1968 was a year of upheaval, perhaps best remembered by Americans for the assassinations of Martin Luther King, Jr., and Robert Kennedy, and by Catholics for the promulgation of Humanae vitae. But the unobtrusive coining of a new definition should be included with these momentous events, for it changed medical practice by shifting the boundary between life and death. In 1968 the Harvard Medical School Ad Hoc Committee introduced the oxymoronic definition “irreversible coma as a new criterion for death,” classifying deeply comatose patients as corpses for both medical and legal purposes.

For decades Catholic proponents of “brain death” have claimed that moral certainty exists that “brain-dead” patients are, in fact, dead, and therefore their organs may ethically be harvested. However, this claim has become increasingly controversial as empirical medical evidence has mounted that “brain-dead” patients are alive. In the words of Courtney Campbell (p 344), “A presumed stable consensus has given way to a ‘crisis’ in Catholicism over the status of neurologic criteria for death.”

In his oft-cited Address to the 18^th International Congress of the Transplantation Society in the year 2000, Pope Saint John Paul II stipulated that for the organs of “brain-dead” patients to ethically be harvested, moral certainty must exist that these persons are actually dead. He wrote:

Moral certainty is considered the necessary and sufficient basis for an ethically correct course of action. Only where such certainty exists, and where informed consent has already been given by the [organ] donor or the [organ] donor’s legitimate representatives, is it morally right to initiate the technical procedures required for the removal of organs for transplant.

In that Address John Paul II did not expound what qualifies as “moral certainty,” but he went into greater detail in an earlier Address to the Tribunal of the Roman Rota on February 4, 1980. At that time he made special appeal to Pope Pius XII, who “declared in an authentic way the canonical concept of moral certainty in the allocution addressed to your tribunal on October 1, 1942.” That 1942 Allocution provides a foundational articulation of moral certainty for Catholics (English translations cited from The Canon Law Digest, Supplement 1948, by T. Lincoln Bouscaren). In it, Pius XII contrasts three types of certainty: quasi-certainty, absolute certainty, and moral certainty.

The following example illustrates quasi-certainty. My friend, who has a two-car garage, asks me to open his garage door. There are two garage door buttons: one opens his garage door, while the other opens his wife’s garage door. I seem to recall him pressing the top button in the past. Thinking, “I’m sure it’s the top button,” I confidently press it. His wife’s garage door opens! Sheepishly, I close her garage door and then press the bottom button. My basis for pressing the top button was a vague memory which proved to be incorrect. I had no concrete evidence to support my decision, and thus my confidence was unfounded. Pius XII wrote of such quasi-certainty that “common speech often designates as certain a cognition which strictly speaking does not merit to be so called, but should rather be classed as a greater or lesser probability, because it does not exclude all reasonable doubt, but leaves a foundation for the fear of error.”

In contrast, Pius XII wrote of absolute certainty that it excludes “all possible doubt as to the truth of the fact and the unreality of the contrary.” The proposition that 2 + 2 = 4 is an example of absolute certainty. Adding 2 and 2 always equals 4, throughout time and in all circumstances. Absolute certainty is most readily attainable in the fields of mathematics and metaphysics; achieving this level of certainty in the complex reality of daily life is typically not possible.

Between quasi-certainty and absolute certainty is moral certainty. Unlike quasi-certainty, moral certainty eliminates reasonable doubt. But unlike absolute certainty, moral certainty admits the absolute possibility of being wrong. The degree of moral certainty necessary before making a decision depends upon the consequence of potentially being wrong: the graver that consequence, the greater the degree of moral certainty required. If the consequence of being wrong is extremely grave, such as an innocent person’s life being taken, the greatest degree of moral certainty is required.

A proper understanding and application of moral certainty has been crucial for the issue of abortion. There is a historical debate among Catholic philosophers and theologians concerning when God infuses the rational soul into a newly formed human life. The prevailing opinion today is that the rational soul is infused at the moment of conception. However others, including Saint Thomas Aquinas, have claimed that early human life receives a succession of souls: vegetative, then sensitive, and finally rational. If this were true, then only after the infusion of the rational soul would early human life become personal and therefore deserving of human rights.

Nonetheless, the Catholic Church has always made clear that despite this philosophical exploration, pragmatically the unborn child should always be treated as a human person. In Donum Vitae the Congregation for the Doctrine of the Faith wrote:

The Magisterium has not expressly committed itself to an affirmation of a philosophical nature, but it constantly reaffirms the moral condemnation of any kind of procured abortion. This teaching has not been changed and is unchangeable.

Although we cannot prove that unborn children possess rational souls at the moment of conception, we have an ethical obligation to err on the side of caution and treat them as human persons. This is because to do otherwise risks the intentional killing of innocent human persons. John Paul II wrote in Evangelium Vitae:

Furthermore, what is at stake is so important that, from the standpoint of moral obligation, the mere probability that a human person is involved would suffice to justify an absolutely clear prohibition of any intervention aimed at killing a human embryo. Precisely for this reason, over and above all scientific debates and those philosophical affirmations to which the Magisterium has not expressly committed itself, the Church has always taught and continues to teach that the result of human procreation, from the first moment of its existence, must be guaranteed that unconditional respect which is morally due to the human being in his or her totality and unity as body and spirit. . . .

Thus the Catholic Church’s application of moral certainty to the issue of abortion affirms that when the consequence of potentially being wrong is the taking of an innocent human life, there is a moral obligation to err on the side of caution. Following the logic employed with abortion, if reasonable doubt exists whether “brain-dead” patients are truly dead, we should err on the side of life and treat “brain-dead” patients as living human persons. Even secular “brain death” proponents advocate for this approach. Neurologists Ali Daneshmand and David Greer have written (p 167): “This [the determination of death] is truly one of the few areas in medicine where there is no room for error; if there is any doubt as to whether a patient is dead or not, clinicians must err on the conservative side, not declaring death until there is irrefutable and consistent evidence to support the determination.”

The human person is the substantial union of body and soul, a body-soul composite. The soul is the principle of integration of the body, holding it together and allowing it to function as a coherent whole. Death occurs when the soul leaves the body. This moment cannot be directly observed because the soul is immaterial, but can be inferred by the consequences of the soul’s absence. When the soul leaves the body, the body begins to dis-integrate, to decompose. In contrast, persistent bodily integration is evidence that the body’s principle of integration (the soul) is present. John Paul II wrote in his 2000 Address to the Transplantation Society:

The death of the person is a single event, consisting in the total disintegration of that unitary and integrated whole that is the personal self. It results from the separation of the life-principle (or soul) from the corporal reality of the person.

The following is a brief, non-exhaustive list of medical evidence which supplies reasonable doubt that patients declared “brain-dead” are actually dead. While reading, bear in mind that among the stipulations made by John Paul II in his 2000 Address for “brain death” to potentially be considered valid, there must be “complete and irreversible cessation of all brain activity” (emphasis added) and evidence that “the individual organism has lost its integrative capacity” (emphasis added).

• A “brain-dead” patient is warm and pink, has supple flesh, and has a heartbeat, signs which in centuries past would unequivocally have been equated with life.
• A “brain-dead” patient may flush, sweat, and exhibit spontaneous and reflex movements.
• “Brain-dead” pregnant women can gestate and give birth to their children.
• Persistent function of a part of the brain called the hypothalamus is considered compatible with a diagnosis of “brain death” according to the current medical guidelines. At leasthalf of patients declared “brain dead” have persistent function of this part of the brain. Even Catholic “brain death” proponents acknowledge that persistent hypothalamic function is a clear violation of John Paul II’s stipulation that all brain activity must be absent.
• Over 170 cases have been collected of “chronically brain-dead” patients who survived weeks, months, or even years after a diagnosis of “brain death.” Instead of decomposing, these patients demonstrated diverse integrative functions such as fighting infection, healing wounds, and maintaining body temperature.
• “Chronically brain-dead” children demonstrate proportional physical growth, and in rare instances undergo sexual maturation.
• The “brain-dead” patient “TK” survived for 20 years despite having no identifiable brain tissue, even under microscopic examination, at his autopsy.
• Some patients, such as Jahi McMath, have been declared “brain dead” using the current medical guidelines but were subsequently found to be neither 1) dead nor 2) “brain dead.” The true number of misdiagnosed patients is unknown because typically either life-support is stopped or the patient’s organs are harvested.

It is worth noting that, in light of this medical evidence, a significant number of secular “brain death” proponents do not even claim that “brain death” represents biological death. Nonetheless, they hold that organ harvesting from “brain-dead” patients is ethically legitimate, sometimes with the stipulation that the public should be informed that organs are being harvested from still-living patients. Within this camp are those claiming “brain death” is a legal status, a category designated by law which may or may not correspond to objective reality, such as in this statement by physicians Christos Lazaridis and Fernando Goldenberg: “Death by neurologic criteria is a state, along the spectrum of devastating brain injury, sufficient for a person to be assigned the legal status of death.” (p 207) Others claim that “brain death” is a legal fiction which unequivocally does not correspond to reality, but rather “allows us to treat persons who are not dead as if they are dead.” This echoes the claim of the 1968 Harvard Medical School Ad Hoc Committee that “brain-dead” patients may be considered “for all practical purposes dead.” The 2008 President’s Council on Bioethics, while defending the notion of “brain death,” forthrightly admitted it does not represent the end of somatic integration (i.e., biological death), writing that “the brain is not the integrator of the body’s many and varied functions…. [N]o single structure in the body plays the role of an indispensable integrator….”

Paradoxical situations can arise from this medical-legal disconnect, such as a patient being alive in one state and dead in another. Jahi McMath was declared “brain dead” in California on December 12, 2013, and a death certificate was issued. At that point the hospital was no longer legally obligated to care for Jahi apart from court-ordered ventilation, and in fact food and medication were withheld from her for 3 weeks. With the coroner’s permission Children’s Hospital of Oakland released Jahi on a ventilator to the care of her mother, who flew her to New Jersey, which allows a religious-based exemption from a declaration of “brain death.” Upon crossing the state line, Jahi was legally resurrected from the dead. She survived another 4 years and 6 months before dying from abdominal complications, at which time a second death certificate was issued.

Setting aside for a moment whether “brain death” actually represents the death of the human person, there is also doubt whether it can be reliably determined in practice. Widely acknowledged testing variability exists not only between countries, but within the United States also between states and among individual hospitals. For example, in order to declare a person “brain dead” according to the 2010 American Academy of Neurology guidelines, confounding factors such as low blood pressure (hypotension) and low body temperature (hypothermia) must be excluded. Failure to exclude these factors could lead to a “false positive” determination that a patient meets criteria to be declared “brain dead.” But in a 2016 survey of 492 hospital policies in the United States, only 56% mandated that hypotension be excluded prior to evaluation for “brain death,” and only 79% required exclusion of hypothermia.

Given this evidence, let’s examine three pivotal claims about moral certainty from Pius XII’s 1942 Allocution to consider whether moral certainty exists that “brain-dead” patients are dead. First, Pius XII states that examination of a large body of evidence may be necessary before moral certainty can be achieved. This seems particularly appropriate for a complex subject such as “brain death.” Pius XII wrote:

Sometimes moral certainty is derived only from an aggregate of indications and proofs which, taken singly, do not provide the foundation for true certainty, but which, when taken together, no longer leave room for any reasonable doubt on the part of a man of sound judgement.

When “brain death” was first defined in 1968, there was no empirical medical evidence whether this new concept of death corresponded to reality or not. Nonetheless, the concept was immediately put into practice to justify organ harvesting from “brain-dead” patients. Today, over half a century later, substantial medical evidence has accumulated which strongly suggests that “brain-dead” patients are alive, not dead. The aggregate of medical information, rather than verifying the validity of “brain death,” calls it into question.

Second, moral certainty does not exist when a reasonable person can hold the contrary position and posit a feasible argument which may even be considered probable. Pius XII wrote that moral certainty:

. . . does not exist if there are on the other side, that is, in favor of the reality of the contrary, motives which a sound, serious, and competent judgement pronounces to be at least in some way worthy of attention, and which consequently make it necessary to admit the contrary as not only absolutely possible but also in a certain sense probable.

Thus moral certainty cannot exist that “brain-dead” patients are dead when a broad range of scholars with diverse nationalities and world views, spanning the disciplines of medicine, bioethics, philosophy, and law, hold that “brain-dead” patients are biologically alive. This reality makes it necessary to admit at least the possibility that “brain-dead” patients are alive, and arguably the probability that they are alive.

Finally, if moral certainty truly exists, then persons should eventually arrive at the same conclusion. The presence of conflicting conclusions should prompt a closer examination of the evidence, with the goal of arriving at the truth. Every effort should be made to reconcile differences of opinion to avoid undermining public confidence. Pius XII wrote:

Now, as the objective truth is one, so too moral certainty objectively determined can be but one. . . . [If a judge entertains contradictory conclusions] it should induce him to undertake a further and more accurate examination of the case. . . . In any event, the confidence of the people . . . demands that, if it is at all possible, such conflicts between the official opinion of judges and the reasonable public opinion of well educated people should be avoided and reconciled.

Again, strong disagreement exists among well-educated people whether “brain-dead” patients are alive or dead. New articles critical of “brain death” are regularly published in both the popular and scholarly literature. Moreover, the general public is losing confidence in the notion of “brain death,” as evidenced by families of “brain-dead” patients filing lawsuits claiming their loved ones were wrongly declared dead using “brain death” criteria. This is particularly true for minorities, who know too well that the law, government, and even religious communities have frequently been wrong in the past regarding who count as human persons.

Regardless of what may have been true in the past, moral certainty that “brain-dead” patients are dead does not exist in the year 2024. In fact, it could be argued that if moral certainty exists, it is that “brain-dead” patients are alive. Given what is at stake, the life of an innocent human person, Catholics and all people who uphold the sacredness of human life should err on the side of caution and presume that “brain-dead” patients are living human persons, in the same way that the Catholic Church errs on the side of caution for the unborn child. Recognizing that “brain-dead” patients are alive does not imply that they must be maintained indefinitely on life support. Extraordinary means are not morally obligatory, and “brain-dead” patients can be allowed to die naturally. However, their lives cannot be directly ended through the act of organ harvesting. As good-faith dialogue on “brain death” continues among Catholics and society at large, the concept of moral certainty compels us to oppose the utilization of “brain death” criteria in clinical practice. Let us pray with Pius XII:

May the eternal Sun of Justice enlighten the earth and its rulers; and may He, for the glory of God and of the Church and of the Christian people, accompany [us] at every step in the quest of that reality and truth which sets the face of justice at rest in the tranquil repose of moral certainty.