Potential Persons or Persons with Potential? : A Thomistic Perspective

An article published in an earlier issue of this journal advanced the thesis that "the embryo is a potential person, because it will develop into a person if nothing prevents it" (1; p. 79). The interesting thing about this claim is not the statement itself but the author's attempt to support his claim by reference to a tradition which he traces back to Thomas Aquinas. However, the idea of potential personhood is incommensurate with Thomas Aquinas' understanding of personhood. For a Thomistic thinker the phrase ‘potential person' is a ‘contradictio in adjecto', a contradiction in terms. Showing why is what this essay is devoted to. It defends the thesis that there is no such thing as a potential person if we assume (with Thomas Aquinas) that a person is an individual substance who possesses a rational nature.
By doing so, this article is not only meant to render more precise the way we think about persons but also to refocus the content of our disputes about the problem of personhood. When we think about personhood it is not the dispute between the doctrines Baertschi (1; p. 77) has suggested to name actualism, dispositionalism and capabilitism which we should devote our attention to but a more fundamental question, namely whether personhood can and should be reduced to a mere property (or a set of mere properties) or has rather to do with ontology and substantial being.