Pope has retreated from the public gaze to spend a private day with his brother after criticising radical Islam in the last major address of his six-day visit to his native Bavaria. With the criticisms still resonating, the pontiff`s only scheduled public appearance Wednesday was to inaugurate a new organ in the ancient church of Our Lady of the Old Chapel in Regensburg. Benedict, looking sprightly for his 79 years, paused to greet a crowd of several thousand people outside the church, clasping their outstreched hands and blessing babies held out to him by their parents. As the former Professor Joseph Ratzinger, the pope lived in the southern city from 1969 to 1977 when he lectured in the local university, and he still maintains a house in the suburb of Pentling. In an address to bless the organ, he appealed for unity within the Catholic Church, where pressure groups have challenged traditional views of marriage and the family. "Just as in an organ an expert hand must constantly bring disharmony back to consonance, so we in the Church ... always need to find anew, through our communion in faith, harmony in the praise of God and in fraternal love." The pope was to have lunch with his brother Monsignor Georg Ratzinger, an 82-year-old retired priest, at his house in Regensburg. Local newspapers reported they were likely to eat the pope`s favourite Bavarian dish of braised beef, known as Tafelspitz. The brothers were then to visit the nearby Ziegetsdorf cemetery to pray at the graves of their mother, father and sister. They were then to spend what the Vatican described as "private time", including dinner at the pope`s house in Pentling. His address late Tuesday to academics at Regensburg University, in which he fleetingly criticised the Islamic concept of "Jihad" or holy war, hit the only political note of his visit, during which his addresses have been almost entirely spiritual. "Violence is incompatible with the nature of God and the nature of the soul," said the pope, during a complex treatise on reason and faith. Vatican spokesman Father Federico Lombardi said he did not believe the pope`s words, just a few paragraphs in a speech lasting more than 30 minutes, were meant as a severe criticism of Islam. "I believe that everyone understands even inside Islam there are many different positions, and there are positions that aren`t violent," Lombardi said. "He certainly doesn`t want to give a lesson... an interpretation of Islam as violent. He is saying that in the case of violent interpretation of religion, we are in contradiction with the nature of God and the nature of the soul." But some of those who heard the speech said the meaning was clear. Father Karlheinz Bumb, 60, a priest who as a theology student was taught by the future pope in Regensburg, said as he watched Benedict arrive at the chapel: "You can clearly deduce from his speech criticism of Islamic extremism and the holy war."