 The ersatzist may respond by biting the bullet. Even without admitting impossible worlds, most possible worlds accounts do not aim at providing a reductive and complete analysis of modality. (Lewis’s modal realism does. But it may not succeed, when so-called ‘alien’ properties, not instantiated by anything at the actual world nor obtainable as constructions out of actually instantiated properties, enter the stage. See Divers 2002, Chapter 7; Divers &amp; Melia 2002.) 