This welcome volume is part of a small but growing body of literature that aims to treat the Church Fathers as philosophically articulate and sophisticated thinkers, ones that – for theological purposes – are content to borrow freely from late antique philosophy. After providing an extensive background on the question of divine simplicity from Clement to Eunomius, Radde-Gallwitz argues that Basil and Gregory of Nyssa borrow from Porphyry and elsewhere the notion of a proprium (a necessary but non-defining property), and maintain that many (not all) of the terms we truly predicate of God signify such propria. This, according to Radde-Gallwitz, allows the Cappadocian brothers to avoid two extreme accounts of our knowledge of God. The first view identifies God's attributes with each other and with God, and Radde-Gallwitz interprets this as entailing that God's essence is somehow known by us. The second, contrariwise, maintains that God's essence is distinct from the ways in which he is related to us, and that while the latter are known, the former is not: and on this view, no intrinsic divine property is known by us. It is the first view on this analysis that is relevant to the Cappadocian rejection of Eunomius's theology, according to which God's essence is ingeneracy, and all other divine attributes are identical with this essence.
The Cappadocian solution is this. Basil and Gregory hold that we can in some sense know God under different conceptualizations (epinoiai). These epinoiai correspond to divine propria, and these propria are not merely mind-dependent entities. Claiming that the propria are not merely mind-dependent means that the Cappadocians would reject ‘an entirely non-realist or nominalist interpretation’ of the epinoiai, ‘according to which all theological claims are only conceptualizations’ (p. 177). But the Cappadocian commitment to divine simplicity means that they would reject too a ‘hyper-realist’ interpretation of the epinoiai: ‘Nothing [Gregory] says leads us to believe that the concepts discovered by means of epinoiai have external “referents”’, or that Gregory and Basil ‘view epinoiai as constituent, inherent aspects of objects’ (p. 177). Now, as far as I can make out, what distinguishes Radde-Gallwitz's via media from the hyper-realist view (since the via media clearly adopts some kind of realism about properties) is that the hyper-realist view makes the relevant properties ‘constituents’ of the divine essence in a way that the position ascribed by Radde-Gallwitz to the Cappadocian brothers does not. Thus, for example, Radde-Gallwitz has no problem with the thought that, for Basil and Gregory, propria might inhere in the divine nature (p. 202); but they are not constituents of this nature. Hence the divine essence itself remains unknown. (Radde-Gallwitz finds the inherence view in Gregory; he clearly thinks that Basil is more vulnerable to Eunomius's constitution objection, according to which distinction in epinoiai entails distinction intrinsic to the divine essence.)
What should we make of this reconstruction? It seems to me that the ‘nominalist’ understanding of Gregory's theory of epinoiai is exactly right, and the reason why I believe this to be the case rests in part on the grounds that Gregory's persistent response to Eunomius on the issue is to insist that non-synonymous predications can be true of God even in the absence of any kind of distinction in the divine substance, nature, or essence. What warrants these true predications is simply the one simple object itself – God, or the divine substance, nature, or essence. There is nothing intrinsically controversial about the claim that predications can be true even in the case that the predicates do not correspond to some real feature of the world somehow distinct from the subject of predication: it is a standard feature of many modern semantic theories, for example, that we do not need there to be a real feature in reality corresponding to every predicate. (Consider conjunctive or disjunctive predicates, for example, or relational predicates generally.) It is Eunomius, not Gregory, who confuses the semantic with the metaphysical (as Radde-Gallwitz correctly notes at one point: ‘Eunomius has confused grammatical distinctions with ontological ones’ (p. 181)). The truths of the relevant predications are not dependent on any real ontological distinction in God.
So what is Radde-Gallwitz's evidence? On a careful reading, it seems surprisingly spare, and as far as I can see it is based simply on an interpretation of a highly sketchy definition of epinoia offered by Gregory as a summary of Basil's understanding of the term (an understanding with which Gregory, of course, agrees):
‘Having formed an idea about a matter in hand, we attach the next thing to our initial apprehension by adding new ideas, until we bring our research into the subject to its proposed conclusion.’ (p. 177, quoting Gregory, Eun. 2.182)
Radde-Gallwitz comments:
One must begin with an apprehension before one can engage in conceptualization. If [this] is the method for making additional discoveries based on an initial concept, then one of two claims must be true. Either every initial concept is the product of conceptualization, in which case there would never be an original concept to start the process of discovery, or some concepts are not devised through conceptualization. (pp. 177–78)
The latter disjunct, of course, is the one Radde-Gallwitz defends. Now, as Radde-Gallwitz well knows, the quoted passage is part of a description that Gregory offers of Basil's approach not to a theory of properties but to an understanding of how one might go about the investigation of an academic or scientific discipline. It is not supposed to be part of the theory of propria that Gregory develops, but merely a description of a scientific methodology illustrative of the notion of an epinoia. We start from one idea – whatever the source of that idea – and then continue the investigation. But we cannot investigate without an initial idea. I do not see what bearing this has on the rejection of a nominalist theory of propria. After all, one might think that all propria are epinoiai (at least in the divine case), and Gregory himself is explicit that there is nothing else that we can know about God (e.g. his essence) – so in divine science there can hardly be a starting point that is somehow simply apprehended. It is the utterly mysterious and unknown divine essence that warrants our predicating the divine propria of God, and its doing this does not require that the predicates somehow name properties that have some distinction in God more than a merely mental one. It is not for nothing that the central texts Radde-Gallwitz analyses (at pp. 200–07) persistently refer to divine propria as names (a fact that he does not note), and that his careful retranslations of some of these texts (pp. 204–07) make it clear that Gregory's interest lies simply in securing the relevant ontological conditions for the truths of predications such as ‘God is good’. And, in the texts discussed, the point is that this condition is simply the (unknown) divine essence. So, all in all, a fine and thoughtful contribution to an important debate, but I doubt that the conclusion is correct, and I am certain that Radde-Gallwitz has not provided sufficient evidence for it.
