The purpose of this paper is to test the contemporary concept of biological species against some of the problems caused by treating species as spatiotemporally extended entities governed by criteria of persistence, identity, etc. After outlining the general problem of symmetric division in natural objects, I set out some useful distinctions (section 1) and confirm that species are not natural kinds (section 2). Section 3 takes up the separate issue of species definition, focusing on the Biological Species Concept (BSC). Sections (...) 4 and 5 examine the matter of species identity over space and time respectively, as determined by the BSC. Both gradualistic and punctuated equilibrium models of speciation are discussed. In section 6 I argue that the BSC fails to determine adequate criteria for dealing with certain kinds of speciation. Section 7 moves speculatively beyond the BSC to a brief examination of alternatives. (shrink)

When does a human being begin to exist? We argue that it is possible, through a combination of biological fact and philosophical analysis, to provide a definitive answer to this question. We lay down a set of conditions for being a human being, and we determine when, in the course of normal fetal development, these conditions are first satisfied. Issues dealt with along the way include: modes of substance-formation, twinning, the nature of the intra-uterine environment, and the nature of the (...) relation between fetus and mother (connection, parthood, dependence). (shrink)

André Gallois’s Occasions of Identity injects a refreshing new perspective into an old debate. Actually, what is new is the advocacy of the perspective: Gallois takes up a view that many consider a non-starter, and shows this reaction to be premature. The debate is over the right way to understand the traditional puzzles involving two things being in the same place at the same time; the perspective is that identity can hold temporarily. Suppose an amoeba, name it AMOEBA, divides in (...) two. One of the resultant amoebas, POND, lives in a pond; the other, SLIDE, is examined on a slide in a laboratory. Does AMOEBA survive this process, and if so, does it survive as POND or SLIDE? If we stipulate that POND and SLIDE are symmetrically related to AMOEBA then it seems arbitrary to identify AMOEBA with exactly one of POND and SLIDE. But we cannot identify AMOEBA with each, for then by the transitivity and symmetry of identity we would wrongly identify POND and SLIDE. We are left with the conclusion that AMOEBA is identical to neither. But this seems wrong too; surely fission does not result in death. So just what does happen to AMOEBA? How to respond to this and related cases has been much discussed.1 There are many proposals, each with distinctive strengths and weaknesses. To these Gallois adds his own, which runs as follows. After division, there are two amoebas, POND and SLIDE, each of which existed before division. But it does not follow that there were two amoebas before division. Though POND and SLIDE are numerically distinct after division, they were numerically identical before division. The identity relation can hold temporarily, or occasionally, as Gallois puts it. My sense is that this sort of claim is regarded by most metaphysicians as downright wacky. And yet there is something very natural about it. Why distinguish POND and SLIDE today because they will differ tomorrow? I suspect the “wackiness” reaction has two sources, one based on Leibniz’s Law.. (shrink)

Some philosophers believe that everyday objects are 4-dimensional spacetime worms, that a person (for example) persists through time by having temporal parts, or stages, at each moment of her existence. None of these stages is identical to the person herself; rather, she is the aggregate of all her temporal parts.1 Others accept “three dimensionalism”, rejecting stages in favor of the notion that persons “endure”, or are “wholly present” throughout their lives.2 I aim to defend an apparently radical third view: not (...) only do I accept person stages; I claim that we are stages.3 Likewise for other objects of our everyday ontology: statues are statue-stages, coins are coin-stages, etc. At one level, I accept the ontology of the worm view. I believe in spacetime worms, since I believe in temporal parts and aggregates of things I believe in. I.. (shrink)

What makes an object the same persisting individual over time? Philosophers and psychologists have both grappled with this question, but from different perspectives—philosophers conceptually analyzing the criteria for object persistence, and psychologists exploring the mental mechanisms that lead us to experience the world in terms of persisting objects. It is striking that the same themes populate explorations of persistence in these two very different fields—e.g. the roles of spatiotemporal continuity, persistence through property change, and cohesion violations. Such similarities may reflect (...) an underlying connection, in that psychological mechanisms of object persistence (especially relevant parts of mid-level visual object processing) may serve to underlie the intuitions about persistence that fuel metaphysical theories. This would be a way for cognitive science to join these two disparate fields, helping to explain the possible origins and reliability of some metaphysical intuitions, and perhaps leading to philosophical progress. (shrink)

Counterpart theory is often advertised by its track record at solving metaphysical puzzles. Here I focus on puzzles of occasional identity, wherein distinct individuals at one world or time appear to be identical at another world or time. To solve these puzzles, the usual interpretation rules of counterpart theory must be extended beyond the simple language of quantified modal logic. I present a more comprehensive semantics that allows talking about specific times and worlds, that takes into account the multiplicity and (...) sortal-dependence of counterpart relations, and that does not require names to denote actual or present individuals. In addition, the semantics I defend does not identify ordinary individuals with world-bound or time-bound stages and thereby avoids the most controversial aspect of counterpart theory. Humphrey’s counterpart at other worlds or times is none other than Humphrey himself. (shrink)

What happens to a person in a case of fission? Does it survive? Does it go out of existence? Or is the outcome indeterminate? Since each description of fission based on the persistence conditions associated with our ordinary concept of a person seems to clash with one or more platitudes of common sense about the spatiotemporal profile of macroscopic objects, fission threatens the common-sense conception of persons with inconsistency. Standard responses to this paradox agree that the common-sense conception of persons (...) is unstable, differing over which part of the conception requires revision. I will show that this entrenched view of fission is not compulsory. I will develop a solution to the paradox that maintains the consistency of the common-sense conception of persons on the basis of an ontology of persons and other ordinary objects as double-layered compounds. Each of various descriptions of the outcome of personal fission is compatible with principles about the spatiotemporal profile of persons, because the descriptions and the principles manifest different perspectives on persons and are made true or false by different ontological components of the latter. What holds for the fission of persons, holds for the fission of other kinds of objects. (shrink)

(No abstract is available for this citation).

Two of the main contenders in the debate about personal persistence over time are the neo-Lockean psychological continuity view and animalism as defended by Olson and Snowdon. Both are wrong. The position I shall argue for, which I call, following Olson, the hybrid view, takes psychological continuity as a sufficient but, pace the neo-Lockeans, not necessary condition for personal persistence. It sides with the animalist in allowing that mere biological continuity is also sufficient. So I am, in a sense, a (...) psychological continuity theorist. But I am also in a sense, a biological theorist. (shrink)

Jacob Ross argues that the fission cases discussed in the personal identity literature cannot be accommodated without rejecting basic intuitions of everyday ethical thinking. He notes that many philosophers have responded to the challenge of fission ‘by rejecting the metaphysical assumptions on which it rests’. In particular, that many have denied that in fission one ceases to exist. He contends that these denials do not meet the challenge to commonsense ethical thinking. I reject these claims. One of the metaphysical views (...) he considers is the multiple occupancy view of Lewis and Robinson, according to which in fission there are all along two numerically distinct, initially collocated, persons. I claim that Ross has not shown that this view has counterintuitive ethical implications. (shrink)

I argue that perceptual content is always affected by the allocation of one’s attention. Perception attributes determinable and determinate properties to the perceived scene. Attention makes (or tries to make) our perceptual attribution of properties more determinate. Hence, a change in our attention changes the determinacy of the properties attributed to the perceived scene.

A radical metaphysical theory typically comes packaged with a semantic theory that reconciles those radical claims with common sense. The metaphysical theory says what things exist and what their natures are, while the semantic theory specifies, in terms of these things, how we are to interpret everyday language. Thus may we “think with the learned, and speak with the vulgar.” This semantic accommodation of common sense, however, can end up undermining the very theory it is designed to protect. This paper (...) is a case study, showing in detail how one popular version of temporal parts theory is self-undermining. This raises the specter that the problem generalizes to other metaphysical theories. (shrink)

Puzzles about persistence and change through time, i.e., about identity across time, have foundered on confusion about what it is for ‘two things’ to be have ‘the same thing’ at a time. This is most directly seen in the dispute over whether material objects can occupy exactly the same place at the same time. This paper defends the possibility of such coincidence against several arguments to the contrary. Distinguishing a temporally relative from an absolute sense of ‘the same’, we see (...) that the intuition, ‘this is only one thing’, and the dictum, ‘two things cannot occupy the same place at the same time’, are individuating things at a time rather than absolutely and are therefore compatible with coincidence. Several other objections philosophers have raised ride on this same ambiguity. Burke, originating what has become the most popular objection to coincidence, argues that if coincidence is possible there would be no explanation of how objects that are qualitatively the same at a time could belong to different sorts. But we can explain an object’s sort by appealing to its properties at other times. Burke’s argument to the contrary equivocates on different notions of ‘cross-time identity’ and ‘the statue’. From a largely negative series of arguments emerges a positive picture of what it means to say multiple things coincide and of why an object’s historical properties explain its sort rather than vice versa – in short, of how coincidence is possible. (shrink)

The fission of a person involves what common sense describes as a single person surviving as two distinct people. Thus, say most metaphysicians, this paradox shows us that common sense is inconsistent with the transitivity of identity. Lewis’s theory of overlapping persons, buttressed with tensed identity, gives us one way to reconcile the common sense claims. Lewis’s account, however, implausibly says that reference to a person about to undergo fission is ambiguous. A better way to reconcile the claims of common (...) sense, one that avoids this ambiguity, is to recognize branching persons, persons who have multiple pasts or futures. (shrink)

I argue that two competing accounts of persistence, three and four dimensionalism, are in fact metaphysically equivalent. I begin by clearly defining three and four dimensionalism, and then I show that the two theories are intertranslatable and equally simple. Through consideration of a number of different cases where intuitions about persistence are contradictory, I then go on to show that both theories describe these cases in the same manner. Further consideration of some empirical issues arising from the theory of special (...) relativity lead me to conclude that the two theories are equally explanatory, and thus finally that they are metaphysically equivalent. (shrink)

It is possible to wholly exist at multiple spatial locations at the same time. At least, if time travel is possible and objects endure, then such must be the case. To accommodate this possibility requires the introduction of a spatial analog of either relativising properties to times—relativising properties to spatial locations—or of relativising the manner of instantiation to times—relativising the manner of instantiation to spatial locations. It has been suggested, however, that introducing irreducibly spatially relativised or spatially adverbialised properties presents (...) some difficulties for the endurantist. I will consider an objection according to which embracing such spatially relativised properties could lead us to reject mereology altogether in favour of a metaphysics according to which objects are wholly present at every space-time point at which they exist. I argue that although such a view is coherent, there are some good reasons to reject it. Moreover, I argue that the endurantist can introduce spatially relativised or adverbialised properties without conceding that objects lack spatial parts. Such a strategy has the additional advantage that it allows the endurantist not only to explain time travel, but also to reconcile our competing intuitions about cases of fission. (shrink)

It is possible to wholly exist at multiple spatial locations at the same time. At least, if time travel is possible and objects endure, then such must be the case. To accommodate this possibility requires the introduction of a spatial analog of either relativising properties to times—relativising properties to spatial locations—or of relativising the manner of instantiation to times—relativising the manner of instantiation to spatial locations. It has been suggested, however, that introducing irreducibly spatially relativised or spatially adverbialised properties presents (...) some difficulties for the endurantist. I will consider an objection according to which embracing such spatially relativised properties could lead us to reject mereology altogether in favour of a metaphysics according to which objects are wholly present at every space-time point at which they exist. I argue that although such a view is coherent, there are some good reasons to reject it. Moreover, I argue that the endurantist can introduce spatially relativised or adverbialised properties without conceding that objects lack spatial parts. Such a strategy has the additional advantage that it allows the endurantist not only to explain time travel, but also to reconcile our competing intuitions about cases of fission. (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 (i) for any arbitrary set S of instantaneous simples that exist at the same instant, there exists a fusion of the members of S, and (ii) 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)

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)

David Lewis's cohabitation theory suffered damaging criticism from Derek Parfit. Though many have defended versions of Lewis's theory Parfit's criticism has not been answered. This paper shows how to defend the cohabitation theory against Parfit's criticism.

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.

According to the cohabitation account, all the persons that result from a fission event cohabit the same body prior to fission. This article concerns a problem for this account. Suppose Manuel and Jimena are suffering from an equally painful migraine. Unlike Jimena, however, Manuel will undergo fission. Assuming you have a spare painkiller, whom should you give it to? Intuitively, you have no more reason to give it to one or the other. The problem is that the cohabitation account suggests (...) otherwise. According to the account, there are two persons cohabiting Manuel’s body, in which case you should arguably give them the pill, since doing so alleviates the pain of more beings. One response argues that the two persons cohabiting Manuel’s body share one pain. Thus, giving them the pill alleviates no more pain than giving it to Jimena, and therefore you have no more reason to do one or the other. The goal of this article is to show that this response fails. (shrink)

According to the cohabitation account, all the persons that result from a fission event cohabit the same body prior to fission. This article concerns a problem for this account. Suppose Manuel and Jimena are suffering from an equally painful migraine. Unlike Jimena, however, Manuel will undergo fission. Assuming you have a spare painkiller, whom should you give it to? Intuitively, you have no more reason to give it to one or the other. The problem is that the cohabitation account suggests (...) otherwise. According to the account, there are two persons cohabiting Manuel’s body, in which case you should arguably give them the pill, since doing so alleviates the pain of more beings. One response argues that the two persons cohabiting Manuel’s body share one pain. Thus, giving them the pill alleviates no more pain than giving it to Jimena, and therefore you have no more reason to do one or the other. The goal of this article is to show that this response fails. (shrink)

Through careful analysis of a specific example, Parfit’s ‘fission argument’ for the unimportance of personal identity, I argue that our judgements concerning imaginary scenarios are likely to be unreliable when the scenarios involve disruptions of certain contingent correlations. Parfit’s argument depends on our hypothesizing away a number of facts which play a central role in our understanding and employment of the very concept under investigation; as a result, it fails to establish what Parfit claims, namely, that identity is not what (...) matters. I argue that Parfit’s conclusion can be blocked without denying that he has presented an imaginary case where prudential concern would be rational in the absence of identity. My analysis depends on the recognition that the features that explain or justify a relation may be distinct from the features that underpin it as necessary conditions. (shrink)

There is a well-known argument from Leibniz's Law for the view that coincident material things may be distinct. For given that they differ in their properties, then how can they be the same? However, many philosophers have suggested that this apparent difference in properties is the product of a linguistic illusion; there is just one thing out there, but different sorts or guises under which it may be described. I attempt to show that this ‘opacity’ defence has intolerable consequences for (...) the functioning of our language and that the original argument should therefore be allowed to stand. (shrink)

How do groups of people persist through time? Groups can change their members, locations, and structure. In this paper, I present puzzles of persistence applied to social groups. I first argue that four-dimensional theories better explain the context sensitivity of how groups persist. I then exploit two unique features of the social to argue for the stage theory of group persistence in particular. First, fusion and fission cases actually happen to social groups, and so cannot be marginalized as “pathological.” Second, (...) it is implausible that groups spatially coincide pre-fission. This means that theories that depend on pre-fission spatial coincidence, such as some endurance theories and the worm theory, cannot explain fission cases. All things considered, the stage theory offers the best explanation of how groups persist. (shrink)

One reading of the Doctrine of Original Sin has it that we are guilty of a sin committed by Adam, thousands of years ago. Fission theorists account for this by saying that Adam fissioned after he sinned and that each of us is one of his ‘fission successors’. This paper recaps the current discussion in the literature about this theory, arguing that the proposed version does not work for reasons already raised by Rea and Hudson. I then introduce a new (...) version of fission theory that avoids the Rea-Hudson objection. (shrink)

The Christian doctrine of the Trinity poses a serious philosophical problem. On the one hand, it seems to imply that there is exactly one divine being; on the other hand, it seems to imply that there are three. There is another well-known philosophical problem that presents us with a similar sort of tension: the problem of material constitution. We argue in this paper that a relatively neglected solution to the problem of material constitution can be developed into a novel solution (...) to the problem of the Trinity. (shrink)

One of the standard approaches to the metaphysics of personal identity has some counter-intuitive ethical consequences when combined with maximising consequentialism and a plausible doctrine about aggregation of consequences. This metaphysical doctrine is the so-called ‘multiple occupancy’ approach to puzzles about fission and fusion. It gives rise to a new version of the ‘utility monster’ problem, particularly difficult problems about infinite utility, and a new version of a Parfit-style ‘repugnant conclusion’. While the article focuses on maximising consequentialism for simplicity, the (...) problems demonstrated apply more widely to a range of ethical views, especially flavours of consequentialism. This article demonstrates how these problems arise, and discusses a number of options available in the light of these problems for a consequentialist tempted by a multiple occupancy metaphysics. (shrink)

One of the standard approaches to the metaphysics of personal identity has some counter‐intuitive ethical consequences when combined with maximising consequentialism and a plausible (though not uncontroversial) doctrine about aggregation of consequences. This metaphysical doctrine is the so‐called ‘multiple occupancy’ approach to puzzles about fission and fusion. It gives rise to a new version of the ‘utility monster’ problem, particularly difficult problems about infinite utility, and a new version of a Parfit‐style ‘repugnant conclusion’. While the article focuses on maximising consequentialism (...) for simplicity, the problems demonstrated apply more widely to a range of ethical views, especially flavours of consequentialism. This article demonstrates how these problems arise, and discusses a number of options available in the light of these problems for a consequentialist tempted by a multiple occupancy metaphysics. (shrink)

The paper defends a combination of perdurantism with mereological universalism by developing semantics of temporary predications of the sort ’some P is/was/will be (a) Q’. We argue that, in addition to the usual application of causal and other restrictions on sortals, the grammatical form of such statements allows for rather different regimentations along three separate dimensions, according to: (a) whether ‘P’ and ‘Q’ are being used as phase or substance sortal terms, (b) whether ‘is’, ‘was’, and ‘will be’ are the (...) ‘is’, ‘was’, ‘will be’ of identity or of constitution, and (c) whether ‘Q’ is being used as a subject or predicate term. We conclude that this latitude is beneficial, as it conforms with linguistic reality (i.e., the multiple uses actually in place) and also enables one to turn what is ordinarily perceived as a problem for universalist perdurantism viz., a commitment to all sorts of weird and gerrymandered temporally extended entities, into an advantage, for the richness in questions allows us to make sense of. (shrink)

Meta-ontology (in van Inwagen's sense) concerns the methodology of ontology, and a controversial meta-ontological issue is to what extent ontology can rely on linguistic analysis while establishing the furniture of the world. This paper discusses an argument advanced by some ontologists (I call them unifiers) against supporters of or coincident entities (I call them multipliers) and its meta-ontological import. Multipliers resort to Leibniz's Law to establish that spatiotemporally coincident entities a and b are distinct, by pointing at a predicate F (...) () made true by a and false by b . Unifiers try to put multipliers in front of a dilemma: in attempting to introduce metaphysical differences on the basis of semantic distinctions, multipliers either (a) rest on a fallacy of verbalism, entailed by a trade-off between a de dicto and a de re reading of modal claims, or (b) beg the question against unifiers by having to assume the distinction between a and b beforehand. I shall rise a tu quoque, showing that unifiers couldn't even distinguish material objects (or events) from the spatiotemporal regions they occupy unless they also resorted to linguistic distinctions. Their methodological aim to emancipate themselves from linguistic analysis in ontological businesses is therefore problematic. (shrink)

This paper distinguishes bruteness from fundamentality by developing a theory of stochastic grounding that makes room for non-fundamental bruteness. Stochastic grounding relations, which only underwrite incomplete explanations, arise when the fundamental level underdetermines derivative levels. The framework is applied to fission cases, showing how one can break symmetries and mitigate bruteness whilst avoiding arbitrariness and hypersensitivity.

As regards the question of what matters in survival two views have been identified: on the one hand, we have the view that what matters is identity (the so-called ?commonsense view?) and, on the other hand, we have the view that what matters is the holding of certain psychological connections between various mental states over time (the relation R). Several attempts have tried to reconcile these two views involving the so-called ?multiple occupancy view? or ?cohabitation thesis?. Even if the latter (...) comes in several formulations, common elements are, positing the appropriateness of a description of the fission case according to which the post-fission persons existed prior to fission and also, that what determines that two persons who exist at a certain time are distinct can be facts about what is the case at other times. The paper discusses three of the most influential formulations of the multiple occupancy view, which intend to reconcile identity with what matters, and argues that for various reasons these at least do not work in this regard. (shrink)

Pluralists about coincident entities say that distinct entities may be spatially coincident throughout their entire existence. The most pressing issue they face is the grounding problem. They say that coincident entities may differ in their persistence conditions and in the sortals they fall under. But how can they differ in these ways, given that they share all their microphysical properties? What grounds those differences, if not their microphysical properties? Do those differences depend only on the way we conceptualise those objects? (...) Are they primitive facts about reality? Neither option is pleasant for the pluralist, but what else can she say? To respond to the grounding problem, the pluralist should first tell a story about what material objects are. If that story explains how the modal and sortal properties of objects are grounded, in a way that allows for differences between coincident objects, then she has a response to the problem. That is precisely my aim in this paper. (shrink)

I introduce a new approach to fission puzzles called the Diversified Approach that proceeds by distinguishing different kinds of fission and assimilating each kind to a different ordinary phenomenon, such as breaking apart, replication, or part loss. To illustrate this approach, I apply it to the case of amoebic fission. The upshot is a novel account of amoebic fission according to which the dividing amoeba ceases to exist because it breaks apart. After developing this solution and highlighting some of its (...) advantages, I discuss briefly how the Diversified Approach can be extended to other varieties of fission. (shrink)

An encyclopedia entry which covers various revisionary conceptions of which macroscopic objects there are, and the puzzles and arguments that motivate these conceptions: sorites arguments, the argument from vagueness, the puzzles of material constitution, arguments against indeterminate identity, arguments from arbitrariness, debunking arguments, the overdetermination argument, and the problem of the many.

Traditionally, this puzzle has been solved in various ways. Aristotle, for example, distinguished between “accidental” and “essential” changes. Accidental changes are ones that don't result in a change in an objects' identity after the change, such as when a house is painted, or one's hair turns gray, etc. Aristotle thought of these as changes in the accidental properties of a thing. Essential changes, by contrast, are those which don't preserve the identity of the object when it changes, such as when (...) a house burns to the ground and becomes ashes, or when someone dies. Armed with these distinctions, Aristotle would then say that, in the case of accidental changes, (1) and (2) are both false—a changing thing can really change one of its “accidental properties” and yet literally remain one and the same thing before and after the change. (shrink)

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.

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

Here I develop an account of our persistence that accommodates each of the following compelling intuitions: (i) that we are animals, (ii) that we existed prior to the onset of whatever psychological capacities are necessary for personhood, and we can continue to exist with the loss of those and other psychological capacities, (iii) that with suitable psychological continuity, the person goes with the brain/cerebrum in remnant person and brain/cerebrum transplant cases, and (iv) that it is possible for us to survive (...) gradual large-scale replacement of organic with inorganic parts. With the help of a couple of recent “hybrid” animalist accounts I develop an analysis of our persistence that entails (ii)–(iv) while being consistent with (i). (shrink)

I critically discuss both the particular doctrinal and general meta-philosophical or methodological tenets of Mark Johnston's paper "Human Beings", attending to several weaknesses in his argument. One of the most important amongst them is an apparent reliance on a substitution of identicals within an intensional context as he argues that continuity of functioning brain is essential to the persistence of "Human Beings" as allegedly singled out by his methodology; another equally important is a simple lacuna in place of an argument (...) that candidate entities for re-identification by means we take for granted in the case of persons cannot be what I call "mentalistically" individuated. (shrink)

This is a copy of my DPhil thesis, the abstract for which is as follows: The first third of this thesis argues for a B-theoretic conception of time according to which all times exist equally and the present is in no way privileged. I distinguish "ontological" A-theories from "non-ontological" ones, arguing that the latter are experientially unmotivated and barely coherent. With regard to the former, I focus mainly on presentism. After some remarks on how to formulate this (and eternalism) non-trivially, (...) I review the non-relativistic case against presentism. I then consider the impact of Special Relativity on the debate, and attempt to deepen this impact by supplying a modal variation on the standard arguments. The middle third of the thesis investigates persistence, contending that both endurance and perdurance are consonant with the eternalism already endorsed. After introducing these theories of persistence, and discussing in particular how best to formulate an eternalist endurance, I proceed to defend the coherence of this combination. The Problem of Change is addressed here. I then respond in some detail to recent allegations of relativistic threats to endurance. The final third of the thesis questions the validity of the endurantist-perdurantist dispute. I criticize two recently proposed translation schemes that aim to show this dispute to be non-substantive. However, the second scheme suggests a doctrine of "Ontological Equivalence" which I develop and consider. I then address the Rotating Discs Argument, using this to launch a discussion of identity, genidentity, and the relationship between them. (shrink)

Can different material objects have the same parts at all times at which they exist? This paper defends the possibility of such coincidence against the main argument to the contrary, the ‘Indiscernibility Argument’. According to this argument, the modal supervenes on the nonmodal, since, after all, the non-modal is what grounds the modal; hence, it would be utterly mysterious if two objects sharing all parts had different essential properties. The weakness of the argument becomes apparent once we understand how the (...) modal is grounded in the nonmodal. By extending the ideas of combinatorialism so that we recombine haecceities as well as fundamental properties, we see how modal properties can be grounded in non-modal properties in a way that allows coincidence and yet also explains why there are differences in the modal properties of coinciding objects. Despite this, some de re modal facts are not grounded in the non-modal but instead are brute. However, although we cannot explain why a particular object has the basic modal properties it has, we can explain a closely related, semantic fact and, comparing the facts we can’t explain to more familiar brute facts, we understand why there should be no better explanation. As a result, we can see how coincidence is, after all, possible. (shrink)