Index Librorum Prohibitorum

Index Librorum Prohibitorum, or Index Expurgatorius, an official list issued by the Roman Catholic Church, containing the names of all works the reading of which is forbidden on the ground that they tend to promote infidelity, heresy, or immorality. The edict of Constantine the Great, suppressing the writings of Arius, after they had been condemned in the Council of Niceea (A.D. 325), was the first of a series of imperial and Papal decrees which sought to uphold the authority of the Church in this matter. The first catalogue of prohibited works is said to date from the pontificate of Gelasius (494). The suppression of pernicious literature was generally entrusted to the bishops, but it afterwards became one of the functions of the Inquisition. The decree De Impressione Librqrum, issued by the Lateran Council in 1515, enacted that before being printed a work must receive ecclesiastical sanction. The first Roman index, in the modern sense of the word, was published by Pope Paul IV. in 1557. Owing to the vast increase in the number of unlicensed works, many of them containing direct attacks on the Papacy, which resulted from the Reformation, it was found necesseiry at the Council of Trent to entrust the preparation of a complete catalogue to a specially-appointed committee (1562). As its labours were unfinished when the council came to a close, the work was carried on by Pope Pius IV., who in 1564 issued an index which forms the basis of that now in force. It was accompanied by the "Ten Rules," explaining the principles on which it was drawn up and intended to serve as a guide for the revision and extension of the list. This task is now carried out by the "Congregation of the Index," comprising a prefect and other cardinals, together with "consulters" and "examiners of bboks." Besides books absolutely prohibited, there are others which may be read after the objectionable passages have been expunged. The Congregation has shown itself quite unable to keep pace with the growth of modern literature, and some of the most formidable attacks on the Roman system are omitted in the catalogue.