This lecture largely focuses on the nature of personhood and its relation to natural law theory. Koterski explains that the concept of person is essential in all varieties of natural law theory. Natural law depends on there being a natural kind, in particular, a natural kind of humans. Because of rationality, humans are different, different in kind, than other animals—thus the well-known definition of man as the rational animal. We share with animals an animal nature: we have physical bodies that require nutrition, can grow and decline, can reproduce, and are able to take action. Importantly, like all animals, we have a pattern of development towards a mature individual. But humans also have rationality, which animals lack, and so require a different category.
Koterski more explicitly raises the issue of what might be called the marginal cases. Are non-paradigmatic humans (infants, senile, etc.) fundamentally different than the paradigmatic humans (what Koterski calls the normal case)? Koterski argues that natural law theory considers both to be, from a moral point of view, the same. And it is here that a new concept is needed: personhood.
Person is moral category that will demarcate who deserves protection due to its intrinsic dignity and rights. All humans, on Koterski’s view, are persons in virtue of their humanness. But, he argues, person is a wider category than human. For the religiously minded, God and angels are also considered persons. For the non-religious, one might consider forms of extraterrestrial life that meet certain standards to be persons (it seems quite plausible for there to be a rational Martian which would be a person but not a human).
Koterski argues that we should define human personhood structural—based on our biological structures—and not functionally. The functional definition would seem to leave out the marginal humans because they are incapable of performing the functions that typify humanity. This, he argues, would be arbitrary and subjective because (1) these functions can change and in some ways culturally and individually dependent and (2) because we have no clear way to demarcate the point where the human functionality comes into being. But moreover, even if we could, Koterski argues, nothing fundamental or essential has changed about the individual. The DNA and fundamental organizational principle of the being hasn’t changed, it is just being expressed more and more as the individual grows.
I should note here that I don’t think this is persuasive. Yes, the DNA is the same and the individual is a form of human life. But, there is something importantly different—the particular expression of the DNA and subsequent development has created new structures and with them new facilities and abilities that were not there prior. While I am not saying we must adapt a functional definition, Koterski and other natural law theorists are too quick, I think, to argue that there is no fundamental difference here.
Koterski develops the concept of person by tracing its historical roots back to Boethius—the 6th century Roman philosopher. Boethius defined person as “an individual substance of rational nature.” Adapting the term person from the theatrical notion of persona—the role or character played, Boethius wanted a term to convey accountability and responsibility based on the rationality of the agent.
Koterski closes out the lecture with a discussion of the social dimensions of human nature. Human nature, he notes, requires various kinds of social relationships and interactions. The forms of these interactions and relationships are dependent on a number of different factors including: history, culture, political regimes, and individual choices, but reflection on human nature indicates that some kind of social relations are essential for our proper development and flourishing.