Sider (2001) and Hawley (2001) argue that, in order to account for the mere possibility of change, temporal parts must be as fine-grained as possible change, and hence as fine-grained as time. However, when dealing with metaphysical possibility, the fine-grainedness of actual time and the fine-grainedness of possible change can come apart. Once this is taken into account, we see that, on certain assumptions about the actual microstructure of time, the modal arguments of Sider and Hawley lead to the problematic claim that temporal parts are more fine-grained than time. The utility of a temporal parts theory thus seems to be sensitive to metaphysically contingent facts concerning the microstructure of time.

Traynor identifies a tension between armchair reasoning telling us about the mereological structure of objects and empirical investigation telling us about the structure of spacetime. Section 1 explains, and bolsters, that tension. Section 2 discusses Traynor’s resolution, and suggests some possible problems with it, whilst Section 3 discusses an alternative.

What formulas are tense-logically valid depends on the structure of time, for example on whether it has a beginning. Logicians have investigatedwhat formulas correspond towhat physical hypotheses about time. Analogously, we can investigate what formulas of modal logic correspond to what metaphysical hypotheses about necessity. It is widely held that physical hypotheses about time may be contingent. If so, tense-logical validity may be contingent. In contrast, validity in modal logic is typically taken to be non-contingent, as reflected by the general acceptance of the so-called ‘‘rule of necessitation.’’ But as has been argued by various authors in recent years, metaphysical hypotheses may likewise be contingent. If, in particular, hypotheses about the extent of possibility are contingent, we should expect modal-logical validity to be contingent too. Let ‘‘contingentism’’ be the view that everything that is not ruled out by logic is possible. I shall investigate what the right system of modal logic is, if contingentism is true. Given plausible assumptions, the system contains the McKinsey principle, and is thus not even contained in S5. It also contains simple and elegant iteration principles for the contingency operator: something is contingent if and only if it is contingently contingent.

In his paper, Leuenberger (2013) discerns two salient conceptions of logical validity. Strikingly, neither of these conceptions involves modality. He goes on to use these conceptions as a framework to explore certain recent investigations in the logic of modality, where he ingeniously articulates and proves interesting theses about the logic of contingentism. While I think there’s much of interest in Leuenberger’s results, and that his conception of de facto validity gives a unified account of philosophers’ talk of the logic of time and modality, in this note I suggest that perhaps he is too hasty to dismiss the modal conception of validity and that, moreover, his concept of de facto validity may be too inclusive.

Until recently, an almost perfect parallelism seemed to hold between theories of identity through time and across possible worlds, as every account in the temporal case (endurantism, perdurantism, exdurantism) was mirrored by a twin account in the modal case (trans-world identity, identity-via-parts, identity-via-counterparts). Nevertheless, in the recent literature, this parallelism has been broken because of the implementation in the debate of the relation of location. In particular, endurantism has been subject to a more in-depth analysis, and different versions of it, corresponding to different ways an entity can be located in time, emerged. In this article, we provide a precise map of the conceptions at stake, complete the debate by introducing a version of endurantism not yet considered in the debate—we call transcendentism—and show that it allows us to provide an effective interpretation of the relation of trans-world identity and an intuitive solution in the temporal case.

Mereological nihilists are faced with a difficult challenge: explaining ordinary talk about material objects. Popular paraphrase strategies involve plurals, arrangements of particles, or fictions. In this paper, a new paraphrase strategy is put forward that has distinct advantages over its rivals: it is compatible with gunk and emergent properties of macro-objects. The only assumption is a commitment to a liberal view of the nature of simples; the nihilist must be willing to accept the possibility of heterogeneous extended simples. The author suggests reinterpreting the parthood and composition relations as modal. According to this paraphrase, composition is a kind of counterpart relation. The author shows that one can accept that mereological nihilism is metaphysically necessary, while endorsing all the claims of classical mereology. As a result, the nihilists are in exactly the same position as the classical mereologist when it comes to explaining talk about ordinary objects, but without the additional ontology.

There are two intuitions about time. The first is that there’s something special about the present that objectively differentiates it from the past and the future. Call this intuition Specialness. The second is that the time at which we happen to live is just one amongmany other times, all of which are ‘on a par’ when it comes to their forming part of reality. Call this other intuition Egalitarianism. Tradition has it that the so-called ‘A-theories of time’ fare well at addressing the first intuition, but rather badly when it comes to the second. The goal of this article is to offer advice to A-theorists about how to reconcile their view with Egalitarianism.

We develop a theory about the metaphysics of time and modality that combines the conceptual resources devised in recent sympathetic work on ontological pluralism (the thesis that there are fundamentally distinct kinds of being) with the thought that what is past, future, and merely possible is less real than what is present and actual (albeit real enough to serve as truthmakers for statements about the past, future, and merely possible). However, we also show that despite being a coherent, distinctive, and prima facie appealing position, the theory succumbs to what we call the ‘‘problem of mixed ontological status’’. We conclude that the proponents of the theory can only evade these problems by developing ontological pluralism in a radically different way than it has been by its recent sympathizers.