Online research in philosophy

It is standardly assumed that there are three — and only three — ways to solve problem of temporary intrinsics: (a) embrace presentism, (b) relativize property possession to times, or (c) accept the doctrine of temporal parts. The first two solutions are favoured by endurantists, whereas the third is the perdurantist solution of choice. In this paper, I argue that there is a further type of solution available to endurantists, one that not only avoids the usual costs, but is structurally identical to the temporal-parts solution preferred by perdurantists. In addition to providing a general characterization of this new type of solution, I discuss certain of its anticipations in the literature on bundle theory, as well as provide a detailed development of it in terms of my own preferred metaphysics of ordinary objects — namely, a distinctive form of substratum theory tracing to Aristotle.

Ignoring the temporal dimension, an object such as a railway tunnel or a human body is a three-dimensional whole composed of three-dimensional parts. The four-dimensionalist holds that a physical object exhibiting identity across time—Descartes, for example—is a four-dimensional whole composed of 'briefer' four-dimensional objects, its temporal parts. Peter van Inwagen (1990) has argued that four-dimensionalism cannot be sustained, or at best can be sustained only by a counterpart theorist. We argue that different schemes of individuation of temporal parts are available, which undermines van Inwagen's argument.

Most people who believe in temporal parts believe that the referents of our ordinary referring terms, like Bill Clinton, or that table, are fusions of temporal parts from past, present and future times. Call these fusions worms, and the theory that the referents of ordinary referring terms (ordinary objects) the worm theory. Buying the metaphysical theory of temporal parts does not immediately imply that we must buy the worm theory. Theodore Sider (1996, 2000), for example, has suggested that these ordinary referring terms just pick out a single, instantaneous, temporal part. Sider’s theory, called the stage theory, solves some pressing philosophical problems, including the problem of temporary intrinsics. But the stage theory has several difficulties of its own, especially what I will call the problem of long-term intrinsics. I argue for a rival theory, the growing individuals theory. On this theory, the referents of our ordinary referring terms have past and present temporal parts, but not future temporal parts. This theory best accounts for our intuitions about which intrinsic properties ordinary objects have.

Those who believe that ordinary things have temporal as well as spatial parts must give an account of the truth conditions of temporally modified predications of the form ‘a is F at t ’ in terms of temporal parts. I will argue that the friend of temporal parts is committed to an account of temporal predication that is incompatible with the classical principle of predicate abstraction.

If ordinary objects have temporal parts, then temporal predications have the following truth conditions: necessarily, ( a is F) at t iff a has a temporal part that is located at t and that is F. If ordinary objects have temporal counterparts, then, necessarily, ( a is F) at t iff a has a temporal counterpart that is located at t and that is F. The temporal-parts account allows temporal predication to be closed under the parthood relation: since all that is required to be F at t is to have a temporal part, a t , that is located at t and that is F, every object that has a t as a temporal part is F at t . Similarly for the temporal-counterparts account. Both closure under parthood and closure under counterparthood are shown to have unacceptable consequences. Then strategies for avoiding closure are considered and rejected.

1 A particular may have other particulars as parts, but according to the bundle theory its ultimate constituents are confined to universals. Parts are different from constituents or components. A part is a type of constituent, but there are constituents that are not parts. Parts belong to the same general category as the whole: if a concrete particular has parts, those parts will themselves be concrete particulars. This is not always the case with constituents: the constituents of a fact do not have to be facts and the constituents (or members) of a set do not have to be sets. The relation of “being a part of” is also transitive, whereas the relation of “being a constituent of” is not always transitive. If a particular has parts, such as atoms, then its constituents include its intrinsic properties, its atoms, and the arrangement relation. If an atom has parts, such as subatomic particles, then the constituents of the atom include its properties, the subatomic particles, and the arrangement universal. If it is like this all the way down without any termination (no bedrock), then the bundle theory says that at each stage there are only universals and ordinary particulars with parts, in other words there are no bare particulars. This approach should also work if there were arbitrary undetached parts that are real entities. The alternative to no bedrock is metaphysical atomism. There are two ways that metaphysical atomism could be true in classical mechanics: (1) if the ultimate constituents of matter are point particles — perhaps electrons are point particles, (2) if matter is continuously divisible and arbitrary undetached parts are not real entities or real parts. But it would be rash to say that these were the only two options for all theories. Point particles are a convenient kind of particular to think about when discussing the bundle theory. There could be just three properties bundled together, a certain mass, a certain charge, and the property of being point like..

Adopting temporal parts theory is the most popular way of addressing a host of puzzles about diachronic identity. For example, it is not obvious how I am the same person as the baby who shared my name. With the theory, sameness of person, e.g., consists in being comprised by the same temporally extended, four-dimensional object. However, temporal parts theory has unacceptable consequences for notions of freedom and probability. I show that the only acceptable reading of four-dimensionalism entails that the four dimensional object that is me, say, already exists in its entirety. This entails that all of my future properties are already set. This nearly Spinozistic result robs us of familiar notions of choice and possibility. I argue that these notions are more central to our thinking than temporal parts theory, and that on these grounds we must look elsewhere for solutions to our questions about identity across time.

One often hears a complaint about “bare particulars”. This complaint has bugged me for years. I know it bugs others too, but no one seems to have vented in print, so that is what I propose to do. (I hope also to say a few constructive things along the way.) The complaint is aimed at the substratum theory, which says that particulars are, in a certain sense, separate from their universals. If universals and particulars are separate, connected to each other only by a relation of instantiation, then, it is said, the nature of these particulars becomes mysterious. In themselves, they do not have any properties at all. They are nothing but a pincushion into which universals may be poked. They are Locke’s “I know not what” (1689, II, xxiii, §2); they are Plato’s receptacles (Timaeus 48c–53c); they are “bare particulars”.1 Against substratum theory there is the bundle theory, according to which particulars are just bundles of universals. The substratum and bundle theories agree on much. They agree that both universals and particulars exist. And they agree that a particular in some sense has universals. (I use phrases like ‘particular P has universal U ’ and ‘particular P ’s universals’ neutrally as between the substratum and bundle theories.) But the bundle theory says that a particular is exhaustively composed of (i.e., is a mereological fusion of) its universals. The substratum theory, on the other hand, denies this. Take a particular, and mereologically subtract away its universals. Is anything left? According to the bundle theory, no. But according to the substratum theory, something is indeed left. Call this remaining something a thin particular. The thin particular does not contain the universals as parts; it instantiates them.

This paper is an articulation and defense of a trope-bundle theory of material objects. After some background remarks about objects and tropes, I start the main defense in Section III by answering a charge frequently made against the bundle theory, namely that it commits a conceptual error by saying that properties are parts of objects. I argue that there’s a general and intuitive sense of “part” in which properties are in fact parts of objects. This leads to the question of qualitative unity: in virtue of what are certain properties unified as parts of an object? In Section IV I defend an account of unity for complex material objects. It turns on the thesis that the properties of such objects are structural properties. After addressing some objections, I turn in Section V to the question of unity for simple material objects. Here a different and more radical account is needed, for simples, since they do not have structural properties, are not subsumed by the account of Section IV. I defend the view that a simple object just is a simple property, so that identity delivers the desired unity.

Bundle theory takes objects to be bundles of properties. Some bundle theorists take objects to be bundles of instantiated universals, and some take objects to be bundles of tropes. Tropes are instances of properties: some take instantiated universals to be tropes, while others deny the existence of universals and take tropes to be ontologically fundamental. Historically, the bundling relation has been taken to be a primitive relation, not analyzable in terms of or ontologically reducible to some other relation, and has been variously characterized as, e.g., “compresence,” “concurrence,” or “consubstantiation.” Bertrand Russell (1940) defends compresence of universals, and Hector-Neri Castañeda (1974) defends consubstantiation of universals. John Bacon (1995) defends concurrent tropes and Keith Campbell (1990) defends compresent tropes. Jonathan Schaffer (2001) bucks this trend, endorsing compresence understood as co-location in spacetime, but this brings with it undesireable consequences such as the impossibility of distinguishing between objects (such as electrons or other microentities) with the same location. Mereological bundle theory improves upon traditional bundle theory by taking the primitive relation of bundling to be the more familiar relation of fusing or composing, such that objects are fusions of properties or fusions of property instances. Hence, mereological bundle theorists endorse a property mereology: a mereology where properties or property instances can be parts of objects. An advantage of the approach derives from the fact that standard mereologies take composition to be primitive or define it using a different primitive mereological notion (such as primitive parthood). Thus, taking the basic primitive of bundle theory to be composition can reduce the need for..