Alfie Evans died on April 28 at 23 months old, and the British boy’s case has reopened old questions: Who has the right to veto further care? What happens where conflicts of interest arise, as when Terri Schiavo’s husband fought to withhold water and nutrition while living with another woman and standing to inherit over $700,000 from his wife’s medical trust fund? And most fundamentally: What is life, or quality of life?

“Life” is easy to define intuitively, but more challenging to define for patients whose ailments primarily affect the brain. If life depends on self-awareness, are people with Alzheimer’s, or who are mentally ill and suffer from delusions, dead? If it depends on the ability to perform given “activities of daily living”—or any activities of daily living at all—are those with disabilities dead?

In 1968, bioethicist Henry Beecher’s committee published its proposed answers to those questions in the Journal of the American Medical Association, focusing on “irreversible destruction of the brain” as equivalent to death. The committee gave two reasons for its answer: first, to relieve the financial and social burden of care it viewed as futile, and second, to address controversies about obtaining organs for transplant. A New Yorker article states that an earlier draft spoke more bluntly: “There is great need for the tissues and organs of the hopelessly comatose in order to restore to health those who are still salvageable.”

Such attitudes have long made the organ-procurement world both hero and villain to some, and the same article quoted Peter Singer—the Princeton bioethics professor who has attempted to justify infanticide—as stating that brain death is “a concept so desirable in its consequences that it is unthinkable to give up, and so shaky on its foundations that it can scarcely be supported. … [It is] an ethical choice masquerading as a medical fact.” A recent movement has questioned the idea of brain death, and a New Jersey law allows families with religious objections to insist that doctors not declare a patient dead until the patient’s heart stops. The family of Jahi McMath, a teenager originally declared brain-dead in California, used such an exception to continue her care in New Jersey—for over four years.