Daniel Steel’s new book on the precautionary principle illustrates the need to work ahead to fuse perspectives of epistemology and philosophy of science with those of ethics to accomplish progress in the debate on the proper role of precaution in a broad selection of bioethical areas. Steel advances the territory greatly with regard to conceptual clarity and epistemology, but from a bioethics standpoint he is mistaken in discounting the need for ethical underpinnings of a sound theory of the precautionary principle.