Luther was consecrated as a priest in 1507, and in 1508 he was invited by Frederic, Elector of Saxony, to become a professor in the new university which he had established at Wittemberg. He was now twenty-five years of age, and the fact, that he should have been selected, at that early age, to teach dialectics, is a strong argument in favor of his attainments and genius. He now began to apply himself to the study of the Greek and Hebrew, and delivered lectures on biblical theology; and his novel method, and great enthusiasm, attracted a crowd of students. But his sermons were more striking even than his lectures, and he was invited, by the council of Wittemberg, to be the preacher for the city. His eloquence, his learning, and his zeal, now attracted considerable attention, and the elector himself visited Wittemberg to hear him preach. In 1512, he was sent on an embassy to Rome, and, while in Italy, obtained useful knowledge of the actual state of the hierarchy, and of morals and religion. Julius II., a warlike pontiff, sat on the throne of St. Peter; and the "Eternal City" was the scene of folly, dissipation, and clerical extortion. Luther returned to Germany completely disgusted with every thing he had seen--the levity and frivolity of the clergy, and the ignorance and vices of the people. He was too earnest in his religious views and feelings to take much interest in the works of art, or the pleasures, which occupied the attention of the Italians; and the impression of the general iniquity and corruption of Rome never passed away, and probably gave a new direction to his thoughts. [Sidenote: Luther's Early Religious Struggles.] On his return, in 1512, he was made doctor of divinity, then a great distinction, and renewed his lectures in the university with great ardor. He gave a new impulse to the studies, and a new form to the opinions of both professors and students. Lupinus and Carlstadt, his colleagues, were converts to his views. All within his sphere were controlled by his commanding genius, and extraordinary force of character. He commenced war upon the schoolmen, and was peculiarly hostile to Thomas Aquinas, whom he accused of Pelagianism. He also attacked Aristotle, the great idol of the schools, and overwhelmed scholasticism with sarcasm and mockery.