Theodore Sider

Quantifier variantists accept multiple alternative ontological languages in which quantifiers obey the usual inference rules despite having different meanings. But collapse arguments seem to show that these quantifiers would be provably equivalent to one another. Cian Dorr has pushed this discussion forward by formulating the collapse argument in terms of an algebra of meanings that are common amongst the languages. I attempt to show that quantifier variantists can respond. But an important distinction between types of quantifier variance emerges, between those in which quantifier meanings draw on a single objective backbone of “portions of reality,” and those (such as the type that is arguably associated with neo-Fregeanism) in which they do not.

In this chapter the author examines the idea of time's motion, or flow, more carefully, by comparing it to the motion of ordinary objects. Ordinary objects move with respect to time. So if time itself moves, it must move with respect to some other sort of time. But what would that other time be? Most motion takes place with respect to the familiar timeline, but time itself moves with respect to another timeline, hypertime. Hypertime is supposed to be a sort of time. Hypertime must move with respect to yet another sort of time, hyper‐hyper time. Space‐time diagrams can be used to represent all of history; everything that has ever happened or ever will happen can be fit into a space‐ time diagram somewhere. According to the space‐time theory, time and space are analogous in many ways. Finally the author argues against the space‐time theory.

Nonreductive materialism is the dominant position in the philosophy of mind. The global supervenience of the mental on the physical has been thought by some to capture the central idea of nonreductive materialism: that mental properties are ultimately dependent on, but irreducible to, physical properties. But Jaegwon Kim has argued that global psychophysical supervenience does not provide the materialist with the desired dependence of the mental on the physical, and in general that global supervenience is too weak to be an interesting dependence relation. We argue that these arguments are unsound. Along the way, we clarify the relationship between global and strong supervenience, and show clearly what sort of dependence global supervenience provides

Shamik Dasgupta has argued that realists about natural properties (and laws, grounding, etc.) cannot account for their epistemic value. For "properties are cheap": in addition to natural properties and any value the realist might attach to them, there are also "shmatural" properties (standing to natural properties like charge and mass as Goodman's grue and bleen stand to green and blue) and a corresponding "shmvalue" of theorizing in terms of them. Dasgupta's challenge is one of objectivity: the existence of the "shmamiked" network of concepts threatens the objectivity of facts stated using the unshmamiked network. But the challenge can be repelled given a proper understanding of objectivity itself.

Metaphysics is sensitive to the conceptual tools we choose to articulate metaphysical problems. Those tools are a lens through which we view metaphysical problems; the same problems look different when we change the lens. There has recently been a shift to "postmodal" conceptual tools: concepts of ground, essence, and fundamentality. This shift transforms the debate over structuralism in the metaphysics of science and philosophy of mathematics. Structuralist theses say that patterns are "prior" to the nodes in the patterns. In modal terms this would mean that the nodes cannot vary independently of the pattern. But its postmodal meaning is unclear. Does it mean, e.g., that a fundamental account of reality somehow speaks only of patterns? What would that mean? Three structuralist positions are examined through a postmodal lens: nomic/causal/dispositional essentialism, structuralism about individuals (e.g., structural realism, e.g., ante rem mathematical structuralism), comparativism about quantities. The question of when theories are equivalent, and how that impacts the debate over structuralism, is also discussed.

Most facts of grounding involve nonfundamental concepts, and thus must themselves be grounded. But how? The leading approaches—due to Bennett, deRosset, and Dagupta—are subject to objections. The way forward is to deny a presupposition common to the leading approaches, that there must be some simple formula governing how grounding facts are grounded. Everyone agrees that facts about cities might be grounded in some complex way about which we know little; we should say the same about the facts of grounding themselves. The kinds of facts that might enter into the grounds of the facts of grounding are explored at length.

Personal identity is not always symmetric: even if I will not be a later person, the later person may have been me. What makes this possible is that the relations that are criterial of personal identity---such as memory and anticipation---are asymmetric and "count in favor of personal identity from one side only". Asymmetric personal identity can be accommodated by temporal counterpart theory but not by Lewisian overlapping aggregates of person stages. The question of uncertainty in cases of personal fission (and in Everettian quantum mechanics) is also discussed.

According to Ross Cameron's version of the moving spotlight theory of time, (1) Past and future entities exist; (2) the properties and relations they have are those they have now; but nevertheless (3) there are no fundamental past- or future-tensed facts; instead, tensed facts are made true by fundamental facts about the possession of temporal distributional properties and facts about how old things are. I argue that the account isn't sufficiently distinct from the B-theory to fit the usual A-theorist's tastes and arguments, since i) like the traditional spotlight it consists of a B-theoretic metaphysics with one small A-theoretic element tacked on, and since ii) in a sense it does not admit fundamental change. I also argue that the proposed grounding of tensed facts in tenseless facts does not work in certain cases.

Act Utilitarianisms divide into Total and Average versions. Total versions seem to imply Parfit’s “Repugnant Conclusion”. Average versions are proposed in part to avoid the Repugnant Conclusion, but these are subject to “Mere Addition” arguments as detailed by Hudson in “The Diminishing Marginal Value of Happy People”. Thus, various intermediate versions of utilitarianism, such as the one investigated by Hurka in “Value and Population Size”, take on interest. But Hudson argues that such compromise theories are subject to the mere addition arguments, and are therefore no improvement over Average Utilitarianism. I disagree: some such compromise solutions escape Hudson’s Mere Addition arguments.

Nonreductive materialism is the dominant position in the philosophy of mind. The global supervenience of the mental on the physical has been thought by some to capture the central idea of nonreductive materialism: that mental properties are ultimately dependent on, but irreducible to, physical properties. But Jaegwon Kim has argued that global psychophysical supervenience does not provide the materialist with the desired dependence of the mental on the physical, and in general that global supervenience is too weak to be an interesting dependence relation. We argue that these arguments are unsound. Along the way, we clarify the relationship between global and strong supervenience, and show clearly what sort of dependence global supervenience provides.

I defend counterpart theory against post-Kripkean objections. Trenton Merricks objects that no construction of ersatz counterparts is uniquely and intrinsically suitable; I reply that metaphysical constructions need not have these features. Sarah Moss refutes my solution (from "All the world's a stage") to the problem of timeless counting for temporal counterpart theory; I offer a new solution. Hazen, Fara, Williamson, and others have objected that counterpart theory generates an unacceptable logic for an actuality operator; I attempt to give a better semantics.

Eternalists say that non-present entities (for instance dinosaurs) exist; presentists say that they do not. But some sceptics deny that this debate is genuine, claiming that presentists simply represent eternalists' quantifiers over non-present entities in different notation. This scepticism may be refuted on purely logical grounds: one of the leading candidate ‘presentist quantifiers’ over non-present things has the inferential role of a quantifier. The dispute over whether non-present objects exist is as genuine and non-verbal as the dispute over whether there is life on other planets.

This note is to show that a well-known point about David Lewis’s (1986) modal realism applies to Timothy Williamson’s (1998; 2002) theory of necessary existents as well.1 Each theory, together with certain “recombination” principles, generates individuals too numerous to form a set. The simplest version of the argument comes from Daniel Nolan (1996).2 Assume the following recombination principle: for each cardinal number, ν, it’s possible that there exist ν nonsets. Then given Lewis’s modal realism it follows that there can be no set of all (that is, Absolutely All) the nonsets. For suppose for reductio that there were such a set, A; let ν be A’s cardinality; and let µ be any cardinal number larger than ν. By the recombination principle, it’s possible that there exist µ nonsets; by modal realism, there exists a possible world containing, as parts, µ nonsets; each of these nonsets is a member of A

While many are impressed with the utility of possible worlds in linguistics and philosophy, few can accept the modal realism of David Lewis, who regards possible worlds as sui generis entities of a kind with the concrete world we inhabit.1 Not all uses of possible worlds require exotic ontology. Consider, for instance, the use of Kripke models to establish formal results in modal logic. These models contain sets often regarded for heuristic reasons as sets of “possible worlds”. But the “worlds” in these sets can be anything at all; they can be numbers, or people, or sh. The set of worlds, together with the accessibility relation and the rest of the model, is used as a purely formal structure.2 One can even go beyond establishing results about formal systems and apply Kripke models to English, as Charles Chihara has recently argued.3 Chihara shows, for instance, how to use Kripke models (plus primitive modal notions) to give an account of validity for English modal sentences. In other cases worlds are not really needed at all. It is often vivid to give a counterexample thus: “There is a possible world in which P. Since your theory implies that in all worlds, not-P, your theory is wrong.” But the counterexample could just as easily be given using modal operators: “Possibly, P. Since your theory implies that it is necessary that not-P, your theory is wrong.”.

The intimate relationship between X and Y consists in the existence of (metaphysically) necessary truths correlating their occurrences/existences/instantiations. E would be in some sense “overdetermined” if caused by both X and Y.2 Some philosophers say this would be bad, that this cannot or does not happen, that we should construct theories ruling it out, at least in certain cases.3 But why? Given the necessary truths correlating objects and their parts, objects and events concerning those objects, physical and supervenient mental properties, and so on, X and Y do both seem to be causes of E. Should we say that a baseball..

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..

Locke’s view that continuants are numerically distinct from their constituting hunks of matter is popular enough to be called the “standard account”.1 It was given its definitive contemporary statement by David Wiggins in Sameness and Substance2, and has been defended by many since. Baker’s interesting book contributes new arguments for this view, a new definition of ‘constitution’, and a sustained application to persons and human animals. Much of what she says develops this view in new and important ways. But in some cases she does not advance the position, and in others she takes steps backwards. According to Baker, a person is numerically distinct from her constituting animal. One of Baker’s leading arguments is surprisingly unconvincing. Persons differ in important ways from non-human animals. Only persons are moral agents, modify their goals, have wars, culture, etc. If persons were identical to animals—if we were “nothing but animals”, as she puts it—then the manifest discontinuity between humans and non-human animals would be located “within the domain of biology”. “But from a biological point of view, human animals…are biologically continuous with non-human animals.” (p. 17) The argument fails: why should identifying persons with animals preclude saying that these particular animals have radically distinctive features that are of little interest to biologists? The traditional case for non-identity (which Baker accepts) is more powerful: a person and her constituting animal differ by having different persistence conditions. If my memories were transferred to a new body and my old body destroyed, I the person might survive, but the human animal who constituted me would perish. Therefore, before the transfer, I and the animal that constituted me would be numerically distinct but extremely similar things located in exactly the same place. This consequence—the central thesis of the Wiggins view—is surprising: so surprising that some reject the Wiggins view on that basis..