RC Encyclopedia quoted above -
However, the successors of Constantine were ever persuaded that the first concern of imperial authority (Theodosius II, "Novellae", tit. III, A.D. 438) was the protection of religion and so, with terrible regularity, issued many penal edicts against heretics. In the space of fifty seven years sixty-eight enactments were thus promulgated. All manner of heretics were affected by this legislation, and in various ways, by exile, confiscation of property, or death. A law of 407, aimed at the traitorous Donatists, asserts for the first time that these heretics ought to be put on the same plane as transgressors against the sacred majesty of the emperor, a concept to which was reserved in later times a very momentous role. The death penalty however, was only imposed for certain kinds of heresy; in their persecution of heretics the Christian emperors fell far short of the severity of Diocletian, who in 287 sentenced to the stake the leaders of the Manichaeans, and inflicted on their followers partly the death penalty by beheading, and partly forced labor in the government mines.
So far we have been dealing with the legislation of the Christianized State. In the attitude of the representatives of the Church towards this legislation some uncertainty is already noticeable. At the close of the forth century, and during the fifth, Manichaeism, Donatism, and Priscillianism were the heresies most in view. Expelled from Rome and Milan, the Manichaeism sought refuge in Africa. Though they were found guilty of abominable teachings and misdeeds (St. Augustine, De haeresibus", no. 46), the Church refused to invoke the civil power against them; indeed, the great Bishop of Hippo explicitly rejected the use force. He sought their return only through public and private acts of submission, and his efforts seem to have met with success. Indeed, we learn from him that the Donatists themselves were the first to appeal to the civil power for protection against the Church. However, they fared like Daniels accusers: the lions turned upon them. State intervention not answering to their wishes, and the violent excesses of the Circumcellions being condignly punished, the Donatists complained bitterly of administrative cruelty. St. Optatus of Mileve defended the civil authority (De Schismate Donntistarum, III, cc. 6-7) as follows:
. . . as though it were not permitted to come forward as avengers of God, and to pronounce sentence of death! . . . But, say you, the State cannot punish in the name of God. Yet was it not in the name of God that Moses and Phineas consigned to death the worshippers of the Golden calf and those who despised the true religion?
This was the first time that a Catholic bishop championed a decisive cooperation of the State in religious questions, and its right to inflict DEATH on heretics. For the first time, also, the Old Testament was appealed to, though such appeals had been previously rejected by Christian teachers.
