ON HERESY

From the Third Canon of the Fourth Lateran Council, on heresy, (Innocent III, 1215):

Let secular authorities, whatever offices they may be discharging, be advised and urged and if necessary be compelled by ecclesiastical censure, if they wish to be reputed and held to be faithful, to take publicly an oath for the defense of the faith to the effect that they will seek, in so far as they can, to expel from the lands subject to their jurisdiction all heretics designated by the church in good faith. Thus whenever anyone is promoted to spiritual or temporal authority, he shall be obliged to confirm this article with an oath. If however a temporal lord, required and instructed by the church, neglects to cleanse his territory of this heretical filth, he shall be bound with the bond of excommunication by the metropolitan and other bishops of the province. If he refuses to give satisfaction within a year, this shall be reported to the supreme pontiff so that he may then declare his vassals absolved from their fealty to him and make the land available for occupation by [good] Catholics so that these may, after they have expelled the heretics, possess it unopposed and preserve it in the purity of the faith…

These are the words (emphases mine) of Christ's Vicar on Earth.

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