It was in 1529 that Calvin is said to have experienced a sudden "conversion." Although as yet there had been no organized revolt in France against the Catholic Church, that country, like many others, was teeming with religious critics. Thousands of Frenchmen were in sympathy with any attempt to improve the Church by education, by purer morals, or by better preaching. Lutheranism was winning a few converts, and various evangelical sects were appearing in divers places. The chief problem was whether reform should be sought within the traditional Church or by rebellion against it. Calvin believed that his conversion was a divine call to forsake Roman Catholicism and to become the apostle of a purer life. His heart, he said, was "so subdued and reduced to docility that in comparison with his zeal for true piety he regarded all other studies with indifference, though not entirely abandoning them. Though himself a beginner, many flocked to him to learn the pure doctrine, and he began to seek some hiding-place and means of withdrawal from people." [Sidenote: "The Institutes"] His search for a hiding-place was quickened by the announced determination of the French king, Francis I, to put an end to religious dissent among his subjects. Calvin abruptly left France and found an asylum in the Swiss town of Basel, where he became acquainted at first hand with the type of reformed religion which Zwingli had propagated and where he proceeded to write a full account of the Protestant position as contrasted with the Catholic. This exposition,--_The Institutes of the Christian Religion_,--which was published in 1536, was dedicated to King Francis I and was intended to influence him in favor of Protestantism. Although the book failed of its immediate purpose, it speedily won a deservedly great reputation. It was a statement of Calvin's views, borrowed in part from Zwingli, and in part from Luther and other reformers. It was orderly and concise, and it did for Protestant theology what the medieval writers had done for Catholic theology. It contained the germ of all that subsequently developed as Calvinism. [Sidenote: Calvin and Luther] It seemed for some time as if the _Institutes_ might provide a common religious rule and guide for all Christians who rebelled against Rome. But Calvin, in mind and nature, was quite different from Luther. The latter was impetuous, excitable, but very human; the former was ascetic, calm, and inhumanly logical. Then, too, Luther was quite willing to leave everything in the church which was not prohibited by Scripture; Calvin insisted that nothing should remain in the church which was not expressly authorized by Scripture. The _Institutes_ had a tremendous influence upon Protestantism but did not unite the followers of Calvin and Luther. Calvin's book seems all the more wonderful, when it is recalled that it was written when the author was but twenty-six years of age. [Sidenote: Calvin at Geneva]