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.

This introduction to modality places the emphasis on the metaphysics of modality rather than on the formal semetics of quantified modal logic. The text begins by introducing students to the "de re/de dicto" distinction, conventionalist and conceptualist theories of modality and some of the key problems in modality, particularly Quine's criticisms. It then moves on to explain how possible worlds provide a solution to many of the problems in modality and how possible worlds themselves have been used to analyse notions (...) outside modality such as properties and propositions. Possible worlds introduce problems of their own and the book argues that to make progress with these problems a theory of possible worlds is required. The pros and cons of various theories of possible worlds are then examined in turn, including those of Lewis, Kripke, Adams, Stalnaker and Plantinga. (shrink)

David Armstrong's book is a contribution to the philosophical discussion about possible worlds. Taking Wittgenstein's Tractatus as his point of departure, Professor Armstrong argues that nonactual possibilities and possible worlds are recombinations of actually existing elements, and as such are useful fictions. There is an extended criticism of the alternative-possible-worlds approach championed by the American philosopher David Lewis. This major work will be read with interest by a wide range of philosophers.

We naturally think of the material world as being populated by a large number of individuals . These are things, such as my laptop and the particles that compose it, that we describe as being propertied and related in various ways when we describe the material world around us. In this paper I argue that, fundamentally speaking at least, there are no such things as material individuals. I then propose and defend an individual-less view of the material world I call (...) “generalism”. (shrink)

_Possible Worlds_ presents the first up-to-date and comprehensive examination of one of the most important topics in metaphysics. John Divers considers the prevalent philosophical positions, including realism, antirealism and the work of important writers on possible worlds such as David Lewis, evaluating them in detail.

Robert Stalnaker opposes the traditional view that knowledge of one's own current thoughts and feelings is the unproblematic foundation for all knowledge. He argues that we can understand our knowledge of our thoughts and feelings only by viewing ourselves from the outside, by seeing our inner lives as features of the world as it is in itself.

This is a book about the concept of a physical thing and about how the names of things relate to the things they name. It questions the prevalent view that names 'refer to' or 'denote' the things they name. Instead it presents a new theory of proper names, according to which names express certain special properties that the things they name exhibit. This theory leads to some important conclusions about whether things have any of their properties as a matter of (...) necessity. This will be an important book for philosophers in metaphysics and the philosophy of language, though it will also interest linguists concerned with the semantics of natural language. (shrink)

In this paper, I formulate, elucidate, and defend a version of modal realism with overlap, the view that objects are literally present at more than one possible world. The version that I defend has several interesting features: it is committed to an ontological distinction between regions of spacetime and material objects; it is committed to compositional pluralism, which is the doctrine that there is more than one fundamental part-whole relation; and it is the modal analogue of endurantism, which is the (...) doctrine that objects persist through time by being wholly present at each moment they are located. (shrink)

This book, one of the first full-length studies of the modalities to emerge from the debate to which Saul Kripke, David Lewis, Ruth Marcus, and others are contributing, is an exploration and defense of the notion of modality de re, the idea that objects have both essential and accidental properties. Plantinga develops his argument by means of the notion of possible worlds and ranges over such key problems as the nature of essence, transworld identity, negative existential propositions, and the existence (...) of unactual objects in other possible worlds. He also applies his logical theories to the elucidation of two problems in the philosophy of religion: the problem of evil and the ontological argument. (shrink)

When one considers one's own persistence over time from the first-person perspective, it seems as if facts about one's persistence are "further facts," over and above facts about physical and psychological continuity. But the idea that facts about one's persistence are further facts is objectionable on independent theoretical grounds: it conflicts with physicalism and requires us to posit hidden facts about our persistence. This essay shows how to resolve this conflict using the idea that imagining from the first-person point of (...) view is a guide to centered possibility , a type of possibility analyzed in terms of centered worlds. CiteULike Connotea Del.icio.us Digg Reddit Technorati What's this? (shrink)

Antihaecceitists believe that all facts about specific individuals—such as the fact that Fred exists, or that Katie is tall—globally supervene on purely qualitative facts. Haecceitists deny that. The issue is not only of interest in itself, but receives additional importance from its intimate connection to the question of whether all fundamental facts are qualitative or whether they include facts about which specific individuals there are and how qualitative properties and relations are distributed over them. Those who think that all fundamental (...) facts are qualitative are arguably committed to antihaecceitism. The goal of this paper is to point out some problems for antihaecceitism (and therefore for the thesis that all fundamental facts are qualitative). The article focuses on two common assumptions about possible worlds: (i) Sets of possible worlds are the bearers of objective physical chance. (ii) Counterfactual conditionals can be defined by appeal to a relation of closeness between possible worlds. The essay tries to show that absurd consequences ensue if either of these assumptions is combined with antihaecceitism. Then it considers a natural response by the antihaecceitist, which is to deny that worlds play the role described in (i) and (ii). Instead, the reply continues, we can introduce a new set of entities that are defined in terms of worlds and that behave the way worlds do on the haecceitist position. That allows the antihaecceitist to formulate antihaecceitist friendly versions of (i) and (ii) by replacing the appeal to possible worlds with reference to the newly introduced entities. This maneuver invites an obvious reply, however. If the new entities are the things that play the role we typically associate with worlds, as partially described by (i) and (ii), then it is natural to conclude that they really are the entities we talk about when we speak of worlds, so that haecceitism is true after all. (shrink)

I argue that the standard counterexamples to the identity of indiscernibles fail because they involve a commitment to a certain kind of primitive or brute identity that has certain very unpalatable consequences involving the possibility of objects of the same kind completely overlapping and sharing all the same proper parts. The only way to avoid these consequences is to reject brute identity and thus to accept the identity of indiscernibles. I also show how the rejection of the identity of indiscernibles (...) derives some of its support from its affinity with a Kripkean account of trans-world identity and theories of direct reference. (shrink)

The standard counterexamples to David Lewis’s account of intrinsicality involve two sorts of properties: identity properties and necessary properties. Proponents of the account have attempted to deflect these counterexamples in a number of ways. This paper argues that none of these moves are legitimate. Furthermore, this paper argues that no account along the lines of Lewis’s can succeed, for an adequate account of intrinsicality must be sensitive to hyperintensional distinctions among properties.

Substantivalists believe that spacetime and its parts are fundamental constituents of reality. Relationalists deny this, claiming that spacetime enjoys only a derivative existence. I begin by describing how the Galilean symmetries of Newtonian physics tell against both Newton's brand of substantivalism and the most obvious relationalist alternative. I then review the obvious substantivalist response to the problem, which is to ditch substantival space for substantival spacetime. The resulting position has many affinities with what are arguably the most natural interpretations of (...) special and general relativity. I move on to consider and reject two recent antisubstantivalist lines of thought. The interim conclusion is that the best argument for relationalism is an appeal to Ockham's razor. However, for this to be successful there must be genuine relationalist theories that share the theoretical virtues of their substantivalist rivals but without the additional ontological commitment. The bulk of the paper is therefore an investigation of various concrete relationalist proposals. I distinguish three options for the relationalist in the face of the success of Galilean invariant physics and trace how these generalise to relativistic physics. One of the options is particularly promising but, since its basic objects end up being spacetime points, this does not help the prospects of relationalism as traditionally conceived. I end with some reflections on the fate of substantivalism in the aftermath of the Hole Argument, concluding that we have as yet to be given good reasons to abandon the natural, substantivalist interpretation of current physics. (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.

In this paper, I examine the case that has been made for origin essentialism and find it wanting. I focus on the arguments of Nathan Salmon and Graeme Forbes. Like most origin essentialists, Salmon and Forbes have been concerned to respect the intuition that slight variation in the origin of an artifact or organism is possible. But, I argue, both of their arguments fail to respect this intuition. Salmon's argument depends on a sufficiency principle for cross-world identity, which should be (...) rejected, if - as Salmon concedes - a given artifact might have been originally made from slightly different material. Similarly, Forbes's argument succeeds only if essentially the same argument can be used to establish a claim that - by his own admission - is too strong, namely that no variation, however slight, in an organism's origin is possible. (shrink)

It is my aim in this paper to show that the contemporary assimilation of essence to modality is fundamentally misguided and that, as a consequence, the corresponding conception of metaphysics should be given up. It is not my view that the modal account fails to capture anything which might reasonably be called a concept of essence. My point, rather, is that the notion of essence which is of central importance to the metaphysics of identity is not to be understood in (...) modal terms or even to be regarded as extensionally equivalent to a modal notion. The one notion is, if I am right, a highly refined version of the other; it is like a sieve which performs a similar function but with a much finer mesh. (shrink)

Some philosophers respond to Leibniz’s “shift” argument against absolute space by appealing to antihaecceitism about possible worlds, using David Lewis’s counterpart theory. But separated from Lewis’s distinctive system, it is difficult to understand what this doctrine amounts to or how it bears on the Leibnizian argument. In fact, the best way of making sense of the relevant kind of antihaecceitism concedes the main point of the Leibnizian argument, pressing us to consider alternative spatiotemporal metaphysics.

David Lewis holds that a single possible world can provide more than one way things could be. But what are possible worlds good for if they come apart from ways things could be? We can make sense of this if we go in for a metaphysical understanding of what the world is. The world does not include everything that is the case—only the genuine facts. Understood this way, Lewis's “cheap haecceitism” amounts to a kind of metaphysical anti-haecceitism: it says there (...) aren't any genuine facts about individuals over and above their qualitative roles. (shrink)

This book critically examines some widespread views about the semantic phenomenon of reference and the cognitive phenomenon of singular thought. It begins with a defense of the view that neither is tied to a special relation of causal or epistemic acquaintance. It then challenges the alleged semantic rift between definite and indefinite descriptions on the one hand, and names and demonstratives on the other—a division that has been motivated in part by appeals to considerations of acquaintance. Drawing on recent work (...) in semantics, the book explores a more unified account of all four types of expression, according to which none of them paradigmatically fits the profile of a referential term. On the proposed framework, all four involve existential quantification but admit of uses that exhibit many of the traits associated with reference—a phenomenon that is due to the presence of what we call a ‘singular restriction’ on the existentially quantified domain. The book concludes by drawing out some implications of the proposed semantic picture for the traditional categories of reference and singular thought. (shrink)

Being Known is a response to a philosophical challenge which arises for every area of thought: to reconcile a plausible account of what is involved in the truth of statements in a given area with a credible account of how we can know those statements. Christopher Peacocke presents a framework for addressing the challenge, a framework which links both the theory of knowledge and the theory of truth with the theory of concept-possession.

Challenging, with several powerful arguments, some of our deepest beliefs about rationality, morality, and personal identity, Parfit claims that we have a false view about our own nature. It is often rational to act against our own best interersts, he argues, and most of us have moral views that are self-defeating. We often act wrongly, although we know there will be no one with serious grounds for complaint, and when we consider future generations it is very hard to avoid conclusions (...) that most of us will find very disturbing. (shrink)

In this paper, I examine the putative incompatibility of three theses: (1) Haecceitism, according to which some maximal possibilities differ solely in terms of the non-qualitative or de re possibilities they include; (2) Modal correspondence, according to which each maximal possibility is identical with a unique possible world; (3) Counterpart theory, according to which de re modality is analyzed in terms of counterpart relations between individuals. After showing how the modal realism defended by David Lewis resolves this incompatibility by rejecting (...) modal correspondence, I defend modal correspondence and develop an alternative strategy for reconciling these theses. Specifically, I examine Lewis’s arguments against non-qualitative counterpart theory and undermine them by developing a novel version of non-qualitative counterpart theory that appeals to a metaphysics of bare particulars. I then indicate how this version of non-qualitative counterpart theory accommodates both haecceitism and modal correspondence. (shrink)

Putative counterexamples to the Principle of Identity of Indiscernibles (PII) are notoriously inconclusive. I establish ground rules for debate in this area, offer a new response to such counterexamples for friends of the PII, but then argue that no response is entirely satisfactory. Finally, I undermine some positive arguments for PII.

Is the relation between properties and the causal powers they confer necessary, or contingent? Necessary, says Sydney Shoemaker, on pain of skepticism about the properties. Contingent, says David Lewis, swallowing the skeptical conclusion. I shall argue that Lewis is right about the metaphysics, but that Shoemaker and Lewis are wrong about the epistemology. Properties have intrinsic natures (quiddities), which we can know.

While many are impressed with the utility of possible worlds in linguistics and philosophy, few can accept the modal realism of David Lewis, who regards possible worlds as sui generis entities of a kind with the concrete world we inhabit.1 Not all uses of possible worlds require exotic ontology. Consider, for instance, the use of Kripke models to establish formal results in modal logic. These models contain sets often regarded for heuristic reasons as sets of “possible worlds”. But the “worlds” (...) in these sets can be anything at all; they can be numbers, or people, or sh. The set of worlds, together with the accessibility relation and the rest of the model, is used as a purely formal structure.2 One can even go beyond establishing results about formal systems and apply Kripke models to English, as Charles Chihara has recently argued.3 Chihara shows, for instance, how to use Kripke models (plus primitive modal notions) to give an account of validity for English modal sentences. In other cases worlds are not really needed at all. It is often vivid to give a counterexample thus: “There is a possible world in which P. Since your theory implies that in all worlds, not-P, your theory is wrong.” But the counterexample could just as easily be given using modal operators: “Possibly, P. Since your theory implies that it is necessary that not-P, your theory is wrong.”. (shrink)

The counterpart theorist has a problem: there is no obvious way to understand talk about actuality in terms of counterparts. Fara and Williamson have charged that this obstacle cannot be overcome. Here I defend the counterpart theorist by offering systematic interpretations of a quantified modal language that includes an actuality operator. Centrally, I disentangle the counterpart relation from a related notion, a ‘representation relation’. The relation of possible things to the actual things they represent is variable, and an adequate account (...) of modal language must keep track of the way it is systematically shifted by modal operators. I apply my account to resolve several puzzles about counterparts and actuality. In technical appendices, I prove some important logical results about this ‘representational’ counterpart system and its relationship to other modal systems. (shrink)

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

The distinction between qualitative properties like mass and shape and non-qualitative properties like being Napoleon and being next to Obama is important, but remains largely unexamined. After discussing its theoretical significance and cataloguing various kinds of non-qualitative properties, I survey several views about the nature of this distinction and argue that all proposed reductive analyses of this distinction are unsatisfactory. I then defend primitivism, according to which the distinction resists reductive analysis.

After sketching some aspects of truthmaker doctrines and "truthmaker projects", and canvassing some prima facie objections to the latter, I turn to an issue which might seem to involve confusion about the nature of character of truthmakers if such there be, viz for statements of identity and (specially) distinctness. The real issue here is versions of the Identity of Indiscernibles. I discuss ways of discriminating versions, which are almost certainly true but trivial, which almost certainly substantive but false, and explore (...) an interesting intermediate possibility which might if developed yield a plausibly true yet not-entirely-trivial version of the doctrine: it is equivalent to what I call "the Denial of Bare Distinctness". (shrink)

Structuralism and quidditism are competing views of the metaphysics of property individuation: structuralists claim that properties are individuated by their nomological roles; quidditists claim that they are individuated by something else. This paper (1) refutes what many see as the best reason to accept structuralism over quidditism and (2) offers a methodological argument in favor of a quidditism. The standard charge against quidditism is that it commits us to something ontologically otiose: intrinsic aspects of properties, so-called ‘quiddities’. Here I grant (...) that quiddities are ontologically otiose, but deny that quidditism requires them. According to a view I call ‘austere quidditism’, properties are individuated by bare numerical identity. I argue that, as far as ontological parsimony is concerned, austere quidditism and structuralism are on a par. But is austere quidditism a coherent alternative to structuralism? To see that it is, we must get clear on what exactly we mean by ‘property individuation’. What we discover is that structuralism is a counterpart theory for properties, and that austere quidditism is simply the rejection of counterpart theory. I conclude with a methodological argument to the effect that counterpart theory for properties ought to be rejected. This paper begins by situating the debate between structuralists and quidditists within the context of a debate over the epistemic limits of fundamental science. At the center of this debate is David Lewis’s posthumously published ‘Ramseyan Humility’ (2008). In the appendix I explain the precise role of austere quidditism in Lewis’s argument. (shrink)

Considerations upon the nature of properties and laws have led some philosophers to claim that the correct epistemic attitude with regards to the intrinsic properties of particulars is scepticism. I examine one particularly clear version of this line of argument, and contend that a serious form of scepticism is not established. However, I argue that the theories of properties and laws underlying the argument have unwanted metaphysical implications. These provide a stronger reason to jettison the analyses. I end by sketching (...) an alternative view that avoids these difficulties. -/- . (shrink)

The principle of the identity of indiscernibles holds that two individuals are the same individual if they have all the same properties. There are different forms of the principle, varying with what is allowed to count as a property. An individual has thisness if the weakest form of the principle does not apply to it. Abstract objects, places and times do not have thisness. Inanimate material objects probably do not. Animate beings, and the conscious events which involve them do have (...) thisness, and probably other events do as well. (shrink)

It is a commonsense thesis that unactualized possibilities are not parts of actuality. To keep his modal realism in line with this thesis, David Lewis employed his indexical account of the term “actual.” I argue that the addition of counterpart theory to Lewis’s modal realism undermines his strategy for respecting the commonsense thesis. The case made here also reveals a problem for Lewis’s attempt to avoid haecceitism.

This paper examines a doctrine which David Lewis has called 'Humean Supervenience' (hereafter 'HS'), and a problem which certain imaginary cases seem to generate for HS. They include rotating perfect spheres or discs, and flowing rivers, imagined as composed of matter which is perfectly homogeneous right down to the individual points. Before considering these examples, I shall introduce the doctrine they seem to challenge.

I address two related questions: first, what is the best theory of how objects have de re modal properties? Second, what is the best defence of essentialism given the variability of our modal intuitions? I critically discuss several theories of how objects have their de re modal properties and address the most threatening antiessentialist objection to essentialism: the variability of our modal intuitions. Drawing on linguistic treatments of vagueness and ambiguity, I show how essentialists can accommodate the variability of modal (...) intuitions while holding that objects have their modal properties independently of contexts. (shrink)

Thomas Hofweber argues that the thesis of direct reference is incompatible with physicalism, the claim that the nonphysical supervenes on the physical. According to Hofweber, direct reference implies that some physical objects have object-dependent properties, such as being Jones’s brother, which depend on particular objects for their existence and identity. Hofweber contends that if some physical objects have object-dependent properties, then Local-Local Supervenience (the physicalist doctrine on which he concentrates) fails. In this note, we argue that Hofweber has failed to (...) show that the possession by physical objects of object-dependent properties implies the falsity of Local-Local Supervenience. (shrink)

Anti-essentialism holds that no thing has any modal properties except relative to a conceptualization—for instance, relative to a description. One and the same thing might be essentially rational relative to the description “mathematician” but only accidentally rational relative to the description “bicyclist.” Anti-essentialism was dominant in pre-Kripkean days. The old description theory of names made room for anti-essentialism by reducing apparently true de re modal attributions to de dicto ones by way of the hidden description. We can follow Kripke in (...) giving up the description theory without thereby giving up anti-essentialism. Counterpart theory makes room for anti-essentialism by interpreting de re modal attributions by way of counterparts and allowing that different other-worldly objects count as a thing’s counterparts relative to different ways of thinking of the thing. One thing is essentially physical when thought of as a body but only accidentally physical when thought of as a person. One thing has its shape essentially when thought of as a statue but only accidentally when thought of as a lump of clay. The metaphysical meat of counterpart theory is that it allows for anti-essentialism. (shrink)