Abstract

In “Extensionality of Parthood and Composition,”1 Achille Varzi mounts a spirited defense of the extensionality of parthood, or ‘EP’. According to EP, if x and y are composite objects with all the same proper parts then x = y.2 A number of philosophers, he notes, have objected that EP is false on the grounds that, for example, a statue and lump of clay (or a tinkertoy house and the wood from which it is made, in Varzi’s example) are distinct yet share all their proper parts. A number of considerations — for example, that a statue and lump of clay have different persistence conditions — are commonly raised to support this non-extensionalist conclusion. Varzi maintains, on the other hand, that this case and others like it do not support non-extensionalism. However, there are reasons to doubt the cogency of his argument. In outline, Varzi’s argument runs as follows. Suppose that (i) α and β are (say) a statue and a lump, respectively,3 and also suppose that (ii) α = β. ∗This is a draft and so unsuitable for citation in any form. Any comments or suggestions are welcome and can be emailed to me at [email protected]. Check back periodically for newer versions. 1Varzi 2008 2Varzi 2008, p. 108. 3To avoid complications, let’s assume throughout that they have the same lifespan. Naturally, we should suppose they are co-located