The moment at which human life begins has long been a subject of philosophical and ethical debate. But just as debated — and perhaps even more complex — is the question of exactly when life ends. 

From a legal perspective, death can be medically determined in one of two ways: through cardiopulmonary criteria, meaning the person’s heartbeat and breathing have ceased, or through neurological criteria, more commonly known as brain death. 

But brain death, medically defined as the irreversible cessation of all activity in the brain and brain stem, is often misunderstood or confused with other conditions, such as a persistent vegetative state. And even when accurately diagnosed, many physicians and ethicists are still not convinced that the death of the human brain truly equates with the full death of the person. 

Defining death 

John Haas, president of the National Catholic Bioethics Center, told Our Sunday Visitor that Catholic teaching, as explained in 2000 by Blessed Pope John Paul II, holds that death occurs when the soul is separated from the physical body. Although that’s not something science can measure definitively, there are ways to determine when it has taken place. 

“The Church has always held that it is the competency of health care professionals to determine when death has occurred, not that of the Church,” Haas said. “The empirical scientists cannot determine exactly the moment of death, so what we have to do is look for signs — indications of the fact that death has already occurred.” 

Traditionally, those signs were that a person’s heart was no longer beating or that he or she was no longer able to breathe. But with the advent of technology to keep a person’s organs functional, a new criterion was developed to mark the moment of death: the cessation of all brain function. 

The Pontifical Academy of Sciences has been called upon three times to review this method; in all cases, it has affirmed that the neurological criterion is a legitimate means of determining death. 

Those findings, and the endorsement of Pope John Paul, make the Church’s position on brain death clear, Haas said. Still, the Church is always open to scientific findings that would shed new light on the issue. 

“If, somehow, medical science shows that these tests are inadequate and can no longer be used to make judgments on death, the Church might have to change its position based on the scientific evidence,” he said. 

Findings raise doubt 

According to some experts, medical evidence already exists that calls into question the use of brain death criteria for determining death. 

Among the most notable Catholic critics of the neurological means for determining death is Alan Shewmon, a neurologist at UCLA Medical Center who served as a corresponding member of the Pontifical Academy for Life for 15 years. Shewmon told OSV that there may be consensus among doctors on brain death, but he finds that they often fail to give sound medical evidence to support this argument. 

“The general agreement that brain death is death is really pretty superficial,” he said. “It is very widespread; it is a huge international consensus, but when you start probing below the surface you find that there’s tremendous disagreement about the reason why it should be considered death.” 

For many years, Shewmon said, he and others in the medical community believed that the human brain was the body’s central organ, and without it the rest of the body would inevitably disintegrate over time, even when maintained through all available technological means. But a number of documented cases in the 1980s and ’90s led them to re-evaluate that belief. 

Cases of patients whose bodies were maintained after brain death showed that certain bodily functions, such as blood pressure and digestion, would eventually begin to stabilize. Brain-dead patients would also be able to achieve homeostasis, a natural balance of chemicals within the body. 

“What struck me most about those cases was not simply that they survived longer than a few weeks in this condition, but that they demonstrated some holistic properties that you could only ascribe to an organism as a whole and not simply to a collection of interacting organs,” Shewmon said. 

But such cases are not enough to convince all Catholic ethicists that someone is still living after brain death. 

“The fact is, lots of body parts can work well even after death,” said James DuBois, a professor at St. Louis University’s Albert Gnaegi Center for Health Care Ethics

“That’s the whole reason that organ transplantation is possible; you can remove the heart from one person … and then pop it in someone else’s chest and get it to start again,” DuBois told OSV. “That is remarkable, but it is no sign that the original owner is still alive.” 

‘Miraculous’ recovery? 

Media stories claiming that patients who have been diagnosed as brain dead have “miraculously” recovered have further muddled the issue. But experts agree that such cases, though they may sway public opinion, are greatly misleading. 

“So-called ‘recoveries’ from brain death are misnomers; they are really recoveries from coma that was misdiagnosed as brain death,” Shewmon said. Such misdiagnoses raise questions about the diagnostic criteria for brain death and their application, he said, but not the state of brain death itself. 

According to DuBois, cases of a patient being mistakenly diagnosed as brain dead — and thus, in his view, fully deceased — are a cause for serious concern. But these cases are entirely avoidable when care is taken by medical professionals and the tests for brain death are rigorously applied, he said. 

“Brain death is actually not that hard to determine in a reliable fashion,” DuBois said. “We definitely have the knowledge and technology to diagnose this in a trustworthy manner. When that doesn’t happen, it is just an outright medical error.” 

Scott Alessi writes from New Jersey.

Donor Dilemma (sidebar)

Beyond the philosophical debate over when life ends comes a practical, and more serious, concern — is it ethical to remove organs for transplant from a brain-dead patient? 

Organ donation, which has long received the support of the Church, requires the donor’s organs to be removed as close to the time of death as possible to ensure their viability for transplant. But if brain death is not truly death, as some argue, then removing their organs would be tantamount to murder, as it would become the actual cause of death. 

While the Church has supported the use of brain death criteria in determining that a body is ready for organ donation, Church leaders have also warned that there must be absolute certainty in the diagnosis before a transplant can begin. Pope Benedict XVI echoed this sentiment in a 2008 address to an international congress on organ donation. 

“In an area such as this, in fact, there cannot be the slightest suspicion of arbitration and where certainty has not been attained, the principle of precaution must prevail. … The principal criteria of respect for the life of the donator must always prevail so that the extraction of organs be performed only in the case of his/her true death,” the pope said.