By the mid fourth century c.e., violently divergent Christian communities had developed across the Roman empire: Nicene or Homoousian (God and Jesus ‘are of the same substance’), Homoiousian (‘are of similar substance’), Homoian (Jesus is ‘like’ God), Anomoean or Heterousian (God and Jesus ‘are of different substance’) and others. The first emperor to be a strong supporter of traditional cult in more than a generation, Julian ruled over an empire of numerous religious groups that were often at variance with one another, both extra- and intra-communally, and how all of these should be treated was one of the chief problems pressing the emperor upon his accession in late 361. Julian's religious thought and action during his short sole reign (3 November 361 to 26 June 363) has long exercised scholars, its impact on Christians and Christianity in particular. To be sure, Julian tended to be hostile to Christians and Christianity, but he was by no means hostile to all, and he even favoured some Christians, some of whom he counted among his friends and officials. The emperor's Christian policy thus was complicated. One of the best examples of this complexity is Julian's epistle to the Heterousian Christian leader Aetius (Ep. 15 Wright = 46 Bidez). In a shorter note published in this journal, Pierre-Louis Malosse focussed his attention on Julian's letter to Aetius, which dates to early 362 and which is the only such epistle to this future bishop that is extant. As transmitted, Julian's missive to Aetius is critical for the light it helps to shed on the emperor's views and treatments of Christians at the outset of his sole reign, and my conclusions on this missive differ from those of Malosse.