The problem of the many threatens to show that, in general, there are far more ordinary objects than you might have thought. I present and motivate a solution to this problem using many-one identity. According to this solution, the many things that seem to have what it takes to be, say, a cat, are collectively identical to that single cat.

Mainstream metaphysics has been preoccupied by inquiring into the nature of major kinds of entities, like objects, properties and events, while avoiding minor entities, like shadows or holes. However, one might want to hope that dealing with such minor entities could be profitable for even solving puzzles about major entities. I propose a new ontological puzzle, the Shadow of Constitution Puzzle, incorporating the old puzzle of material constitution, with shadows in the role of the minor entity to guide our approach (...) to the issues involved. I then analyze the standard answers to the original puzzle of constitution, in their role as potential solutions to the new puzzle. Finally, I discuss three views that can solve the proposed puzzle. (shrink)

As I will use the term, an object is a mereological sum of some things just in case those things compose it simply in virtue of existing. In the first half of this paper, I argue that there are no sums. The key premise for this conclusion relies on a constraint on what, in certain cases, it takes for something to ground, or metaphysically explain, something else. In the second half, I argue that in light of my argument against sums, (...) Universalism, which is perhaps the most widely accepted answer to the Special Composition Question, is false. (shrink)

In his “Farewell to Substance: A Differentiated Leave-Taking”, Peter Simons reaches the provocative conclusion that the concept of substance, as it is employed by metaphysicians, has become obsolete, since in the end there may be nothing at all which answers to it. No harm is done, Simons allows, if we continue to retain an everyday notion of substance, as long as we are aware of the limitations of this practice: there is no reason in general to expect that what is (...) salient from our specifically human point of view will retain a special place in light of our most considered scientific and metaphysical theories of the world. In this paper, I argue that, contrary to Simons’ pessimistic outlook, the concept of substance continues to retain its importance for metaphysics. Among the primary explanatory roles played by the concept of substance in metaphysics is its use in designating certain kinds of entities as occupying a privileged position relative to a particular ontology. But disputes over substancehood can also target the criteria themselves relative to which an ontologically privileged position is awarded to certain taxonomic categories. In these uses, we see the concept of substance employed in an absolute, a relational and a comparative sense, to designate items as substances simpliciter, as the substances of something else, or as more or less deserving of substance status. (shrink)

This paper explains the metaphysical implications of the view that species are individuals (SAI). I first clarify SAI in light of the separate distinctions between individuals and classes, particulars and universals, and abstract and concrete things. I then show why the standard arguments given in defense of SAI are not compelling. Nonetheless, the ontological status of species is linked to the traditional "species problem," in that certain species concepts do entail that species are individuals. I develop the idea that species (...) names are rigid designators and show how this provides additional motivation for SAI. (shrink)

This paper presents and defends an account of the coincidence of biological organisms with mereological sums of their material components. That is, an organism and the sum of its material components are distinct material objects existing in the same place at the same time. Instead of relying on historical or modal differences to show how such coincident entities are distinct, this paper argues that there is a class of physiological properties of biological organisms that their coincident mereological sums do not (...) have. The account answers some of the most pressing objections to coincidence, for example the so-called grounding problem , that material coincidence seems to require that coinciding objects have modal differences that do not supervene on any other properties. (shrink)

In this paper, I defend an indexical analysis of the abstract-concrete distinction within the framework of modal realism. This analysis holds the abstract-concrete distinction to be conceptually inseparable from the distinction between the actual and the merely possible, which is assumed to be indexical in nature. The resulting view contributes to the case for modal realism by demonstrating how its distinctive resources provide a reductive analysis of the abstract-concrete distinction. This indexical analysis also provides a solution to a sceptical problem (...) regarding our concreteness, which parallels the sceptical problem that motivates indexicalism about actuality. (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)

I reply to Hawthorne and Uzquiano’s arguments for the incompatibility between mereological universalism and plenitudinous co-location. I argue that a mereology in which antisymmetry for parthood fails is independently motivated, and allows for both universalism and plenitudinous co-location. There can be as many angels in a place as there are cardinalities.

An old paper of mine (in Finnish) on the "similarity" of quantity tropes. See "Quantity Tropes and Internal Relations", "Kinds of Tropes without Kinds" and "The Ontological Form of Tropes" for more updated version of our theory.

This article defends strong formal ontological conception of ontological categories against Lewis's "deflanationary" conception. Here, it sides with E.J. Lowe (1998) among others. However, the paper argues against Lowe's conception of metaphysics as an a priori science. Different category systems are compared and the best system is selected on the basis of its ability to accommodate our the best a posteriori conceptions of reality.