 It isn’t clear just who is a magical ersatzist. Lewis wrote that at the time he wrote Plurality no one explicitly endorsed this theory. This was perhaps unfair to various primitivists about modality, such as Adams (1974), Plantinga (1974) and Stalnaker (1976). Given the negative definition of magical ersatzism, and given the fact that primitivists do not think that possible worlds represent possibilities via any familiar mechanism, it seems the primitivists should count as magical ersatzists, or, as Lewis calls them, “magicians”. In any case, if magical ersatzism, in all its varieties, is objectionably mysterious, that suggests ersatzism is in trouble, and hence if we want the benefits of possible worlds, we have to pay for them by accepting concrete possible worlds.