The work under review is a masterfully produced edition and translation of the Arabic version of Galen's commentary on book one of the Hippocratic Epidemics. The Hippocratic Epidemics represented "a milestone in the development of medical theory and practice," in particular due to "the often very detailed case histories" found therein that "attracted the attention of numerous commentators and physicians" working in diverse languages (such as Greek, Syriac, Arabic and Latin) over two millennia and across three continents (12). Chief amongst these commentators was Galen, whose own extensive commentary on the work, as well as his judgment over which of the seven books of the Epidemics were genuine (1 and 3), informed the writings of almost all subsequent commentators. In the Arabic tradition alone, "no fewer than fifteen...mostly medical authors wrote texts which were devoted to" the Hippocratic text along with Galen’s commentary.  Uwe Vagelpohl's Arabic edition of Ḥunayn ibn Isḥāq's (d. 873) translation of Galen's commentary on book one (book two is expected soon) is thus a tremendous boon for scholars working on clinical medicine in the Islamicate world.  The Arabic edition of Galen's commentary is also of tremendous importance for classicists for two reasons. "First," as Vagelpohl explains, "[the Arabic version of Galen's commentary] gives us access to a much older stage of the textual tradition than the extant Greek manuscripts." Second, "the Arabic version...played [an important role] in establishing Wenkebach's Greek edition" of the text (15). Finally, by providing the first complete English translation of this seminal Galenic commentary,  Vagelpohl has made it accessible to classicists and medievalists who do not specialize in the history of medicine. This will undoubtedly aid scholars in learning more about the impact of this work on society-at-large, including but not limited to other literary texts produced within the Hellenistic, and medieval Islamic and Latin worlds.
The work comprises an introduction, the Arabic edition with a parallel English translation, supplemental notes and a set of five indices. The introduction does an excellent job of commenting upon the direct manuscript sources used in preparing the edition, as well as the indirect witnesses used for establishing the Arabic text of the Hippocratic lemmata and Galenic comments from later Arabic medical sources. A true gem in the latter case is Ibn Riḍwān's (d. 1068) Kitāb al-fawāʾid (Useful Passages) which alone quotes "[a]lmost a hundred individual passages" from Ḥunayn's translation of Galen's commentary on book one (39). The introduction also contains brief, yet useful, discussions on the textual history of the Arabic translation, as well as how Wenkebach used the Arabic translation in establishing his own Greek edition.  It also provides an excellent analysis of Ḥunayn's translation style, which segues into Vagelpohl's discussion of his own editorial conventions and translation style. A brief discussion of the origin of his project would have been appreciated, though readers can always turn to Peter Pormann's introduction to his edited volume, Epidemics in Context (2012), to learn more about it.
The Arabic edition and accompanying critical apparatus is brilliant. Vagelpohl explains in the introduction why he sticks to a purely "positive apparatus" (58). Since the original Arabic translation only exists in one complete manuscript, Vagelpohl has chosen to highlight all variants attested in the primary sources whenever they occur. In addition to noting such variants, the critical apparatus also cross-references cases where the manuscript reading is confirmed (whether verbatim or not is also indicated) in other Arabic primary sources (for example, Ibn Riḍwān's Useful Passages and the Arabic Hippocratic Aphorisms). It also refers to cases where the Arabic text is missing sections found in the Greek version of Galen's commentary. The notes at the end of the book, on the other hand, discuss more deeply the differences between the Arabic and Greek traditions of the text. Here, Vagelpohl notes all passages where the Arabic text adds, omits, paraphrases, interprets, or transposes the Greek text. These notes provide extensive material to examine Ḥunayn's translation style, albeit with the caveat that some of these differences may be due to the problematic nature of the extant Greek manuscripts. Nonetheless, Ḥunayn's various amplifications, definitions and, at times, interpretive paraphrases of Galen’s commentary reveal much about how he and his workshop balanced their commitments to being faithful to the original Greek, with their concern for medical accuracy and Arabic style, as well as the needs of their readers/patrons. As a recent scholar puts it, "[T]hey aimed at expanding their base text for the purpose of usefulness, instruction, and perhaps also reading pleasure, at least as much as the Greek source would allow." 
The English translation is very good. The specific stylistic choices have been explained by Vagelpohl in the introduction (60-61). The translation is very readable and remains faithful to the meaning (and, at times, style) of the Arabic text. Some of the specificities of Arabic style are brought out nicely in the footnotes, which often record more literal translations of Ḥunayn's Arabic. The Arabic style can thus, theoretically, be compared to Galen’s Greek style by classicists who do not know Arabic, albeit only in a limited manner.
The author, however, has made some odd choices in the translation that obscure the Arabic style far more than dictated by English grammar. For example, the translation reads (83): "He frequently mentioned in his book...," instead of: "He mentioned in many passages of his book..." The advantage of the latter is that the Arabic phrase in the next sentence (fī mawḍiʿin mawḍiʿin) could then be rendered as, "in each passage" instead of "in each (relevant) passage." Similarly, Vagelpohl translates a well-known Arabic phrase (fa-mā adrī) as, "I have no idea" (393), instead of simply, "I do not know," or the more evocative, "How do I know." Also, in a few instances, Vagelpohl's translation could be improved to convey better both the meaning and style of Ḥunayn's prose. For example, the first sentence of Galen's commentary on II.8 is rendered thus: "It often happens that bad waste products are excreted from the bottom while the stomach and the bowels are healthy and without disease; rather, the waste products the whole body is cleansed of descend to them by being expelled by the nature towards these places so that they pass through and emerge from the body" (199). A better translation would have been: "It often happens that bad waste products are excreted from the bottom while the stomach and bowels are healthy and without disease; however, the wastes descend to them, for the entire body is cleansed by nature expelling (the wastes) to these places in such a way that they pass through and emerge from the body."  These brief examples, however, do not lessen the overall quality of the translation.
Finally, there are five indices, including a fabulous "Greek-English-Arabic glossary" (703-732). The glossary is a wonderful resource for scholars interested in Graeco-Arabic studies and complements the existing Greek and Arabic Lexicon and the online resource, Glossarium Graeco-Arabicum, by covering medical terms across all letters of the Greek and Arabic alphabet. There is also an additional "Index of Arabic words" (610-677). To this reviewer, however, this index is poorly constructed and unnecessarily long. It is difficult to know why all occurrences of simple words such as aḥad (one) or waṣafa (to describe) have been indexed. It would have been much more prudent to prune this index by focusing on important concepts and terms of the text, as has been done for the English index.
In conclusion, Vagelpohl has produced a wonderful edition and translation of a key medical text and commentary that should spark the interests of classicists, Islamicists and Latinists alike.
1. Bink Hallum, "The Arabic Reception of Galen's Commentary on Hippocrates' 'Epidemics'," in Peter Pormann, ed., Epidemics in Context: Greek Commentaries on Hippocrates in the Arabic Tradition (Berlin: De Gruyter, 2012), pp. 185-210.
2. See, for example, Cristina Álvarez-Millán, "Practice versus Theory: Tenth-century Case Histories from the Islamic Middle East," Social History of Medicine 13 (2000): 293-306; idem, "Disease in tenth-century Iran and Irak according to al-Rāzī's Casebook," Suhayl 14 (2015): 49-88; and Peter Pormann, "Case Notes and Clinicians: Galen's Commentary on the Hippocratic Epidemics in the Arabic Tradition," Arabic Sciences and Philosophy 18 (2008): 247-284.
3. An earlier German translation was published along with Wenkebach’s Greek edition; Galeni, In Hippocratis Epidemiarum libr. I comm. III, ed. E. Wenkebach; libr. II comm. V, transl. F. Pfaff, Corpus Medicorum Graecorum 10, 1 (Leipzig and Berlin, 1934).
4. Detailed discussions on these topics can be found in his earlier publication; Uwe Vagelpohl, "Galen, Epidemics, Book One: Text, Transmission, Translation," in Pormann, ed., Epidemic in Context, pp. 125-150.
5. Oliver Overwien, "The Art of the Translator, or: How did Ḥunayn ibn ʾIsḥāq and his School Translate," in Pormann, ed., Epidemics in Context, pp. 151-169, 169. Also, see Uwe Vagelpohl, "In the Translator's Workshop," Arabic Sciences and Philosophy 21 (2011): 249-288.
6. The Arabic text of this passage contains some problems (198, 7-10). For example, the stomach and intestines are referred to in dual form once (tanḥadir ilayhimā), and in all other cases as non-dual plurals (e.g. lā ʿilla fīhā, or ilā tilka al-mawāḍiʿ). Similarly, in the last phrase, wastes are either being referred to in the singular, or the bihi should be bihā. Vagelphol notes that these (problematic) elements are all amplifications of the Greek text (532).