenomena? Are there (...) possible but non-actual objects? Can objects that do not exist exemplify properties? Plantinga gives thorough and penetrating to all of these questions and many others. This volume contains some of the best work in metaphysics from the past 30 years, and will remain a source of critical contention and keen interest among philosophers of metaphysics and philosophical logic for years to come. (shrink)

These essays, dating from the late 1960's to the present, chronicle the development of Plantinga's thoughts about some of the most fundamental issues in metaphysics: what is the nature of abstract objects like possible worlds, properties, propositions, and such phenomena? Are there possible but non-actual objects? Can objects that do not exist exemplify properties? Plantinga gives thorough and penetrating answers to these and other questions.

In the past three decades there has been a rapid development of the formal machinery for modal logic. Quantified modal logic has developed along with a semantics and model theory that is appropriate to it. With this technical development there has been relatively little discussion of what modality is all about. There are two fundamental questions that have gone unanswered. First, to what does necessity amount? Is this a new logical notion, or is it something that can be further (...) analyzed in terms of other notions that we already have at our disposal? The second question is what makes truths involving necessity true? What is their ontological grounding in the world? This essay is directed at the first of these questions. ;There are three possible reductions of metaphysical modality. First, there is the reduction suggested by the semantics for modal logic: a reduction in terms of possible worlds. Second, there is the reduction in terms of cognition. What is possible is what is conceivable. Third, there is the reduction in terms of language. Necessities arise from the structures of language and/or language use. ;I argue that none of these is successful. All of them suffer either from presupposing some form of metaphysical necessity in the reductive base, rendering them circular and not truly reductive, or they do not do justice to the modality being reduced. ;Since necessity is not reducible to any non-modal features of the world, we need to determine whether we ought to reject it as unacceptable on this basis, or whether we ought to retain it, but treat is as a new primitive that is introduced into a philosophical or logical theory. I urge the latter course is the one that we ought to take because without it too many things will likewise be deemed unacceptable. Causal necessity and explanation, normally accepted theories or knowledge and perception, logic and logical validity, and one common manner of distinguishing sets from properties will be deemed unacceptable if de re necessity is unacceptable. All of these presuppose de re metaphysical necessity in some way. I conclude that de re metaphysical necessity ought to be retained in our theory as primitive, unanalyzable notion. (shrink)

This volume contains some of the best work in metaphysics from the past 30 years, and will remain a source of critical contention and keen interest among ...

Brian Leftow sets out to provide us with an account of Aquinas’s metaphysics of modality. Drawing on some important recent work, which is surely close to the spirit (if not quite the letter) of Aquinas’s thought, he frames his discussion in terms of “truthmakers”: what is it that makes true claims about possibility and necessity—that is to say, what serves as their ontological ground or ultimate metaphysical explanation? Leftow’s main thesis is that, for Aquinas, all true modal claims (...) are made true by one and the same thing—namely, God. Along the way, however, he also attempts to show that Aquinas’s endorsement of this thesis commits him to an objectionable form of Platonism about possible worlds. (shrink)

In this paper I explore modal metaphysics in regard to Francisco Suárez’s idea of real being, in order to track down an early model of the relationship between synchronical alternative states of affairs and the temporal frequency paradigm. In doing so this article will offer an interpretation of Suárez’s doctrine of eternal truths as found in Disputationes Metaphysicae d. 31, c. 12, § 38–§ 47. I argue that Suárez’s modal theory of real possibilities and logical possibilities should be regarded (...) as an actualist and essentialist form of modalism. (shrink)

Considering the importance of possible-world semantics for modal logic and for current debates in the philosophy of modality, a phenomenologist may want to ask whether it makes sense to speak of “possible worlds” in phenomenology. The answer will depend on how "possible worlds" are to be interpreted. As that latter question is the subject of the debate about possibilism and actualism in contemporary modal metaphysics, my aim in this paper is to get a better grip on the former (...) question by exploring a Husserlian stance towards this debate. I will argue that the phenomenologist’s way to deal with the problem of intentional reference to mere possibilia is analogous to the actualist’s idea of how “possible worlds” are to be interpreted. Nevertheless, I will be pointing to a decisive difference in the metaphilosophical preconditions of what I call "phenomenological actualism" and analytical versions of actualism. (shrink)

James Ladyman ([2000]) argues that constructive empiricism is untenable because it cannot adequately account for modal statements about observability. In this paper, I attempt to resist Ladyman's conclusion, arguing that the constructive empiricist can grant his modal discourse objective, theory-independent truth-conditions, yet without compromising his empiricism.

A Critical Introduction to the Metaphysics of Modality examines the eight main contemporary theories of possibility behind a central metaphysical topic. Covering modal skepticism, modal expressivism, modalism, modal realism, ersatzism, modal fictionalism, modal agnosticism, and the new modal actualism, this comprehensive introduction to modality places contemporary debates in an historical context. Beginning with a historical overview, Andrea Borghini discusses Parmenides and Zeno; looks at how central Medieval authors such as Aquinas, and Buridan prepared the ground for the (...) Early Modern radical views of Leibniz, Spinoza, and Hume and discusses advancements in semantics in the later-half of the twentieth century a resulted in the rise of modal metaphysics, the branch characterizing the past few decades of philosophical reflection. Framing the debate according to three main perspectives - logical, epistemic, metaphysical- Borghini provides the basic concepts and terms required to discuss modality. With suggestions of further reading and end-of-chapter study questions, A Critical Introduction to the Metaphysics of Modality is an up-to-date resource for students working in contemporary metaphysics seeking a better understanding of this crucial topic. (shrink)

First published in 1999. Routledge is an imprint of Taylor & Francis, an informa company.

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 ...

For the past 30 years, Alvin Plantinga's work in the metaphysics of modality has been both insightful and innovative; it is high time that his papers in this area be collected together in a single volume. This book contains 11 pieces of Plantinga's work in modal metaphysics, arranged in chronological order so one can trace the development of his thought on matters modal. In what follows I will lay out the principal concepts and arguments in these papers.

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)

Constructive empiricism is supposed to offer a positive alternative to scientific realism that dispenses with the need for metaphysics. I first review the terms of the debate before arguing that the standard objections to constructive empiricism are not decisive. I then explain van Fraassen's views on modality and counterfactuals, and argue that, because constructive empiricism recommends on epistemological grounds belief in the empirical adequacy rather than the truth of theories, it requires that there be an objective modal distinction (...) between the observable and the unobservable. This conclusion is incompatible with van Fraassen's empiricism. Finally I explain some further problems for constructive empiricism that arise when we consider modal matters. (shrink)

Constructive empiricism is supposed to offer a positive alternative to scientific realism that dispenses with the need for metaphysics. I first review the terms of the debate before arguing that the standard objections to constructive empiricism are not decisive. I then explain van Fraassen's views on modality and counterfactuals, and argue that, because constructive empiricism recommends on epistemological grounds belief in the empirical adequacy rather than the truth of theories, it requires that there be an objective modal distinction (...) between the observable and the unobservable. This conclusion is incompatible with van Fraassen's empiricism. Finally I explain some further problems for constructive empiricism that arise when we consider modal matters. (shrink)

In this book, Richard Brian Davis explores various attempts to solve the Dependence Problem – the problem posed by the following question: How can necessary truths stand to God in a one-way relation of dependence when neither they nor God could have failed to exist? Critics charge that this problem is insoluble. Davis argues at length that the most powerful and promising contemporary solutions to this problem – those offered by Linda Zagzebski, Brian Leftow, Thomas V. Morris, and William Mann (...) – are all fatally flawed. In making his case, Davis treats the reader to helpful and interesting discussions of counterpossibles, broadly logical necessity, identity statements, as well as the divine attributes of sovereignty, aseity, and simplicity. He concludes with what is perhaps the most forceful and sustained defense of the claim that necessary truths can stand to God in an asymmetrical relation of causal dependence. (shrink)

Two arguments have recently been advanced that Maxwell-Boltzmann particles areindistinguishable just like Bose–Einstein and Fermi–Dirac particles. Bringing modalmetaphysics to bear on these arguments shows that ontological indistinguishabilityfor classical (MB) particles does not follow. The first argument, resting on symmetryin the occupation representation for all three cases, fails since peculiar correlationsexist in the quantum (BE and FD) context as harbingers of ontic indistinguishability,while the indistinguishability of classical particles remains purely epistemic. The secondargument, deriving from the classical limits of quantum statistical partition (...) functions,embodies a conceptual confusion. After clarifying the doctrine of haecceitism, a thirdargument is considered that attempts to deflate metaphysical concerns altogether byshowing that the phase-space and distribution-space representations of MB-statisticshave contrary haecceitistic import. Careful analysis shows this argument to fail as well,leaving de re modality unproblematically grounding particle identity in the classicalcontext while genuine puzzlement about the underlying ontology remains for quantumstatistics. (shrink)

Two arguments have recently been advanced that Maxwell-Boltzmann particles areindistinguishable just like Bose–Einstein and Fermi–Dirac particles. Bringing modalmetaphysics to bear on these arguments shows that ontological indistinguishabilityfor classical (MB) particles does not follow. The first argument, resting on symmetryin the occupation representation for all three cases, fails since peculiar correlationsexist in the quantum (BE and FD) context as harbingers of ontic indistinguishability,while the indistinguishability of classical particles remains purely epistemic. The secondargument, deriving from the classical limits of quantum statistical partition (...) functions,embodies a conceptual confusion. After clarifying the doctrine of haecceitism, a thirdargument is considered that attempts to deflate metaphysical concerns altogether byshowing that the phase-space and distribution-space representations of MB-statisticshave contrary haecceitistic import. Careful analysis shows this argument to fail as well,leaving de re modality unproblematically grounding particle identity in the classicalcontext while genuine puzzlement about the underlying ontology remains for quantumstatistics. (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)

ABSTRACT. Two arguments have recently been advanced that Maxwell-Boltzmann particles are indistinguishable just like Bose-Einstein and Fermi-Dirac particles. Bringing modal metaphysics to bear on these arguments shows that ontological indistinguishability for classical (MB) particles does not follow. The first argument, resting on symmetry in the occupation representation for all three cases, fails since peculiar correlations exist in the quantum (BE and FD) context as harbingers of ontic indistinguishability, while the indistinguishability of classical particles remains purely epistemic. The second argument, (...) deriving from the classical limits of quantum statistical partition functions, embodies a conceptual confusion. After clarifying the doctrine of haecceitism, a third argument is considered that attempts to deflate metaphysical concerns altogether by showing that the phase-space and distribution-space representations of MB-statistics have contrary haecceitistic import. Careful analysis shows this argument to fail as well, leaving de re modality unproblematically grounding particle identity in the classical context while genuine puzzlement about the underlying ontology remains for quantum statistics. (shrink)

The book also sheds new light on the nature of metaphysical theorizing by exploring the interaction of semantic and metaphysical issues, the connections between different metaphysical issues, and the nature of ontological commitment.

“Modal logic was conceived in sin: the sin of confusing use and mention.” So quips Quine. The stigma stuck with modal logic for a while. But by the mid-sixties, a whole cluster of mathematically elegant interpretations of modal logic became available. All are natural extensions of the classical Tarskian semantics of predicate logic. By the mid-seventies, Quine’s criticisms seemed obsolete. Today, we teach the model theory of modal logic as a matter of course. Quine’s “interpretive problem” is just forgotten. The (...) purpose of my dissertation is to revamp Quine’s thesis: the very foundations of modal logic—simple propositional modal logic, even before quantifiers are added—are shaky. Quine holds that the natural interpretation of the operator “necessarily” is in terms of a full-blooded metaphysical notion of real necessity. Such a notion, Quine conjectures, is committed to the “metaphysical jungle of Aristotelian essentialism”. Hence, the intended interpretation is to be rejected. Thus Quine: so much the worse for real necessity. An alternative comes to mind: a meta-level, formal rather than real, semantic interpretation of the operator of necessity. In the late forties, Carnap developed this line of interpretation which culminates in the aforementioned model theory (“Kripke’s possible world semantics”) in the sixties. On this basis a formal interpretation is introduced: it grounds necessity in the notion of model theoretic validity. As pointed by friends of the formal interpretation (Marcus, Parsons and Kaplan), no invidious essentialist claim is verified. But have Quine’s concerns been answered? Yes and no. Technical problems regarding quantification across modal operators, substitutivity, matters of scope, and the basis of cross-world identification have indeed been solved. However, no real interpretation of “necessarily” has been provided. I argue that the seeds of such an interpretation are present in Kripke’s philosophical discussion of de re necessities in Naming and Necessity. It is not model theoretic, and it does not reduce necessity to some non-modal notion, just as Quine predicted. Even more in his vein, the real interpretation is (i) metaphysically, grounded indeed in essentialist theses, and (ii) epistemologically, forced to give up Kant’s ideal that all necessities are known a priori. (shrink)

This book consists of an introduction by the editor, eleven of Plantinga’s previously published pieces, and an index. The previously published works are presented in the following chronological order: “De Re et De Dicto” (1969); “World and Essence” (1970); “Transworld Identity or Worldbound Individuals?” (1973); Chapter VIII of The Nature of Necessity (1974); “Actualism and Possible Worlds” (1976); “The Boethian Compromise” (1978); “De Essentia” (1979); “On Existentialism” (1983); “Reply to John L. Pollock” (1985); “Two Concepts of Modality: Modal Realism (...) and Modal Reductionism” (1987); and “Why Propositions Cannot Be Concrete” (1993). (shrink)

In this essay I comparatively evaluate two realist metaphysical accounts of modality: David Lewis’ (1986) genuine modal realism (GMR), and neo-Aristotelian modal realism (AMR) as put forth by Alexander Pruss (2011). GMR offers a reductive analysis of modal claims of possibility and necessity in terms of claims quantifying over concrete worlds and counterparts, and is in this way committed the existence of a plurality of concrete worlds other than the actual world; AMR, on the other hand, offers an analysis (...) of modal claims in terms of claims about the causal powers of existing objects in the actual world, and identifies these powers and powerful properties as the truthmakers for modal truths of possibility and necessity. I consider two objections to GMR; firstly, that it leads to ethical paradoxes, and secondly, that the counterparts it offers as truthmakers for modal claims are fundamentally irrelevant to the de re modal properties of objects. I argue that AMR bears a prima facie advantage over GMR by reason of its avoidance of those two objections, before evaluating two objections faced by AMR itself, namely, that its analysis is not genuinely explanatory, and secondly, that the ontology of powers fails to account for the full range of metaphysical possibility. I argue that AMR has the resources to avoid these objections, that AMR on balance is more attractive, and that therefore AMR is worthy of serious consideration by advocates of GMR. References LEWIS, DAVID K. (1986). On the plurality of worlds. New York, NY, USA: B. Blackwell. PRUSS, ALEXANDER R. (2011). Actuality, Possibility, and Worlds. London: Continuum. (shrink)

In this work Ockham proposes a theory of simple predication, which he uses in explicating the truth conditions of progressively more complicated kinds of propositions. His discussion includes what he takes to be the correct semantic treatment of quantified propositions, past tense and future tense propositions, and modal propositions, all of which are receiving much attention from contemporary philosophers. He also illustrates the use of exponential analysis to deal with propositions that prove troublesome in both semantic theory and other disciplines, (...) such as metaphysics, physics, and theology. This type of analysis plays an essential role in his substantive philosophical and theological works, and in many cases then can hardly be understood without a prior acquaintance with this section of the Summa. An introduction by Alfred J. Freddoso clarifies and summarizes Ockham's theory, discusses certain philosophical problems which it engenders, and proposes new interpretations for parts of it. The essay will be helpful both to those interested in Ockham as a historical figure and to those interested in his substantive systematic contributions to logical theory. (shrink)

This thesis is a study on the nature of modality in Hegel’s Logic and contemporary modal metaphysics. The thesis has two aims: Firstly, it examines Lewisian modal realism, as well as the post-Lewisian modal metaphysical accounts of modal actualism and modal essentialism in order to reveal that each position appeals to a non-modal foundation to make modal concepts explicit. Each position thus falls under what Hegel regards as pre-critical metaphysics by suggesting a modally unaccountable ground for modal (...) concepts. The very idea of a foundation to modality is problematic because as a foundation, it is necessarily assumed without further justification, and it directs our attention away from the nature of modality itself to its supposed foundations. These non-modal foundational take the form of possible worlds for modal realism, the form of properties for modal actualism and the form of essence for modal essentialism. To eschew foundationalism in modal metaphysics and provide a less questionable basis for modality, the thesis suggests Hegel’s treatment of modality as a viable alternative in virtue of its being free from the concerns stemming from the pre-critical way of doing metaphysics. The thesis situates Hegel in contemporary modal metaphysics by undertaking two types of exposition. By examining Hegel's treatment of essence and property, the thesis will show negatively that essence and property cannot be a foundation for modality, while by examining Hegel’s treatment of modality, the thesis positively proves that modal concepts are analysable and explainable within the domain of actuality, a domain that can only be made explicit by modal determinations. These two expositions provide an idea of a self-sustaining and self-explanatory modal metaphysics without appealing to non-modal foundationalist metaphysical commitments. More precisely, I argue that Hegel’s logical derivation of modal concepts constitutes a Hegelian modal metaphysics, which contains a comprehensive account of modal concepts that does not rely on any non-modal primitive. (shrink)