When Luther in his later years speaks of the “sins of his youth,” this, in his grotesquely anti-catholic vocabulary, means the good works of his monastic life, even the celebration of Holy Mass. Once, however, at the end of his tract on the Last Supper (1528),[63] speaking of the sins of his youth, he seems to distinguish between the Catholic works above referred to and other faults of which he accuses himself in the same general terms. In the young Augustinian’s Erfurt days he was prevented by the Rule from cultivating any intimate and distracting friendship with persons in the world. We only know that he, and likewise his brother monk Johann Lang, had some friendly intercourse with the Humanist Petreius (Peter Eberbach), who not long after, in a letter dated May 8, 1512, greets Lang—then already with Luther at Wittenberg—in these words: “_Sancte Lange et Sancte Martine orate pro me_.” Mutianus, the Gotha canon and chief of the Humanists, who was very unorthodox in his views, in a letter to Lang of the beginning of May, 1515, seems to remember Luther, for he sends greetings to the “pious Dr. Martin.” His intercourse with the Humanists led Luther to make use of philology in the interpretation of the Holy Scriptures. He thus entered upon a useful, we may even say indispensable, course, in which he might have done great service. At Erfurt he continued constantly to study his copy of the Bible, which had become an inseparable companion. “As no one in the monastery read the Bible” (at any rate not with his zeal) he was able to flatter himself with being first in the house in the matter of biblical knowledge; indeed in this field he was probably the greatest expert in the whole Congregation. In addition to this, he began to turn his busy mind to the study of Hebrew, and contrived to provide himself with a dictionary, which at that time was considered a treasure. Lang, with his humanistic culture, was able to assist him with the Greek. Meanwhile the dispute in the Order with regard to the observance had reached a point when it seemed right to the party to which Luther belonged to seek the intervention of Rome in their favour, or to anticipate an appeal on the part of their opponents. The choice of seven houses “of the observance” resulted in Luther being chosen as the delegate to represent them in Rome. So little opposed to the Church was Luther’s theology and Bible interpretation in his Erfurt days, and so considerable was the number of brethren, even in other Observantine houses who held him to be a faithful monk, that they deemed him best suited for so difficult a mission. What Cochlæus, according to information drawn from Augustinian sources, relates later sounds, however, quite reasonable, viz. that he was selected on account of his “cleverness and his forceful spirit of contradiction,” which promised a complete victory over the other faction.[64] Luther’s journey to Rome, according to Oldecop, was undertaken from Erfurt.