There are certain genetic compositions that make a human being part of one species and not another. However, just as in the personhood problem, one characteristic of genetics is not sufficient to thoroughly define a human. Take for example the following statement, “a human is someone with forty-six chromosomes.” At first thought, this does not seem to be a problem. However, one has to consider those classified as human beings that do not possess a full set of 46 chromosomes or those who possess mutated sets. These humans would be those suffering from Down syndrome, trisomy 18, and Patau syndrome to name a few. Certainly those suffering from such disease are still considered to be of the same species as the rest of us. Also, certain physical characteristics cannot be the lone judge of what makes a human. Members of our species differ in skin color, hair color, eye color, height, weight, number of fingers, number of toes, etc. There are many attributes that all combine to form a member of the species we know as humans. As none of the previously mentioned genetic and physical characteristics solely determine membership of the human family, they also do not solely determine membership of personhood. Also, as shown with the regression problem, free will and reason do not solely determine membership. It is the combination of all of these aspects that make a human a person.
Harry Frankfurt delivers a well thought out argument if one agrees with all of his premises, particularly the first. However, most of his premises leave much room for doubt. His argument can easily fall into the trap of hard determinism if one considers the problem of infinite regression of our volitions and desires. Therefore, if we take his sole characteristics of free will and reason to be the only components of personhood, we too can fall into the trap of believing in its non-existence. What makes a person may not only be species-specific, but it is also not entirely volition-specific. Personhood is any combination of the two, uniquely and intricately woven into the make-up of every human.
It may seem silly to any non-philosophers as to why we debate this particular issue. Many cannot see exactly why it matters and how it impacts society in any way. To those people who consider the study of such philosophical issues unimportant, I point to historical examples when clear logical thinking could have saved millions of real, human lives. There is the example of slavery in America when our own government decided that a whole race of people were only 3/5ths a person because of a certain physical characteristic, their skin color. There is the example of the Holocaust in Nazi Germany when, once again, an entire race of people were classified as non-persons (and therefore disposable) because of their genetic make-up. It is essential to the world today to understand the true definition of personhood because of such dangerous applications possible in the real world. Therefore, I will conclude that personhood should be applied to all humans regardless of race, sex, age, stage of development, level of dependency, or socio-economic status. “A person is a person, no matter how small” (Horton Hears a Who!).
BonJour, Laurence, and Ann Baker. "Personal Identity and Free Will." Philosophical Problems. Pearson Education Inc., 2008. 275-83.
Horton Hears a Who! Dir. Jimmy Hayward, Steve Martino. Blue Sky Studios, 2008.
"Person." Def. 1. Merriam-Webster Online Dictionary. 2009.