Cornell University Ithaca, NY 14850 [email protected] are motorcycles made of? Presumably the answer is something like ‘wheels, pistons, fuel lines …’ or perhaps ‘metal, leather, plastic …’. Whatever precisely the parts of a motorcycle are, surely they are all material. Kathrin Koslicki disagrees. She has recently argued that ordinary material objects like motorcycles not only have material proper parts, but also have formal proper parts . On her view, an accurate list of the proper parts of a motorcycle must include (...) something like motorcyclehood in addition to the sorts of things just listed. Although she remains neutral about what exactly such a formal part is , she is explicit about what it does. The formal part of an object dictates structure; it dictates how the material parts must be arranged. It is ‘a kind of recipe for how to build wholes of that particular kind’ . Koslicki claims that this recipe or structure is itself a proper part of every motorcycle. That is what she calls the Neo-Aristotelian Thesis . A strange claim! So let us examine Koslicki’s argument for it. She begins by asking us to consider a case in which an artist shapes a single lump of clay L, thereby creating a statue S. The argument then proceeds as follows : The argument for the Neo-Aristotelian Thesis:1.It is possible to make an object S from a single preexisting material ingredient L. 2.L is a proper part of S. 3.Weak Supplementation: anything that has a proper part has at least two non-overlapping proper parts. 4.S has a proper part Q that does not overlap L . 5.S has no material proper parts other than L 6.Q is a proper part, but not a material proper part, of S 7.S has …. (shrink)

This paper is a systematic exploration of non-wellfounded mereology. Motivations and applications suggested in the literature are considered. Some are exotic like Borges’ Aleph, and the Trinity; other examples are less so, like time traveling bricks, and even Geach’s Tibbles the Cat. The authors point out that the transitivity of non-wellfounded parthood is inconsistent with extensionality. A non-wellfounded mereology is developed with careful consideration paid to rival notions of supplementation and fusion. Two equivalent axiomatizations are given, and are compared to (...) classical mereology. We provide a class of models with respect to which the non-wellfounded mereology is sound and complete. (shrink)

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

I argue that it is intuitive and useful to think about composition in the light of the familiar functionalist distinction between role and occupant. This involves factoring the standard notion of parthood into two related notions: being a parthood slot and occupying a parthood slot. One thing is part of another just in case it fills one of that thing's parthood slots. This move opens room to rethink mereology in various ways, and, in particular, to see the mereological structure of (...) a composite as potentially outreaching the individual entities that are its parts. I sketch one formal system that allows things to have individual entities as parts multiple times over. This is particularly useful to David Armstrong, given Lewis's charge that his structural universals must do exactly that. I close by reflecting upon the nature and point of formal mereology. (shrink)

Brentano uses terms in place of predicates (e.g. "a thinker" in place of "thinks") and characterizes the "is" of predication in terms of the part-whole relation. Taking as his ontological data certain intentional phenomena that are apprehended with certainty, he conceives the substance-accident relation as a defmeable type of part-whole relation which we can apprehend in "inner perception". He is then able to distinguish the following types of individual or ens reale: substances; primary individuals which are not substances; accidents; aggregates; (...) and boundaries. (shrink)

Aristotelian substance theory tells us that substances have structures (read: forms) as proper parts. This claim has recently been defended by Kathrin Koslicki who dubbed it the ‘Neo-Aristotelian Thesis.’ Strangely, Aristotelianism has not yet been universally embraced by philosophers – partly because some of its claims, such as the Neo-Aristotelian Thesis – are viewed by some as counterintuitive at best. In this paper, I argue for Aristotelianism by showing its philosophical usefulness: specifically, I put it to use in saving the (...) metaphysical doctrine of endurantism and some central mereological doctrines (such as Transitivity) from recent attacks. This utility gives us reason to endorse Aristotelianism. Along the way, I defend Koslicki's argument for the Neo-Aristotelian Thesis from a recent criticism, thus helping provide still more reason to endorse Aristotelianism: namely, Koslicki's vindicated argument. (shrink)