The Metaphysics of Creation: Aquinas's Natural Theology in Summa contra gentiles II (review)

Thomas Aquinas is astounding not just for the richness, complexity and timeless interest of his thought, but for the sheer bulk of his works. The challenge this bulk presents to commentators has been taken up in various ways. Some people focus on Aquinas's architectonic, giving a global overview of individual works in such terms as the neo-Platonic exitus-reditus schema; others focus on the interplay of faith and reason in his works by classifying Aquinas as a theologian, or a Christian philosopher, or a philosopher-theologian; still others try to organize his thought by bringing together thematically-linked discussions from a variety of places. All three approaches tend to overlook perhaps the most striking feature of Aquinas's writings: the continuous progression of carefully-formulated, detailed arguments and sub-arguments.

In the second book of his uncompleted trilogy on Summa contra gentiles, Norman Kretzmann combines the best of the first two approaches to Aquinas with an impressive and largely successful attempt to come to terms with Aquinas as an arguer. He takes an ample selection of Aquinas's own arguments in their order of appearance in SCG II; he analyzes their premisses; he shows how they function in relation to earlier and later arguments; and he criticizes their weaknesses. He does all this in an elegant, lucid prose that ensures the attentive reader an enhanced understanding of the specific topics discussed by Aquinas.

To understand the full import of the arguments examined, however, we need to consider what Aquinas hopes to achieve by his sequences of arguments. While granting that Aquinas is a theologian, and that he intends his Summa contra gentiles to give a full account of what Christians believe, Kretzmann argues that the first three books of SCG present a fully-developed natural theology which can serve as guide and inspiration to thinkers today. The key to understanding Aquinas here is the recognition that the philosopher, particularly the metaphysician, is, or should be, concerned with the first principles and most ultimate aspects of reality. If it turns out, as most philosophers before the twentieth century have believed, that these first principles are divine, then truths taught by revelation can be integrated with truths arrived at by reason. Moreover, once the existence and nature of God have been established, or at least rendered plausible, one can take God as a starting point for the explanation of this-worldly phenomena, from the nature of the physical world to the nature of the human person. This explanation, while buttressed by references to Biblical revelation, will nonetheless be fully natural, insofar as it relies on arguments whose premisses are those available to any rational being independently of revelation.

In his earlier book, The Metaphysics of Theism (Oxford, 1997) Kretzmann examined the start of Aquinas's natural theology, the movement from things around us to God. In The Metaphysics of Creation, finished just before his death, Kretzmann takes up the emergence of things from God. The book is divided into three unequal parts. First, there is a long discussion of Aquinas's view of creation, and the precise way in which the world is dependent upon God, its first cause. Particularly notable in this section is the discussion of Aquinas's view that creation is compatible with the notion of a beginningless world. The second, very brief, section takes up Aquinas's treatment of the emergence of different species, and his willingness to reject the kind of literal reading of Genesis espoused by contemporary creationists. The third and longest section takes up the nature of the human mind or soul. What makes this section particularly interesting is its emphasis on the implications of the top-down approach. If we start with the ideas that God is a pure intellect, and that immaterial substance is possible, then the mind-body problem becomes that of explaining how intellect can ever be closely related to matter, rather that...