Patients and physicians can inhabit distinctive social worlds where they are guided by diverse understandings of moral practice. Despite the contemporary presence of multiple moral traditions, religious communities and ethnic backgrounds, two of the major methodological approaches in bioethics, casuistry and principlism, rely upon the notion of a common morality. However, the heterogeneity of ethnic, moral, and religious traditions raises questions concerning the singularity of common sense. Indeed, it might be more appropriate to consider plural traditions of moral reasoning. This poses a considerable challenge for bioethicists because the existence of plural moral traditions can lead to difficulties regarding "closure" in moral reasoning. The topics of truth-telling, informed consent, euthanasia, and brain death and organ transplantation reveal the presence of different understandings of common sense. With regard to these subjects, plural accounts of "common sense" moral reasoning exist.