Abstract

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 ….