In medieval imagery the aureola or halo was customarily used as a special emblem surrounding the head of a saint, a virgin or a senior ecclesiastic. By the late thirteenth century, this last category was considerably broadened, following the emergence and spread of universities as a new and dynamic infrastructure for higher learning. University teachers of theology asserted the right to have the honour of the halo extended to them in some cases. Several of them wrote about the convention, using it as an opportunity to talk about the role and status of their relatively new ‘profession’, as well as the ethical issues associated with it. As the author of this fine study remarks, ‘Over time, the debate on the doctoral halo evolved into a sort of safe space, serving as a textual arena where theologians could express their perspectives … within the bounds of an institutionally accepted form’ (p. 65).

These themes are developed in the meat of Esu’s book, in roughly chronological sequence. Chapter iii discusses the relative novelty of the aureola doctorum for university theologians of the thirteenth century, culminating in a survey of the views of Thomas Aquinas. As so often, the case made by the Dominican theologian represents a landmark in the process, extending the accepted capacity of preachers to be considered for the aureola to doctors of theology: that is, men who had received the highest academic qualification from a studium generale. Chapter iv examines some central issues raised by Aquinas which needed resolving to create a robust doctrine. Did a desire for vainglory disqualify a candidate from attaining the halo? And what about those who were unable to achieve the doctorate, maybe only because they could not afford the fees for the costly ceremony? These were issues for a number of writers who were clearly influenced by Aquinas, foremost among them his contemporary Henry of Ghent (d. 1293), Augustine of Ancona osa (‘Augustinus Triumphus’, d. 1328) and Robert Holcot op (d. 1349), who between them filled out many of Thomas’s arguments.

Chapter v picks up in the mid-fourteenth century and follows through to the late fifteenth, focusing on Peter of Palude/Pierre de la Palud op (d. 1342), Johannes Nider op (d. 1438), Franciscus Pelbartus of Temesvár/Timişoara ofm (d. 1504) and Nicholas of Dinkelsbühl (d. 1433). Their contributions included an emphasis on the need for public teaching in order to be eligible for the halo, as well as explanations of why it was reserved for teachers of theology (and, at a stretch, for the same theologians teaching philosophy when this was intended as explanation of theological points).

Chapter vi, on the fifteenth and sixteenth centuries, sees writers widening the debate yet further: with Jean Gerson (d. 1429) and Johannes Trithemius osb (d. 1516) expanding the criteria of eligibility to include those teaching through the production of written texts (and, in the case of Trithemius, by extension even copyists), who also contributed invaluably to the dissemination of the truth; Gottschalk Hollen osa (d. 1481) expressing scepticism about the excesses of degree ceremonies; the humanist Nicholas of Clamanges (d. 1430s) calling for a return to greater focus on the cure of souls; Wendelin Stambach (d. 1519) attacking academic malpractice; and the more obscure Vincenzo Barattieri of Piacenza op, who taught at Bologna between 1498 and 1503 and whose contributions to this subject come unusually in the form of a collection of orations at degree ceremonies, drawing explicit parallels between the celestial aureola doctoralis and the terrestrial birretta or academic cap awarded at the doctoral graduation. The final substantial chapter takes the case of John Mair (aka John Major), the Scottish philosopher (d. 1550) who wrote the most exhaustive treatment of the aureola – to all extents and purposes a treatise within a treatise – which considers virtually all the themes explored by his predecessors and many more besides. This is meticulously edited and translated in the appendix.

This book was published while Esu was still a doctoral candidate, working on a different topic. The range of his publications to date suggests that we can look forward to much more from this promising scholar. Finally, Brill are to be congratulated on launching their series of Mini-Monographs with this volume. This now neglected format is perfect for substantial scholarly contributions which do not quite meet the expected length of a full book but exceed the scope of a journal article. Given the likelihood that traditional academic career patterns will be further upended by AI, with all that it promises and threatens to do to research, cognition and the very shape of knowledge, a revival of the ‘middle way’ of the monograph may well prove to be an important strategy of dissemination for the future.