Is "Pulling the Plug" Analogous to Abortion?

During the radio show on Sunday, Melinda tweeted a link
to a quote
from an article by Francis
Beckwith in response to this question from a caller (paraphrased): If it’s okay to pull the plug on a brain-dead patient
who is no longer sentient, why isn’t it equally okay to abort an unborn child who
isn’t sentient?  

Here’s what Beckwith has to say about the folly of basing
“personhood” on current or past sentience and why “pulling the plug” is not
analogous to abortion:

Some ethicists argue that the
unborn becomes fully human sometime after brain development has begun, when it
becomes sentient: capable of experiencing sensations such as pain. The
reason for choosing sentience as the criterion is that a being that cannot
experience anything (i.e., a presentient unborn entity) cannot be harmed. Of
course, if this position is correct, then the unborn becomes fully human
probably during the second trimester and at least by the third trimester.
Therefore, one does not violate anyone's rights when one aborts a nonsentient
unborn entity.

There are several problems with
this argument. First, it confuses harm with hurt and the experience of harm
with the reality of harm. One can be harmed without experiencing the hurt that
sometimes follows from that harm, and which we often mistake for the harm
itself. For example, a temporarily comatose person who is suffocated to death
"experiences no harm," but he is nevertheless harmed. Hence, one does
not have to experience harm, which is sometimes manifested in hurt, in
order to be truly harmed.

Second, if sentience is the
criterion of full humanness, then the reversibly comatose, the momentarily
unconscious, and the sleeping would all have to be declared nonpersons. Like
the presentient unborn, these individuals are all at the moment nonsentient
though they have the natural inherent capacity to be sentient. Yet to
countenance their executions would be morally reprehensible. Therefore, one
cannot countenance the execution of some unborn entities simply because they
are not currently sentient.

Someone may reply that while these
objections make important points, there is a problem of false analogy in the
second objection: the reversibly comatose, the momentarily unconscious, and the
sleeping once functioned as sentient beings, though they are now in a
temporary state of nonsentience. The presentient unborn, on the other hand,
were never sentient. Hence, one is fully human if one was sentient
"in the past" and will probably become sentient again in the future,
but this cannot be said of the presentient unborn. 

I need to highlight this part because it’s so key:

There are at least three problems
with this response. First, to claim that a person can be sentient, become
nonsentient, and then return to sentience is to assume there is some underlying
personal unity to this individual that enables us to say that the person who
has returned to sentience is the same person who was sentient prior to
becoming nonsentient. But this would mean that sentience is not a necessary
condition for personhood. (Neither is it a sufficient condition, for that
matter, since nonhuman animals are sentient.)

And now we get to the relevant difference between a brain-dead
patient and the unborn:

Consequently, it does not make
sense to say that a person comes into existence when sentience arises, but it
does make sense to say that a fully human entity is a person who has the
natural inherent capacity to give rise to sentience. A presentient unborn human
entity does have this capacity. Therefore, an ordinary unborn human
entity is a person, and hence, fully human.

Second, [A. Chadwick] Ray points
out that this attempt to exclude many of the unborn from the class of the fully
human is "ad hoc and counterintuitive." He asks us to
"consider the treatment of comatose patients. We would not discriminate
against one merely for rarely or never having been sentient in the past while
another otherwise comparable patient had been sentient....In such cases,
potential counts for everything."

Third, why should sentience
"in the past" be the decisive factor in deciding whether an entity is
fully human when the presentient human being "is one with a natural,
inherent capacity for performing personal acts?" Since we have already
seen that one does not have to experience harm in order to be harmed, it seems
more consistent with our moral sensibilities to assert that what makes it wrong
to kill the reversibly comatose, the sleeping, the momentarily unconscious, and
the presentient unborn is that they all possess the natural inherent capacity
to perform personal acts. And what makes it morally right to kill plants and to
pull the plug on the respirator-dependent brain dead, who were sentient
"in the past," is that their deaths cannot deprive them of their
natural inherent capacity to function as persons, since they do not possess
such a capacity.

(HT: Wintery
Knight)