The history of printing in the sixteenth century does not lend itself to a neat Protestant-versus-Catholic interpretation. In the first place, Catholics themselves soon became purveyors of the printed word. Luther's New Testament of 1522 was answered by Hieronymus Emser of Dresden, who in a brief period of time was able to produce a counter-Bible in German shorn of Luther's evangelical marginalia. In 1539, Jacopo Cardinal Sadoleto wrote a public letter to the magistrates and citizens of Geneva entreating them to return to the Catholic faith, to which Calvin responded later in the same year with a stout defense of the Protestant position. In 1516, the Fifth Lateran Council had forbidden the printing of any new volume without the explicit approval and imprimatur of Rome, but this decree could not be enforced. Just so, Sebastian Castellio's interpretation of the Song of Songs did not please the ministers of Geneva, but he fled to Basel, where he was appointed professor of Greek and published many works, including some against Calvin and Beza, with relative impunity, which added to the tension between the two cities. Censorship was interconfessional in the age of the Reformation. At the same time, the Frankfurt book fair continued to be a popular meeting place for publishers and book agents of all kinds, Catholic and Protestant alike, a notable case of capitalism trumping theology.