Although established in the law and current practice, the determination of death according to neurological criteria continues to be controversial. Some scholars have advocated return to the traditional circulatory and respiratory criteria for determining death because individuals diagnosed as ‘brain dead’ display an extensive range of integrated biological functioning with the aid of mechanical ventilation. Others have attempted to refute this stance by appealing to the analogy between decapitation and brain death. Since a decapitated animal is obviously dead, and ‘brain death’ represents physiological decapitation, brain dead individuals must be dead. In this article we refute this ‘decapitation gambit.’ We argue that decapitated animals are not necessarily dead, and that, moreover, the analogy between decapitation and the clinical syndrome of brain death is flawed.
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The definition of death and criteria for determining it are deeply contested issues, despite being of central significance in the practice and ethics of organ donation. The established position on the transplantation of vital organs affirms the following three propositions: (1) donors must be dead before vital organs are procured (the ‘dead donor rule’); (2) death is defined as the cessation of the functioning of the organism as a whole; and (3) individuals who satisfy the clinical criteria for ‘brain death’ are dead on the basis of this biological definition of death. In recent years, some scholars have challenged neurological criteria for determining death and have advocated return to sole reliance on traditional circulatory and respiratory criteria.1 2 They have argued that the concept of brain death is fundamentally flawed because patients diagnosed with this condition have the capability to maintain an extensive range of integrative functioning of the organism as a whole. Accordingly, those who satisfy the clinical criteria for brain death cannot coherently be considered dead on the basis of the established biological definition of death. If these scholars are correct, then an ethical sea change is required. We will need to choose between: (1) finding an alternative account for why those diagnosed as ‘brain dead’ are dead; (2) changing our current practices of vital organ transplantation with the aim of making them genuinely consistent with the dead donor rule; or, (3) developing a sound ethical account for current practices that justifies vital organ donation from still-living patients.2 3
The decapitation gambit
Critics of a return to relying solely on traditional circulatory and respiratory criteria for determining death have lodged what they regard as a decisive refutation: namely, that this position implies that a decapitated human being or other type of animal would be alive so long as it maintains circulatory and respiratory functioning.4 5 But this implication, the critics allege, is absurd. John Lizza has recently deployed this counter-argument, with the conclusion that sole reliance on circulatory and respiratory criteria for determining death must be rejected.5 6 He declares that ‘if anything entails one's death, decapitation certainly does, despite whatever artificial support might be given to sustain one's decapitated body as an integrated organism. Thus, if we are willing to accept decapitation as death, we should also be willing to accept physiological decapitation (total brain failure) as death.’5
When unpacked logically, this ‘decapitation gambit’ consists of two closely related arguments, which can be stated formally as follows.
Decapitation is an infallible sign and sufficient condition of death.
It is possible for a decapitated animal to maintain circulatory and respiratory functioning, either spontaneously for a short period of time or with mechanical assistance.
The circulatory-respiratory standard for determining death identifies the presence or irreversible absence of circulation and respiration as determining life and death.
It follows that the circulatory and respiratory standard must be false as a necessary and sufficient condition for determining death, because premises 1 and 2 entail that an animal dead by virtue of decapitation can maintain circulation and respiration.
Brain death constitutes physiological decapitation.
Decapitation is an infallible sign and sufficient condition of death.
Hence, individuals diagnosed as brain dead are necessarily dead.
Common and central to both of these arguments is the first premise in argument one and the second premise in argument two. Is decapitation an infallible sign of death? As the quote from Lizza suggests, it may seem perfectly obvious that decapitation constitutes death and thus without need for any explanatory rationale. However, several rationales might be provided to support this proposition. First, it is self-evident. Second, everyone agrees that a decapitated animal is dead. Third, it has been universally adopted by authoritative commentators within Orthodox Judaism as an infallible sign of death. Fourth, in view of the role of the brain in integrating the functioning of the organism as a whole, a decapitated animal without a brain is necessarily dead. Finally, the permanent absence of consciousness signifies death of the human being, and a decapitated human body lacks the organ responsible for consciousness.
We contend that the first four rationales are either logically or empirically deficient and thus fail to establish that a decapitated animal is necessarily dead. The fifth rationale does not count as a refutation for the position that advocates sole reliance on circulatory and respiratory criteria for determining death. After demonstrating that a decapitated organism can be alive according to a biological conception of death, we challenge the thesis that brain death constitutes physiological decapitation.
The crucial problem with the decapitation gambit is that it is doubly question-begging. It begs the question in arguments one and two by assuming that decapitation is necessarily death. It begs the question in argument two by assuming that brain death is physiological decapitation. We demonstrate the falsehood of both these assumptions sequentially.
Does decapitation necessarily constitute death?
Is it self-evident that decapitation signifies death? One reason why it may seem self-evident, or at least obvious, is that decapitation is a method of causing death in the context of human execution and animal slaughter, after which the victim rapidly progresses to an inanimate corpse. But is the decapitated animal invariably dead at the moment when decapitation occurs? It is necessary to answer this question in order to avoid conflating a diagnosis with a prognosis of death—a conflation which has been common in the literature on the definition of death. To be on a trajectory of no return with death as the inevitable and imminent outcome is not the same as being dead. Assuming a biological definition of death, if integrated functioning of the organism as a whole can be maintained following decapitation, even for only a few moments, the organism may be imminently dying but is not yet dead. Decapitation normally sets in motion a process of disintegration of the organism as a whole. All biological functions integrated by the brain necessarily cease. It doesn't follow that the organism as a whole has become entirely dis-integrated at the moment of decapitation. We will take up below the issue of whether observed activity of the decapitated animal represents mere reflex or other biological activity of isolated parts of the organism and not the integrated functioning of the organism as a whole.
Think of the proverbial farmyard scene of a chicken with its head cut-off running around before collapsing. Is this a dead chicken on the move? This case challenges the claim of self-evidence as well as the proposition that everyone agrees that a decapitated animal is dead. It seems counter-intuitive to declare that the moving chicken is already dead, rather than dying and soon to be dead. Likewise, it seems natural to describe the chicken as dropping dead when it collapses. It is important, however, to recognise that such intuitions may be mistaken. What appear to be signs of continued life in the decapitated animal might only reflect biological activity of particular disconnected organs, not the integrative functioning of the organism as a whole. Although possible, this conclusion does not seem compelling to us. While it moves aimlessly, the chicken's ability to run and to flap its wings suggests integrated activity of the headless body. Although the brain has been severed from the body, the spinal cord remains intact and provides the neural input necessary to drive the integrated behaviour of running. Whether this degree of integration is sufficient to conclude that the chicken continues to manifest the ‘integrated function of the organism as a whole’ may be debatable; however, the question of whether the chicken is alive or dead turns upon a judgement about the degree of this integration, not upon the mere fact that the chicken is decapitated.
Within Orthodox Judaism, decapitation has been regarded as a certain sign of death.7 Some scholars within this tradition have invoked the analogy between decapitation and brain death, with the latter seen as physiological decapitation. Since the decapitated animal is dead, brain death constitutes death of the human being. Yet other Orthodox scholars have contested the brain death diagnosis as a sign of death because respiration continues (with the aid of mechanical ventilation).8 In the context of this debate, two Israeli investigators conducted an experiment involving a decapitated pregnant sheep intended to validate decisively a neurological standard for determining death.9 This experiment helps to shed light on the force of the decapitation gambit.
Perhaps the most striking challenge to accepting ‘brain death’ as death of the organism as a whole is the known capability of pregnant women diagnosed with this condition to gestate a viable fetus for a considerable period of time, followed by successful birth of a living infant.10 11 How can a dead body possible accomplish this feat? The Israeli experiment was designed to prove that this is possible.
A pregnant near-term sheep was anaesthetised and connected by intubation to a respirator. Dissection of the head exposed the carotid arteries, which were tied and cannulated. The sheep's head was fully cut-off and the endotracheal tube placed in the tracheal opening. Pharmacological measures were introduced to maintain blood pressure and heart rate. Thirty minutes after decapitation, a healthy lamb was delivered by caesarian section.9
The investigators drew the following conclusion from their experiment:
Our experiment has proved that a decapitated animal in an intensive care set-up is capable of maintaining normal circulation and a normally beating heart. Moreover, we have proven that a decapitated animal can serve as an incubator for her fetus, and that a normal newborn can be delivered despite the demise of its mother, if appropriate modern measures are taken. There is no doubt that a completely decapitated animal is a dead animal; nonetheless, all vital organs, including a fetus, can function normally in such a situation.
Logically, the investigators were able to reach this conclusion only by virtue of assuming the premise that ‘There is no doubt that a completely decapitated animal is a dead animal’. They stated furthermore that ‘A decapitated animal is by all logical, theological and philosophical criteria a situation of clear organismal death’. Yet they supplied nothing beyond these question-begging assertions to back up the proposition that a decapitated animal is necessarily dead.
We contend that this experiment proves the very opposite of what was intended. The fact that the investigators were able to maintain circulation and respiration in a decapitated sheep, along with continued gestation of the fetal lamb for 30 min, indicates that vital functioning of the organism as a whole can be preserved despite decapitation, with the aid of mechanical ventilation and pharmacological intervention. For those who believe that pregnant brain dead women who can gestate a fetus in the intensive care setting must be alive, this experiment provides no evidence to the contrary. Instead, it demonstrates that decapitation is not incompatible with life.
As discussed above, a decapitated animal which maintains temporary heart beating or is able to briefly run around presents an ambiguous situation; based on a biological conception of death, some might consider the animal alive, others as dead. This is not the case for the sheep experiment, in which the decapitated animal clearly showed continued signs of homeostatic functioning reflecting integration of the organism as a whole. Based on a biological conception of death, there is no ambiguity here: the sheep remained alive during the experiment.
Finally, appeal to decapitation as death on account of permanent loss of consciousness cannot refute sole reliance on circulatory and respiratory criteria for determining death. The latter position adopts a biological definition of death; the former defines death with respect to a conception of personhood or what is considered essential philosophically to human life. There are reasons for and against these conceptually distinctive definitions of death, but the decapitation gambit and the analogy between brain death and decapitation are not decisive considerations in favour of a higher brain standard. As we have argued, decapitation does not necessarily signify death, understood as the cessation of functioning of the organism as a whole. Only if it did, would the decapitation gambit refute a biological conception of death that appeals solely to circulatory and respiratory criteria for determining death.
The decapitation gambit fails. Setting aside any preconceptions about whether decapitation constitutes death, the sheep experiment proves that a decapitated animal can continue to live with the aid of technological intervention. Moreover, Shewmon has thoroughly documented that brain dead patients sustained by mechanical ventilation remain biologically alive, as reflected in the wide range of integrative functioning not mediated by the brain that at least some of these patients display.12 13 These functions include circulation, respiration, digestion and metabolism, excretion of wastes, temperature control, fighting infection, wound healing, growth and sexual maturation in the case of children, and gestation of a viable fetus for up to 3 months in the case of pregnant women. As the brain is not necessary to make possible these integrative functions of the organism as a whole, continued living is not incompatible with physiological decapitation.
Is ‘brain death’ physiological decapitation?
The decapitation gambit suffers from an additional fatal flaw. Not only does it erroneously assume that decapitated animals are dead, it also begs the question regarding the characterisation of brain death as physiological decapitation. How good, in fact, is the analogy between decapitation and brain death? Obviously, no brain functions are possible in the decapitated animal. This would also be true if the accurate clinical diagnosis of irreversible apnoeic coma, known as brain death, reflects total brain failure. But whether this is true is an empirical issue. Multiple studies have shown that, in fact, most patients diagnosed as brain dead continue to manifest some brain functions, most commonly the regulated secretion of the hormone vasopressin, which is critical to maintaining the body's balance of fluid and salt.14 Not only is this hormonal regulation a brain function, it represents an integrative functioning of the organism as a whole. Furthermore, a recent neuropathological study of 41 patients who fulfilled the clinical criteria of brain death found that only about two-thirds of the patients showed evidence of moderate to severe neuronal ischaemia in the cortex, and less than half had this finding in the midbrain and brainstem.15 In short, in most brain dead patients the entire brain has not ceased functioning, and therefore they are not physiologically decapitated.
The clinical diagnosis of brain death does not coincide with the cessation of functioning of the human body as a whole or even the entire cessation of brain functioning. Whether individuals with this diagnosis are dead in some other meaningful sense will continue to be contested.
The opinions expressed are the views of the author and do not necessarily reflect the policy of the National Institutes of Health, the Public Health Service, or the US Department of Health and Human Services.
Funding This research was supported in part by the Intramural Research Program of the Clinical Center, NIH.
Competing interests None.
Provenance and peer review Not commissioned; externally peer reviewed.
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