The present volume is part of a larger enterprise dedicated to editing and translating the entire collection of 52 epistles written by the Brethren of Purity, an esoteric brotherhood active in tenth-century Iraq. While many details concerning the authorship, identity, and ideological affiliation are still unclear, the epistles furnish valuable insights into one of the various strands constituting the intellectual universe of the pre-modern Islamic world. Notably, they are neither purely religious nor exclusively philosophical, but defend a perfect harmony between the two spheres. In order to attain felicity, the Brethren maintain, man must follow the twofold path of religious law and philosophical sciences, the sine qua non of purifying body and soul and grasping the truths underlying reality (ḥaqāʾiq al-mawjūdāt). Accordingly, their writings aim to provide the reader with the corpus of knowledge required to pursue this goal. As a result, they cover a broad range of subject matter which, notwithstanding its idiosyncrasies, is considerably influenced by the Alexandrian tradition as well as contemporary philosophy (falsafa). The epistles have often been described as a populist scientific encyclopaedia aspiring simultaneously to comprehensiveness and accessibility.

With this background, the decision of the Institute of Ismaili Studies (IIS) to edit and translate this compendium is very welcome. It permits the study of the Brethren's thought even without the mastery of Arabic. With Epistles 32–36 the present book embraces the first fraction of those treatises (E32–41) that deal with soul and intellect, a core topic of the brotherhood's teachings situated at the interface of cosmology and anthropology. On their account, not only is the entire universe governed through the mediation of Soul by Intellect, but also human beings by virtue of their individual souls partake of intellect and, thus, of the means to accomplish their ultimate goal: the acquisition of knowledge and, hence, felicity. This well-known Neoplatonic motive pervades E32–36 which: first, tackles the intellectual principles of the cosmos: the One, Intellect, and Soul (E32–33); second, establishes a link between the universe – the “macroanthropos” – and the sublunar sphere of man (E34); third, moves on to the human intellect and its specific object, the intelligible (E35); and, fourth, addresses the heavenly cycles and revolutions, i.e. those principles which affect the material constitution and behaviour of the physical world, including the bodily mixtures (humours) of its animated inhabitants (E36).

In accordance with the other volumes of the series, the book is opened by general editor Nader El-Bizri's foreword. The first main part embraces the translations of the epistles, preceded not by a common but by individual introductions instead. While at first glance this procedure may appear somewhat odd, it is due to the fact that several scholars collaborated in the production of this volume: Paul E. Walker is responsible for E32 (a and b), 33, and 35; Ismail K. Poonawala and David Simonowitz for E34; and Godefroid de Callataÿ for E36. The second main part of the volume encompasses the editions prepared by the respective scholars. Inserted between the two main parts are a select bibliography (of extant editions, sources, and secondary literature), subject index, index locorum, and Arabic glossary. Although, unfortunately, the translations and editions are not arranged on facing pages – a general feature of the series – overall the volume presents a useful tool facilitating not only acquaintance with the texts but also with a representative segment of the copious scholarship. Yet, despite the undeniable merits of the series in general and this volume in particular, there are a number of peculiarities which require additional remarks.

Among other things, the series proclaims to offer a “critical edition” (beyond the title, see for instance p. xix) of the epistles. However, it is not clear either from El-Bizri's general foreword or from the individual introductions why and how the 19 manuscripts (out of more than 100 known copies) selected by the IIS should be suited to grant a sufficiently solid basis for a critical edition. The only indication to be found in the foreword is a reference to these manuscripts’ early dating (p. xxi, n. 3), but as is well known, more recent copies are often closer to the original than more ancient ones. Moreover, as the scholars who collaborated in the production of this volume consistently underscore, it is impossible to establish a stemma on the basis of these nineteen manuscripts (or rather thirteen [Walker, p. 1 and 109; Callataÿ, p. 157] or fourteen [Poonawala, p. 69] – without further explanation of this discrepancy). This raises the question of why the IIS did not attempt to get hold of additional copies, particularly since some of them “could have been easily obtained”, as Poonawala observes in the introduction to E34 (p. 68, n. 45).

Moreover, although there is nothing wrong with the IIS's decision to commission E32–36 to several scholars, the reader will be surprised by the disparity of treatment concerning all essential aspects: editorial standards, accuracy of translations (terminology), extent of annotations, and diligence of introductions. Whereas, with respect to these factors, the treatment of E36 is excellent (particularly the meticulous explications of the underlying astronomical theories), other cases are rather disappointing if not utterly misleading. This is especially striking in the case of E35, a key text within the frame of the Brethren's doctrine. Nonetheless, the introduction offers only a couple of pages dedicated to the treatise's content, lamenting primarily the obscurity of the epistle's “message” and wondering “why it exists” (p. 111); there are hardly any explanatory annotations to the translation; and several renderings are quite debatable (see for instance the technical terminology in chapter 15, p. 132 with n. 36, e.g. taṣawwur translated as “imagination” instead of “concept formation”; iʿtibār rendered as “expression” instead of “intellectual contemplation”). On the whole, the impression resulting from working with this volume is somewhat mixed. Given the significance of the series, this is deplorable; it would be desirable for the IIS to put more emphasis on elucidating their editorial principles and, particularly, on ascertaining the homogeneity as well as quality of the individual contributions.