Andrew William Clay, PhD Classics, University of Colorado (Boulder)
'Constantine, the Sibyl, and Instinctu Divinitatis'
The enigmatic phrase instinctu divinitatis on the Arch of Constantine in Rome has caused considerable trouble for historians interested in finding evidence for Constantine's early religious orientation. Due to the inscription's ambiguity of language, many scholars have situated the phrase automatically within the framework of Lactantius and Eusebius' narratives. In this way, the phrase is often interpreted as a veiled reference to Constantine's conversion experience before the Battle of the Milvian Bridge. This paper proposes to draw this automatic assumption into question. An examination of the arch itself reveals clues, both in the inscription and sculptures, indicating that the phrase instinctu divinitatis refers not to a single conversion experience immediately preceding the final battle between Constantine and Maxentius' forces, but to the entire campaign. From here, the study proceeds to shed light on the meaning of the phrase by examining three texts in which the theme of divine inspiration figures prominently: the panegyric of 310 (Pan. Lat. 6), 313 (Pan. Lat. 12), and Constantine's Oration to the Saints. The panegyrics support the view that the theme of divine inspiration predates Constantine's traditional conversion. More importantly, however, they provide evidence, in verbal and thematic parallels with his Oration to the Saints, of a link between instinctu divinitatis and Sibylline prophecy. This paper suggests that instinctu divinitatis refers to some pivotal moment shortly before or during Constantine's campaign into Italy, when the emperor received confirmation of divine support through a Christian forgery of a Sibylline oracle.