Philosophy textbooks typically treat bioethics as a form of "applied ethics"—i.e., an attempt to apply a moral theory, like utilitarianism, to controversial ethical issues in biology and medicine. Historians, however, can find virtually no cases in which applied philosophical moral theory influenced ethical practice in biology or medicine. In light of the absence of historical evidence, the authors of this paper advance an alternative model of the historical relationship between philosophical ethics and medical ethics, the appropriation model. They offer two historical case studies to illustrate the ways in which physicians have "appropriated" concepts and theory fragments from philosophers, and demonstrate how appropriated moral philosophy profoundly influenced the way medical morality was conceived and practiced.