Church music and art were set aside, clerical matrimony was preached, and infant baptism was rejected. Perhaps most importantly, in Orlamünde Karlstadt denied the physical but affirmed the spiritual presence of Christ in the communion. From Spring 1524, Luther started to campaign against Karlstadt, denying his right to publish and preach without Luther's authorization. In June, Karlstadt resigned as archdeacon. In July, Luther published the Letter to the Saxon Princes, in which he argued that Thomas Müntzer and Karlstadt agreed, and were both dangerous sectarians with revolutionary tendencies. Karlstadt defended the observance of the Sabbath, the seventh day of the week, as a holy day to the Lord. Martin Luther differed from him as he believed that Christians were free to observe any day of the week, provided it was uniform. His defense of the Sabbath, and others among the Anabaptists, caused him to be censured as a Jew and a heretic. On 22 August 1524, Luther preached in Jena. Karlstadt hid in the crowd during Luther’s preaching, and wrote to Luther, asking to see him. This led to the well-known confrontation at the Black Bear Inn in a conversation recorded by a Martin Reinhardt and published within a month. There were a number of misunderstandings between the two men. For example, Luther said that he was convinced that Karlstadt had revolutionary tendencies, despite the fact that Karlstadt had all along rejected violence in the name of religion, and rejected Thomas Müntzer's invitation to join the League of the Elect. Karlstadt's answer was published in 1524 in Wittenberg, and is still extant. This showed that Karlstadt continued to reject the violence that led to the German Peasants' War. Another defamation was Luther's accusation that Karlstadt was not authorized to preach at the city church in Wittenberg during Luther’s stay at Wartburg. The conversation ended when Luther gave Karlstadt a guilder and told him to write against him. In September 1524 Karlstadt was exiled from Saxony by Frederick the Wise and George, Duke of Saxony. Luther also wrote against Karlstadt in his 1526 The Sacrament of the Body and Blood of Christ—Against the Fanatics. Peasant War When the Peasant War broke out, Karlstadt was threatened and wrote to Luther and asked for assistance. Luther took him in, and Karlstadt lived secretly in Luther's house for eight weeks. However, Karlstadt had to sign a pseudo retraction, titled "Apology by Dr. Andreas Karlstadt