© 2010, Peter Tan


A subject of much recent philosophical discussion is the thesis that for any finite class of objects, the xs, there is necessarily an object composed of those xs. Composition is unrestricted. Some support for this view arises from concerns about whether composition can be a vague matter. Ted Sider offers an ‘argument from vagueness’ in defense of unrestricted mereological composition which relies heavily on the premise that composition cannot be vague. However, he endorses a particular view of vagueness which, I propose, commits him to abandoning certain premises of his argument. I will defend Sider’s charge that composition cannot be vague. I will argue, though, that Sider should actually be committed to accepting sharp cutoffs with regard to composition, since the theory of vagueness Sider endorses itself requires sharp cutoffs. The purpose of this paper is to show that his views on vagueness and sharp cutoffs are at conflict with one another, and because of that, his argument for unrestricted composition fails.

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