The Metaphysics of Creation: Aquinas’s Natural Theology in Summa Contra Gentiles II by Norman Kretzmann (review)

BOOK REVIEWS The Metaphysics of Creation: Aquinas's Natural Theology in Summa Contra Gentiles II. By Norman Kretzmann. Oxford University Press, 1999. Pp. 483. $65.00 (cloth). ISBN 0-19-823787-1. The Metaphysics ofCreation is the sequel to The Metaphysics ofTheism and the second in a projected three-volume investigation of the "natural theology," or what Kretzmann calls "generic theism," contained in the first three books of Aquinas's Summa contra Gentiles. Kretzmann claims that his book is not a commentary but rather a "selective, critical analysis of Aquinas's natural theology" (2). Given Kretzmann's intention to show the relevance ofAquinas's natural theology to contemporary debates in analytic philosophy of religion, one would expect his selection to be governed in a significant way by contemporary currency. That is the case, for example, in a chapter entitled "Origin of Species," which is devoted to showing that certain purported oppositions between creation and evolution are wrongheaded (183-227). Yet even here Kretzmann's approach (which makes very interesting use of Aquinas's distinction between creating, distinguishing, and furnishing) has a strong textual basis. More so than the book on ScG I, this book attends to the intricate structure of ScG and especially to the prominence of dialectical skirmishes with rival, inherited philosophical positions and interpretations of Aristotle. Whereas Kretzmann had insisted on the demonstrative order of the ScG in his exposition of book I, he now speaks repeatedly of the dialectical structure and mode of inquiry of book IL His philosophical commitments and his manner of reading ScG II come to the fore in his analysis of three issues: the necessity of creation, the union of soul and body, and the incorruptibility of the human soul. In the discussion of divine creation, he follows Aquinas's line of argument fairly closely. He denies, for example, that God's perfection unduly circumscribes his creative options. He rejects the notion that God must create the best possible world if what we mean by "best possible world" is a world none better than which can be conceived (224-26). While he agrees that God is not necessitated concerning what He creates, he departs from Aquinas on the question of whether God must create. The latter necessity is not a requirement of justice, but is instead a requirement of God's goodness, following from the principle of the diffusiveness of the good. Kretzmann's position is not reducible to the necessitarian view of Avicenna, whom Aquinas is at pains to combat in 309 310 BOOK REVIEWS this section of ScG. Avicenna's necessitarianism is that of natural necessity wherein the cause is determined to one effect; it is what Kretzmann calls "single-effect causation." Kretzmann's position is that the necessity of creating is compatible with freedom concerning what to create. But what is his argument that God must create? There is an "inconsistency in the notion of goodness that is for ever unmanifested, never shared by the perfectly good, omnipotent agent." This follows from Aquinas's principle that "the sharing of being and goodness proceeds from goodness" as "its defining characteristic." Kretzmann elaborates, "a being that is good ... simply is a being productive of good things external to it" (136). Of course he is adding to Aquinas's position the term "external," since Aquinas holds that God's communication of his own goodness is completely shared only within himself. In fact, it would seem that the Trinity is God's complete self-diffusion. In a footnote, Kretzmann anticipates this line of argument and notes that Aquinas himself argues this way in the Sentences. His response is twofold. First, such arguments can have no place in natural theology; second, it is "God, not some one divine Person, whom Aquinas identifies as 'goodness itself....' Consequently ... the essential self-diffusiveness of goodness as an aspect of the essence of God remains in force, necessitating external, volitional diffusion" (135). The latter rejoinder is wide of the mark, since the basis of the Trinity is not a single Person, which would create an inappropriate inequality among the divine Persons, but rather the divine essence itself. The crucial question concerns the necessity of external manifestation, but this requirement...