Commentary on the Concept of Brain Death within the Catholic Bioethical Framework

I. INTRODUCTION

In light of increased criticism of the concept of brain death,1 Stephen Napier, a staff ethicist at the National Catholic Bioethics Center, set out to prove that the whole-brain death criterion serves as good evidence for death in the Catholic bioethical framework.2 He defends the validity of the concept of brain death, postulating that there is enough evidence to show that the loss of somatic integrative unity and coordinated biological functioning of a living organism justifiably equates with human death. The validation of this normative position, he asserts, only requires basic understanding of the philosophical anthropology largely accepted by the Catholic intellectual tradition.

Napier presents a line of reasoning characteristic of religious-based defenses of the concept of brain death. He begins with the premise that death is the rational soul's separation from the body. Since the rational soul is the principle of integrated functioning, making the organism what it is, the permanent loss of both holistic integration and the potencies distinctive to human beings indicates correctly and definitively that the soul is absent. Because the role of the brain is to integrate the functioning of the organism as a whole and considering that the brain is the seat of the rational potencies, it follows that when whole-brain function has been lost, this is a good indication that death has occurred.

Although Napier admits that the conclusion in his argument is valid if and only if its premises are true, he makes no effort to demonstrate that each premise is indeed true. In summarizing his reasoning, he states that the key inference in the argument is fairly simple: if the soul is present, then X should be present as well. X is not present; therefore, the soul is very likely not present either. He then goes on to assert that although a conclusion regarding the nonexistence of something, which in the context of brain death must be the permanence of the loss of consciousness and the associated departure of the soul, must be inferential, such an inference would not diminish the level of moral certitude of the conclusive judgment. Absolute certainty on these issues cannot be obtained, and therefore, only moral certitude is required. This implies that when enough evidence has been compiled that the soul is no longer present, then that amount of evidence is sufficient to qualify the act of determining death by neurological criteria as prudent.

Napier's defense that brain death equates with human death highlights some of the critical weaknesses of the rationale, endorsed by most religions, for the justification of the concept of brain death. It assumes without validation that (1) the irreversible pathophysiological conditions under which the soul would separate itself from the body have materialized in brain death, (2) the whole brain serves as the exclusive “integrator” of bodily functioning and is indeed the seat of the soul, and (3) the permanent loss of holistic integration and potencies is adequate proof of the soul's absence from the body.

II. THE SEPARATION OF BODY AND SOUL

It is indeed the teaching of the Catholic Church, and we would assume of most—if not all—other Judeo-Christian denominations that death is the separation of the body and the soul—a breakup of the fundamental wholeness of the organism. In the context of these teachings, Napier is correct when he writes that the soul not only drives the organism's development but also makes the organism be the kind of thing it is. In the case of human beings, having a rational soul is what makes them human. It provides human beings with species-typical rational potencies or powers such as the ability to think, will, intend, grasp moral goods, etc.3 In hylomorphic metaphysics, there is no living body without a soul and there is no soul without a body; the soul is the principle of life in a material body.4 Indeed, for Aquinas, since the soul is “united to its body as its form, it is necessary [that the soul] be in the whole body, and in each part of the body.”5 The hominization of man depends on the infusion with and presence of the soul in the body. It follows, then, that death must be defined as the absence of the soul. The Council of Vienna in 1311 affirmed this teaching on the soul when it stated that the rational soul is the form of the body, spiritual in nature, and produced by special creation when the organism is sufficiently developed to receive it.6 The latter implies that ensoulment, the exact moment in which the rational soul is infused into the body, is not necessarily the moment of conception since it is possible that the organism has not yet developed sufficiently for it to receive its soul. In Islam, for instance, biological life begins at conception, whereas human life begins when ensoulment takes place on the fortieth day of gestation. From a Catholic perspective, however, the prevailing and widely accepted theory among philosophers and theologians is that the soul enters the body at the very moment of conception. The fertilized egg, the chromosomes of which already carry the entire genetic information of the individual, is ready to receive the soul right from the first moment of its existence.7 This is a crucial concept not only because it defines the moral status of the early embryo as a human being but also because it indicates that the soul will only leave the body when the body is no longer able to contain the soul and starts the process of disintegration.8

This is an important philosophical position with implications for the definition of human death; it challenges the premise that the soul resides exclusively in the brain since the (irreversible) loss of whole-brain functioning does not necessarily lead to the conclusion that the body and the soul have separated from each other. It is only when the body is no longer capable of containing the soul that body and soul separate. In other words, as long as the precondition of a body continuing to function in an integrated manner has been met, there is no reason to assume that the unity between body and soul has been (prematurely) dissolved. It is precisely the claim of continued integrative functioning of the body that is at the heart of the brain death debate.

In order for Napier's position to be defensible, at least to the extent that judgments about life and death can be made with moral certitude, two prerequisites must be met. Reasonable arguments must be provided to support the premises that (1) the whole brain serves as the exclusive “integrator” of bodily functioning and (2) the brain is indeed the seat of the soul.

III. THE BRAIN AS THE INTEGRATOR OF BODILY FUNCTIONS

Brain death is associated with irreversible unconsciousness and the absence of spontaneous breathing; hence, its historical name of irreversible apneic coma. Mechanical ventilation enables patients to maintain respiratory function at a cellular level. Oxygen and carbon dioxide exchange enables vital organs to remain functional. It has long been argued that if in fact the brain is the sole integrator of all bodily functions, all integrative functioning must have ceased in brain dead patients. The President's Commission Report of 1981 said that the whole brain dead person lacks “systemic, integrated functioning” and therefore cannot be considered a living human being.9 The argument that circulatory arrest would follow rapidly after ventilator withdrawal was commonly presented (and still is) to demonstrate that integrative functioning has ceased. However, despite having impaired intracranial circulation, respiratory drive, and consciousness, patients diagnosed as brain dead continue to have a spontaneous heartbeat and whole body circulation, maintaining many integrated biological functions that are indistinguishable from those found in obviously living human beings.10 Among these vitally important biological functions are wound healing, body temperature regulation, maintaining homeostasis and hemodynamic stability, and reproduction.11 Such functions are indicative of the integrated functioning of the organism as a whole. Their continued presence raises legitimate scientific questions regarding the validity of the concept of brain death and effectively challenges the notion that the brain is the exclusive integrator of the human body.

As a result, many have argued that the concept of brain death based on the neurological criterion of irreversible cessation of all brain functions does not encompass the notion of irreversible loss of integrative unity of the organism as a whole and its regulatory functions essential for life.12 After a two-year period of research and discussion, The President's Council on Bioethics concluded that there is insufficient empirical and clinical evidence supporting the concept of brain death. Instead, the Council, after having rejected all previously advanced rationales for a neurological standard of death, switched to a new philosophical rationale for the validation of death by neurological criteria. It recognized that the “transition from living body to corpse is in some measure a mystery, one that may be beyond the powers of science and medicine to penetrate and determine with the finality that is possible when most human beings die.”13 Physiological evidence of continued somatic integration, according to the President's Council, does “not contradict the claim that total brain failure is a unique and profound kind of incapacitation—and one that may very well warrant or even morally require the withdrawal of life-sustaining interventions.”14 The Council claims that the limits to our ability to discern the line between life and death and the moral convictions that the bodies of deceased patients should not be ventilated and maintained as if they were still living human beings constitute a sound biological justification for today's neurological standard. The Council classifies these patients as deceased primarily based on the absence of spontaneous breathing. In order to justify this claim, the Council had to develop a philosophical rationale that in their own words provides “a more compelling account of wholeness that would support the intuition that after total brain failure the body is no longer an organismic whole and hence no longer alive.”15 It abandoned relying on the concept of “integration” and along with it the false assumption that the brain is the “integrator” of vital functions. As a result, the determination of whether “an organism remains a whole depends on recognizing the persistence or cessation of the fundamental work of a living organism.”15 Spontaneous breathing exemplifies the organism's self-preserving commerce with the world, and its absence proves that the needful openness to the world no longer exists, and therefore, the patient is dead. The significance of continued ability to breathe spontaneously is explained in the section “personal statements” in the President's Council's white paper. Gilbert Meilander postulates that the difference between the drive of hunger as an act of self-preservation and spontaneous breathing is that the latter is “more like a mechanical process that does not indicate the being's own attempt to engage its world.”16 This may seem self-evident in this particular example. However, the argument becomes significantly less compelling when considering physiological functions such as the maintenance of circulatory activity, body temperature, wound healing, and the body's continued drive to fight off infections. Taking continued circulation as an example, Martyn Evans plausibly asks why the ability to breathe spontaneously should count for life, whereas continued heartbeat does not.17 Implicitly, Napier's counterargument that these persistent physiological functions represent only subsystems becomes less plausible. Many of the vital functions that indicate the being's own attempt to engage the world are preserved in brain dead patients, and failure of any of these functions under clinical conditions other than “brain death” is commonly treated with medical interventions such as mechanical cardiac assist devices, vasopressors, permanent artificial pacemakers, organ transplants, etc.

Napier bases the conclusion that an organism's need for life-sustaining interventions caused by the loss of the organism's own ability to regulate vital functions is good evidence that the soul has departed the body on an analogy he borrows from James DuBois that equates brain death with decapitation.18 If cardiopulmonary activity in a decapitated body could be resuscitated, we would not still say that this body is a human being “but rather a human body whose respiration and cardiac systems are kept active by external means.”19 Without such support the body would disintegrate; therefore, the body has lost its ability to integrate itself—evidence that the soul is no longer present in the body. Napier's argument fails because decapitation constitutes a physiological state absolutely different from brain death since in the latter there is no permanent physiological separation of the body from the brain, as evidenced by the many well-preserved integrated bodily functions. In addition, many patients whose bodies have lost their own resources for maintaining vital functioning remain alive because of the use of mechanical assist devices. When Napier argues that in brain death it is the combination of a loss of rational functioning plus the loss of the body's resources to maintain vital functioning that constitutes human death, he provides no explanation or justification. Instead, as Alfonso Gomez-Lobo pointed out, the choice of whole-brain failure as a standard for death, even based on the general biological claim that the spontaneous drive to breathe, which is dependent on the brain, is necessary for life, remains a questionable one—as the existence of conscious, yet apneic patients shows.20 An even more compelling counterargument to the relevance of the inner drive to breathe in defining life is that in patients with lower brainstem lesions and during sleep in patients with Ondine's curse (sleep-induced central apnea), this inner drive is also absent. Alan Shewmon therefore concludes that “the inner drive to breathe is not a necessary feature of organismic wholeness”.21

IV. THE BRAIN AS THE EXCLUSIVE RESIDENCE OF THE SOUL

The Thomistic view that it is the soul that makes the organized body be a unique entity is widely accepted in Abrahamic religious traditions. The soul is, as Napier pointed out, a principle of organization and development, making a thing be what it is. Napier, however, persists in arguing that the brain is the exclusive residence of the soul despite compelling arguments to the contrary. Shewmon provided sound arguments in support of the premise that organic integration is inherently nonlocalizable; “integrative unity is almost by definition diffusely present throughout a complex organism.”22 He defined the essence of integrative unity as the “anti-entropic mutual interaction of all the cells and tissues of the body, mediated in mammals by circulating oxygenated blood.”23 As indicated earlier, the President's Council on Bioethics also abandoned the concept of “integration” and with it the false assumption that the brain is the “integrator” of vital functions.24 Although Napier resists accepting the higher brain death criteria, the loss of upper cortical functioning appears more logically consistent with the loss of what makes us human—the possession of a rational soul. Napier provides two reasons for his objection to higher brain death. First, acceptance of this concept would produce the socially unacceptable consequence of permitting society to treat breathing individuals as dead. Second, it would conflate the death of a part of the organ with the death of the organism.25 He argues that the cerebrum, in contrast to the whole brain, is an organ and does not have the quasi-executive function of maintaining the life of the organism as a whole. Therefore, whole-brain death equates to human death and death of the cerebrum does not. Napier's position in regard to the first point is unmistakably true. His second point can only be true if the whole brain is indeed the sole executor of integrative functions, and that, as we have argued in this paper, is inconsistent with empirical findings.

V. THE PERMANENT LOSS OF HOLISTIC INTEGRATION AND POTENCIES AS PROOF OF THE SOUL’S ABSENCE FROM THE BODY

In this paper, we have provided reasonable empirical and philosophical arguments to show that patients in irreversible apneic coma, now commonly diagnosed as brain dead, have not lost holistic integration since many integrated physiological functions continue to be present. But what about potencies? One could argue that the irreversible absence of the rational potencies that distinguish us from other species is indicative that we have lost “personhood,” and, therefore, have lost our soul. As these rational capacities grounded in the operations of the upper brain have been permanently lost, the patient has died and is no longer truly a person. A second argument, Napier points out, is that if a person lost the capacity for consciousness, sentience, or intentionality, then this person has lost her moral status as a human being. As outlined in an earlier segment of this paper, Napier concluded that higher brain death cannot be supported because it leads to the socially unacceptable consequence of allowing breathing individuals to be buried. Furthermore, the cerebrum does not serve a “quasi-executive function” of maintaining the life of the organism as a whole.

Neither argument is either scientifically or philosophically sound. Higher brain criteria are not acceptable because of the intrinsic problems with the concept of consciousness. Human consciousness has two components: arousal and content of consciousness. The content of consciousness includes cognitive and affective mental functions and whatever a person is aware of at that moment (active inner awareness), as well as private self-conscious experiences, memories, and acquired knowledge, which may remain latent in memory but inactivated. In the definition of brain death, it is assumed that consciousness in all its forms is lost. Nevertheless, none of the tests required to document “brain death” tests for the destruction of the cerebral hemispheres.26 In fact, there are no criteria for the diagnosis of the loss of content of consciousness (awareness) in “brain-dead” patients since consciousness is, by nature, a subjective experience.27 These clinical realities should nullify the value of so-called higher brain death, but they should be equally devastating for the concept of whole-brain death. An even greater challenge to both concepts is that evidence from human brain imaging studies, as well as from neurological damage in animals and humans, suggests that some form of consciousness can survive the brain damage that commonly causes permanent loss of consciousness. Neuroscientific evidence indicates that raw emotional or affective feelings (primary process affects) can exist without cognitive awareness of those feelings.28

VI. IMPLICATIONS FOR PRACTICE

We have argued that if the soul is the principle of integrated functioning that makes the organism what it is, and if the soul is unlikely to reside exclusively in the brain, then there is no good evidence that the body and the soul have separated and, therefore, that the person is dead. Our conclusion would still allow it to be morally appropriate to withdraw life support, which allows the disease process to take its course. However, our conclusion does have significant implications for the moral acceptability of heart-beating organ procurement practices. Pope Benedict XVI stated that vital organs can be extracted “ex cadavere” [from a dead body] if and only if the donor's true death can be certified beyond a doubt.29 If there is moral uncertainty about Napier's conjecture that the soul is only seated in the brain, then such uncertainty has a profound moral implication because heart-beating organ procurement becomes effectively either an act of active euthanasia or an act of physician-assisted death.30 Finally, and perhaps most importantly, the inaccurate diagnosis of brain death puts a large subset of cases of brain injury currently regarded as irreversible at increased risk of being denied appropriate medical care that, if provided in a timely manner, could result in the patient's return to a normal life.31

VII. CONCLUSION

One must earnestly question Napier's confidence in the validity of the underlying premises (i.e., the brain as the seat of the soul and the exclusive integrator of all functions of the whole brain) for the position that the loss of whole-brain function indicates death. The reason why the argument in support of equating brain death to human death fails is not, as Napier claimed, because of any misunderstanding of the philosophical anthropology largely accepted by the Catholic intellectual tradition and not because of the suggestion that the claims made by opponents of the concept of brain death are “slightly overblown.” This argument falls through because empirical facts and sound philosophical arguments seriously challenge the contention that whole-brain death is good evidence that death has occurred. Thus, not enough evidence exists to determine with moral certitude that whole-brain death equates with human death.

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