Medical Epitome

This chapter examines John’s Medical Epitome. The focus here is on the first four of its six books. In contrast to the established view that this work was intended for physicians, it is argued that it was primarily written for philiatroi, intellectuals who were deeply interested in medicine, but not practising physicians themselves. The Medical Epitome, unlike John’s other two works, mainly consisted of material from earlier sources. The analysis of the text starts with a close reading of John’s proem and a discussion of the background of his dedicatee, the Byzantine statesman Alexios Apokaukos. It then shifts to an examination of the work’s structure with the aim of emphasizing John’s intentions in putting together his material. The analysis proceeds by way of a number of case studies focusing on diagnosis and therapy, and goes on to show that John intentionally condensed his material, removing specialized advice, so as to make it appeal to non-expert readers. Thus it is shown, for example, that the absence of details on invasive operations is consistent with the character of his intended readers, who were only able to use non-invasive techniques, such as phlebotomy and arteriotomy. Finally, the particular attention John paid to differential diagnosis, especially as regards eye affections, which is often supplemented with his own advice, is highlighted.

On Urines

This chapter focuses on the group of illustrated case histories narrated in John’s On Urines. An introductory section on clinical narratives provides the necessary background and emphasizes that John’s clinical accounts had no counterpart in the Greek-speaking world after Galen. It is argued that John’s case histories could function as didactic material for readers with specialist knowledge, while at the same time they could be used as self-promotional material to impress the specialist and non-specialist alike with the physician’s skills in diagnosing, prognostication, and his self-proclaimed ability to treat his patients successfully. The largest part of the chapter focuses on physician–patient encounters. It explores the significance of John’s acquaintance with the patients and the patient’s socio-economic background, but also their experience of the physician’s professional expertise. It is shown that the visual aspect of the urine vial constitutes a recurrent element of symbolic significance, which helps the patients decipher the physician’s actions and shows the latter’s awareness of the need for individualized patient care.

On Urines

This chapter concentrates on John’s uroscopic theories as presented in his On Urines. It starts by examining the structure of the work, showing John’s intention to systematize knowledge on the subject by dividing his treatise into four large thematic areas, i.e. introductory details, diagnosis, aetiology, and prognosis, thus presenting a general-to-specific approach in each section. The analysis then shifts to John’s theories on the various stages of human digestion, which had remained undisputed for centuries. It is shown that John is eager to present his own understanding, especially on the role of the liver. John’s own observations are also evident in his discussion of the different colours of urine thanks to the extra explanatory information he provides in this respect, especially on how to differentiate between various colours. The last section focuses on John’s urine vial, which although identified as an important feature of his original approach by earlier scholars, was never fully contextualized in light of a holistic reading of John’s work or of the development of other, non-Byzantine, medieval theories on the subject. Consequently, it is argued that John’s most original contribution is the introduction and detailed definition of eleven subdivisions in the urine vial compared to the three areas traditionally identified.

Conclusion

The last chapter aims to sum up the main findings from the study of John’s works, as detailed in previous chapters. In particular, it highlights John’s original contributions to medicine in the context of early Palaiologan intellectual circles and the wider Mediterranean milieu. It also provides plenty of examples of John’s outstanding reception in the Byzantine world and in Renaissance Europe, including the early-sixteenth-century editions of his corpus. In this respect, some specific examples are given, such as the first translation of On Urines by Ambrogio Leone of Nola with reference to its subsequent influence throughout Europe, the publication of the complete Latin translation of the Medical Epitome by Henry Mathys, and the early printed Greek edition of On Psychic Pneuma by Jacques Goupyl.

Medical Epitome

This chapter deals with the last two books of the Medical Epitome, which focus on pharmacology. John’s material presents a unique amalgamation of earlier Greek and Byzantine sources with recently introduced Arabic pharmacological lore. It is argued that, unlike the first four books, the last two books may be addressed not only to philiatroi but also to the expert reader, since they provide a revision of the subject that was much needed in late Byzantium. Special emphasis is given to the role of experience (peira) in the pharmacological part, which, unlike in the first four books, plays an important role in the selection process here, as it is often highlighted by John himself. The analysis then shifts to John’s sources, including Galen’s On the Composition of Drugs According to Places and also the Greek translation (Ephodia tou Apodēmountos) of the famous medieval Arabic medical text by Ibn al-Jazzār Zād al-Musāfir wa-Qūt al-Ḥāḍir, more commonly known by its Latin title Viaticum. A particular section is devoted to John’s adaptation of Arabic pharmacology, including his many recipes for sugar-based potions and his reference to oriental materia medica. In the first case, a potential unedited source ascribed to an otherwise unknown author, one Chariton, is identified. As regards oriental ingredients such as zedoary, galangal, cubeb pepper, and various kinds of myrobalan, a further contextualization is attempted by making use of other contemporary non-medical sources, especially merchants’ accounts, which show that many of these substances were readily available in Constantinople, although usually at a high price.

Introduction

This chapter provides introductory sections on Byzantine medical literature and the historical and intellectual setting in which John and his corpus should be placed, including the early Palaiologan revival of knowledge. A special section provides a survey of previous studies on John’s works and identifies the limitations of earlier scholarship, showing that his medical corpus has been inadequately evaluated. It then focuses on John’s biographical details and his works. Particular attention is paid to the dating of John’s works and his use of language. Moreover, new data is provided on the office of aktouarios in late Byzantium showing that, contrary to what has been suggested in the past, there is not sufficient evidence to support the idea that John had a permanent post as court physician.

On Psychic Pneuma

This chapter offers a critical examination of John’s third medical work, On Psychic Pneuma. The first section deals with John’s audience, contextualizing his relationship with his dedicatee, Joseph Rhakendytes. John describes the psychic pneuma as the vehicle and first instrument of the soul; consequently, the purified state of this pneuma, achieved through an appropriate regimen, is essential to keeping Joseph’s bodily and spiritual health in good condition. It is then shown that, unlike earlier Greek and Byzantine theories on human physiology in which authors identified three kinds of pneumata, John identified four distinct pneumata: in the stomach, liver, heart, and brain, respectively. Furthermore, John introduced an innovative theory in which each of the four pneumata is correlated with two primary qualities (unnamed, ‘gastric’ pneuma: cold and moist; natural pneuma: warm and moist; vital pneuma: warm and dry; psychic pneuma: cold and dry). A close reading of John’s text unveils the major importance that is given throughout the treatise to the psychic pneuma, which is dispersed throughout the body via the nerves and is responsible for sensory and motor activities. Any disturbance in the quality, for example, of the psychic pneuma may affect its flow and can thus be a cause of impairment. Finally, it is pointed out that John made a direct connection between the quality of pneuma and one’s daily regimen, including diet, physical exercise, bathing, and sleep, thus providing a systematic introduction to the qualitative change in pneuma as an object of treatment.