William Ockham's interests were turned to political philosophy by the circumstances of his life. As early as 1323, he became entangled in the controversy of his order on evangelical poverty with the pope, John XXII, who by his bull, Ad conditorem canonum, issued on December 8, 1322, withdrew from the Franciscans the right of holding property in the name of the Holy See, granted to them by Innocent IV in 1245, and by Nicholas III in 1279. The case seems trifling, yet it involved the interpretation of the life of Christ himself, whom the sons of St. Francis tried to imitate by substituting the use of property for its ownership. The “Spirituals” stood for the original views of the order and considered the papal bull as dragging them down to worldliness and abasement. Ockham in a sermon delivered at Bologna attacked the pope's conception of apostolical poverty. John XXII, in a bull dated December 1, 1323, and addressed to the bishops of Ferrara and Bologna, ordered his arrest and held him in Avignon for four years for trial. In August, 1325, a commission of six theologians, one of whom was Durandus de St. Porciano, at that time bishop of Meaux, was appointed to investigate his theological and philosophical doctrines. In 1326 the commission declared fifty-one articles taken from his Commentary to the Sentences as heretical. On April 13, 1328, Ockham signed the protest of the general of the Franciscan order, Michael Cesena, also under arrest, against the papal bull of 1322, which condemned the tenet of evangelical poverty. The night of May 24, 1328, brought a dramatic turn in his life. He succeeded in escaping from the papal prison in the company of Cesena and Bonagratia of Bergamo, the famous civil and canon lawyer, and fled to Pisa to seek the protection of Louis of Bavaria, emperor of Germany and archenemy of the pope.