Christianity may have been the dominant religion of the empire. However, it was not until the Edict of Thessalonica in 380AD that it became the only authorized religion in the Roman Empire. Until then pre-Christian faiths were still legal- and so a threat to Christianity- especially as many Christians regarded classical learning as pathways back to the pagan past. Study of ancient philosophy and culture had already led one Christian raised Emperor, Julian, back to the old ways. This learning, preserved in the minds of pagan teachers and their books was regarded as a threat.
So, pre Christian learning was demonized and many innocent philosophies and ideas became associated with magic. As this became apparent people began to burn “their entire libraries” to try to avoid impeachment. If they did not, after they were found guilty, the books would burn anyway. Ammianus Marcellinus described how “innumerable writings” belonging to the ‘guilty’. …were hauled out of various houses” and “burned in heaps as being unlawful…although the greater number were treatises on the liberal arts and on jurisprudence.”
As for those who studied and taught classical culture, they became a significant target for accusations of magic. Many were found guilty and executed. However, some were not. One of those who had not one but several lucky escapes was Libanius, a Greek teacher of rhetoric and noted intellectual and lifelong ‘pagan.’ Libanius had taught pagans and Christians alike, including Basil of Caesarea and John Chrysostom. Despite his paganism, he had also been well respected by the Emperor Constantius II. However, he had also been close friends with Emperor Julian. His friendship with the apostate emperor and his intellectual standing made him a target.
Libanius tells in his Autobiography how he almost fell victim to the hysteria of the trials. A jealous rival Bemarchius who Libanius had bested in public oratory accused him of using magic. He claimed Libanius knew an astrologer who “controlled the stars and through them could bring help or harm to men.” To support his accusations, Bermarchius rallied support from various “schoolmasters and professors” who were also jealous. Libanius was imprisoned. However, he managed to avoid the death when the governor “let it be known that…he intended to support the law and myself. Libanius was released and quickly accepted a post in Nicomedeia to avoid further repercussions.
However, not all those who were accused of magic in late antiquity were ‘pagans.’