Martin Luther posted his Ninety-five Theses on the church door at Wittenberg in 1517. In the three years that followed, Luther clarified and defended his position in numerous writings. Chief among these are the three treatises written in 1520. In these writings Luther tried to frame his ideas in terms that would be comprehensible not only to the clergy but to people from a wide range of backgrounds. To the Christian Nobility of the German Nation is...