Discussion of moral explanation has reached an impasse, with proponents of contemporary ethical naturalism upholding the explanatory integrity of moral facts and properties, and opponents--including both antirealists and non-naturalistic realists--insisting that such robustly explanatory pretensions as moral theory has be explained away. I propose that the key to solving the problem lies in the question whether instances of moral properties are causally efficacious. It is argued that, given the truth of contemporary ethical naturalism, moral properties are causally efficacious if the (...) properties of the special sciences are. (shrink)