INDEX OF PROHIBITED BOOKS. — The expression “prohibited books” designates those books whose reading is forbidden to the faithful by positive ecclesiastical law, general or particular, or by decree issued by the competent authority, ordinarily the Sacred Congregation of the Holy Office or the local Ordinaries.
However, the faithful must refrain from reading not only books proscribed by law or decree, but also any writing that exposes them to the danger of losing the faith or corrupting their morals. This is a moral obligation imposed by natural law, which admits no exemption or dispensation. The gravity of this obligation is proportionate to the danger to which the soul is exposed.
But since simple faithful are rarely able to discern the danger they incur, it is natural that the Church, with suitable warnings and prohibitions, should keep them away from harmful reading.
The Index of Prohibited Books (Index librorum prohibitorum) is the catalogue of books that the Holy See has forbidden as bad or dangerous to the integrity of faith and morals, and which the faithful, without special permission, cannot read or possess. The Church has always fulfilled its duty of vigilance over books, but until the invention of printing it did not feel the need to compile a catalogue of prohibited books, because dangerous writings were burned.
The Council of Nicaea (325) forbade the book Thalia by Arius; Pope Anastasius condemned the works of Origen, because more harmful to the ignorant than useful to the learned; St. Leo the Great reproved in Rome the writings of the Manicheans and ordered the Spanish bishops to rise up against the books of the Priscillianists. From the earliest centuries the question of pagan classics was debated (v.). The danger grew with the spread of printed books, and then the intervention of the Church became more frequent. At first it intervened with the obligation of prior censorship (v.) imprimatur (v.), preceded in this by civil authority, such as Henry VIII in England and Charles V in the Netherlands, and by the Sorbonne in France.
Nevertheless, numerous heretical books were published, and Paul III, to stem the danger, entrusted the proscription of books infected with heresy to the cardinal inquisitors general. Paul IV was the first to order them, in 1557, to compile an Index (or catalogue) of prohibited books, which was published in 1559. It included three lists: of authors, of book titles, and of anonymous works. Pius IV then, acceding to a petition of the Council of Trent, had the Index revised and updated, which he published with the constitution Dominici gregis of 24 March 1564. It consisted of two parts: the first contained ten rules, which then appeared in all subsequent editions up to 1929, by which the categories of books prohibited by natural law or general law were fixed; the second gave, in alphabetical order, the catalogue of books proscribed by special decree. But not even the periodic compilation of a catalogue of prohibited books was sufficient to stem the spread of an evil nourished by new heresies and favoured by the spread of printing. Therefore Pius V established, in 1571, the Sacred Congregation of the Index (v. SACRE).
The following editions of the Index of Prohibited Books have been published, besides the one by Paul IV already mentioned: 1590, 1593, 1596, 1632, 1665, 1681, 1704, 1711, 1716, 1744, 1758, 1786, 1787, 1819, 1835, 1841, 1877, 1881, 1887, 1900, 1901, 1907, 1911, 1917, 1922, 1924, 1929, 1930 (in Italian and French), 1938, 1940, 1948. To these must be added some unofficial editions: 1580 (Parma), 1610 (Lyons), 1766 (Venice), 1783 (Parma), 1852 (Monte), 1899 (Turin). Leo XIII, with the constitution Officiorum ac munerum of 25 January 1897, promulgated a veritable unified text of the laws on the subject, which was then incorporated into the Code of Canon Law (tit. XXIII of Book III).
Yet these norms are not sufficient guidance for the faithful, and in concrete cases they give rise to doubts and uncertainties, because they lack that determinacy (the conceptual fixity of jurists) which is one of the characteristics of law. Therefore the Church sometimes intervenes and forbids specific books with particular decrees, even though they would be prohibited ipso iure, inserting them from time to time in the Index of Prohibited Books. For this reason the Code of Canon Law obliges all the faithful, and in particular clerics, especially those of ecclesiastical dignity or eminent for learning, to denounce pernicious books to the local Ordinaries or to the Holy Office (can. 1397 § 1). It reminds the Ordinaries of their duty to watch, directly or through suitable priests, over the books printed or sold in their dioceses (can. 1397 § 4). Residential bishops, whether acting singly or gathered in council, have the right and duty to condemn bad books (can. 1395 § 1); but they must refer to the Holy See publications that require difficult examination or that, because of their importance and diffusion, can be effectively proscribed only by the supreme ecclesiastical authority (can. 1397 § 5).
Books condemned by the Holy See are forbidden everywhere to all the faithful (can. 1396 and 1401), even if they are clerics, except for cardinals, bishops and other Ordinaries mentioned in can. 1398 § 1.
The categories of books whose reading is forbidden by natural law or general law (can. 1399) are:
1) Editions of the original texts of Holy Scripture prepared by non-Catholics and every translation of them published by them; — 2) All books that propose heresy, schism, or in any way attempt to demolish the foundations of religion; — 3) Books in which good morals or religion are deliberately attacked; — 4) Books by all non-Catholics that deliberately treat religious subjects, unless it is certain that they contain nothing contrary to the Catholic faith; — 5) Books printed without the prescribed ecclesiastical censorship, when they are books of Holy Scripture or related notes and commentaries or its translations into the vernacular (can. 1391), books on theological subjects, books or pamphlets of piety etc., or that report new apparitions, revelations, visions, prophecies, miracles or introduce new devotions; — 6) Books that attack or ridicule any Catholic dogma, defend errors condemned by the Holy See, attack divine worship, attempt to undermine ecclesiastical discipline, or deliberately cast aspersions on the ecclesiastical hierarchy or the clerical or religious state, always excepting the task of ecclesiastical historians and serious ones; — 7) All books of any kind that teach or recommend superstition, magic, sorcery, divination, spiritism and the like; — 8) Books that teach as licit duelling, suicide or divorce, that treat of Masonic sects or similar secret societies representing them as useful or not dangerous to the Church and the State; — 9) Books that openly treat, recount or teach lascivious or obscene things. Books of medicine or works of moral theology that deal with such matters for a serious purpose do not fall under this prohibition; — 10) Liturgical books in which changes are introduced so that they do not agree with the authentic editions approved by the Holy See; — 11) Books that publish spurious indulgences or those proscribed or revoked by the Holy See; — 12) All images of Our Lord Jesus Christ, the Blessed Virgin, the angels and saints or other servants of God, printed in any way, that are contrary to the sense and prescriptions of the Church.
It may however be held that the proscription of books does not bind non-Catholics born in schism or heresy, at least as regards positive ecclesiastical law.
Local Ordinaries may prohibit the reading of bad books only to their own subjects (can. 1395). Canonists and moralists commonly teach that exempt religious are not bound to observe civil laws in this matter. But it seems more accurate to affirm the contrary, if one carefully observes the expressions used in cann. 1395–1405. It is true that can. 1395 § 1 speaks of subjects, and exempt religious are not subjects of the bishop, but it does so solely to warn that the prohibition of the local Ordinary does not extend beyond the boundaries of his territory, as is deduced from a comparison of can. 1395 § 1 with can. 1396. Moreover, it must be borne in mind that the proscription of books, with the motu proprio *Alloquentes* (25 March 1917), has been entrusted to the Holy Office. Now no religious is exempt from the jurisdiction of the local Ordinary in matters within the competence of the Holy Office. Can. 1386 § 1 then expressly subjects all religious to the jurisdiction of bishops in this matter. A confirmation of what has been asserted is found in can. 1395 § 3: the legislator felt the need to expressly attribute to regular Ordinaries a power regarding the prohibition of books for their own subjects, precisely because can. 1395 § 2 strictly forbids them from interfering in cases within the competence of the Holy Office. Finally, it is well to note the different expressions used in §§ 1 and 3 of can. 1395: *ius et officium* in the first, “power” in the third. Now if the jurisdiction of regular Ordinaries over their own subjects in this matter were exclusive, even in § 3 one should read *officium*.
A prohibited book may not be published, read, possessed or detained, sold or bought, translated, communicated to others, without special permission, under pain of mortal sin.
Publishers of books by apostates, heretics or schismatics that promote apostasy, heresy or schism incur the penalty of excommunication specially reserved to the Holy See, if the work is published. The same penalty applies to the faithful who defend or knowingly retain or read, without due permission, the aforesaid books and those condemned by apostolic letters, which must not be confused with decrees of condemnation issued by the Holy Office. Authors and publishers who print books of Holy Scripture, notes or commentaries thereon without the required license incur the penalty of excommunication not reserved (can. 2318).
A prohibited book may not be republished unless the necessary corrections have been made and permission has been obtained from the one who condemned it, from his successor or from the competent superior (can. 1398 § 2).
Besides the Supreme Pontiff, only the Holy Office can grant the license to read or retain prohibited books *ipso iure* or by decree issued by the Holy See. Local Ordinaries may grant such permission only to their own subjects, in urgent cases and for individual books (can. 1402 § 1). Local Ordinaries, however, have broad powers—limited only by natural law and any possible intervention by the Holy Office—over books prohibited by themselves or their predecessors; not even a general license granted by the Holy See authorizes the reading of books prohibited by Ordinaries, unless the apostolic indult expressly states that they may read or retain books condemned by whomever (can. 1403 § 1). Clearly, the permission obtained does not exempt any person from the prohibition, arising from natural law, of reading books that expose one to proximate spiritual danger. Permission is not usually granted to read books that deliberately treat obscene matters; and it is forbidden to keep them on deposit, sell them or lend them out. Local Ordinaries and parish priests must warn the faithful of the danger to which they expose themselves and of the harm they will suffer from reading immoral books.
The Holy Office, for its part, with an instruction issued on 3 May 1927 (*AAS*, 19 [1927], pp. 186–89), exhorted local Ordinaries to watch over all writings printed or published in their dioceses and to point out to the faithful the books prohibited *ipso iure*, whose reading is forbidden under pain of mortal sin, and reminded them of the provision of can. 1395 § 1: they have not only the right but also the duty to proscribe books deserving of condemnation. The Holy Office has had to return to the subject several times (the most recent intervention is that of 17 April 1947, in which the obligation laid down in can. 1397 is recalled).
Lately, moreover, to the flood of immoral books has been added Marxist publishing (books, magazines, newspapers), which attempts to undermine the foundations of the Christian religion. The Holy Office, therefore, with a decree issued on 28 June 1949, declared such writings prohibited *ipso iure* under can. 1399, and imposed the penalty of *latae sententiae* excommunication, specially reserved to the Holy See, on those who profess, defend or spread the materialist and anti-Christian doctrine of communism (*AAS*, 41 [1949], p. 334).
INDEX OF PROHIBITED BOOKS – INDIFFERENTISM
386: J. Brys, *De lectione pravorum diariorum*, in *Coll. Brugen.*, 28 (1928), pp. 125–29; S. Goyenèche, *Potestate superior localis prohibere librum aut periodicum suis subditis?*, in *Comm. pro religiosis*, 9 (1928), p. 427; M. Lecler, *Facoltà di leggere libri proibiti*, in *Perfice munus*, 3 (1928), pp. 865–66; S. Woywod, *Prohibition of books*, in *The homil. and past. rev.*, 28 (1928), pp. 1086–95; G. Buttignoni, *Sulla proibizione dei libri*, in *Palestra del clero*, 10 (1931), pp. 257–59; Matteo a Coronata, *Institutiones iuris canonici*, II, Turin 1931, nn. 959–66; S. Goyenèche, *An requiratur facultas S. C. Indicis ad retinendos libros prohibitos in armario clauso custodiendo*, in *Comm. pro religiosis*, 13 (1932), pp. 198–99; A. Gennaro, *Sulla proibizione dei libri*, in *Perfice munus*, 7 (1932), pp. 743–44; M. I. Browne, *Are non-catholic encyclopedies prohibited - ipso jure?*, in *The irish eccles. record*, 43 (1934), pp. 80–83; Wernz-Vidal, IV, nn. 717–34; A. Genicot–I. Salsmans, *Institutiones theologiae moralis*, Brussels 1942, nn. 451–460; H. Wagnon, *Le nouvel Index des livres prohibits*, in *Rév. dioc. de Tournai*, 3 (1948), pp. 3–23; L. Firpo, *Filosofia italiana e controriforma*, in *Rivista di filosofia*, 41 (1950), pp. 150 ff., 390 ff. Cf. also: A. Thourenin, *Index*, in *DTHC*, VII, cols. 1570–1580; J. Forget, *Index*, in *DFC*, II, cols. 702–16; G. Casati, *L’I. dei l. p. Saggi e commenti*, 3 voll., Milan 1937.
ARTURO DE LOIRO