The Canons of the Fourth Lateran Council, 1215 CANON 3
Text. We excommunicate and anathematize every heresy that raises against the holy, orthodox and Catholic faith which we have above explained; condemning all heretics under whatever names they may be known, for while they have different faces they are nevertheless bound to each other by their tails, since in all of them vanity is a common element. Those condemned, being handed over to the secular rulers of their bailiffs, let them be abandoned, to be punished with due justice, clerics being first degraded from their orders. As to the property of the condemned, if they are laymen, let it be confiscated; if clerics, let it be applied to the churches from which they received revenues. But those who are only suspected, due consideration being given to the nature of the suspicion and the character of the person, unless they prove their innocence by a proper defense, let them be anathematized and avoided by all 1-intil they have made suitable satisfaction; but if they have been under excommunication for one year, then let them be condemned as heretics. Secular authorities, whatever office they may hold, shall be admonished and induced and if necessary compelled by ecclesiastical censure, that as they wish to be esteemed and numbered among the faithful, so for the defense of the faith they ought publicly to take an oath that they will strive in good faith and to the best of their ability to exterminate in the territories subject to their jurisdiction all heretics pointed out by the Church; so that whenever anyone shall have assumed authority, whether spiritual or temporal, let him be bound to confirm this decree by oath. But if a temporal ruler, after having been requested and admonished by the Church, should neglect to cleanse his territory of this heretical foulness, let him be excommunicated by the metropolitan and the other bishops of the province. If he refuses to make satisfaction within a year, let the matter be made known to the supreme pontiff, that he may declare the ruler's vassals absolved from their allegiance and may offer the territory to be ruled lay Catholics, who on the extermination of the heretics may possess it without hindrance and preserve it in the purity of faith; the right, however, of the chief ruler is to be respected as long as he offers no obstacle in this matter and permits freedom of action. The same law is to be observed in regard to those who have no chief rulers (that is, are independent). Catholics who have girded themselves with the cross for the extermination of the heretics, shall enjoy the indulgences and privileges granted to those who go in defense of the Holy Land.

We decree that those who give credence to the teachings of the heretics, as well as those who receive, defend, and patronize them, are excommunicated; and we firmly declare that after any one of them has been branded with excommunication, if he has deliberately failed to make satisfaction within a year, let him incur ipso jure the stigma of infamy and let him not be admitted to public offices or deliberations, and let him not take part in the election of others to such offices or use his right to give testimony in a court of law. Let him also be intestable, that he may not have the free exercise of making a will, and let him be deprived of the right of inheritance. Let no one be urged to give an account to him in any matter, but let him be urged to give an account to others. If perchance he be a judge, let his decisions have no force, nor let any cause be brought to his attention. If he be an advocate, let his assistance by no means be sought. If a notary, let the instruments drawn up by him be considered worthless, for, the author being condemned, let them enjoy a similar fate. In all similar cases we command that the same be observed. If, however, he be a cleric, let him be deposed from every office and benefice, that the greater the fault the graver may be the punishment inflicted.

If any refuse to avoid such after they have been ostracized by the Church, let them be excommunicated till they have made suitable satisfaction. Clerics shall not give the sacraments of the Church to such pestilential people, nor shall they presume to give them Christian burial, or to receive their alms or offerings; otherwise they shall be deprived of their office, to which they may not be restored without a special indult of the Apostolic See. Similarly, all regulars, on whom also this punishment may be imposed, let their privileges be nullified in that diocese in which they have presumed to perpetrate such excesses.

But since some, under "the appearance of godliness, but denying the power thereof," as the Apostle says (II Tim. 3: 5), arrogate to themselves the authority to preach, as the same Apostle says: "How shall they preach unless they be sent?" (Rom. 10:15), all those prohibited or not sent, who, without the authority of the Apostolic See or of the Catholic bishop of the locality, shall presume to usurp the office of preaching either publicly or privately, shall be excommunicated and unless they amend, and the sooner the better, they shall be visited with a further suitable penalty. We add, moreover, that every archbishop or bishop should himself or through his archdeacon or some other suitable persons, twice or at least once a year make the rounds of his diocese in which report has it that heretics dwell, and there compel three or more men of good character or, if it should be deemed advisable, the entire neighborhood, to swear that if anyone know of the presence there of heretics or others holding secret assemblies, or differing from the common way of the faithful in faith and morals, they will make them known to the bishop. The latter shall then call together before him those accused, who, if they do not purge themselves of the matter of which they are accused, or if after the rejection of their error they lapse into their former wickedness, shall be canonically punished. But if any of them by damnable obstinacy should disapprove of the oath and should perchance be unwilling to swear, from this very fact let them be regarded as heretics.

We wish, therefore, and in virtue of obedience strictly command, that to carry out these instructions effectively the bishops exercise throughout their dioceses a scrupulous vigilance if they wish to escape canonical punishment. If from sufficient evidence it is apparent that a bishop is negligent or remiss in cleansing his diocese of the ferment of heretical wickedness, let him be deposed from the episcopal office and let another, who will and can confound heretical depravity, be substituted.