In his excellent 2001 book, Four-Dimensionalism: An Ontology of Persistence and Time, Theodore Sider defends a four-dimensionalist approach to persistence. I argue that, despite all of its many significant virtues, Sider’s case for four-dimensionalism is troubling in certain crucial respects, both philosophically and meta-philosophically. I show that, when we evaluate Sider’s evidence in favor of the stage-theory, a different assessment of the dialectical situation from that endorsed by Sider recommends itself. In the end, as I argue, everything turns on "the argument from vagueness" (Sider, 2001, ch. 4), arguably the most important and innovative argument Sider offers in support of four-dimensionalism. The argument from vagueness, however, suffers from an arguably fatal flaw and hence cannot bear the heavy dialectical burden of resolving the relative stand-off between the three-dimensionalist and the four-dimensionalist. Thus, due to the problematic nature of the argument from vagueness, Sider’s case in favor of four-dimensionalism is in the end not successful. Given the philosophically and meta-philosophically troubling consequences of the argument from vagueness, we are in any case much better off with a different ontology and a different conception of what it means to do metaphysics from that endorsed by Sider.