23 September 2009

Metaphysics: Personhood

The Objectivist
Problems with Persons
Dunkirk-Fredonia Observer
September 21, 2009

An interesting feature of the intellectual world is how little we understand about persons. This creates problems in deciding what policies to adopt in the context of life and death. The three dominant theories of a person assert that a person is an organism, a physical object, or a soul. All three are inadequate.

The notion that a person is an organism fits nicely into what we know about biology. Because we think that human beings are animals and that animals are organisms, it follows that human beings are organisms. An organism is just a living being. A fairly standard account of life is put forth by Paul Davison. On his account, a being is living or alive if it is composed of cells, metabolizes nutrients, grows, reproduces, responds to stimuli, regulates its internal environment, etc. This theory fits cleanly with the notion that human beings are merely animals whose distinctive features resulted from natural selection.

The problem with this theory is that it generates absurd results. For example, a proponent of the persons-are-organisms theory has to assert that at death an individual ceases to exist. On this theory, because a person is a living organism and because a corpse is not living, a person is distinct from his corpse. Philosopher Fred Feldman points out the ridiculous results that follow from this. For example, the individual we see sitting in an open coffin is not the one who was a great husband and father, stormed the beaches of Normandy, cheated on his taxes, etc. In addition, if a person died while wearing a tuxedo, then someone must have removed him and replaced him with the corpse, all without undoing the buttons. This theory claims that it is not just that the person changes when he dies, but rather that he ceases to exist and a new thing (the corpse) takes his place.

Worse, on this account, persons can survive brain replacement. Imagine that a surgeon replaces George W. Bush’s brain with that of Barack Obama and vice versa. Intuitively, it seems that Bush is now located in Obama’s body and vice versa. Bush would think himself located in Obama’s body and find himself waking up next to Michelle. Yet this is not true on the persons-are-organisms theory. On this theory, the same organism is located in Bush’s body and hence the brain transplant does not change where Bush is located. After all, a living organism can survive the replacement of an organ. For example, people survive kidney, heart, and liver replacements.

The notion that a person is a physical object, probably a brain, fares no better. We often think that persons begin to exist when they are conceived. In other words, we were once zygotes. A zygote is an organism that comes into being at conception and exists through implantation in the uterine wall. Because zygotes do not have brains, this theory entails that people were never zygotes. This is bizarre. We pretty clearly do think that we existed before we were born, in part as a zygote.

Both the organism and brain theory have a problem with identical twins. Identical (monozygotic) twins occur when a single fertilized egg splits to form two individuals. On the persons-are-physical-objects theory, the person has not yet come into existence between the zygote doesn’t yet have a brain. On the organism theory, other problems result. If we ask which of the two twins contains the life found in the fertilized egg, we are unable to give a satisfactory answer. The twins are distinct from each other and one and the same organism can’t be identical to two distinct ones. This is analogous to how a country that splits in two can’t be identical to both of the resulting countries. If, instead, a person is a body rather than a brain, then it is again mysterious as to which twin got the original body and which got a new one.

The soul theory is even worse off than the other two. A soul is an immaterial (non-physical) object that is conscious. There is no evidence that persons can exist when they are dead or lack a brain. First, there is not a single scientific study that has located such an otherworldly ghostlike object. Second, there are no confirmed instances of persons switching bodies or existing without a body. If persons were souls that merely resided in bodies, such things are possible and we might expect to observe them. Third, there are many well-documented correlations between the ways in which people think and what is going on in their brains. The simplest explanation of this is that thinking occurs in the brain, rather than in some ghostlike soul. For example, when people get drunk or take LSD, their thought patterns change. When particular parts of a person’s brain are damaged, they sometimes lose very specific abilities. For example, brain damage can make a person unable to recognize faces, speak, or form long-term memories. It is hard to see why this would be the case if thinking did not occur in the brain.

Soul theory becomes even less plausible when we consider what happens in the case of twins. The proponent of persons-are-souls theory must claim that the soul that the zygote had went to only one of the twins or went out of existence. It is absurd to think that one twin got the old soul and one a new one when they are identically placed with regard to the original fertilized egg. It is equally absurd to assert that both twins got new souls. After all, what happened to the old one?

The issue of the nature of persons is at the forefront of some of the most heated political issues of our time. Consider stem-cell research. Whether this research is wrong depends on whether scientists do something incorrect when they destroy zygotes. In deciding whether this is wrong, we need to know whether zygotes are persons. The same is true with regard to abortion.

A different but related issue arises with regard to the comatose. For example, consider Terri Schiavo. Terri Schiavo was a woman, or perhaps merely a body, who was in a coma probably as a result of bulimia. Her husband wanted to cut off nutrition and allow the body to die. Parts of Schiavo’s brain had disintegrated to the point where she would never regain consciousness. Whether there was a legitimate interest in keeping her body alive depended in part on whether Schiavo ceased to exist. It is difficult to answer such questions without an adequate understanding of persons, let alone a consensus on the issue. Yet this is precisely where we are.


The Objectivist said...

Note free will, at least in the liberatarian sense, requires that people are souls. Hence, the failure of soul theory carries with it painful implications. At least painful ones for those who want free will, the afterlife, moral responsibility, etc.

The Objectivist said...

I do think the brain theory is correct and that in the end we have to reject that we were zygotes.

The possible case of brain-splitting (A's brain is split and halves are put in B's and C's heads0 is a major threat the persons-are-brains theory. I'm not sure what to say about this.