According to standard, pre-philosophical intuitions, there are many composite objects in the physical universe. There is, for example, my bicycle, which is composed of various parts - wheels, handlebars, molecules, atoms, etc. Recently, a growing body of philosophical literature has concerned itself with questions about the nature of composition.1 The main question that has been raised about composition is, roughly, this: Under what circumstances do some things compose, or add up to, or form, a single object? It turns out that (...) it is surprisingly difficult to give a satisfactory answer to this question that accords with standard, pre-philosophical intuitions about the universe's composite objects. In fact, the three rival views in response to this question that have received the most support in the literature are (i) that there are no objects composed of two or more parts (which means that there are no stars, chairs, humans, or bicycles);2 (ii) that the only objects composed of two or more parts are living organisms (which still means no stars. (shrink)

The paper comprises an attempt on the part of the author to understand what hylomorphism is, both in its original Aristotelian guise, and in recent work by philosophers who defend what they call hylomorphism. Two species or strands of hylomorphism are identified and discussed. Universals, essences, and substantial and accidental forms make cameo appearances, and the implications of an Aristotelian ontology of stuffs are explored.

Leibniz famously argues that there must be simple substances, since there are composites, and a composite is nothing but a collection of simples. I reconstruct Leibniz’s argument, showing that it relies on a commitment to mereological nihilism (i.e., the view that composites cannot be true beings). I show further that Leibniz endorses mereological nihilism as early as the 1680s and offers both direct and indirect support for this commitment: indirect support via the notion of unity and direct support via the (...) notion of persistence. I then assess the alignment of Leibniz’s mereological nihilism with his other commitments during the 1680s, including his potential commitment to corporeal substances. I argue that any viable interpretation of Leibniz’s commitment to corporeal substances is compatible with mereological nihilism, which provides a new perspective both on Leibniz’s developing theory of substance and on his mature theory of simple substance. (shrink)

Mereological nihilism is the philosophical position that there are no items that have parts. If there are no items with parts then the only items that exist are partless fundamental particles, such as the true atoms (also called philosophical atoms) theorized to exist by some ancient philosophers, some contemporary physicists, and some contemporary philosophers. With several novel arguments I show that mereological nihilism is the correct theory of reality. I will also discuss strong similarities that mereological nihilism has with empirical (...) results in quantum physics. And I will discuss how mereological nihilism vindicates a few other theories, such as a very specific theory of philosophical atomism, which I will call quantum abstract atomism. I will show that mereological nihilism also is an interpretation of quantum mechanics that avoids the problems of other interpretations, such as the widely known, metaphysically generated, quantum paradoxes of quantum physics, which ironically are typically accepted as facts about reality. I will also show why it is very surprising that mereological nihilism is not a widely held theory, and not the premier theory in philosophy. (shrink)

Radically permissive ontologies like mereological universalism and material plenitude are typically motivated by concerns about arbitrariness or anthropocentrism: it would be objectionably arbitrary, the thought goes, to countenance only those objects that we ordinarily take there to be. Despite the prevalence of this idea, it isn't at all clear what it is for a theory to be “objectionably arbitrary,” or what follows from a commitment to avoiding arbitrariness in metaphysics. This paper aims to clarify both questions, and examines whether arguments (...) from arbitrariness really are the proper foundations for one or both varieties of ontological permissivism. I argue that these considerations (even when made more precise) are far less successful at motivating radical forms of permissivism than we often take them to be. To do better, permissivists must either supply a much more developed metaphysics of material objects, or a controversial (but tempting) conception of what we're doing when we do metaphysics. (shrink)

In defending the startling claim that that there are no artifacts, indeed, no inanimate material objects of the familiar sort, Peter van Inwagen has argued that truths about such putative objects can be paraphrased as truths that do not make essential reference to them and that we should endorse only the ontological commitments of the paraphrase. In this note I argue that the paraphrases van Inwagen recommends cannot meet his condition. Read one way, they lose us some truths. Read another, (...) they entail the existence of the very objects they are supposed to rid us of. However, we need not share van Inwagen's distaste for the latter: to say that they exist is not to say that anything exists in addition to the simples composing them. (shrink)