How many championships have the Lakers won? Fourteen, if one counts those won in Minneapolis; nine, otherwise. Which is the correct answer? Is it even obvious that there is a correct answer? One is tempted to identify a team with its players. But teams, like ordinary objects, seem to survive gradual turnover of their parts. Suppose players from the Lakers are gradually replaced, one by one, over the years. We have the intuition that the team persists through this change, even (...) after none of the original players remain. Suppose too that these original players wind up playing for the Celtics. Lakers fans face an awkward question: for whom should they root? On the one hand, they have the team currently playing in L.A.—a team that has continued gradually through the years, who wear the same uniforms, but now can’t make the playoffs. On the other hand, there are the beloved Lakers starting five (responsible for all those championships) now playing together in the hated Boston garden—a team which looks (despite wearing those hated Celtics jerseys) and plays just like the Lakers of old. What’s a loyal fan to do? (shrink)

To what extent is time similar to space? in this paper it is shown that the claim, Made by richard taylor among others, That time and space are "radically alike" is unfounded. This claim can be supported only by employing the notion of temporal parts. It is shown that if objects are regarded as having temporal parts as well as spatial parts, Then serious disanalogies exist between time and space. Furthermore, If objects are said to have temporal parts, Then it (...) must also be held that time is in a very important sense "prior" to space and this that time and space are not only unlike in certain respects but indeed are radically dissimilar. Moreover, The so-Called "manifold theory of time" necessarily makes use of the notion of temporal parts and therefore should hold that time and space are quite unlike. But since an important part of the manifold theory of time is the claim that time and space are very much alike, This theory is to that extent not satisfactory. (shrink)

Like most theories in first order metaphysics, theories of persistence generally aim at metaphysically necessary truth. Consequently, those that accept proper temporal parts of material entities are maximally competitive only when they accord with the full range of metaphysically possible temporal mereological structures. Consider, for example, a structure in which every element is a proper temporal part of some others. The present essay argues that temporal junk plausibly is possible and that perdurantism, the thesis that material entities persist by having (...) distinct proper temporal parts at distinct times, does not accord with it. The essay then outlines a novel four-dimensionalist theory of persistence that accommodates junk. On this theory, material entities persist not in virtue of possessing proper temporal parts, but rather in virtue of being grounded by certain pluralities of fundamental property instances over their careers, and by sub-pluralities thereof over corresponding sub-intervals of their careers. Accordingly, this way of persisting is dubbed ‘plurdurance’. (shrink)

In ‘Location and Perdurance’ (2010), I argued that there are no compelling mereological or sortal grounds requiring the perdurantist to distinguish the molecule Abel from the atom Abel in Gilmore’s original case (2007). The remaining issue Gilmore originally raised concerned the ‘mass history’ of Adam and Abel, the distribution of ‘their’ mass over spacetime. My response to this issue was to admit that mass histories needed to be relativised to a way of partitioning the location of Adam/Abel, but that did (...) not amount to relativising any fundamental natural intrinsic properties—the latter are all had unrelativised, and (so most perdurantists would say). (shrink)

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)

in D. Dieks (ed.), The Ontology of Spacetime, Vol. 2. Elsevier, forthcoming.