"foolish madmen shall be branded with the ignominious name of heretics"
The Edict of Thessalonica, February 27, 380
Emperor Constantine the Great authorised Christianity across the Roman Empire in 313, but it was Theodosius I, half a century later, who put the brute force of the imperial state behind the faith. 1
The Emperor Constantine (306 to 337) ordered all copies of the Thalia, the book in which Arius had expressed his teachings, to be burned.
The Edict of Thessalonica (February 27, 380) ordered all subjects of the Roman Empire to profess the faith of the bishops of Rome and of Alexandria, making Nicene Christianity the state religion of the Roman Empire. Publications of Nicene sects were prayerfully considered and then burned.
The Edict declared:
We authorize the followers of this law to assume the title of Catholic Christians but as for the others, since, in our judgment they are foolish madmen, we decree that they shall be branded with the ignominious name of heretics, and shall not presume to give to their conventicles the name of churches. They will suffer in the first place the chastisement of the divine condemnation and in the second the punishment of our authority which in accordance with the will of Heaven we shall decide to inflict.2
Lyons, Mathew. 2021. “27 February 380 the Edict of Thessalonica.” History Today, no. 2 (February): 27 .
The Edict of Thessalonica was jointly issued by Theodosius I, Gratian, and Valentinian II on 27 February 380.
References:
Barry, William. "Arianism." The Catholic Encyclopedia. Vol. 1. New York: Robert Appleton Company, 1907.
Elliott, Thomas George. 1992. “Constantine and ‘the Arian Reaction after Nicaea.’” The Journal of Ecclesiastical History 43 (2): 169–94.
Ferguson, Everett. 1976. “Voices of Religious Liberty in the Early Church.” Restoration Quarterly 19 (1): 13–22.
Ryan, E A (Edward Anthony). 1944. “The Problem of Persecution in the Early Church.” Theological Studies 5 (3): 310–39.