Though these plans had been carried on in secret, yet Galileo's suspicions were excited; and he obtained leave from Cosmo to go to Rome about the end of 1615.[22] Here he was lodged in the palace of the grand duke's ambassador, and kept up a constant correspondence with the family of his patron at Florence; but, in the midst of this external splendour, he was summoned before the inquisition to answer for the heretical doctrines which he had published. He was charged with maintaining the motion of the earth, and the stability of the sun, with teaching this doctrine to his pupils, with corresponding on the subject with several German mathematicians, and with having published it, and attempted to reconcile it to Scripture, in his letters to Mark Velser in 1612. The inquisition assembled to consider these charges on the 25th of February, 1615; and it was decreed that Galileo should be enjoined by cardinal Bellarmine to renounce the obnoxious doctrines, and to pledge himself that he would neither teach, defend, nor publish them in future. In the event of his refusing to acquiesce in this sentence, it was decreed that he should be thrown into prison. Galileo did not hesitate to yield to this injunction. On the day following, the 26th of February, he appeared before cardinal Bellarmine, to renounce his heretical opinions; and, having declared that he abandoned the doctrine of the earth's motion, and would neither defend nor teach it, in his conversation or in his writings, he was dismissed the court. Having thus disposed of Galileo, the inquisition conceived the design of condemning the whole system of Copernicus as heretical. Galileo, with more hardihood than prudence, remained at Rome for the purpose of giving his assistance in frustrating this plan; but there is reason to think that he injured by his presence the very cause which he meant to support. The inquisition had determined to put down the new opinions; and they now inserted among the prohibited books Galileo's letters to Castelli and the grand duchess, Kepler's epitome of the Copernican theory, and Copernicus's own work on the revolutions of the heavenly bodies. Notwithstanding these proceedings, Galileo had an audience of the pope, Paul V., in March, 1616. He was received very graciously, and spent nearly an hour with his holiness. When they were about to part, the pope assured Galileo, that the congregation were not disposed to receive upon light grounds any calumnies which might be propagated by his enemies, and that, as long as he occupied the papal chair, he might consider himself as safe. These assurances were no doubt founded on the belief that Galileo would adhere to his pledges; but so bold and inconsiderate was he in the expression of his opinions, that even in Rome he was continually engaged in controversial discussions. The following very interesting account of these disputes is given by Querenghi, in a letter to the cardinal D'Este:--