I have presented this summary of the published writings of Luther simply as an example of the literary undertakings and of the publishing methods of the time. What has been said about the printing and the distribution of the works of Luther could be repeated in regard to the long series of productions of most of the other writers of the Reformation, such as Melanchthon, Zwingli, Oecolampadius, and also those of their opponents, Cochläus, Eck, and the others. It was doubtless an obstacle in the way of the development of the conception of property in literary productions, that during the first century of the printing-press, so large a proportion of the publications which were the work of contemporary writers, belonged to the class of religious, doctrinal, and controversial literature. The chief purpose of authors like Luther and Zwingli, was, as we have seen, to secure the widest possible distribution for their teachings. They believed that a right understanding of certain doctrines was essential to salvation, and they believed, further, that the responsibility had been confided to them of bringing these doctrines to humanity. It was not easy for authors holding such a conviction to undertake to restrict or control the sale of their writings for the purpose of securing profits for themselves. There would, of course, under the existing conditions, have been many difficulties in the way of carrying out such control if it had been attempted. The fact remains, however, that such attempts were but infrequent. With this attitude on the part of the writers, and of those who were earnestly interested with these writers in establishing creeds and in influencing public opinion, it is not surprising that the practice became general of reprinting any material for which there was demand, or for which it was believed that a demand could be created.