BOOK REVIEWS 145 arguments concerning them, and thereby gives an indication of a “style” of thinking that underlies those arguments. FREDERICK CHRISTIAN BAUERSCHMIDT Loyola University Maryland Baltimore, Maryland Basil of Caesarea, Gregory of Nyssa, and the Transformation of Divine Simplicity. By ANDREW RADDE-GALLWITZ. Oxford: Oxford University Press, 2009. Pp. 272. $100.00 (cloth) ISBN: 978-0-19-957411-7. Divine simplicity has long been a contested issue. Although there are powerful reasons for concluding that God is in some way preeminently simple, there are also serious difficulties in doing so, among them that of understanding how a perfectly simple God could possess what at least seem to be a multitude of properties. The book under review examines some of the earliest attempts to deal with this issue. Although its primary focus is on Basil the Great and Gregory of Nyssa, there are also substantive discussions of Ptolemaeus Gnosticus (a second-century critic of Marcion), Clement of Alexandria, Origen, Athanasius, and Eunomius. It exhibits a high level of scholarship and is often helpful on points of detail. Nonetheless, the book’s fundamental line of interpretation seems to me to be mistaken. I will first summarize the main outlines of this interpretation and then offer a criticism of a central point. The author observes, rightly enough, that the philosophical context for the earliest Christian discussions of divine simplicity was supplied by Middle Platonism. The Middle Platonists distinguished sharply between the highest, unknowable God and a lower, demiurgic God who in some obscure way derives from the first. The highest God is wholly simple, unknowable, and not directly engaged in the world; the second God is simple only in relation to creatures, but can be known via nous (the faculty of pure intellectual apprehension) and is, in at least some versions, identical to Plato’s realm of the Forms. Christians found this fundamental scheme appealing as a way to understand the relationship between God the Father and the Logos, and versions of it are to be found in Ptolemaeus, Clement, and Origen. A second sort of answer to the problem of divine simplicity began to emerge in the theology of Athanasius. Athanasius was an early advocate of what RaddeGallwitz calls the identity thesis, the claim that divine simplicity is best understood as implying the identity of the divine essence and attributes. Admittedly Athanasius does not state this thesis categorically, but he does assert BOOK REVIEWS 146 that God has no accidents or “essential complements” and hence that terms such as ‘God’ and ‘Father’ must name the divine essence itself. This notion was picked up by Eunomius, who saw (as Athanasius had not) that it could be used to support Arianism. For Eunomius, ingeneracy is, as it were, the master divine attribute to which all others are equivalent; and since the Son is not ingenerate, he cannot be God. The essential contribution of Basil and Gregory, according to Radde-Gallwitz, consisted in finding a way to understand divine simplicity that requires neither the identity thesis nor the radical apophaticism of the Middle Platonists. Both of these views have at their root what Radde-Gallwitz calls the thesis of the epistemological priority of definition, the idea (found most obviously in Aristotle’s Posterior Analytics) that knowing an entity requires knowing its definition. Basil and Gregory, by contrast, recognize that there can be knowledge of the divine substance or essence (ousia) that is not in any way tantamount to a definition. What can be known are the divine “propria,” distinguishing characteristics such as light, wisdom, power, life, truth, goodness, and incorruptibility that are coextensive with and intrinsic to the divine essence but do not, either individually or collectively, constitute its definition. This use of the term ‘proprium’ (Greek idiÇma or idiot‘s) may be a bit confusing because in Aristotelian logic a proprium is a property that follows directly from the definition of a substance, as, for example, having interior angles that add up to 180 degrees follows from the definition of a triangle. Basil and Gregory do not claim to know the definition of the divine substance, and so make no claim regarding whether the propria follow from it. Their position is simply...