Abstract

In lieu of an abstract, here is a brief excerpt of the content:Reviewed by:Aquinas on the Beginning and End of Human Life by Fabrizio AmeriniPatrick LeeAquinas on the Beginning and End of Human Life. By Fabrizio Amerini. Translated by Mark Henninger. Cambridge, Mass.: Harvard University Press, 2013. Pp. xxii + 260. $29.95 (cloth). ISBN: 978-0-674-07247-3.This book provides a comprehensive and textually grounded presentation of Thomas Aquinas’s teaching on embryology and an assessment of its bioethical implications. Despite (what I regard as) some mistakes on the application of that teaching to contemporary embryological data, it is an invaluable sourcebook for Aquinas on this issue. At times, Amerini’s “aporetic” style makes for convoluted arguments, but it raises challenging questions and thus will assist anyone working through these issues. (As the title indicates, it also treats the end of life—but only very briefly, in a couple of pages near the end of the book.)The first two chapters examine Aquinas’s general principles regarding matter, form, and substantial generation (the coming to be of a substance), and his positon on the human soul as both subsistent and the substantial form of the human body. Amerini’s treatment is thorough and provides an extensive bibliographical guide to this issue. However, it seems to me that Amerini is less than clear on the distinctiveness of substantial change. Since there are (according to Aquinas and Aristotle) no degrees in the category of substance, generation is not a process but an instantaneous change. Amerini’s frequent use of the term “process of generation,” as well as the position he later proposes on the identity of the embryo, seems to conflict with that point. [End Page 489]Chapters 3 and 4 contain detailed exposition of Aquinas’s basic embryological position, and chapter 4 raises various questions about this position (including doubts that Amerini evidently has about the unicity of the human being’s substantial form). Applying his basic metaphysical principles to what he at the time believed were the embryological facts, Aquinas concluded that the human being with a rational soul is not present until forty days after fertilization for males or ninety days for females. The father and the mother generate the offspring, but the mother provides only the material cause in the form of menstrual blood; the father is the efficient and formal cause, acting through the semen as an instrumental cause. With the power (virtus) of the principal cause in it, the semen gradually organizes the menstrual blood provided by the mother to form, first, a being with a vegetative soul, then an animal, and finally an animal with a body suited to be formed by a rational soul, which God then infuses into it. Aquinas holds that, unlike a sensitive or vegetative soul, a rational soul must be directly created by God, since the rational soul is the source of operations that are independent of matter, that is, performed by the human being but without a bodily organ. Only matter that is suited to a form can receive it. Therefore the matter must be suitably disposed. Just as one can make a knife only with matter capable of supporting its function—and so the matter must be hard and capable of being sharp—so only a body with sense organs, and thus capable of supporting those actions prerequisite to rational operations, can receive a rational soul.Chapter 5 sets out in detail Amerini’s exposition and interpretation of Aquinas on the identity of the embryo. Amerini recognizes, of course, Aquinas’s mistakes and ignorance regarding basic embryological facts—inevitable given the time in which he wrote. Still, Amerini holds that Aquinas’s main conclusion regarding delayed hominization is still valid. He agrees with Aquinas that the general proportionality requirement implies that the embryo/fetus must first possess sensory organs to have a body apt for the reception of a rational soul.On the other hand, Amerini also advances what he believes is a via media between proponents of delayed hominization and proponents of immediate hominization. He argues that although the embryo is not numerically identical with the human being (which comes to be only with the infusion of the rational soul), nevertheless, the embryo from...