American law, not philosophy or medicine, is the major force shaping American bioethics. This is both because law at its best fosters individual rights, equality, and justice, and because violation of the legal duty or "standard of care" a physician owes a patient can lead to a malpractice suit. The law has therefore had two conflicting impacts on medical ethics: the positive effect of eroding paternalism and replacing it with a patient-centered ethic; and the negative effect of encouraging physicians to be more concerned with avoiding litigation than doing the "right" thing. Standard of Care explores the fundamental value conflicts confronting medicine and society by examining courtroom resolutions of real bioethical disputes, often of constitutional dimension. This case-based approach, which ranges from abortion to euthanasia, from AIDS to organ transplantation, from genetic research to the artificial heart and rationing, illuminates the value choices with which the power (and impotence) of medicine confronts us. George Annas urges health care professionals to go beyond the minimalist legal "standard of care" by promoting a vigorous, patient-centered medical ethics based on respect for human rights and responsibility to both patients and society. If modern medicine is to enhance human life, a reconceptualization of law as the beginning of ethical discourse, rather than as an instrument to end it, is essential. Such a discourse could enrich all our lives by helping us to articulate both a national and international agenda for human rights in health.