The medical landscape of the second century CE was in many ways dominated by an epistemological dispute that had emerged in the Hellenistic period. The principals in conflict were the ‘Rationalists’ and ‘Empiricists’ who contested the proper methods of discovery and limits of knowledge acquisition. The young Galen studied in the shadow of authorities from both ‘sects’ (haireseis), and so it is within this fractious milieu that his epistemological commitments, syntheses and self-promotions must be understood. This collected volume brings together a group of leading Galenists who probe the physician’s approach to the respective role(s) of reason and experience within the medical method. The 11 chapters herein (plus an introduction by Jim Hankinson, covering the state of the question over the past 40 years) provide fresh and important analyses of these questions as they play out across a wide range of Galen’s writings and practice. Despite this variety, one of the volume’s admirable strengths as a collection is its explicit cross-referencing and implicit dialogue among chapters. The result is a considered and coherent whole representing a substantial contribution to our finer understanding of how Galen attempted to ‘synthesize’ the methodologies of the rival medical sects of his day. Given restraints of space, this review compasses only those contributions which stood out to this particular reader, though all are estimable in their treatment of the materials.

Inna Kupreeva (Chapter 2) sequentially anatomizes in a crisp and helpful way the major epistemological issues at stake within the Rationalist/Empiricist debate as conveyed by Galen in On Medical Experience, the earliest (c. 165/6 CE) of his several works on this sectarian conflict (most of which survives only in Arabic). Especially useful is Kupreeva’s treatment of the soritical argument Rationalists deploy to deny Empiricist claims to ‘technical’ knowledge. Among other points of clarification, Kupreeva illuminates the major elements of the Empiricist programme that Galen is fundamentally on board with, particularly his admiration for their constancy of methodological application (by contrast to the slipshod commitments of many practising Rationalists). Jim Hankinson’s contribution (Chapter 3) extends the focus on Galen’s thinking about the correct relationship between experience and reason in the context of ‘reasoned experience’ (peira diōrismenē) as the appropriate method of medical discovery. Empiricists lack any justifiable means of uncovering (new) compound drugs: a major problem. Hankinson details the ways in which ‘reasoned experience’ leads the practitioner to establish, from singular test cases, the causal powers inherent in particular substances, thus permitting a reasoned approach to compounding drugs which is confirmed by experience.

Peter Singer (Chapter 6) raises the especially interesting question of ‘inexpressible experience’ within the clinical setting. Rather than concentrating on the patient’s experience, a recent focal point of medical history, Galen is concerned with the limit of the physician’s ability to communicate verbally the kinds of fine-grained distinctions between perceptual phenomena that are critical for the expert practitioner to recognize (for instance, minute discrepancies in the pulse). Importantly, theoretical frameworks provide direction for the practitioner that make direct perception legible (again, the pulse is helpful); in this way perceptual experience is significantly guided by logical structures, pointing out a substantial gap between Empiricist and Rationalist accounts of experiential knowledge. Orly Lewis (Chapter 7) centres Differences of Pulses to unpack Galen’s methodological disputes with his rivals (here, the popular Archigenes) over matters wherein there existed considerable terminological and ontological overlap. Galen accuses his competitor of sloppy application of terms for different classes of pulse, but this failure ultimately stems from Archigenes’ ignorance of the correct procedures for the classification and division of phenomena (as articulated in Galen’s On the Doctrines of Hippocrates and Plato). For Lewis, Galen’s critique reveals not only his own methodological habits, but casts an important light on alternative modes and models of categorization employed by his contemporaries. Lewis’ chapter also neatly illustrates Singer’s contention that proper terminological descriptions are critical for establishing horizons of expectation whereby practitioners might discern distinctions in perception that are too nuanced to express verbally.

Katerina Ierodiakonou (Chapter 8) shifts our attention to Galen’s notorious philosophic eclecticism, taking up his engagement with Platonic, Aristotelian and Stoic theories of optics as a case study. In this chapter Ierodiakonou ably demonstrates the method whereby Galen upholds the Platonic account of vision (delineated in the Theaetetus) through a somewhat mercenary ‘enrichment’ via Stoic theories. That is, Galen is happy to strip particular elements from Stoicism (here, the cognitive discernment of physical change within the eye), while leaving behind the bulk of the Stoic cardiocentric framework, which Galen openly despises in light of his experience and experiments upon the brain and nervous system, that grounded it. David Kaufmann’s contribution (Chapter 9) also deals with Galen’s eclecticism, but turns our attention to the relationship between experience, reason and his ‘moral epistemology’. Galen’s autobiography traces a trajectory of moral improvement which cuts against the ‘ambitious’ programmes of Stoics and Epicureans, and instead models a graduated programme that moves from supervised ethical correction to one of self-scrutiny and introspection as the highest goal, as the experience of the most challenging and nuanced moral challenges may not be transparent to the outside observer.