Abstract

The chapter provides a response to Patrick Toner, “Critical Study of Fabrizio Amerini’s Aquinas on the Beginning and End of Human Life,” Oxford Studies in Medieval Philosophy 2, 211–28. The chapter corrects two misrepresentations in Toner’s review. First, it proves that, given Aquinas’ assumptions on substantial form and human soul, Aquinas could not give up his preference for delayed hominization of the embryo even if he were acquainted with contemporary embryology. Aquinas takes as the starting point of his embryology Aristotle’s characterization of the human soul as the act of an organic physical body having life potentially, and this characterization leads him to the conviction that the human soul can enter into the human body only after the principal vital organs are formed. Second, the chapter corrects Toner’s unusual interpretation of the clause “organic” in the Aristotelian characterization of the human soul, by specifying the different senses of potentiality in Aquinas’ embryology. The chapter reaffirms the core idea that establishing when the hominization of the human embryo begins is not decisive for rejecting abortion. The chapter suggests relating the question of abortion to the identity or continuity of the human embryo rather than to the beginning of hominization.