 Quinn argues that an adequate explanation need not require a complete explanation (2005: 584–85); a partial explanation might do just as well, depending on the context. Among these adequate explanations of why this actual world obtains rather than another possible world (including one with no contingent beings) is that the universe is an inexplicable brute fact or that God strongly actualized the world (although not everything in it). He refuses to take sides on the debate between explanations, except to say that science cannot provide an adequate explanation if the explanatory chain is infinite, for the chain of causes is itself contingent or it ends in an initial contingency not scientifically accountable. However, not only does Quinn not clarify what constitutes an adequate explanation, but as Pruss contends, the PSR “is not compatible with an infinite chain of explanations that has no ultimate explanans” (2006: 17), for in an infinite chain something puzzling remains to be explained, with the result that the PSR would again be invoked to explain what is puzzling. However, as we will question below, is the brute fact of the universe any more unacceptable as a complete explanation than the brute fact of a necessary being (God)?