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.

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)

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.

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)

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

The ten new essays in this volume explore various answers to these questions, including those offered by contextualism, relativism, and expressivism.

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)

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)

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. This paper raises a problem for centered worlds and discusses the costs and benefits of different solutions. The present investigation into the nature of centered worlds helps to explicate potentially problematic implicit commitments of the theories that employ (...) them. In addition, this investigation reveals that the conception of centered worlds widely attributed to David Lewis is not only problematic, but in fact not his. (shrink)

According to the New Theory of Reference, proper names (and indexicals) and natural kind terms are semantically similar to each other but crucially different from definite descriptions and “ordinary” predicates, respectively. New Theorists say that a name, unlike a definite description, is a directly referential nondescriptional rigid designator, which refers “without a mediation of the content” and is not functional (i.e. lacks a Carnapian intension). Natural kind terms, such as ‘horse’ and ‘water’, are held to have similar distinctions, in contrast (...) to other predicates. However, the New Theory contains some problems related to reference, descriptionality, content and meaning. In view of these problems, it will be argued that the distinctive shared feature of proper names and natural kind terms, while technically corresponding to nonfunctionality, is to be explicated in terms of independence of possible worlds, rather than in terms of reference and content: natural kind terms are world-independent predicates, making “worldless” predications. Just as, say, ‘Elvis’ names Elvis even with respect to “Elvisless” worlds, or, rather, names Elvis independently of worlds, natural kind terms are in an important sense “worldless” as well: to talk about Elvis is to talk about him irrespective of moments of time and possible worlds, and is to talk about a human, also irrespective of moments and worlds, while it is not to talk about, say, a drug-addict irrespective of moments, nor about a singer irrespective of worlds. There is no genuinely timeless and worldless predication of the sort “Elvis is (was) bald”, but there is, it seems, such a predication “Elvis is (was) human”. This notion of independence of times and worlds is detached from those of descriptionality and content mediation. (shrink)

I have three main objectives in this essay. First, in chapter 2, I shall put forward and justify what I call worldlessness, by which I mean the following: All truths (as well as falsehoods) are wholly independent of any circumstances, not only time and place but also possible worlds. It follows from this view that whatever is actually true must be taken as true with respect to every possible world, which means that all truths are (in a sense) necessary. However, (...) the account I shall propound is different from what is known in the trade as necessitarianism, i.e. the view that there is only one possible world, viz. the actual one, for the doctrine of the worldlessness of truth values, despite its commitment to the necessity of truths and falsehoods, is quite compatible with the idea of there being other possible worlds. Another important issue in chapter 2, explored in particular in section 2.12, is the claim that there is no real change in the world. Secondly, in chapter 3 I consider the eminent traditional argument for determinism, deriving from Aristotle, namely, logical determinism, i.e. determinism justified by an appeal to the logical principle of bivalence (that all proper statements, including those concerning the future, are either true or false). In this connection I try to show that, (i), the formulation of the conclusion of this argument as "Whatever will happen will happen of necessity" is implausible, at least from the modern point of view, (ii), the formulation as "Whatever will happen will happen inevitably" is more to the point, and (iii), on the basis of the worldless and timeless aspect advocated in chapter 2, this latter formulation is quite harmless, essentially amounting to the trivial statement, "Whatever will happen will happen". Thirdly, in chapter 4 I study theological determinism, or determinism that arises from God's supposed providential control over everything that happens. In this connection, I shall survey some historical accounts of the relation between human free will and determinism (not only theological but also causal determinism); the philosophers the views of whom I shall attend to include Chrysippus, St. Augustine, Boethius and Aquinas. I shall in particular consider G.W. Leibniz' theodicean aspirations, viz. his solution to the problem of evil and, especially, his compatibilist attempts to reconcile human free will with the strictly deterministic flow of actual events. I think it is important to try to explicate Leibniz' ingenious account of these matters, since it seems that it has not been fully appreciated in the literature, not even by contemporary Leibniz scholars (such as B. Mates, R.C. Sleigh, C. Wilson, R.M. Adams and D. Rutherford). In providing the Leibnizian compatibilist solution of the problem of determinism and freedom in chapter 4, I shall utilize the approach of chapter 2. (shrink)

In this paper, an argument of Alvin Plantinga's for the existence of abstract possible worlds is shown to be unsound. The argument is based on a principle Plantinga calls "Quasicompactness", due to its structural similarity to the notion of compactness in first-order logic. The principle is shown to be false.

In this essay I respond to Quentin Smith's chargethat `the date-analysis version ofthe tenseless theory of time cannot give adequateaccounts of the truth conditions ofthe statements made by tensed sentence-tokens'(Smith 1999, 236). His argument isbased on an analysis of certain counterfactualsituations that is at odds with thedate-analysis account of language and hence succeedsonly in begging the questionagainst that theory. To anticipate: his argumentfails if one allows that temporalindexicals such as `now' rigidly designate theirtime of utterance, something thedate-analyst can happily admit (...) whether she adheresto an absolute or relationalmetaphysics of time. (shrink)

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

This book discusses a range of important issues in current philosophical work on the nature of possible worlds. Areas investigated include the theories of the nature of possible worlds, general questions about metaphysical analysis and questions about the direction of dependence between what is necessary or possible and what could be.

Analytic philosophers usually think about modality in terms of possible worlds. According to the possible worlds framework, a proposition is necessary if it is true according to all possible worlds; it is possible if it is true according to some possible world. There are as many possible worlds as there are ways the actual world might be. Only one world is actual.

This book is a survey, fortified by original material, of metaphysical theories of modality set in terms of possible worlds. Those theories include what Divers calls “genuine realism”, or “GR” — this is David Lewis’s “genuine modal realism” — and what Divers calls “actualist realism”, or “AR” — this seems to be the same as what Lewis called “ersatz modal realism”, which has also become widely know as “ersatzism”. Two important kinds of theory are not included: those that treat modality (...) by means not involving possible worlds at all (for example, modalism, various kind of non-cognitivism, and Quinean eliminativism about modality); and those that, while treating modality by talking about possible worlds, go on to deny that there are any possible worlds in one way or another (for example, Rosen’s fictionalism, and Divers’ own agnosticism about possible worlds). These get a short discussion towards the end of the introductory part of the book (sections 2.4–2.6), and Divers is planning to write a companion volume covering them. (shrink)

In this paper I explore the relationship between the idea of possible worlds and the notion of the beauty of God. I argue that there is a clear contradiction between the idea that God is utterly and completely beautiful on the one hand and the notion that He contains within himself all possible worlds on the other. Since some of the possible worlds residing in the mind of the deity are ugly, their presence seems to compromise God's complete and utter (...) beauty. (shrink)

Possible worlds are maximal possibilities. But what kind of thing is a maximal possibility? Not a maximal individual: there are maximal possibilities that are not maximal individuals, because each maximal individual could have any one of several maximal properties. And not a maximal property: there are maximal possibilities that are not maximal properties, because each maximal property could be had by any one of many possible maximal individuals. So if you like your worlds concrete, you should say that they are (...) maximal facts, and if you like your worlds abstract, you should say that they are maximal propositions. (shrink)

Possible worlds present a formidable challenge for the lover of desert landscapes. One cannot ignore their usefulness; they provide, as David Lewis puts it, “a philosophers’ paradise”.1 But to enter paradise possibilia must be fit into a believable ontology. Some follow Lewis and accept worlds at face value, but most prefer some other choice from the current menu. Part of Chihara’s book is a critical discussion of some of these menu options: Lewis’s modal realism, Alvin Plantinga’s abstract modal realism, (...) Graeme Forbes’s anti-realism and Gideon Rosen’s modal fictionalism. These discussions are very detailed and conversant with the literature. The discussions of Forbes (pp. 142-167) and of paradox within Plantinga’s system (pp. 120-141) are particularly enlightening. The rest of the book is devoted to Chihara’s positive project: developing an account of the status of model theory for non-modal logic, and then applying it to the modal case. The prize is an understanding of possible worlds semantics that requires no commitment to possible worlds at all (beyond the purely formal “possible worlds” of the standard Kripke-models.) What does the relativized notion of truth in an interpretation studied in (non-modal) model theory have to do with plain old truth? Chihara’s answer involves “connecting theorems” that relate truth-in to truth (chapter 5). A “natural-language proto-interpretation of the sentential calculus” (NLPI of SC) is a function that assigns meanings of declarative sentences of English to sentence letters. Where I is an NLPI of SC and φ is a sentence letter, Chihara uses ‘[φ/I ]’ to refer to “φ with the meaning it has been assigned by I ” (p. 191); where φ is not atomic, he says (p. 192). (shrink)

I argue that if a subject's acquaintance with an object is necessary for him to think about and refer to the object, then the content of his thought cannot be a set of metaphysically possible worlds. Acquaintance resets what possibilities there are; it affects the powers of representation, and does not only limit the range of possibilities. If acquaintance restricts what a subject can think about, the theorist cannot specify what possibilities are open to the subject simply in terms of (...) possible worlds. (shrink)

Australasian Journal of Philosophy, Volume 89, Issue 4, Page 755-756, December 2011.

In the debate about the nature and identity of possible worlds, philosophers have neglected the parallel questions about the nature and identity of moments of time. These are not questions about the structure of time in general, but rather about the internal structure of each individual time. Times and worlds share the following structural similarities: both are maximal with respect to propositions (at every world and time, either p or p is true, for every p); both are consistent; both are (...) closed (every modal consequence of a proposition true at a world is also true at that world, and every tense-theoretic consequence of a proposition true at a time is also true at that time); just as there is a unique actual world, there is a unique present moment; and just as a proposition is necessarily true iff true at all worlds, a proposition is eternally true iff true at all times. In this paper, I show that a simple extension of my theory of worlds yields a theory of times in which the above structural similarities between the two are consequences. (shrink)