With regard to Christians, because they were taught not to avenge themselves upon their enemies, and have thus observed laws of a mild and philanthropic character; and because, although they were able, yet they would not have made war even if they had received authority to do so; for this cause they have obtained this from God: that He has always warred on their behalf, and at times has restrained those who rose up against them and who wished to destroy them. For in order to remind others, that seeing a few engaged in a struggle in behalf of religion, they might also be better fitted to despise death, a few, at various times, and these easily numbered, have endured death for the sake of the Christian religion; God not permitting the whole nation [_i.e._, the Christians] to be exterminated, but desiring that it should continue, and that the whole world should be filled with this salvation and the doctrines of religion. (_g_) Justinian, _Digest_, I, 5:17. The edict of Caracalla (Marcus Aurelius Antoninus) conferring Roman citizenship upon all free inhabitants of the Empire has not been preserved. It is known only from a brief extract from the twenty-second book of Ulpian’s work on the Prætorian Edict, contained in the _Digest_ of Justinian. Those who were in the Roman world were made Roman citizens by the constitution of the Emperor Antoninus. § 35. Religious Syncretism in the Third Century In the third century religious syncretism took two leading forms—the Mithraic worship, which spread rapidly throughout the Empire, and the fashionable interest in novel religions fostered by the imperial court. Mithraism was especially prevalent in the army, and at army posts have been found numerous remains of sanctuaries, inscriptions, etc. It was by far the purest of the religions that invaded the Roman Empire, and drew its leading ideas from Persian sources. The fashionable court interest in novel religions seems not to have amounted to much as a positive religious force, which Mithraism certainly was, though on account of it Christianity was protected and even patronized by the ladies of the imperial household. Among the works produced by this interest was the _Life of Apollonius of Tyana_, written by Philostratus at the command of the Empress Julia Domna. Apollonius was a preacher or teacher of ethics and the Neo-Pythagorean philosophy in the first century, _ob._ A. D. 97. Additional source material: Philostratus, _Life of Apollonius_ (the latest English translation, by F. C. Conybeare, with Greek text in the _Loeb Classical Library_, 1912). Mithraic Prayer, Albrecht Dietrich, _Eine Mithrasliturgie_, Leipsic, 1903.