Converting after Constantine: Firmicus Maternus and the Scriptures

Abstract: The two extant works by the senator Julius Firmicus Maternus, a manual of astrology ( Mathesis , ca. 337) and a ferocious attack on senatorial paganism ( De errore profanarum religionum , 343–50), offer exceptional insight into the transformation of a convert's beliefs in the era of Constantine. Study of Firmicus's Christianity has long been hampered by distaste for his desire to see pagan cult annihilated and by the belief that he took essentially all of his scriptural knowledge from Cyprian's Ad Quirinum and Ad Fortunatum . Recent scholarship has dealt with the first issue. This article focuses on the second. Surveying Firmicus's biblical quotations and allusions, it demonstrates that he had extensive knowledge of biblical passages that Cyprian does not cite, ranging far beyond the Psalms (which Firmicus is generally thought to have known independently). He interprets Cyprianic texts in light of non-Cyprianic parallels, cites surrounding context, weaves in references to liturgical custom, and deploys well-known exegetical motifs such as the interpretation of Psalm 23 (LXX) in reference to Christ's descent and ascension. Combined with his heavy reliance on Cyprian for quotations, Firmicus's use of biblical passages and extrabiblical theological ideas suggests that he was widely read in scripture, but that had to hand only Cyprian's collections, with whose explanatory headings his ideas about coercion and his Christology engage. Firmicus's engagement with scripture, in part through Cyprian's mediation, thus illustrates the processes by which an upper-class convert could assimilate Christian ideas. His integration of astral language into his description of Christianity, in turn, undercuts modern generalizations about the Christianity of the Constantinian era. Far from being at home with pagan conceptions of the universe, Firmicus reworks them to exalt Christ and the cross above the stars themselves.