Aquinas on Efficient Causation and Causal Powers by Gloria Frost (review)

Reviewed by: Aquinas on Efficient Causation and Causal Powers by Gloria Frost Gregory T. Doolan Aquinas on Efficient Causation and Causal Powers. By Gloria Frost. New York: Cambridge University Press, 2022. Pp. xii + 239. 99. 99 (hard). ISBN: 978-1-009-22542-7. This volume begins by noting what might seem like a modest undertaking: "to reconstruct the intriguing details of Aquinas's theories about efficient causation and causal powers" (2). It easily accomplishes that and much more. Frost's book provides the most detailed consideration of Aquinas on efficient causality since Francis X. Meehan's 1940 volume, Efficient Causality in Aristotle and St. Thomas. In the eight decades since that publication, there has been much scholarship addressing aspects of this topic, but until now there has been no subsequent full-length study. This new volume focuses on efficient causality as it occurs in the natural order: between nonrational, terrestrial substances. At first blush the focus may seem too limited but, as Frost rightly notes, there is surprisingly little scholarship dedicated to Aquinas's views on natural causality and causal powers. Instead, attention is typically directed toward his account of efficient causality as it pertains to either human or divine action. Despite the delimited focus of the volume, it draws out aspects of Aquinas's general account of efficient causality that have relevance for other areas of his thought, such as ethics, metaphysics, and even revealed theology. This broader value follows from Frost's methodology, which has three major aspects: (1) analyzing Aquinas's views regarding the fundamental relationship between natural efficient causes and their effects, (2) identifying the ontological elements involved in the paradigm cases of natural efficient causality for Aquinas, and (3) addressing his treatment of more complicated cases of natural efficient causation. The result is a volume that will be an invaluable resource not only for students of Aquinas's philosophical thought, but also for those of medieval philosophy in general, and even for contemporary philosophers seeking a better understanding of premodern accounts of causality. The volume is divided into two major parts. The first is on the general topic of elements involved in paradigm instances of efficient causation—that is to say, instances of per se efficient causality. To situate the reader, Frost begins in chapter 1 by providing an overview of Aquinas's theory, central to which is the ontological character of causality. For Aquinas, causality does not entail a mere End Page 357 logical or conceptual relationship between effect and cause but, rather, a relationship of real dependence of the former on the latter. Frost briefly traces out how this relationship is relevant for each of the Aristotelian four causes. Of these, however, only efficient causes influence the being of their effects through action. Natural agents in particular do this through inducing a form in preexisting matter. Frost carefully notes that, for Aquinas, such induction is not essentially required for efficient causality as such, as is the case with God's acts of creation and conservation. Still, since this volume is concerned with natural agency, the focus in the pages that follow is principally a consideration of such agency, together with an examination of the active powers that pertain to the actions of natural agents. Frost proceeds to trace out and explain the key elements of per se efficient causality, which the subsequent chapters of this book examine in detail. Before turning to that examination, however, she provides in chapter 1 further background by drawing a contrast between Aquinas's theory of causation and other models, notably Humeanism and Nomicism. This consideration is followed by some historical background on sources that influenced Aquinas, along with a comparison of his views with those of some of his contemporaries. The concluding section of the chapter provides something of a glossary of key concepts and terms pertaining to Aquinas's theory of causality, indicating to the reader both Aquinas's Latin and the English translations that Frost has chosen to employ. In a manner analogous to the lexicon that is Book V of Aristotle's Metaphysics, this section offers a helpful point of reference to the reader and will be useful for teachers of Aquinas. . .