Luther mentions, as if it were an exceptional instance, that in 1506, when he was a student in Erfurt, he had bought a copy of the _Corpus Juris_ (the book from which the lecturer was then giving instruction).[125] It was evidently at this time not common for students to own copies of the text-books in use. Thomas Plater relates in his autobiography that in the school of S. Elizabeth at Breslau, as late as 1515, there was usually but one text-book for each class. The instructor or one of the students would read this for dictation, and the students having taken their notes would memorise them for recitation.[126] When Melanchthon began, in 1524, his lectures on Demosthenes, the only copy of the _Orations_ in town was that owned by the lecturer. The chief representative of the intellectuality of the Lutheran movement was doubtless Philip Melanchthon. Of Melanchthon’s relations with the literary and publishing activities of the time, the limits of this chapter will not permit any full consideration. It is sufficient to say that, apart from his service as a preacher, and as collaborator on the German Bible, he devoted himself particularly to the work of preparing text-books for higher grade students, a work which earned for him the title of _Præceptor Germaniæ_. He edited, and himself in part wrote a series of text-books for use in the high schools and universities on the subjects of Latin and Greek Grammar, Rhetoric, Theology, Ethics, Physics, and Physiology. These books displaced in the institutions of Protestant Germany the works of Catholic writers, many of which were survivals of the schoolmen, and were entirely antiquated and inadequate. The contention maintained by so many good Catholics, that no literature that had once been sanctioned by the Church as good and sufficient, could ever lose its value or authority, was of course especially abused when applied to works of instruction. Under the initiative chiefly of Melanchthon, Wittenberg became the centre of instruction for the preachers and teachers of all Lutheran Germany, while for a considerable period Strasburg filled a similar place for the Calvinists of the South-west. While the immediate direction of this educational work fell to Melanchthon, the inspiration for it, as for so much of the intellectual activity of the Reformation, is very largely to be credited to Luther, who had from an early stage in the Reform work insisted upon the necessity of defending the minds of the younger generation from the influence of the educational traditions and routine doctrinal teachings of the Church schools.