The Epistles of Cyprian

⁴ But if, among these insane persons, their incurable madness shall continue, and, with the withdrawal of the Holy Spirit, the blindness which has begun shall remain in its deep night, our counsel will be to separate individual brethren from their deceitfulness; and, lest any one should run into the toils of their error, to separate them from their contagion. Since neither can the oblation be consecrated where the Holy Spirit is not; nor can the Lord avail to any one by the prayers and supplications of one who himself has done despite to the Lord. But if Fortunatianus, either by the blindness induced by the devil forgetful of his crime, or become a minister and servant of the devil for deceiving the brotherhood, shall persevere in this his madness, do you, as far as in you lies, strive, and in this darkness of the rage of the devil, recall the minds of the brethren from error, that they may not easily consent to the madness of another; that they may not make themselves partakers in the crimes of abandoned men; but being sound, let them maintain the constant tenor of their salvation, and of the integrity preserved and guarded by them.