From the beginning of the history of medicine, healers have had to deal with questions of ethics. However, the separate discipline of medical ethics has existed for less than 50 years, largely prompted by 20th-century advances in life-support technology. Today, the formulation of medical ethics has become a multidisciplinary endeavor, often involving teams that may include clergy, philosophers, scientists, and lawyers, as well as physicians and nurses.

The Hippocratic Oath, attributed to the ancient Greek physician Hippocrates, is one of the best-known statements of ethical practice. It required physicians to "abstain from whatever is deleterious and mischievous," seeking only the benefit of their patients. Doctors taking the oath swore: "I will give no deadly medicine to anyone if asked, nor suggest any such counsel; and in like manner I will not give to a woman a pessary (a device worn in the vagina) to produce abortion. With...