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Wednesday, October 23, 2019

What is death?

The following is an excerpt from Louis Pojman's book Life and Death (1992), pp 158-164. It discusses criteria for death as well as organ transplantation. I strongly disagree with Pojman on these matters. However, he gives a decent enough summary of the main categories for death and related issues that I'll quote it here. In addition, Pojman's argument (which was made in 1992) doesn't seem substantially different from how progressive ethicists argue today. I'll have to interact with Pojman at a later time.

What Is Death?

Four definitions of death appear in the literature: (1) the departure the soul from the body; (2) the irreversible of the flow of vital fluids or the irreversible cessation of cardiovascular pulmonary function; (3) whole brain death; and (4) neocortical brain death.

The Loss of Soul. The first major philosopher to hold that death occurred with the departure of the soul was Plato, but the view is found in the Orthodox Jewish and Christian traditions and in the writings of René Descartes (1596—1650), who believed that the soul resided in the pineal gland and left the body at death. The sign of the departure was the cessation of breathing. The Orthodox Jews say that a person is dead only when the last breath is drawn.3 Note that the Hebrew word for spirit, Ruach, is the same word used for breath, and the Greek word pneuma has the same double meaning.

There are problems with this view. First, it is difficult to know what the soul is, let alone whether we are endowed with one (or more). Second, neurologic science can explain much of human behavior by an appeal to brain functioning, so that the notion of a separate spiritual entity seems irrelevant. Third, if a soul is in usa nd if it only leaves us after we have breathed our last, medical technology can keep the soul in the body for scores of years after the brain has ceased to function and, as far as we can tell, all consciousness has long disappeared. Unless we are really convinced that God has revealed this doctrine to us, we should dismiss it as unsupported by the best evidence available.

The Cardiopulmonary View. When the heart and lungs stop functioning, the person is dead. This has been the traditional medical definition. Black's Law Dictionary puts it this way: "The cessation of life: the ceasing to exist; defined by physicians as a total stoppage of the circulation of the blood, and a cessation of the animal and vital functions consequent thereupon, such as respiration, pulsation, etc." In Thomas v. Anderson a California District Court in 1950 quoted Black's and added, "Death occurs precisely when life ceases and does not occur until the heart stops beating and respiration ends. Death is not a continuous event and is an event that takes place at a precise time."4

This standard definition is problematic in that it goes against the intuitions of many of us that irreversibly comatose patients like Karen Ann Quinlan or Nancy Cruzon are not alive at all. Bodily functioning alone does not constitute human life. We need to be sentient and self-conscious.

The Whole Brain View. As Roland Puccetti puts it, Where the brain goes, there the person goes.5 In the same year that Bruce Tucker had his heart and kidneys removed, the Ad Hoc Committee of the Harvard Medical School under the chairmanship of Dr. Henry K. Beecher met to decide on criteria for declaring a person dead. The study was a response to the growing confusion over the uses of biomedical technology in being able to keep physical life going for an indefinite period of time after consciousness has been irretrievably lost. It also was a response to the desire to obtain organs from "donors" who were permanently comatose but whose organs were undamaged - because of the ability of technology to keep the vital fluids flowing.

The Committee came up with four criteria that together would enable the examiner to pronounce a person dead: (1) unreceptivity and unresponsivity (i.e., no awareness of externally applied stimuli); (2) no movement or breathing without the use of artificial mechanisms; (3) no reflexes; the pupil is fixed and dilated and will not respond to bright lights; (4) a flat electroencephalogram, which indicates that there is no cerebral activity. The test must be repeated at least 24 hours later to rule out rare false-positives (such as those caused by drugs or hypothermia - the body's having a temperature of less than 90° F).

The Harvard Committee's criteria have been widely accepted as a safe set, allowing medical practitioners to detach patients from artificial respirators and to transfer organs to needy recipients. Of thousands of patients tested no one has regained consciousness who has met the criteria.

But critics have objected that the Harvard criteria are too conservative. By its norms patients who are permanently comatose or in persistent vegetative states, like Karen Ann Quinlan and Nancy Cruzon, would be considered alive, since their lower brainstems continued to function. Indeed, people have been recorded as living as long as 37 years in this unconscious state. Since they are alive and can be fed intravenously, or via gastric feeding tubes, we have an obligation to continue to maintain them. The worry is that hospitals and nursing homes could turn into mausoleums for the comatose. So a fourth view of death has arisen.

Neocortical Brain Death. What is vital to human existence? Henry Beecher, head of the Harvard Ad Hoc Committee, says "consciousness." Henry Veatch, a prominent medical ethicist, says it is our capacity for social interaction, involving the power of thought, speech, and consciousness. These higher functions are located in the neocortex of the cerebrum or upper brain, so that when a sufficient part of this section of our brain is destroyed, the patient is dead. As Tristram Engelhardt Jr. says, "If the cerebrum is dead, the person is dead."6 An electroencephalogram can determine when the cerebrum has ceased to function.

Beecher, Veatch, and Engelhardt see human death as the loss of what is significant for human life. Veatch defines death this way: "Death means a complete change in the status of a living entity characterized by the irreversible loss of those characters that are essentially significant to it."7

Where does the truth lie? To understand what is going on in this debate we should note the relevant physiologic and neurophysiologic aspects. The brain has three basic anatomic parts (Fig. 11-1): (1) the cerebrum, with its outer layer, the cortex; (2) the cerebellum; and (3) the brainstem, including the midbrain, pons, and medulla oblongata. While the cerebrum is the locus of thought, memory and feelings, consciousness itself remains a mystery. Many believe it to result from complex interrelations between the brainstem and cortex. The brain is kept alive by blood carrying oxygen. If it is deprived of oxygen for more than a few minutes, it sustains permanent damage. After 4 or 5 minutes of deprivation, it usually dies.


(Figure 11-1)

Respiration, on the other hand, is controlled in the medulla of the brainstem (Fig. 11-2). When the medulla is destroyed, the body is unable to breathe and normally dies, unless placed on an artificial respirator. When the respiratory system is destroyed, the heart is deprived of vital oxygen and dies. Unlike the respiratory system, the heart can pump blood without instructions from the brain, though the brain may control the heart rate. When the heart is destroyed, it cannot pump oxygen to the brain, so the brain dies.


(Figure 11-2)

We see the possible combinations:

  1. Respiratory system destroyed but artificial respirator keeping heart and brain orygenated.
  2. Heart destroyed but artificial heart pumping blood to brain and lungs.
  3. Cerebrum destroyed but heart and lungs still functioning (the persistent vegetative state). Neocortical death.
  4. The brainstem and cerebrum destroyed but the heart still beating and the lungs still maintained by an artificial respirator. Whole brain death.
  5. The brainstem, cerebrum, and heart all destroyed.

Biomedical technology has allowed these possibilities to arise. We are looking at the issue as a problem, but, in a sense, the problem is simply the downside of an enormous blessing. We should be grateful for such life-saving mechanisms. Without the ventilator many living people would be dead. Because of the ventilator we can keep organs fresh to transplant them to needy recipients.

Still the new wonders have brought with them new responsibilities and conceptual confusion about the meaning and nature of death.

The move to alter our definition of death is well motivated. First, we desire to alleviate the agony and financial burdens of relatives waiting for their comatose loved ones to die. How long must the relatives maintain irreversibly unconscious patients? Karen Ann Quinlan was kept alive in a nursing home for 10 years, and others have been maintained even longer. If we can agree to a view of death that includes the cessation of consciousness or neocortical functioning, we can mitigate the emotional suffering and financial hardship of loved ones.

Second, a redefinition of death would enable us to transplant organs from biologically viable humans to needy recipients. By keeping the body alive but pronouncing the person dead, we can justifiably transfer fresh organs to waiting patients.

There is a growing tendency to accept this logic. How absurd to care for bodies without minds. Keeping Karen Ann Quinlan in a nursing home for 10 years seems irrational. When the cerebral cortex dies, so does the human being. All that is valuable comes to an end with the end of conscious life. To be permanently comatose is to be dead.

However, this argument has a problem that must be addressed before its conclusion is accepted. The questionable move involves substituting a value for a fact or deriving a factual definition from our moral values. Veatch is guilty of this when he defines life as containing "those characteristics that are essentially significant to it" and death as the irreversible loss of those characteristics. The key phrase is "essentially significant," that is, valuable.

This redefinition muddies the waters. A comatose human whose lower brainstem is still functioning, whose heart is beating, and whose respiratory system is intact is still a living organism. Thus, something like the second view of death is correct. Death is an event, not a process, in which the biologic organism ceases to function. The vital fluids cease to flow and the heart and lungs cease forever.

David Mayo and Daniei Winkler make this point with regard to the dying process by distinguishing four possible states of the human organism.8 Beginning with death proper the stages are:

Stage 4. All principal life systems of the organism (cardiovascular, central nervous, and pulmonary) irreversibly cease functioning. The organism as a whole permanently ceases to function. This is death proper.

Stage 3. The patient is irreversibly comatose because the entire brain ceases functioning, but cardiovascular and pulmonary functions continue because they are maintained by artificial life support systems.

Stage 2. The patient is irreversibly comatose because the cerebral cortex has ceased functioning but the brainstem is still active, so that the cardiovascular and pulmonary functions continue.

Stage 1. The dying patient is conscious and in pain and desires to be in Stage 4.

Here Mayo and Wikler separate the biologic from the valuational or moral dimension. That persons in Stages 1 to 3 are alive is a biologic fact. But it is a value question whether we should keep them alive. Only Stage 4 constitutes death, properly understood, but our respect for the patient's autonomy should place the burden of proof on those who would paternalistically intervene in preventing the patient from going from Stage 1 to Stage 4. In Stage 2, the case of irreversible coma, we are absolved of any duty to preserve life since it has lost what is valuable about humanity. The same goes for Stage 3. The patient should be detached from the artificial maintenance and left to die.

So what should we do about the tragic blessing of biomedical technology with its ability to keep the organism, but not the mind, alive indefinitely? If Mayo and Wikler are right, we should give up our notion of the sanctity of biologic life, and recognize that some lives are not worth living, including life as an organism in a persistent vegetative state. Although the irreversibly comatose being is biologically alive, it is no longer a life possessing any quality. If we see that personhood involves being self-conscious, we may say in these cases that although the body is alive, the person is dead. Not only should the body be detached from expensive life-saving machines, but its organs should be removed for use on the living. Organs are a precious medical resource that can be used to enable people to live longer and better.

Indeed, you might conclude that this reasoning entails a presumption of organ removal in irreversibly comatose patients, to be overridden only by the expressed wishes of the person when he or she was alive. That is, given suitable public education, we should realize that the organs of the irretrievably comatose or dead should be used to help the living.

Just as the United States Supreme Court has ruled that a dying person can give advance notice that should he or she become irreversibly comatose, all life support systems should be removed, so likewise our living wills should have provisions in them directing that our organs be removed for transplantation while we are in such a state. In this case the immediate cause of death should be recorded as the donation of vital organs rather than removal of life support. This should be the next step in the attempt to make moral use of our technologic wonders. Eventually, a presumption in favor of transplanting organs from brain dead and neocortical dead patients would be recognized.

The response of the definitional reformers to all this is that the term death already has value connotations with the public, so that in including the permanent loss of consciousness in the definition of death, we are preserving what is practically valuable about the concept.

This response needs careful consideration. It may, in the end, be the right way to go. Nonetheless, clarity of thought inclines us to separate the biologic fact of death from the valuational and admit that a body with a dead cerebrum but a living brainstem is still biologically alive. Perhaps we need two locutions, "biologic death" and "person death," to preserve the integrity of meaning. So long as we see the issue clearly, the names don't matter.

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