What is Death?( 2)

Did Walt Whitman and his poem, in my last post, explain death to your satisfaction? No? Maybe Ken Kipnis, who is a philosopher/bioethicist, can explain it better in the following article he wrote for The Philosophers' Magazine. My thanks to Ken and his publishers for allowing me to post the entire article here. ..Maurice.

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When Are You dead?
by
Kenneth Kipnis
Department of Philosophy
University of Hawaii at Manoa
kkipnis@hawaii.edu


It is, alas, one of the most familiar things in the world. Alive one
minute, dead the next. But what exactly happened?

On the surface, there has been a dramatic change in social standing: a
living human being has become a corpse. The former might have enjoyed
rights to health care and legal protections against an array of
wrongs. Death makes an end to these, and to marriage, citizenship, and
even legal personhood. It is perhaps the most complete and final
alteration of status known to law. We can now cut open the body out of
intelligent curiosity, burn or bury it; hand it over to medical
students for dissection; gather up personal property and distribute it
to others, all of which would be grave wrongs if ever done to the
living. It is no wonder that premature burials and twitching body bags
are the stuff of horror stories. It is no mystery why communities take
exquisite care to avoid mistakes that are beyond embarrassing. Because
so much hangs on the official pronouncement, only the most
knowledgeable are authorized to certify that death has occurred. But
what exactly is the warrant for their judgment?

Conversations about the definition of death are commonly plagued by
ambiguity in the level of analysis. Beyond the social account set out
just above, it is useful to distinguish among four other levels:
biological, physiological, clinical and legal. The stories we tell
about the nature of death have to have at least that many chapters.

We begin, at the deepest biological level, with the nature of animal
life. Herewith a thumbnail history of biological metaphors for the
living body. If, as an animal, our essential Aristotelian nature
involves locomotion, then we cease to exist (as animal-natured beings)
when our capacity for locomotion ends. But if, as Harvey discovered,
we are pulsating, vascularized circulations of life-giving blood, then
we cease to exist as living creatures when the vital flow stops. And,
finally, if we are wet computers, neurologically connected to input
and output peripherals (as many have come to believe) then we cease to
exist just when our central processing units fail, permanently and
completely.

Within each of these three conceptions, the next task is to draw upon
physiology (the second level) to define biological death. Breathing
is a most subtle locomotion, perhaps the most essential and the last
to disappear. We still speak of people "expiring." So understood,
death occurs when respiration ceases. Later on, for theorists
following Harvey's discovery, a person could be said to have died when
the essential cardiac pump stopped beating. No pump, no blood flow,
no life. Finally, for most contemporary theorists, death occurs
decisively when the brain (or some substantial portion of it - the
jury is still out) dies, even if the heart continues to function. The
phone can ring but nobody is home.

The third level is clinical. In practice, how should health care
professionals determine that the critical physiological state is
present. One very old test involved a mirror held near the nostrils.
The patient was alive if the glass fogged, dead if it remained clear.
Following Harvey, the stethoscope allowed physicians to ascertain the
absence of heartbeat, the cessation of circulation and, therefore,
death. But the cardiac criterion became problematic perhaps fifty
years ago as advancements in resuscitation, life support and surgery
allowed patients to survive the stilling of their hearts. People joked
about having been dead for twenty minutes, reveling in the patent
contradiction. While no dramatic changes in social standing were
occurring, it was time to revise the cardiac conception of death. The
transition to death by neurological criteria is still evolving.

The process began shortly after the first heart transplants, with the
1968 publication in JAMA of the Report of the Ad Hoc Committee of the
Harvard Medical School to Examine the Definition of Brain Death. The
Ad Hoc Committee urged that death be understood as the irreversible
loss of function of the whole brain, including the brain stem. This
medical conception was quickly and widely adapted as a legal criterion
in the United States. By 1981 the American Bar and Medical
Associations had endorsed the Uniform Determination of Death Act which
held that:

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.

Notice how the new standard is piggy-backed onto the Aristotelian and
cardiac conceptions of death. The added definition effectively
eliminates the inherent legal risks associated with harvesting
transplantable hearts.

Notice also how the language of the Act sets out a procedural
criterion for brain death as well as a substantive one. Though
irreversible cessation of all brain functions is essential, the
determination of brain death requires physician compliance with
"accepted medical standards." As doctors became comfortable with the
new definition, gold-standard confirmation by brain-wave and
blood-flow analysis fell out of use. Along with some other clinical
observations (absence of a gag reflex, unresponsiveness of the pupils
to light, etc.), the most dramatic assessment tool has been the apnea
test. The unconscious, brain-injured patient is removed from the
ventilator for several minutes. If breathing does not begin as the
seconds pass -- as carbon dioxide builds up in the blood stream --
doctors can infer the destruction of those brain stem regions
governing unconscious respiration. While the law is clear enough about
physiology, it hands off the clinical practicalities to physicians.

But islands of neurological activity can persist even when brain death
is established according to the accepted tests. The regulation of
temperature is one example. When certain neurological structures are
disabled, body temperature destabilizes. Clinicians must then use
thermal blankets and sensors to heat and cool patients. Despite the
legal requirement that there be "irreversible cessation of all
functions of the entire brain . . ." death is often pronounced when
some brain functions are evidently unimpaired. In these situations, do
the physiological or the medical standards have priority? If some
activity persists, exactly how much of the brain has to be
irreversibly lacking in function before death is present? And how
certain must clinicians be that this condition is met?

Michael Green and Dan Wikler offered some useful analysis in their
1980 paper, "Brain Death and Personal Identity." They begin with a
rough distinction between the lower brain (including the brain stem)
and what we will term the higher brain (including the cerebral
hemispheres). The lower brain manages many autonomic biological
functions: movement of food through the intestines, breathing while
asleep, temperature regulation etc. The higher brain is where
personhood is lodged: memories, skills, emotional traces, knowledge,
etc. While many have thought that a higher-brain criterion is superior
to a whole-brain criterion, in 1968 EEGs could not reliably determine
whether weak electrical impulses were emerging from the brain stem or
elsewhere. As a practical matter, it made sense to include destruction
of the brain stem in the definition of death. It is always safer to
err by treating a corpse as a living person rather than risk treating
a living person as a corpse.

Green and Wikler challenged several standard justifications for the
neurological criterion. Some had defended it by pointing out that
those declared "brain dead" would shortly be dead by cardiac criteria.
But even if some present condition were invariably followed by cardiac
death, that would not entail that one were dead already. Some had
defended it by noting that those declared "brain dead" could no longer
have lives that were subjectively valuable. But even if one no longer
cared about being alive (or anything else), that would not entail
that one had died (though it might mean that one could no longer be
harmed by dying).

Drawing on John Perry's work in metaphysics, Green and Wikler argued
that, despite errors in the standard justifications, the death of the
higher brain really is death. Their reasoning can perhaps be
succinctly captured in two thought experiments.

1. The Getaway: Pursued by the police for heinous crimes, Moriarty
engineers the ultimate escape. Using science fiction technologies, he
arranges to have his higher brain transplanted into the skull of
Alfred, a kidnapped dustman. Recovering from the surgery, he
eventually opens what used to be Alfred's eyes and continues writing
his autobiography using what used to be Alfred's hand.

It would appear that the police should now be looking for a man with
Alfred's body: i.e., Moriarty. The philosophical implication: personal
identity follows the higher brain.

2. The Mishap: In the operating room, Moriarty's higher brain has been
removed and is being carried in a basin to what had been Alfred's
body, with its now vacant cranium. Suddenly the basin-carrier trips,
the grey mass launches into the air and breaks into moist fragments as
it plops onto the floor.

Though what used to be Moriarty's body is still robust, Moriarty has
ceased to exist. The philosophical implication: the death of the
higher brain marks the death of the person.

Considerations like these, and the scientific findings that make them
relevant, are persuasive in showing that higher-brain death marks the
end of personal life.

But what about those islands of neurological activity in patients who
are brain dead according to the tests in current usage? Alas, there is
no reliable, quick, cheap and simple way to rule out the presence of
potentially functional regions; no neurological analog to the mirror
and stethoscope. And even if we could locate and identify the tiniest
active areas, we are far from being able to decide what kinds and
amounts of neurological activity are compatible with a determination
of death.

Though neurology has made enormous progress in recent years, we are
still importantly in the dark. Our legal systems and medical
professions are muddling through the most consequential judgments we
will ever face. But while clinicians are probably doing well enough.
there is a troubling concern that we have left behind the old
paradigms without fully appreciating the life-and-death issues arising
out of the new one.

First published in The Philosophers' Magazine, Issue 27, 3rd Quarter
2004. Reprinted with the permission of the author and the publisher.


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RECOMMENDED READINGS

McMahan, Jeff. The Ethics of Killing. Oxford University Press: New
York, 2002. Chapter 5, pp. 423-503.

Green, Michael, and Daniel Wikler. 1980. "Brain death and personal
identity." Philosophy and Public Affairs 9:105-133.

John Perry, ed. Personal Identity (Berkely and Los Angeles:
University of California Press: 1975).

Stuart J. Youngner, Robert M. Arnold, Renie Schapiro, eds. Definition
of Death: Contemporary Controversies, (Baltimore: Johns Hopkins
University Press: 1999).
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