‘In his books against the Donatists, Augustine shows the effects of this contention. First of all great Christian teachers, he formally defended the persecution of heretics. The shedding of the blood of the Priscillianists had indeed been undertaken at the instigation of bishops, but other and better bishops had deplored it. Here, however, were heretics destroying churches and assaulting clergy. Their evil must be met with evil. Their violence must be resisted with violence. Augustine tried in vain to keep the precepts of the Sermon on the Mount. He was disposed to love his enemies. But he hated the Donatists. They seemed to him to be outside the limits of Christian forbearance. He advised treating them as thieves and robbers should be treated. In a writing entitled “De” Correctione Donatistanum,” he held that the civil power ought to restrain schism. He was the first to translate the hospitality of a parable into the hostility of a religious war, and to find a sanction for persecution in the words “Compel them to come in.” He might as well have taken for a text, “Rise, Peter, kill and eat!” The principle proceeded easily from the punishment of wrong acting to the punishment of wrong thinking. Augustine became an apostle of intolerance. Thus the controversy with the Donatists continued until all the clamorous voices were silenced, in the year when Augustine died, by the victorious invasion of the Vandals.’
George Hodges, The Early Church: From Ignatius to Augustine (pp. 153-154). Moellon House. Kindle Edition.