The volume offers an edition, with German translation and commentary, of Galen’s commentary on Hippocrates’ De aere, aquis et locis. As this text is preserved only in its medieval Arabic translation, the volume is part of the Supplementum Orientale of the series Corpus Medicorum Graecorum (CGM, based at the Berlin-Brandenburgische Akademie der Wissenschaften), which has been publishing reference editions of ancient medical works since the beginning of the twentieth century. The editor of the text, S., has been studying the reception of the Greek heritage in medieval Islam since his PhD (Humboldt-Universität Berlin, 1965), when he produced an edition of Galen’s De partium homoeomerium differentia, similarly preserved only in Arabic, which was published as the third volume of the Supplementum Orientale in 1970. The publication of the four books of Galen’s commentary on the De aere, aquis et locis can be considered the culmination of S.’s work, where philological rigour and an interest in the history of ideas are interwoven in the reconstruction and interpretation of the text and its transmission. Moreover, it represents a crucial contribution to our understanding of Galen’s thought. Apart from the Arabic version, parts of the commentary, together with the lemmata they refer to, were known from a medieval Hebrew translation, which was in turn translated into Latin, but Karl Gottlob Kühn excluded them from his edition of Galen’s collected works (1821–1833) because he deemed them inauthentic. The entire commentary is now made available to scholars in a reliable textual version, accompanied by a ‘Superkommentar’, as the editor describes it, which discusses philological and historical aspects comprehensively and exhaustively.

The volume opens with an introduction that outlines both the textual tradition of Galen’s commentary and its interpretation in the wider frame of Galen’s oeuvre. S. presents a complete overview of the textual witnesses, ranging from quotations in ancient Greek works to later translations into Hebrew and Arabic, offering a wealth of information to a wide public, from those interested in Oribasius’ use of his sources to editors of Hebrew translations of medical texts in the late Middle Ages. The quotations extant in Greek works, mainly in Oribasius’ Collectiones medicae, are gathered in the appendix to the volume (pp. 291–301), where they are accompanied by the corresponding Arabic passages to allow comparison. To the same end, this appendix also contains Greek passages of other works that Galen quotes in the commentary (e.g. Homer’s or Hesiod’s verses) that can thus be compared with their Arabic versions. The material collected, together with Hippocrates’ De aere, aquis et locis, which Galen quotes in the lemmata, allows S. to analyse the characteristics of the Arabic translation. According to the famous letter of Ḥunayn ibn Isḥāq (809–873) on his translations of Galen’s works, the commentary on the De aere, aquis et locis was translated into Arabic by Ḥubaiš ibn al-Ḥasan al-Aʿsam, Ḥunayn’s disciple and nephew, from Ḥunayn’s previous Syriac translation. S.’s commentary supports Ḥunayn’s words. S. provides as terminus ante quem for Ḥubaiš’s translation the year 872 ce, when the contemporary author al-Yaʿqūbī quoted it (p. xxxix). Drawing on his previous studies on the Syriac and Arabic transmission of Galen’s works, S. turns this reconstruction of the Arabic version of this commentary into a comprehensive interpretation of the translation activity carried out by Ḥunayn and his circle. The main thesis is that Syriac was considered by Ḥunayn to be the valid culture language, while Arabic versions of these Syriac translations were made for a lay audience and mainly by his disciples. S.’s observations on the translation style are varied, including the handling of proper names, the use of explanatory interventions, the peculiarities of the linguistic usage and the features of the technical terminology – I shall point out here his remarks on the frequent presence of hendiadyses, which are commonly understood as explanatory or made to achieve a better precision, but which can also be motivated, as S. argues, by the quest for a better Arabic style, possibly because this was sought for by the (lay) commissioners of the translations (p. xl). With a view to future editions of Arabic translations by Ḥunayn and his circle, S.’s analysis of secondary stylistic interventions by copyists and readers is particularly noteworthy (pp. liii–lvi), as these can be expected to occur similarly elsewhere.

The Arabic translation of Galen’s commentary is preserved by a unique manuscript (Cairo, Ṭalʿat, ṭibb 550), which was first made known to scholars by the prominent Orientalist Fuat Sezgin in his history of Islamic medieval medicine (Geschichte des arabischen Schrifttums, vol. 3 [1970]). Additionally, four Arabic manuscripts preserve the lemmata of Hippocrates’ work; these have been translated and commented before (Hippocrates: On Endemic Diseases [Airs, Waters, Places], ed. by J.N. Mattock and M.C. Lyons [1969]), but have been newly collated for the present edition. The Cairo manuscript preserves an additional short treatise on winds, which did not belong to Galen’s original work, yet is nonetheless included in S.’s volume with the additional collation of its other known witness. In the introduction S. details the value of each witness for the constitution of the text, taking into account extensively the indirect transmission, in a way that is fruitful for future studies on quotations in medieval Islamic medical works and specifically in the Kitāb al-ḥāwī of Abū Bakr Muḥammad ibn Zakariyyāʾ al-Rāzī (854–925 or 935) (pp. lxxi–lxxiii).

An Arabic excerpt of the lemmata was translated into Hebrew by Nathan ben Eliezer ha-Meʾati (active c. 1279–1283 in Rome). This translation, preserved in two manuscripts, is at present unedited, but given its value for the reconstruction of the underlying Arabic text, it has been extensively consulted by S. and included in the critical apparatus, so that his study provides a wealth of information on the translation style of this important scholar, who is also responsible for a complete version of Ibn Sīnā’s Qanūn. Passages of the commentary with the lemmata were extrapolated and translated by a son of Nathan ben Eliezer, Salomon ben Nathan ha-Meʾati, by 1299 in Rome; their single witness, now in Oxford, has also been extensively used by S. Furthermore, he devotes attentive study to the Latin translation of Salomon’s work by Moses Amram Alatino (1529–1605).

S. pays similar attention to the Latin tradition, which preserves an anonymous translation of the Arabic lemmata, edited by Hans Diller in 1932. Diller had no access to the Arabic, so his edition can now be improved textually, as S. suggests for a number of passages (pp. lxxxi–lxxxiii). S.’s detailed analysis of its vocabulary and language offers rich material for future studies on the origin and attribution of this still poorly studied translation.

The philological evaluation of all the above-mentioned textual witnesses is based on a large number of significant cases and provides the basis for the edition. The newly assessed text of Galen’s commentary allows S. to locate it in the later stage of Galen’s activity (p. cxxix) and to study Galen’s practice as commentator, as well as his philological approach to Hippocrates’ text. Therefore, a future edition of Hippocrates’ De aere, aquis et locis would need to include this new witness, as S. points out through the examination of a selection of examples.

By making available a major work by Galen S. has contributed new material that is relevant for scholars of Greek, Arabic, Hebrew and Latin medical texts, and whose richness will hopefully be exploited in the years to come – it suffices to point out that many of the medical works from the Islamic Middle Ages remain unpublished, and S.’s observations on the pervasiveness of contamination within the tradition of Galen’s commentary provide a crucial methodological model in this field.