On the other hand, it is well to remember that the young Emperor did not take the side of the Pope nor commit himself to the Curial ideas of the absolute character of papal supremacy. He laid stress on the unity of the Catholic (mediæval) Church, on the continuity of its rites, and on the need of maintaining its authority; but the seat of that authority was for him a General Council. The declaration in no way conflicts with the changes in imperial policy which may be traced during the opening weeks of the Diet, nor with that future action which led to the Sack of Rome and to the Augsburg Interim (1548). It is possible that the young ruler had read and admired Luther’s earlier writings, and that he had counted on him as an aid in bringing the Church to a better condition. It is more than probable that he already believed that it was his duty to free the Church from the abuses which abounded;(187) but Luther’s fierce attack on the Pope disgusted him, and a reformation which came from the people threatened secular as well as ecclesiastical authority. He had made up his mind that Luther must be condemned, and told the German princes that he would not change one iota of his determination. But this did not prevent him making use of Luther to further his diplomatic dealings with the Pope and wring concessions from the Curia. For one thing, the Pope had been interfering with the Inquisition in Spain, trying to mitigate its severity; and Charles, like his maternal grandfather, Ferdinand of Aragon, believed that the Holy Office was a help in curbing the freedom-loving people of Spain, and had no wish to see his instrument of punishment made less effectual. For another, it was evident that Francis I. was about to invade Italy, and Charles wished the Pope to take his side. If the Pope gave way to him on both of these points, he was ready to carry out his wishes about Luther as far as that was possible.(188) § 3. In the City of Worms.