Virtually every philosophical school in antiquity is defined by its peculiar account of primary explanatory principles. With the exception of Atomism and Skepticism (which is defined by its opposition to the very idea of philosophical explanation), most of the ancient schools associated divinity with such principles. They also shared the tendency to reductionism—the fewer and simpler the principles the better—along with a tendency to limit the attribution of divinity to the fewest possible number of gods, ideally, hierarchically arranged. The trajectory of this line of thinking was to identify the supreme divinity with the ultimate explanatory principle. Among Platonists, who dominated philosophical discourse for most of the later history of ancient Greek philosophy, various versions of a first principle of all were hypothesized as well as various theories about how the logical exigencies of an explanatory principle could be combined with the supposedly personal properties of divinity. (Reconciling absolute explanatory scope for this first principle with the existence of evil in the world is perhaps the most well known of the myriad challenges that these philosophers faced.) In every case, speculation began with two sorts of evidence; on the one hand, Plato’s writings on the superordinate Idea of the Good, the other Forms, and the Demiurge, and on the other, Aristotle’s testimony about Plato’s account of first principles both in the dialogues and in his “oral teachings.” In later discussion, however, Aristotle’s own contribution to the debate on a first, divine principle itself became a fundamental element. Specifically, the central issue was whether Aristotle’s Prime Unmoved Mover (PUM) was a critical and mutually exclusive alternative to the Platonic triad Good/Demiurge/Forms, whether it was a fragment consistent with the larger Platonic picture, or whether it was just the triad expressed in other terms.
In her thoughtful and challenging monograph, Gwenaëlle Aubry examines Aristotle’s account of the PUM, especially as it appears in Book 12 of his Metaphysics, and then turns to an account of Plotinus’ effort to reconstruct what he took to be the authentic Platonic position in the light of Aristotle’s arguments. About two-thirds of the book is devoted to Aristotle and one-third to Plotinus. Aubry’s focus in the first part of the book is on Aristotle’s theology in relation to the science called a science of “wisdom,” of “first principles or causes,” and of “being qua being.” The problem of how theology is related to a science of being qua being which, according to Aristotle, amounts to a science of substance, is one of the central issues in Aristotelian scholarship. Indeed, the difficulty of seeing how the two are connected in the collected treatises known as Metaphysics is probably one of the reasons for that work’s sporadic and sometime even nonexistent influence within the tradition: it is difficult to be an advocate for or against a position so elusive.
Aubry, who is impressively steeped in the secondary literature, follows for the most part the interpretation of Pierre Aubenque in his influential Le problème de l’être chez Aristote (Paris, 1962). According to this interpretation, Aristotle does not in fact intend to identify theology with a science of ontology or being qua being. Rather, theology is to be understood as only one part of that science (pp. 20-8). General ontology is taken to be a study of substance, which is in turn analyzable in terms of act ( energeia) and potency ( dunamis). The unqualified act of the PUM is only one type of act, albeit the most important. Because its act is, uniquely, unconnected to any potency, the relation between the act of any composite and its potency is only analogous to the relation between the act of the PUM and everything else (p. 148). The principle consequence of the separation of ontology and theology, on this view, is that when Aristotle argues for the identification of the PUM and the principle of the good, he thereby decisively separates theology and ethics from ontology (pp. 195-200). The latter science determines the general relation between being and the good (in terms of act and potency), and the former sciences apply these results.
Aubry argues both against the cogency of the traditional interpretation that identifies theology with the science of being qua being and for a heterodox interpretation of some crucial passages in the text that apparently serve as signposts along the path Aristotle is taking. On the traditional interpretation Aubry rejects, Aristotle’s analysis of sensible substance in the central books of Metaphysics leads him to conclude that the form of the sensible substance is the source of the being in it. Hence, the quest for the primary referent of “being” points to an absolutely separate or “pure” form. Also on the basis of the analysis of the central books, such a form would be identical with an act, which is exactly how the PUM is characterized. So, her opponents think, the science sought finds primary being in the unqualifiedly perfect act that is the PUM. The science of that Mover is therefore the science of being qua being.
Aubry argues that there are two problems with this traditional interpretation, one fairly obvious and one not so obvious. The first is that if the PUM is, as Aristotle argues, a life comprised of thinking thinking of thinking, and a final cause, it is difficult to see how it is to be the focus of a science of the causes of being, which the science of being qua being is supposed to be. For the final causality that the PUM exercises on things that can or do consciously imitate the activity that is its life is not obviously transferable to the being of things that do not imitate that activity. If, on the other hand, one just identifies the PUM with final causality in everything that is, the ontological primacy or separateness of the PUM seems to be compromised. The second problem is that Aristotle never explicitly identifies primary being with “pure” form (p. 184). On the contrary, his polemic against Plato’s Forms seems to lead him to conclude to the impossibility of pure, that is, separate, form. So, it would be a mistake to take form (which is never “pure”) as synonymous with act (pp. 63-87). But this is exactly what the traditional interpretation must do.
Regarding the second problem, Aubry argues that the being of sensible composites is one type of act or actuality—that of the sensible form combined with matter or potency—and the being of the PUM is another. In short, there is no “focal reference” or pros hen equivocity between form and unqualified actuality sufficient for the construction of a science of being qua being as hypothesized in Book 4 of Metaphysics. There is only an analogy between these and that is not sufficient to establish a universal science. Consequently, the science of ousia or of being, like all other sciences, must seek in some other way to understand that which is common to (that is, univocally predicable of) all substances, whether these are unqualifiedly separate or not (p. 193). Theology will be the science of being as act, and will exclude from its scope the being of everything else not identical with its act (that is, everything that is a composite of act and potency) (p. 194). On the basis of this argument, Aubry can then respond to the first problem, maintaining that since theology is not supposed by Aristotle to be the focus of the science of being, the attributes of the PUM need not be taken as the attributes of being as such. And the pros hen equivocity supposedly the key to the special science of being qua being can be understood as the relation of the final causal activity of all substances to the PUM as their final cause (p. 199).
But, while it is true that Aristotle does not explicitly identify act with “pure form,” he does seem to treat them as close to synonymous in several passages (8.2.1043a28; 8.3.1043b1-2; 9.8.1050b2-3). More important, to claim as Aristotle does that the forms of sensibles do not exist apart, does not mean that these forms are not the principles of actuality in sensibles. It certainly does not preclude that an act that does exist apart is the pros hen focus of the sort of act that forms are. Aubry seems to admit as much on when she allows that act is identified with ousia and that the ousia of sensibles is found in their form (p. 109). In addition, if the science of being qua being has to be a science of that which is univocally predicable of all beings, Aristotle’s own arguments against such a science have to be ignored.
Aubry’s case depends heavily on the interpretation of two well known and deeply contentious passages in Metaphysics. The first is at 6.1.1026a24-32, in which Aristotle raises the question of the hypothetical universality of first philosophy, and the second at 12.1.1069b1, in which Aristotle says that the study of immovable substances (i.e., theology) belongs to a science different from physics “if no principle is common to these and to sensible substances (i.e., both destructible and indestructible sensible substances).” As Aubry points out, if this condition were not met, theology would be physics; but that cannot be, since physics deals only with the movable qua movable. Theology is indisputably a science different from physics. But then we must accept that there is no principle common to theology and physics. This means in turn that theology is not to be understood as identical with the science of being qua being or first philosophy.
This interpretation of the passage in Book 12 leads Aubry to deny that the universality of theology referred to in Book 6 is the universality of a science that would include within its scope physics; the universality of theology is not the universality of the science of being qua being. Its universality is like the universality of universal mathematics, the generic (and so, univocal) science of quantity (1026a25-7). When Aristotle explicitly identifies theology as concerned with being qua being, he should be taken to mean that it is concerned universally with being qua being only ” au sein d’un genre d’êtres déterminé” (p. 194, author’s emphasis), like mathematics. It is concerned with being only in the case in which being is identified with act.
First, however, let us note that the passage in Book 6 gives as the reason for the universality of the science of immovable substance is that “it is first.” On Aubry’s interpretation, this reason is otiose. Further, the universality of the science (as first philosophy) is the alternative to its being “concerned with one genus.” The latter alternative is clearly rejected in the claim that first philosophy is universal. To the extent that Aubry wants to interpret Aristotle to mean that theology focuses on a distinct kind of being, she seems unable to account for this rejection of the latter alternative. To the extent that she allows that theology is not limited to one kind of being, she seems forced to admit that the universality of that science refers to its comprehensive scope, that is, its inclusion somehow of all being.
Perhaps more importantly, Aubry interprets the passage in Book 6 the way she does because of her interpretation of the passage in Book 12. If indeed theology and physics have no principle in common—if the condition mentioned in the passage is not met—then we would be forced to understand the universality of theology other than as it has traditionally been understood. But Aubry offers no reason for thinking the condition is met other than that not meeting it would mean that theology and physics would then be identified. However, it does not follow that if theology and physics have a principle in common that these two sciences would be identified. Physics studies being qua movable; first philosophy studies being qua being, including the being of movable things. So, physics and first philosophy can have a principle in common (the principle of being), though they are distinct sciences. Indeed, it is possible that theology, understood as the science of all immovable substances can have a principle in common with physics, that principle being just the PUM. This possibility makes theology distinct from physics and from the study of the PUM or being qua being, but only if the study of being is the study of a pros hen equivocal. That is, just as we can study physical objects qua movable or qua beings, so we can study immovable objects qua immovable or qua being.
The second and shorter part of this book seeks to show how Plotinus’ conception of the first principle of all differs from Aristotle’s and is in effect an interpretation of the Platonic principle that Aristotle rejects. Aubry here wants to show that Plotinus’ argument for the One as “power of all” ( dunamis twn pantwn) constitutes a major shift away from the idea of act as final cause to that of act as productive (213). This shift is a sort of midway point between Aristotle’s position and the later Christian position of God as omnipotent creator. In an Aristotelian context, it is at first strange to see the unique, perfect, and absolutely first principle of all being described as dunamis, though it is obvious that Plotinus is following Platonic language (cf. Rep. 509B9-10). Still, once a distinction between act and potency is made by Aristotle (a distinction to which Plotinus largely adheres), it seems puzzling that Plotinus retains this terminology. For potency in Aristotle always indicates a certain incompleteness in whatever has it. This includes active potency, that is, the potency for producing something in something else. Anything with an active potency is, by definition, not yet that which it could be if or when it actualizes that potency. Even if what it is not yet does not suggest an imperfection in a thing’s specific nature, still, the capacity for being something other than what something is here and now is a sort of incompletion that it has. This was presumably Plato’s point in Symposium in saying that erws always indicated a lack. And, as Aubry recognizes, if anything is clear in Plotinus’ Enneads, the One lacks nothing.
It does not, I think, solve the problem to claim that the One has “puissance infinite” (p. 219), if “puissance” here is understood as an active potency. It is by thinking of the One as having an active potency, whether finite or infinite, that an interpreter is led to identify Plotinian emanation with creatio ex nihilo. If the One is transcendent, it is unqualifiedly so, and I take this to imply creatio ex nihilo. But it is fairly clear, I believe, that this is not the way to understand Plotinus. His One does not create things ex nihilo. It is more correct to say that all things are in it rather than that it transcends all things. Aubry interprets dunamis pantwn as a kind of active potency in part because she wants to contrast Plotinus’ One with Aristotle’s PUM, which is identified with act. It is true, as Aubry points out, that Plotinus claims that the One is epekeina (“beyond”) the act of Intellect that is identical with ousia (22.214.171.124-10; cf. p. 261). And yet he also argues at 126.96.36.199-15, that the One is nevertheless act, indeed, perfect act. According to Plotinus, Aristotle was correct to identify the first principle as act; he was wrong to understand that act as thinking, since thinking involves a complexity that cannot belong to the absolutely simple first principle of all.
The crucial question is thus whether Plotinus’ conception of the act of the first principle is fundamentally different from Aristotle’s. This is a question primarily about causality. Aubry’s argument for the exclusive final causality of the PUM, leads her to stress the difference between this and the productive causality of the One (pp. 222-39. 285). She makes a useful distinction between the productivity of the One considered as “efficace” and as “efficient,” arguing that attributing to it the latter would imply a movement or action that it does not have (p. 233). It is nice question for further investigation exactly how different this efficaciousness is from the causality of the PUM “upon which the heavens and nature depend.” At the end of the book, Aubry herself seems to have some doubts about the depth of the differences between Plotinus and Aristotle regarding the first principle of all (p. 283, but see p. 285). She ends this impressive study insisting on Plotinus’ abandonment of the Aristotelian approach, which is to think and love “le bien et non pas la puissance (p. 286).” If one believes that this approach is really different from Plato’s, then one will naturally be inclined to interpret the position of Plotinus, Plato’s disciple, as the abandonment of it. Aubry has not convinced me that Plotinus’ Platonism constitutes “une rupture radicale avec Aristote.” Others, however, will not need much convincing of this. But anyone interested in working through the reflections of Aristotle and Plotinus on Plato’s central metaphysical tenet will benefit handsomely from this exceptional book.