Papal influence, meanwhile, had been brought to bear on the Elector Frederick, to induce him not to take the part of Luther, and the chief agent chosen for working on the Elector and the Emperor Maximilian was the Papal legate, Cardinal Thomas Vio of Gäeta, called Caietan, who had made his appearance in Germany. The University of Wittenberg, on the other hand, interposed on behalf of their member, whose theology was popular there, and whose biblical lectures attracted crowds of enthusiastic hearers. He had just been joined at Wittenberg by his fellow-professor Philip Melancthon, then only twenty-one years old, but already in the first rank of Greek scholars, and the bond of friendship was now formed which lasted through their lives. The university claimed that Luther should at least be tried in Germany. Luther expressed the same wish through Spalatin to his sovereign. He now also answered publicly the attack of Prierias upon his theses, and declared not only that a Council alone could represent the Church, but that even a decree of Council might err, and that an Act of the Church was no final evidence of the truth of a doctrine. Being threatened with excommunication, he preached a sermon on the subject, and showed how a Christian, even if under the ban of the Church, or excluded from _outward_ communion with her, could still remain in true _inward_ communion with Christ and His believers, and might then see in his excommunication the noblest merit of his own. The Pope, meanwhile, had passed from his previous state of haughty complacency to one of violent haste. Already, on August 23, thus long before the sixty days had expired, he demanded the Elector to deliver up this 'child of the devil,' who boasted of his protection, to the legate, to bring away with him. This is clearly shown by two private briefs from the Pope, of August 23 and 25, the one addressed to the legate, the other to the head of all the Augustinian convents in Saxony, as distinguished from the Vicar of those congregations, Staupitz, who already was looked on with suspicion at Borne. These briefs instructed both men to hasten the arrest of the heretic; his adherents were to be secured with him, and every place where he was tolerated laid under the interdict. So unheard of seemed this conduct of the Pope, that Protestant historians would not believe in the genuineness of the briefs; but we shall soon see how Caietan himself refers to the one in his possession. Other and general relations, interests, and movements of the ecclesiastical and political life of the German nation now began to exercise an influence, direct or indirect, upon the history of Luther and the development of the struggles of the Reformation, and even caused the Pope himself to moderate his conduct.