This paper argues that the core principle of bioethics, autonomy, is rooted both in the 20th century history of the development of new medical technologies as in political liberalism transferred to medical practices, rendering the medical decision-making of patients a centerpiece of medical interventions. The paper shows how the ambiguity in the interpretation of autonomy reflects the ambivalence of bioethics towards making normative claims on the moral agents insofar as these go beyond the respect for a patient’s autonomy. In the second part, the paper analyzes the alternative approach of care ethics, which intends to emphasize both the vulnerability and dependency of the patient and the medical professions’ responsibility to care for the patient. However, neither ‘autonomy’ nor ‘care’ ethics approaches can address the social and institutional mediations of today’s health care ethics; the paper therefore concludes with a proposal to embrace a critical social-ethical approach to bioethics that is based on the tradition of human rights.