According to the whole-brain standard,
human death is the
irreversible cessation of functioning of the entire brain, including
the brainstem
. This standard is generally associated with an
organismic definition of death (as explained below). Unlike the older
cardiopulmonary standard, the whole-brain standard assigns
significance to the difference between
assisted
and
unassisted
respiration. A mechanical respirator can enable
breathing, and thereby circulation, in a “brain-dead”
patient—a patient whose entire brain is irreversibly
nonfunctional. But such a patient necessarily lacks the capacity for
unassisted
respiration. On the old view, such a patient
counted as alive so long as respiration of any sort (assisted or
unassisted) occurred. But on the whole-brain account, such a patient
is dead. The present approach also maintains that someone in a
permanent (irreversible) vegetative state is alive because a
functioning brainstem enables
spontaneous
respiration and
circulation as well as certain primitive
reflexes.
[
1
]
Before turning to arguments for and against the whole-brain standard,
it may be helpful to review some basic facts about the human brain,
“whole-brain death” (total brain failure), and other
states of permanent (irreversible) unconsciousness. (The most
important terms for our purposes appear in italics.) We may think of
the brain as comprising two major portions: (1) the “
higher
brain
,” consisting of both the
cerebrum
, the
primary vehicle of conscious awareness, and the cerebellum, which is
involved in the coordination and control of voluntary muscle
movements; and (2) the “
lower brain
” or
brainstem
. The brainstem includes the
medulla
, which
controls spontaneous respiration,
the reticular activating
system
, a sort of on/off switch that enables consciousness
without affecting its contents (the latter job belonging to the
cerebrum), as well as the midbrain and pons.
With these basic concepts in view, it may be easier to contrast
various states of permanent unconsciousness. (For a helpful overview,
see Cranford 1995.)
“Whole-brain death”
or
total brain failure
involves the destruction of the entire
brain, both the higher brain and the brainstem. By contrast, in a
permanent
(
irreversible
)
vegetative state
(PVS), while the higher brain is extensively damaged, causing
irretrievable loss of consciousness, the brainstem is largely intact.
Thus, as noted earlier, a patient in a PVS is alive according to the
whole-brain standard. Retaining brainstem functions, PVS patients
exhibit some or all of the following: unassisted respiration and
heartbeat; wake and sleep cycles (made possible by an intact reticular
activating system, though destruction to the cerebrum precludes
consciousness); pupillary reaction to light and eyes movements; and
such reflexes as swallowing, gagging, and coughing. A rare form of
unconsciousness that is distinct from PVS and tends to lead fairly
quickly to death is
permanent
(
irreversible
)
coma
. This state, in which patients never appear to be awake,
involves partial brainstem functioning. Permanently comatose patients,
like PVS patients, can maintain breathing and heartbeat without
mechanical assistance.
With this background, we turn to the advantages and disadvantages of
the whole-brain approach. First, what considerations favor this
approach over the traditional focus on cardiopulmonary function in
determining death? The most prominent and arguably the most powerful
case for the whole-brain standard appeals to two considerations: (1)
the organismic definition of death and (2) an emphasis on the brain's
role as the primary integrator of overall bodily functioning. (Some
who regard a general definition of death as unnecessary have focused
on consideration (2) in defending the whole-brain standard. Some
others, as discussed later, have retained consideration (1) but
dropped consideration (2).) An additional consideration that has been
influential, yet is logically separable from the other two, is (3) the
thesis that the whole-brain standard updates, without replacing, the
traditional approach to defining death.
According to the organismic definition, death is the
irreversible
loss of functioning of the organism as a whole
(Becker 1975;
Bernat, Culver, and Gert 1981). Proponents of this approach emphasize
that death is a biological occurrence common to all organisms.
Although individual cells and organs live and die, organisms are the
only entities that literally do so without being parts of larger
biological systems. (Ideas, cultures, and machines live and die only
figuratively; cells and tissues are literally alive but are parts of
larger biological systems.) So an adequate definition of death must be
adequate in the case of all organisms. What happens when a paramecium,
clover, tree, mosquito, rabbit, or human dies? The organism stops
functioning as an integrated unit and breaks down, turning what was
once a dynamic object that took energy from the environment to
maintain its own structure and functioning into an inert piece of
matter subject to disintegration and decay. In the case of humans, no
less than other organisms, death involves the collapse of integrated
bodily functioning.
The whole-brain standard does not follow straightforwardly from the
organismic conception of death. One might insist, after all, that a
human organism's death occurs upon irreversible loss of
cardiopulmonary function. Why think the brain so important? According
to the mainstream whole-brain approach, the human brain plays the
crucial role of integrating major bodily functions so only the death
of the entire brain is necessary and sufficient for a human being's
death (Bernat, Culver, and Gert 1981). Although heartbeat and
breathing normally indicate life, they do not constitute life. Life
involves integrated functioning of the whole organism. Circulation and
respiration are centrally important, but so are maintenance of body
temperature, hormonal regulation, and various other functions—as
well as, in humans and other higher animals, consciousness. The brain
makes all of these vital functions possible. Their integration within
the organism is due to a central integrator, the brain.
This leading case for the whole-brain standard, then, consists in an
organismic conception of death coupled with a view of the brain as the
chief integrator of interdependent bodily functions. Another
consideration sometimes advanced in favor of the whole-brain standard
positions it as a part of time-honored tradition rather than a
departure from tradition. (The argument may be understood either as an
appeal to the authority of tradition or as an appeal to the
practicality of not departing radically from tradition.) The claim is
that the traditional focus on cardiopulmonary function is part and
parcel of the whole-brain approach, that the latter does not revise
our understanding of death but merely updates it with a more
comprehensive picture that highlights the brain's crucial role:
Three organs—the heart, lungs, and brain—assume special
significance … because their interrelationship is close and the
irreversible cessation of any one very quickly stops the other two and
consequently halts the integrated functioning of the organism as a
whole. Because they were easily measured, circulation and respiration
were traditionally the basic “vital signs.” But [they] are
simply used as signs—as one window for viewing a deeper and more
complex reality: a triangle of interrelated systems with the brain at
its apex. [T]he traditional means of diagnosing death actually
detected an irreversible cessation of integrated functioning among the
interdependent bodily systems. When artificial means of support mask
this loss of integration as measured by the old methods,
brain-oriented criteria and tests provide a new window on the same
phenomena (President's Commission 1981, 33).
According to this view, when the entire brain is nonfunctional but
cardiopulmonary function continues due to a respirator and perhaps
other life-supports, the mechanical assistance presents a false
appearance of life, concealing the absence of integrated functioning
in the organism as a whole.
The whole-brain approach clearly enjoys advantages. First, whether or
not the whole-brain standard really incorporates, rather than
replacing, the traditional cardiopulmonary standard, the former is at
least fairly continuous with traditional practices and understandings
concerning human death. Indeed, current law in the American states
incorporates both standards into disjunctive form, most states
adopting the Uniform Determination of Death Act (UDDA) while others
have embraced similar language (Bernat 2006, 40). The UDDA states 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 brainstem, is dead,” (President's Commission 1981,
119). Similar legal developments have occurred in Canada (Law Reform
Commission of Canada 1981; Canadian Congress Committee on Brain Death
1988). The close pairing of the whole-brain and cardiopulmonary
standards in the law suggests that the whole-brain standard does not
depart radically from tradition.
The present approach offers other advantages as well. For one, the
whole-brain standard is prima facie plausible as a specification of
the organismic definition of death in the case of human beings.
Moreover, acceptance of whole-brain criteria for death facilitates
organ transplantation by permitting a declaration of death and
retrieval of still-viable organs while respiration and circulation
continue, with mechanical assistance, in a “brain-dead”
body. Another practical advantage is permitting, without an advance
directive or proxy consent, discontinuation of costly life-support
measures on patients who have incurred total brain failure. While most
proponents of the whole-brain approach insist that such practical
advantages are merely fortunate consequences of the biological facts
about death, one might regard these advantages as part of the
justification for a standard whose defense requires more than appeals
to biology (see subsection 4.2 below).
The advantages proffered by this approach contributed to its
widespread social acceptance and legal adoption in the last few
decades of the 20
th
century. As mentioned, every American
state has legally adopted the whole-brain standard alongside the
cardiopulmonary standard as in the UDDA. It is worth noting, however,
that a close cousin to the whole-brain standard, the
brainstem
standard
, was adopted by the United Kingdom and various other
nations. According to the brainstem standard—which has the
practical advantage of requiring fewer clinical tests—human
death occurs at the irreversible cessation of brainstem function. One
might wonder whether a person's cerebrum could function—enabling
consciousness—while this standard is met, but the answer is no.
Since the brainstem includes the reticular activating system, the
on/off switch that makes consciousness possible (without affecting its
contents), brainstem death entails irreversible loss not only of
unassisted respiration and circulation but also of the capacity for
consciousness. Importantly, outside the English-speaking world, many
or most nations, including virtually all developed countries, have
legally adopted either whole-brain or brainstem criteria for the
determination of death (Wijdicks 2002). Moreover, most of the public,
to the extent that it is aware of the relevant laws, appears to accept
such criteria for death (ibid). Opponents commonly fall within one of
two main groups. One group consists of religious
conservatives—and, recently, a growing number of secular
academics—who favor the cardiopulmonary standard, according to
which one can be brain-dead yet alive if (assisted) cardiopulmonary
function persists. The other group consists of those liberal
intellectuals who favor the higher-brain standard (to be discussed),
which, notably, has not been adopted by any jurisdiction.
The widespread acceptance in the U.S. of the whole-brain standard and
the broader international acceptance of some sort of “brain
death” criteria—whether whole-brain or brainstem—are
remarkable considering the subtlety of issues surrounding the
definition and determination of death. Yet this near-consensus has
been broader than it is deep. Increasingly, both in academic and
clinical circles, doubts about “brain death” are being
voiced. Following are several major challenges to the whole-brain
standard—and, implicitly, to the brainstem standard. (Several
additional challenges are implicit in arguments supporting the
higher-brain approach.)
The first challenge is directed at proponents of the whole-brain
approach who claim that its standard merely updates, without
replacing, the traditional cardiopulmonary standard. A major
contention that motivates this thesis is that irreversible cessation
of brain function will quickly lead to irreversible loss of
cardiopulmonary function (and vice versa). But extended maintenance on
respirators of patients with total brain failure has removed this
component of the case for the whole-brain standard (PCB 2008, 90). The
remaining challenges to the whole-brain approach are not specifically
directed to those who assert that its standard merely updates the
traditional cardiopulmonary standard.
First, in the case of at least some members of our species, total
brain failure is not
necessary
for death. After all, human
embryos and early fetuses can die although, lacking brains, they
cannot satisfy whole-brain criteria for death (Persson 2002,
22–23). An advocate could respond by introducing a modified
definition:
In the case of any human being in possession of a
functioning brain
, death is the irreversible cessation of
functioning of the entire brain. While this may be practically useful
in the world as we know it for the foreseeable future, this definition
is not conceptually satisfactory if it is possible in principle for
some human beings with brains (that is, who have functioning brains at
any point in their existence) to die without destruction of their
brains. The “in principle” is important here, for this is
not possible in our world currently. But suppose we develop the
ability to transplant brains. (The thought-experiment that follows
appears in McMahan 2002, 429.) Recall that the whole-brain standard is
generally thought to receive support from an organismic definition of
death. But such a conception of human death, one could argue, only
makes sense on the assumption that we are essentially human organisms
(see discussion of the essence of human persons in section
2.1)—as some proponents explicitly acknowledge (see, e.g., Olson
1997). According to the present critique, the brain is merely a
part
of the organism. Suppose the brain were removed from one
of us, and kept intact and functioning, perhaps by being transplanted
into another, de-brained body. Bereft of mechanical assistance, the
body from which the brain was removed would surely die. But this body
was the living organism, one of us. So, although the original brain
continues to function, the human being, one of us, would have died.
Total brain failure, then, is not strictly necessary for human death.
A possible rebuttal to this challenge from one who accepts that we are
essentially organisms is to argue that the existence of a functioning
brain is sufficient for the continued existence of the organism (van
Inwagen 1990, 173–174, 180–181). If so, then in the
imagined scenario the original human being would survive the brain
transplant in a new body. Thus, the rebuttal concludes, it is false
that a human being could die although her brain continued to live.
Perhaps more threatening to the whole-brain approach is the growing
empirical evidence that total brain failure is not
sufficient
for human death —assuming the latter is construed, as
whole-brain advocates generally construe it, as the breakdown of integrated
organismic functioning mediated by the brain. Many of our integrative
functions, according to the challenge, are not mediated by the brain
and can therefore persist in individuals who meet whole-brain criteria
for death by standard clinical tests. Such somatically integrating
functions include homeostasis, assimilation of nutrients,
detoxification and recycling of cellular wastes, elimination, wound
healing, fighting of infections, and cardiovascular and hormonal
stress responses to unanesthetized incisions (for organ procurement);
in a few cases, brain-dead bodies have even gestated a fetus, matured
sexually, or grown in size (Shewmon 2001; Potts 2001). It has been
argued that most brain functions commonly cited as integrative merely
sustain an existing functional integration, suggesting that the brain
is more an enhancer than an indispensable integrator of bodily
functions (Shewmon 2001). Moreover, several studies have demonstrated
that most patients diagnosed as brain dead continue to exhibit some
brain functions including the regulated secretion of vasopressin, a
hormone critical to maintaining a body's balance of salt and fluid
(Halevy 2001). This hormonal regulation is a brain function that
represents an integrated function of the organism as a whole (Miller
and Truog 2010).
Another, related problem for the sufficiency of total brain failure
for human death arises from reflection on
locked-in syndrome
.
People with locked-in syndrome are conscious, and therefore alive, but
completely paralyzed with the possible exception of their eyes. With
intensive medical support they can live. The interesting fact for our
purposes is that some patients with this syndrome exhibit no more
somatic functioning integrated by the brain than some brain-dead
individuals. Whatever integration of bodily functions remains is
maintained by external supports and by bodily systems other than the
brain, which merely preserves consciousness (Bartlett and Youngner
1988, 205–6). If total brain failure is supposed to be
sufficient for death, and if this is true
only because
the
former entails the loss of somatic functioning integrated by the
brain, then the loss of those functions should also be sufficient for
death. But these patients, who are clearly alive, show that this is
not so. Either the whole-brain definition must be rejected
or
this particular reason for accepting the whole-brain approach must be
rejected and some other good reason for accepting it found.
Recently, a new rationale—distinct from the one that understands
human death in terms of loss of organismic functioning mediated by the
brain—has been advanced in support of the whole-brain standard
(PCB 2008, ch. 4). According to this rationale, a human being dies
upon irreversibly losing the capacity to perform the
fundamental
work
of an organism, a loss that occurs with total brain failure.
The fundamental work of an organism is characterized as follows: (1)
receptivity to stimuli from the surrounding environment; (2) the
ability to act upon the world to obtain, selectively, what the
organism needs; and (3) the basic felt need that drives the organism
to act as it must to obtain what it needs and what its receptivity
reveals to be available (ibid, 61). According to a sympathetic reading
of the ambiguous discussion in which this analysis is advanced, any
patient who meets even one of these criteria is alive and therefore
not dead. A patient with total brain failure meets none of these
criteria, even if a respirator permits the continuation of
cardiopulmonary function. By contrast, PVS patients meet at least the
second criterion through spontaneous respiration (a kind of acting
upon the world to obtain what is needed: oxygen); and locked-in
patients meet the first criterion if they can see or experience bodily
sensation and certainly meet the third insofar as they are conscious.
One difficulty with this “fundamental work” rationale for
the whole-brain standard, a rationale that is intended to capture
“what distinguishes every organism from non-living things”
(ibid), is that some present-day robots, which are certainly not alive,
seem to satisfy the first two criteria. If one insisted, contrary to
the reading deemed sympathetic, that a being must satisfy all three
criteria—as robots do not since they lack felt needs—in
order to qualify as living, the same may be asserted not only of
insentient animal life but also of presentient human fetuses and of
unconscious human beings of any age. Another difficulty of the
“fundamental work” rationale for the whole brain standard is that it
was intended to replace the idea that integrated functional unity
within an organism is what constitutes life—but the latter idea
is extremely plausible and helps to explain what any “fundamental
work” would be working toward (cf. Thomas 2012, 105). Whether any variation
or modification of the present rationale for the whole-brain standard
can survive critical scrutiny remains an open question.
Some traditional defenders of the cardiopulmonary approach believe
that the insufficiency of whole-brain criteria for death is evident
not only in exceptional cases, such as those described earlier, but in
all cases in which patients with total brain failure exhibit
respirator-assisted cardiopulmonary function. Anyone who is breathing
and whose heart functions cannot be dead, they claim. The champion of
whole-brain criteria may retort that such a body is not really
breathing and circulating blood; the respirator is doing the work. The
traditionalist, in response, will likely contend that what is
important is not who or what is powering the breathing and heartbeat,
just that they occur. Even complete dependence on external support for
vital functions cannot entail that one is dead, the traditionalist
will continue, as is evident in the fact that living fetuses are
entirely dependent on their mothers' bodies; nor can complete
dependence on mechanical support entail that one is dead, as is
evident in the fact that many living people are utterly dependent on
pacemakers.
A third major criticism of the whole-brain approach—at least in
its legally authoritative formulation in the United
States—concerns its conceptual and clinical adequacy. The
whole-brain standard, taken at its word, requires for human death
permanent cessation of
all
brain functions. Yet many patients
who meet routine clinical tests for this standard continue to have
minor brain functions such as electroencephalographic activity,
isolated nests of living neurons, and hypothalamic functioning (see,
e.g., Potts 2001, 482; Veatch 1993, 18; Nair-Collins and Miller
forthcoming). Indeed, the latter, which controls neurohormonal
regulation, is indisputably an
integrating
function of the brain (Brody 1999, 73). Now one
could maintain the coherence of the whole-brain approach by insisting
that the individuals in question are not really dead and that
physicians ought to use more thorough clinical tests before declaring
death (see, e.g., Capron 1999, 130–131). But whole-brain
theorists tend to agree that these individuals are dead—that the
residual functions are too trivial to count against a judgment of
death (see, e.g., President's Commission 1981, 28–29; Bernat
1992, 25)—suggesting that the problem lies with the formulation
of the whole-brain standard rather than with its spirit.
Within this spirit and in response to this challenge, a leading
proponent of the whole-brain approach has revised both (1) the
organismic definition of death to “the permanent cessation of
the
critical
functions of the organism as a whole” and
(2) the corresponding standard to permanent cessation of the
critical
functions of the whole brain (Bernat 1998, 17). The
organism's critical functions may be identified by reference to its
emergent
functions—that is, properties of the whole
organism that are not possessed by any of its component parts—as
follows: “The irretrievable loss of the organism's emergent
functions produces loss of the critical functioning of the organism as
a whole and therefore is the death of the organism,” (Bernat
2006, 38). The emphasis on critical functions, of course, allows one
to declare dead those patients with only trivial brain functions.
According to this revised whole-brain approach, the critical functions
of the organism are (1) the vital functions of spontaneous breathing
and autonomic circulation control, (2) integrating functions that
maintain the organism's homeostasis, and (3) consciousness. A human
being dies upon losing all three. Whether this or some similar
modification of the whole-brain approach adequately addresses the
present challenge is a topic of ongoing debate (see, e.g., Brody 1999,
Bernat 2006). What seems reasonably clear is that not all functions of
the brain will count equally in any cogent defense of the whole-brain
approach.
The judgment that some brain functions are trivial in this context
invites a reconsideration of what is most significant about what the
human brain does. According to an alternative approach, what is far
and away most significant about human brain function is
consciousness.
According to the higher-brain standard,
human death is the
irreversible cessation of the capacity for consciousness
.
“Consciousness” here is meant broadly, to include any
subjective experience, so that both wakeful and dreaming states count
as instances. Reference to the
capacity
for consciousness
indicates that individuals who retain intact the neurological hardware
needed for consciousness, including individuals in a dreamless sleep
or reversible coma, are alive. One dies on this view upon entering a
state in which the brain is incapable of returning to consciousness.
This implies, somewhat radically, that a patient in a PVS or irreversible
coma is dead despite continued brainstem function that permits
spontaneous cardiopulmonary function. Although no jurisdiction has
adopted the higher-brain standard, it enjoys the support of many
scholars (see, e.g., Veatch 1975; Engelhardt 1975; Green and Wikler
1980; Gervais 1986; Bartlett and Youngner 1988; Puccetti 1988; Rich
1997; and Baker 2000). These scholars conceptualize, or define, human
death in different ways—though in each case as the irreversible
loss of some property for which the capacity for consciousness is
necessary. This discussion will consider four leading argumentative
strategies in support of the higher-brain approach.
One strategy for defending the higher-brain approach is to appeal to
the essence of human persons on the understanding that this essence
requires the capacity for consciousness (see, e.g., Bartlett and
Youngner 1988; Veatch 1993; Engelhardt 1996, 248; Rich 1997; and Baker
2000, 5). “Essence” here is intended in a strict
ontological sense: that property or set of properties of an individual
the loss of which would necessarily terminate the individual's
existence. From this perspective, we human persons—more
precisely, we individuals who are at any time human persons—are
essentially
beings with the capacity for consciousness such
that we cannot exist at any time without having this capacity at that
time. We go out of existence, it is assumed, when we die, so death
involves the loss of what is essential to our existence.
Unfortunately, the use of terminology in these arguments can be
confusing because the same term may be used in different ways and
terms are frequently used without precise definition. It is sometimes
claimed, for example, that we are essentially
persons
. But
what, exactly, is a person? Some authors (e.g., Engelhardt 1996, Baker
2000) use the term to refer to beings with relatively complex
psychological capacities such as self-awareness over time, reason, and
moral agency. Then the claim that we are essentially persons implies
that we die upon losing such advanced capacities. But this means that
at some point
during
the normal course of progressive
dementia the demented individual dies—upon losing complex
psychological capacities, however these are defined—
despite
the fact that a patient remains, clearly alive, with the capacity for
(basic) consciousness
. This view is extraordinarily radical and
appears inconsistent with the higher-brain approach, which equates
death with the irreversible loss of the capacity for (any) consciousness.
A proponent of the view that we are essentially persons in the present
sense, however, may hold that practical considerations—such as
the impossibility of drawing a clear line between sentient persons and
sentient nonpersons, and the potential for abuse of the
elderly—recommend the capacity for consciousness as the only
safe line to draw, thereby vindicating the higher-brain view
(Engelhardt 1996, 250). Meanwhile, other proponents of the view that
we are essentially persons (e.g., Bartlett and Youngner 1988)
apparently hold that any member of our species who retains the
capacity for consciousness qualifies as a person. This view, unlike
the previous one, straightforwardly supports the higher-brain
standard. Still other authors (e.g., Veatch 1993) hold that we are
essentially
human beings
where this term refers not to all
members of our species but just to those judged to be persons by the
previous group of authors: members of our species who have the
capacity for consciousness. And some authors who defend the
higher-brain standard (e.g., McMahan 2002) assert that we are
essentially
minds
or
minded beings
, which is to say
beings with the capacity for consciousness. In each case, an appeal to
our essence is advanced to support the higher-brain standard.
Taking this collection of arguments together, the reasoning might be
reconstructed as follows:
- For humans, the irreversible loss of the capacity for
consciousness entails (is sufficient for) the loss of what is
essential to their existence;
- For humans, loss of what is essential to their existence is (is
necessary and sufficient for) death;
Therefore,
- For humans, irreversible loss of the capacity for consciousness
entails (is sufficient for) death.
We have noted that various commentators who advance this reasoning
hold that we are essentially persons in a sense requiring complex
psychological capacities. We have noted that this implies that for
those of us who become progressively demented, we die—go out of
existence—at some point
during
the gradual slide to
permanent unconsciousness. Even if practical considerations recommend
safely drawing a line at irreversible loss of the capacity of
consciousness for policy purposes, the implication that, strictly
speaking, we go out of existence
during
progressive dementia
will strike many as incredible. At the other end of life there is
another problematic implication. For if we are essentially persons (in
this sense), then inasmuch as human newborns lack the capacities that
constitute personhood, each of us came into existence
after
what is ordinarily described as
his or her
birth.
For those attracted to the general approach of understanding our
essence in terms of psychological capacities, a promising alternative
thesis is that we are essentially beings with the capacity for at
least some form of consciousness who die upon irreversibly losing that
very basic capacity. Stated more simply, we are essentially minded
beings, or minds, and we die when we completely “lose our
minds.” (Note that this thesis is consistent with the claim that
we are also essentially embodied.)
What, then, about the human organism associated with one of us minded
beings? Surely the fetus that gradually developed prior to the
emergence of sentience or the capacity for consciousness—that
is, prior to the emergence of a mind—was alive. On the other end
of life, a patient in a PVS who is spontaneously breathing,
circulating blood, and exhibiting a full range of brainstem reflexes
appears to be alive. Consider also anencephalic infants, who are born
without cerebral hemispheres and never have the capacity for
consciousness: They, too, seem to be living organisms, their grim
prognosis notwithstanding. In response to this challenge, a proponent
of the higher-brain approach may either (1) assert that the
presentient fetus, PVS patient, and anencephalic infant are not alive
despite appearances (Puccetti 1988) or (2) allow that these organisms
are alive but are not of the same fundamental kind as we are: minded
beings (McMahan 2002, 423–6). Insofar as life is a biological
concept, and the organisms in question satisfy commonly accepted
criteria for life, option (1) seems at best hyperbolic. At best, the
claim is really that these organisms, though alive, are not alive in
any state that matters much, so we may count them as dead or nonliving
for our purposes. This claim, in turn, may be understood as depending
on option (2), on which we may focus. This option implies that for
each of us minded beings, there is a second, closely associated being:
a human organism. The prospects of the present strategy for defending
the higher-brain approach turn significantly on its ability to make
sense of this picture of two closely associated beings: (1) the
organism, which comes into existence at conception or shortly
thereafter (perhaps after twinning is no longer possible) and dies
when organismic functioning radically breaks down, and (2) the minded
being, who comes into existence when sentience emerges and
might—in the event of PVS or irreversible coma—die before the
organism does. (For doubts on this score, see DeGrazia 2005, ch.
2).
Appealing to the authority of biologists and common sense, some
philosophers (e.g., Olson 1997) charge as indefensible the claim that
we (who are now) human persons were never presentient fetuses. One
might also find puzzling the thesis that there is one definition of
death, appealing to the capacity for consciousness, for human beings
or persons and another definition, appealing to organismic
functioning, for nonhuman animals and the human organisms associated
with persons. It is open to the higher-brain theorist, however, to
allow that there are also two closely associated beings in the case of
sentient nonhuman animals—the minded being and the
organism—with the death of, say, Lassie (the minded dog)
occurring at her irreversible loss of consciousness (McMahan 2002, ch.
1). But some will find unattractive the failure to furnish a single
conception of death that applies to all living things. To be sure, not
everyone finds these objections compelling.
One of the most significant challenges confronting the present
approach is to characterize cogently the relationship between one of
us and the associated human organism. The relationship is clearly not
identity
—that is, being one and the same
thing—because the organism originates before the mind, might
outlive the mind, and therefore has different persistence conditions.
This strongly suggests, perhaps surprisingly, that we human persons
are not animals. If you are not identical to the human organism
associated with you, then since there is at most one animal sitting in
your chair, you are not she and are therefore not an animal (Olson
1997). Yet many consider it part of educated common sense that we are
animals.
Might you be
part
of the organism associated with
you—namely, the brain (more precisely, the portions of the brain
associated with consciousness) (McMahan 2002, ch. 1)? But the brain
seems capable of surviving death, when you are supposed to go out of
existence. Are you then a
functioning
brain, which goes out
of existence at the irreversible loss of consciousness? But it seems
odd to identify the
functioning
brain—as distinct from
the brain—as you. How could you be some organ only when it
functions? Presumably you are a
substance
(see the entry on
substance
),
a bearer of properties, not a substance
only when it has certain
properties
. One might reply that the functioning brain is itself
a substance, a substance distinct from the brain, but that, too,
strains credibility. Might you instead be not the brain, but the mind
understood as the
conscious properties
of the brain? That
would imply that you are a set of properties, rather than a substance,
which is no less counterintuitive. Note that the charge of
incredibility is not directed at the assertion that the
mind
is the functioning brain, or is a set of brain properties, and not a
distinct substance—a thesis in good standing in the philosophy
of mind (see the entries on
identity theory of mind
and
functionalism
).
The charge of incredibility is directed at the assertion that
you
are a set of properties and not a
substance.
[
2
]
Another possibility regarding the person/organism relationship is that
the human organism
constitutes
the person it eventually comes
to support (Baker 2000). One might even claim the legitimacy of
saying—employing an “is” of constitution—that
we
are
animals (or organisms), just as we can say that a
statue constituted by a hunk of bronze, shaped in a particular way, is
a hunk of bronze (ibid). Challenges to this reasoning includes doubts
that we may legitimately speak of an “is” of constitution;
if not, then the constitution view implies that we are not animals
after all. Another challenge, which applies equally to the view that
we minds are parts of organisms, concerns the counting of conscious
beings. On either the constitution view or the part-whole view, you
are essentially a being with the capacity for consciousness. Closely
associated with you—without being (identical to) you, due to
different persistence conditions—is a particular animal. But
that animal, having a functioning brain, would also seem to be a
conscious being. Either of these views, then, apparently suggests that
for each of us there are two conscious beings, seemingly one too many.
Despite such difficulties as these, the thesis that we are essentially
minded beings remains a significant basis for the higher-brain approach to human death.
A second argumentative strategy in defense of the higher-brain
approach claims to
appeal to our personal identity while remaining
agnostic on the question of our essence
(Green and Wikler 1980).
The fundamental claim is that, whatever we are essentially, it is
clear that one of us has gone out of existence once the capacity for
consciousness has been irreversibly lost, supporting the higher-brain
standard of death. Clearly, though, any view of our numerical identity
over time—our persistence conditions—is conceptually
dependent on a view of what we essentially are (DeGrazia 1999;
DeGrazia 2005, ch. 4). If we are essentially human animals, and not
essentially beings with psychological capacities, then, contrary to
the above argument, it is not clear—indeed, it is
false—that we go out of existence upon irreversible loss of the
capacity for consciousness; rather, we die upon the collapse of
organismic functioning. The appeal to personal identity in support of
the higher-brain standard depends on the thesis that we are
essentially minded beings and therefore inherits the challenges facing
this view, as discussed in the previous subsection. Nevertheless, the
appeal to personal identity, construed as a distinct argumentative
strategy, was somewhat influential in early discussions of the definition of death (see, e.g., President's
Commission 1981, 38–9).
Another prominent argumentative strategy in support of the
higher-brain approach contends that
the definition of death is a
moral issue and that confronting it as such vindicates the
higher-brain approach
(see, e.g., Veatch 1975, 1993; Gervais
1986, ch. 6). In asking how to determine that a human has died,
according to this argument, what we are really asking is when we ought
to discontinue certain activities such as life-support efforts and
initiate certain other activities such as organ donation, burial or
cremation, grieving, change of a survivor's marital status, and
transfer of property. The question, in other words, is when
“death behaviors” are appropriate. This, the argument
continues, is a moral question, so an answer to this question should
be moral as well. Understood thus, the issue of defining human death
is best addressed with the recognition that irreversible loss of the
capacity for consciousness marks the time at which it is appropriate
to commence death behaviors.
Is the definition of death really a moral issue? To say that someone
has died does seem tantamount to saying that certain behaviors are now
appropriate while certain others are no longer appropriate. But it
hardly follows that the assertion of death is itself a moral claim. An
alternative hypothesis is that the sense of moral import derives from
the fact that certain moral premises—for example, that we
shouldn't bury or cremate prior to death—are shared by virtually
everyone. Moreover, the concept of death is (at least originally) at
home in biology, which offers many instances in which a determination
of death—say, of a gnat or a clover—seems morally
unimportant. Rather than asserting that death itself is a moral
concept, it might be more plausible to assert that death, a biological
phenomenon, is generally assumed to be morally important—at
least in the case of human beings—given a relatively stable
background of social institutions and attitudes about “death
behaviors.” Furthermore, due to the moral salience of human
death, discussions about its determination are often prompted by a
moral or pragmatic agenda such as interest in organ transplantation or
concerns about expensive, futile treatment. But these observations do
not imply that death is itself a moral concept.
Even if it were, it would hardly follow that the higher-brain standard
is preferable to other standards. A person with relatively
conservative instincts might hold that death behaviors are morally
appropriate only when the whole-brain or cardiopulmonary standard has
been met. We need to ask, therefore, what grounds exist for the
claim—advanced by proponents of the higher-brain
standard—that death behaviors are appropriate as soon as someone
has irreversibly lost the capacity for consciousness. Perhaps the best
possible grounds are that irreversible loss of consciousness entails
an existence lacking in value
for the unconscious individual
herself
. It appears, then, that the strongest specification of
the present line of reasoning actually relies upon the next (and
final) argumentative strategy to be considered—and might, as we
will see, lead to the conclusion that we should permit individuals to
select among several standards of death.
The idea here is to defend the higher-brain approach on the basis of
claims about prudential value (for a discussion, see DeGrazia 2005,
134–8). Conscious life, it is argued, is a precondition for
virtually everything that we value in our lives. We have an enormous
stake in continuing our lives as persons and little or no stake in
continuing them when we are permanently unconscious. The capacity for
consciousness is therefore
essential
not in a metaphysical
sense connected to our persistence conditions, but in the evaluative
sense of
indispensable to us
. One need not claim that the
capacity for consciousness underlies everything of prudential value,
just that it underlies the overwhelmingly greater part of what matters
to us prudentially. And although, for many people, consciousness may
not be
sufficient
for what matters prudentially—insofar
as they find indispensable, say, some degree of self-awareness and
meaningful interaction with others—it is certainly necessary;
and the basic capacity for consciousness (as opposed to
self-consciousness or personhood) is the only safe place to demarcate
death for policy and social purposes. We should therefore regard
irreversible loss of the capacity for consciousness as a human being's
death—even if the original concept of death is biological and
biological considerations favor some less progressive standard.
How persuasive is this case for the higher-brain approach? One might
challenge the assumption that prudential, as opposed to moral,
considerations ought to be decisive in adopting a standard for human
death. On the other hand, as suggested in our discussion of the
previous argumentative strategy, moral considerations may not favor a
particular standard of death except insofar as they rest on prudential
considerations—our present concern. But even if we accept the
claim that human death should be understood on the basis of prudential
values, we confront the prospect of reasonable pluralism about
prudential value. While supporters of the higher-brain approach (who
tend to be liberal intellectuals) are likely to have prudential values
in line with this approach, many other people do not. If a patient has
a stake in his family's need for closure should he enter a
PVS—an interest that may be self-regarding as well as
other-regarding—this fact would count against allowing the PVS
to constitute death in his case. If an Orthodox Jew or conservative
Christian believes that (biological) life is inherently precious to
its possessor, even if the individual cannot appreciate its value at a
given time, this would count against the higher-brain standard in the
case of the individual in question. Perhaps, then, the appeal to
prudential value favors not the higher-brain standard for everyone but
a
pro-choice view about standards of death
. A jurisdiction
might, for example, have one default standard of death but permit
conscientious exemption from that standard and selection of a
different one within some reasonable range of options (Veatch 2019).
In reply to this argument, a proponent of the appeal to prudential
value might contend that it is simply irrational to value biological
existence without the possibility of returning to consciousness. But
this reply assumes the
experience requirement
: that only
states of affairs that affect one's experience can affect one's
well-being (for a discussion, see Griffin 1986, 16–19). The
experience requirement is not self-evident. Some people believe that
they are worse off for being slandered even if they never learn of the
slander and its repercussions never affect their experience. Some even
believe, following Aristotle's suggestion, that the quality of one's
life as a whole can be affected by posthumous states of affairs such
as tragedy befalling a loved one. Although the intelligibility of this
belief in posthumous interests might be challenged, the following is
surely intelligible: States of affairs that don't affect one's
experience but connect importantly with one's values can affect one's
interests
at least while one exists
. Desire-based accounts of
well-being (see, e.g., Hare 1981) standardly accept this principle,
for what is desired may occur without one's awareness of its
occurrence and without affecting one's experience. These
considerations illuminate the intelligibility of one's prudential
values extending to a period of time when one is alive but
irreversibly unconscious.
In view of apparently reasonable pluralism regarding prudential
values, including reasonable disagreement about the experience
requirement, it seems doubtful that appeal to prudential value alone
can support the higher-brain standard for everyone. At the same time,
and more generally, the higher-brain approach remains an important
contender in the debate over the definition of death.
Prior to the brain-death movement, death was traditionally understood
along the lines of the
cardiopulmonary standard
: death as the
irreversible cessation of cardiopulmonary function
. In the
supportive background of this consensus on the cardiopulmonary
standard hovered several general definitions or conceptualizations of
death. Some champions of the traditional standard (e.g., Becker 1975)
have conceptualized death in the same organismic terms that proponents
of the whole-brain standard invoke: death as the irreversible
cessation of functioning of the organism as a whole. Other champions
of tradition have conceptualized death in more spiritual terms such as
the departure of the animating (or vital) principle
or
loss of the soul.
In determining whether someone was dead, one could check for a pulse,
moisture on a mirror held in front of the mouth, or other indications
that the heart and lungs were working. Before the development of
respirators and other modern life-supports, a working heart and lungs
indicated continuing brainstem function. As we have seen, however,
modern life-supports permitted cardiopulmonary function without brain
function, setting up a competition between traditional and whole-brain
criteria for determining death. Although, as noted above, the
whole-brain approach achieved near-consensus status, this approach is
increasingly questioned and faces significant difficulties. Its
difficulties and those facing the more radical higher-brain
alternative have contributed to renewed interest in the traditional
approach.
Further contributing to renewed interest in the traditional
approach—and warranting a brief digression—is an approach
to organ donation that capitalizes on the fact that current American
legal standards for death are disjunctive, permitting satisfaction of
either the whole-brain standard or the cardiopulmonary standard,
whichever applies first, for a declaration of death. This approach to
organ donation, called
donation after cardiac death
(DCD) or
non-heart-beating organ donation
, was very rare until
instituted with much publicity by the University of Pittsburgh in the
early 1990s in response to a perception that awaiting a neurological
determination of death for (heart-beating, respirator-maintained)
organ donors was insufficient to meet the demand for viable organs. In
the Pittsburgh program, a respirator-dependent patient who had
previously agreed to forgo life supports and donate vital organs is
taken to an operating room and disconnected from the respirator,
leading predictably to cardiac arrest. Two minutes after cardiac
arrest, the patient is declared dead on the basis of the
cardiopulmonary standard: “irreversible cessation of circulatory
and respiratory functions.” This procedure allows organ
procurement to commence very shortly after cardiac arrest, providing
relatively fresh organs for transplant. (Organs, of course, would not
be viable if medical staff awaited a declaration of total brain
failure—which requires confirmatory tests hours after initial
tests—in the patients in question, who will not incur total
brain failure unless respirator support is discontinued.)
The practice of DCD, which has expanded to several medical centers,
has provoked considerable controversy. Critics have charged that in
DCD vital organs are removed before patients are really dead, implying
that organ procurement kills the patients. Some proponents of the
whole-brain approach argue that the patients are not yet dead because
only total brain failure (or perhaps that of the brainstem)
constitutes human death. But current American law in its disjunctive form
suggests otherwise—at least for legal purposes. Other critics of
DCD charge that a patient cannot be dead two minutes after cardiac
arrest because the loss of cardiopulmonary functioning is not
irreversible: Victims of heart attack are sometimes revived more than
two minutes after the arrest. One might reply that the loss of
functioning is irreversible because, the patient having requested
removal of life supports, no one
may
violate the patient's
rights by resuscitating him or her (Tomlinson 1993). It seems fair to
reply, however, that a decision not to resuscitate does not mean that
resuscitation is
impossible
as suggested by the concept of
irreversibility
. Has the latter concept been conflated in DCD
with the concept of
permanence
? Permanent loss of function
does not imply that resuscitation is impossible, just that it will not
occur.
[
3
]
These concerns about abandoning the standard of irreversible loss of
cardiopulmonary function apply even to more modest proposals, such as
that advanced by the Institute of Medicine (2000), in which a
declaration of death and DCD proceed after a waiting period of
five
minutes: Resuscitation is sometimes possible more than
five minutes after a heart attack. Proponents of DCD might reply that
permanence, rather than irreversibility, is the appropriate standard
in this context (see, e.g., Bernat 2006, 41) or that DCD represents an
instance where it is permissible to remove vital organs from someone
who is dying but not yet dead. Certainly, any proponent of DCD will
see the current law's (disjunctive) acceptance of cardiopulmonary
criteria for death as offering a major practical advantage over any
policy that accepted only whole-brain criteria.
We return to the view of those who champion
only
the
cardiopulmonary standard. Proponents of this approach believe that it
correctly implies, contrary to competing standards, that a human body
that is breathing and maintaining circulation is alive regardless of
whether continuation of these functions requires external support (as
with “brain-dead” patients, locked-in patients, and normal
fetuses) (Shewmon 2001; Potts 2001). At the same time, the usual
characterization of the traditional approach is problematic in
suggesting that the difference between human life and death comes down
to the state of two organs: heart and lungs. This reductionistic
picture arguably obscures the holistic nature of bodily
functioning.
A more realistic picture, some argue, features integrative unity as
existing diffusely throughout the organism. As a leading proponent
puts it, “What is of the essence of integrative unity is neither
localized nor replaceable: namely the anti-entropic mutual interaction
of all the cells and tissues of the body, mediated in mammals by
circulating oxygenated blood” (Shewmon 2001, 473). On this view,
the brain, like the heart and lungs, is a very important component of
the interaction among body systems, but is not the supremely important
integrator as suggested by the (mainstream) whole-brain approach. Nor
is the functioning of other organs and bodily systems passively
dependent on the brain. The brain's capacity to augment other systems
presupposes their preexisting capacity to function. This is true even
of a brain function as somatically integrating as the maintenance of
body temperature: the “thermostat” may be in the brain,
but the “furnace” is the energy metabolism diffused
throughout the body. If not covered with blankets, brain-dead bodies
maintained on respirators will grow colder—but not comparably to
corpses (ibid, 471).
Although a realistic picture of organismic functioning must be
holistic, according to this updated traditional approach, it should
also portray certain functions as central. Tradition is correct that
respiration and circulation are especially crucial, but respiration is
not simply lung function and circulation is not just a working heart.
Both organs, after all, can be artificially replaced as the organism
maintains integrated functioning. Respiration and circulation occur
throughout the body as oxygenated blood circulates to different organs
and bodily systems—a condition necessary and sufficient for the
integrated organismic functioning that constitutes life. Unlike
whole-brain and higher-brain death, loss of respiration and
circulation leads relentlessly to the breakdown of cells, tissues,
organs, bodily systems, and eventually the organism as a whole. Hence
an updated traditional standard, which we might call the
circulatory-respiratory standard
: death as the
irreversible cessation of circulatory-respiratory
function
.
The chief advantage of such an updated traditional approach, according
to proponents, is that it most adequately characterizes the difference
between life and death—where the latter is understood in terms
of organismic functioning—in a full range of cases. Such cases
include several that the whole-brain and higher-brain standards handle
less plausibly such as prenatal human organisms prior to brain
development as well as locked-in patients and “brain-dead”
individuals whose vital functions are maintained with mechanical
assistance. The present approach also avoids some of the conceptual
problems facing the higher-brain approach, as discussed earlier.
Nevertheless, the traditional approach, whether updated or not, faces
significant issues. One concern is that the approach overemphasizes
our biological nature, suggesting we are nothing more than organisms,
and by demoting the brain from prominence underemphasizes the mental
life that is generally thought to distinguish our species from others.
We human beings are not merely organisms or animals, the argument
continues; we are also (after normal development) conscious beings and
persons whose nature, one might say, is to transcend nature with
culture. Our conception of human death should be faithful to a species
self-image that does justice not only to our animality but also to our
personhood (cf. Pallis 1999, 96).
Whole-brain (or brainstem) theorists and higher-brain theorists will
extend this line of argument in different directions. The higher-brain
theorist will suggest that our capacity for consciousness, a
precondition for higher capacities and personhood, is so important
that permanent loss of the basic capacity should count as death. The
whole-brain theorist who develops the present line of reasoning will
maintain greater contact with the organismic conception of death,
stressing the brainstem's role in integrating vital functions and
claiming either that (a) consciousness is a critical function of the
organism, permitting it to interact adaptively to its environment
(Bernat 1998), (b) consciousness is a characteristic aspect of the
fundamental work of organisms like us, or (c) consciousness is crucial
to our personhood, a feature no less important to what we are than our
animality. The latter option, in effect, would move the whole-brain
theorist to a dual-aspect understanding of human nature, as just
discussed: human persons as essentially
both
persons
and
animals (cf. Schechtman 2014).
A second major challenge confronting any traditional approach is the
specter of highly unpalatable practical consequences (Magnus, Wilfond, and Caplan 2014). Currently the
whole-brain standard is enshrined in law. Suppose we reversed
legislative course and returned to traditional criteria (whether
updated in formulation or not). Then a patient who satisfied
whole-brain criteria but not traditional criteria would count as alive. Unless we overturned the
“dead-donor rule”—the policy of permitting
extraction of vital organs only from dead bodies—then it would
be illegal to procure organs from these living patients who have
incurred total brain failure; yet the viability of their organs would
require maintaining respiration and circulation with life-supports.
There is broad agreement that having to wait until traditional
criteria are met to harvest organs would constitute a great setback to
organ transplantation (even if donation after cardiac death, which
invokes traditional criteria, is permitted). Moreover, a legal return
to traditional criteria for death might lead physicians to feel they
had lost the authority to discontinue treatment
unilaterally—when a family requests continued
treatment—upon a determination of total brain failure despite
what many would consider the futility of further treatment.
Furthermore, laws for determining death would have to be revised.
A defender of tradition might respond that we can avoid most of these
unsavory consequences while legally adopting traditional criteria for
determining death (see, e.g., DeGrazia 2005, 152–8). We could,
for one thing, abandon the dead-donor rule, permitting the harvesting
of vital organs when authorized by appropriate prospective consent of
the donor even though taking the organs, by causing the donor's death,
would instantiate killing (Truog and Robinson 2003; Sade 2011). We
could also authorize physicians—through hospital policies,
professional guidelines, or laws—to withdraw
life-supports unilaterally upon a declaration of total brain failure (perhaps even
upon a determination of irreversible unconsciousness) in cases where
continued treatment is unnecessary for organ procurement and appears
otherwise futile. Not all of what are traditionally considered
“death behaviors” need to be permanently anchored to a
declaration of death. Thus we currently use advance directives and
other considerations to justify withdrawal of life-supports in some
circumstances, although several decades ago such withdrawal had to
await a determination of death. There is no reason to regard further
reforms of our practices surrounding death as beyond responsible
consideration. Thus, despite rowing against the tide of the
brain-death movement, the traditional approach has reclaimed the
status of a serious contender in the debate over the definition of
death.
In recent decades, the debate over the definition of death has
generally been understood as a competition between the approaches
discussed here: traditional, whole-brain (or brainstem), and
higher-brain standards and their corresponding conceptualizations.
Each of these approaches, however, makes certain assumptions that
might be contested: (1) that death is more or less determinate, more
event-like than process-like, (2) that there is a uniquely correct
definition of death, which can be formulated in terms of necessary and
jointly sufficient conditions, and (3) that human death is morally a
very important marker. Now we will consider three nonstandard ways of
thinking about death, each of which directly challenges one of these
assumptions.
Each of the approaches considered so far asserts the correctness of a
single standard of death. Might different standards be appropriate for
different purposes? If so, then the debate characterized in previous
sections has reflected, to some extent, an exercise in futility: a
search that wrongly seeks a determinate event, which can be captured
by a single standard, rather than a process.
According to two authors who develop this line of reasoning, the
nearly simultaneous emergence of organ transplantation and mechanical
ventilators provoked three practical questions: (1) When may doctors
take organs for transplantation? (2) When may doctors unilaterally
discontinue treatment? (3) When is a patient dead for legal purposes
and appropriately transferred to an undertaker? (Halevy and Brody
1993). Rather than assuming that one standard for death will
adequately answer these three questions—a possibility rendered
doubtful by the interminable debate over standards—we should
answer each question on its merits, disaggregating death
accordingly.
Providing one example of how these practical questions might be
answered, the authors argue that organ procurement is appropriate when
the whole-brain standard has been met (apparently precluding DCD),
unilateral discontinuation of treatment is appropriate when the
higher-brain standard has been met, and a patient should legally count
as dead when traditional criteria have been met (ibid). (Here we need
not consider the authors' specific arguments for these
determinations.)
But why must each answer invoke a standard of death? An alternative
would be to adopt an updated traditional standard, which would supply
legal criteria for death, while denying that unilateral
discontinuation of treatment and organ procurement must await death.
To be sure, harvesting vital organs from living patients would require
an exception to the dead-donor rule, the social risks of which might
well be avoided if death were disaggregated along the lines suggested.
But the alternative possibility of separating death from particular
“death behaviors” motivates the question of whether there
are further grounds for disaggregating death into a process.
A possible further ground is the thesis that life and death, although
mutually exclusive states, are not exhaustive: “Although no
organism can fully belong to both sets [life and death], organisms can
be in many conditions (the very conditions that have created the
debates about death) during which they do not fully belong to either.
… Death is a fuzzy set,” (Brody 1999, 72). What are we to
think of this proposal?
It seems undeniable that the boundary between life and death is not
perfectly
sharp.
[
4
]
The specification of any
standard will require some arbitrary line-drawing. Operationalizing
the whole-brain standard requires a decision about which brain
functions are too trivial to count and need not be tested for. Making
a traditional standard clinically useful requires a cut-off point of
some number of minutes without heartbeat or respiration for the loss
of functioning to count as irreversible. A higher-brain approach needs
criteria for determining what sorts of brain damage constitute
irreversible loss of the capacity for consciousness and which count as
reversible. Yet, while some arbitrariness is inevitable, and
highlights a blurred boundary, the blurring in each instance concerns
very specific criteria and clinical tests for determining that a
standard has been met, not the standard itself. None of the blurred
boundaries just considered is inconsistent with the claim that some
standard is uniquely correct. Moreover, if essentialism regarding
human persons is true—that is, if we human persons have an
essence locating us in our most basic kind (e.g., animal, minded
being)—this would strengthen the case for a uniquely correct
standard by suggesting a foundation for one.
But we must consider the possibility that there is no correct
standard. Perhaps death is no more determinate than adulthood. Some
people are clearly adults and some people are clearly not adults. But,
as any college professor knows, many people are ambiguously
adults—mature enough to count as adults in some ways but not in
others. Socially and legally, we treat 16-year-olds as adults for
purposes of driving, 18-year-olds as adults for purposes of voting and
bearing the full weight of criminal law, 21-year-olds as adult enough
to drink alcoholic beverages, and so on. Nor is this disaggregation of
adulthood incoherent or even particularly awkward; rather, it seems to
fit the facts about the gradual development of maturity, acquisition
of experience, and accumulation of birthdays. Disaggregating death,
one might argue, would be similarly faithful to facts about the
frequently very gradual demise of human persons.
Even if this argument persuades us that death is more process-like
than event-like—and to do this it must persuade us that it is
death itself, not dying
, that is process-like—it does
not follow that we ought to draw several lines for the determination
of death. Consider the confusion that would likely result from such
statements as “Grandmother is partly dead, but less dead than
Grandfather, although he's not fully dead.” People are so
accustomed to thinking of life and death as mutually exclusive,
exhaustive sets that there would be considerable practical advantage
in insisting on some sensible line that demarcates death in this way.
It is true that disaggregating adulthood poses no insuperable
practical difficulties, but death is importantly different. For we
generally assume that one goes out of existence (at least in this
world) at death, a rather momentous change with—at least in the
status quo—far-reaching social and legal ramifications.
Confusion as a result of plural lines for death may be more troubling
and more likely, for the idea of someone's only partly existing is of
questionable intelligibility. On the other hand, a proponent of
disaggregating death might reply that (1) we could either reserve the
language of death for the traditional standard or get used to the
language of someone's being partially dead, and (2) we should
appreciate that existence
is
sometimes partial as in the case
of a half-assembled car.
Most discussions of the definition and determination of death assume
that there is a uniquely correct definition of death. Definitions,
classically understood, are supposed to state necessary and jointly
sufficient conditions for the correct application of a word or
concept. They may be thought to capture
de re
essences
existing independently of human thought, language, and interests, or
de dicto
essences determined solely by linguistic meaning.
The major approaches we have considered have tried both to define
death by capturing its essence and to advance a standard for
determining human death that coheres with the definition. But what if
the term “death” cannot be defined in any such way?
One might insist that death can be defined, as the competing
definitions demonstrate. But, of course, the trick is to define the
term adequately. For example, the organismic definition—death as
the irreversible cessation of functioning of the organism as a
whole—makes no reference to consciousness. Yet surely, one might
argue, any organism that maintains consciousness should count as alive
even if the organism as a whole has irreversibly ceased to function
(whether or not this possibility is merely theoretical). Definitions
associated with the higher-brain approach—such as human death as
the irreversible loss of mind—implausibly imply that a PVS
patient is dead despite exhibiting spontaneous breathing and
circulation, brainstem-mediated reflexes, and the like. The best
explanation for the shortcomings of leading efforts to define death,
the argument continues, is that death is not amenable to definition in
terms of necessary and sufficient conditions (Chiong 2005). Let's
consider two distinct ways this thesis might be developed.
First, one might argue that the concept of death exhibits only
“family resemblance” relations among its instances, as
Wittgenstein argued was the case for the concepts of
game
,
language
, and many others (Wittgenstein 1953). There are
various features of an organism that count towards its being dead, yet
there is no authoritative list of features all of which must be
satisfied for it to be dead. Each of the following, for example, seems
relevant: unconsciousness, absence of spontaneous efforts to breathe,
absence of heartbeat, inertness, lack of integrated bodily functions,
incapacity to grow, and physical decay. If all of these conditions are
present, an organism has surely died. But producing an authoritative
shortlist of necessary and sufficient conditions seems futile. One
scholar has advanced a parallel claim about the concept of life:
When some property is central to the cluster—as I've argued
consciousness is—then possessing only this one property may be
sufficient for membership in [the class of living things]. However,
merely possessing one or several properties that are peripheral to the
cluster may not be sufficient for membership. [S]ome robots are
organizationally complex and functionally responsive, though
intuitively not alive (Chiong 2005, 26).
Another direction in which to take the thesis that death is not
amenable to classical definition is to argue that death is a natural
kind whose essence may be obscure. Kripke influentially argued that
natural kinds—kinds determined by nature rather than by human
thinking, language, or interests—often resist adequate
definition because their essential features may be entirely unknown to
those referring to the kind in question (Kripke 1970). To define a
term by reference to the features people originally used to pick out
the kind in question won't do, because those features may be
accidental, not essential, and speakers may even be mistaken about
them. Those naming the kind
whale
might have thought whales
were the largest fish in the ocean, but whales are not fish and their
size relative to other creatures is a contingent matter. We can refer
meaningfully to whales, to the creatures picked out by the term
whale
(the name for the kind), without knowing the essential
features of whales, features likely to involve subtle biological
details. Perhaps death, too, is a natural kind whose essence is
obscure (a possibility entertained in Chiong 2005, 24–25). A
likely challenge to this argument is that we already know a great deal
about the physical processes involved in death, making it unlikely
that death has a hidden essence the failure to discover which impedes
adequate definition.
Importantly, though, one can claim that death is a natural kind
without accepting any kind of essentialism. An alternative to the
essentialist conception is the homeostatic property cluster theory of
natural kinds (Millikan 1999). On this view, natural kinds do not, or
at least need not, share essential properties. They are comprised by
members sharing a stable cluster of similarities, which are brought
about by “homeostatic causal mechanisms” (such as, in the
case of species, common developmental programs and selective
pressures). On this view, X (e.g., a fetus) might be a member of a
natural kind (e.g., our species) despite lacking one of the properties
(e.g., the potential for rationality) among the cluster of
similarities. Death and its opposite, life, might similarly be natural
kinds lacking essences, each kind being associated with a cluster of
properties that tend to go together and support one another without
being
necessarily
coinstantiated (see, e.g., Chiong 2005). If
so, death cannot be defined in a set of necessary and sufficient
conditions—in which case no such definition can justify a
particular standard.
If death has no essence and resists definition, what is the upshot?
One possible inference—that the boundaries of death are
vague—would partially merge this approach with the previous one,
which construed death as a process. We have noted that one response to
the claim of vague boundaries (the response favored in the previous
approach) is to embrace several lines, each for a different purpose,
in determining death. Another possibility is to understand the vague
boundaries as inviting discretion in the matter of producing a single
standard of death. So long as a particular standard does not have
clear and highly implausible implications, it is admissible for
consideration on this view. Society may then select, among admissible
standards, whichever is most attractive for practical purposes. It has
been argued, along these lines, that the higher-brain standard is
inadmissible for implying that those in PVS are dead while the
traditional cardiopulmonary standard is inadmissible for implying (in
principle) that a still-conscious individual might be dead, clearing
the ground for the whole-brain standard, which has no fatal
implications and is attractive from a practical standpoint (Chiong
2005).
Having already explored difficulties (and strengths) of each standard,
how might we evaluate the more general thesis that death is not
amenable to classical definition? One strategy open to critics of this
reasoning, of course, is to argue that some definition is adequate.
Another is to defend the disaggregation of death, as previously
discussed. A third strategy would be to argue that our failure thus
far to produce an adequate definition does not mean that none is
possible. Some concepts can be adequately captured by classical
definitions even if it is difficult to produce them. It would appear
premature, therefore, to render a judgment on the success of the
present approach to understanding human death.
A final assumption underlying the mainstream discussion of the
definition of death is that human death is a morally crucial marker.
Were it not, then accuracy in the definition of death would be of
purely ontological, conceptual, or scientific interest. This attitude,
of course, is not the prevailing one. Not only do we tend to regard
many behaviors as appropriate only if an individual has died; the
criminal law treats as momentous the question of whether one person
has killed—that is, caused the death of—another person,
even if such considerations as motive, deliberation, and special
circumstances are also important.
It is not difficult to see, though, how one might challenge this
presumption of death's moral salience. After all, we have already
begun to remove certain behaviors from the class of death behaviors.
For example, in many circumstances termination of life supports need
not await a patient's death. And, as we have noted, there are calls to
abandon the dead-donor rule in the context of organ transplantation.
We might go further in separating death from the cluster of moral
concerns traditionally associated with it. For example, without
embracing the higher-brain approach to death, we could hold that
irreversible loss of the capacity of consciousness entails a loss of
moral status
, at which point traditional death behaviors are
appropriate (Persson 2002). We might even overhaul the criminal law
with respect to killing:
It is then the irrevocable loss of the capacity for consciousness that
is the great loss; so it is for the causing of it that criminal law
should mete out the severest punishment. Killing, or the causing of
(biological) death, should be punished to this degree only if, as is
normally the case, it brings along the irrevocable loss of the
capacity for consciousness (ibid, 32).
One implication of this proposal is that harvesting organs from PVS
patients, thereby killing them, would not be punishable insofar as
these patients, having irrevocably lost the capacity for
consciousness, have already suffered “the great loss” and
no longer possess moral status. Some attracted to this approach will
want to argue further that the crime of murder is really that of
causing the irrevocable loss of the capacity for consciousness
without first obtaining voluntary, informed consent from the
person to be killed
. The
italicized qualification would create conceptual space for a
justification of active euthanasia (see the entry on
voluntary euthanasia
).
The present proposal to separate the issue of death from what is
morally important is somewhat radical. Yet its chief ground for doing
so, the claim that the capacity for consciousness is what underlies
moral status, cannot be dismissed. On the other hand, this claim
apparently relies on the thesis (which we considered in connection
with the higher-brain approach) that only what affects one's
experience can affect one's interests. As we saw, this thesis is far
from self-evident. For those who disagree with it, the time of
death—the time at which one no longer exists (at least in this
world)—is likely to retain some of the moral importance
traditionally accorded to it. Moreover, even if the philosophical case
for demoting the moral importance of death were airtight, we cannot
responsibly dismiss widely held sensibilities, including those at odds
with the present approach, in constructing public policies concerning
death. Certainly it is contestable to what extent the public could
embrace further demotion of the moral importance of death, and to what
extent its limited ability to do so matters for public policy.