How should we account for the extraordinary regularity in the world? Humeans and Non-Humeans sharply disagree. According to Non-Humeans, the world behaves in an extraordinarily regular way because of certain necessary connections in nature. However, Humeans have thought that Non-Humean views are metaphysically objectionable. In particular, there are two general metaphysical principles that Humeans have found attractive that are incompatible with all existing versions of Non-Humeanism. My goal in this paper is to develop a novel version of Non-Humeanism that is (...) consistent with (and even entails) both of these general metaphysical principles. By endorsing such a view, one can have the explanatory benefits of Non-Humeanism while at the same time avoiding two of the major metaphysical objections towards Non-Humeanism. (shrink)

Relativity theory is often said to support something called ‘the four-dimensional view of reality’. But there are at least three different views that sometimes go by this name. One is ‘spacetime unitism’, according to which there is a spacetime manifold, and if there are such things as points of space or instants of time, these are just spacetime regions of different sorts: thus space and time are not separate manifolds. A second is the B-theory of time, according to which the (...) past, present, and future are all equally real and there is nothing metaphysically special about the present. A third is perdurantism, according to which persisting material objects are made up of different temporal parts located at different times. We sketch routes from relativity to unitism and to the B-theory. We then discuss some routes to perdurantism, via the B-theory and via unitism. (shrink)

Many philosophers have thought that our folk, or pre-reflective, view of persistence is one on which objects endure. This assumption not only plays a role in disputes about the nature of persistence itself, but is also put to use in several other areas of metaphysics, including debates about the nature of change and temporal passage. In this paper, we empirically test three broad claims. First, that most people (i.e. most non-philosophers) believe that, and it seems to them as though, objects (...) persist by enduring rather than perduring. Second, that most people have a view of change on which enduring but not perduring objects count as changing. Third, that one reason why the folk represent time as dynamical is because it seems to them, and they believe that, they endure through time. We found no evidence to support these claims. While there are certainly plenty of ‘folk’ endurantists in the population we tested, there are also plenty of ‘folk’ perdurantists. We did not find robust evidence that a majority of people believed that, or it seemed to them as though, objects endure rather than perdure. We conclude that many arguments in favour of endurantism that appeal to folk beliefs about, or experiences of, persisting objects and change rest on views about those beliefs and experiences that are empirically unsupported. There is no evidence to suggest that endurantism is the folk friendly view of persistence, and so we should stop treating it as such without argument. (shrink)

Is the objective passage of time compatible with relativistic physics? There are two easy routes to an affirmative answer: (1) provide a deflationary analysis of passage compatible with the block universe, or (2) argue that a privileged global present is compatible with relativity. (1) does not take passage seriously. (2) does not take relativity seriously. This paper is concerned with the viability of views that seek to take both passage and relativity seriously. The investigation proceeds by considering how traditional A-theoretic (...) conceptions of passage might be generalized to relativistic space-times without incorporating a privileged global present. I argue that the most promising position marries the idea that open possibilities for the future are settled as time passes with a ‘non-standard’ interpretation of the relevant formal models. (shrink)

The central aim of this paper is to use a particular view about how the laws of nature govern the evolution of our universe in order to develop and evaluate the two main competing options in the metaphysics of persistence, namely endurantism and perdurantism. We begin by motivating the view that our laws of nature dictate not only qualitative facts about the future, but also which objects will instantiate which qualitative properties. We then show that both traditional doctrines in the (...) metaphysics of persistence must take on surprising further commitments in order to vindicate our universe being law-governed in this strong sense. For example, we argue that endurantists should adopt a particular version of monism, and that perdurantists should adopt a qualitativist doctrine that dispenses with all individuals at the fundamental level. (shrink)

The possibility of multi-location—of one entity having more than one exact location—is required by several metaphysical theories such as the immanentist theory of universals and three-dimensionalism about persistence. One of the most pressing challenges for multi-location theorists is that of making sense of exact location—in that extant definitions of exact location entail a principle called ‘functionality’, according to which nothing can have more than one exact location. Recently in a number of promising papers, Antony Eagle has proposed and defended a (...) definition of exact location in terms of weak location that does not entail functionality. This paper provides the first thorough assessment of Eagle’s proposal. In particular, we argue that it cannot account for the location of immanent universals, the multi-location of mereologically changing three-dimensional objects, the multi-location of mereologically complex objects, and that it makes extended simples impossible. (shrink)

The notion of multiple location plays an important role in the characterization of endurantism. Several authors have recently offered cases intended to demonstrate the incoherence of multiple location. I argue that these cases do not succeed in making multiple location problematic. Along the way, several crucial issues about multiple location and its use by endurantists are clarified.

Timothy Williamson thinks that every object is a necessary, eternal existent. In defense of his view, Williamson appeals primarily to considerations from modal and tense logic. While I am uncertain about his modal claims, I think there are good metaphysical reasons to believe permanentism: the principle that everything always exists. B-theorists of time and change have long denied that objects change with respect to unqualified existence. But aside from Williamson, nearly all A-theorists defend temporaryism: the principle that there are temporary (...) existents. I think A-theorists are better off without this added commitment, but I will not argue for that in any great detail here. Instead, I will contend that a very tempting A-theoretic argument for temporaryism is unsound. In the first half of the paper, I will develop the Moorean “common sense” argument for temporaryism and dispute its central premise, namely that temporaryism is a valid generalization from highly plausible beliefs about change. I will argue that given the pervasive vagueness in our ordinary beliefs about change and the background commitments of all A-theories, no party can claim to be the common sense view because no party can accommodate most of our common sense beliefs about change in existence. In the second half of the paper, I will propose a permanentist A-theory that explains all change over time as a species of property change. I call it the minimal A-theory, since it dispenses with the change in existence assumption. As we'll see, the permanentist alternative performs well enough in explaining our ordinary beliefs about change, and it has better prospects for answering some objections commonly levied against A-theories. (shrink)

Recently, many philosophers have been interested in using locative relations to clarify and pursue debates in the metaphysics of material objects. Most begin with the relation of exact location. But what if we begin instead with the relation known as weak location – the relation an object x bears to any region not completely bereft of x? I explore some of the consequences of pursuing this route for issues including coincidence, extended simples, and endurance, with an eye to evaluating the (...) prospects for taking weak location as our fundamental locative relation. (shrink)

Recently, Cody Gilmore has deployed an ingenious case involving backwards time travel to highlight an apparent conflict between the theory that objects persist by perduring, and the thesis that wholly coincident objects are impossible. However, careful attention to the concepts of location and parthood that Gilmore’s cases involve shows that the perdurantist faces no genuine objection from these cases, and that the perdurantist has a number of plausible and dialectically appropriate ways to avoid the supposed conflict.

One of the central debates in contemporary metaphysics has been the debate between endurantism and perdurantism about persistence. In this paper I argue that much of this debate has been misconstrued: most of the arguments in the debate crucially rely on theses which are strictly orthogonal to the endurantism/perdurantism debate. To show this, I note that the arguments in the endurantism/perdurantism debate typically take the following form: one presents a challenge that endurantists allegedly have some trouble addressing, and to which (...) perdurantism apparently has a straightforward response. I argue, however, that in each case, there are versions of endurantism that can offer precisely the same response to the challenge, and thus the ability to provide this particular solution does not directly tell in favour of one the two views. In §1, I elaborate two views which will be particularly prominent in the discussion: liberal endurantism and restrictive perdurantism. In §2–6 I discuss in turn the central pro-perdurantism arguments: the argument from anthropocentricism, the argument from vagueness, the argument from recombination, the argument from temporary intrinsics, and the argument from coincidence. In §7–8, I discuss the main pro-endurantism arguments: the arguments from motion, and the argument from permanent coincidence. Finally, in §9, I discuss what conclusion can be drawn from this discussion. (shrink)

This article discusses two arguments in favor of perdurance. The first is Sider’s argument from vagueness, “one of the most powerful” in favor of perdurantism. I make the observation that endurantists have principled grounds to claim that the argument is unsound, at least if endurance is formulated in locative rather than mereological terms. Having made this observation, I use it to emphasize a somewhat neglected difference between endurantists and perdurantists with respect to their views on material objects. These views, in (...) the case of endurantists, lead to a further, less than conclusive but nevertheless interesting argument against endurantism—the anti-fundamentality argument—which I discuss and tentatively endorse. That argument posits that endurantists must take location to be a fundamental relation, and that this has as a consequence the metaphysical possibility of some rather unwelcome scenarios. Perdurantists may avoid this consequence by denying that location is fundamental, perhaps by embracing supersubstantivalism. (shrink)

One of the most intuitive views about the metaphysics of laws of nature is Tim Maudlin's idea of a Fundamental Law of Temporal Evolution. So-called FLOTEs are primitive elements of the universe that produce later states from earlier states. While FLOTEs are at home in traditional Newtonian and non-relativistic quantum mechanical theories (not to mention our pre-theoretic conception of the world), I consider here whether they can be made to work with relativity. In particular, shifting to relativistic spacetimes poses two (...) threats to FLOTEs. First, the lack of a privileged spacelike hypersurface in relativistic spacetime makes it unclear how to understand what produces what. A survey of several conceptions of the nomic production relation compatible with relativity reveals all of them to be lacking. Second, relativity motivates a four-dimensional block universe conception of time, according to which all events that will ever occur already exist. On such a view, it's unclear what work there is to be done by FLOTEs. I consider how a proponent of FLOTEs might respond, but conclude that these combined threats seriously undermine the prospects of a productive conception of laws. In short, if spacetime is relativistic, laws are not productive. (shrink)

According to one of the more popular endurantist packages on the market, a package I will call multilocational endurantism, enduring objects are exactly located at multiple instantaneous regions of spacetime. However, for all we know, the world might turn out to be spatiotemporally gunky and spatiotemporal gunk entails that this package is false. The goal of this paper is to sketch a view which retains the spirit of multilocational endurantism while also recognizing the possibility of certain types of objects which (...) endure through gunk. (shrink)

This paper investigates the use of theories of mechanics to provide answers to questions in the metaphysics of spatial location and persistence. Investigating spatial location, I find that in classical physics bodies pertend the region of space at which they are exactly located, while a quantum system spans a region at which it is exactly located. Following this analysis, I present a ‘no-go’ result which shows that quantum mechanics restricts the available options for locational persistence theories in an interesting way: (...) it demonstrates that the spatiotemporal path of a persisting thing is discrete in time. This leads to unpalatable consequences for both perdurantists and endurantists. In particular, I argue that Butterfield's ‘anti-pointilliste’ perdurantism is ruled out, and show that endurantists relying on immanent causation run into trouble. I conclude by suggesting the revival of Whitehead's alternative mode of persistence called ‘reiteration.’. (shrink)

This book defends a relational theory of the passage of time. The realist view of passage developed in this book differs from the robust, substantivalist position. According to relationism, passage is nothing over and above the succession of events, one thing coming after another. Causally related events are temporally arranged as they happen one after another along observers’ worldlines. There is no unique global passage but a multiplicity of local passages of time. After setting out this positive argument for relationism, (...) the author deals with five common objections to it: (a) triviality of deflationary passage, (b) a-directionality of passage, (c) the impossibility of experiencing passage, (d) fictionalism about passage, and (e) the incompatibility of passage with perduring objects. (shrink)

How is the debate between endurantism and perdurantism affected by the transition from pre-relativistic spacetimes to relativistic ones? After suggesting that the endurance vs. perdurance distinction may run together a pair of cross-cutting distinctions, I discuss two recent attempts to show that the transition in question does serious damage to endurantism.

Material objects extend through space by having different spatial parts in different places. But how do they persist through time? According to some philosophers, things have temporal parts as well as spatial parts: accepting this is supposed to help us solve a whole bunch of metaphysical problems, and keep our philosophy in line with modern physics. Other philosophers disagree, arguing that neither metaphysics nor physics give us good reason to believe in temporal parts.

An introduction to the theories of endurantism and perdurantism, and persistence more broadly.

Endurantism, the view that material objects are wholly present at each moment of their careers, is under threat from supersubstantivalism, the view that material objects are identical to spacetime regions. I discuss three compromise positions. They are alike in that they all take material objects to be composed of spacetime points or regions without being identical to any such point or region. They differ in whether they permit multilocation and in whether they generate cases of mereologically coincident entities.

In this paper, I focus on three issues intertwined in current debates between endurantists and perdurantists—(i) the dimension of persisting objects, (ii) whether persisting objects have timeless, or only time-relative, parts, and (iii) whether persisting objects have proper temporal parts. I argue that one standard endurantist position on the first issue is compatible with standard perdurantist positions on parthood and temporal parts. I further argue that different accounts of persistence depend on the claims about objects' dimensions and not on the (...) auxiliary claims about parthood and temporal parts. (shrink)

In “Tense and Reality”, Kit Fine () proposed a novel way to think about realism about tense in the metaphysics of time. In particular, he explored two non-standard forms of realism about tense, arguing that they are to be preferred over standard forms of realism. In the process of defending his own preferred view, fragmentalism, he proposed a fragmentalist interpretation of the special theory of relativity, which will be our focus in this paper. After presenting Fine's position, we will raise (...) a problem for his fragmentalist interpretation of STR. We will argue that Fine's view is in tension with the proper explanation of why various facts obtain. We will then consider whether similar considerations also speak against fragmentalism in domains other than STR, notably fragmentalism about tense. (shrink)

Philosophers often state that the persistence of objects in vision is experienced differently than the persistence of sounds in audition. This difference is expressed by using metaphors from the metaphysical endurantism/perdurantism debate. For instance, it is claimed that only sounds are perceived as “temporally extended”. The paper investigates whether it is justified to characterize visually experienced objects and auditorily experienced sounds as different types of entities: endurants and perdurants respectively. This issue is analyzed from the perspective of major specifications of (...) the endurance/perdurance distinction connected, inter alia, with the notions of temporal parts and temporal localization. It is argued that it is unjustified to characterize visually experienced objects and auditorily experienced sounds as different types of entities in respect of how they persist. On the other hand, the apparent difference in the way of persisting can be explained by the presence of contingent differences between typical visual and auditory experiences. (shrink)

Ned Markosian has recently defended a new theory of composition, which he calls regionalism : some material objects xx compose something if and only if there is a material object located at the fusion of the locations of xx. Markosian argues that regionalism follows from what he calls the subregion theory of parthood. Korman and Carmichael agree. We provide countermodels to show that regionalism does not follow from, even together with fourteen potentially implicit background principles. We then show that regionalism (...) does follow from five of those background principles together with and two additional principles connecting parthood and location, which we call and. While the additional principles are not uncontroversial, our conjecture is that many will find them attractive. We conclude by mentioning that fills a previously unnoticed gap in the formal theory of location presented in Parsons. (shrink)

This paper argues that recent arguments to the effect that the debate between presentism and eternalism lacks any metaphysical substance ultimately fail, although important lessons can be gleaned from them in how to formulate a non-vacuous version of presentism. It suggests that presentism can best be characterized in the context of spacetime theories. The resulting position is an ersatzist version of presentism that admits merely non-present entities as abstracta deprived of physical existence. Ersatzist presentism both escapes the charges of triviality (...) and promises to offer a route to solving the grounding problem which befalls its more traditional cousins. (shrink)

This paper discusses how the possibility of multi-located entities can resolve problems both with the Trinity and with the existence of souls.

Richard Arthur and I proposed that the present in Minkowski spacetime should be thought of as a small causal diamond. That is, given two timelike separated events p and q, with p earlier than q, they suggested that the present is the set I+ ∩ I-. Mauro Dorato presents three criticisms of this proposal. I rebut all three and then offer two more plausible criticisms of the Arthur/Savitt proposal. I argue that these criticisms also fail.

This is a very introductory introduction to some ways in which the special and general theories of relativity may bear upon metaphysical questions about the nature of time and space, and the persistence of objects.

Presentists have typically argued that the Block View is incapable of explaining our experience of time. In this paper I argue that the phenomenology of our experience of time is, on the contrary, against presentism. My argument is based on a dilemma: presentists must either assume that the metaphysical present has no temporal extension, or that it is temporally extended. The former horn leads to phenomenological problems. The latter renders presentism metaphysically incoherent, unless one posits a discrete present that, however, (...) suffers from the same difficulties that the instantaneous present is prone to. After introducing the main phenomenological models of our experience of time that are discussed in the literature, I show that none of them favors presentism. I conclude by arguing that if even the phenomenology of time sides against presentism, the latter metaphysical theory has no scientific evidence in its favor and ought to be dropped. (shrink)

Beliefs come in different strengths. What are the norms that govern these strengths of belief? Let an agent's belief function at a particular time be the function that assigns, to each of the propositions about which she has an opinion, the strength of her belief in that proposition at that time. Traditionally, philosophers have claimed that an agent's belief function at any time ought to be a probability function (Probabilism), and that she ought to update her belief function upon obtaining (...) new evidence by conditionalizing on that evidence (Conditionalization). Until recently, the central arguments for these claims have been pragmatic. But these putative justifications fail to identify what is epistemically irrational about violating Probabilism or Conditionalization. A new approach, which I will call epistemic utility theory, attempts to remedy this. It treats beliefs as epistemic acts; and it appeals to the notion of an epistemic utility function, which measures of how epistemically valuable a particular belief function is for a particular way the world might be. It then formulates fundamental epistemic norms that are analogous to the fundamental practical norms that underlie decision theory. I survey the results obtained so far in this young research project, and present a sustained critique of certain assumptions that have been made by a number of philosophers working in this area. (shrink)

A-theorists think there is a fundamental difference between the present and other times. This concern shows up in what kinds of properties they take to be instantiated, what objects they think exist and how they formalize their views. Nearly every contemporary A-theorist assumes that her metaphysics requires a tense logic – a logic with operators like and. In this paper, I show that there is at least one viable A-theory that does not require a logic with tense operators. And I (...) will argue that three common indispensability arguments for tense operators are unsound. (shrink)

According to a well known, yet controversial metaphysical thesis, Composition is Identity. Recently, Kris McDaniel has articulated and defended a related—and arguably more controversial—thesis, one he calls Parthood is Identity (PI). Roughly the view has it that a whole is, strictly and literally, identical to each of its parts considered individually. At first sight, the view seems rather implausible. However, McDaniel’s formulation and defense are worthy of a serious discussion. In this paper I put forth such a discussion. The result (...) is what we should have expected all along: PI is not only implausible, but arguably false. (shrink)

Philosophers of science have often favoured reductive approaches to how-possibly explanation. This article identifies three alternative conceptions making how-possibly explanation an interesting phenomenon in its own right. The first variety approaches “how possibly X?” by showing that X is not epistemically impossible. This can sometimes be achieved by removing misunderstandings concerning the implications of one’s current belief system but involves characteristically a modification of this belief system so that acceptance of X does not result in contradiction. The second variety offers (...) a potential how-explanation of X. It is usually followed by a range of further potential how-explanations of the same phenomenon. In recent literature the factual claims implied by the second variety have been downplayed whereas the heuristic role of mapping the space of conceptual possibilities has been emphasized. I will focus especially on this truth-bracketing sense of potentiality when looking closer at the second variety in the paper. The third variety has attracted less interest. It presents a partial how-explanation of X. Typically it aims to establish the existence of a mechanism by which X could be and was generated. The third conception stands out as the natural alternative for the advocate of ontic how-possibly explanations. This article transfers Salmon’s view that explanation-concepts can be broadly divided into epistemic, modal, and ontic to the context of how-possibly explanations. Moreover, it is argued that each of the three above-mentioned varieties of how-possibly explanation occurs in science. To recognize this may be especially relevant for philosophers. We are often misled by the promises of various why-explanation accounts, and seem to have forgotten nearly everything about the diversity of how-possibly explanations. (shrink)

Much recent discussion in social epistemology has focussed on the question of whether peers can rationally sustain a disagreement. A growing number of social epistemologists hold that the answer is negative. We point to considerations from the history of science that favor rather the opposite answer. However, we also explain how the other position can appear intuitively attractive.

Roughly speaking, perdurantism is the view that ordinary objects persist through time by having temporal parts, whilst endurantism is the view that they persist by being wholly present at different times. (Speaking less roughly will be important later.) It is often thought that perdurantists have an advantage over endurantists when dealing with objects which appear to coincide temporarily: lumps, statues, cats, tail-complements, bisected brains, repaired ships, and the like. Some cases – personal fission, for example – seem to involve temporary (...) coincidence between objects of the same kind. Other cases – a cat and its flesh, a statue and its lump – seem to involve objects of different kinds. (shrink)

The paper presents a thorough exploration of the problem of persistence in a relativistic context. Using formal methods such as mereology, formal theories of location and the so called intrinsic formulation of special relativity we provide a new, more rigorous and more comprehensive taxonomy of persisting entities. This new taxonomy differs significantly from the ones that are present in the recent literature.

According to the environment-induced approach to decoherence, the split of the Universe into the degrees of freedom which are of direct interest to the observer and the remaining degrees of freedom is absolutely essential for decoherence. However, the EID approach offers no general criterion for deciding where to place the “cut” between system and environment: the environment may be “external” or “internal”. The main purpose of this paper is to argue that decoherence is a relative phenomenon, better understood from a (...) closed-system perspective according to which the split of a closed quantum system into an open subsystem and its environment is just a way of selecting a particular space of relevant observables of the whole closed system. In order to support this claim, we shall consider the results obtained in a natural generalization of the simple spin-bath model usually studied in the literature. Our main thesis will lead us to two corollaries. First, the problem of identifying the system that decoheres is actually a pseudo-problem, which vanishes as soon as one acknowledges the relative nature of decoherence. Second, the usually supposed link between decoherence and energy dissipation is misguided. As previously pointed out, energy dissipation and decoherence are different phenomena, and we shall argue for this difference on the basis of the relative nature of decoherence. (shrink)

This paper discusses three shortcomings of the current state of the debate regarding historical evidence against scientific realism. Attending to these issues will direct the debate away from over-generalising wholesale arguments.

Are shapes of objects intrinsic to them? The issue has been intensely debated. Special relativity (SR) adds a new dimension to it by relativizing three-dimensional (3D) shapes not just to times, but to times-in-frames. Arguably, however, such relativized spatial shapes are mere perspectival representations of an invariant, hence intrinsic, four-dimensional (4D) shape of an object in Minkowski spacetime. In a recent note, Matthew Davidson questions the intrinsicality of 4D shapes in SR. I show that his conclusion and the reasoning behind (...) it are in error. (shrink)

Stopping rules — rules dictating when to stop accumulating data and start analyzing it for the purposes of inferring from the experiment — divide Bayesians, Likelihoodists and classical statistical approaches to inference. Although the relationship between Bayesian philosophy of science and stopping rules can be complex (cf. Steel 2003), in general, Bayesians regard stopping rules as irrelevant to what inference should be drawn from the data. This position clashes with classical statistical accounts. For orthodox statistics, stopping rules do matter to (...) what inference should be drawn from the data. "The dispute over stopping rule is far from being a marginal quibble, but is instead a striking illustration of the divergence of fundamental aims and standards separating Bayesians and advocates of orthodox statistical methods" (Steel 2004, 195) ... (shrink)

The old antagonism between the Quinean and the Duhemian view on underdetermination is reexamined. In this respect, two theses will be defended. First, it is argued that the main differences between Quine's and Duhem's versions of underdetermination derive from a different attitude towards the history of science. While Quine considered underdetermination from an ahistorical, a logical point of view, Duhem approached it as a distinguished historian of physics. On this basis, a logical and a historical version of the underdetermination thesis (...) can be distinguished. The second thesis of the article is that the main objections against underdetermination are fatal only to the logical rendering. Taken together, the two theses constitute a defence of underdetermination. (shrink)

Suppose that several observations “coincide,” meaning that they are similar in some interesting respect. Is this coinciding a mere coincidence, or does it derive from a common cause? Those who reason about this kind of question—whether they embrace the first answer or the second—often deploy a mode of inference that I call probabilistic modus tollens. In this chapter I criticize probabilistic modus tollens and consider likelihood and Bayesian frameworks for reasoning about coincidences. I also consider the perspective offered by model (...) selection theory (including the Akaike information criterion), and argue that model selection often provides important insights. (shrink)

There are famously two main metaphysics of persistence, namely three and four-dimensionalism. Both yield a particular solution to the so called puzzle of change. I argue that typical three-dimensionalist solutions to the puzzle face insurmountable difficulties even in the simplest relativistic setting, that of Minkowski spacetime.

When do objects at different times compose a further object? This is the question of diachronic composition. The universalist answers, ‘under any conditions whatsoever’. Others argue for restrictions on diachronic composition: composition occurs only when certain conditions are met. Recently, some philosophers have argued that restrictions on diachronic compositions are motivated by our best physical theories. In Persistence and Spacetime and elsewhere, Yuri Balashov argues that diachronic compositions are restricted in terms of causal connections between object stages. In a recent (...) article, Nikk Effingham argues that the standard objections to views that endorse restrictions on composition do not apply to a view that restricts composition according to compliance with the laws of nature. On the face of it, such restrictions on diachronic composition preserve our common-sense ontology while eliminating from it scientifically revisionary objects that travel faster than the speed of light. I argue that these attempts to restrict diachronic composition by appealing to either causal or nomological constraints face insurmountable difficulties within the context of special relativity. I discuss how the universalist should best respond to Hudson’s argument for superluminal objects, and in doing so, I present and defend a new sufficient condition for motion that does not entail that such objects are in superluminal motion. 1 Introduction2 Diachronic Composition3 Diachronic Composition and Superluminal Objects4 Restricting Diachronic Composition5 Causal and Nomological Restrictions on Composition in a Relativistic Context6 Superluminal Objects and Motion7 Conclusion. (shrink)

An introduction to composition, persistence, and identity.