The Duke of Pomerania requested Luther to preach before him, on the occasion, in his chapel. Luther gladly complied. The chapel was soon filled, and crowds still arriving, it became necessary to remove to the great hall of the castle, where the discussion was held. Luther preached from the text of the day, on the grace of God, and the power of Peter, and gave a popular exposition of the views which he was wont to maintain before a learned audience. Christianity causes the light of truth to penetrate alike into the highest and the humblest intellects, and is in this way distinguished from all other religions, and from all philosophical systems. The theologians of Leipsic, who had been present at the sermon, hastened to acquaint Eck with the expressions which had offended them. "These subtile errors," exclaimed they, "must be answered, must be publicly refuted." This was just what Eck wished. All the churches were open to him, and on four successive occasions he mounted the pulpit to declaim against Luther and his sermon. Luther's friends were indignant, and demanded that the theologian of Wittemberg should be heard in his turn. But they demanded in vain. The pulpits were open to the enemies of evangelical truth, but shut against those who proclaimed it. "I kept silence," says Luther, "and was obliged to submit to attacks, insults, and calumnies, without being able to exculpate and defend myself."[92] [92] Mich verklagen, schelten und schmæhen.... (L. Op. (L.) xvii, p. 247.) [Sidenote: QUARRELS OF DOCTORS.] The ecclesiastics were not the only persons who displayed hostility to the evangelical doctrine: the citizens of Leipsic were in this respect of one mind with their clergy, and yielded themselves up with blind fanaticism to the falsehoods and animosities which were industriously propagated. The principal inhabitants did not visit either Luther or Carlstadt. They left them unnoticed when they met them in the street, and tried to prejudice the duke against them. On the other hand they visited and gave daily entertainments to the doctor of Ingolstadt, who enjoyed their good cheer, and learnedly discussed the comparative merits of Saxony and Bavarian beer. His manners, somewhat free, did not indicate a very strict morality.[93] The only thing offered to Luther was the customary present of wine to the disputants. Moreover, even those who wished him well were anxious that others should not know it; several Nicodemites visited him by night or in secret. There were only two who did themselves honour by publicly declaring their friendship. These were Dr. Auerback, whom we have already met at Augsburg, and Dr. Pistor, junior. [93] Eck to Haven and Bourkard, 1st July, 1519. (Walch, xv, p. 1456.)