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)

Presentism is held by most to be the intuitive theory of time, due in large part to the view's supposed preservation of time's passage. In this paper, I strike a blow against presentism's intuitive pull by showing how the presentist, contrary to overwhelming popular belief, is unable to establish temporal change upon which the passage of time is based. I begin by arguing that the presentist's two central ontological commitments, the Present Thesis and the Change Thesis, are incompatible. The main (...) problem is that satisfying the Change Thesis to establish passage requires the existence of more than one moment. This conflicts with the Present Thesis that only the present moment exists. The presentist's response is to appeal to surrogates to stand proxy for the past, so as to account for the difference between what does exist and what did exist. I argue that, for this surrogate strategy to be successful, the proposed surrogates must track what actually happened. I demonstrate that there is no guarantee that t.. (shrink)

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)

Relativity allegedly contradicts presentism, the dynamic view of time and reality, according to which temporal passage is conceived of as an existentially distinguished ‘moving’ now. Against this common belief, the paper motivates a presentist interpretation of spacetime: It is argued that the fundamental concept of time—proper time—cannot be characterized by the earlier-later relation, i.e., not in the B-theoretical sense. Only the presentist can provide a temporal understanding of the twins’ paradox and of universes with closed timelike curves.

Endurantism is not inconsistent with the theory of special relativity, or so I shall argue. Endurantism is not committed to presentism, and thus not committed to a metaphysics that is at least prima facie inconsistent with special relativity. Nor is special relativity inconsistent with the idea that objects are wholly present at a time just if all of their parts co-exist at that time. For the endurantist notion of co-existence in terms of which “wholly present” is defined, is not, I (...) will argue, a notion according to which co-existence is transitive. Although an absence of absolute simultaneity presents some problems for the endurantist claim that objects are wholly present whenever they exist, there are a number of ways that the endurantist can respond to this difficulty. Thus, I conclude, considerations pertaining to the theory of special relativity certainly do not rule out endurantism as a metaphysics of persistence. (shrink)

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.

We have two aims in this paper. The first is to provide the reader with a critical guide to recent work on relativity and persistence by Balashov, Gilmore and others. Much of this work investigates whether endurantism can be sustained in the context of relativity. Several arguments have been advanced that aim to show that it cannot. We find these unpersuasive, and will add our own criticisms to those we review. Our second aim, which complements the first, is to demarcate (...) the most defensible form of relativistic endurantism. A recurring theme of this paper is that even those philosophers who do worry about relativity have not taken it seriously enough. (shrink)

Penrose's conformal cyclic cosmology describes the cosmos as a collection of successive universes, the so-called aeons. The beginning and ending of our universe are directly connected to two other, anterior and posterior, universes. Penrose considers but rules out a different interpretation of conformal cyclic cosmology: that the beginning of our universe is connected to its own end in a cosmic loop. The paper argues that the view, aeon monism, should be regarded as a natural interpretation of conformal cyclic cosmology and (...) discusses its implications for the concept of eternal return in light of the most popular metaphysics of time. (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)

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)

The present work explores various ways in which contingent evidence can impact metaphysics, while advocating that, just as a scientific realist allows for ampliative inferences to the unobservable, ampliative inferences from possible evidence can warrant possibility claims that lie beyond the reach of sensorial imagination. In slogan form: possible evidence is a guide to possibility. Drawing on Shoemaker’s (1969) argument for the possibility of time without change, I advocate the following principle: If there is a possible world at which the (...) observable facts make it objectively reasonable to conclude that p, then we should conclude that p is possibly true. This provides a route to contingentism in metaphysics, for, if one considers that there are worlds in which the observable facts make it objectively reasonable to conclude that p, and worlds in which the observable facts make it objectively reasonable to conclude that not-p, then my principle tells us that we should conclude that possibly-p and possibly not-p, i.e. that p is contingent. This contingency in what is reasonable to conclude, I suggest, occurs most saliently in debates where evidence of phenomenal experience and empirical science are marshalled to support one theory over another. I also explore some consequences of taking possible evidence to be a guide to possibility in this way, among them being an interesting modal analogue of the lottery paradox. (shrink)

The special theory of relativity (STR) is widely supposed to be in tension with A-theories of time, those giving special significance to the present moment. A-theories are diverse in the features they regard as distinctive of the present, but all agree that there is an absolute fact of the matter about which events have the feature of presentness. Famously, the standard notion of simultaneity operationalised within the theory of relativity is not absolute. If A-theorists accept relativistic physics, they must either (...) refine their A-theory and sever joint presentness from simultaneity (‘conciliatory’ responses to the problem), or supplement standard relativity by adding further spacetime structure that grounds a relation of absolute simultaneity (‘supplementing’ responses). This chapter considers the prospects for such approaches, concluding that while there is no knock-down argument from relativity against the A-theory, attempts to marry the A-theory with STR are more trouble than they are worth. (shrink)

Black holes are arguably the most extraordinary physical objects we know in the universe. Despite our thorough knowledge of black hole dynamics and our ability to solve Einstein’s equations in situations of ever increasing complexity, the deeper implications of the very existence of black holes for our understanding of space, time, causality, information, and many other things remain poorly understood. In this paper I survey some of these problems. If something is going to be clear from my presentation, I hope (...) it will be that around black holes science and metaphysics become more interwoven than anywhere else in the universe. (shrink)

There is a feeling of dissatisfaction with the traditional way of defining the A-theories of time. One reason is that these definitions rest on an ontological question—‘Do the future and the past exist?’—to which no non-speculative answer can be provided. Another reason is that these definitions fail to distinguish between various A-theories of time at all times and, therefore, cannot be regarded as essential to them. In the present paper, I make a fresh start in the debate, by introducing two (...) questions whose specific answers allow one to get a comprehensive categorization of the A-theories of time. This alternative way of defining the A-theories of time addresses the two above-mentioned issues and reveals the metaphysical singularity of underrated theories, such as the growing block theory. (shrink)

ABSTRACT Temporal eliminativism is the view that the present is privileged because past and future entities do not exist. Temporal ersatzism is the view that the present is privileged because, although past and future entities exist, they are not concrete. I argue that shifting from temporal eliminativism to temporal ersatzism can help to address objections to the former theory that are due to relativity theory—but only if temporal ersatzism is understood in a fairly specific way and only in so far (...) as the temporal ersatzist is willing to take on some prima facie surprising commitments. I close by showing how the claims that I make with respect to temporal ersatzism generalise to other theories of time on which the present is privileged, including McDaniel’s [2018] presentist existential pluralism. (shrink)

Recently, some have attempted to reformulate debates in first-order metaphysics, particularly in the metaphysics of time and modality, for reasons due to Williamson. In this paper, we focus on the ways in which the likes of Cameron, Correia and Rosenkranz, Deasy, Ingram, Tallant, Viebahn, inter alia, have initiated and responded to attempts to capture the core of presentism using a formal, logical machinery. We argue that such attempts are doomed to fail because there is no theoretical core to presentism. There (...) is no single view or family of views that is presentism. (shrink)

This chapter discusses some aspects of the relation between temporal experience and the A versus B debate. To begin with, I provide an overview of the A versus B debate and, following Baron et al. (2015), distinguish between two B-theoretic responses to the A- theoretic argument from experience, veridicalism and illusionism. I then argue for veridicalism over illusionism, by examining our (putative) experiences as of presentness and as of time passing. I close with some remarks on the relation between veridicalism (...) and a deflationary view of the A versus B debate. I suggest that the deflationary view can provide further support for veridicalism. (shrink)

The aim of this doctoral dissertation is to closely explore the nature of Einstein’s block universe and to tease out its implications for the nature of time and human freedom. Four questions, in particular, are central to this dissertation, and set out the four dimensions of this philosophical investigation: (1) Does the block universe view of time follow inevitably from the theory of special relativity? (2) Is there room for the passage of time in the block universe? (3) Can we (...) distinguish past from future in the block universe? (4) Is there room for human freedom in the block universe? Although the answer of most philosophers would be yes, triple no, my own answer, controversially, is no, triple yes. -/- I thereby challenge the status quo with respect to each of these metaphysical questions, and argue that none of these questions can be answered from looking at physics alone. Physics may constrain our metaphysics, but it certainly does not settle it. What is needed in order to answer these questions, are additional metaphysical assumptions that fall outside the scope of modern physics. My primary goal in this dissertation, therefore, is not to settle the debates on the nature of time and human freedom, but to clarify them by expliciting the metaphysical assumptions that are otherwise left implicit. (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)

This paper considers a problem for dynamic presentism that has received little attention: its apparent inability to accommodate the duration of events (such as conscious experiences). After outlining the problem, I defend presentism from it. This defence proceeds in two stages. First, I argue the objection rests on a faulty assumption: that duration is temporal extension. The paper challenges that assumption on several different ways of conceiving of temporal extension. This is the negative case and forms the bulk of the (...) paper. Second, after diagnosing the error leading to the identification of duration with temporal extension, I outline a new presentist-friendly account of duration that avoids the problem. In particular, a non-reductive account of duration is offered that treats it as a primitive quality which bestows its possessor with a certain modal quality: that the possessor potentially does not change whilst there are changes in its environs. This is the positive case. Together the positive and negative cases provide presentism with an interesting and novel way of overcoming the problem of duration. (shrink)

Neither special nor general relativity make any use of a notion of absolute simultaneity. Since A-Theories about time do make use of such a notion, it is natural to suspect that relativity and A-Theory are inconsistent. Many authors have argued that they are in fact not inconsistent, and I agree with that diagnosis here. But that doesn’t mean, as these authors seem to think, that A-Theory and relativity are happy bedfellows. I argue that relativity gives us good reason to reject (...) the A-Theory, even though strict inconsistency isn’t that reason. (shrink)

I begin by giving reasons to accept the block-universe view, the strongly supported by physics view that we live in a four-dimensional world. According to it, the past and the future are as real as the present. As a result, it seems that the future is determined in the sense that what will be the case will necessarily be the case. In the dissertation, I examine whether we have to accept this consequence. I show that we do not have to (...) bite the bullet: the future might be both real and contingent. I first start to consider modal realism (possible futures are real) as a possible solution. However, I propose then another account, actualist (positing the reality of only one possible world: the space-time we live in). This solution relies on a conventionalist theory about metaphysical modality (Sidelle, 1989). It states that modal modality is purely conventional. In combination with a realist interpretation of natural modality (causal and/or nomological), this framework allows me to propose that the future is conventionally closed and naturally contingent. In this view, the necessity of the future holds in virtue of linguistic conventions and then is conventionally necessary. But this is a distinct phenomenon from the natural contingency of the future: the future is naturally contingent because there are mind-independent probabilistic relations holding between the present and the future. This solution has strong consequences: most importantly, an anti-realist view about ordinary objects and physical particles. I end up by presenting and arguing in favour of the general image of the world that comes out from these views. (shrink)

Metaphysics is the part of philosophy that asks questions about the nature of reality – about what there is, and what it is like. The metaphysics of time is the part of the philosophy of time that asks questions about the nature of temporal reality. One central such question is that of whether time passes or flows, or whether it has a dynamic aspect.

This thesis is a study of the notion of time in modern physics, consisting of two parts. Part I takes seriously the doctrine that modern physics should be treated as the primary guide to the nature of time. To this end, it offers an analysis of the various conceptions of time that emerge in the context of various physical theories and, furthermore, an analysis of the relation between these conceptions of time and the more orthodox philosophical views on the nature (...) of time. In Part II I explore the interpretation of nonrelativistic quantum mechanics in light of the suggestion that an overly Newtonian conception of time might be contributing to some of the difficulties that we face in interpreting the quantum mechanical formalism. In particular, I argue in favour of introducing backwards-in-time causal influences as part of an alternative conception of time that is consistent with the picture of reality that arises in the context of the quantum formalism. Moreover, I demonstrate that this conception of time can already be found in a particular formulation of classical mechanics. One might see that one of the central themes of Part II originates from a failure to heed properly the doctrine of Part I: study into the nature of time should be guided by modern physics and thus we should be careful not to insert a preconceived Newtonian conception of time unwittingly into our interpretation of the quantum mechanical formalism. Thus, whereas Part I is intended as a demonstration of methodology with respect to the study of time, Part II in a sense explores a confusion that can be seen as arising in the absence of this methodology. (shrink)

Temporal ersatzism is the view that past entities exist, but are not concrete. The view is analogous to modal ersatzism, according to which merely possible worlds exist, but are not concrete. The goal of this paper is to give the reader a sense of the scope of available temporal ersatzist views, the ways in which the analogy with modal ersatzism may be helpful in characterizing and defending those views, and the sorts of considerations that are relevant when evaluating particular versions (...) of temporal ersatzism. (shrink)

The perplexing nature of time has been more contemplated, speculated, written, and debated about over the ages than virtually any other subject, with the possible exception of religion. Yet time seems more elusive than the vast majority of other metaphysical concepts. Time remains mysterious, for we lack an understanding of time at a basic physical level. Concepts of time in theories of modern physics and time as found in contemporary western analytic philosophy are discussed.

In light of the Special Theory of Relativity and the Minkowski creation of ‘spacetime’, the universe is taken to be a four-dimensional entity which postulates bodies as existing within a temporally extended reality. The Special Theory of Relativity’s implications liken the nature of the universe to a ‘block’ within which all events coexist equally in spacetime. Such a view strikes against the very essence of presentism, which holds that all that exists is the instantaneous state of objects in the present (...) moment. With respect to the present moment, events have a clear division into the past or future, however such regions do not exist in reality and the universe is a three-dimensional entity. The consequences of a four-dimensional universe are disturbing to say the least for our everyday human experience, with once objective facts about reality becoming dependent upon an observer’s relative motion and the debate over the extent of true free will in a Block Universe. This paper will look at arguments which seek to rescue the presentist view in light of Special Relativity so such four-dimensionalist implications do not have to be accepted. Two approaches will be considered. The first accepts that presentism is incompatible with Special Relativity, and seeks to show that the theory is ultimately false. The second holds that it is the Block Universe interpretation of Special Relativity that is wrong, and a version of presentism can be reconciled with Special Relativity. The paper will expound and critically examine both of these approaches to review whether the case for the three-dimensionalist and a fundamental passage of time can be made. (shrink)

The New A-theory of Time is the view, to be elaborated and defended in this article, that many times exist, and that time is real in virtue of every moment in time bearing each of the so-called A-properties: past, present and future. I argue that TNAT is at least as theoretically virtuous as mainstream views in the philosophy of time and may have some claim to being our best theory of time. I show that the properties ‘past’, ‘present’ and ‘future’ (...) can be understood as compatible intrinsic properties. Having demonstrated that this account of the A-properties is coherent, I go on to demonstrate how TNAT can give us an account of passage, change and the truth-conditions for temporal sentences. In the final section of the article, I develop a tentative argument in favour of TNAT, though concede that we have to settle for the result that TNAT is on a par with our other theories of time. In the remainder of this opening section, my aim is to situate the current proposal as a direct response to Mc.. (shrink)

Science depends on judgments of the bearing of evidence on theory. Scientists must judge whether an observation or the result of an experiment supports, disconfirms, or is simply irrelevant to a given hypothesis. Similarly, scientists may judge that, given all the available evidence, a hypothesis ought to be accepted as correct or nearly so, rejected as false, or neither. Occasionally, these evidential judgments can be made on deductive grounds. If an experimental result strictly contradicts a hypothesis, then the truth of (...) the data deductively entails the falsity of the hypothesis. In the great majority of cases, however, the connection between evidence and hypothesis is non-demonstrative, or inductive. In particular, this is so whenever a general hypothesis is inferred to be correct on the basis of the available data, since the truth of the data will not deductively entail the truth of the hypothesis. It always remains possible that the hypothesis is false even though the data are correct. (shrink)

The paper first sketches out a reply to the underdetermination challenge and the incommensurability challenge that rebuts the sceptical conclusions of these challenges and that is sufficient to lay the ground for the project of a metaphysics of nature. That metaphysics is as hypothetical as are our scientific theories. The paper then explains how can one can argue for certain views in the metaphysics of nature based on our current fundamental physical theories, namely the commitments to a tenseless theory of (...) time and existence instead of a tensed one, to events instead of substances, and to relations instead of intrinsic properties. Finally, the paper mentions the themes of causation, laws and dispositions. (shrink)

In this paper I argue that the debate between the so-called “presentists” – according to whom only the present is real – and the “eternalists”, according to whom past present and future are equally real, has no ontological significance. In particular, once we carefully distinguish between a tensed and a tenseless sense of existence, it is difficult to find a single ontological claim on which the two parties could disagree. Since the choice of using a tense or a tenseless language (...) is dictated by purely pragmatic reasons, we should abstain from bringing to bear pseudo-debates generated by the “tensed” or the “tenseless theories” of time on the question of understanding the philosophical implications of contemporary spacetime theories, or notions like becoming, change and persistence in time. (shrink)

Callender [2017] claims that contemporary science demonstrates that there is no objective present and no objective flow of time, especially since all sensed events come from the past, our various senses need different amounts of time to react, and there are enough asymmetries in the physical world to explain our experience of time. This paper holds that, although Callender’s arguments for the subjectivity of the flow of time are unconvincing, the scientific discoveries and arguments he indicates can still be applied (...) to improve theories of the objective flow of time. The paper develops precisely such a theory, one which introduces multiple individual proper presents for all of the objects that make up our world. (shrink)

Many physicists have thought that absolute time became otiose with the introduction of Special Relativity. William Lane Craig disagrees. Craig argues that although relativity is empirically adequate within a domain of application, relativity is literally false and should be supplanted by a Neo-Lorentzian alternative that allows for absolute time. Meanwhile, Craig and co-author James Sinclair have argued that physical cosmology supports the conclusion that physical reality began to exist at a finite time in the past. However, on their view, the (...) beginning of physical reality requires the objective passage of absolute time, so that the beginning of physical reality stands or falls with Craig's Neo-Lorentzian metaphysics. Here, I raise doubts about whether, given Craig's NeoLorentzian metaphysics, physical cosmology could adequately support a beginning of physical reality within the finite past. Craig and Sinclair's conception of the beginning of the universe requires a past boundary to the universe. A past boundary to the universe cannot be directly observed and so must be inferred from the observed matter-energy distribution in conjunction with auxilary hypotheses drawn from a substantive physical theory. Craig's brand of Neo Lorentzianism has not been sufficiently well specified so as to infer either that there is a past boundary or that the boundary is located in the finite past. Consequently, Neo Lorentzianism implicitly introduces a form of skepticism that removes the ability that we might have otherwise had to infer a beginning of the universe. Furthermore, in analyzing traditional big bang models, I develop criteria that Neo-Lorentzians should deploy in thinking about the direction and duration of time in cosmological models generally. For my last task, I apply the same criteria to bounce cosmologies and show that Craig and Sinclair have been wrong to interpret bounce cosmologies as including a beginning of physical reality. (shrink)

The aim of the present paper is to show that presentism cannot answer the truthmaker objection in a satisfactory manner. For such, two main categories of presentist solutions were studied: the first kind states that truthmakers can’t provide any objection to presentism, while the second type tries to ground past truths by postulating new ontological categories, which were rejected, mainly because of their use of ad hoc ontologies. Also, I showed how the presentist should adopt antirealism about the past in (...) case she wants to maintain a simple ontology. Being that said, I conclude that presentism cannot offer satisfactory truthmakers to past truths. (shrink)

McTaggart famously introduced the A- and B-series as rival metaphysical accounts of time. This paper shall reorient the debate over the original distinction. Instead of treating the series as competing theories about the nature of time, it will be argued that they are different viewpoints on a world that is fundamentally physical. To that end, non-reductive physicalism is proposed to reconcile the series.

The debate on the conventionality of simultaneity and the debate on the dimensionality of the world have been central in the philosophy of special relativity. The link between both debates however has rarely been explored. The purpose of this paper is to gauge what implications the former debate has for the latter. I show the situation to be much more subtle than was previously argued, and explain how the ontic versus epistemic distinction in the former debate impacts the latter. Despite (...) claims to the contrary, I conclude that special relativity leaves the debate on the dimensionality of the world underdetermined. (shrink)

There are two main camps in 20th-century philosophy of time: A-theorists who believe in the dynamic model of reality, and B-theorists who maintain a static model of reality. After the publication of Putnam’s influential article, “time and physical geometry”, the implications of the Special Theory of Relativity became serious in metaphysical discussions about temporal reality. Some philosophers argued that this theory contradicts the dynamic model and implies the ontology of the static model, namely, the objective reality of the present, past (...) and future events. In response, some advocates of the dynamic model argued that there can be dynamic models in relativistic setting, though they are different, radically, from old theories of dynamic reality. In this paper, first, I shall discuss how special relativity contradicts the traditional dynamic model and, then, how new dynamic models imply a relative concept of reality, in contrast to its old absolute concept and, so, why these strategies are very unintuitive. Finally, I shall argue that this radical conceptual shift about reality is, not only unintuitive, but unwarranted and, in some sense, inconsistent as well. (shrink)

In a lot of domains in metaphysics the tacit assumption has been that whichever metaphysical principles turn out to be true, these will be necessarily true. Let us call necessitarianism about some domain the thesis that the right metaphysics of that domain is necessary. Necessitarianism has flourished. In the philosophy of maths we find it held that if mathematical objects exist, then they do of necessity. Mathematical Platonists affirm the necessary existence of mathematical objects (see for instance Hale and Wright (...) 1992 and 1994; Wright 1983 and 1988; Schiffer 1996; Resnik 1997; Shapiro 1997 and Zalta 1988) while mathematical nominalists, usually in the form of fictionalists, hold that necessarily such objects fail to exist (see for instance Balaguer 1996 and 1998; Rosen 2001 and Yablo 2005). In metaphysics more generally, until recently it was more or less assumed that whatever the right account of composition—the account of under what conditions some xs compose a y—that account will be necessarily true (for a discussion of theories of composition see Simons 1987 and van Inwagen 1987 and 1990; the modal status of the composition relation is explicitly addressed in Schaffer 2007; Parsons 2006 and Cameron 2007). Similarly, it has generally been assumed that whatever the right account is of the nature of properties, whether they be universals, tropes, or whether nominalism is true, that account will be necessarily true (though see Rosen 2006 for a recent suggestion to the contrary). In considering theories of persistence it has been widely held that whether objects endure or perdure through time is a matter of necessity (Sider 2001; though see Lewis 1999 p227 who defends contingent perdurantism). And with respect to theories of time it is frequently held that whichever of the A- or B-theory is true is necessarily true. A-theorists often argue that there is time in a world only if the A-theory is true at that world (see for instance McTaggart 1903; Markosian 2004; Bigelow 1996; Craig 2001) while B-theorists often argue that the A-theory is internally inconsistent (Smart 1987; Mellor 1998; Savitt 2000 and Le Poidevin 1991). Once again, we find a few recent contingentist dissenters. Bourne (2006) suggests that it is a contingent feature of time that it is tensed, and thus that the A-theory is contingently true. Worlds in which there exist only B-theoretic properties are worlds with time, it is just that time in those worlds time is radically different to the way it is actually. Other defenders of the B-theory, though not expressly contingentists, do offer arguments against versions of the A-theory that try to show that such A-theories theories are inconsistent with the actual laws of nature (see for instance Saunders 2002 and Callender 2000); these arguments, at least, leave room for the possibility that the A-theories in question are contingently false (at least on the assumption that the laws of nature are themselves contingent, an assumption that not everyone accepts). Despite some notable exceptions, necessitarianism has flourished in many, if not most, domains in metaphysics. One such exception is Lewis’ famous defence of Humean supervenience as a contingent claim about our world. Lewis does not argue that necessarily, the supervenience base for all matters of fact in a world is nothing but a vast mosaic of local matters of particular fact. Rather, he thinks that we have reason to think that our world is one in which Humean supervenience holds (see Lewis 1986 p9-10 and 1994). Another exception to the necessitarian orthodoxy is to be found in the lively debate about the modal status of the laws of nature. Here, if anything, contingentism has been the dominating force, with it generally being held that there are possible worlds in which different laws of nature hold (this view is defended by, among others, Lewis 1986 and 2010; Schaffer 2005 and Sidelle 2002). Necessitarian dissenters hold that the laws of nature are necessary, frequently because they think it is necessary that fundamental properties have the causal or nomic profiles they do (see for instance Shoemaker 1980 and 1988; Swoyer 1982; Bird 1995; Ellis and Lierse 1994). Nevertheless, when it comes to thinking about the nature of the laws themselves, the necessitarian presumption is back on firm footing. Though there is disagreement about whether the laws are generalisations that feature in the most virtuous true axiomatisation of all the particular matters of fact (often known as the Humean view of laws and defended by Ramsey 1978; Lewis 1986 and Beebee 2000) or whether laws are relations of necessity that hold between universals (a view defended by Armstrong 1983; Dretske 1977; Tooley 1977 and Carroll 1990) no one has seriously suggested that it might be a contingent matter which of these is the right account of laws. The necessitarian orthodoxy is not surprising since metaphysics is largely an a priori process. While a priori reasoning may be used to determine whether a proposition is necessary or contingent, it is not well placed (in the absence of a posteriori evidence) to determine whether a contingent proposition is actually true or false. Since metaphysicians aim to tell us which principles are true in which worlds, on the face of it the discovery that metaphysical principles are contingent seems to make part of the task of metaphysics epistemically intractable. In what follows I consider two reasons one might end up embracing contingentism and whether this would lead one into epistemic difficulty. The following section considers a route to contingent metaphysical truths that proceeds via a combination of conceptual necessities and empirical discoveries. Section 3 considers whether there might be synthetic contingent metaphysical truths, and the final section raises the question of whether if there were such truths we would be well placed to come to know them. (shrink)

Actualism is the view that only actually existing things exist. Presentism is the view that only presently existing things exist. In this paper, I argue that being an actualist without also being a presentist is not as easy as many philosophers seem to think. A common objection to presentism is that there is an unavoidable conflict between presentism and relativity theory. But actualists who do not wish to be presentists cannot point to this relativity objection alone to support their position. (...) Unless they have some antecedent reason for thinking that actualism is more plausible than presentism, anyone who is moved by the relativity objection to give up presentism should be moved by a related objection to give up actualism as well. If there is a reason to be an actualist without also being a presentist, it must go beyond the relativity objection to presentism. (shrink)

The idea of a moving present or ‘now’ seems to form part of our most basic beliefs about reality. Such a present, however, is not reflected in any of our theories of the physical world. I show in this article that presentism, the doctrine that only what is present exists, is in conflict with modern relativistic cosmology and recent advances in neurosciences. I argue for a tenseless view of time, where what we call ‘the present’ is just an emergent secondary (...) quality arising from the interaction of perceiving self-conscious individuals with their environment. I maintain that there is no flow of time, but just an ordered system of events. (shrink)

I formulate a theory of persistence in the endurantist family and pose a problem for the conjunction of this theory with orthodox versions of special or general relativity. The problem centers around the question: Where are things?

By considering situations from the paradox of the twins in relativity, it is shown that time passes at different rates along different world lines, answering some well-known objections. The best explanation for the different rates is that time indeed passes. If time along a world line is something with a rate, and a variable rate, then it is difficult to see it as merely a unique, invariant, monotonic parameter without any further explanation of what it is. Although it could, conceivably, (...) be explained by the flow of something, it is better explained by the passing of a point present, which faces the problem that there is no absolute simultaneity in special relativity so that the present for an object is confined to just that object. This raises problems about presentism, eternalism, simultaneity, and special relativity. These issues are addressed first by giving accounts of presentism and eternalism and then an account of existence and times for objects relative to world lines. Finally, an analogy between a world of relativistic objects and Leibniz’s ontology of monads. (shrink)

Thing ontologies are ontologies that consider the universe to be made up of a plurality of discrete objects. Non-thing ontologies can take the form of ontologies of discrete objects, too, but not necessarily so: they can also be conceived as ontologies of one continuous object. The paper considers the central versions of ontologies of discrete objects first, starting with thing ontologies, moving from there to non-thing ontologies of discrete objects and finally ontologies of one continuous object.

Presentism is, roughly, the metaphysical doctrine that maintains that whatever exists, exists in the present. The compatibility of presentism with the theories of special and general relativity was much debated in recent years. It has been argued that at least some versions of presentism are consistent with time-orientable models of general relativity. In this paper we confront the thesis of presentism with relativistic physics, in the strong gravitational limit where black holes are formed. We conclude that the presentist position is (...) at odds with the existence of black holes and other compact objects in the universe. A revision of the thesis is necessary, if it is intended to be consistent with the current scientific view of the universe. (shrink)

Time is what clocks are used to measure. Information about time tells the durations of events and when they occur and which events happen before which others, so time plays a very significant role in the universe’s structure, including the structure of our personal lives. But carefully describing time’s properties has led to many unresolved issues, both philosophical and scientific.

It has been argued that the standard formulation of the Special Theory of Relativity is not only incompatible with presentism, but also strongly indicates the truth of eternalism. We should, however, distinguish two claims concerning the ontological implications of STR: STR is inconsistent with every ontology which requires an absolute relation of simultaneity; and STR implies that eternalism is the only possible ontology of time. There have been a wide range of responses designed to reject these claims, both jointly and (...) independently. For example, one way of rejecting claim is by rejecting claim : thus, one would argue that STR can be revised or interpreted in such a way that it allows an absolute relation of simultaneity. Another way of rejecting claim is by questioning the equivalency of the relation ‘being real as of’. The main purpose of this paper is to raise a new line of objection against concluding eternalism from the relativity of simultaneity. I argue that there is a way to deny claim without denying claim and also without denying the equivalency of relation R. The argument which I present rests on a metaphysical assumption concerning the relation of simultaneity : the assumption that the SIM holds basically between space–time points as opposed to holding basically between events. (shrink)