Of Galen's dozens of surviving works, that on Health (known to scholars by its traditional title in Latin, De sanitate tuenda) is one of the most interesting to modern readers. Its discussions of exercise in the gym, the qualities of foods, the various types of wine and the idea of a daily health routine are relatable to modern life, even if the details jar at times. Health is also the only Galenic treatise that includes substantial discussions of infancy and old age. For all these reasons – because it sheds light on the everyday world of its admittedly elite, urban audience – it is especially valued by historians. Its main subjects are exercise, fatigue, diet and massage, beginning with the care of the infant and following its putative (male) subject through adolescence, adulthood and old age.

A critical edition of the Greek text has been available since 1923, when K. Koch's edition was published in the Corpus Medicorum Graecorum. Until recently, the only English version was R. Green's translation of 1951, which is, for many reasons, of limited use to scholars. It was an important step forward when I. Johnston's translation was published, as volumes 535 and 536 of the Loeb Classical Library series, in 2019. Both Johnston's version and that of S., a volume in the series Cambridge Translations of Galen, include a great deal of apparatus of value to scholars. S. provides references to pagination in both K. Kühn and Koch; and, in addition to a general introduction and notes on the text, he offers several appendices and indexes. These include a Greek word index, an English–Greek glossary, an index of names and an index locorum as well as a general index. His version lacks the Greek text on facing pages supplied in the Loeb series. Scholars will want to consult both S. and Johnston when working with this treatise.

Besides Health, this volume includes the shorter treatise Thrasybulus, also known to scholars as To Thrasybulus, or whether health belongs to medicine or gymnastic training. This is an argumentative essay, originally a transcription of a speech Galen gave in response to a ‘problem’ (question posed randomly for discussion) in a debate, in which he makes the case that medicine as a discipline includes preserving and maintaining health as well as therapy and that gymnasium trainers, who work largely with athletes, are in no way the equivalent of doctors. Most of this treatise is a theoretical discussion of the boundaries of the field of medicine; but it is most interesting to historians and non-specialists for its exposition of Galen's hostile view of athletes. Its contents are similar to those of Galen's treatises On the art of medicine and On the constitution of the art of medicine, but its specific focus on the idea of a science of health also connects it to Health; Galen cites Thrasybulus frequently in the latter treatise, and the two works seem to have been written at nearly the same time. (The Loeb series also publishes the two treatises together, along with Galen's more light-hearted treatise on The exercise with the small ball.) A translation of Thrasybulus appeared among the treatises collected in S.'s 1997 Oxford World Classics volume, Galen: Selected Works (unfortunately out of print) and has been thoroughly revised for this edition.

Among topics discussed in the introduction, perhaps the most noteworthy is S.'s original and persuasive argument about the date of Health, placing it late in Galen's career, rather than in the reign of Marcus Aurelius, the date accepted by scholars up to now. It is unfortunate that considerations of time and space seem to have precluded a discussion of the treatise's substantial Nachleben; it was highly influential through the Renaissance and important to such English physicians as Thomas Linacre (whose Latin translation is printed in Kühn's 1821 edition), as no easily accessible discussion of that subject is known to me (or cited in the text).

This is, however, my only criticism of an invaluable scholarly tool. Like all volumes in the Cambridge Translations of Galen series, it opens up the black box of Galen's works to scholars in fields outside of Classics and to Classicists whose projects preclude exhaustive, time-consuming struggles with the Greek text.