Death by the Brain Criterion: A Response to Shewmon

Nicholas Tonti-Filippini

March 24, 2013

[Abstract: In his critique of my article on death by the brain criterion, Alan Shewmon misrepresents my position in two very significant ways and much of his criticism is thus misplaced.

First, Shewmon makes a fairly simple philosophical error in mistaking necessary and sufficient conditions for a person to be alive. I have never claimed or implied that the brain is the master organ of the body. Rather, I have claimed that the function of the brain, like circulation (ordinarily the function of the heart) is necessary for the body to be maintained as a dynamic unity.

Second, Shewmon claims that I have held that the view that accepts the brain criterion is the only view permissible within the Church. In fact a close reading of the article shows that I described alternative views to that as “views within the Church” including his own, and I was careful to describe Pope John Paul II as permitting the diagnosis of death by the brain criterion, not that he prescribed that view alone as a matter of faith and doctrine.

I do, however, take issue with Shewmon’s account of integration as not being based on the Tradition and the doctrine that the substance of the rational or intellectual soul is of itself and essentially the form of, and informs, the unity that is the human body. Shewmon’s account of “integration” has no apparent basis in either an anthropology that is consistent with the Tradition, nor in any accepted philosophy in that respect. His notion of “integration” lacks a concept of dynamic unity in which the parts of the body are functionally related and in intercommunication with each other. The oddity of this is evident in Shewmon’s account of the “brain in a vat” and his account of life continuing after death as determined by the brain criterion. Those accounts would have a person able to continue as two isolated individual lives.]

1. Death is the Separation of the Soul

In his criticism of my defence of the position on death by the brain criterion explained by Pope John Paul II in 2000, Dr. Alan Shewmon credits me with what he calls

the orthodox “whole brain” criterion which is based on the dual conceptual-physiological grounds that (1), death is a cessation of integrative unity of an organism, and (2) for humans, and higher animals, the brain is the master organ that integrates all the parts of the body.1

Let me say from the outset that this is not my view and nor do I think that it adequately represents the view explained by John Paul II.

This representation of what Shewmon calls the orthodox “whole brain" criterion confuses necessary and sufficient conditions. If I were to say that the circulation of the blood is necessary for the human body to still be alive, no one would hold that I therefore held that the heart was the master organ that integrates all the parts of the human body. To say that a function of an organ is necessary for there to be a living body is not to say that that organ is the master organ.

There is a variety of organs that are needed to sustain life in a body. For diagnostic purposes, medical practice has focused on two particular functions as being vital, that is necessary, for the life of the individual human body to continue, the heart or the brain. The Pontifical Academy for Science addressed the issue of doubts about death by the brain criterion in 2006. The Academy argued for the following conclusions:

  • There is not more than one form of death.
  • So-called “brain death” means the irreversible cessation of all the vital activity of the brain (the cerebral hemispheres and the brain stem). This involves an irreversible loss of function of the brain cells and their total, or near total, destruction. The brain is dead and the functioning of the other organs is maintained directly and indirectly by artificial means.
  • Loss of all brain function is death because it is associated with loss of integration of the body as a single whole.
  • Death by the brain criterion can only be diagnosed with certainty if there is evidence that there is no blood supply to the brain, and that the “established clinical criteria” was in most circumstances a reliable indicator for the loss of all brain function.2

To say that loss of brain function is associated with loss of integration of the body as a single whole is not to say that brain function alone causes integration of the body, only that it may be a necessary element. A model house built from a pack of playing cards has a form and structure as a card house until one of the bottom cards is removed when the whole structure collapses. That does not make the removed card the master card. It is one of many cards that could have been removed so that the structure lost its form.

The statement by the Academy that there is not more than one form of death is important. Death is the separation of the soul. Because of the advent of technology such as ventilators and drugs known as inotropes, it appears that some semblance of life can be maintained even if the essential dynamic unity that we know as bodily life has been lost following separation of the soul.

The inclusion, by the Academy, of evidence of a lack of blood supply to achieve certainty indicates a significant difference between the medical cultural context in which Shewmon operates and the dominantly European cultural context of the Academy, and that may explain some of Shewmon’s difficulties with the Academy. Shewmon made claims about functions continuing after death has been diagnosed by the brain criterion that would not have accorded with evidence of irreversible loss of all brain function, but might have been consistent with death by the brain criterion in the context of the lesser standards applying in the US and known as the Mode of Being view. More about this later.

Use of the phrase “brain death” is unfortunate because it implies that there are different forms of death. In our tradition, since the doctrine was defined by the Council of Vienne,3 we have understood that the soul is what gives form to, and informs, the matter in the unity that is our human body:

Adhering firmly to the foundation of the catholic faith, other than which, as the Apostle testifies, no one can lay, we openly profess with holy mother church that the only begotten Son of God, subsisting eternally together with the Father in everything in which God the Father exists, assumed in time in the womb of a virgin the parts of our nature united together, from which he himself true God became true man: namely the human, passible body and the intellectual or rational soul truly of itself and essentially informing the body…
[W]e reject as erroneous and contrary to the truth of the catholic faith every doctrine or proposition rashly asserting that the substance of the rational or intellectual soul is not of itself and essentially the form of the human body, or casting doubt on this matter.4

In accordance with this doctrine, John Paul II said,

The death of a human being consists in the total disintegration of the unitary and integrated whole that is the personal self. Although death is an event which cannot be directly identified, biological signs or ‘clinical marker’ that inevitably follow can be recognised with increasing precision. These clinical markers indicate the irreversible loss of the integrated and coordinated life of the person as a single living organism.5

It is important to note that the doctrine proclaimed by the Council refers to the soul as both forming and informing the unity that is the body. It is probable that the source for this aspect of the doctrine was St Thomas Aquinas.6  However, the doctrine is also thought to have been implied by Genesis 2:7: “then the Lord God formed man of dust from the ground, and breathed into his nostrils the breath of life; and man became a living being.”

2. Defining Integration

In his critique, Alan Shewmon, asserts that I have not provided a definition of what integration means in this context.7  In the original article, I had written,

We can take from the doctrine proclaimed at the Council of Vienne that the ongoing causative effect of the soul is its informing the body. Therefore the type of integration which is relevant is a communication of information to all parts of the body that keeps the body united and functioning as a single whole.8

This would seem to be consistent with John Paul II's teaching that death is the separation of the soul from the body; that it consists in the total disintegration of the unitary and integrated whole that is the personal self; and that therefore what we are looking for is evidence or “clinical markers” that indicate the loss of the integrated and coordinated life of the person as a single living organism in which the soul forms and informs the matter to maintain the unity of the body. The relationship between soul and body is thus dynamic.

In defending John Paul II’s acceptance of determining death by the brain criterion, I proposed only that the loss of all brain function is a state of loss of dynamic unity of the body, not that the brain is the master organ, as Shewmon expresses it. As indicated above, the same claim can be made about loss of circulation. When the heart stops beating there is also a loss of integration, largely because vital organs such as the brain permanently cease to function soon after and the parts of the body have no means of communication if there is no circulation. The heart and the lungs perform an essential function in keeping the organs of the body alive, though the latter die at different rates when the heart stops beating.

The problem a faithful physician has in medically determining that death has occurred is that the soul is not observable. The doctrine, however, implies that the effects of the soul may be observable. When we observe the integrated functioning of the organic unity that is the human body, as a matter of faith we are confident that that body is formed by a human soul, and therefore that the human soul must be present. Though there is no event that marks the separation of the soul at death, what the physician observes is the disintegration of the body that results from that separation. Loss of a communicative relationship between the parts of the dynamic unity that is the body would indicate loss of the dynamic role of the soul.

Pope John Paul II, expressed this in the following way:

It is helpful to recall that 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 death of the person, understood in this primary sense, is an event which no scientific technique or empirical method can identify directly.
Yet human experience shows that once death occurs certain biological signs inevitably follow, which medicine has learnt to recognize with increasing precision. In this sense, the "criteria" for ascertaining death used by medicine today should not be understood as the technical-scientific determination of the exact moment of a person's death, but as a scientifically secure means of identifying the biological signs that a person has indeed died.9

John Paul II does not proclaim doctrinally the diagnosis of death by the brain criterion. His words are more cautious. He gives permission for health practitioners to adopt the neurological criterion:

the criterion adopted in more recent times for ascertaining the fact of death, namely the complete and irreversible cessation of all brain activity, if rigorously applied, does not seem to conflict with the essential elements of a sound anthropology. Therefore a health-worker professionally responsible for ascertaining death can use these criteria in each individual case as the basis for arriving at that degree of assurance in ethical judgement which moral teaching describes as "moral certainty". This moral certainty is considered the necessary and sufficient basis for an ethically correct course of action.10

It is, however, open to a faithful Catholic to challenge the medical empirical grounds on which the Pope based his judgement.

Nevertheless, one would reasonably expect that challenge to be based on accepting that the separation of the soul at death results in loss of integration and that the latter means a loss of dynamic unity in which not all the remaining parts of the body are unified through being interrelated to one another in a communicative sense (forming and informing). My concern with Shewmon’s position is not that he rejects Pope John Paul II’s permission for health professionals to use the brain criterion to determine death - it is open to him to challenge the empirical grounds for that permission - but that he does not accept the notion of integration that the Pope engaged which implies dynamic unity of the organism that is the life of the person. Shewmon’s notion of integration does not require that unity.

Shewmon’s key point is that his notion of integration is more in line with reality. However his distinction between life-constituting and life-sustaining types of integration is problematic.

A difficulty that I have with Alan Shewmon’s treatment of integration is that he seems to considerate it sufficient that some parts of the body remain related to other parts of the body for the body to be considered integrated. This is not unity of the body in the sense implied by the doctrine proclaimed at Vienne, a unity that is a result of the soul forming and informing the matter. He also criticizes me for thinking in terms of levels of integration. That may have been a misunderstanding in that I conceded that what he refers to as “integration” was an acceptable meaning of the word and that could be taken to imply different levels of integration. But for the purposes of understanding what integration must mean in the context of understanding the concept as a necessary element of being a living human person, his meaning will not do at all, because the concept must at least imply a dynamic intercommunicative unity between the parts. We take it that that dynamic unity, taking its form from the immortal soul, persists from the formation of the zygote until the soul separates from the body at death, even though in both Donum Vitae and Dignitas Personae the Congregation of the Faith is a little more circumspect about declaring that the zygote has a soul. It instead poses a question:

Certainly no experimental datum can be in itself sufficient to bring us to the recognition of a spiritual soul; nevertheless, the conclusions of science regarding the human embryo provide a valuable indication for discerning by the use of reason a personal presence at the moment of this first appearance of a human life: how could a human individual not be a human person?11

Shewmon devotes a great deal of space to his own theoretical analysis of integration, contrasting life-constituting and life-sustaining “types” as he expresses it and envisioning integration as being on two different axes. The analysis is novel and interesting but ungrounded. There is no anthropological starting point and no apparent basis in existing philosophical or theological perspectives within the Tradition.

To try find an answer to this question of death that is consistent with our Tradition or, at least, a development of the Tradition, we do need to work from the point of view of trying to understand theologically what happens at death and what it is to understand what an individual life is from the single cell zygote until death: we need to develop an anthropology that makes sense of what it is to have an immortal rational soul that forms and informs the matter so as to be the unity that is a human person, as we understand the latter to be from the doctrine proclaimed at the Council of Vienne, and renewed many times since. At Vienne the doctrine was not presented as a philosophical thesis but instead offered a theological starting point by being based upon John’s Gospel:

When Jesus had received the vinegar, he said, "It is finished"; and he bowed his head and gave up his spirit. 31 Since it was the day of Preparation, in order to prevent the bodies from remaining on the cross on the sabbath (for that sabbath was a high day), the Jews asked Pilate that their legs might be broken, and that they might be taken away. 32 So the soldiers came and broke the legs of the first, and of the other who had been crucified with him; 33 but when they came to Jesus and saw that he was already dead, they did not break his legs. 34 But one of the soldiers pierced his side with a spear, and at once there came out blood and water. 35 He who saw it has borne witness--his testimony is true, and he knows that he tells the truth--that you also may believe.12

Linked to this Gospel account in our Tradition is the teaching that

Jesus "descended into the lower parts of the earth. He who descended is he who also ascended far above all the heavens." The Apostles' Creed confesses in the same article Christ's descent into hell and his Resurrection from the dead on the third day, because in his Passover it was precisely out of the depths of death that he made life spring forth.13

In summary, the Catechism expresses the teaching in the following words:

In his human soul united to his divine person, the dead Christ went down to the realm of the dead. He opened heaven's gates for the just who had gone before him.14

Also in developing this anthropological understanding, we must include the imago dei15 and the significance of being a person in the image of the Persons of the Blessed Trinity, again from the time we are a zygote until death, and then in the continuity of being a body after resurrection.

Shewmon makes no apparent attempt to link his theories of integration to doctrine and Tradition or to any accepted philosophy.

His account leads to an oddity in his discussion of the notion that a person might consist of a “brain in a vat”. If this view is linked to his idea that the body could be considered to continue as a living person after the brain has died, then a person could be at the same time two persons – the isolated brain in a vat and the body left behind. There is something distinctly odd about a notion of integration that would allow for such a division which would contradict the essential unity of the human body. The possibility highlights the fact that Shewmon does not understand integration as implying the role of the soul in forming and informing the dynamic unity that is a human being.

I recall standing in an IVF clinic, a result of serving in a government role, and wondering about the precious content held within the tanks of liquid nitrogen. In the tanks there were literally hundreds of straws held in racks, each containing a human embryo, dried and frozen and held in a state of suspended animation. By the latter I mean that there was no growth and no biological activity of any kind. But as a matter of faith, I believed that each embryo instantiated a human soul and, because of that, each was the form and the reality of the adult he or she would become, if given the right environment in which he or she would be rehydrated and thawed and then transferred to a woman’s uterus. Each of those straws contained such an extraordinary reality. Each was just a cluster of cells, but at the same time so much more than just cells, because those clusters of cells were human lives. They already contained the form of that person. As a cluster of cells they were linked together as a single entity already pre-programmed to develop in a predictable fashion, given the right conditions.

At another time I chaired a government committee16 to develop ethical guidelines for the care of people in a post coma unresponsive state, (sometimes unfortunately referred to as a persistent vegetative state). It was brought home to me, by those caring for the patients I visited, that the unresponsiveness was just what we observed. What was happening within those individuals remained so much a mystery to us despite our brain scanning technologies. They had brain activity, but it was not connected to any observable expression of that activity. I also met some rare individuals who had survived several years in that state before recovering to a point that they could speak of their experiences.

I asked one young such man, (he had been over two years without showing any responsiveness), who came to the launch of the ethical guidelines, what he remembered of his experience. He said he recalled conversations being held about whether to continue nutrition and hydration delivered through a PEG (percutaneous endoscopic gastrostomy). He said that he was also aware of the love of his parents (his father, a general medical practitioner, and his mother, a nurse), and had confidence that they would protect him, as indeed that did.

There is, however, such a contrast between post-coma unresponsiveness which includes sleep-wake cycles, on the one hand, and, on the other, a person whose brain has completely died and the harsh reality of seeing the images of that patient’s contrast angiogram showing no blood supply to the brain. In the latter case one knows that on autopsy the brain would be found to be a liquid without structure or life, and that it is only technology that sustains a semblance of the dynamic unity possessed by both the frozen-dried embryo and the person in an unresponsive state. In fact, no such unity exists once there is complete absence of brain function because the systems that communicate between organs, the neural and endocrine systems, are missing a vital element. Circulation can be maintained, with assistance, but circulation without a brain is like a postal system, without mail. Circulation is the means of communication, it is not in itself communication. The dynamic unity that is a personal life has been lost. Shewmon’s insistence on circulation being a form of integration really misses the point that integration implies a dynamic intercommunicative unity. To be a unity in a meaningful sense the parts must be in actual communication with each other, not just be collocated with a system that could carry communications. The fact of the matter is that without the functions of the brain, the neural and endocrine systems have been profoundly interrupted. Circulation may be maintained, for a time, and thus the system for carrying communications, but the means of generating those communications is no longer present. There is thus no empirical evidence of the forming and informing that the doctrine refers to as the functions of the the unity that is the life of the person.

3. Assessing the Significance of Remaining Activities

A difficulty that we have always had in understanding death of the human body is that, in most instances, some living activities persist within the body after death. Some of these can be dismissed as parasitic, such as the bacteria within the gut, though they ordinarily have important functions there. I have had personal experience of the harm that occurs if those bacteria are destroyed by strong anti-biotics. Some activities seem not to be significant, such as hair and fingernail growth. We can even remove a living sperm from a dead man, long after his heart and circulation has ceased, and use it reproductively so that he can father a child posthumously.

It is true that, after loss of all function of the brain in a body maintained to some extent on life support, there is certainly more activity occurring within that body than would occur in a body in which circulation had ceased. The issue is whether this activity is sufficient to provide evidence that the dynamic, intercommunicative unity of the body is maintained in those activities or whether the activities occur in relative isolation and not as a functional or dynamic unity.

As I have indicated, part of the difficulty in relation to Alan Shewmon's assumptions about continuing functions in a body in which all function of the brain has ceased, and consequently the position he has adopted rejecting the brain criterion, is that he is operating in an environment in which the Mode of Being view is dominant. The Mode of Being view was described by the U.S. President's Council17 as the contemporary basis for accepting death by the brain criterion. The Mode of Being view requires interaction with the environment. The Council rejected an integration view of death by the brain criterion and, more importantly, in doing so it set criteria for diagnosing death by the brain criterion that included only irreversible loss of spontaneous breathing and irreversible loss of consciousness, not loss of all brain function. In a way this was a recognition that US medical practice had moved away from what remains the legal definition of death in the U.S.:

An individual who has sustained either (1) irreversible cessation of circulatory and respiratory functions, or (2) irreversible cessation of all functions of the entire brain, including the brain stem, is dead. A determination of death must be made in accordance with accepted medical standards.18

Unlike the U.S., the U.K. has actually changed its law to reflect what is now the U.S. Mode of Being view. In 1995, the U.K. adopted irreversible loss of brain-stem function as the legal definition of death,19 thus better reflecting U.K. medical practice that had moved away from testing for irreversible loss of all brain function to testing for loss of brain stem function only.

Establishing irreversible loss of spontaneous breathing and of consciousness, which result from loss of brain-stem function, is a much lesser standard. The latter is certainly not what John Paul II accepted when he explained that the neurological criteria for determining death “consists in establishing, according to clearly determined parameters commonly held by the international scientific community, the complete and irreversible cessation of all brain activity (in the cerebrum, cerebellum and brain stem).”

What is referred to in actual medical practice as “brain death” in the United States and in most English-speaking countries, is now not loss of all function of the brain at all. Loss of consciousness and loss of spontaneous breathing may mean only that there is substantial damage to the brain stem.

There has been a significant change in the diagnosis of death by the brain criterion since I first began in this area, over 30 years ago. At that time, the clinical tests for brain-stem function were used at the end of a process to determine that the assessed damage to the higher parts of brain, usually as a result of brain swelling after trauma, had extended down to include the brain stem. In other words, swelling of the brain, in the rigid container that is the skull, caused loss of blood supply and thus destroyed not only the upper and mid-brain but also the brain stem. The clinical tests for some brain stem functions were thus only confirmatory and not, on their own, determinative.

In August 2012, at the launch of my book, About Bioethics: Vol. III, Transplantation, Biobanks and the Human Body (Connor Court, Ballan 2012), the Vice Chancellor of Monash University, Professor Ed Byrne, a neurologist, supported this interpretation of the changes that had occurred since he and I worked together as fellow department heads at St. Vincent’s Hospital, Melbourne, in the 1980s. At that time, after having death diagnosed by the brain criterion, it was understood that this was not a stable state and heart function would cease within 24 hours. That was such a contrast to what is now described as “brain death”, with some pregnant women even surviving in that state long enough to give birth months later!

Unfortunately, the way in which the criteria are now applied, it is not necessary to have established that all functions of the brain have ceased. It is possible and in fact not uncommon, that the current criteria being applied in English-speaking countries permit the diagnosis of death, according to the Mode of Being view, on the basis of damage to the brain stem alone, which would result in irreversible loss of consciousness and irreversible loss of spontaneous breathing, but not always loss of all brain function.

Alan Shewmon has reported a case in which homoeostasis was maintained in a patient who had been diagnosed according to the criteria applying in the U.S. for diagnosing death. The Pontifical Academy of Sciences did not accept Shewmon’s claim in that respect,20 but it should be borne in mind that the panel was comprised mostly of Europeans and the widely accepted European practice is not the Mode of Being view, but loss of function of all parts of the brain.21 Homeostasis cannot be maintained in that state, which is partly why, thirty years ago, loss of circulation followed death by the brain criterion within 24 hours. The practices I have observed in Europe involve using ancillary testing to determine that there is no blood supply to the brain. That does establish with some certainty that there is loss of all brain function because warm brain tissue dies quite rapidly if deprived of oxygenated blood. Shewmon’s context, what he would understand is meant in practice is death determined by the brain criterion, is not what Pope John Paul II described as death by the neurological criteria. The latter clearly reflected a quite different practice from the current U.S. practice, the so-called Mode of Being view or what, in the law of the U.K., is now accepted as the death of the brain stem alone. We have the same problem in Australia and New Zealand with the leading authority, the Australia and New Zealand Intensive Care Society (ANZICS), describing the determination of death by the brain criterion as being diagnosable by the clinical tests for brain-stem function and at the same time admitting to continuing functions that are brain mediated functions.22

The ANZICS position is odd. On the one hand, the document states:

Brain death cannot be determined without evidence of sufficient intracranial pathology. Cases have been reported in which the brain-stem has been the primary site of injury and death of the brain-stem has occurred without death of the cerebral hemispheres (e.g. in patients with severe Guillain-Barré syndrome or isolated brain-stem injury). Thus brain death cannot be determined when the condition causing coma and loss of all brain-stem function has affected only the brain-stem, and there is still blood flow to the supratentorial part of the brain. Whole brain death is required for the legal determination of death in Australia and New Zealand. This contrasts with the United Kingdom where brain-stem death (even in the presence of cerebral blood flow) is the standard.23

On the other the document allows for the diagnosis on the basis of the clinical tests without ancillary testing to rule out middle and upper brain function, and it affirms that the following activities may continue in someone diagnosed by the clinical criteria (brain-stem) alone:

  • sweating, blushing, tachycardia;
  • normal blood pressure without the need for pharmacological support; and
  • absence of diabetes insipidus (DI) (preserved osmolar control mechanism).24

This is contradictory.

4. The View of the Church

Alan Shewmon criticizes me for asserting that his view is out of keeping with Church teaching, claiming that I assert that the Church “is committed to the view that total and irreversible loss of brain function is (a sure sign of) the death of human being.”

Those are not my words. If Shewmon were to look closely at each of the references to the Church and the Pope that I made in the article he critiques, he will see that I have referred to Pope John Paul II’s actual words in permitting, not doctrinally prescribing, the loss of all brain function criterion, and he will see that I have referred to other views within the Church, notably his own. Nowhere have I implied that all other views were excluded.

However, I have indicated that his treatment of “integration” is not based on the doctrine as proclaimed at Vienne and used by Pope John Paul II in his explanation of the permissibility of the adopting the loss of all brain function criterion. This is the major problem with Shewmon’s account of integration. His own critique of my view makes no attempt to relate his account of what integration is to the theological basis of the doctrine or to an established anthropology that would be consisted with the Tradition with respect to the unity of the soul and the body.

5. Other Matters

A large proportion of Shewmon’s critique is about the activities of the Pontifical Academy of Sciences and I do not, and have not, endorsed the ways in which he and his material were treated by the Academy. Further, I think it remiss of the Academy not to have acknowledged that there are different medical standards being applied in the definition of death and that what the Academy means by it, defined in terms of irreversible loss of all brain function, is by no means universal. That said, I think that is a difference in the US medical culture that contributed to the problems that Shewmon had with the Academy. Clearly what death by the brain criterion means in the US, the UK, and other parts of the English-speaking world, is something much less, as described by the US President’s Council in 2009 as the Mode of Being view, and identified by irreversible loss of consciousness and of spontaneous breathing only. I do not think it necessary to comment further on Shewmon’s complaints about the Academy as they do not seem particularly relevant to his criticisms of me or to my response to those criticisms.

Shewmon produces a number of other arguments against what he claims is my position. It does not seem necessary to go into them all because many are based on false claims about my position. They seem to be to do with his assertions that I claim that the brain is the master organ and that there is only one view permissible within the Church. As explained, I have not, and do not, make either claim.

Shewmon does, however, make a number of medical claims that are at odds with my understanding of the state of medical knowledge on these matters. First, the functioning of the hormone system is controlled by the hypothalamic-pituitary axis in the brain. So, for instance, if the hypothalamic pituitary axis were to cease functioning, as happens if all function of the brain were to cease, then other hormonal glands would cease to receive the triggers that cause them to release hormones. For instance, if there was loss of all brain function, the insulin-producing islets would cease to produce insulin and diabetes insipidus would ensue. This is seen in about 50% of patients diagnosed by the brain criterion in Australia relying on the clinical (brain-stem only) tests, indicating that the other patients retain some functions of the brain, the mid-brain especially, and do not meet the criterion of loss of all brain function. When I was first involved in this area in the 1980s, all patients who were diagnosed by the brain criterion had developed diabetes insipidus.

A failing of Shewmon’s critique is also not to provide adequate acknowledgement of the problem that most English-speaking countries having departed from the loss of all brain function criterion, at least in practice, if not in law, by accepting the clinical (brain-stem) tests as sufficient to establish death without ancillary testing.

It needs to be said that Shewmon’s position is very different from Robert Spaemann’s.25 The latter’s view includes some claims about the capacities of those who have suffered loss of all brain function that cannot be substantiated and go far beyond Shewmon’s claims. After suffering irreversible loss of all brain function, no-one will be reaching out to touch their attendant nurse!

The teaching of Pope John Paul II that permits diagnosis of death by the brain criterion is doctrinally sound and well-founded within our tradition. The medical facts of the matter, in relation to what counts as evidence that the parts of what remains of the body are no longer the dynamically interrelated unity that is the personal self, are an empirical matter and open to developments in science. However, I can see no reason, on the basis of Shewmon’s claims, to reconsider my view that he is mistaken philosophically and theologically, and that his challenge on medical grounds is not sustainable. However, at the same time the Mode of Being view adopted in many English-speaking countries, and the context for Shewmon’s commentary in the issue, is not acceptable. As a matter of pastoral advice, it is important for a family to ask for proof of death in the form of an image showing lack of blood supply to the brain. Catholic hospitals should also require that there be evidence, of that kind, that all function of the brain has ceased.