Americans seem to be increasingly concerned with decisions about death and dying. Why is a subject once thought taboo now so frequently aired by the popular media, debated in academic forums and professional societies, and litigated in well-publicized court cases? Perhaps it is because death is less of a private matter than it once was. Today, dying more often than not occurs under medical supervision, usually in a hospital or nursing home. Actions that take place in such settings involve more people, and the resolution of disagreements among them is more likely to require formal rules and means of adjudication. Moreover, patients dying in health care institutions today typically have fewer of the sources of nonmedical support, such as family and church, that once helped people in their final days. Also important, no doubt, are the biomedical developments of the past several decades. Without removing the sense of loss, finality, and mystery that have always accompanied death, these new developments have made death more a matter of deliberate decision. For almost any life-threatening condition, some intervention can now delay the moment of death. Frequent dramatic breakthroughs-insulin, antibiotics, resuscitation, chemotherapy, kidney dialysis, and organ transplantation, to name but a few-have made it possible to retard and even to reverse many conditions that were until recently regarded as fatal. Matters once the province of fate have now become a matter of human choice, a development that has profound ethical and legal implications. Moreover, medical technology often renders patients less able to communicate or to direct the course of treatment. Even for mentally competent patients, other people must usually assist in making treatment decisions or at least acquiesce in carrying them out. Consequently, in recent years there has been a continuing clarification of the rights, duties, and liabilities of all concerned, a process in which professionals, ethical and legal commentators, and-with increasing frequency-the courts and legislatures have been involved. Thus, the Commission found this an appropriate time to reexamine the way decisions are and ought to be made about whether or not to forego life-sustaining treatment. For example, may a patient's withdrawal from treatment ever be forbidden? Should physicians acquiesce in patients' wishes regarding therapy? Should they offer patients the option to forego life-sustaining therapy? Does it make any difference if the treatment has already been started, or involves mechanical systems of life support, or is very costly?