In this article (1) I extract from Brentano’s works (three) formal arguments against “genealogical explanations” of ethical claims. Such explanation can also be designated as “naturalism” (not his appellation); (2) I counter these arguments, by showing how genealogical explanations of even apodictic moral claims are logically possible (albeit only if certain unlikely, stringent conditions are met); (3) I show how Nietzsche’s ethics meets these stringent conditions, but evolutionary ethics does not. My more general thesis is that naturalism and intuitionism in (...) ethics need not be mutually incompatible. (shrink)