 Millians are not the only ones to have grappled with the implications that the Kripke-Donnellan attack on descriptivism has for the semantics of fictional names. Michael Devitt, for example, another early critic of descriptivism, has used the problem of fictional and other empty names to argue against Millianism and in favor of his version of a causal-historical theory of reference (cf. Devitt 1989). And Mark Sainsbury argues in Sainsbury 2005 that names, including fictional names, have singular but non-descriptive meanings that can be specified in a Davidson-style truth theory whose background logic is a Negative Free Logic (that is, a logic that counts simple or atomic sentences containing empty names as false). Given the role assigned to Negative Free Logic, it is scarcely surprising that the greatest challenge for such a framework is again the problem of external metafictional sentences such as  (4):