Mereological vagueness and existential vagueness

It is often assumed that indeterminacy in mereological relations-in particular, indeterminacy in which collections of objects have fusions-leads immediately to indeterminacy in what objects there are in the world. This assumption is generally taken as a reason for rejecting mereological vagueness. The purpose of this paper is to examine the link between mereological vagueness and existential vagueness. I hope to show that the connection between the two forms of vagueness is not nearly so clear-cut as has been supposed.