[Today’s guest post by Timothy Hsiao is part of our paid blogging program.]
offered various laundry lists of criteria that all purport to list the
properties relevant to being a person, i.e. an intrinsically valuable
being worthy of moral concern and protection. One such proposal holds that the
possession of a brain or brain activity is a requirement for being a person. In
this post I’ll briefly sketch a few problems facing this position.
the brain requirement may be understood. First, we may take the brain criterion
to mean that having a brain is a necessary condition for being a person.
This means that although all persons must possess a brain, the mere possession
of a brain is not enough to confer personhood. Second, the brain criterion may be understood to mean that the possession of a brain is a sufficient
condition for being a person. This means that any being with a brain
qualifies as a person simply because it possess a brain. Third, the
brain criterion may state both a necessary and sufficient condition for
personhood, meaning that all persons must have brains and that the possession
of a brain is enough to qualify a being as a person.
faces difficulties. The claim that the possession of a brain is a necessary
condition for being a person seems false; for it would appear that there could
exist persons who lack a brain. There might, for all we know, exist aliens or
some other species that lack brains but who are nevertheless persons capable of
thinking rationally and acting freely. If this scenario is at least possible
– and it certainly seems like it is – then having a brain is not necessary for being
a person, for what this shows is that there is no conceptual connection between
the two. The brain may enable the expression of personhood by enabling
the expression of, say, the capacity to think rationally, but this function
need not be accomplished only by a brain.
well, one that also applies to the claim that the possession of a brain is sufficient
for personhood. Many insects and animals possess brains, but surely they aren’t
thereby rendered persons as well. The brain criterion will need to be modified
to state that a certain type of brain is necessary or sufficient for
personhood. But then what is doing the real work here is not the possession of
a brain, but the possession of a brain that possesses some other morally
relevant property. It is the possession of this property, not the brain,
that is relevant to personhood. But possession of this property is grounded in
the kind of organism that the being in question is, since the kind of organism
something is serves to determine the structure of its body parts. The brain is
only relevant to the expression of that property. Hence, pro-choice
philosophers are sometimes accused of confusing the property of being a
person with the property of functioning as a person.
doubt the adequacy of the brain criterion as relevant to personhood. Since the
third interpretation of the brain criterion presupposes the truth of the first
two, we may conclude that it fails as well.
philosophers might still insist that the brain surely is in some way relevant
to personhood. What gives the brain criterion its intuitive force is that the
brain is in a sense the “ruling part” of our bodies: it coordinates and directs
the development of the whole human being. Destruction of brain function leads
to the cessation of homeostasis, for the body is no longer coordinated as a
single unit. This is why the criterion for physical death has traditionally
been stated in terms of brain death.
as an argument against the personhood of the human embryo. Brain death is
accepted as a valid criterion of death by the medical community because brain
death signals the irreversible loss of human bodily functioning. When
the brain dies, organs are unable to work together for the good of the whole.
The various parts of the human being are no longer integrated as a single unit.
The exact opposite is true in the case of the developing human. Although adult
humans require a brain to integrate and direct their bodily functions, an
embryo’s development clearly does not require a brain to direct it. Their
law-like development occurs without the direction of the brain. It is only at a
later stage of development when the brain has developed sufficiently to take
over the direction of bodily functioning. Hence, the parallel with brain death
think that the brain criterion is neither necessary nor sufficient for being a