Though he had apparently renounced forever all thoughts of a clerical life, he retained, even while he was engaged in the study of law and in the more congenial pursuit of literature, his early love for theology; and in 1532, under the influence of some of Luther's writings which happened to fall into his hands, he was converted to the Protestant faith and threw in his fortunes with the little evangelical party in Paris. His intellectual attainments made him a marked man wherever he went, and he speedily became the leading spirit in the circle to which he had attached himself. Compelled soon afterward by the persecuting measures of King Francis I. to flee the country, he took up his residence at Basle and settled down, as he hoped, to a quiet literary life. It was during his stay here that he published in 1536 the first edition of his greatest work, 'The Christian Institutes,' in which is contained the system of theology which has for centuries borne his name, and by which he is best known to the world at large. Probably no other work written by so young a man has ever produced such a wide-spread, profound, and lasting influence. In its original form, it is true, the work was only a brief and simple introduction to the study of the Scriptures, much less imposing and forbidding than the elaborate body of divinity which is now known to theologians as 'Calvin's Institutes': but all the substance of the last edition is to be found in the first; the theology of the one is the theology of the other--the Calvin of 1559 is the Calvin of 1536. The fact that at the age of twenty-six Calvin could publish a system of theology at once so original and so profound--a system, moreover, which with all his activity of intellect and love of truth he never had occasion to modify in any essential particular--is one of the most striking phenomena in the history of the human mind; and yet it is but one of many illustrations of the man's marvelous clearness and comprehensiveness of vision, and of his force and decision of character. His life from beginning to end was the consistent unfolding of a single dominant principle--the unwavering pursuit of a single controlling purpose. From his earliest youth the sense of duty was all-supreme with him; he lived under a constant imperative--in awe of, and in reverent obedience to, the will of a sovereign God; and his theology is but the translation into language of that experience; its translation by one of the world's greatest masters of logical thought and of clear speech. Calvin's great work was accompanied by a dedicatory epistle addressed to King Francis I., which is by common consent one of the finest specimens of courteous and convincing apology in existence. A brief extract from it will be found in the selections given below.