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)

Do Russellian propositions have their constituents as parts? One reason for thinking not is that if they did, they would generate apparent counterexamples to plausible mereological principles. As Frege noted, they would be in tension with the transitivity of parthood. A certain small rock is a part of Etna but not of the proposition that Etna is higher than Vesuvius. So, if Etna were a part of the given proposition, parthood would fail to be transitive. As William Bynoe has noted (...) (speaking of facts rather than propositions), they would seem to violate certain supplementation principles. Consider the singular proposition, concerning identity, that it is identical with itself. Given the relevant form of Russellianism, this proposition would have identity as a proper part, but it would not have any parts disjoint from identity, and indeed it would not have even a single pair of disjoint parts, in violation of various supplementation principles. This chapter offers a unified solution to the problems about transitivity and supplementation. One key ingredient in the solution is the view that parthood is a four-place relation expressed by ‘x at y is a part of z at w’. Another key ingredient is the view that the semantic contents of predicates and sentential connectives have ‘slots’ or ‘argument positions’ in them. (Both ingredients are independently motivated elsewhere.) Four-place analogues of the transitivity and supplementation principles are set out, and it is argued that these are not threatened by the examples from Frege and Bynoe. (shrink)

Slot theory is the view that (i) there exist such entities as argument places, or ‘slots’, in universals, and that (ii) a universal u is n-adic if and only if there are n slots in u. I argue that those who take properties and relations to be abundant, fine-grained, non-set-theoretical entities face pressure to be slot theorists. I note that slots permit a natural account of the notion of adicy. I then consider a series of ‘slot-free’ accounts of that notion (...) and argue that each of them has significant drawbacks. (shrink)

Endurantism, the view that material objects are wholly present at each moment of their careers, is under threat from supersubstantivalism, the view that material objects are identical to spacetime regions. I discuss three compromise positions. They are alike in that they all take material objects to be composed of spacetime points or regions without being identical to any such point or region. They differ in whether they permit multilocation and in whether they generate cases of mereologically coincident entities.

I formulate an account, in terms of essence and ground, that explains why atomic Russellian propositions have the truth conditions they do. The key ideas are that (i) atomic propositions are just 0-adic relations, (ii) truth is just the 1-adic version of the instantiation (or, as I will say, holding) relation (Menzel 1993: 86, note 27), and (iii) atomic propositions have the truth conditions they do for basically the same reasons that partially plugged relations, like being an x and a (...) y such that Philip gave x to y, have the holding conditions they do. The account is meant to be mainly of intrinsic interest, but I hope that it goes some distance toward answering an objection to classical theories of propositions put forward by King (2014), who writes that ‘since the classical conception of propositions as things that have truth conditions by their very natures and independently of minds and languages is incapable of explaining how or why propositions have truth conditions, it is unacceptable’ (2014: 47). Propositions do have their truth conditions ‘by their very natures’ and ‘independently of minds and languages’. But a fact about a given entity can hold by the very nature of that entity without being a fundamental fact. I argue that this is plausibly the case for atomic Russellian propositions and the facts about their truth conditions. A fact about the truth conditions of such a proposition holds by the very nature of the given proposition but is metaphysically grounded in facts about that proposition’s parts and their essences. If my account is correct, then the supposedly intractable problem of explaining why the given propositions have the truth conditions they do reduces to the problem of explaining why relations have the holding essences they do, which few seem to have found worrisome . (shrink)

Ned Markosian has recently defended a new theory of composition, which he calls regionalism : some material objects xx compose something if and only if there is a material object located at the fusion of the locations of xx. Markosian argues that regionalism follows from what he calls the subregion theory of parthood. Korman and Carmichael agree. We provide countermodels to show that regionalism does not follow from, even together with fourteen potentially implicit background principles. We then show that regionalism (...) does follow from five of those background principles together with and two additional principles connecting parthood and location, which we call and. While the additional principles are not uncontroversial, our conjecture is that many will find them attractive. We conclude by mentioning that fills a previously unnoticed gap in the formal theory of location presented in Parsons. (shrink)

Personal time, as opposed to external time, has a certain role to play in the correct account of death and immortality. But saying exactly what that role is, and what role remains for external time, is not straightforward. I formulate and defend accounts of death and immortality that specify these roles precisely.

I defend coincidentalism (the view that some pluralities have more than one mereological fusion) and restricted composition (the view that some pluralities lack mereological fusions) against recent arguments due to Theodore Sider.

Speaks defends the view that propositions are properties: for example, the proposition that grass is green is the property being such that grass is green. We argue that there is no reason to prefer Speaks's theory to analogous but competing theories that identify propositions with, say, 2-adic relations. This style of argument has recently been deployed by many, including Moore and King, against the view that propositions are n-tuples, and by Caplan and Tillman against King's view that propositions are facts (...) of a special sort. We offer our argument as an objection to the view that propositions are unsaturated relations. (shrink)

David Lewis defends the following "non-circular definition of personhood": "something is a continuant person if and only if it is a maximal R-interrelated aggregate of person-stages. That is: if and only if it is an aggregate of person-stages, each of which is R-related to all the rest (and to itself), and it is a proper part of no other such aggregate." I give a counterexample, involving a person who is a part of another, much larger person, with a separate mental (...) life. I then offer an easy repair, which preserves the virtues of Lewis's definition without introducing any new vices. (shrink)

A defense of the view that (i) to be alive is to be actively undergoing (not merely capable of undergoing) certain vital processes, that (ii) to die is cease to be capable of undergoing those processes (not to cease undergoing them), and that (iii) organisms in cryptobiosis (suspended animation) are not undergoing those processes but are capable of doing so, and are neither alive nor dead.

I introduce a puzzle about contact and de re temporal predication in relativistic spacetime. In particular, I describe an apparent counterexample to the following principle, roughly stated: if B is never in a position to say ‘I was touching A, I am touching A, and I will be touching A’, then (time travel aside) A is never in a position to say ‘I was touching B, I am touching B, and I will be touching B’. In the case I present, (...) the most that A is ever in a position to say is: ‘I am now touching B, but this is the only instant at which this will ever be so’. B, on the other hand, can say: ‘I was formerly touching A, I am currently touching A, and I will in the future be touching A’. (And neither object is a time traveler.). (shrink)

According to what Barry Dainton calls the 'Strong Introspectibility thesis', it is a necessary truth that mental states S and S* are co-conscious (experienced together) if and only if they are 'jointly introspectible', i.e., if and only if it is possible for there to be some single state of introspective awareness that represents both S and S*. Dainton offers two arguments for the conclusion that joint introspectibility is unnecessary for co-consciousness. In these comments I attempt to show, first, that Dainton's (...) arguments fail, and, second, that joint introspectibility is actually insufficient for co-consciousness. (As to whether it is also unnecessary, I take no stance.). (shrink)