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.

An overview of contemporary part-whole theories, with reference to both their axiomatic developments and their philosophical underpinnings.

Realists wanting to capture the facts of quantum entanglement in a metaphysical interpretation find themselves faced with several options: to grant some species of fundamental nonseparability, adopt holism, or to view localized spacetime systems as ultimately reducible to a higher-dimensional entity, the quantum state or wave function. Those adopting the latter approach and hoping to view the macroscopic world as grounded in the quantum wave function face the macro-object problem. The challenge is to articulate the metaphysical relation obtaining between three-dimensional (...) macro-objects and the wave function so that the latter may be seen in some sense as constituting the former. This paper distinguishes several strategies for doing so and defends one based on a notion of partial instantiation. (shrink)

A famous mathematical theorem says that the sum of an infinite series of numbers can depend on the order in which those numbers occur. Suppose we interpret the numbers in such a series as representing instances of some physical quantity, such as the weights of a collection of items. The mathematics seems to lead to the result that the weight of a collection of items can depend on the order in which those items are weighed. But that is very hard (...) to believe. A puzzle then arises: How do we interpret the metaphysical significance of this mathematical theorem? I first argue that prior solutions to the puzzle lead to implausible consequences. Then I develop my own solution, where the basic idea is that the weight of a collection of items is equal to the limit of the weights of its finite subcollections contained within ever-expanding regions of space. I show how my solution is intuitively plausible and philosophically motivated, how it reveals an underexplored line of metaphysical inquiry about quantities and locations, and how it elucidates some classic puzzles concerning supertasks. (shrink)

In this thesis I argue against unrestricted mereological hybridism, the view that there are absolutely no constraints on wholes having parts from many different logical or ontological categories, an exemplar of which I take to be ‘mixed fusions’. These are composite entities which have parts from at least two different categories – the membered (as in classes) and the non-membered (as in individuals). As a result, mixed fusions can also be understood to represent a variety of cross-category summation such as (...) the abstract with the concrete, the physical with the non-physical, and the possible with the impossible, just to name a few. -/- Proposed by David Lewis (1991) alongside his defence of classical mereology (the major theory of parthood which permits such transcategorial composites through its principle of unrestricted composition) it is my contention that mixed fusions are an under-examined consequence of indiscriminate mereological fusion which harbour a multitude of complications. In my attempt to discern their substantive character, throughout this thesis I make a case study of mixed fusions and uncover several problematic consequences which I think follow from their most plausible assessment. -/- These include: (1) that mixed fusions’ probable membership relations may lead to dubious foundational loops in the mereological Universe, or (2) otherwise that mixed fusions oblige an implausible ontological priority of the mereological Universe as a whole; (3) that mixed fusions contradict the reductive account of set theory they are proposed within, by plausibly being seen to have the same members as their class parts, and (4) that mixed fusions therefore confound a mereological thesis of Composition as Identity, which some (including Lewis) use to support classical mereology – a consequence which is potentially self-defeating; (5) that mixed fusions as sums of abstract and concrete entities both subvert Lewis’s (1986) system of modal realism, while (6) also undermining less expansive theories of possible worlds; and finally, (7) that even where some of the foregoing is resisted, it remains implausible that mixed fusions are ontologically innocent, because their supposed distinction from their parts in this case ensures that they need to be counted as additional entities in one’s ontology. -/- To be clear, I do not advance a theory of mereological hybrid nihilism in the sense of denying all cases of transcategorial composition. (I only cover a few select instances of mereological hybridism via mixed fusions after all.) Rather, I deny that mereological hybridism is plausible in full generality, by demonstrating that any cases of it are at least limited by the constraints that I identify. This in turn vindicates a call for a restriction on parthood theories and composition principles which allow certain types of categorially mixed entities – including restricting classical mereology with its principle of unrestricted composition. -/- Although theories of parthood like the standard classical mereology are not ordinarily developed for the sake of mereological hybrids like mixed fusions, these and other transcategorial composites are still among the logical consequences of such parthood systems operating with sufficient generality. The significance of my thesis, then, comes from showcasing how some of these kinds of entities do not conform to the systems in which they are included as required, and hence I argue for the rejection of unrestricted mereological hybridism as well as any mereological principles which support it. (shrink)

The recent literature on the nature of persistence features a handful of imaginative cases in which an object seems to colocate with itself. So far, discussion of these cases has focused primarily on how they defy the standard endurantist approaches to the problem of temporary intrinsics. But in this article, I set that issue aside and argue that cases of apparent self-colocation also pose another problem for the endurantist. While the perdurantist seems to have a fairly straightforward account of self-colocation, (...) the endurantist has a hard time saying exactly what it would be for an object to be self-colocated. After introducing this problem and explaining how the perdurantist can circumvent it with little difficulty, I discuss a number of tempting endurantist solutions that ultimately fail. Then I suggest an endurantist solution which I think is more promising, but which requires the endurantist to deny that apparent cases of self-colocation are genuine cases of self-colocation. (shrink)

The paper discusses the concept of the cognitive niche and distinguishes the latter from the metabolic niche. By using these posits I unpack certain ideas that are crucial for the enactivist movement, especially for its original formulation proposed by Varela, Thompson and Rosh. Drawing on the ontology of location, boundaries, and parthood, I argue that enacting the world can be seen as the process of cognitive niche construction. Moreover, it turns out that enactivism—as seen through the lens of the conceptual (...) framework proposed in the paper—considers cognition as a kind of connection between the subject and the world. This post is pointed to as the key idea laid down in enactivism. (shrink)

Material objects extend through space by having different spatial parts in different places. But how do they persist through time? According to some philosophers, things have temporal parts as well as spatial parts: accepting this is supposed to help us solve a whole bunch of metaphysical problems, and keep our philosophy in line with modern physics. Other philosophers disagree, arguing that neither metaphysics nor physics give us good reason to believe in temporal parts.

Current formulations of Four-Dimensionalism may be objected to on grounds that they are too inflexible: the formulations do not seem to allow for enough variety in the views they are paired with. For instance, Kit Fine has noted that formulations of Four-Dimensionalism in terms of instantaneous parts may be too demanding for Four-Dimensionalists who believe nothing is instantaneous. And Trenton Merricks has argued that one can think something persists four-dimensionionally without taking it to have proper temporal parts, and claims that (...) our formulation of Four-Dimensionalism should be revised to allow for this. I will add my own worries to those of Fine and Merricks. I will note that current formulations of Four-Dimensionalism are not sufficiently neutral with respect to the structure of time, with respect to how liberally objects decompose into parts, and with respect to whether objects and the regions they fill match in mereological structure. I will show that we can formulate Four-Dimensionalism in a sufficiently neutral way, while still producing a view that can do the work we typically require of Four-Dimensionalism. (shrink)

Some philosophers have claimed that kinds can be construed as mereologically complex structural properties. This essay examines several strategies aimed at construing a certain class of natural kinds, namely isomeric chemical kinds, in accordance with this view. In particular, the essay examines views which posit structural proper parts in addition to micro-constitutive parts to individuate isomeric chemical kinds. It then goes on to argue that the phenomenon of chirality in stereochemistry gives the proponent of kinds-as-complex-properties evidence for positing the existence (...) of causal-cum-dispositional individuating proper parts, in addition to structural parts, for chemical enantiomeric kinds. (shrink)

In both the historical and contemporary literature on the metaphysics of space, a core dispute is that between relationism and substantivalism. One version of the latter is supersubstantivalism, according to which space is the only kind of substance, such that what we think of as individual material objects are actually just parts of spacetime which instantiate certain properties. If those parts are ontologically dependent on spacetime as a whole, then we arrive at an ontology with only a single genuinely independent (...) substance, namely the entire spacetime manifold. This is monist supersubstantivalism. A view on which the parts of spacetime are ontologically prior to the whole has been called pluralistic supersubstantivalism. As currently formulated, supersubstantivalism carries significant advantages and encounters major difficulties. I argue that some of the latter motivate... (shrink)