On the Utility and Necessity of Prohibiting Harmful Books

St. Alphonsus Liguori

To protect the faithful from pernicious ideas, Pope Paul IV established the Index of Prohibited Books, which remained in use as a safeguard for the protection of public morals from 1559 A.D. until the reorganization of the Holy Office under Bl. Pope Paul VI in 1966 A.D. The Index came under attack during the time of St. Alphonsus Liguori, and he chose to include a treatise defending it in an Appendix to the first book of his great Theologia Moralis. St. Alphonsus was named a Doctor of the Church by Bl. Pope Pius IX in 1871 A.D. 

Alphonsus’s magisterial moral manual, which was praised by Pope Benedict XIV as being “of great profit for the salvation of souls”, has never yet been translated into English. Here we are pleased to present a translation of one chapter of Alphonsus’s Treatise on the Just Prohibition and Destruction of Dangerous Books, for the first time in English. The original text can be found here. —The Editors


The occasion of this treatise.
I have come across two hand-written letters recently, in which that very wholesome and entirely indispensible practice of the Church concerning the prohibition of books is wickedly assailed. The authors rashly maintain that, the law of the Church notwithstanding, any person may read any book whatsoever, so long as that book does not obviously appear to contain dangerous or subversive material.

The authors rely on two false arguments. First, that the practice of prohibiting books has been introduced into the Church only in recent times and is not founded in ancient practice. Second, that in ordering this practice the Church fails to observe due process of canon law, and therefore that a law of this sort bears no force of obligation.

I confess that I was quite amazed to see these novel opinions bruited with such impudence by the letters’ authors, since it is well enough established, first of all, that the practice of forbidding the reading of erroneous books has been promoted vigorously in the Church from the very earliest centuries, and upheld without interruption since then; and that the Catholic Church, in Her proscription of books, has always proceeded with careful discernment and due process.

My intention here is to treat this question copiously, principally because experience clearly shows how the aforementioned erroneous opinions considerably erode the authority of the Church and withdraw the minds of the faithful from that deference which is owed to the Church’s definitions. As a result, the poor faithful fall easily into many other errors contrary to faith and morals, resulting in an immense loss of souls.

For these reasons, I thought it worthwhile to publish this treatise, in which I will first show the necessity of prohibiting all books that can lead readers into error. Second, I will prove that the Church’s law forbidding books was established from its very origin and confirmed by uninterrupted custom. Thirdly, we will demonstrate how prudently and lawfully the church has always proceeded and even now proceeds in this prohibition. Finally, we will refute the frivolous objections of a number of heretics, from whom Catholics have incautiously borrowed opinions and shamelessly spread them among the public, causing great ruin among the faithful.




That we must avoid the society of heretics.
1. The Lord explicitly commands us to avoid heretical men with all effort and zeal, as much in the Old Testament[1] as in the New.[2] Most notably, we find in St. John (II Jn. 10): “If there come any unto you, and bring not this doctrine, receive him not into your house, neither bid him God speed.” For as St. Paul wisely said (II Tim. 2:16-17), their words “will increase unto more ungodliness. And their word will spread like a cancer.”

Hence John made every effort to avoid Ebion. He even scorned to enter a bathhouse if Cerinthus had used it.[3] Polycarp comported himself in the same way towards Marcion.[4] Eusebius of Vercelli preferred to die of hunger than to take bread from the hands of Arians.[5] St. Cyprian, speaking about certain excommunicates, warned his flock in this way: “Do not easily give ear to deceptive words, lest you mistake shadows for light…, poison for medicine, death for health… Keep yourselves far from these men’s contagion, and avoid their conversations as if you were fleeing a cancer or the plague.”[6]

Further, the Church always made sure that the faithful avoided any association with heretics and excommunicates, a fact to which St. Ephrem,[7] Alexander Alexandrinus,[8] St. Athanasius,[9] and St. Leo[10] testify together with the councils, Popes, and all the Fathers.

That dangerous books are much more to be avoided.
2. Therefore, if the Church so insistently commanded the faithful to avoid the company of anyone who speaks falsely, how much more ought Christians to avoid harmful books, which corrupt readers much more easily than speech? If the spoken word that instantly flits away still creeps in like a cancer and deals a mortal wound, what evil might not come from a dangerous book, which remains a perpetual font of subversion? An impious book can make its way into any home, even if the author himself is denied entry.

If religion and public order cannot be maintained while wicked men are allowed to spread false doctrines or circulate dangerous opinions contrary to accepted norms of morality—as the Congruit law says[11]—how much more will they be threatened if worthless rascals such as these are permitted to disseminate these same opinions even more widely in writing, and make them more compelling with cunning arguments that are more dangerous when read than heard? For whatever we read makes a stronger impression on our minds and more easily slips into our hearts. Just as holy reading can foster virtue, perverse reading urges us into vice; and more strongly so, since men are more naturally inclined to vice than to virtue. St. Basil was right to call books the food of the soul; because just as food is pleasurable while we eat it, and goes on to become human blood, so a book pleases when read—for who reads unwillingly?—and thus is more quickly digested.

Further, a reader gives himself like a student to the author he reads, offering him a docile and benevolent heart, and thus leaves himself vulnerable to deception. For it is very difficult not have some affection toward an author, from which it easily comes about that the impiety and error latent in the text is absorbed insensibly, and later tenaciously retained.

How impious writers disguise their poison.
3. Consider also that impious writers embellish their errors with great care, in order to deceive both the simple and the educated. They never state their case openly, at least in the beginning. Instead, they vest it in specious arguments, impressive erudition, and an attractive style, thus slipping a lethal venom past our guard.

While they earnestly profess their sanctity and zeal, protest their solicitude for the public good, and offer sound rules of perfection, they lurk like a snake in the grass. You will see them making innumerable references to Scripture and the Fathers, all of it either distorted or falsely interpreted. Thus the heretics have learned to deceive many, knowing that their fetid concoctions will not easily please if taken alone; and so with heavenly eloquence they dilute them with pleasing perfumes, so that some people who otherwise abhor impiety are led to hold divine revelations in contempt. About these the Savior cried: “Beware of false prophets, which come to you in sheep’s clothing, but inwardly they are ravening wolves”(Matt. 7:15). What does “sheep’s clothing” signify, if not that pretended piety with which deceptive authors skillfully endue themselves? what “ravening wolves” except the notions of heretics, who tear apart the Christ’s flock? “See,” Origin writes, “that the brilliance of the work does not deceive you, lest the beauty of its golden diction seize and carry you off.”[12] St. Gregory says the same: “The heretic mixes together truth with perversity in his speech, so that, by exhibiting good things, he captures the goodwill of his audience; and by giving out the bad, he corrupts them with hidden errors.”[13]

4. It is very pertinent here to refer to the words of a learned heretic, Abraham Le Moine, who, speaking about the many books published in English smacking of atheism, said this:

Books likes these, when many of them fall into the hands of the people, engender infinite harm, the more so because they appear at first so very well presented, with laudable intention and convincing argument. Each one defeats all incredulity. But these English authors, under the pretext of handing down the Gospel’s truth, supplant its very foundations with their subtle “difficulties” and subvert its principles, omitting nothing by which its teachings might be rendered deeply suspect. They foment a disease that much more lethal, as it is more subtle and casually admitted. Hence, persons of unsound mind drink deeply, seeing nothing to cause suspicion. They mix ironic taunts with erudite sayings, the better to obscure the truth with their filth. And because novelty causes delight, and religious instruction in this country is deplorable whilst the inclination to depravity is great, it is no wonder if books of this sort pervert the spirits and hearts of those who read them carelessly. The efforts of the agnostics bear quick fruit: readers are ensnared, scruples enter in, and finally they become unbelievers almost without knowing it. Thus an unrestrained liberty of thought necessarily and irresistibly creates license in the heart; these things indulge the passions and enlarge the dominion of the vices. Hence it may truly be said, that this great polity [he speaks of London] was never more depraved than it is today. And indeed nearly every other European state and kingdom is so miserably infected; but without a doubt they would be even worse off, if in them was permitted that liberty of thought, expression, and publication which exists here.

Thus far Le Moine. Certainly this heretic’s loud complaints alone suffice to show how indispensible it is for the support of religion and public peace to prohibit pernicious books.

And would what this author asserts in the last place were false, namely that the plague of atheism has infected many Catholics! To what ought this fact be attributed, except to the reading of books condemned for their false doctrines? Other Englishmen join this heretic in decrying this pestilence spreading among their nation; but meanwhile they take little care to suppress that excessive liberty of publication and access to books. In the times when England obeyed the Roman Church, there was not so much lament over agnostics, atheists, deists, or latitudinarians, for the very reason that none of them were allowed to publish, and none of the books promoting their doctrines were allowed to be read.

That men are corrupted by reading impious books.
5. Now we ought to demonstrate this through examples. Bl. Dionysius Alexandrinus, in Baronius,[14] attests that the harmful books of Nepos, a bishop on the side of the chiliasts, won over nearly half the Orient. In Mesopotamia, Bardesanes Syrus had already converted to the faith and was for a long time so conspicuous for his piety and so dutiful in opposing heretics in speech and writing that all Catholics admired him. But upon reading some volumes of the Valentinians, he not only subscribed to their errors but invented even more strange and atrocious errors, and thereby seduced innumerable men.[15] — St. Jerome asserts that Spain and Portugal would not have been contaminated, if the books of the Priscillians had not been published there.[16] — Similarly St. Turibius, in his letters to Idacius, Ceponius and Bl. Leo, deplores the corruption of Spain and Gaul of Narbonne on account of some wicked books, which he blamed as the sole cause of such a disaster.[17] — Eutyches, before an unconquerable defender of the faith, after one reading of a book of some Manichean, was changed into the unspeakable fount of innumerable heretics.[18] Afterwards, detained in a monastery, he was forced to keep his voice quiet, but notwithstanding the silence of their author his writings never ceased to conquer the East with their corruption. — Julian of Halicarnassus, in Caria, similarly defected from the faith after reading Valentinus’s books.[19] Avitus also, a Spanish priest, reading Origen’s books, although he read a confutation of them at the same time and had been admonished by Jerome to avoid his errors, mortally quaffed the disease.[20]

The mournful Heinrich Bullinger, a Catholic doctor, once not only very pious, but zealous for perfection, soon before he would have entered a Carthusian monastery happened upon a book of Melanchthon, and even though he was warned by a terrifying inner voice, compelled to read by a demon he read and he fell: and so, from the holy service of God the poor priest went to Satan.[21]

John Wycliffe, after many of his evil works were published in England, never made many followers for his errors as long as he taught them by word of mouth, even though he spoke almost nothing but calumny; but when he poured out his wicked books upon the public, he caused all Bohemia, which he had never even visited, to be lost, and handed the poisoned cup to even more. For when Jan Hus received Wycliffe’s books from a Bohemian who had studied at Oxford, he disseminated their impious doctrines everywhere.[22]

For the sake of brevity we have omitted other similar stories, which are found everywhere in history. It is plain enough to the educated that in nearly every case new heresies are drawn and copied from the books of other, older heretics.

That the Fathers protected the faithful from erroneous books.
6. Hence councils, Pontiffs, and saintly princes, by both pen and voice, by both censure and other penalties, were all for the extirpation of books that in any way worked to pollute faith and morals. — Hence the Fathers in their writings especially tried to steer the faithful from reading books of this sort. Origen maintained that those who peruse immodest or impious books without cause are guilty of the same sin as those who eat meat sacrificed to false gods.[23] St. Isidore wrote that reading impious works is the same as burning incense to the devil; and he added that it is not licit for Christians to read the lies of the poets, because they can excite the mind to lust. St. Jerome says: “No one steps into a leaky boat if he wants to learn to avoid shipwreck; would you then turn your innocent soul to a book full of heresies in order to learn the Catholic truth?” More strongly Tertullian: “No one is built up by that which destroys him; no one is illuminated by that which casts him into shadow.”[24]

Even heretics have done the same.
Even the blasphemous Luther published a book supporting the destruction of books containing false doctrines.[25] Calvin too would rail against bad books.[26] It is also known that in 1533, the books of Michael Servetus, together with their impious author, were all burned in Geneva by Calvin’s orders.

As have the Gentiles.
Even the gentiles, led by reason and experience alone, came to the same conclusion concerning the destruction of bad writings. Plato, for example, thought it necessary that books be subjected to examination by the wise before being passed on to others.[27]

The custom of burning books among the pagan nations.
7. Indeed, the custom of removing books of ill-repute prevailed in all the civilized nations of the world. Among the Hebrews, when he had received a book transmitted by Jeremiah through Baruch, Joachim cast it into the flames fearing it might be a scandal to the Jews.[28] King Herod, as well, wanted to burn all books of Hebraic origin, as dangerous to public peace.[29] — Among the Syrians, Antiochus Epiphanes decreed by public edict that the books of the Hebrews must be burned.[30] — Among the Athenians, Protagoras was abolished everywhere by legislative decree and his works consigned to public burning, since in them he cast doubt on the existence of the Gods. Cicero[31] and Lactantius. — [32] Among the Greeks, the works of Epicurus were also burned.[33]

Among the Romans, a farmer plowing his fields found an ancient tomb containing some works of Numa, in which Numa spoke unfavorably (though truly) about Roman religion. The Senate ordered them burned.[34] Marcus Aemilius, discovering a cargo of books being shipped to Rome, ordered that all of them be burned, since they contained novel rituals and prayers. In Baronius,[35] Arnobius asserts that the Romans tried to extirpate Cicero’s De Natura Deorum, where Cicero clearly seemed to speak against their religion.[36] Many Roman laws are extant commanding books of ill-repute to be burned.[37] Livy testifies that one duty of the Pontifex Maximus was to censure, condemn, and burn books.[38] Emperor Augustus burned over two thousand books whose authors were either unknown or disreputable.[39] The same emperor tried to prevent Ovid’s De Arte Amandi being read and sent its author into exile.

That obscene books and tracts about love must be removed.
8. Here we must insist that bishops and priests make every effort to remove from their sheep all books that are obscene or that treat of illicit love, books that Origen wisely called the cups of Babylon, full of venom, and St. Augustine: “Frogs climbing out of the mouths of beasts.” — Even the gentiles denounce this kind of indecent writing. Plato said that immodest books ought to be kept entirely out of cities. Among the Lacedaemonians and the whole Spartan realm, it was forbidden to read and own the books of Archilochus, because they were obscene.[40] There is a rumor passed on by Beyerlinck that Virgil ordered the Aeneid burned because of Dido’s immoral love affair.

On the emergence of “romance” literature.
Many books of this genre called “romance” (romanzi in the vernacular) are in common circulation everywhere today, and fall into the hands of simple adolescents. The creator of this Romance genre was Heliodorus, Phoenix, a bishop of Trikala in Thessalia, as Nicephorus has it.[41] This bishop had written such a book in his youth, which easily induced youths to immorality. A provincial synod, apprised of this danger, ordered Heliodorus to either burn his work or renounce his episcopate. He preferred to relinquish his office than to destroy his work.

That romances are dangerous and to be condemned.
9. The romance genre is not condemned universally by church law, for the Index bans only “books, which treat, narrate, or teach lascivious or obscene matters as their chief subject.”[42] Nevertheless, as a learned author Continuator Tournely notes, such books are often to be avoided per se, on account of the grave damage they cause to readers, for they are more dangerous when their intent is more disguised.[43] — Alexander Tassoni writes about this genre:

By reading about amorous chance incidents and schemes and obscene books, particularly in the solitude and leisure that literature requires, obscene phantasms and thoughts and desires for illicit things arise under the guise of pleasure and delight and the prudent faculties are abandoned.[44]

Further, these impurities do not gush forth upon him openly, but cloud his heart mysteriously by enkindling profane passions, alienating him from God and urging him strongly towards evil; just as, when the occasion is given, a man easily rushes into sinful lusts, and more intractably perseveres in them afterward.

This should be noted too, that sometimes fathers of families are guilty, because their duty is to keep these indecent books from the hands of their children. If they fail to do so, they must understand that they are guilty of sin. And let them not complain if their children neglect their studies because, obsessed with romances, they refuse to read more edifying books. Thus they remain uncultivated and turn out vicious. — John Gerson, writing against some romance book called On the Rose, mentions Augustus’s ban on Ovid’s book, exclaiming: “O God!…O the morals of our time! A pagan judge condemned another pagan whose teachings seduced men to immorality; and among Christians and by the agency of Christians this book and far worse are not only sold, but even praised and defended!”

10. Of a similar vein is the book entitled Faithful Shepherd (today explicitly condemned, for good reason); Peter Bayle says that there used to be an ignorant man who took it upon himself to defend this pernicious little book, arguing foolishly that it would cause no harm, if only girls would refuse the lovers who come to them! Bayle—though he is otherwise impious and irreligious—rightly berated that idiotic apologist (I translate from the French):

This response is sophistical because it demands a condition that the book itself makes very difficult. You ask two things: that we read the book, and that we refuse lovers. If you ask both these things, you are unjust, because the same poem undermines our strength to resist them. It fills us with sexual passions, ignites concupiscence, clouds the mind, impels us violently to seek the presence of lovers… But even granting we are able to refuse them: on account of these stories won’t we poor wretches still be tossed and turned by impure passions?

Bayle continues to insist that this genre of books ought to be everywhere entirely abolished.

That we must avoid the pagan poets.
11. Cicero wrote: “Do you see how much evil the poets bring? …they soften our hearts…, they destroy every fiber of virtue.[45] Thus Quintilian forbade the works of Horace and poets of his ilk to be read to his boys.[46] St. Jerome said: “The songs of poets are the food of demons.”[47] Even Luther, himself a man of the lowest morals, wrote: “The books of Juvenal, Martial, Catullus, and the Priapeia of Virgil must be removed from all cities and schools because they write such vile and obscene things that they cannot be read by the young without great harm coming of it.[48] — Even more dangerous is that wicked book of Boccaccio (which after being expurgated remains in circulation). In my opinion, it can do more damage to youths than the works of Luther and Calvin.

That the excuse of teaching language is a pretense.
Some argue that from these works students may learn not only choice idiom but also many things that are conducive to good morals. John Gerson responds well in his critique of the romance On the Rose: “I ask you, are the objectionable parts in them deleted? Fire is more dangerous. The baited hook still hurts the fish, and a honeyed blade cuts none the worse.” Gretserus sagely adds: “For these purposes you will find everything you need, but more pure, whole, and sincere in the writings of Catholic writers. What need is there to turn to those muddy little streams? Who would not more eagerly drink limpid water, than water tinctured with venom, even if he knows how to filter out the venom? At least the one who drinks water free of any contagion is spared the danger of death and the labor of filtration.”[49] — Augustine also wrote against those who would read Terence to learn vocabulary: “You will not learn those words more easily through their uncleanness; rather the uncleanness they teach will become easier to perpetrate. I do not blame the words…, but the draught of error to be found in them.”[50]

Wicked books must be rooted out and destroyed completely.
12. But let us return to our theme and draw the conclusions following from all the arguments adduced: Nature herself teaches that books offending religion or good morals should be destroyed by all possible means. All theologians teach the same, adding that not even the Pope Himself could permit someone to read a book that could be damaging to his faith. Juenin,[51] Continuator Tournely,[52] Graveson,[53] Busenbaum (see Lib. II, n. 19, ad 6), Habert.[54] The most learned Silvius adds, according to Continuator Tournely, that no one can read the works of heretics without proximate danger of grave sin, unless he has studied theology for at least three or four years.

Therefore if the gentiles, as we saw above, thought it necessary for the preservation of their false religion to destroy subversive books, how much harder must the Church strive to guard the true religion unscathed? “It is imperative,” said Theodosius, “that no one should so much as hear about any book provoking God’s wrath or tempting men’s souls to wickedness and deceit.” And Marcianus said: “The occasion of error is removed, if neither teacher nor listener are to be found.” And “May all the vestiges of wickedness perish utterly in flames.”[55] Charles V wisely offered these words: “If we throw away even the most expensive food when we suspect it of being tainted with poison harmful to the human body, how much more ought we to avoid those writers which are everywhere infected with such noxious venom for souls, and, so that no harm comes to others, should we not obliterate them from the memory of mankind?”[56]


[1] Deuter. XIII, 6 et seqq.

[2] Rom. XVI, 17; Tit. III, 10.

[3] Baronius, Annal., ad ann. 74, n. 8 et 9.

[4] Euseb., Histor. Eccles., lib. 4, cap. 14.

[5] Baronius, Annal., ad ann. 365, n. 96.

[6] Epist. 40, ad plebem, etc., n. 4 et 5.

[7] De Virtute, cap. 8.

[8] Epist. Ad Alexand. Constantinop., 13.

[9] Vita S. Anton., n. 68

[10] Serm. 16, de Ieiun., cap. 5.

[11] Edit.–The law Congruit referred to here contains this article: “The good and serious ruler must assure that the region he governs remains quiet and peaceful. This will not be difficult, if he takes care to find and rid the province of bad men, namely, the sacrilegious, robbers, kidnappers, and thieves.”

[12] Origen., in libr. Iesu Nave, homil. 7, n. 7.

[13] Moral., lib. 5, cap. 11, n. 28

[14] St. Dionysius Alexandrinus, in Baronius’s Annales Ecclesiastici, 264 A.D., n. 5, says that a false dogma (from a book of Nepos) was published: “so that not only were schisms born, but whole churches fell away from the faith.”

[15] Ephraim Chambers, Dizionar. Univers., v. Bardesanisti.

[16] St. Jerome, in Isaiam, lib. 17, cap. 64, v. 4 et 5, says that many young girls in Spain and Portugal were deceived by reading the apochryphal books, “to seek the portents of Basilis, Balsamus, and Thesaurus, Barbelo and Leusibora, and other names.”

[17] Zaccaria does relate this in Storia polemica delle proibizioni de’ libri, lib. 2, diss. 1, cap. 4, n. 5; but the letter of St. Turibius of Asturia is written only to Idacius and Ceponius, and is found among the epistles of St. Leo. Nor does the substance refer to Gaul of Narbonne, but to Gallicia, as it seems we can gather from Leo’s epistle 14.

[18] See Anastasius Sinaita

[19] Viae dux advers. Acephalos, cap. 14.

[20] Baronius, ad ann. 414, n. 10 et 11.

[21] Ladvocat, Dizionar. Portat, v. Bullinger.

[22] Cochleus, Historia Hussitarum, lib. 1, pag. 7 et seqq.; see also Bon. Blanciotti, Nota c ad doctrinam 6 Wicleffitarum, apud Thomam Waldensem, tom. 1, fol. 19.

[23] In Numer., homil. 20, num. 3.

[24] De Praescript., capit. 12.

[25] See Sleidanus.

[26] Braschius, De Libert. Eccl., tom. 3, capit. 26, num. 5.

[27] Plato, de Republ., dialog. 2, v. f.

[28] See Bodinus.

[29] Eusebius

[30] Joseph Hebraeus

[31] De Natur. Deor., lib. 1, cap. 23.

[32] Lib. De Ira Dei, cap. 9.

[33] Erasmus

[34] Valerius Maximus and Pliny

[35] Annal, ad ann. 302, n. 19.

[36] Advers. Gent., lib. 3, cap. 7; cfr. Migne, Patrol. Lat., tom. 5.

[37] L. Caeterae 4, ff. Familiae erciscundae, § Tantumdem; Paul. Jul. Sententiar. Receptar., lib. 5, tit. 23, § 12; L. Damnato 6 et 1. Quicumque 8, § ult., C. De haeret. et Manich.

[38] Lib. 6, cap. 1; cfr. IX, 46, et lib. 39, 16 (edit. Taurin.).

[39] Suetonius, In Octav. August., cap. 31. Origen, in Jerem., homil. 21, n. 7 et seq. Plato, de Repub., dialog. 2 et 10.; and Nicephorus

[40] Valerius Maximus

[41] Eccles. Hist., lib. 12, cap. 34.

[42] Reg. VII; cfr. et Constit. Officiorum, cap. 14, n. 9.

[43] De Decal., cap. 1, art. 1, punct. 3, § 2, concl. 2.

[44] Pensieri diversi, lib. 7, cap. 11, v. Che similmente.

[45] Tuscul. Disputat., lib. 2, cap. 11.

[46] De Institut. Orator., lib. 1, cap. 8, n. 6.

[47] Epist. 21, ad Damas., n. 13.

[48] Serm. Convivial., tit. de Authoribus; Gersonius, tract. Contra Romanti. De Rosa, v. Si dicatis.

[49] De Iure et more prohib. etc. libros haeret. etc., lib. 1, cap. 29.

[50] Confess., lib. 1, cap. 16, n. 26

[51] Instit. Theol., part. 7, diss. 4, qu. 1, cap. 6, art. 3, § 2, qu. 2.

[52] Decal., cap. 1, art. 1, punct. 3, § 2, concl. 2.

[53] Histor. eccl., saec. XVI, colloq. 6, i. f.

[54] Tr. De Fide, etc., cap. 4, qu. 9.

[55] Act. Concil. Halcedon., part. 3, cap. 12 et cap. 19. Cfr. 1. Quicumque 8, C. de Haeret. et Manich.

[56] Edict. Wormat. 1521, apud Petram, inconstit. Gelasii Valde, sect. un., n. 8.