Maddalena Bonelli's book on Alexander of Aphrodisias' commentary on Aristotle's Metaphysics is a valuable addition to the developing scholarship of ancient Aristotelian commentators, of interest both to Aristotelian researchers, historians of philosophy, and metaphysicians at large. The book is a monograph, structured in six chapters, that offers a detailed and insightful presentation of the work of Alexander as a commentator of Aristotle, and most interestingly, as an original thinker of his own.
The focus of the book is on Alexander's conception of metaphysics, of its status as a science characterised by its peculiar subject matter, axioms and demonstrations. This is a worthwhile research topic, and Bonelli's contribution opens an explorative venue for both metaphysicians and ancient scholars to pursue.
What will capture the interest of the scholars is the fact that Bonelli makes the key issue of her investigation the genealogy of Alexander's own philosophical position. She makes a very interesting study of the method of commenting on the Aristotelian text that Alexander has applied and which somehow heuristically led him to an original conception of metaphysics as a demonstrative science. Bonelli finds the origins of Alexander's own view in a misunderstanding on his part of the Aristotelian text. Alexander, as Bonelli explains (e.g. pp. 29-30), is far from wanting to differentiate his own position from his master's, or of correcting or integrating it. Actually he is not even aware of putting forward an original position. Alexander is on the contrary a typical commentator of his time, who believes in the overall consistency and exhaustiveness of the Aristotelian corpus. His guiding principle in commenting on the Aristotelian text can be expressed by the slogan 'understanding Aristotle through Aristotle', namely explaining a particular passage in the light of another, even if from a different work of Aristotle, on the assumption that the Aristotelian doctrine is a complete and consistent system. It is from the application of this interpretative method that Alexander's original thoughts stem. The way Bonelli picks up this issue is informed by an extensive analysis of Alexander's texts and is well-argued on that basis.
On the other hand, most of the monograph is devoted to the reconstruction of Alexander's position about metaphysics being a demonstrative science. It is regrettable that the reader is not helped to appreciate the originality of Alexander, because no overall comparative view of Alexander and Aristotle's positions is offered. Nor does Bonelli engage much with the views of other scholars (e.g. Berti, McKirahan, Barnes, Bolton), who discuss the Aristotelian structure of sciences, which would be of relevance to the topic she is interested in. It would also have been better if Bonelli had placed Alexander's position within the broader context of the debate on the nature of metaphysics. She does not enter such debate and shows her awareness of it only in a footnote (p. 55 n. 70), where she contrasts Alexander's view on metaphysics with the one she calls 'standard' without elaborating on it.
In the first chapter of the book Bonelli introduces Alexander, his activity as commentator and the relevance of his commentary on Aristotle's Metaphysics, and describes the historical context. Bonelli shows great erudition in the multiplicity of references to primary as well as secondary sources on Alexander and his work and offers an agile and clear exposition.
The first argumentative point in the first chapter concerns the centrality of Book Gamma in Alexander's commentary. Bonelli takes this book to be at the very core of Alexander's interests. She argues that for Alexander, the first three books of the Metaphysics, Alpha meizon, Alpha elatton and Beta, are preliminary to the fourth, Gamma. Alpha meizon and Alpha elatton according to Alexander introduce prolegomena common to every theoretical discipline, and Beta shows the utility of the aporetic method in establishing the object of philosophical investigation. The fifth book, Delta, is for Alexander subordinated to Gamma as well, because in it Aristotle discusses terms and concepts applying universally to all beings and shared by all the sciences. This is why the commentary on Gamma assumes special importance for Alexander (at least in so far as the first five books of the Metaphysics are concerned, which are the only books treated in the portions of the commentary that are undoubtedly by Alexander). It is only in Gamma, Alexander thinks, that Aristotle sets out his position about the nature and the object of philosophy, and in presenting and explicating Aristotle's position in Gamma, according to Bonelli, Alexander actually displays his own originality as a thinker.
Bonelli considers Alexander's most original philosophical contribution to be his conception of philosophy as a science. His strategy is to import the theory of demonstrative-axiomatic science from the Posterior Analytics, and to show that philosophy for Aristotle conforms to that model. This is indeed the second key issue that Bonelli discusses in the first chapter of her book.
Four of the difficulties that Aristotle discusses in Beta concern the subject matter and aim of philosophy. In dealing with three of these difficulties (the one about axioms, the one about substances, and the one about the attributes of substances) Aristotle applies the model of demonstrative science as it is developed in the Posterior Analytics. But the point that Bonelli makes (e.g. pp. 44, 50-51) is that Aristotle is using such a model here precisely to show that if philosophy were to be conceived as a demonstrative science, absurdities would occur. On Alexander's understanding however, exactly on the basis of Book Beta as Bonelli explains and argues with an extensive textual analysis, philosophy is for Aristotle a demonstrative-axiomatic science. It has thereby a single subject matter, axioms, and theorems derived from them. Alexander reads Aristotle's Metaphysics, and in particular book Gamma, as an exposition of what philosophy so conceived is.
The following chapters of Bonelli's book are devoted to identifying these three features that philosophy has in Alexander's view, namely a single subject matter, axioms and philosophical theorems. In chapter 2 there is a general account of what Alexander takes philosophy to be as a demonstrative science (e.g. pp. 42, 73, 77): philosophy for him is a science that defines its own object and demonstrates that some essential properties belong to it. Chapter 3 is devoted to the subject matter of philosophy, namely 'being qua being'. Given his understanding of metaphysics as a science, Alexander needs to address the following question: what makes 'being qua being' one subject matter, as required by the Posterior Analytics model for being the subject matter of one science. In Metaphysics Gamma, Aristotle says that philosophy is the science of 'being qua being' (τὸ ὂν ᾗ ὄν) and of the properties that belong to it in virtue of itself (τὰ τούτῳ ὑπάρχοντα καθ' αὑτό). In order to show philosophy to be a demonstrative-axiomatic science, Alexander interprets Aristotle's expression 'being qua being' in a way he believes will make philosophy fit the Posterior Analytics model of science. Alexander takes the particle ᾗ (qua) as interchangeable with καθό, that is, the contracted form of καθ' ὅ. In support of Alexander, Bonelli explains (p. 98) that then the expression ᾑ̂ ὄν must mean that the aspects of being (τὸ ὄν) which philosophy studies are its essential properties, i.e. the properties that account for something's being, and express that in virtue of which an existent exists. In fact Bonelli points out (e.g. pp. 115-122) on Alexander's interpretation 'being qua being' means 'all existents, considered qua existing'. Now, from the Posterior Analytics we already know that scientists produce demonstrations of the possession of essential properties by the objects that each science examines. If philosophy were confined to the demonstration of essential properties of existents, it would directly fit the Posterior Analytics model of science.
But is philosophy for Aristotle confined methodologically to such a narrow sense of demonstration, and confined in content to the essential properties of existents? And is it so confined for Alexander? In the relevant passages of Book Beta of the Metaphysics Aristotle seems not to take a definitive position about this as the context of the discussion is indeed aporetic. It is an open question in that context whether a demonstrative method could or could not be the method of philosophy (and how strictly or liberally the demonstrative method would have to be understood). If philosophy for Aristotle is, as Alexander correctly takes it, about 'all existents, considered qua existing' its subject matter is far wider than the essential properties of substances. So far it is not clear that there is any disagreement between Aristotle and Alexander or any innovation on Alexander's part. The key issue on which Bonelli finds Alexander in divergence with Aristotle then must be methodological. In brief, Bonelli takes Aristotle in Beta to be dismissing the possibility that the demonstrative method is adequate for doing philosophy, and takes Alexander to consider philosophy to be just the field of application of the demonstrative method that Aristotle developed in the Posterior Analytics. So Alexander in Bonelli's reconstruction appears to want to view philosophy as a demonstrative science modelled on the Posterior Analytics. Given that Alexander considers Book Gamma of the Metaphysics as paradigmatic of philosophical method, and in view of the fact that Gamma includes for instance a proof of the principle of contradiction which is neither syllogistic in method nor expressive of the essence of a kind of being in matter, we must assume that Alexander takes the method and the subject matter of the philosophical science to be demonstrative and the essence of being qua being in the widest sense. But in such a wide understanding we could attribute the stance that philosophy is a science even to Aristotle once we realise the aporetic status of his comments in Beta. Bonelli argues that Alexander is producing a conception of philosophy that differs from Aristotle's; an examination of her argument invites us to undertake a more general consideration of their respective conceptions of demonstration, aporia, and other philosophical methods.
Bonelli's book offers us a first rate opportunity and stimulus to engage philosophically with Alexander as the supporter of an original view about the nature of philosophy. Bonelli traces with lucidity and accuracy in Alexander's commentary the steps that lead Alexander from being a faithful interpreter of Aristotle, to proposing an 'Aristotelian' view of his own. In doing so, Bonelli has made a valuable contribution, directing our attention and guiding us through a source still not fully explored in the area of ancient Aristotelian scholarship.1
1. I wish to thank BMCR's anonymous referee for his very helpful comments on several drafts of this review.