B.’s investigation of Book E is conducted as part of a project (directed by D. Lefebvre and M. Rashed) aiming to provide new French translations and commentaries for each of the fourteen books of the Metaphysics. It includes a translation, a commentary, a clear and informative critical introduction, an annotated bibliography and two glossaries (a Greek–French and a French–Greek one). His work successfully contributes to fill in a highly lamentable lacuna in the panorama of scholarly production on Aristotle's Metaphysics: the one represented by the lack of a focused treatment of Book E, one which, besides stressing its specific theoretical import in the overall structure of the Metaphysics, provides the most appropriate tools for a critical reading and an appreciation of the book as a single, conceptually autonomous writing.

Both in the introduction and in his commentary, B.’s views take shape and progressively emerge in comparison with a variety of ancient, medieval, modern and contemporary readings of Book E. It is in his discussion of Chapter 1 (in the introduction as well as in the commentary) that the main strengths of B.’s book emerge more distinctively. Therefore in this review, I focus on his analysis of that chapter. First, B. devotes special attention to the issue of the supposed teleological character of the science of being qua being expressed in Chapter 1 of Book E. The author distances himself from a number of Neoplatonic commentators, such as Asclepius (Asclepii in Aristotelis Metaphysicorum libros A–Z commentaria, CAG VI, 2, ed. M. Hayduck [1888]), or modern interpreters like G.L. Muskens (‘The ente qua ens Metaphysicae Aristoteleae objecto’, Mnemosyne 13 [1947], 130–40), who claim that being qua being is to be identified exclusively with God, so excluding any ontologically inferior substance. B. contends that the science addressing that kind of being, if understood only as science of God, would be unable to justify Aristotle's idea that the subject of that science is not just one and divine thing, but ‘(all) the things that are, insofar as they are’. As B. points out, it is not by chance that, in Book E of the Metaphysics, Aristotle refers to being by using a plural noun, τὰ ὄντα, instead of the singular τὸ ὄν (which he employs instead in Metaph. Γ 1.1003a20, where he speaks of ‘being qua being’). To support this view, B. appeals also to Metaphysics Iota (2.1053b20–1), where Aristotle explains that being, as the most universal predicate, cannot be a substance in the sense of a one apart from the many (ἕν τι παρὰ τὰ πολλά), being common to them (κοινὸν γάρ). What is more, if God were the only subject of the science of the things that are qua being, this science would be unable to clarify the meaning of being as ‘categories’ and, especially, the meaning of the category to which all the others ultimately refer: substance (οὐσία).

As B. points out, for these reasons scholars like P. Natorp (‘Thema und Disposition der aristotelischen Metaphysik’, Philosophische Monatshefte 24 [1888], 37–65 and 540–74) and E. Martineau (‘De l'inautenticité du livre E de la Métaphysique d'Aristote’, Conférence 5 [1997], 445–509) have disqualified Book E as inauthentic. His criticism is directed in particular against Martineau's view that Metaphysics E, far from offering a rigorous philosophical treatment of the issue of the science of being qua being, confines itself to offering a ‘theologising’ and ‘crypto-Christian’ picture of that science. Against Martineau's view, B. invites the reader to think of an authentically Aristotelian science of being qua being. For he suggests that this science can be conceived of as a ‘rational theology’, that is, one able to provide sound philosophical reasons for the being of all the things that are, both for what they have in common, i.e. being, and with regards to their specific differences.

The solution proposed by B. departs not only from the idea that the science of being qua being investigates the nature of God, but also from the view (traditionally held by scholastic authors like John Duns Scotus and subsequently endorsed by modern thinkers like Suárez, Wolff and Hegel) that ‘being qua being’ is to be identified with a supposedly abstract, undetermined ens commune. The most remarkable suggestion offered by B. is that the science under examination, as ‘first philosophy’, deals not only with specific objects, but also and especially with the causes (aitiai) of such objects. Assuming that ‘the things that are, insofar as they are’ represent the object that this science proposes to explain (that is, the explanandum), the real subject addressed by the science above is represented by the primary causes that explain their being (that is, the explanans). On the basis of a similar distinction, B. suggests that God and the other divine substances are considered by Aristotle not objects in need of explanation, but causes of specific living beings (such as planets and, perhaps indirectly, corruptible substances).

The most original aspect of B.’s account of Book E resides in the idea that the causes addressed by the Aristotelian theology are not the only primary causes and principles of living beings (contrary to what many ‘creationist’ commentators in the Middle Age, Christian as well as Muslim, used to believe). For the science of being qua being (or the one of the things that are, in so far as they are) also encompasses the study of other forms of causality (that is, the material, formal, efficient and final ones) not identifiable with divine substances. In this light, the universal nature of theology professedly recognised by Aristotle in E 1.1026a30–1 appears to lie not in a supposed capacity to account for any aspect of reality and its complexity, but simply in the fact that theology investigates a form of primary cause. If, as B. suggests, God and the other divine substances are just some among many primary causes, the science of the things that are in so far as they are will appear also, but not exclusively theological.

The profundity of B.’s analysis of Book E owes much to his translation. Although inspired by the need to recover Aristotle's original intentions, in turning several key words from ancient Greek to French, he purposely accords priority to respect for scholarly tradition. By way of example, B. believes that a proper French translation of the phrase τὸ ὂν κατὰ συμβεβηκός would be ‘être par coincidence’ (cf. M.-P. Duminil and A. Jaulin's French translation [2008]) in that such a translation, in his view better than others, seems to convey the idea of a concomitant property or event which, once attached to a given being, produces a new form of being. Despite this reason, B. prefers the translation ‘être par accident’, which has become traditional through the Latin phrase ens per accidens, that has been used for centuries. For a similar reason he translates οὐσία as ‘substance’ and not as ‘essence’.

What is less difficult for B. is the choice of the French word indicating ‘being’. As he observes, Aristotle occasionally refers to ‘being’ through the infinite εἶναι (e.g. Δ 11.1019a4; M 2.1077b17), whereas on other occasions he uses the present participle τὸ ὄν (e.g. Γ 2.1003a33; E 2.1026a33–4; Z 1.1028a10; N 2.1089a7) and even the third person singular ἔστιν (i.e. the present indicative form of εἶναι) (Z 4.1030a21; H 2.1042b25). For all these expressions he employs the French translation ‘être’, intentionally disavowing any possible distinction between ontologically different levels of being (distinctions which B., contrary to authors like Heidegger, believes are not to be attributed to Aristotle).

By showing full command of the ancient, medieval, modern and contemporary literature on Aristotle's Metaphysics, B. not only calibrates wisely his personal views against the backdrop of well-established scholarly trends; he also injects new light on the Aristotelian view of ‘being qua being’ and the science that investigates it. B.’s book provides readers with fertile ground for critical analysis of the key issues contained in Book E, without imposing his personal view or attempting to offer conclusive answers, offering nevertheless clear guiding lines in support of determinate positions instead of others. For these reasons, B.’s work represents an extremely valuable contribution not only to the field of Aristotelian studies, but also for the discipline of metaphysics in general.