Three- and Four-Dimensionalism

Are concrete objects in some sense made up of the properties they exemplify? A distinguished tradition holds they are. I begin by defending the distinction: there is a real and not just semantic distinction between asserting and denying that concrete objects have their properties as parts. I then argue in favor of the view that concrete objects are not made up of their parts. First, this view has less ontological baggage than its opponent. Next, the supposed advantages of the alternative (...) view—its superiority in understanding persistence, exemplification, or the possibility of diverse duplicates—dissipate under analysis. (shrink)

The possibility of multilocation --- 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 (i) location of immanent universals, (ii) multi-location of mereologically changing three-dimensional objects , (iii) multi-location of mereologically complex objects, and (iv) mereologically simple but extended objects. (shrink)

The recent literature on the nature of persistence features a handful of imaginative cases in which an object seems to colocate with itself. So far, discussion of these cases has focused primarily on how they defy the standard endurantist approaches to the problem of temporary intrinsics. But in this article, I set that issue aside and argue that cases of apparent self-colocation also pose another problem for the endurantist. While the perdurantist seems to have a fairly straightforward account of self-colocation, (...) the endurantist has a hard time saying exactly what it would be for an object to be self-colocated. After introducing this problem and explaining how the perdurantist can circumvent it with little difficulty, I discuss a number of tempting endurantist solutions that ultimately fail. Then I suggest an endurantist solution which I think is more promising, but which requires the endurantist to deny that apparent cases of self-colocation are genuine cases of self-colocation. (shrink)

There has been a growing charge that perdurantism—with its bloated ontology of very person-like objects that coincide persons—implies the repugnant conclusion that we are morally obliged to be feckless. I argue that this charge critically overlooks the epistemic situation—what I call the ‘veil of ignorance’—that perdurantists find themselves in. Though the veil of ignorance still requires an alteration of our commonsense understanding of the demands on action, I argue for two conclusions. The first is that the alteration that is required (...) isn’t a moral one, but rather an alteration of prudential reasoning. Second, and more importantly, this alteration isn’t necessarily a repugnant one. In fact, given that it prudentially pushes one towards greater impartiality, it may be seen as a point in favor of perdurantism. (shrink)

This article offers a novel solution to the problem of material constitution: by including non-concrete objects among the parts of material objects, we can avoid having a statue and its constituent piece of clay composed of all the same proper parts. Non-concrete objects—objects that aren’t concrete, but possibly are—have been used in defense of the claim that everything necessarily exists. But the account offered shows that non-concreta are independently useful in other domains as well. The resulting view falls under a (...) ‘nonmaterial partist’ class of views that includes, in particular, Laurie Paul’s and Kathrin Koslicki’s constitution views; ones where material objects have properties or structures as parts respectively. The article gives reasons for preferring the non-concretist solution over these other non-material partist views and defends it against objections. (shrink)

Some philosophers say that in special relativity, four-dimensional stuff is invariant in some sense that three-dimensional stuff is not. I show that this claim is false.

In this paper, I tackle the problem of diachronic identity. Far from providing a criterion for identity over time, the aim of this work is to understand if this issue pertains to ontology, conceived as that part of philosophy that tries to answer the question about what entities exist, and metaphysics, conceived as that part of philosophy that tries to explain, of those entities, what they are. On the face of it, only metaphysics has the task to solve this problem, (...) but I argue that this is false. Through the analysis of different theories concerning identity through time, I show how both ontology and metaphysics are concerned with the problem of diachronic identity, and how actually ontology turns out to be primary in solving the problem. (shrink)

In this paper I develop a version of universalism that is non-mereological. Broadly speaking, non-mereological universalism is the thesis that for any arbitrary set of objects and times, there is a persisting object which, at each of those times, will be constituted by those of the objects that exist at that time. I consider two general versions of non-mereological universalism, one which takes basic simples to be enduring objects, and the other which takes simples to be instantaneous objects. This yields (...) three versions of endurantism, of which I ultimately defend the version I call universalist endurantism. Universalist endurantism is the thesis that for any arbitrary set S of instantaneous simples that exist at the same instant, there exists a fusion of the members of S, and for any arbitrary set S* of instantaneous fusions each of which exist at a different instant, there exists an enduring object O that is constituted by those fusions at those instants. Universalist endurantism is ‘non-mereological’ in that the relation that holds between instantaneous fusions and persisting objects is not the part/whole relation, but rather, is the relation of constitution, thus allowing that the persisting objects are three rather than four dimensional. I argue that universalist endurantism not only has the various benefits of mereological universalism in allowing vagueness to be explicated as semantic indeterminacy, but in addition allows the endurantist to hold that some properties are genuinely intrinsic and are exemplified simpliciter. (shrink)

Grenon and Smith (2004) propose a framework for the ontology of things in space and time involving and invoking the distinction between continuants and occurrents, which has become a key element of Basic Formal Ontology (BFO). The terminology of SNAP (from “snapshot:” state of a continuant at a time) and SPAN (how an occurrent develops over an interval or timespan) occurs in that paper’s title. While any commonsense ontology will have a place for both continuants and occurrents, there is much (...) room for philosophical debate on whether one of them is more basic than the other, or can be reduced to the other, or whether they are equally fundamental, or whether they are two different perspectives on the same reality. Grenon and Smith opt for the last of these. They call the accounts of continuants (SNAP) and occurrents (SPAN) both “ontologies.” They do not have a single ontology of all that is in space and time. This dialog throws a few of the common arguments around a bit and comes to no sure conclusion. But one of the characters bears a faint resemblance to a certain Buffalonian philosopher. (shrink)

لم يكن العلم يومًا غريبًا عن الفلسفة، بل لقد أدت العلاقة الجدلية المستمرة بينهما إلى مزيد من المصداقية والقبول لبعض النماذج التفسيرية، سواء منها ما كان في الأصل نموذجًا فلسفيًا ثم وجد دعمًا علميًا – كنموذج الذرات والفـراغ عند «ديمرقــريطس» وتبنى النظرية الذرية الحديثة لإطاره العام – أو ما كان منها نموذجًا علميًا تم تداوله فلسفيًا – كنموذج النقاط المادية المتجاذبة عند »نيوتن« وتبنى معظم فلاسفة الحقبة الحديثة له. وفي هذا المقال يهتم الدكتور صلاح عثمان بمناقشة نموذج شجرة الكون لفيلسوف (...) العلم الكندي المعاصر «ستورس مكال»، وأوجه الاختلاف بينه وبين النماذج التفسيرية المماثلة القائمة على فكرة متصل الزمان – مكان، ويُركز على ما يقترحه النموذج من حلٍ لواحدةٍ من أصعب مشكلات العلم والمنطق والفلسفة، ألا وهى مشكلة تحديد شروط الصدق للقضايا المنطقية الشرطية المناقضة للواقع؛ أعني تلك التي لا تُعبر عن حوادث وقعت بالفعل، بل كان من المفترض أن تقع، وبالتالي يصعب تحديد قيمة صدق (صادقة أو كاذبة) لها. هذا النوع من القضايا يرتبط ارتباطًا وثيقًا بتصور القانون العلمي، وتحفل به المقاربات التاريخية والخطط المستقبلية للأفراد والحكومات، لذا تعددت محاولات معالجته من قبل الفلاسفة، وهو ما تجلى مثلاً في النظرية الاستدلالية للقضايا الشرطية التي اقترحها «نيلسون جودمان», ونظرية العقول واعتقاداتها للفيلسوف الإنجليزي «فرانك رامزي», ونظرية العوالم الممكنة للفيلسوفين الأمريكيين المعاصـرين «روبرت ستالنيكر»، و«ديفيد لويس»، وأخيرًا نظرية النموذج الشجري لـ «ستورس مكال». وينتهي المقال إلى نتيجة مؤداها نجاح النموذج في معالجة المشكلة، وإن كان ذلك مرهونًا بالتأكيد على موضوعية قيم الصدق والاحتمال التي تحوزها القضايا الشرطية في مقابل الذات المُدركة، تلك التي تنتقل عبر غُرف انتظار متعددة تقترب رويدًا رويدًا من الحقيقة. . (shrink)

We propose an ontological theory that is powerful enough to describe both complex spatio-temporal processes (occurrents) and the enduring entities (continuants) that participate in such processes. For this purpose we distinguish between meta-ontology and token ontologies. Token ontologies fall into two major categories: ontologies of type SPAN and ontologies of type SNAP. These represent two complementary perspectives on reality and result in distinct though compatible systems of categories. The meta-ontological level then describes the relationships between the different token ontologies. In (...) a SNAP (snapshot) ontology we have enduring entities such as substances, qualities, roles, functions as these exist to be inventoried at a given moment of time. In a SPAN ontology we have perduring entities such as processes and their parts and aggregates. We argue that both kinds of ontological theory are required, together with the metaontology which joins them together, in order to give a non-reductionistic account of both static and dynamic aspects of the geospatial world. (shrink)

The cohabitation theory is a popular solution to the problem of personal fission. It affirms that all the people who result from fission were there cohabiting the pre-fission body all along. Adopting this solution is an uncontroversial move for four-dimensionalists, but is it open to three-dimensionalists too? Some have thought so, but Katherine Hawley, Mark Johnston, and Eric Olson have argued to the contrary. They claim three-dimensionalists simply cannot be cohabitation theorists. In this paper, I explain how they can.

I argue that medieval solutions to the limit decision problem imply four-dimensionalism, i.e. the view according to which substances that persist through time are extended through time as well as through space, and have different temporal parts at different times.

This paper presents the strongest version of a non-perdurantist four-dimensionalism: a theory according to which persisting objects are four-dimensionally extended in space-time, but not in virtue of having maximal temporal parts. The aims of considering such a view are twofold. First, to evaluate whether such an account could provide a plausible middle ground between the two main competitor accounts of persistence: three-dimensionalism and perdurantist four-dimensionalism. Second, to see what light such a theory sheds on the debate between these two competitor (...) theories. I conclude that despite prima facie reasons to suppose that non-perdurantist four-dimensionalism might be a credible alternative to either other account of persistence, ultimately the view is unsuccessful. The reasons for its failure illuminate the sometimes stagnant debate between three-dimensionalists and perdurantists, providing new reasons to prefer a perdurantist metaphysics. (shrink)

This article defends novel approaches to what we are and how we persist. First it is claimed that we have disjunctive persistence conditions: we can persist by way of either biological continuity or psychological continuity. Then it is claimed that we are neither human beings nor persons essentially. Rather, we are essentially bio-psycho-continuers, a concept to be explained along the way. A variety of objections are considered and found wanting.

Comparative overall similarity lies at the basis of a lot of recent metaphysics and epistemology. It is a poor foundation. Overall similarity is supposed to be an aggregate of similarities and differences in various respects. But there is no good way of combining them all.

The notion of existence is a very puzzling one philosophically. Often philosophers have appealed to linguistic properties of sentences stating existence. However, the appeal to linguistic intuitions has generally not been systematic and without serious regard of relevant issues in linguistic semantics. This paper has two aims. On the one hand, it will look at statements of existence from a systematic linguistic point of view, in order to try to clarify what the actual semantics of such statements in fact is. (...) On the other hand, it will explore what sort of ontology such statements reflect. The first aim is one of linguistic semantics; the second aim is one of descriptive metaphysics. Philosophically, existence statements appear to reflect the distinction between endurance and perdurance as well as particular notions of abstract states and of kinds. Linguistically, statements of existence involve a particular way of drawing the distinction between eventive and stative verbs and between individual-level and stage-level predicates as well as a particular approach to the semantics of bare plurals and mass nouns. (shrink)

In this paper I argue that adopting a perdurance view of persistence through time does not lead to skepticism about moral responsibility, despite what many theorists have thought.

Worlds, Lewis says this: Let us say that something persists iff, somehow or other, it exists at various times; this is the neutral word. Something perdures iff it persists by having different temporal parts, or stages, at different times, though no one part of it is wholly present at more than one time; whereas it endures iff it persists by being wholly present at more than one time. Perdurance corresponds to the way a road persists through space; part of it (...) is here, and part of it is there, and no part is wholly present at two different places. Endurance corresponds to the way a universal, if there are such things, would be wholly present wherever and whenever it is instantiated. Endurance involves overlap: the content of two different times has the enduring thing as a common part. Perdurance does not.1 Lewis's remarks suggest the following formulations of the two views in the 3D/4D controversy.2.. (shrink)

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)

Are a material object, such as a statue, and its constituting matter, the clay, parts of one another? One wouldn't have thought so, and yet a number of philosophers have argued that they are. I review the arguments for this surprising claim showing how they all fail. I then consider two arguments against the view concluding that there are both pre-theoretical and theoretical considerations for denying that the statue and the clay are mutual parts.

Four-dimensionalism and eternalism are theories on time, change, and persistence. Christian philosophers and theologians have adopted four-dimensional eternalism for various reasons. In this paper I shall attempt to argue that four-dimensional eternalism conflicts with Christian thought. Section I will lay out two varieties of four-dimensionalism—perdurantism and stage theory—along with the typically associated ontologies of time of eternalism and growing block. I shall contrast this with presentism and endurantism. Section II will look at some of the purported theological benefits of adopting (...) four-dimensionalism and eternalism. Section III will examine arguments against four-dimensional eternalism from the problem of evil. Section IV will argue that four-dimensional eternalism causes problems for Christian eschatology. (shrink)

How do objects persist through time? According to endurantism, objects persist through time and do not have temporal parts. According to the transcendentist version of endurantism, objects exist at times by participating in events that occur at those times. This version of transcendentism offers specific metaphysical and semantical advantages over other versions of endurantism. In this paper, we defend transcendentist endurantism against a series of criticisms that have been recently offered by Kristie Miller.

This paper identifies problems with indexicalism and abverbialism about temporary intrinsic properties, and solves them by disentangling two senses in which a particular may possess a property simpliciter. The first sense is the one identified by adverbialists in which a particular possesses at all times the property as a matter of foundational metaphysical fact regardless of whether it is manifest. The second involves building on adverbialism to produce a semantics for property-manifestation according to which different members of a family of (...) second-order properties of the foundational property are relevant to property manifestation at different times. (shrink)

In this paper I present a new definition of endurance. I argue that the three-dimensionalist ought to adopt a different understanding from the four-dimensionalist, of what it is to have a part simpliciter. With this new understanding it becomes possible to define endurance in a manner that both preserves the central endurantist intuitions, whilst avoiding commitment to any controversial metaphysical theses. Furthermore, since this endurantist definition is a mereological one, there is an elegant symmetry between the definitions of endurance and (...) perdurance in that the theories of three- and four-dimensionalism are both expressed in the language of mereology. Nevertheless, though both definitions are expressed within the same broad language, some of the terms of that language have subtly different meanings within the context of each theory. It is in understanding on the one hand that each theory is essentially a mereological theory and that therefore each shares some underlying theoretical similarities, and yet also that there are some subtle differences in the way each theory understands some of the terms of mereology, that allows us to see clearly what lies at the heart of the debate between these two accounts of persistence. (shrink)

Harold Noonan has recently argued (2003) that one of Lewis’s (1983: 76– 77) arguments for the view that objects persist by perduring is flawed. Lewis’s argument can be divided into two main sections, the first of which attempts to show that it is possible that there exists a world of temporal parts or stages, and the second, which attempts to show that our world is such a world. Noonan claims that there is a flaw in each of these two stages.We (...) argue to the contrary. (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)

The relative merits of standard mereology have received quite a bit of attention in recent years from metaphysicians concerned with the part/whole properties of material objects. A question that has not been pursued to the same degree, however, is what sort of semantic repercussions a commitment to mereological sums in the standard sense might have in particular on the predicted behavior of singular terms and our practices of using such terms to refer to objects. The apparent mismatch between our actual (...) referential practices and the persistence conditions attributed to material objects by the supporters of standard mereology puts these philosophers, other things being equal, at a disadvantage compared to those whose ontology matches more closely the observed behavior of singular terms, as they are commonly used in ordinary discourse. To alleviate this problem, David Lewis leans heavily on his distinction between natural and non-natural properties. I argue in this paper that Lewis’ already heavily burdened natural/non-natural distinction among properties is not enough to avoid Quinean indeterminacy for singular terms. Those who are in the business of giving an analysis of constructions involving full-fledged predication, as opposed to the mere spatial overlap of denotations, will thus want to go in for an ontology that places more stringent structural constraints on the referents of singular terms than would be supplied by standard mereology. (shrink)

In this paper I consider an objection that friends of the Metaphysic of Temporal Parts (MTP) press against other solutions to the problem of temporary intrinsics and turn it against the MTP itself. I do not argue that the MTP must be false, nor do I argue that there are no arguments in favor of the MTP. Rather, the conclusion I draw is conditional: if the MTP provides an adequate response to the problem of temporary intrinsics, then the MTP provides (...) no reason to reject our commonsense view of the nature of material objects. (shrink)

How to reconcile monadic simplicity with the successive plurality of the monadic states ? The doctrine of continued creation seems to entail the existence of independent temporal parts and thus lead to the thesis that the world contains only transitory things. I try to show how Leibniz has the resources to get out of this quandary. The analysis of the concept of extension shows that a plurality of states does not constitute a divisible aggregate. Then I examine the Leibnizian interpretation (...) of continued creation, by com- paring it to the scholastic and Cartesian Background. From thence I conclude that Leibniz’s final thesis is that monads are wholly present at each moment of their duration. (shrink)

In this paper, I explore the question what a continuant is, in the context of a very interesting suggestion recently made by Rowland Stout, as part of his attempt to develop a coherent ontology of processes. Stout claims that a continuant is best thought of as something that primarily has its properties at times, rather than atemporally—and that on this construal, processes should count as continuants. While accepting that Stout is onto something here, I reject his suggestion that we should (...) accept that processes are both occurrents and continuants; nothing, I argue, can truly occur or happen, which does not have temporal parts. I make an alternative suggestion as to how one might deal with the peculiar status of processes without jettisoning a very natural account of occurrence; and assess the consequences for the category of continuant. (shrink)

Four dimensionalism, the thesis that persisting objects are four dimensional and thus extended in time as well as space, has become a serious contender as an account of persistence. While many four dimensionalists are mereological universalists, there are those who find mereological universalism both counterintuitive and ontologically profligate. It would be nice then, if there was a coherent and plausible version of four dimensionalism that was non-universalist in nature. I argue that unfortunately there is not. By its very nature four (...) dimensionalism embraces theses about the nature of objects and their borders that make any version of non-universalist four dimensionalism either incoherent or at least highly implausible. (shrink)

We aim to provide the ontological grounds for an adequate account of persistence. We defend a perspectivalist, or moderate pluralist, position, according to which some aspects of reality can be accounted for in ontological terms only via partial and mutually complementary ontologies, each one of which captures some relevant aspect of reality. Our thesis here is that this is precisely the sort of ontological account that is needed for the understanding of persistence, specifically an account involving two independent ontologies, one (...) for continuants, and one for occurrents. (shrink)

The terms `endurance' and `perdurance' are commonly thought to denote distinct ways for an object to persist, but it is surprisingly hard to say what these are. The common approach, defining them in terms of temporal parts, is mistaken, because it does not lead to two coherent philosophical alternatives: endurance so understood becomes conceptually incoherent, while perdurance becomes not just true but a conceptual truth. Instead, we propose a different way to articulate the distinction, in terms of identity rather than (...) temporal parts: an object endures if its identity is determined at every moment at which it exists. We make precise what it means for the identity of an object to be determined at a moment. We also discuss what role the endurance / perdurance distinction, so understood, should play in the debates about time, material objects and personal identity. (shrink)

Plenitude, roughly, the thesis that for any non-empty region of spacetime there is a material object that is exactly located at that region, is often thought to be part and parcel of the standard Lewisian package in the metaphysics of persistence. While the wedding of plentitude and Lewisian four-dimensionalism is a natural one indeed, there are a hand-full of dissenters who argue against the notion that Lewisian four-dimensionalism has exclusive rights to plentitude. These ‘promiscuous’ three-dimensionalists argue that a temporalized version (...) of plenitude is entirely compatible with a three-dimensional ontology of enduring entities. While few would deny the coherence of such a position, and much work has been done by its proponents to appease critics, there has been surprisingly little by way of exploring the various forms such an ontology might take as well as the potential advantages of one plenitudinous three-dimensional ontology over another. Here I develop a novel form of plenitudinous three-dimensionalism, what John Hawthorne (Metaphysical essays, 2006a, b) has called “Neo-Aristotelian Plenitude,” and argue that if one is inclined to endorse an abundant three-dimensional ontology, one is wise to opt for a plenitude of accidental unities. (shrink)

Let’s begin with a simple example. Consider two quarks: one near the tip of your nose, the other near the center of Alpha Centauri. Here is a question about these two subatomic particles: Is there an object that has these two quarks as its parts and that has no other parts? According to one view of the matter (a view that is surprisingly endorsed by a great many contemporary philosophers), the answer to this question is Yes. But I think it (...) is fair to say that according to common sense, the answer to this question is really No, there is no object that has as its only two parts a quark near the tip of your nose and another quark near the center of Alpha Centauri. (shrink)

Let’s start with compositional pluralism. Elsewhere I’ve defended compositional pluralism, which we can provisionally understand as the doctrine that there is more than one basic parthood relation. (You might wonder what I mean by “basic”. We’ll discuss this in a bit.) On the metaphysics I currently favor, there are regions of spacetime and material objects, each of which enjoy bear a distinct parthood relation to members of their own kind. Perhaps there are other kinds of objects that enjoy a kind (...) of parthood relation other than the ones enjoyed by material objects and regions of spacetime. Perhaps, for example, there are facts; I’ve been wavering over whether to embrace these entities for years now. However, I’m reasonably confident that if there are facts than the kind of parthood relation that facts bear to that which composes them is not the kind of parthood relation enjoyed by material objects or regions of spacetime. More on why I am reasonably confident later. (shrink)

In this article, I am interested in four versions of what is often referred to as "the Humphrey objection". This objection was initially raised by Kripke against Lewis's modal counterpart theory, so this is where I will start the discussion. As we will see, there is a perfectly good answer to the objection. I will then examine other places where a similar objection can be raised: it can arise in the case of temporal counterpart theory (in fact, it can arise (...) in the case of all kinds of counterpart theories, independently on modal realism), and a very similar worry can also arise against modal realism itself or against an ersatzist theory of possible worlds itself. For similar reasons, in similar situations, a similar objection will arise. What is interesting is that it is not the case that a similar response can be given in all of these similar cases. So, in the end, we will see what dissimilarities there are and how and why they are relevant. In particular, we will see the differences there are between alethic modalities and temporal modalities. In the case of alethic modalities (metaphysical necessity and possibility), the objection can be answered by appealing to the notion of representation, while this does not work very well in the case of temporal modalities. (shrink)

A brief introductory note to the Monist issue on "Temporal Parts", setting the background for the eight papers included in the rest of the issue (by Y. Balashov, B. Brogaard, K. Fine, M. Heller, R. LePoidevin, J. Parsons, P. M. Simons, and P. van Inwagen).

A critical survey of the main metaphysical theories concerning the nature of material objects (substratum theories, bundle theories, substance theories, stuff theories) and their identity conditions, both synchronic (monist vs. pluralist theories) and diachronic (three-dimensionalism, four-dimensionalism, sequentialism).

I argue that the conjunction of perdurantism (the view that objects are temporally extended) and universalism (the thesis that any old class of things has a mereological fusion) gives rise to undesired complications when combined with certain plausible assumptions concerning the semantics of tensed statements.

We propose an ontological theory that is powerful enough to describe both complex spatio-temporal processes and the enduring entities that participate therein. For this purpose we introduce the notion a directly depicting ontology. Directly depicting ontologies are based on relatively simple languages and fall into two major categories: ontologies of type SPAN and ontologies of type SNAP. These represent two complementary perspectives on reality and employ distinct though compatible systems of categories. A SNAP (snapshot) ontology comprehends enduring entities such as (...) organisms, geographic features, or qualities as they exist at some given moment of time. A SPAN ontology comprehends perduring entities such as processes and their parts and aggregates as they unfold themselves through some temporal interval. We give an axiomatic account of the theory of directly depicting ontologies and of the core parts of the metaontological fragment within which they are embedded. (shrink)

John Perry has argued that language, thought and experience often contain unarticulated constituents. I argue that this idea holds the key to explaining away the intuitive appeal of the A-theory of time and the endurance theory of persistence. The A-theory has seemed intuitively appealing because the nature of temporal experience makes it natural for us to use one-place predicates like past to deal with what are really two-place relations, one of whose constituents is unarticulated. The endurance view can be treated (...) in a similar way; the temporal boundaries of temporal parts of objects are unarticulated in experience and this makes it seem that the very same entity exists at different times. (shrink)