This published version of a PhD dissertation submitted in 2013 at the University of Basel offers a new look at the religion of the emperor Julian the Apostate as it can be gauged less from generic manifestations of his brief reign (ad 361–3) such as official documents, inscriptions or comments made by contemporaries, than, more importantly, from his own personal writings. The importance of this aspect of Julian's attitude to religion has recently been highlighted by research such as that undertaken by Nicholas Baker-Brian and Shaun Tougher, which resulted in the volume Emperor and author: the writings of Julian the Apostate (Swansea 2012). This kind of approach is still not very common, and there is a reluctance, especially among ancient historians, to engage with Julian's own literary outputs and interpret them critically in their own right rather than merely see everything that Julian wrote as generic expressions of just another late Roman emperor tied up in a Macchiavellian power game. In fact, Julian's writings seem to suggest that he was a rather complex character. Because of this, and the brevity of his reign, it may never be possible to understand fully what exactly was behind his rejection of Christianity and what exactly was the religion with which he wanted to replace it. The book under review tries to shed some new light on that latter question and it does so by taking very seriously Julian's own ‘theology’, as it becomes manifest in his own writings. It may be worth taking a close look at the title of the book in order fully to understand the innovative nature of what is on offer here: what is under scrutiny here is not Julian's worship of the gods, but of God. The implication of this slight difference is that Julian is here not studied as an emperor who tried simply to turn back the political and cultural clock and to reintroduce long redundant traditional cults, but as a ruler who also happened to be a philosophical thinker, and as such formulated his own theology, that is his own thinking, independent from any Church or other authority, about the one divine reality encountered by every human individual and by every nation as well as by humanity as a whole. This is not to say that Julian did not worship ‘the gods’, or even particular gods, but the underlying philosophy with which he rationalised this attitude is shown here not to be so fundamentally different from that of any other contemporaries, friends or opponents.

The book is divided into seven chapters. Chapters i, vi and vii cover introduction, conclusion and bibliography. The remaining five chapters study the main aspects of the divine-human relationship which Stöcklin-Kaldewey identified in Julian's theology: divine graciousness (‘Zuwendung’) – human dependence (ch. ii); divine revelation – human knowledge (ch. iii); divine offer of salvation – human hope (ch. iv), and divine claim [on humanity] – human responsibility (ch. v). It is easy to detect in this division the traditional subdivision of religion into ritual (liturgy), philosophy (or theoretical, doctrinal, theology), and ethics (i. e. the way in which theology manifests itself as law, or a code of conduct). All of these aspects can be found in Julian's religious writings. With regard to all of them Julian showed competence. All of them he took seriously in his own, original, way.

Of course, Stöcklin-Kaldewey concludes, Julian was in many ways a child of his age, late antiquity. His thinking on religion was influenced by the very same features as that of most of his contemporaries, be it Hellenism, a civic temple cult, Neoplatonism or Christianity. What makes him different from his contemporaries is the individualistic idiosyncrasy which he afforded himself to propagate his ideas. It is his individuality that made him so popular in the modern discourse. He did so, of course, from a privileged position, as an emperor. But, as for example a comparison with his immediate predecessor, Constantius ii, whose uncle he was, may show, individuality was not something we can take for granted, especially in a late Roman emperor. Julian was in many respects an exceptional emperor. Yet at the same time, as other recent research has also shown (see, for example, G. J. Zachhuber and A. Torrance [eds], Individuality in late antiquity, Farnham–Burlington, Vt 2014), there was indeed a more general development towards individuality in late antiquity. Thus it may well be worthwhile, as Stöcklin-Kaldewey indicates in her conclusion, to study other late antique intellectual projects that outline the changing relationship between individual and institution and to explore, for example, the role of authority (of ‘Scripture’, ‘Fathers’, ‘Church’, ‘Tradition’) in a wider than merely orthodox Christian context. But this is just one of several possible avenues of further study which Stöcklin-Kaldewey suggests. Another one is, for example, a revision of the sun-cult, in view of which Stöcklin-Kaldewey credits Julian with more originality than had previous scholars.

All in all this book is a most welcome new contribution to the study of religion in late antiquity and can be recommended to students of the history of the Early Church as well as to patristic scholars and those interested in Julian the Apostate and his religion.