John ‘Climacus’ (‘of The Ladder’), abbot of St Catherine's Sinai, probably in the later sixth century, thought that the sick naturally rejoiced to see a physician even if they derived no benefit from the visit. He certainly admired physicians himself. He also knew what they should be about. ‘Procure, you marvellous man’, he advised, ‘plasters, desiccants, eye salves, draughts, sponges, anti-emetics, lancets, cauteries, unguents.’ But then he showed, in his treatise To the shepherd, how such a list could be applied within the monastery for healing damaging passions. ‘A plaster is the cure of the visible, that is, bodily, passions … a desiccant is a stinging dishonour which heals the putrefaction of self-conceit … a sponge is therapy and refreshment after bloodletting or surgery, through the physician's gentle, soothing and tender words to the patient … cautery is a rule and penance for repentance’, and so on. Why this elaborate, indeed baroque conceit? The short answer is that John took it over from the Apostolic constitutions in which the bishop's disciplinary action is figured as medical therapy. The longer answer is that it derives from the Gospels: ‘those that are well have no need of a physician, but those who are sick … For I came not to call the righteous, but sinners’ (Matthew ix.12–13; Luke v.31–2). The metaphor of treating sinners with spiritual medicine following the example of Christ as the ultimate physician is as old as the Gospels, and it has well-known non-Christian analogues such as the psychagogy of Hellenistic philosophy. ‘Christ the physician’ (of souls) was taken up and elaborated by the Church Fathers, first by Ignatius, then by Jerome, and most influentially by Augustine, who imaged the whole of humanity as a patient. It is easy to see why such imagery appealed. Medicine offered a model of authority over the mortal body which could be transferred to the immortal soul. It also exemplified the flexible application of a few essentially simple fundamentals in ways that could be precisely tailored to the perceived defects of both individuals and groups.

This longer answer is incomplete and misleading. It implies that detailed medical knowledge, such as displayed by John Climacus, was window-dressing. Yet in ancient medicine, especially of the Galenic kind, the state of the body was intimately bound up with the state of the soul and traffic between soul and body was two-way. Medicine shaded off, moreover, into ethics and philosophy generally. The use of medical tropes in apparently non-medical contexts was thus not merely metaphorical, a juxtaposition of the dissimilar and separable. Therapy of the soul was not like medicine; it was medicine – albeit of a distinctive kind with its own purposes. Such is the conclusion of a chorus of recent scholarship – a chorus that Jonathan L. Zecher, already an authority on John Climacus, joins and indeed with this excellent new book may be said to lead. His purpose is to go well beyond simply identifying medical terms and analogies and to ask: why did late antique or early medieval monastic writers use so much medicine, and with what effect? What did the invocation of medical learning enable them to do that plain speaking, or analogies drawn from domains such as pedagogy, rhetoric or athletics, did not? The answer given here, elaborated with great attention to the minutiae of the texts, is that it gave them, first, a ‘logic of practice’ (diagnostic and therapeutic techniques derived from a theory of human nature with the aim of restoring health) and, second, a model of expertise and trustworthiness.

We of course have only the texts, but Zecher's purpose is to treat these as windows, however partial and oblique, onto aspects of ‘spiritual direction’ of young monks by their seniors, presumably undertaken orally for the most part, though also by letter. Spiritual direction is taken to include discipline, confession and the imposition of penance, although the sacramental aspect is not the main focus here, and a wider evaluation of the thoughts and actions of the younger monk are in play, whereby he (always ‘he’ in this context) becomes an object of knowledge to the ‘confessor’ figure but his subjectivity is also refashioned in the process (p. 10).

The principal witnesses are the ‘long fourth-century’ Evagrius Ponticus, John Cassian and Basil of Caesarea, with John Climacus as a chronological outlier; but the choice of ensemble is eminently defensible in terms of their lasting influence on medieval monastic thought. Medical aspects of the writings of each are examined at length, in a way that builds on but surpasses existing scholarship, first under the heading of practice, then under that of expertise. Thus, we sit beside Evagrius as he works out a symptomatology of dreams; beside Cassian as he accounts for nocturnal emissions (this chapter is worth it alone for Zecher's diagnostic flow chart of such occurrences); beside Cassian again and Climacus as they anatomise passions (a comparable highlight here being Climacus' family tree of the stomach's deplorable ‘daughters’, such as ‘buffoonery’). One striking theme, which might have been brought out even more fully, is how often the demons’ perceived probing of a soul's or body's defences mirrors the diagnostic strategies of the spiritual director. In part ii, Basil joins the group as authors are shown variously laying claim to expertise and authority in spiritual direction, most severely with Climacus’ deployment of images of imprisonment and amputation for refractory monks.

Since this is a book for scholars of early Christianity more than for historians of late antique medicine (though they should read it too), it starts with an outline of ancient medicine. That is done with great skill and clarity. The medical background can, however, be skipped by readers avid for the spiritual because relevant sections of it are helpfully cross-referenced in the chapters on monastic authors. Throughout, Zecher shows his mastery of the primary texts of ancient medicine and philosophy and of medieval monastic spirituality. Well able to nuance or correct such eminences as Foucault and Peter Brown, he commands a substantial secondary literature, both of his subject and of appropriate models from other domains (though is the ‘biopsychosocial’ model much of an advance on ‘holistic’ medicine?). The chapters are argued and structured with exemplary clarity. Still, part i is not for those predisposed to buffoonery and, if I had been the book's editor, I might have suggested putting the less intricate part ii first as a way into the subject. Overall, it is hard, none the less, to see how the book's task could have been more persuasively accomplished. All future discussion of its theme must start here.