<P> The French Reformer John Calvin (1509--1564) was a theological writer who produced many sermons, biblical commentaries, letters, theological treatises, and other works . Although nearly all of Calvin's adult life was spent in Geneva (1536--38 and 1541--64), his publications spread his ideas of a properly reformed church to many parts of Europe and from there to the rest of the world . It is especially on account of his voluminous publications that he exerts such a lasting influence over Christianity and Western history . </P> <P> Calvin's first published work was an edition of the Roman philosopher Seneca's De Clementia, accompanied by a commentary demonstrating a thorough knowledge of antiquity . His first theological work, the Psychopannychia, attempted to refute the doctrine of soul sleep as promulgated by Christians whom Calvin called "Anabaptists ." He finished it in 1534 but, on the advice of friends, didn't publish it until 1542 . The work demonstrates that since his conversion, Calvin had undertaken serious study and now showed a mastery of the Bible, and he had become, using Karl Barth's words, a "theological Humanist" and a "biblicist"--that is, "no matter how true a teaching might be, he was not ready to lend an ear to it apart from the Word of God ." </P> <P> At the age of twenty - six, Calvin published the first edition of his Institutes of the Christian Religion (Latin title: Institutio Christianae Religionis), a seminal work in Christian theology that is still read by theological students today . It was published in Latin in 1536 and in his native French in 1541, with the definitive editions appearing in 1559 (Latin) and in 1560 (French). The book was written as an introductory textbook on the Protestant faith for those with some learning already and covered a broad range of theological topics from the doctrines of church and sacraments to justification by faith alone and Christian liberty, and it vigorously attacked the teachings of those Calvin considered unorthodox, particularly Roman Catholicism to which Calvin says he had been "strongly devoted" before his conversion to Protestantism . The overarching theme of the book--and Calvin's greatest theological legacy--is the idea of God's total sovereignty, particularly in salvation and election . </P> <P> Calvin also produced many volumes of commentary on most of the books of the Bible . For the Old Testament, he published commentaries for all books except the histories after Joshua (though he did publish his sermons on First Samuel) and the Wisdom literature other than the Book of Psalms . For the New Testament, he omitted only the brief second and third Epistles of John and the Book of Revelation . These commentaries, too, have proved to be of lasting value to students of the Bible, and they are still in print after over 400 years . </P>

What work written by calvin became the textbook for reformed theology