Counterpart Theory

William of Ockham seems to have endorsed the view (i) that a whole is its parts, (ii) that some things are such that whether they together compose a whole is contingent, and (iii) that parts are ontologically prior to the whole they compose. Ockhamist Composition as Identity is the conjunction of these three claims. It seems doubly absurd since Leibniz’s Law arguments can be run against both the conjunction of (i) and (ii) and that of (i) and (iii). In this (...) article, I appeal to recent developments in counterpart theory to block these arguments and adequately interpret the Ockhamist version of the view that composition is identity. (shrink)

Privileged-perspective realism (PPR) is a version of metaphysical realism that takes certain irreducibly perspectival facts to be partly constitutive of reality. PPR asserts that there is a single metaphysically privileged standpoint from which these perspectival facts obtain. This chapter discusses several views that fall under the category of privileged-perspective realism. These include presentism, which is PPR about tensed facts, and non-multiverse interpretations of quantum mechanics, which the chapter argues, constitute PPR about world-indexed facts. Using the framework of the bird perspective (...) and the frog perspective, it argues that PPR views methodologically treat the frog perspective as metaphysically primary. This chapter considers case studies of metaphysical interpretations of special relativity and quantum mechanics in order to demonstrate that such motivations for PPR are non-naturalistic. Further, it considers psychological factors that motivate the appeal of PPR views and offers naturalistic explanations of why we should not expect them to produce an adequate metaphysics of science. (shrink)

Expressions typically thought to be rigid designators can refer to distinct individuals in the consequents of counterfactuals. This occurs in counteridenticals, such as “If I were you, I would arrest me”, as well as more ordinary counterfactuals with clearly possible antecedents, like “If I were a police officer, I would arrest me”. I argue that in response we should drop rigidity and deal with de re modal predication using something more flexible, such as counterpart theory.

In a recent paper, Brian Rabern suggests a semantics for languages with two kinds of modality, standard Kripkean metaphysical modality as well as epistemic modality. This semantics presents an alternative to two-dimensionalism, which was developed in the last decades. Both Rabern’s semantics and two-dimensionalism are subject to a puzzle that Chalmers and Rabern (2014) call the nesting problem. I will investigate how Rabern’s semantics answers this puzzle.

We propose and investigate an Analogy Principle in the context of Unary Inductive Logic based on a notion of support by structural similarity which is often employed to motivate scientific conjectures.

David Lewis's modal realism claims that nothing can exist in more than one world or time, and that statements about how something would have been are to be analysed in terms of its counterpart. I first explain why the counterpart relation depends on de re modal statements in an intensional language, so that intuitive properties of similarity relations cannot be used to show that the counterpart relation is not an equivalence relation. I then look at test sentences in natural language, (...) and show that none of them provide compelling evidence that a counterpart semantics is needed. (shrink)

This book defends a radical new theory of contingency as a physical phenomenon. Drawing on the many-worlds approach, it argues that quantum theories are best understood as telling us about the space of genuine possibilities, rather than as telling us solely about actuality.

An intuitive objection to modal realism is that merely possible worlds and their inhabitants seem to be irrelevant to an analysis of modality. Kripke originally phrased the objection in terms of being concerned about one’s modal properties without being concerned about the properties one’s other-worldly counterparts have. The author assesses this objection in a variety of forms, and then provides his own formulation that does not beg the question against the modal realist. Finally, the author considers two potential answers to (...) the objection so understood and concludes that only one of them has a chance of succeeding. (shrink)

Bundle theories identify material objects with bundles of properties. On the traditional approach, these are the properties possessed by that material object. That view faces a deep problem: it seems to say that all of an object’s properties are essential to it. Essential bundle theory attempts to overcome this objection, by taking the bundle as a specification of the object’s essential properties only. In this paper, I show that essential bundle theory faces a variant of the objection. To avoid the (...) problem, the theory must accept the contingency of identity. I show how this can be achieved in a coherent and well-motivated way, a way that isn’t available to traditional bundle theories. (shrink)

A counteridentical is a counterfactual with an identity statement in the antecedent. While counteridenticals generally seem non-trivial, most semantic theories for counterfactuals, when combined with the necessity of identity and distinctness, attribute vacuous truth conditions to such counterfactuals. In light of this, one could try to save the orthodox theories either by appealing to pragmatics or by denying that the antecedents of alleged counteridenticals really contain identity claims. Or one could reject the orthodox theory of counterfactuals in favor of a (...) hyperintensional semantics that accommodates non-trivial counterpossibles. In this paper, I argue that none of these approaches can account for all the peculiar features of counteridenticals. Instead, I propose a modified version of Lewis’s counterpart theory, which rejects the necessity of identity, and show that it can explain all the peculiar features of counteridenticals in a satisfactory way. I conclude by defending the plausibility of contingent identity from objections. (shrink)

Quine insisted that the satisfaction of an open modalised formula by an object depends on how that object is described. Kripke’s "objectual" interpretation of quantified modal logic, whereby variables are rigid, is commonly thought to avoid these Quinean worries. Yet there remain residual Quinean worries in the epistemic case. Theorists have recently been toying with assignment-shifting treatments of epistemic contexts. On such views an epistemic operator ends up binding all the variables in its scope. One might worry that this yields (...) the undesirable result that any attempt to "quantify in" to an epistemic environment is blocked. But a famous alternative to Kripke's semantics, namely Lewis' counterpart semantics, also faces this worry, since it also treats the boxes and diamonds as assignment-shifting devices. As I'll demonstrate, the mere fact that a variable is bound is no obstacle to binding it. This provides a helpful lesson for those modelling de re epistemic contexts with assignment sensitivity, and perhaps leads the way toward the proper treatment of binding in both metaphysical and epistemic contexts: Kripke for metaphysical modality, Lewis for epistemic modality. (shrink)

It is shown that counterpart theory and the duplication account of intrinsicality —two key pieces of the Lewisian package—are incompatible. In particular, the duplication account yields the result that certain intuitively extrinsic modal properties are intrinsic. Along the way I consider a potentially more general worry concerning certain existential closures of internal relations. One conclusion is that, unless the Lewisian provides an adequate alternative to the duplication account, the reductive nature of their total theory is in jeopardy.

Relativized Metaphysical Modality (RMM: Murray and Wilson, 'Relativized metaphysical modality', Oxford Studies in Metaphysics, 2012; Murray, Perspectives on Modal Metaphysics, 2017) exploits 'two-dimensionalist' resources to metaphysical, rather than epistemological, ends: the second dimension offers perspective-dependence without contingency, diverting attacks on 'Classical' analyses of modals (in effect, analyses validating S5 and the Barcan Formulae). Here, we extend the RMM program in two directions. First, we harvest resources for RMM from Lewis's 1980 'Context--Index' (CI) framework: (a) the ban in CI on binding (...) into context-arguments (akin to Kaplan's 'monstrosity' ban) projects a bright line between perspective-dependence and contingency; and (b) CI-postulated connections among meaning, content, truth, argument-structure, context, and modality collectively generate a 'Generalized Humphrey Problem' for any non-Classical analysis (examples covered include appeals to accessibility, contingent domains, and counterpart relations). Second, we sharpen the tools of RMM-based metaphysical analysis, and extend their domain of coverage across familiar anomalies for Classical modals: we revisit earlier RMM-based bulwarks for S5 (against 'Chisholm's Paradox' for moderate flexibility of essence, and nomological necessitarianism); and we now similarly shore up the Barcan Formulae (against the apparent contingency of existence and nonexistence). (shrink)

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)

In her stimulating article, Catherine Wilson considers the moment of worlds-making in Leibniz’s philosophy. She raises the following question: “How do possible substances give rise to possible worlds?“ and observes that the moment of world-making is as puzzling as it is interesting. In section 2 of her article, Wilson considers two approaches to the question. According to the first, possible individuals logically precede possible worlds and possible worlds are constituted either by combinations of possible individuals or by mechanically checking the (...) compossibility relations among them. This approach assumes that possible individuals are given and complete and that worlds result from their various conjunctions. On this approach, a world is a set of compossible individuals, i.e., a set of complete individuals whose co-existence is possible. (shrink)

The problem of identity across possible worlds is raised with the following questions: What does it mean to say of something in one possible world that it is identical with something in another possible world? How are we to decide whether an individual in one possible world is identical with an individual in another?1 Because the questions concern meaning and verification, it appears to be the case that they presuppose that there are one or more sentences whose meaning and method (...) of verification are in need of explanation. However, although it has been generally presumed to be easy, it turns out to be very difficult to produce a sentence that enables us to formulate the problem and that is not merely supposed to say, but really does say, of an individual in one world and of an individual in another world that the first individual is identical with the second. (shrink)

Surely, it is possible that you believe falsely about this-or-that modal matter. In light of the various ways the world could be arranged, it is plausible thatthere is a nearby possible world, which would be almost identical to the actual world, if it were actualized, where you and your modal counterpart disagree over modal belief p. You might be tempted to think that your modal belief is true, while hers is not. It is not clear why this is so; after (...) all, you would each have the same evidence, cognitive abilities etc., if you were both actualized. This point generalizes to all of your modal beliefs, this seems to strongly imply that the probability that you have true modal beliefs appears inscrutable. Thus, you have some reason to withhold belief, on modal matters. (shrink)

Suppose that reality consists of parallel universes of every variety imaginable. No path through space and time leads from one to another, and each universe is causally isolated from the rest. Some physicists believe a ‘multiverse’ hypothesis not terribly distant from this one simplifies quantum mechanics and provides an elegant explanation of why our universe has its particular laws. Suppose as science advances we come to accept the multiverse hypothesis, so construed.

Jim Stone argues that one cannot combine three-dimensionalism with counterpart theory. This paper argues to the contrary.

It is widely agreed that properties play causal roles: they capture the causal powers of things. But do properties have their causal roles essentially? David Lewis did not think so. He adhered to the doctrine of quidditism, namely the doctrine that the identity of properties is primitive and that they can trade their causal roles. Quidditism is controversial. But Lewis did not see why he should want to reject it. He knew that he could avoid quidditism on the cheap by (...) treating individuals and properties alike in rejecting transworld multilocation of properties and endorsing a counterpart theory for properties. But he did not see why he should want to do so. In this article, I argue that Lewis should have wanted to endorse a counterpart theory for properties in order to reject quidditism. My argument concerns resemblance relations among properties. Another constitutive role of properties is that they capture objective resemblances between their instances. The premises of my argument are intuitive claims about resemblances among some properties that Lewis held on Humean grounds. (shrink)

I call anti-resemblism the thesis that independently of any contextual specification there is no determinate fact of the matter about the comparative overall similarity of things. Anti-resemblism plays crucial roles in the philosophy of David Lewis. For instance, Lewis has argued that his counterpart theory is anti-essentialist on the grounds that counterpart relations are relations of comparative overall similarity and that anti-resemblism is true. After Lewis committed himself to a form of realism about natural properties he maintained that anti-resemblism is (...) true about the relations of overall similarity that enter his counterpart theory and his analysis of counterfactuals. However, in this article I argue that Lewis’s account of degrees of naturalness for properties combined with his modal realism entails that anti-resemblism is false. The Lewisian must amend Lewis’s system if she aims to benefit from the alleged virtues of anti-resemblism. I consider two ways of amending it, neither of which is a free lunch. (shrink)

A number of philosophers have recently found it congenial to talk in terms of grounding. Grounding discourse features grounding sentences that are answers to questions about what grounds what. The goal of this article is to explore and defend a counterpart-theoretic interpretation of grounding discourse. We are familiar with David Lewis's applications of the method of counterpart theory to de re modal discourse. Counterpart-theoretic interpretations of de re modal idioms and grounding sentences share similar motivations, mechanisms, and applications. I shall (...) explain my motivations and describe two applications of a counterpart theory for grounding discourse. But, in this article, my main focus is on counterpart-theoretic mechanisms. (shrink)

Problems about the accidental properties of properties motivate us--force us, I think--not to identify properties with the sets of their instances. If we identify them instead with functions from worlds to extensions, we get a theory of properties that is neutral with respect to disputes over counterpart theory, and we avoid a problem for Lewis's theory of events. Similar problems about the temporary properties of properties motivate us--though this time they probably don't force us--to give up this theory as well, (...) and to identify properties with functions from world, time pairs to extensions. Again, the replacement theory is neutral with respect to a metaphysical dispute that the old theory (arguably) forces us to take a stand on--the dispute over whether objects have temporal parts. It also allows us to give a smoother semantics for predication, to better accommodate our intuitions about which objects temporary properties are properties of, and to make temporally self-locating beliefs genuinely self -locating. (shrink)

It follows from David Lewis's counterpart-theoretic analysis of modality and his counterfactual theory of causation that causal claims are relativized to a set of counterpart relations. Call this Shlewis's view. I show how Shlewis's view can provide attractively unified solutions to similar modal and causal puzzles. I then argue that Shlewis's view is better motivated, by his own lights, than the view Lewis actually held, and also better motivated than a similar approach which relativizes causal claims to sets of ‘contrast (...) events’. (shrink)

The standard conception of God is that of a necessary being. On a possible worlds semantics, this entails that God exists at every possible world. According to the modal realist account of David Lewis, possible worlds are understood to be real, concrete worlds—no different in kind from the actual world. Some have argued that Lewis’s view is incompatible with classical theism (e.g., Sheehy, 2006). More recently, Ross Cameron (2009) has defended the thesis that Lewisian modal realism and classical theism are (...) in fact compatible. I argue that this is not the case. Modal realism, I argue, is equipped to accommodate necessary beings in only one of three ways: (1) By way of counterpart theory, or (2) by way of a special case of trans-world identity for causally inert necessary beings (e.g., pure sets), or else (3) causally potent ones which lack accidental intrinsic properties. However, each of these three options entails unacceptable consequences—(1) and (2) are incompatible with theism, and (3) is incompatible with modal realism. I conclude that (at least) one of these views is false. (shrink)

Two criteria for rigid designation are distinguished; one according to which 'e' is rigid if 'e might not have been e' is false and the other according to which 'e' is rigid if it designates the same thing in all possible worlds in which it designates anything at all. Such criteria are not equivalent since 'x could not but be f' is not entailed by 'nothing other than x could be f'. I illustrate the latter lack of entailment.

Non-Identity arguments have a pervasive but sometimes counter-intuitive grip on certain key areas in ethics. As a result, there has been limited success in supporting the alternative view that our choices concerning future generations can be considered harmful on any sort of person-affecting principle. However, as the Non-Identity Problem relies overtly on certain metaphysical assumptions, plausible alternatives to these foundations can substantially undermine the Non-Identity argument itself. In this paper, I show how the pervasive force and nature of Non-Identity arguments (...) rely upon a specific adoption of a theory of modality and identity and how adopting an alternative account of modality can be used to reject many conclusions formed through Non-Identity type arguments. By using Lewis’s counterpart-theoretic account to understand ways we might have been, I outline the basis of a modal account of harm that incorporates a person-affecting aspect. This, in turn, has significant implications for ethical decision-making in areas such as reproductive choice and the welfare of future generations. (shrink)

According to the Truthmaker Principle: every truth has a truthmaker. Attempts to come to grips with the Truthmaker Principle played a prominent role in Lewis’s metaphysical writings over the last fifteen years of his career. Although Lewis agreed that the truth of propositions must somehow be ontologically grounded, the Truthmaker Principle was too strong: it conflicted with two of Lewis’s most fundamental metaphysical assumptions, the uniqueness of composition and the Humean denial of necessary connections. Lewis endorsed instead a weaker principle: (...) Truth Supervenes on Being. But towards the end of his career, he changed course, noting that his critique of the Truthmaker Principle rested on essentialist assumptions that he, as a counterpart theorist, does not accept. Once freed from those assumptions, a counterpart theorist can accept the Truthmaker Principle after all without buying into unmereological composition and mysterious necessary connections. (shrink)

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