A fundamental feature of modern medicine, both for professionals and for the public they serve, is its often life-and-death impact for patients. It is no accident or mere chance that decisions about life-sustaining treatment and care of the dying have been at the center both of the growth of biomedical ethics over the last two decades and of the virtually insatiable public fascination with modern medicine. But the dramatic new powers over life and death that are the great successes of modern medicine have generated widespread concern about how these powers are employed.

During these same last two decades the ideals and norms for physician/patient relations, and to a lesser extent the actual relations between physicians and patients, have been fundamentally transformed. From a largely paternalistic tradition in which treatment decision-making authority was in the hands of physicians and the patients' role was principally to comply with “doctors' orders,” a new, more egalitarian ideal of shared decision making between physicians and patients has emerged. From the traditional assumption that a, or even the, central aim of medicine was the preservation of life, a new recognition on the part of physicians and patients exists that medicine's new capacities to extend life are not always a benefit to patients and so must be used selectively.