In the last 50 years interest in Plotinus has been growing among historians of philosophy, classical philologists and philosophers: starting with R. Harder and W. Theiler, followed in Italy by V. Cilento and in France by É. Bréhier, the Enneads has become the object of study for many a valiant scholar. All this philological care on Plotinus culminated in the magisterial critical edition by P. Henry and R. Schwyzer, the first to provide a sound and trustworthy text. Meanwhile, the importance of Plotinus' position within the Western philosophical tradition was recognised and strongly asserted by historians of philosophy, and in turn his presence has been ever more felt within contemporary philosophical debate. In particular in the last 30 years many new translations have been published of the entirety of the Enneads as well as of single treatises: these translations are accompanied by an often lengthy introduction and a commentary. The thought of Plotinus and the text of the Enneads have received an attention that few ancient authors have ever had. France has undoubtedly been the main centre of Plotinian scholarship: the late P. Hadot started and directed a series of commentaries on single treatises published by Les Éditions du Cerf, and valuable commentaries have appeared in a series published by La Librairie Philosophique Vrin, as well as a new French translation of the Enneads with a brief commentary for each treatise published by Flammarion. A team of scholars, including L. Brisson, M.-O. Goulet-Cazé and D. O'Brien, led by the late J. Pépin, have produced an indispensable ensemble of studies on the Vita Plotini by Porphyry, which includes a revised Greek text followed by notes (1992).

This new edition is the first volume in a series that will provide a new critical edition of the Enneads followed by notes that will deal with both philological and philosophical matters. Following what has become almost the standard in France, the treatises will not be presented in Porphyry's editorial order, but in their chronological order. This choice is certainly understandable but not completely uncontroversial, given the fact that Porphyry's intervention probably went further than just rearranging the order of the treatises: the case of the so called Großschrift, which has surely not been proven to be just a construction by Harder, as N. suggests (p. lii n. 1), is an example. However, the advantages are probably greater than the disadvantages, as this approach allows from the start a better grasp not only of the progress and changes in Plotinus' thought – provided that such things can be detected in his speculation – as well as a clear idea of what can be defined as his unsystematical way of proceeding. The treatises are very probably the result of discussions within the circle of friends and acolytes of Plotinus and as such they display a certain extemporary nature.

The first volume provides a new edition of the first treatise, I 6 in Porphyry's order. The volume can be neatly divided into two parts: the first part (pp. xi–ccxcvi) by N., the second (pp. ccxcvii–cccxxix and pp. 1–69) by N. and A., except pp. ccli–ccxcvi on the history of the text by F. In the second part the section in Roman numerals contains the introduction to I 6, while the section in Arab numerals contains the text, established by F., the facing French translation by N. and A. and finally the exegetical notes.

The first part can be further subdivided into two sections: pp. xi–xcvii provide an introduction to the work and thought of Plotinus, while pp. xcviii–ccl contain an essay on the notions of ὑπόστασις and τάξις. The first section gives information about the life of Plotinus and the more characteristic points of his speculation in its development and in relation to the previous Greek philosophical tradition as well as with Gnosticism. N. underlines (pp. xlix–lix), rightly, that Gnosticism had a considerable role in the shaping of Plotinus' speculation in that, because of its similarities and at the same time its fundamental differences with what he perceived to be the ‘orthodox’ version of Platonism, it provided Plotinus with a polemical object, giving him the motive for composing some of his treatises.

The essay on the two opposing notions of ὑπόστασις and τάξις represents the most original and, in my view, interesting section of part one: it situates Plotinus' speculation in relation to the following Neoplatonic tradition, thus helping us to understand his role in the formation of this tradition. N. proposes that between Plotinus and Proclus a fracture can be detected in the terminology that refers to the most fundamental realities of the world: where Plotinus uses ὑπόστασις, Proclus uses τάξις or other terms such as σειρά conveying the same meaning. N. (pp. xcvii–cxiii) eliminates once and for all a lingering prejudice among scholars, namely that the technical use of the word ὑπόστασις should be ascribed to Porphyry: he shows that the term was already being used in a technical way by Plotinus himself. Having established this, he proceeds to analyse the use and the meaning of τάξις in Proclus. The difference between the two terms lies in that the Plotinian term collapses into one rigid ontological category realities that are disparate in their nature, while Proclus' term is able to account for these differences providing a more flexible conceptual container (p. cxcv). In other words, where ὑπόστασις flattens everything into one category, for example Soul, not accounting for the substantial differences between the World-Soul and the various individual souls, τάξις respects these internal differences and avoids mixing them up into one single ontological category. Thus, in fact, Proclus rejects the idea of ὁμοουσία of all members of a same category implicit in the notion of ὑπόστασις, to underline through the notion of τάξις that if disparate things, such as the World-Soul and the individual souls, share something in common, this is not because they are of the same identical substance (ὁμοουσία), but because they all resemble one and the same archetypal model. This perspective represents the principle of analogy ἀϕ᾽ ἑνός, namely a link based on resemblance to a common model rather than on identity of substance (pp. cxcff.). Having established this, N. shows that this change in terminology, and more importantly in perspective, is not due to Proclus, but rather to Iamblichus, from whom the former inherited it. N. then goes on to discuss some of the main characteristics of Iamblichus' thought in comparison with Plotinus'.

The critical apparatus not only gives the various different readings but also a most welcome list of parallel passages in the authors before and after Plotinus. This is particularly important because reference to quotations of Plotinus in authors like Psellus facilitates the study of the reception of the Enneads in the Byzantine Middle Ages as well as in the Italian Renaissance. The notes give both philological and philosophical guidance throughout the text, which is something that previously could only be found in Cilento's Italian translation.

The present volume is truly admirable and arouses great expectations for the volumes to come.