The introduction by the theological faculty states that the Emperor has charged the faculty with the duty of examining all the libraries and bookshops, and of taking out from these the books classed as heretical, together with those which bordered upon heresy, and also all writings which might prove dangerous for the unlearned. A separate class was to be made of the books which, while not condemned as heretical, were not to be left available for the use of the general public or of young people. The writers of the introduction admit that their lists might be more comprehensive. They point out, however, that the compilers had undertaken to condemn only those books which they had themselves had an opportunity of examining. They add a remark, which might to advantage have received further consideration on the part of the producers of later Indexes, to the effect that it was wiser to ignore books of a certain character rather than, in calling attention to them, to incite curiosity and risk bringing them into influence. The writers point out that the devout reader is in a position to judge, through the titles presented, as to the class of literature that he is instructed to avoid. The list of titles is arranged alphabetically, but the arrangement confuses together the surnames and the forenames of the authors and the titles of the books. A list is given of authors all of whose writings are prohibited. In certain instances, as with the names of Bucer, Bullinger, and Brenz, certain titles are specified and are followed by a general word to the effect that “as these authors are now known as notorious heretics, all of their writings are prohibited.” This first Index of the series makes a precedent, which was followed but very seldom in the later Indexes, in adding a list of works the use of which was commended and which were permitted for the schools. _5._ _1550._ _Louvain._ Index, prohibitory and permissive. Compiled, under the instructions of the emperor and by authority of the Senate of the Inquisition, by the University of Louvain. Title-pages and text in Flemish. _1550._ _Louvain._ The same, with Latin text. S. Sassenus. _Catalogi Librorum reprobatorum et praelegendorum ex judicio Academiae Lovaniensis. Cum Edicto Caesareae Majestatis evulgati Jussu, Gratia et Privilegio Caesaris Majestatis. Lovanii ex officina Servatii Sasseni._ _Les Catalogues des livres reprouvés, Et de ceux que l’on pourra enseigner aux enfans es escholles particulières selon le jugement de l’université de Louvain. Avec l’édict et mandement de la Maiesté Impériale._ The list of books condemned is closed with the words: _solam fidem sufficere ad salutem_. The condemned Bibles and New Testaments, in editions printed in various languages, aggregate forty-eight titles.