A possible world is a junky world if and only if each thing in it is a proper part. The possibility of junky worlds contradicts the principle of general fusion. Bohn (2009) argues for the possibility of junky worlds, Watson (2010) suggests that Bohn‘s arguments are flawed. This paper shows that the arguments of both authors leave much to be desired. First, relying on the classical results of Cantor, Zermelo, Fraenkel, and von Neumann, this paper proves the possibility of junky (...) worlds for certain weak set theories. Second, the paradox of Burali-Forti shows that according to the Zermelo-Fraenkel set theory ZF, junky worlds are possible. Finally, it is shown that set theories are not the only sources for designing plausible models of junky worlds: Topology (and possibly other "algebraic" mathematical theories) may be used to construct models of junky worlds. In sum, junkyness is a relatively widespread feature among possible worlds. (shrink)

The possibility of Junk is the possibility that something exists and everything is a proper part. Just as we might imagine that there are no simples—that everything has a proper part, all the way down—we might imagine that there are no caps—that everything is a proper part, all the way up. It is not obvious that this apparent possibility can be accommodated within a Lewisian modal framework. For Lewis, every possibility involves the existence of a possible world, and a possible (...) world is just is a maximal sum, and so a cap. But the Lewisian can accommodate Junk, if she wishes, by allowing parts of possible worlds to represent complete possibilities. (shrink)

An encyclopedia entry which covers various revisionary conceptions of which macroscopic objects there are, and the puzzles and arguments that motivate these conceptions: sorites arguments, the argument from vagueness, the puzzles of material constitution, arguments against indeterminate identity, arguments from arbitrariness, debunking arguments, the overdetermination argument, and the problem of the many.

Philosophers disagree whether composition as identity entails mereological universalism. Bricker :264–294, 2016) has recently considered an argument which concludes that composition as identity supports universalism. The key step in this argument is the thesis that any objects are identical to some object, which Bricker justifies with the principle of the universality of identity. I will spell out this principle in more detail and argue that it has an unexpected consequence. If the universality of identity holds, then composition as identity not (...) only leads us to universalism, but also leads to the view that there are no mereological atoms. (shrink)

Modal realism is an ontological position made familiar by David Lewis, according to which there exist possible worlds other than the actual world that we inhabit. It is hard to uphold modal realism, and indeed modal realism has only a few advocates. However, as most contemporary metaphysicians agree, this does not mean that it is easy to refute modal realism. In this paper, I argue against modal realism from a metaontological point of view. First, I provide a precise formulation of (...) modal realism based on Lewis’ discussion of modal realism. Second, I argue that modal realism is undermined unless it incorporates a view of metaontology known as ontological realism. Third, I point out that if modal realism incorporates ontological realism, it comes into conflict with its own formulation. (shrink)

When some objects are the parts of another object, they compose that object and that object is composite. This article is intended as an introduction to the central questions about composition and a highly selective overview of various answers to those questions. In §1, we review some formal features of parthood that are important for understanding the nature of composition. In §2, we consider some answers to the question: which pluralities of objects together compose something? As we will see, the (...) dominant answers are all of them and none of them. In §§3-4, we examine one of the main arguments that has driven philosophers to these extreme answers: the argument from vagueness. In §5, we turn to the question of whether composition is unique: is it sometimes the case that some things compose more than one thing? Finally, in §6, we turn from the question of which composites exist to the question of which composites exist fundamentally. (shrink)

(No abstract is available for this citation).

Thought: A Journal of Philosophy, EarlyView.

Analytic Philosophy, Volume 63, Issue 1, Page 44-61, March 2022.

Einar Bohn has argued that principles of composition must be contingent if gunky objects and junky worlds are both metaphysically possible. This paper critically examines such a case for contingentism about composition. I argue that weak mereological universalism, the principle that any two objects compose something, is consistent with the metaphysical possibility of both gunky objects and junky worlds. I further argue that, contra A. J. Cotnoir, the weak mereological universalist can accept a plausible mereological remainder axiom. The proponent of (...) contingent composition will have to look elsewhere for an argument in favor of his position. (shrink)

The paper presents different arguments against the necessity of mereological universalism. First, it argues that they are examples of a much more general argumentative structure. It then contends that some of these arguments cannot be resisted by distinguishing different variants of universalism that have been recently proposed in the literature—in contrast with recent suggestions to the contrary. Finally, it provides different ways to resist such contingentist arguments on behalf of universalists.

A mereological structure is junky if and only if each of its elements is a proper part of some other. The young literature on junk has focused on junky worlds and whether they are counterexamples to unrestricted composition. The present note defends the possibility of junky structures that are not worlds. This possibility complicates a recent attempt in the literature to render junk consistent with a weakened form of unrestricted composition. The upshot is that junky non-worlds threaten the weakened form (...) of unrestricted composition as much as junky worlds threaten the traditional version. (shrink)

All parts of mereologically ‘gunky’ entities have proper parts. All parts relevant to mereologically ‘junky’ entities *are* proper parts. This essay explores the application of gunk and junk beyond the standard category of material object. One such application yields what is here dubbed ‘deep’ gunk and junk: a material entity x all of whose intrinsic elements from any fundamental ontological category C either have proper parts from C that also are intrinsic elements of x, or are proper parts of entities (...) from C that also are intrinsic elements of x. In addition to being independently interesting, these mereological structures pose a challenge to the bare particular ontology of substance. For bare particulars standardly are assumed to be mereologically simple, yet a deep gunky or junky entity requires any associated bare particulars to be complex. The essay closes by examining the bare particular theorist’s prospects for answering this challenge. (shrink)

Those who accept the necessity of mereological universalism face what has come to be known as the ‘junk argument’ due to Bohn [2009], which proceeds from the incompatibility of junk with universalism and the possibility of junk, to conclude that mereological universalism isn't metaphysically necessary. Most attention has focused on ; however, recent authors have cast doubt on . This paper undertakes a defence of premise against three main objections. The first is a new objection to the effect that Bohn's (...) defence of that premise presupposes far too much. I show that one can defend premise from a much weaker set of assumptions. The second objection, due to Contessa [2012], is that those who accept unrestricted composition should only accept the existence of binary sums rather than infinitary fusions. I argue that this conception of unrestricted composition is problematic: it is in conflict with an intuitive remainder principle. The final objection is .. (shrink)

The paper presents different arguments against the necessity of mereological universalism. First, it argues that they are examples of a much more general argumentative structure. It then contends that some of these arguments cannot be resisted by distinguishing different variants of universalism that have been recently proposed in the literature—in contrast with recent suggestions to the contrary. Finally, it provides different ways to resist such contingentist arguments on behalf of universalists.