In the Index of Benedict, while no specific statement to such effect is made, the compilers had evidently been instructed to concentrate their censorship labours upon books which, bearing the names of Catholic writers, and printed, for the most part, within Catholic territory, were likely to have influence with readers among the faithful. The authorities of the Church had finally recognised, after a series of experiments continuing during two centuries, that it was not practicable for a group of Italian priests, working in Rome, to keep themselves adequately informed concerning the productions of the printing-press throughout the civilised world. It was not only a physical impossibility to secure knowledge of the contents of these books, printed no longer in one universal language of literature and scholarship but in all the languages of civilisation; it was even impracticable to obtain and to utilise for Index purposes any fairly complete bibliographies of their titles. From the time of Benedict to the present day, the censorship of the Church has therefore restricted its efforts in the main to the supervision of Catholic literature. It is necessary, however, to use the term “in the main” because the Index of Benedict and the succeeding Indexes, including even the two promulgated by Leo XIII, include, in connection with the long lists of doctrinal works by Catholic writers, a curious sprinkling of books written by Protestants for Protestant communities, the majority of which books have no concern whatsoever with doctrinal matter. It it very difficult to arrive at any understanding of the policy on which these selections, comprising a few dozen volumes out of many thousands, have been arrived at. It does not seem to have been based on the relative importance, as hundreds of productions which secured a world-wide reputation, and the influence of which has been decidedly adverse to the contentions of the Church, have received no attention, while volumes of lesser significance have been found worthy of condemnation. The lists of the Catholic books have also, under the system pursued by the editors of Benedict and their successors, been largely reduced. The method pursued by the Benedictine compilers of condemning _in toto_ certain classes of literature and all books relating to certain specified subjects, saves the editors from the necessity of presenting long lists of titles. In no other manner, in fact, could the conclusions of the censors of the 18th and 19th centuries in regard to the current productions of the printing-press have been brought within reasonable compass. The Index of Benedict marks the beginning of the modern policy of the Church in the matter of censorship.