Chapter 2
The Terminus of the Self
In the previous chapter I developed
an account of the causal conditions necessary for continuation of the
self. In this chapter, starting from a
position of psychological reductionism, I want to view the question from a
different angle: At what point, or under
what conditions, do you cease to exist?
Looking at the question this way will yield some new and surprising
ideas. Given the earlier account of
psychological reductionism, I will not be detained for long defending a view of
death as termination of personality rather than critical damage to some or all
of the body.
Noting
an ambiguity in the idea of what it is to be dead will lead me to critically analyze the neocortical criterion
for death. The result of this line of
thinking will be a disjunctive criterion for death, allowing for the ambiguous
standard idea of death, but where one disjunct is a universally applicable
conception of death for persons. The
neocortical criterion will turn out to be, at best, adequate only for a
temporary stage in history. My universal
conception of death will both explain the contemporary plausibility of the
neocortical criterion and reveal its shortcomings if proposed as a permanently
valid criterion. After distinguishing
the ambiguous from the strict notion of death I will argue that we need a new
category
in addition to those of life and
death, that of deanimate. I will conclude by demonstrating that the new
category is practically important and not merely a theoretical curiosity.
Concepts
of and criteria for death have changed throughout history. A concept of death purports to tell us what
death is, while a criterion for the occurrence of death is the sign or signs by
which we determine that a person has reached a state of death. The traditional concept of death was left
vague until recently, its criteria involving cardiac and/or respiratory
function but without explicit distinction between criteria and concept. More recently, the concept underlying the
cardio-pulmonary criterion has been defined as the loss of integrated organic
functioning of the body.[1] In the current century there has been a
partial shift to a brain criterion, though this is usually added to the
cardio-pulmonary criterion rather than replacing it. Death is now often supposed to be determined
by the death of the whole brain, or the brainstem, which is responsible for
maintaining integrated organic functioning.
A
more recent proposal for a brain-criterion is the neocortical criterion.[2] As Karen Gervais argues, the neocortical
criterion marks a clear shift to a different concept of death. The
neocortical criterion (and, more controversially, other brain criteria) moves
us from a cardiac-centered to a consciousness-centered concept. According to this new definition of death, a
person is dead only when their capacity for conscious thought, for the
functioning and expression of their personality, has been lost. Defined this way, it will be clear that the
death of part or all of the body is only instrumental and not intrinsic to the
death of the person. I accept this new
conception of death and will analyze it further, but will modify the
neocortical criterion proposed by Gervais.
I will argue that this may not always be an adequate criterion even
today, and may frequently be insufficient in the reasonably foreseeable
future. The need for the category of
deanimate will emerge when I consider cases for which the neocortical criterion
is inadequate. Some of these cases will
be familiar from the personal identity literature.
Proponents
of the neocortical criterion and I agree that a proper understanding of death
requires a distinction between the human organism and the person. Death of the body or parts of the body
concern us only in so far as they bring about the death of our selves. Our selves die when we lose the capacity for
conscious thought, i.e., when we can no longer think, feel and express
emotions, have desires, form plans, and further our projects. I won’t argue this point further here, since
it surely follows straightforwardly from a psychological reductionist view of
the self and from my discussion, in Chapter 5, of intrinsic vs. instrumental
bodily continuity. The terminus of the
self, then, is the point at which the R-relation terminates.
An
initial example of how personal death can diverge from bodily death is in order
here: There are cases where a human body
is alive and functioning, meeting the criterion of integrated organic
functioning, but where the person is dead.
This is the situation in which the neurons of the higher brain have been
destroyed (neocortical death) thereby removing the possibility of conscious
thought, while the brainstem and perhaps the cerebellum, thalamus, and basal
ganglia continue to function along with the rest of the body.
Where
I differ from Gervais is in my understanding of the conditions essential for
the loss of the capacity for consciousness and personality. Gervais expresses her particular conception
this way: “[H]uman death, understood as
the death of a person, is a state in which the function of consciousness has
been irreversibly lost as a result of one of several possible combinations of
damage to the brain substratum” [150]. A
second statement contends that “[T]he individual’s essence consists in the
possession of a conscious, yet not necessarily continuous, mental life; if all
mental life ceases, the person ceases to exist; when the person ceases to
exist, the person has died” [157-58].
While I agree with these statements, I don’t think that they lead us to
a neocortical criterion for all cases.
This is because I understand the irreversible loss of the capacity for
consciousness to require the irretrievable loss of personal identity-critical
information, and this need not follow from irreversible loss of neocortical
function. I will explain this claim in
detail below, but will first try to head off possible confusion by exposing an
ambiguity in the meaning of ‘dead’.
Two Meanings of ‘Dead’
The
everyday concept of death, as well as some more refined theoretical concepts,
harbor an ambiguity. Failure to
recognize this ambiguity leads both to indeterminate concepts of death and
mistaken criteria for the occurrence of death.
Whether applied to a person or a biological organism as a whole, or to a
part, we can distinguish dead1 (functionally dead, non-functional) from dead2 (irreversibly
dead). Dead1 means “absence of function” and an assertion
that X is dead1 is equivalent to the denial that X is ‘alive’
or ‘living’. Life is a certain kind of
dynamic, functional process; if that process ceases then the entity is dead1. This is the straightforward sense in which
you might say “My car is dead,” or “My computer just died.” This has no implication that your car will
never work again. Perhaps a spark plug
needs replacing, or a connection to your computer’s power source is loose.
Dead
in the second sense, dead2, has a stronger implication:
It requires irreversible loss
of function. Suppose that at about the
time your car stops running you become rich.
You might decide to junk the car rather than have it repaired. You watch as your ex-vehicle is crushed into
a thin slab of metal. Now, if you
declare “My car is dead,” you mean that it is dead2, i.e., the same car cannot be
returned to you. There is not enough
left of the structure of the car to repair it and make it functional. At best, some of the metal could be used to
build a new car of the same model. But
that would a different car.
Since
most people are religious, the common conception of death has been influenced
by religious myths of an afterlife. This
is another source of ambiguity. The very
term ‘afterlife’ hints at the ambiguous notions of life and death inherent in
religious dogma. ‘Afterlife’ suggests a
time or place that is not life, yet neither is it death. In the Christian tradition, stories are told
of Jesus resurrecting the dead, and reincarnationists talk of people dying and
then being reincarnated. These examples
support the idea that the common notion of death, of being dead, is not
entirely a notion of irreversible cessation of consciousness. If religious people understood death as
irreversible loss of consciousness, they would describe paradigmatic cases of
death as continuing life in another form, and would deny that the person had
really died.
I
don’t want to rely too heavily on religious usage in making a case for the
ambiguity of the common concept of death.
We could rescue the religious notion (if not its users) from ambiguity
if we took statements such as “He’s dead” to mean only “He’s dead to this
world,” or “He’s physically dead, but truly lives on in Heaven.” On the other hand, most religious people have
not thought this through to the point of disambiguating their usage. To the extent that the meaning of a term is
determined by usage, the unreflective religious use of ‘death’ does contribute
to the ambiguity of the common conception of death. The concept’s use even by many non-religious
people will reflect the same ambiguity.
While the finality of death is reflected in the use of phrases like
“Dead and buried,” we also see pervasive use of the idea of people dying and
then being brought back to life, especially in fiction, whether it be
traditional tales such as Dracula, or recent movies such as Flatliners.
Dead2 – irreversible loss of function – is
synonymous with the final state of death.
Due to the contexts in which it is used, ‘death’ apparently lacks some
of the ambiguity inherent in ‘dead’.
Death has more of a ring of finality and irreversibility. Some thing, or part of a thing, can be dead1 but not have reached a state of death. When it is dead2 then we can also say that it has reached
death. Throughout this paper, when I use
the term dead without a qualifier I will mean dead2 – irreversibly or informationally
dead. In a later section I will propose
a term for dead1 so that the distinction will be clearly
reflected in the terms we use. This
distinction has been recognized by some writers on death, such as Byrne at al
(1979) who objects to brain-related criteria on the ground that loss of brain function is not synonymous with
destruction of the brain. While
destruction is irreversible, loss of function may sometimes be reversible:
There is no evident contradiction in supposing the existence of
permanent synaptic barriers, permanent analogs of botulinus toxin or morphine,
or yet other mechanisms that would block all brain-functioning while leaving
the brain’s neuronal structure intact and ready for action (at least until such
time as the effects of this non-function on the rest of the body might react
back on the brain in a destructive manner).
Therefore there is no reason to think that cessation of function, whether
reversible or irreversible, necessarily implies total or even partial
destruction of the brain; still less death of the person. [p.1987]
These two ideas have not always been
clearly separated. Distinguishing the
two senses of ‘dead’ will allow me to reveal a vagueness in the notion of
neocortical death. But I will argue that
even a clarified notion of neocortical death is inadequate, since it fails
essentially to mark the boundary of irreversible loss of personality. Supporting this claim requires a precise
explication of various types of continuity and of the relevant notion of
irreversible loss of continuity that will follow. First, I will reveal a second indeterminacy
in the usual notion of death, and distinguish this notion from my stricter, stipulative
notion of death. My claims about the
correct view of continuity in a condition of irreversibility will apply to the
stipulative definition, but not necessarily to the indeterminate notion.
Permanence vs. Irreversibility: Permanent and Theoretical Death
In addition to failing to distinguish
loss of function from irreversible loss of consciousness, standard conceptions
of death contain a further indeterminacy: A failure to disentangle the idea of
permanent absence or loss of consciousness from the idea of irreversible loss
of consciousness. Permanence and
irreversibility are distinct and separable since cessation of consciousness
might be permanent yet reversible. Every
day, patients are “no-coded” by doctors and declared dead. In no-coding a patient, the attending
physician is saying that though the patient could be resuscitated (by CPR or
defibrillation), this is not to be done, since the patient’s restored life will
be brief and unpleasant. Where a no-code
instruction has been issued, cardiac arrest entails permanent loss of
consciousness. Yet it might be quite
easy to resuscitate the patient, at least temporarily. Since the standard notion does not sharply
distinguish permanence and irreversibility, we can set out a disjunctive
conception of the occurrence of death:
Death of a person
occurs when
(a) Irreversibility condition: There is
a sufficient degree of destruction or dissolution of the brain (or other medium
for support of consciousness);
(b) Permanence condition: The capacity
for consciousness is lost and no attempt will ever be made to revive or repair
the patient.
We
need not hold that only the irreversibility condition is correct, although I
will argue that it is more fundamental.
Instead we can distinguish two senses of the term ‘death’ and give them
each labels. This will allow me to
provide a theory of the type of continuity necessarily involved in the
irreversibility condition while granting a role in the standard concept to the
permanence condition.
A person is theoretically dead if they meet the
irreversibility condition.
A person is permanently dead if they meet the
permanence condition, whether or not they also meet the irreversibility
condition.
Permanent
death occurs when a person is permanently lacking in consciousness. Such an assessment need not coincide with
irreversible loss of consciousness. In
many instances the two do not coincide, as in the no-coding case above, as well
as in more speculative cases such as biostasis.
Some individuals, following clinical death, have been placed into
biostasis (specifically) cryonic suspension in the belief that they might be
resuscitated in the future by more advanced medical technologies. Suppose that this procedure does preserve a
person sufficiently well, and that the necessary future repair technologies
will be developed. Now, suppose someone
had a heart attack and became clinically dead, i.e., their cardiac and
respiratory functions ceased, but the decision had been made not to place them
into biostasis. Then we could say,
immediately after the coronary, that the person had permanently lost
consciousness even though they had not lost consciousness irreversibly.
So,
there are a range of situations in which permanent and irreversible loss of
consciousness are not identical.
Permanent death is partly determined by the decisions we make and the
actions we perform. This means that
permanent death is not fully objective in the way that theoretical death is
objective (i.e., independent of decisions and actions). Irreversibility, in the sense I am using it,
refers to loss of the capacity for consciousness that cannot be reversed even
in principle. No matter how much
technology may advance, and no matter how different the medium for support of
consciousness may become (embodied in computers, for example), theoretical death
refers to a state beyond any possible capability to reverse.
Permanent
loss of the capacity for consciousness may appear to be an objective matter
also: Either someone will be returned to
consciousness at some point or they will not.
Our beliefs regarding the probability of resuscitation are subjective,
just as are our beliefs about reversibility, but surely the permanence of lack
of awareness is an objective matter? Not
if by ‘objective’ we mean “independent of human action and decision.” Suppose cardiac and respiratory function
cease in Smith. To an uninvolved third
party the permanence or lack of permanence may be a factual, objective
matter. Either Smith’s bodily functions
will restart spontaneously or they will not, and either someone else will
successfully intervene with CPR or defibrillation or they will not.
However,
from the point of view of someone in a position to medically intervene (call
her Robinson), the permanence of Smith’s condition cannot be regarded as
determined independently of the intervener’s decisions and actions. (This is assuming that intervention has a
more than zero probability of success, otherwise intervention is futile even if
Robinson believes otherwise.) Robinson
cannot regard her own actions as already determined; she has a genuine decision
to make. To Robinson then, if not to an
uninvolved observer, the permanence or transience of Smith’s loss of
consciousness is not fully objective.
The same point can be made using Byrne’s example above, in which the
brain’s capacity to function has been blocked.
In that case, the permanence of the condition may depend on the
decisions and actions of researchers and medical personnel to take steps to
reverse the condition. Finally, in the
cases of persons placed in biostasis for possible future repair and
resuscitation, the permanence or transience of their condition may depend on
the actions of those maintaining them in suspension, on researchers seeking to
develop repair technologies, and on legislators who may choose to prevent such
research or the revival of the biostatic persons.
Permanent
death and theoretical death both may involve a shift in our attitudes toward
the person. A belief in the person’s
permanent or irreversible loss means that we will no longer think of the person
interacting with us in the future, or having further experiences. We will no longer include them in our
plans. This shift in attitudes will be
reflected in our customs and in the law.
The rights and status of the deceased person will change: They can no longer be rewarded or punished,
cannot make contracts, and will not be considered in our plans for the
future. However, these attitudinal
changes are more closely tied to permanent than theoretical death since they
will occur once we have decided that absence of consciousness is permanent even
though we may know that consciousness could be restored. That is, attitudes will not shift if we do
not believe them to be permanently gone, but attitudes will shift if we believe
them to be permanently though not irreversibly gone. The fact of theoretical reversibility will
not affect our attitudes once we are certain that the theoretical possibility
will never be acted upon.
Irreversibility
has (or should have) priority over permanence in determining our
attitudes: An assessment of irreversible
loss of consciousness ought to lead us to an assessment of permanent loss of
consciousness. But the reverse is not
true; a belief in someone’s permanent lack of consciousness need not require us
to believe that they irreversibly lack consciousness. We would only believe “if permanently then
irreversibly nonconscious” if the two were identical in a particular instance,
as when a person’s brain is instantly destroyed. Since decisions to allow reversible cessation
of consciousness to continue should be founded on our beliefs about possible
reversibility of nonconsciousness, the reversibility condition is the more
fundamental to us as agents. This makes
it important to be very clear about the limits on reversibility. If we misunderstand these limits, and believe
loss of consciousness to be irreversible when it is not, then we risk acting,
or failing to act, in such a way that we cause someone to become permanently
dead unnecessarily (by burying or burning them rather then treating or
maintaining them).
Irreversible Cessation and Types of
Continuity
Having distinguished the permanence
and irreversibility conditions, I can now focus on the universally applicable
irreversibility condition. Various types
of irreversible cessation of consciousness might be thought essential to
theoretical death. I will argue that the
correct condition is irreversible loss of informational
continuity. In defending this condition
I will deny the universal applicability of the neocortical criterion, even if
it embodies the irreversibility condition rather than the permanence condition,
and even if it embodies destruction of the neocortex rather than loss of
function.
Gervais’ reason for proffering the
neocortical criterion for death is clear enough: “…destruction of the neocortex has been shown
to produce permanent unconsciousness and to be an empirically verifiable
pattern of brain destruction prior to the failure of the organism as a whole. Since human death is the death of the person,
and the death of the person occurs with permanent loss of consciousness,
neocortical death is an adequate criterion for declaring death” [150-51]. And, a few pages later: “[T]he individual’s essence consists in the
possession of a conscious, yet not necessarily continuous, mental life; if all
mental life ceases, the person ceases to exist; when the person ceases to
exist, the person has died. Upper brain
death destroys all capacity for a conscious mental life, and it is therefore
the death of the person.” (pp.157-58.) I
will agree that the neocortical criterion, when carefully stated, is an
adequate criterion for present day conditions, but will argue that it will not serve
as a universally valid criterion. To
establish this, I need to show that persons can continue to exist despite being
neocortically dead (in either sense). To
this end I will distinguish different types of continuity and evaluate their
relative importance for the continuation of the self.
Structural
Continuity: Atoms or molecules may
gradually be replaced, but the arrangement of the parts of the body or brain
persists. That is, the physical
structure is maintained even though there may be a gradual turnover in the
material of which it is composed.
Structural continuity is static when two temporal stages of the system
are qualitatively identical, and dynamic when the later stage has resulted from
the earlier stage by a sufficiently gradual process involving no spatiotemporal
discontinuity.
Functional Continuity: (a) Bodily functional continuity: The body and (perhaps) the brain continue to
function (either autonomously or with mechanical support). Functional continuity may be maintained
despite a serious loss of structural continuity. Replacement of the heart with a mechanical
heart may maintain the original function despite the two organs having entirely
different structures. (b) Psychological
functional continuity: Personality
continues to operate and act; consciousness (or the capacity for consciousness)
is maintained. This may occur despite a
radical change in the structure of the physical organ making consciousness
possible. Loss of functional continuity
may be (i) reversible or irreversible by current means, or (ii) reversible or
irreversible by any empirically possible future technology.
Informational
Continuity: Physical structure may
be destroyed, but all the information necessary potentially to allow
reconstruction of the brain (or other consciousness-support structure) and thus
restoration of its function persists.
The
neocortical criterion is not a universally applicable criterion of death. Gervais would probably agree with this, since
she is open to further refinements in our criteria,[3]
and she accepts that a person embodied in something other than a human body
could be the same person. As I will show
below, this means a person might survive the destruction of their brain. The neocortical criterion is merely a
normally reliable criterion—in 1995—for diagnosing death or for making a
prognosis of death (depending on whether neocortical death is taken to mean
loss of function or destruction). A
presumption of universal applicability would be acceptable if it were
impossible for a person to survive neocortical death. However this is not necessarily the
case. Whether we are to understand
“neocortically dead” to mean permanent loss of neocortical function or
destruction of the neocortex, selves may perdure regardless. I will examine both senses in which someone
might be said to be neocortically dead and show that neither are acceptable
criteria.
Loss of neocortical function: To say that someone is neocortically dead, or
that they have lost the capacity for consciousness, might mean that the
neocortex has ceased functioning and it cannot be restarted with available
technology; or it might mean that the neurons of the neocortex and their
patterns of interconnectivity have either decayed or been destroyed so that no
empirically possible future technology could repair them. Which of these Gervais is using is hard to
determine since she never actually gives her own definition of neocortical
death; she cites definitions found in the literature, without pointing out that
they are not equivalent. (She also
appears to use permanent cessation and irreversible cessation interchangeably.[4]) Two prominent definitions cited on pages
11-12 involve destruction of
neocortical or apallic neurons; but the definition quoted from J.B. Brierley
(p.13) is a function-based definition.
Brierley states that neocortical death “implies a persistently
isoelectric EEG and the absence of sensory evoked responses in the neocortex,
together with the resumption of spontaneous respiration and of certain
brainstem reflexes.”
Of course, given today’s standard practices, a
patient who is neocortically
non-functional will eventually become neocortically
destroyed, though this may take hours or days, even without cooling to slow
enzymatic degradation.[5] But this is no reason to conflate the two, as
Gervais clearly recognizes in the context of a parallel criticism of Lamb: Lamb claims that “the death of the brainstem
is the necessary and sufficient condition for the death of the brain as a
whole—and that brainstem death is therefore itself synonymous with the death of
the individual.” Gervais correctly argues against Lamb that “To say that the
loss of integration becomes irreversible is not to say that the loss has
occurred.” (Gervais, p.148) Irreversibility of a function that leads to brain
death is prognostic, not diagnostic of brain death. Now, under standard conditions (in the past
and present) cessation of neocortical function is prognostic of personal death,
but it is not diagnostic unless accompanied by neocortical destruction. If death is an irreversible state, then
cessation of neocortical function that is irreversible by current medical technology is no more the point at which death
occurs than was cessation of heart beat in the past. If we were to find a way of restoring a
“dead” (non-functional) neocortex to function, then we would have to say that
the person had not been dead.
So
long as the necessary neuronal structures persist we cannot say that the
capacity for consciousness is irreversibly gone. Cessation of neocortical function need not
imply loss of critical structure or information: Sufficient structural and chemical clues may
remain to allow restoration and revitalization of neocortical function and
neuronal interconnections. Full
structural continuity of the cells is unnecessary for the possibility of repair
of the neocortex since the desired structure and function of the neurons may be
inferred from residual chemical clues, or it may only be necessary to repair
membranes, open ion channels, restore synapses, or replace organelles such as
ribosomes.
An
objection might be raised to the effect that “capacity for a conscious, but not
necessarily continuous, mental life” means that the neocortex can support
consciousness given the appropriate stimuli and that these stimuli should be
defined in terms of current technology.
An analogy might be given as follows:[6] If we say that a car has the capacity to move
at 110mph, we mean that it is currently in a state such that, given appropriate
stimuli (such as gas, a foot on the accelerator, etc.) it will achieve
110mph. The objection claims that we do
not mean that the car could achieve 110mph given available technology, and we
do not mean that, given some empirically possible but non-actual technology,
the car could achieve 110mph. The
problem with the objection lies in the fuzziness of the terms ‘capacity’ and
‘appropriate stimuli.’ Does the car have
the capacity to move at 110mph if a wire has been loosened? In that case it does not have the capacity
immediately, given only the normal stimuli.
However, there is a perfectly reasonable sense in which it does have
such a capacity: The car has the
capacity to move at 110mph if we reconnect the wire. If someone were to say, before reconnecting
the wire, that the car could not go 110mph, the statement would be misleading
in that we might be led to think that this kind
of car does not have that capacity. The
car will not function normally without that repair, but so long as the repair
can be effected there is an important sense in which the car does have that
capacity.
Suppose
the car has suffered some form of damage to its components so that it cannot
move, and currently no way exists to replace or repair the components to
restore function. Further suppose that
the manufacturer tells you that they are working on a new repair process that
will restore function, a process that should be available a month from
now. We will probably want to say that
the car does not have the capacity to move at 110mph, but that it can
potentially regain that capacity. If we
say this, it follows that loss of (current) capacity to function does not imply
irreversible loss of function. If asked
whether our car is dead, in the sense that it can never function normally
again, we should reply in the negative.
The car analogy, then, supports rather than undermines the case for
basing a criterion for death on irreversible loss of capacity rather than currently irreversible loss of capacity.
In
the neocortical case, if Gervais’s criterion for death is loss of the capacity
for consciousness (due to loss of neocortical function), then we can see that
her criterion is not equivalent to the irreversible loss of the capacity for
consciousness. Loss of neocortical
function may be currently irreversible, just as loss of cardiac output once was
irreversible with existing technology, but death does not occur (at least)
until the neocortex has been destroyed, or degenerated beyond any empirically
possible means of repair. For Gervais to
deny this would also require her, contrary to her stated view, to claim someone
to be dead as soon as their heart has stopped beating (and consciousness has
been lost) if there is no available (or known) means of restoring cardiac
function. If the neocortical criterion
is to serve as an accurate criterion in the present, it must therefore be
interpreted as neocortical destruction rather than currently irreversible loss
of neocortical function. With this
condition specified, and with the exceptions discussed below (in the Deanimate
section), I can accept the neocortical criterion as an adequate criterion for
death in 1995 and the near future.
The period between cessation of
neocortical function and true neocortical death (loss of structure) might seem
to be of merely theoretical interest but of no contemporary practical
significance since we cannot now
restore neocortical function, just as pre-20th Century it might have been
claimed that there was no practical significance to the fact that a person with
a still heart was not yet dead. Such a
claim would be mistaken. Attending to
the difference between currently
irreversible loss of function and true neocortical death will encourage the
search for means of preventing neocortical decay by preserving the neocortex in
an unchanging state, and for means of repairing the neocortex and restoring its
function. (Again, see the section on
Deanimate below.)
Neocortical destruction: By neocortical death, Gervais might mean not
loss of function but decay or destruction of the neurons of the neocortex and
their patterns of interconnectivity so that no empirically possible future
technology could repair them. (This is
unlikely to be Gervais’ intended meaning, if we interpret “the capacity for consciousness” to mean that
consciousness can be restored with currently available means only.) This is less parochial than the loss of
function definition and is acceptable as a historically temporary criterion
(i.e. given current technology), but it still fails to provide a
transhistorical, universally applicable criterion. Locking the criterion of death into
neocortical destruction is mistaken since, as I have argued in earlier
chapters, our continuity is essentially psychological continuity and
connectedness – the R-relation – and not physical continuity. We might say that we are software and not
hardware;[7]
the psychological relations that are me are currently instantiated in this neocortex, but I am not essentially this neocortex nor even
(more controversially) any neocortex. We
can conceive of personal continuation despite neocortical death, and this may
even become technologically possible in the future. Here are a couple of ways in which
neocortical death and personal death could come apart:
Brain
Scanning and Replacement: Suppose that, at some time in the future, some
extremely powerful scanner were available, the descendants of today’s MRI, NMR,
PET, SQUID, SPECT and CAT scanners.
These scanners might be used to scan a brain so completely that the
resulting data specified the entire neuronal structure, including neuronal
interconnections, electrical charges, spiking potentials, and levels of all
neurotransmitters and hormones. Suppose
that your brain was then destroyed (or is destroyed layer by layer as the
scanner does its work). A new brain is
then built according to the information gathered from the scan, it is implanted
in the original body, and all necessary connections are restored. We should say that this brain is a new brain, for a brain is a physical
object and spatiotemporal continuity is a necessary condition for physical
objects. (If we were to destroy and
replace only a small fraction of the original brain at any one time we would
probably say that the same brain
remained throughout.)
Despite
the spatiotemporal discontinuity and the destruction of one brain and its
replacement by another, the same person remains throughout the procedure. Though there is an interval during which
there is no structural or functional continuity, there is always informational
continuity. The new brain is structured
the way it is, and functions the way it does, because of the structure and
function of the original brain. In terms
of the argument of Chapter 2, the same person persists through this procedure
according to the Wide Psychological Criterion.
(We need not go so far as the either of the Widest Psychological
Criteria to reach this conclusion since a causal connection is maintained
between the earlier and later brains.)
We may be puzzled by how to describe the condition of the person during
the interval between the destruction of their original brain and their revival
in the new brain. They are not dead, but
we may not want to say that they are alive. I will return to this issue in the next
section.
Uploading:
In the second kind of case, I can survive the loss of my brain even though it
is never replaced by another
biological brain. If what matters in my
survival is my psychological continuity, then I will continue to exist so long
as my consciousness, my psychological features, are maintained in hardware that
is functionally equivalent at the necessary level.[8] This hardware may be nonbiological, perhaps
an appropriately-configured parallel-processing computer constructed according
to the information gained from the destructive scanning of my brain. The transfer of a person’s consciousness from
their brain to a computer is referred to as “uploading” and has been described
both in fiction and nonfiction.[9] This informationalist conception of personal
continuity is expressed by Daniel Dennett:
If you think of yourself as a center of narrative gravity, on
the other hand, your existence depends on the persistence of that narrative
(rather like the Thousand and One Arabian Nights, but all a single tale), which
could theoretically survive indefinitely many switches of medium, be teleported
as readily (in principle) as the evening news, and stored indefinitely as sheer
information. If what you are is that
organization of information that has structured your body’s control system (or,
to put it in its more usual provocative form, if what you are is the program
that runs on your brain’s computer), then you could in principle survive the
death of your body as intact as a program that can survive the destruction of
the computer on which it was created and first run. [Dennett (1991) p.430]
In
the brain scanning and replacement and uploading cases the later person-stage
is psychologically continuous with the earlier person-stage. If personal continuity is psychological
continuity then we cannot say, in these cases, that someone has died and been
replaced by another person. The very
same person remains throughout, despite the discarding of the hardware that
previously embodied their capacity for consciousness. To someone who wasn’t aware that our subject
had received a new brain, or had a silicon or optical brain-replacement in
their skull, no difference would be detectable, making it absurd to think that
the original person had died. I will not
belabor this point, having already set out my view regarding continuity in the
previous chapter.
We have seen that a person is not
dead immediately following cessation of whole brain or neocortical
function. Now I will argue that a person
is not properly described as dead, at least in the theoretical sense, while
they are incapable of consciousness but where their brain (or replacement
hardware) retains the structure allowing possible restoration of that
capacity. Going a step further, I will
show that a person is not dead while they exist only in the form of information
lacking a functioning embodiment. Though
they are not dead, we may not be comfortable describing them as alive.
Indeed, it would be inaccurate to describe them as alive. We need a new category to describe these
cases – that of deanimate; I will
divide this category into the subcategories deteriorating,
biostatic and inactivate.
On
the theoretical view, and more ambiguously on the standard view, absence of
life is not co-extensive with death. We
can see this by attending to the differing ideas of continuity defined above
and by a better understanding of the nature of life and death. By ‘death’ I mean the end point of the
gradual dissolution of a living system.
Dying is the process that takes an organism from life to death, from a process of living to a state of death. We should reserve the term ‘death’ for the result of the process of dying,
otherwise we will have no term to make that reference. If we were to say that death had claimed someone
as soon as their heart stopped beating, or their brain ceased functioning, we
would no longer be able to clearly differentiate very different conditions -
those of various kinds of biological and neurological cessation of function
from those of loss of any present or future possibilities for restoring
function. Death is therefore the state a
person is in when they are theoretically dead.
Almost
no one seems to willing to venture a definition of life. According to Prigogine and Stengers,[10]
a living organism is an open system in which matter and energy are exchanged
with the environment. A living organism
is a dissipative structure: a dynamic state of matter which originates in
far-from equilibrium conditions and involves a close association between order
and structure on one hand and dissipation or waste on the other. Living creatures keep internal entropy at
bay.[11]
When they fail to do this they cease coherent functioning and proceed down the
necrotic path of increasing dissolution.
Death is the end result of this entropic process. This dying process may be arrested and
reversed at some stages; how far along the process arrest and reversal can be
achieved depends both on how much critical information remains or can be
reconstructed and on the level of technology.
Since
there is a large gap between cessation of function (whether cardiac or
neurological) and loss of all structure and structure-critical information, we
need a term to refer to that part of the spectrum in which the person
potentially is fully or mostly recoverable.[12]
Deanimate can fulfill this need. It connotes absence of movement, cessation of
life, leaving us the term “dead” (in our theoretical sense) to exclusively
refer to an organism that has reached a state of death, without connoting
further decay. When someone’s heart
stops beating, or their brainstem ceases to integrate bodily functions, that
person becomes deanimate. They lose
consciousness and cannot spontaneously recover.
When they become deanimate, the dying process will continue until they
are dead, unless other persons intervene.
Such intervention may consist of cardiopulmonary resuscitation, if
deanimation has occurred in the last few seconds up to something under an hour,[13]
or it may take the form of biostasis (cryonics, vitrification, or advanced
suspended animation).
In
the case of biostasis, the deanimate person’s physical embodiment is
stabilized, by locking their constituent molecules in place at extremely low
temperatures or by chemical fixation.
Biostasis is thus a sub-category of deanimate; biostatic persons are
deanimate persons whose dissolution has been arrested (before reaching a
critical stage). If the technology
becomes available to repair the life-threatening condition causing deanimation,
and to reverse the changes caused by the biostasis technique (which may itself
add further injury), the biostatic-deanimate person may be restored to life.
Both
biostatic and inactivate fall under the category of deanimate but they may
usefully be distinguished. In the
previous section I described a hypothetical scanning procedure that gathers
thorough structural information about the brain. This information might be stored on an
inactive, non-biological medium for a period prior to reembodiment of the
information in a working brain. In that
case, the person would be deanimate and inactivate but not biostatic. Inactivate persons will be thought of as further
from being alive than will biostatic persons.
There are two related reasons for this:
First, while both biostatic and inactivate persons lack the capacity for
consciousness, the former exist in their standard embodiment, though in static
form. But inactivate persons persist
only as information instantiated in a form radically different from that of
their standard body. Technology capable
of resuscitating biostatic individuals probably is less remote than technology
capable of re-embodying an individual from their identity-critical information. Second, these differences in form and
temporal remoteness are likely to generate differing attitudes in us. On the permanence view of death, we are more
likely to regard an inactivate person as dead than a biostatic person. We will find it harder to regard someone as
not dead who persists only as nonbiologically-embodied information, and whose
revival we think only remotely likely.
This different makes it worthwhile distinguishing biostatic from
inactivate within the general category of deanimate.
We
can apply the category of deanimate on both the theoretical or the permanence
views of death, though its extension will differ between the two. On the theoretical view, when a person ceases
living and loses the spontaneous capacity for consciousness, they become
deanimate. They will continue to die
until they are dead, unless they are put into biostasis or otherwise
preserved. So, on this view the person
is first alive, then deanimate and degenerating, then deanimate and static, and
later, possibly, alive again. The
permanence view differs in that when life ends, if we believe the person will
never be returned to life, then we will say that the person goes immediately
from being alive to being dead. This
allows no room for a period describable as deanimate. The permanence view will agree with the
theoretical view in allowing for a period of deanimation only where we believe
that the person will eventually be restored to life. So, deanimation is compatible with the
permanence view but only where cessation of life is thought to be temporary.
For
some, it will be difficult to shake the feeling that someone who remains only
as inactively stored information is dead.
I think the feeling of oddness felt by some in thinking of an inactivate
person as not dead is largely generated by the entrenched standard belief that
not-dead = alive. Since an inactivate
person, even more than a biostatic person, is far from alive, the temptation to
think of them as dead can be strong. The
feeling of oddness should be dispelled by keeping the third category of
deanimate in mind. With that category in
place, it will seem even more odd to think of inactivate persons as dead. Inactivate persons and dead (ex-) persons
differ in important ways. In the former
case, a great deal about the living person is being preserved; all the
information specifying their psychology and its physical embodiment persists,
and ex hypothesi that information
could eventually be used to restore the person to life. All the knowledge and experience of the
original person remains, though as potentiality rather than actuality. The fact that the person experiences a break
in continuity of consciousness is not a reason to say that they died and
will be replaced by a different person
if the information is re-embodied. If we
were to say this, we would also have to say that persons who go into a coma and
later are revived have died and been replaced.
Why
not think of the situation as the person’s death and replacement? First, we need to remember that if we believe
someone to be inactivate it means that we believe it to be empirically
possible, now or in the future, to restore them to consciousness. Regarding them as dead has a number of
effects: We will cease to think of them
as involved in our lives in the future.
We will make no efforts to return them to life, instead treating their
inactivate form as equivalent to the ashes of cremation. We will withdraw all their rights and
disregard their interests in continuing life in the future. The pre-inactivate person may have made plans
for the post-reactivation stage of their life, but our regarding them as dead
will destroy their plans far more completely than if someone were to destroy
all of another person’s assets. There is
no obvious difference between treating an inactivate person this way and
disconnecting a comatose patient from life support when it is believed that
they could be brought out of the coma with treatments to become available in
the future.
If
we believe that the inactivate person will never be restored to life, perhaps
because they did not provide the funding to do so and no one else will be
willing to bear the expense, then we will correctly regard the person as
permanently dead, even though their condition is potentially reversible and so
they are not theoretically dead. This
kind of situation helps to explain intuitions to the effect that inactivate
persons are dead. Inactivate persons who
will never again be alive can indeed be regarded as dead – as permanently but
not theoretically dead. Maintaining the
distinction between the theoretical/reversible and permanence conditions will
distinguish the two classes of inactivate persons, those who are dead in the
permanent sense and those who are not dead in either sense, and thereby helps
dissolve any intuitions about the deadness of inactivate persons as a class.
Partial Death
Although the concept of death has
now been defined more precisely by distinguishing it from deanimation, an
indeterminacy remains due to the psychological reductionist theory underlying
these distinctions. We may expect it
always to be simple to tell when someone is dead, at least in principle. If death is put in the context of
psychological reductionism, this clarity evaporates as soon as we realize that
such continuity is a matter of degree.
The R-relation includes both psychological continuity and
connectedness. The same person continues
only if a person-stage has enough psychological connections to the preceding
person-stage. There is psychological
continuity between person-stages, i.e., the person survives, if those stages
are strongly connected. Parfit
stipulates that strong connectedness requires the persistence of at least 50%
of the usual number of psychological connections over the course of a day.
However,
as Parfit notes, this limit is entirely arbitrary, adopted only for the sake of
convenience. We could just as easily
claim that 60% connectedness over a day (or a week) meant that the original
person has been destroyed and replaced by a new person. The fact is that the previous person-stage
has 60% survived over the specified interval.
Beyond that fact it is a matter of decision and linguistic convention
whether we say the same person continues, or whether the original person
retains their identity. Our decision
will be influenced by the personal, legal, and cultural consequences of placing
the strong connectedness requirement at a particular level. This indeterminacy is worsened by the
problems involved in trying to weigh the relative contributions of different
components of psychological connectedness.
Are memories more or less important than skills? Are dispositions more
or less important than intentions?[14] Exactly what kinds and degrees of
psychological changes would add up to a 40% or 50% reduction in connectedness?
We
can accurately say that someone – some person-stage – suffering significant
brain damage has partly died. This is
just to say that the remaining person-stage has a significantly reduced degree
of psychological connectedness with the previous person-stage associated with
that body. Speaking of a person’s
partial death is not merely a manner of speaking; it is a reflection of a real
weakening in the strands that constitute the continuity of the person. The more of these strands that are removed at
a time, the less of the pre-existing person who continues. We may usefully think of a person’s survival
or continuity this way: If my friend
came out of a car accident with brain damage resulting in loss of some of his
personality or with alteration in personality, I would mourn for the loss of part
of the person he was. I would miss the
person-stage whom I knew and would have to acquaint myself with the new
person-stage. At the same time, I am
sorry for what has happened to my friend, the same person who continues to
exist. So long as the damage done to him
does not exceed the critical threshold beyond which strong psychological
connectedness is lost (wherever we set that threshold) he is the same person,
not qualitatively, but in the logical sense of personal identity. The same person persists, though a new
person-stage has peremptorily replaced the former stage of the person.
Though
we can think of death as a matter of degree, the legal system is not good at
handling spectra. The law regards
persons as either dead or alive – or at least alive or dead or deanimate – just
as it regards people as either above or below an age of consent. It may therefore be practically necessary to
decide on an line – arbitrary within broad limits – sorting cases of damage to
a person that result in their death from those that do not. If someone is too damaged then, although their body may continue to function and
some behaviors or responses may persist, we can say that the person has died,
changing their legal status, and setting in motion activities such as disposal
of the body and distribution of the estate.
(The body would not be disposed of if the person to whom it had belonged
had signed a living will directing that their body be maintained in such a
situation, and had provided funding for this purpose.) A plausible candidate for the standard of
being too damaged is the point (or
range) where someone loses the characteristics of personhood. These characteristics include the capacity
for consciousness and self-awareness, rationality, responsibility, and an
ability to communicate. These
characteristics are, to be sure, a matter of degree, but there will be some
cases where it is clear that personhood has been lost.
Let
us imagine a man, Jones, who is a normal, adult human being, possessing all the
familiar characteristics of personhood, displaying a robust intelligence, and
enjoying diverse relationships. One
unfortunate day, Jones is involved in a serious auto accident. His friends and family, gathering at the
hospital, are told that Jones has suffered a devastating head injury, but that
he will live. However, though he
breathes unaided and shows some awareness of the environment – moving away from
loud noises and towards the smell of food – he cannot recognize anyone. Despite repeated attempts no one is able to
evoke any sign of recognition from him.
Let us call this individual Jones-B, and the pre-accident person
Jones-A. Jones-B has not only lost his
memories of Jones-A’s life, he displays none of Jones-A’s wittiness,
insightfulness, ability to form complex and satisfying relationships, nor can
he even carry out a conversation. His
brain has been damaged to such an extent that he has to be fed, he does not
recognize friends and relatives of the past, and he cannot engage in any of the
activities that Jones-A could. On any
remotely plausible measure of connectedness, the remaining psychological links
between Jones-B and Jones-A are too tenuous to amount to strong connectedness:
Jones-A and Jones-B are not psychologically continuous. I hold that Jones-B is not the same person as
Jones-A; the two together do not form one longer lived individual, though they
consecutively share a single continuous body; Jones-A no longer exists; Jones-A
is dead.
In
cases like that of Jones, we can say that a normal person, who is suddenly
damaged so badly that they lose the qualities of personhood, ceases to
exist. The massive and discontinuous loss of psychological
connectedness means that personal continuity has been broken, and that person’s
life has been terminated. If the damage
is less, we will say that the same person lives on, though diminished, even if
many of their memories are gone, their personality undergoes some changes, and
their cognitive and communicative abilities are lessened. The point here is not that personhood is
essential to a person’s remaining alive; personhood is simply a plausible
marker for the minimum retention of connectedness required for a person’s
survival. My underlying claim, based on
psychological reductionism, is that death of a person necessarily results from
an excessive severing of connectedness; it is not that loss of personhood necessarily results in the death of a
human in all cases. We can see the
distinctness of these claims by considering a different kind of case.
Smith
is a healthy woman, her cognitive and communicative abilities, her capacity to
form relationships, and her ability to reason and to take responsibility being
comparable to those of Jones-A in my former example. Smith starts off in a condition much like
that of Jones-A, and she ends up as diminished as Jones-B, but she goes from
one state to the other differently.
Whereas Jones-A was replaced discontinuously and immediately by Jones-B,
Smith undergoes a gradual, years-long deterioration resulting from (let us
posit) the growth of inoperable cancer in her brain. Comparing Smith at an advanced stage of her
deterioration with her former healthy self, we see few psychological
connections – as few as connected Jones-A and Jones-B. Smith differs from Jones in that at no time
do we find a discontinuity remotely like that resulting from Jones’
accident. Comparing her condition
between any two adjacent days, or even months, we find only minor changes. Month by month her memories slowly fade, her
concentration weakens and dissolves, her confusion increases, and her capacity
to reason, communicate, and engage in complex behavior attenuates. Since Smith’s loss of connectedness is
cumulative rather than acute, psychological continuity is maintained. Even though the deterioration eventually robs
her of the characteristics of personhood, the gradualness of the loss means
that, unlike Jones-A, she has not perished.
As
it stands, the law holds that a person, after falling below the threshold for
personhood, has not died regardless of whether this occurred gradually or
discontinuously. Despite her defense of
the neocortical criterion, Gervais appears to agree with the current legal
view. According to
Gervais, a person (and not just a biological organism) continues to exist –
personal identity is maintained – despite total loss of personality, so long as
the capacity for consciousness remains.
We can agree in Smith’s case, where I also hold that Smith survives past
the loss of personhood. We can also
agree in the case of Jones-B; though not a person, Jones-B possesses a capacity
for consciousness of a limited kind and survives so long as that
continues. However, we differ in the
case of Jones-A where, according to Gervais, Jones-A continues to live after
the accident (being identical with Jones-B).
In
criticizing the view of Green and Wikler who, like me, employ a psychological
continuity conception of death, Gervais raises anencephalic infants as
supposedly being a problem. Gervais
thinks that the cases of anencephalic infants and cases like Jones should be
treated alike: “If the anencephalic are
obviously not dead, then Jones is obviously not dead either.” [140] If Jones, lacking sufficient neocortical
function to support personhood, is dead even though he has a living body, then
a baby born without neocortical function must also be dead.
Having
distinguished Gervais’ Jones into two individuals, Jones-A and Jones-B, my
response to Gervais is unproblematic: It is true that the anencephalic are
obviously not dead. But neither is
Jones-B dead. On the psychological
continuity view, Jones-A is dead, but there now exists a distinct individual,
Jones-B, who lives. Jones-A, in losing
personhood, lost so much connectedness that he ceased to exist. His body lived on, forming, along with the
remaining mentality, the new individual, Jones-B. Jones-B has suffered no loss of
connectedness, and so is clearly alive.
His case is therefore parallel with that of anencephalic infants, for
they – born without the capacity for consciousness – have never lost
connectedness.
In
considering a possible response to her objection from Green and Wikler, Gervais
complains that granting that the anencephalic baby is alive while the
brain-damaged ex-person is dead will lead to two identity criteria: “In the
anencephalic case, identity criteria and conditions of life and existence do
not overlap. It is confusing to speak of
alive bodies and dead persons, since a similar distinction could be drawn
across the board, even in brain-death cases.” (141) Her response is unconvincing; I see no reason
not to make a similar distinction
across the board, including brain-death cases.
Refraining from distinguishing conditions for life and death of bodies
and persons, Gervais will be forced to say that someone survives even if
practically everything that made them who they were is destroyed. She will have to claim that the bare capacity
for consciousness is most of what makes someone who they are. Furthermore, Gervais’ charge of inconsistency
against Green and Wikler can be applied to her own position because her own
criterion of upper brain death makes it possible to talk of alive bodies and
dead persons. In attacking the
whole-brain death criterion, Gervais made it clear that a person dies along
with their upper brain, even if the lower brain continues to maintain the body.
When should a declaration of deanimation be made? A person should be
declared deanimate (or be said to have deanimated) when it is judged impossible
or pointless[15]
to revive them given the available medical technology; that is, when conscious
activity: (i) has ceased, (ii) will not restart spontaneously, and (iii) cannot
immediately be restored artificially.
The third condition is optional: I include it because if the capacity
for consciousness can (and will) be restored immediately (e.g., by
defibrillation) probably we will want to regard them as alive rather than
deanimate in order to maintain all their rights as living persons. We could refer to persons who meet the first
two conditions, but not the third, as dormant. Deanimation might be declared on the same
grounds that death is now declared:
Cardiac and respiratory arrest, or lower brainstem dysfunction or
destruction, or loss of neocortical function.
When
should a declaration of death be
made? An individual will be theoretically dead and can be so declared if their
neocortex has been destroyed. On the
theoretical view, death should not be declared on cessation of cardiac or
respiratory function, nor upon brain dysfunction. However, though irreversibility provides a
deeper criterion of death, the permanence view may better suited to declaring death. A declaration of death is as much a legal and
social act as a medical act, marking a point where our attitudes toward the
person shift. We will no longer expect
to see them again; we will not think of them acting and living in the future;
we will not make plans for them; we will no longer take into account their
interests (except residual interests in the disposition of their former
property).
The
patient might be declared dead when heart-beat and respiration or brain
functions cease. A declaration of death
would then mean that the (theoretically) deanimate person was to be allowed to
continue moving toward death without intervention. This would amount to a declaration that those
involved regard the person as having permanently lost consciousness even if
they are not irreversibly nonconscious.
The patient may have stated that they wish to be regarded as dead when
they deanimate, either because they believe their reanimated quality of life
will be unacceptable, or because they believe that reversal of their
deanimation is not now and never will be possible.
Practical Importance of the
Deanimation Category
Embodying the category of deanimate
in the law would have several beneficial results. Recognizing the category of deanimate
persons, and the potential for expanding that category, would spur research in
neocortical preservation and repair. Common
practice would gradually move from disposal and dissolution of persons when
they are not theoretically dead to a situation where the possibilities for
maintenance and revival were affirmed and acted upon.
Understanding
the difference between deanimate and dead will help us to clarify the moral
status of comatose persons. I cannot
examine this issue here, except to note that the differential condition of
deanimate and dead persons should be accompanied by differing rights and
obligations. Deanimate persons should
have rights more extensive than dead persons but weaker than those of living
persons. When a person deanimates, they
will lose rights which depend on awareness, such as being bound by new
contracts, but will maintain rights against being harmed in various ways
(including being killed), and some control over their finances (through agents
chosen pre-deanimation or else appointed post-deanimation).
As
matters stand now, families suffer distress and heavy costs because persons who
are either truly dead or else irretrievable with current techniques must be
maintained on life support equipment. On
the informational criterion for death, more patients will be recognized as dead
and so released from pointless support.
In addition, some of those who would not be dead on the new criterion
could be disconnected from life support in order to place them in biostasis
instead of leaving them on a downward spiral.
Setting conditions for transferring patients from mechanical functional
support to stable biostasis is already needed due to the practice of cryonics
and would be facilitated by a broader understanding of the deanimate/dead
distinction.
Law
and medical practice should allow a patient to be declared deanimate before the
patient is fully brain dead (or neocortically dead), in order to allow
biostatic preservation of the brain in good condition. This will give the patient more choice over
what happens to them: Estimates of the possibility, probability, and
desirability of eventual reanimation will vary greatly between persons. Recognizing this as rightfully the patient’s
choice (perhaps with consultation) would be another benefit of introducing the
category of deanimate.
Glossary
Apallic Syndrome: Essentially the same as neocortical
death. Results from destruction of the
pallium, that is, the neocortical structures of the cerebrum.
Biostasis: Similar to the older term “suspended
animation.” A state in which a patient
is maintained without biological activity, thereby preventing decay. Currently this is practiced in the
unperfected form of cryonic suspension, in which the patient is frozen and
stored at -196C. Biostasis might take at least two other
forms: Vitrification, in which low-temperature storage is achieved without ice
crystallization; or chemical methods for locking all reactive molecules into
place.
Brain Death: Death of the entire brain. (Taken to be indicated by either a flat EEG
or lack of cerebral blood flow.)
Dead-1: Synonymous with “deanimate.” Not currently functioning (in the manner
appropriate to that kind of entity), as in “my car is dead.”
Dead-2: Permanently non-functional. This second sense is synonymous with death.
Deanimate: Synonymous with dead-1. The absence of function critical to
maintenance of consciousness. Includes
persons who are “clinically dead” and deteriorating, persons in biostasis, and
persons who are inactivate.
Death: The final destination of the dying
process. A state in which nothing actual
or potential remains of the person. The
death of the person may occur before or after the death of the person’s body or
brain.
Dormant: A state in which the capacity for consciousness persists (the neo-cortex is intact) and
where the body and lower brainstem are functioning but there is no
consciousness. (As in certain kinds of
coma, where administration of a drug can restore the person to consciousness.)
Dying: A process leading from deanimation to death.
Inactivate: Stable persistence of identity-critical
structure or information in the absence of life functions. While biostasis preserves a person’s original
physical form in a static state, being inactivate involves someone persisting
in the form of stored information specifying the structure of the person’s body
(or just their brain) without that body persisting.
Neocortical Death: Destruction or (currently) irreversible
cessation of function of the higher brainstem, so that the capacity for
consciousness is terminated. Deep
structures of the cerebral hemispheres such as the thalamus and basal ganglia
may be intact, in addition to the cerebellum.
Neocortically dead individuals may open their eyes periodically, show
sleep-wake periods, yawning, chewing or spontaneous swallowing.
Persistent Vegetative
State: The permanent absence of
consciousness. Neocortical death is one
criterion for this. (Also called
“persistent noncognitive state.”)
Permanent Death: Permanent absence of consciousness, whether
or not the person could be returned to consciousness.
Theoretical Death: Irreversible absence of consciousness.
[1]For
instance, Lamb (1985).
[2]See
Gervais (1986).
[3]See
p.182. However, she seems to be thinking
of these only as refinements resulting from a better understanding of the
neurological causes of persistent vegetative states and so is still tieing
personal death to some form of brain death criterion.
[4]See,
for example, p.159, lines 3-4 and line14.
[5]Studies
have shown that dopamine uptake by synaptosomes could still achieve 55% of the
values of fresh brains even 24 hours after “death.” Schwarcz (1981) subjected rat brains to
post-mortem conditions comparable to those typically experienced by
humans: Four hours of room temperature
followed by 24 hours at 4 C followed by brain isolation
and freezing of brain regions by placement in a -80 C freezer for five days. Glutamate uptake by striatal synaptosomes
prepared from striata frozen this way amounted to 26% of control uptake by
fresh tissue synaptosomes. Morrison and
Griffith (1981) isolated undegraded messenger RNA from human brains after 4 or
16 hours of death, with or without freezing in liquid nitrogen. The mRNA was used to direct protein synthesis
in vitro. Normal protein populations were
observed, leading them to conclude “that post-mortem storage for 4 to 16 hours
at room temperature had little effect on the spectrum of isolated mRNAs.” There are many such reports to be found in
the literature. A final example: Tower at all. (1973a), (1973b), (1976) showed
preservation of oxygen consumption and enzyme activities in brains of many
species, including whales subject to many hours of warm ischemia, after
isolation from the dead animal and freezing.
[6]This
objection was raised by Kadri Vivhelin.
[7]Though
this shouldn’t be taken to imply any simple two-level view. At one level we might say that a
psychological function is software written in a language of thought where the
hardware is a region of the brain. At a
deeper level the the functioning of the brain region could be described as
software and the hardware identified as the neurons composing the region. Deeper again, the individual neurons could be
functionally described, with the hardware level being identified with
organelles, membranes, neurotransmitters, and so on. See William G. Lycan's discussion of “The
Continuity of Levels of Nature” in Lycan (1987).
[8]A
behaviorist will say that a machine that behaves just as I would is thereby
functionally equivalent at the appropriate level. This is the methodological assumption behind
the Turing Test for machine consciousness or intelligence. Others who think about the possibility of
uploading consciousness or building conscious machines hold that the hardware
must be isomorphic to ours at some deeper level. Some will argue that a serial
processor is sufficient because any parallel processor can be implemented in a
Turing-equivalent serial processor.
Others hold that some degree of parallelism will be necessary to produce
genuine consciousness, intentionality, or qualia.
[9]See
Dyson (1988), Moravec (1988) and the SF novel by Rucker (1982). Uploading cases have been used in the
philosophical literature: See, for
example, the machine tape case in Veatch (1975), which reappears in Gervais
(1986) and Green and Wikler (1980).
[10]Prigogine
and Stengers (1984). Dawkins (1976, 2nd
ed. 1989).
[11]This
characteristic may be shared by non-biological entities, or “artificial
life.” A-Life researchers therefore
suggest that we understand life in terms of certain formal characteristics
rather than as essentially carbon-based chemistry. This way of conceiving of life clearly accords
with functionalist views of mental states.
For an overview of current work in A-Life see Kelly (1991).
[12]See
next section for cases where someone might be said to be partially dead.
[13]The
3-5 minutes rule for “brain-death” is no longer an impenetrable barrier. People have been recovered from many minutes
of ischemia at low temperatures with the help of calcium channel blocking
drugs.
[14]I
will discuss this issue in Chapter 6.
[15]Pointless
because, if revived, they would live only in great pain or with severe
disability, or would deanimate again within minutes, hours or days. A decision not to revive a temporarily
revivable patient is “no-coding.”
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