Johann Eck, Luther's chief opponent, realising that there was no hope of stirring up the German authorities to take action, hastened to Rome to impress upon the Pope and his advisers the extreme gravity of the situation, and to urge them to proceed against the revolt with all possible energy and despatch. Luther himself recognised clearly enough that the crisis he had long foreseen was at hand, and he began to prepare men's minds for complete rupture with the Church by his sermon on excommunication in which he bade defiance to the ecclesiastical authorities. He threw himself with renewed energy into the fray, turning out volume after volume with feverish rapidity, each more violent and abusive than its predecessor, and nearly all couched in language that was as intelligible to the peasant as it was to the professor. In his /Address to the Nobles of Germany/, in his works /On the Mass/, /On the Improvement of Christian Morality/, and /On the Babylonian Captivity/, he proclaimed himself a political as well as a religious revolutionary. There was no longer any concealment or equivocation. The veil was lifted at last, and Luther stood forth to the world as the declared enemy of the Church and the Pope, the champion of the Bible as the sole rule of faith, and the defender of individual judgment as its only interpreter. In these works he rejected the Mass, Transubstantiation, vows of chastity, pilgrimages, fasts, the Sacraments, the powers of the priesthood, and the jurisdiction and supremacy of the Pope. With such a man there could be no longer any question of leniency or of compromise. The issues at stake, namely, whether the wild and impassioned assertions of a rebel monk should be accepted in preference to the teaching of Christ's Church, ought to have been apparent to every thinking man; and yet so blinded were some of his contemporaries by their sympathy with the Humanists as against the Theologians, that even still they forced themselves to believe Luther sought only for reform.