Alvin Plantinga’s solution to J. L. Mackie’s logical problem of evil invokes possible-worlds metaphysics. There are reasons for thinking that the solution is, at least, problematic. Difficulties emerge in the attempts to answer four related questions. Can God’s necessary existence, understood in terms of possible-world metaphysics, make God’s actual existence impossible to explain? Can an omniscient being with knowledge of the contents of every possible world prove ignorant of the consequences of his creative acts? Can (...) an immoral action performed by an agent suffering from “transworld depravity” also be free in the libertarian sense? Does the possible-worlds interpretation of libertarian freedom generate a vicious infinite regress? Special focus is on the possibility, advanced by Plantinga, that there are possible worlds that even an omnipotent being cannot create. Plantinga’s views are contrasted with those of Thomas Aquinas. (shrink)

In "A Problem in Possible-World Semantics," David Kaplan presented a consistent and intelligible modal principle that cannot be validated by any possible world frame (in the terminology of modal logic, any neighborhood frame). However, Kaplan's problem is tempered by the fact that his principle is stated in a language with propositional quantification, so possible world semantics for the basic modal language without propositional quantifiers is not directly affected, and the fact that on careful inspection his (...) principle does not target the world part of possible world semantics—the atomicity of the algebra of propositions—but rather the idea of propositional quantification over a complete Boolean algebra of propositions. By contrast, in this paper we present a simple and intelligible modal principle, without propositional quantifiers, that cannot be validated by any possible world frame precisely because of their assumption of atomicity (i.e., the principle also cannot be validated by any atomic Boolean algebra expansion). It follows from a theorem of David Lewis that our logic is as simple as possible in terms of modal nesting depth (two). We prove the consistency of the logic using a generalization of possible world semantics known as possibility semantics. We also prove the completeness of the logic (and two other relevant logics) with respect to possibility semantics. Finally, we observe that the logic we identify naturally arises in the study of Peano Arithmetic. (shrink)

Alvin Plantinga’s solution to J. L. Mackie’s logical problem of evil invokes possible-worlds metaphysics. There are reasons for thinking that the solution is, at least, problematic. Difficulties emerge in the attempts to answer four related questions. (1) Can God’s necessary existence, understood in terms of possible-world metaphysics, make God’s actual existence impossible to explain? (2) Can an omniscient being with knowledge of the contents of every possible world (a being endowed with “middle knowledge”) prove ignorant (...) of the consequences of his creative acts? (3) Can an immoral action performed by an agent suffering from “transworld depravity” also be free in the libertarian sense? (4) Does the possible-worlds interpretation of libertarian freedom generate a vicious infinite regress? Special focus is on the possibility, advanced by Plantinga, that there are possible worlds that even an omnipotent being cannot create. Plantinga’s views are contrasted with those of Thomas Aquinas. (shrink)

It is sometimes argued that if God were to exist, then the actual world would be the best possible world. However, given that the actual world is clearly not the best possible world, then God doesn’t exist. In response, some have argued that the world could always be improved with the creation of new people and that there is thus no best possible world. I argue that this reasoning gives rise to an instance of Parfit’s mere addition (...) paradox and should thus be rejected. Others (Robert Adams, in particular) have argued that the actual world may, in fact, be the best possible world, at least for all actual people. I argue that this reasoning gives rise to Parfit’s non-identity problem and should thus be rejected. (shrink)

Using four principles common to several theories about possible worlds, It is argued that the necessary existence of a divine being that is essentially omnipotent, Omniscient, And morally perfect is impossible. The central argument employs the premise that there are possible worlds that any divine being ought not to actualize (because of their evil contents). This premise is then defended on the grounds that the same sort of justification that we give for other modal statements that (...) we accept can be given for modal statements which entail the premise. It is concluded that we must reject the guiding principle that gives rise to the traditional theistic concept, Viz., That if a property p of an individual is an excellence of it and hence its having p is good, Then its having p necessarily or essentially is better. (shrink)

The canonical version of possible worlds semantics for story prefixes is due to David Lewis. This paper reassesses Lewis's theory and draws attention to some novel problems for his account.

The article investigates the sceptical challenge from an informationtheoretic perspective. Its main goal is to articulate and defend the view that either informational scepticism is radical, but then it is epistemologically innocuous because redundant; or it is moderate, but then epistemologically beneficial because useful. In order to pursue this cooptation strategy, the article is divided into seven sections. Section 1 sets up the problem. Section 2 introduces Borei numbers as a convenient way to refer uniformly to (the data that (...) individuate) different possible worlds. Section 3 adopts the Hamming distance between Borei numbers as a metric to calculate the distance between possible worlds. In Sects. 4 and 5, radical and moderate informational scepticism are analysed using Borei numbers and Hamming distances, and shown to be either harmless (extreme form) or actually fruitful (moderate form). Section 6 further clarifies the approach by replying to some potential objections. In the conclusion, the Peircean nature of the overall approach is briefly discussed. (shrink)

Metaphysically possible worlds have many uses. Epistemically possible worlds promise to be similarly useful, especially in connection with propositions and propositional attitudes. However, I argue that there is a serious threat to the natural accounts of epistemically possible worlds, from a version of Russell’s paradox. I contrast this threat with David Kaplan’s problem for metaphysical possible world semantics: Kaplan’s problem can be straightforwardly rebutted, the problems I raise cannot. I argue that (...) although there may be coherent accounts of epistemically possible worlds with fruitful applications, any such an account must fundamentally compromise the basic idea behind epistemic possibility. (shrink)

Actualists who believe in possible worlds typically regard them as "abstract" objects of some special sort. For example, Alvin Plantinga takes worlds to be maximal possible states-of-affairs, all of which "exist", as actualism requires, but only one of which "obtains". Views like Plantinga's run into difficulty in the interpretation of statements of "iterated" modality, statements about what is "possible" for individuals that "could" exist but that do not actually exist. These statements seem to require the (...) existence of "singular" states-Of-affairs that have nonactual individuals as constituents, a requirement that is incompatible with actualism. One can try to avoid the troublesome singular states-of-affairs by introducing "unexemplified individual essences" and maintaining that these are the true constituents of the required states-of-affairs, rather than the nonactual possibles themselves. However, serious arguments are raised against this employment of individual essences. (shrink)

If □ is conceived as an operator, i.e., an expression that gives applied to a formula another formula, the expressive power of the language is severely restricted when compared to a language where □ is conceived as a predicate, i.e., an expression that yields a formula if it is applied to a term. This consideration favours the predicate approach. The predicate view, however, is threatened mainly by two problems: Some obvious predicate systems are inconsistent, and possible-worlds semantics for (...) predicates of sentences has not been developed very far. By introducing possible-worlds semantics for the language of arithmetic plus the unary predicate □, we tackle both problems. Given a frame (W, R) consisting of a set W of worlds and a binary relation R on W, we investigate whether we can interpret □ at every world in such a way that □ $\ulcorner A \ulcorner$ holds at a world ᵆ ∊ W if and only if A holds at every world $\upsilon$ ∊ W such that ᵆR $\upsilon$ . The arithmetical vocabulary is interpreted by the standard model at every world. Several 'paradoxes' (like Montague's Theorem, Gödel's Second Incompleteness Theorem, McGee's Theorem on the ω-inconsistency of certain truth theories, etc.) show that many frames, e.g., reflexive frames, do not allow for such an interpretation. We present sufficient and necessary conditions for the existence of a suitable interpretation of □ at any world. Sound and complete semi-formal systems, corresponding to the modal systems K and K4, for the class of all possible-worlds models for predicates and all transitive possible-worlds models are presented. We apply our account also to nonstandard models of arithmetic and other languages than the language of arithmetic. (shrink)

This paper is about possible worlds semantics for propositional attitude sentences. In particular I shall focus on belief reports in English such as "Lusina believes that tofu is nutritious." It is well-known that possible worlds semantics for such reports suffers from the so-called _problem of equivalence_ . In this paper I shall examine some attempts to deal with this problem and argue that they are unsatisfactory.

Saul Kripke did more than anyone else to bring possible worlds into the contemporary philosophical discourse, first with his more formal work on the model theory for modal logic in the 1960s, and then with his more philosophical lectures on reference and modality, delivered in January 1970, that used the possible worlds apparatus informally to clarify the relations between semantic issues about names and metaphysical issues about individuals and kinds. Possible worlds semantics have been (...) widely applied since then, both in philosophy and in other fields such as linguistic semantics and pragmatics, theoretical computer science, and game theory. Kripke’s work, along with that of David Lewis, stimulated an ongoing debate about the nature and metaphysical status of possible worlds. Kripke himself has had little to say about the issues raised in this debate, in print, beyond what he said in Naming and Necessity and in brief remarks in a preface to a later edition of the lectures, published in 1980. But there is a clear view of the nature of possible worlds, and of the status of an explanation of modality in terms of possible worlds, implicit in the lectures and the preface. -/- The central focus of the post–Naming and Necessity debate about possible worlds has been a contrast between David Lewis’s modal realism and various versions of actualism. On this general issue, it is clear enough where Kripke stands: His criticisms of what he describes as the “other countries” picture of possible worlds are an explicit rejection of Lewis’s realism about possible worlds. But the rejection of modal realism raises a range of further questions: What exactly are possible worlds (or possible states of the world, which Kripke suggests would be less misleading terminology)? What contribution do they make to the explanation of modal discourse, and of the distinctive facts that modal discourse is used to state? Does the slogan “necessity is truth in all possible worlds” provide, or point to, a reductive analysis of necessity? Are possible worlds, in some sense, prior to modal operators and modal auxiliaries? If not, in what sense are they explanatory? How are possible worlds, or counterfactual situations, specified? How do they contribute to our understanding of specific meta- physical questions about the relations between particular individuals and their qualitative characteristics, the kinds to which they belong, and the matter of which they are constituted? How are we to understand the possible existence of individuals that do not actually exist? What is the status of the domains of individuals in merely possible worlds? -/- My aim in this chapter is to spell out the views about some of these foundational questions that are expressed or at least implicit in Kripke’s lectures. In Section 2, I discuss the general contrast between modal realism and actualism and questions about the kind of explanation that possible worlds provide for modal discourse and modal facts. In Section 3, I look at Kripke’s views about how possible worlds are specified, in particular at the role of individuals in specifying possible worlds. In Section 4, I consider the problems about merely possible individuals. (shrink)

The numerous difficulties facing the traditional Humean regularity approach to the problem of causation have been discussed in the literature at great length. In view of the current interest in possible worlds semantics, it is not surprising that the only serious alternative treatment of causation presently available, the counterfactual approach, has been explored recently as a means of circumventing the apparently unresolvable difficulties facing regularity causal theories. It is the purpose of this paper to suggest that such (...) a strategy holds little promise. Specifically, I will argue that, in addition to giving rise to problems directly analogous to those facing regularity accounts, the counterfactual approach fails in principle to reflect important properties of causal relations as we understand them intuitively. David Lewis's possible worlds account, the most comprehensive counterfactual theory to date, is further criticized for implicit problems with natural lawhood even more serious than those typically raised for regularity accounts, for additional inadequacies in its analysis of causal relations, and for its failure to satisfy basic empiricist epistemological standards. (shrink)

The paper is a brief survey of the most important semantic constructions founded on the concept of possible world. It is impossible to capture in one short paper the whole variety of the problems connected with manifold applications of possible worlds. Hence, after a brief explanation of some philosophical matters I take a look at possible worlds from rather technical standpoint of logic and focus on the applications in formal semantics. In particular, I would like (...) to focus on the fruitful marriage of possible world semantics and algebra and its evolution leading to very general construction of Wójcicki called referential semantics and some of its refinements. The presentation is informal and sketchy; the main purpose is to put in one place a short, and readable I hope, description of the most important constructions and to point out the main sources of these solutions. (shrink)

Das problem der welt, nach der auffassung der moglichen welt-semantik, ist nur implizit vorhanden. bis heute gibt es nur eine allgemeine auffassung der welt im einverstandnis mit der intuition der moglichen welten. die fragestellung ist: wie kann ein gegenstand identifiziert werden und warum kann von dessen existenz gesprochen werden? der logisch-semantische streit geht quer durch das verfahren der universellen "instantijerung" und der existenziellen generalisation. das problem der eigenschaften in der kausalen namenserklarung wird durch die bestimmung des kunftigen, durch (...) vergangenes, also durch die these der starrheit gelost. unserer meinung nach, ist hier das verfahren der "moglichen welten" eine art kaleidoskop der referenz der eigennament. dies fuhrt dazu, dass entitaten sich verveilfachen und in verschiedenen "welten" alle gleich erscheinen. daruber hinaus mussen eigenschaften bei der beschreibung eines objekts wesentlich sein. dadurch werden grade der diskriminalitat eingefuhrt, die nicht akzeptierbar sind. (shrink)

Fictionalism about possible worlds is the view that talk about worlds in the analysis of modality is to be construed as ontologically innocent discourse about the content of a fiction. Versions of the view have been defended by D M Armstrong (in "A Combinatorial Theory of Possibility") and by myself (in "Modal Fictionalism', "Mind" 99, July 1990). The present note argues that fictionalist accounts of modality (both Armstrong's version and my own) fail to serve the fictionalists ontological (...) purposes because they imply that as a matter of necessity there exist many worlds. (shrink)

Well‐known arguments for atheism have been grounded on the alleged lack of morally justifying reasons to permit particular moral and natural evils and on the thesis that God would have to create the best possible world. After discussing obstacles to the suggestion that there is a best of all possible worlds, I examine the prospects for responding to these atheistic arguments by exploring the case for our own world's being the best of all possible worlds (...) against the backdrop of the multiverse hypothesis – an intriguing claim about the partitioned structure of reality that has been receiving serious and recent attention in philosophy and physics. (shrink)

This thesis is an argument for the view that there are problems for Modal Reductionism, the thesis that modality can satisfactorily be defined in non-modal terms. -/- I proceed via a case study of David Lewis’s theory of concrete possible worlds. This theory is commonly regarded as the best and most influential candidate reductive theory of modality. Based on a detailed examination of its ontology, analysis and justification, I conclude that it does badly with respect to the following (...) four minimal conditions on a satisfactory reductive theory of modality: that it be (a) genuinely reductive, (b) materially adequate, (c) conceptually adequate and (d) that its justification provides good reason to think it true. -/- These problems for Lewis’s theory are not, I suggest, due to his idiosyncratic conception of possible worlds as concrete entities. Rather, because Lewis’s theory can be seen to represent an important class of structurally similar reductive theories of modality, the problems for Lewis’s theory generalise to problems for these other theories. This suggests that Modal Reductionism is unpromising. In the light of this, the alternative approach to understanding modality, Modal Primitivism, appears more attractive. (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)

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)

Dualism about possible worlds says that merely possible worlds aren’t concrete objects, but the actual world is concrete. This view seems to be the natural one for ersatzers about merely possible worlds to take; yet one is hard-pressed to find any defenders of it in contemporary modal metaphysics. The main reason is that Dualism struggles with the issue of how merely possible worlds could have been actual. I explain that there are two (...) different Dualist strategies that can be taken to address the problem. Furthermore, one or other of these strategies should be plausible to anyone who accepts both Existentialism—which tells us that the existence of singular propositions depends on what they directly refer to—and Serious Actualism—which tells us that things must exist in order to instantiate properties. Though it has long been ignored, Dualism is a live option. (shrink)

This thesis examines the alethic modal concepts of possibility and necessity. It is argued that one cannot do justice to all our modal talk without possible worlds, i.e., complete ways that a cosmos might have been. I argue that not all of the proposed applications of possible worlds succeed but enough remain to give one good theoretical reason to posit them. The two central problems now are: What feature of reality makes correct alethic modal claims true (...) and What are possible worlds? ;David Lewis makes possible worlds be concretely existing universes. Unfortunately, I show Lewis's account involves set-theoretic, ethical, inductive and probabilistic paradoxes, and commits Lewis to an objectionable form of primitive modality that governs the choice of the counterpart relation. The most promising contemporary alternatives to Lewis's theory have been the worlds of Adams and Plantinga constructed out of Platonic entities such as maximal collections of consistent propositions. However, these approaches fail to provide a satisfactory answer to the question of what makes true modal claims true. I also criticize some alternative accounts. ;Finally, I discuss and combine two historical approaches. The first is an Aristotelian approach that says a non-actual event is possible is to say that some actual substances could have initiated a causal chain that could lead up to the event in question. However, it can be shown that some plausible global possibility claims can be made true on this account only if there is a necessarily existent first cause capable of initiating very different universes. On the other hand, Leibniz made possible worlds be ideas in the mind of an omniscient necessarily existent deity. Leibniz fails to explain what it is that makes these possible worlds possible, but if we were willing to combine his story with the conclusion drawn from the Aristotelian one, we could get the following story: Possible worlds are ideas in the mind of an omniscient deity and what makes them possible is that this deity has the Aristotelian capability of initiating causal chains that can lead to them being actualized. (shrink)

In a recent article Mark Ian Thomas Robson argues that there is a clear contradiction between the view that possible worlds are a part of God's nature and the theologically pivotal, but philosophically neglected, claim that God is perfectly beautiful. In this article I show that Robson's argument depends on several key assumptions that he fails to justify and as such that there is reason to doubt the soundness of his argument. I also demonstrate that if Robson's argument (...) were sound then this would be a problem for all classical theists and not just those who hold the possible worlds view. (shrink)

Over a longer period than I sometimes care to contemplate I have worked on possible-worlds semantics. The earliest work was in modal logic, to which I keep returning, but a sabbatical in 1970 took me to UCLA, there to discover the work of Richard Montague in applying possible-worlds semantics to natural lan guage. My own version of this appeared in Cresswell (1973) and was followed up in a number of articles, most of which were collected in (...) Cresswell (1985b). A central problem for possible worlds semantics is how to accommodate propositional attitudes. This problem was addressed in Cresswell (1985a), and the three books mentioned so far represent a reasonably complete picture of my positive views on formal semantics. I have regarded the presentation of a positive view as more important than the criticism of alternatives, although the works referred to do contain many passages in which I have tried to defend my own views against those of others. But such criticism is important in that a crucial element in establishing the content of a theory is that we be able to evaluate it in relation to its com petitors. It is for that reason that I have collected in this volume a number of articles in which I attempt to defend the positive semantical picture I favour against objections and competing theories. (shrink)

The article is devoted to the problem of interpreting of the several consequences that derive from multi-world concepts of modern physics. The inflation scenario and the associated string landscape model are the objects of analysis. The reviewed multi-world concepts are exposed to presume the existence of a plenitude of various fundamental principles that govern the physics of one or another possible reality. The research is based on the hermeneutical method, comparative method, dialectical method, formal translation method, and scientific (...) modeling method. The author represents specifics of physical theories that claim to describe all possible worlds in the conclusions. In this regard, the issues of the status of “possible” and “impossible” worlds and practicable ways to determine them are discussed. The main result of the study is the justification that each type of world must correspond to a certain structure of consciousness defined by its basic physical principles. This possibly means that a unified “theory of everything” that includes all possible mathematical and physical fundamental structures cannot exist since every one of them determines a specific type of consciousness. (shrink)

Zwart and Franssen’s impossibility theorem reveals a conflict between the possible-world-based content-definition and the possible-world-based likeness-definition of verisimilitude. In Sect. 2 we show that the possible-world-based content-definition violates four basic intuitions of Popper’s consequence-based content-account to verisimilitude, and therefore cannot be said to be in the spirit of Popper’s account, although this is the opinion of some prominent authors. In Sect. 3 we argue that in consequence-accounts , content-aspects and likeness-aspects of verisimilitude are not in conflict with (...) each other, but in agreement . We explain this fact by pointing towards the deep difference between possible-world- and the consequence-accounts, which does not lie in the difference between syntactic (object-language) versus semantic (meta-language) formulations, but in the difference between ‘disjunction-of-possible-worlds’ versus ‘conjunction-of-parts’ representations of theories. Drawing on earlier work, we explain in Sect. 4 how the shortcomings of Popper’s original definition can be repaired by what we call the relevant element approach. We propose a quantitative likeness-definition of verisimilitude based on relevant elements which provably agrees with the qualitative relevant content-definition of verisimilitude on all pairs of comparable theories. We conclude the paper with a plea for consequence-accounts and a brief analysis of the problem of language-dependence (Sect. 6). (shrink)

In this paper, I shall consider the challenge that Quine posed in 1947 to the advocates of quantified modal logic to provide an explanation, or interpretation, of modal notions that is intuitively clear, allows “quantifying in”, and does not presuppose, mysterious, intensional entities. The modal concepts that Quine and his contemporaries, e.g. Carnap and Ruth Barcan Marcus, were primarily concerned with in the 1940’s were the notions of (broadly) logical, or analytical, necessity and possibility, rather than the metaphysical modalities that (...) have since become popular, largely due to the influence of Kripke. In the 1950’s modal logicians responded to Quine’s challenge by providing quantified modal logic with model-theoretic semantics of various types. In doing so they also, explicitly or implicitly addressed Quine’s interpretation problem. Here I shall consider the approaches developed by Carnap in the late 1940’s, and by Kanger, Hintikka, Montague, and Kripke in the 1950’s, and discuss to what extent these approaches were successful in meeting Quine’s doubts about the intelligibility of quantified modal logic. (shrink)

Essay on philosophical problems with police sting operations and the legal doctrine of entrapment.

The Brock-Rosen problem has been one of the most thoroughly discussed objections to the modal fictionalism bruited in Gideon Rosen’s ‘Modal Fictionalism’. But there is a more fundamental problem with modal fictionalism, at least as it is normally explained: the position does not resolve the tension that motivated it. I argue that if we pay attention to a neglected aspect of modal fictionalism, we will see how to resolve this tension—and we will also find a persuasive reply to (...) the Brock-Rosen objection. Finally, I discuss an alternative reading of Rosen, and argue that this position is also able to fend off the Brock-Rosen objection. (shrink)

This collection brings together nine essays addressing the problem of compossibility in Leibniz's system of thought. The problem of compossibility is that of determining by what mechanism two independently possible substances are jointly possible, and thus do form part of the same possible world. The collection opens with an excellent introduction to the terrain, reviews established approaches to the problem, and will be extremely helpful to both those new to, and those familiar with, Leibniz.Adam (...) Harmer's essay provides a detailed analysis of the "world apart" doctrine, for which he considers three different interpretations: causal, ontological, and phenomenal, as well as weak and strong forms... (shrink)

Pietroski (1993) offers a semantics for belief sentences that is supposed to address the problem of equivalence. This paper argues that his proposal fails to solve the problem.

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)

The standard view of clauses embedded under attitude verbs or modal predicates is that they act as terms standing for propositions, a view that faces a range of philosophical and linguistic difficulties. Recently an alternative has been explored according to which embedded clauses act semantically as predicates of content-bearing objects. This paper argues that this approach faces serious problems when it is based on possible worlds-semantics. It outlines a development of the approach in terms of truthmaker theory instead.

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)

This book uses the formal semantics of counterfactual conditionals to analyze the problem of non-locality in quantum mechanics. Counterfactual conditionals enter the analysis of quantum entangled systems in that they enable us to precisely formulate the locality condition that purports to exclude the existence of causal interactions between spatially separated parts of a system. They also make it possible to speak consistently about alternative measuring settings, and to explicate what is meant by quantum property attributions. The book develops (...) the possible-world semantics of quantum counterfactuals using David Lewis's famous approach as a starting point but modifying it significantly in order to achieve compatibility with the demands of the special theory of relativity as well as quantum mechanics. There have been several attempts to use counterfactuals semantics to strengthen Bell's theorem and its cognates such as the GHZ and Hardy theorems. These are critically evaluated in the book. Finally, a counterfactual reconstruction of the EPR argument and Bell's theorem is proposed that sheds a new light on their philosophical consequences regarding the relations between realism and local causation. (shrink)

In this essay I consider how God is related to possible worlds from a classically evangelical and Reformed perspective, contending that God’s essential perfections determine what is genuinely possible. I then consider briefly three views that take God to be a significant delimiter of possible worlds and offer some defense of one of those views, the view that there are many genuinely possible worlds that are equally and unsurpassably good and that God might (...) have chosen to actualize. I conclude by noting two significant implications of my position, one epistemological and the other concerning the problem of evil. (shrink)

The notion of possible worlds — once an abstruse offspring of Leibnizian theology — seems to enjoy a new lease on life in the hands of contemporary modal logicians and semanticists. The phrase “possible world” crops up with increasing frequency, and, as it is the case with many philosophical catchwords, its very familarity creates a presumption of understanding. Yet, although some related problems, particularly the one concerning cross-world identification of individuals, have received some critical scrutiny, the very (...) idea of possible worlds has been borrowed from Leibniz, and its intelligibility taken for granted even without its theological roots.My misgivings about this notion are not due to a prejudice against the concept of the possible itself: far from “passing” away, it remains a fundamental and irreplaceable element of human thought. (shrink)

THIS BOOK is, in effect, a sequel to the author’s Models for Modalities and purports to carry forward the case for the feasibility of a "possible-worlds" semantics. The main contention of the book is that such a semantics has its chief application in the study of propositional attitudes. But a good deal more than this is claimed, namely, applicability to the study of epistemic notions in general, to the study of causality and the language of the sciences, to (...) the exact study of phenomenology, to the linguistics, to the problem of "representation" in the arts, and even to the foundations of statistics and probability theory. (shrink)

The general issue addressed in this dissertation is: what do the models of formal model-theoretic semantics represent? In chapter 2, I argue that those of first-order classical logic represent meaning assignments in possible worlds. This motivates an inquiry into what the interpretations of first-order quantified model logic represent, and in Chapter 3 I argue that they represent meaning assignments in possible universes of possible worlds. A possible universe is unpacked as one way model reality (...) might be. The problem arises here as to how we are to understand the distinction between the actual and the possible as it relates to modal reality. ;Along with the development of the main arguments in Chapters 2 and 3, the dissertation assesses the status of semantic accounts or logical properties and relations. Specifically, what does the model-theoretic account of a logically possible situation add to the syntactic account ? ;Proofs of invalidity in terms of the models of formal semantics do not establish that it is possible for the premises to be true and the conclusion false, since a formal model is merely given by a consistent set of sentences. Unless there is some way to generate a non-formal model from a formal one, such proofs do not really go beyond syntactic notions. The dissertation ends by concluding that there is no way to generate a non-formal model from a formal one without relying on logical intuitions that are syntactical. ;Hence efforts to construct a semantic basis for model logic independent of syntactic commitments are misguided. However, in classical logic the independence of the semantic account from the syntactic one is grounded on the intuition that it is metaphysically possible for there to be a denumerably infinite totality of objects. (shrink)

Zwart and Franssen’s impossibility theorem reveals a conflict between the possible-world-based content-definition and the possible-world-based likeness-definition of verisimilitude. In Sect. 2 we show that the possible-world-based content-definition violates four basic intuitions of Popper’s consequence-based content-account to verisimilitude, and therefore cannot be said to be in the spirit of Popper’s account, although this is the opinion of some prominent authors. In Sect. 3 we argue that in consequence-accounts, content-aspects and likeness-aspects of verisimilitude are not in conflict with each (...) other, but in agreement. We explain this fact by pointing towards the deep difference between possible-world- and the consequence-accounts, which does not lie in the difference between syntactic versus semantic formulations, but in the difference between ‘disjunction-of-possible-worlds’ versus ‘conjunction-of-parts’ representations of theories. Drawing on earlier work, we explain in Sect. 4 how the shortcomings of Popper’s original definition can be repaired by what we call the relevant element approach. We propose a quantitative likeness-definition of verisimilitude based on relevant elements which provably agrees with the qualitative relevant content-definition of verisimilitude on all pairs of comparable theories. We conclude the paper with a plea for consequence-accounts and a brief analysis of the problem of language-dependence. (shrink)

In the last ten years or so, talk of “possible worlds” has become decidedly more fashionable from a logical point of view. And here fashion is well-justified: both from a logical and from a metaphysical point of view, the work of Saul Kripke on the concept of a possible world is as challenging as any contributions since the time of Leibniz himself. It is only fair, then, and indirectly flattering, to complain that Kripke is limiting himself as (...) a major philosopher in ways which Leibniz saw to be essential to balanced philosophy. We confine ourselves in this paper to just two crucial dimensions of philosophical depth when it comes to the concept of possible worlds. On the one hand, Leibniz saw the concept as one which raises very usefully many traditional problems of ethics, including those of free will and theodicy. On the other hand, Leibniz saw that questions about possible worlds may call for a radical approach to sane ontology. Such an approach, “revisionary metaphysics,” systematically reinterprets rather than dogmatically regurgitates the convictions of Plain Men and Theoretical Physicists about—to take a favorite example of Kripke’s—this single table’s being made of many distinct molecules. (shrink)