Notwithstanding the personal prestige and the substantial advantages which were thus enjoyed by the book-dealers of the university, there were from time to time instances of protest, amounting occasionally to insubordination, on the part of the _libraires_, who, as their business aims and possibilities developed, became restive under the long series of trammels and restrictions, and particularly in connection with those imposed by the ecclesiastical division of the university authorities. The dread, however, of losing any portion of their privileges, and particularly the risk of any impairment of their monopoly of the book-trade of the university and of Paris, operated always as a sufficient consideration to prevent the insubordination from going to extremes. Throughout the entire period of the Middle Ages the control of the university continued, therefore, practically absolute over the book-trade of Paris, the influence of the Church and the (more or less spasmodic) authority of the Crown being exercised by means of the university machinery. This state of affairs continued for some period of years after the introduction of printing. The university still insisted upon its responsibility for the correctness and the completeness of the texts issued from the Paris press, although it gave up of necessity the routine of examining individual copies of the printed editions. On the other hand, the censorship control on the part of the theological Faculty over the moral character and orthodoxy of the works printed was insisted upon more strenuously than ever as the Church began to recognise the enormous importance of the influence upon public opinion of the widely distributed printed volumes. The effect of this ecclesiastical control upon the business of printing books is set forth with some detail in the chapter on the early printers of Paris. It is sufficient to say here that the contention on the part of the university to control, as a portion of the work of higher education, the business of the makers and sellers of books, while sharply attacked and materially undermined after the middle of the seventeenth century, was not formally abandoned until the beginning of the eighteenth. At this time the Crown took over to itself all authority to regulate the press, an authority which disappeared only with the revolution of 1789.