P. 438. "Hence in particular must they grievously offend God who either directly put away from them the faith of the Church, or else accept it only in so far as it appears to them correct according to the selection [out of her tenets] which they have made; or, again, who so break the bond of the unity of the Church as to declare themselves loose from obedience to the lawful authority which in her has been set over them by God. Thus are we led to speak of the three ecclesiastical crimes—apostasy, heresy, and schism."
P. 440. "As to apostasy, which is the total rejection of the Christian faith, and the falling away into Judaism, or heathenism, or Islamism, it is here only to be remarked that in the view of the Church it is as the crime of insulting the majesty of God. The apostate must be compelled to return to the Church by force, and a milder judgment may be pronounced upon him only in the case of one who was compelled to deny his faith by the unbelievers."
P. 441. "In opposition to the entire rejection of the Christian faith, heresy implies the wilful selection of a number from out of the dogmas of the Church which are to be believed by men in all their fulness, and the restricting of faith to such selected doctrines as the man still adheres to; in general to this is added the acceptance of false articles of faith. In this wider sense, all those are called heretics who accept only particular doctrines of the Church; but we must distinguish between such. We must part off error from heresy. Any man may fall into error, with regard to one or another doctrine of the Church, against his own will, out of simplicity, or from want of instruction, or because he has received wrong instruction. Such an error of the understanding is called 'material heresy'; but proper heresy, which is called 'formal heresy,' has its seat in the will. The latter consists in this, that to error is added obstinacy of the will, which is disinclined to depart from it. If any one announces a doctrine and then learns that the Church teaches otherwise, thus discovering that he was in error, he does not fall into heresy if he only ceases to defend the doctrine which he has set forth, and submits himself to the teaching of the Church. On the other hand, one who does know that the Church teaches otherwise, and still affirms that something is an article of belief which is not so, or, contrariwise, that something is not an article of belief which is so, doing this in spite of the fact that the Church has delivered the truth upon the subject, he by so doing haughtily prefers his own judgment to that of the Church; and through this obstinacy, the characteristic mark of heresy, he becomes a heretic in the strict sense of the word.
"It is not necessary to heresy that the person shall, as a heresiarch, found a new sect, or that, by free choice, he shall go over to a sect condemned by the Church; but heresy is already present whenever any one in the bosom of the Catholic Church departs from only one single point of the faith, or understands one single passage of Holy Scripture otherwise than as the Church, with the assistance of the Holy Ghost, expounds them. For so great is the importance of heresy that through want of faith even on one point, the proper foundation of faith itself is destroyed, so that he that makes himself guilty with regard to one dogma, becomes at the same time guilty as to every dogma of the Church. Thus not only is he who rejects one of the articles defined by the Church a heretic, but also he who after such a definition maintains that the point is still doubtful."
P. 445. "The Church prays for the return of her separated members, and she is entitled to proceed to compulsion by virtue of the jurisdiction over heretics as baptized persons which belongs to her; but she uses, by prayer and by the instruction which is permitted to all, the only means by which she can now enter into communication with them, at least as relations at present stand.
"She may, indeed, tolerate the heathen, because they err through ignorance; she may tolerate the Jews as witnesses for the truth; but she cannot tolerate heresy, because this shakes the foundation of the entire faith. The synagogue makes way for the Church as a dutiful handmaid, bringing her the Holy Scriptures. Heresy, however, lifts itself up as a mistress above the Church, discredits her utterly, sets itself to judge over her, and would condemn her out of Holy Scripture according to its self-chosen exposition, closing her mouth like that of Christ. It commences with the divine Word, but it treats that word like a lyre, from which every one at pleasure, may draw whatever note will suit him.
"The Church pardons error, but she cannot subject herself to the obstinately erring will, but must destroy its dominion and its tyranny. She, as the teacher of the truth, cannot conclude a peace with such a will. She cannot lift it up to the throne beside her, she cannot share her dominion with it. Understood in its proper and true signification, heresy is a frightful crime. Do the heathen blaspheme God out of ignorance? Heresy tears truth to pieces consciously. Did the Jews crucify Christ according to the flesh? Heresy fastens the Church, His mystical body, to the cross. Therefore the Church cannot at all tolerate heresy, because the greatest danger of seduction is attached to it. The Christian can easily shun the heathen and the Jew, but not the Christian who by the baptismal vow is connected with him, but by heresy is separated from him.
"On these grounds is explained the complete intolerance which the Church, in all her laws, and especially in the Bulla Cæna, has manifested against heresy. Hence are explained the certainly hard-sounding expressions with which she speaks of heresy. Hence the punishments against heretics, the delivering up of the same to the temporal arm, and the calling upon temporal princes by law and by arms to come to her help in rooting out heresy. When the Church pronounces excommunication upon heretics, it is nothing more than a declaratory sentence of that which had already been announced by the heretics themselves; for, all the more because these are Christians, must she separate them from herself, that they may not be accounted as of her, and that she may not appear as chargeable for their obstinacy.
"Hence it will be understood that the Church employs all means to keep her members from being infected with heretical teaching. She has therefore, with the apostle, forbidden intercourse with heretics; yet she makes this apply, according to the Bull of Martin V, Ad evitandos, only to those who are personally, and by name, excommunicated on account of their obstinacy. To a like end the Church forbids to the faithful the reading of heretical writings, which still retain that character even when the author perhaps erred only out of ignorance, and has given his books to the fire. So according to the diversities of times and circumstances does she require from her members the assurance of fidelity in making the confession of faith, causing those who return into her bosom to abjure heresy, and prohibiting all to preach who have not thereto an express mission, and forbidding the laity to dispute as to the faith, except in cases in which especial exceptions are justified."
P. 451. "Schism, in its proper meaning, consists in this, that the baptized person, while not doubting as to the faith, and while not intending to separate himself from it, declares himself free from the authority which God has set over him in the Church. In a looser sense of the word, schism may refer to one's own bishop, as well as to the Pope; properly, however, it requires separation from the centre of Church unity, from the Pope, to constitute a schism, although revolt against the proper bishop, recognized by the head of the Church, comprehends in itself separation from the entire Church. And how will the schismatic, separated from ecclesiastical unity, preserve himself in purity of doctrine? Does heresy lead to schism? So infallibly does schism lead to heresy, inasmuch as only through false doctrine can it be justified. Therefore does the Church regard schism as a crime just as great as heresy, and in general has dealt with it in the same manner."