A dispute exists about whether bioethics should become a new discipline with its own methods, competency standards, duties, honored texts, and core curriculum. Unique expertise is a necessary condition for disciplines. Using the current literature, different views about the sort of expertise that might be unique to bioethicists are critically examined to determine if there is an expertise that might meet this requirement. Candidates include analyses of expertise based in "philosophical ethics," "casuistry," "atheoretical or situation ethics," "conventionalist relativism," "institutional guidance," (...) "regulatory guidance and compliance," "political advocacy," "functionalism," and "principlism." None succeed in identifying a unique area of expertise for successful bioethicists that could serve as a basis for making it a new discipline. Rather expertise in bioethics is rooted in many professions, disciplines and fields and best understood as a second-order discipline. (shrink)