Next to the origins of Christianity the most controversial of the larger problems of history is the Reformation; and here Protestants of all schools are ranged in a solid phalanx against Catholics. That the Church was in need of reform is agreed by both sides; but the Catholic contends that the evils to be remedied have been fantastically exaggerated, that there was no need for a revolt, and that the revolution inaugurated by Luther left Germany far worse than it found her. Realizing that the Protestant view most authoritatively presented in Ranke's classical work on the Reformation held the field, Janssen compiled a cultural history of the German people from the end of the Middle Ages to the outbreak of the Thirty Years War. Based throughout on original sources, and illustrating his thesis from every angle, his eight massive volumes were hailed with gratitude and enthusiasm by Catholics all over the world. No Catholic historical work of the nineteenth century, and certainly no attack on the Reformation since Bossuet's _Variations of Protestantism_, obtained such resounding success or led to so much controversy.
Janssen's object was to show that the fifteenth century was not a period of moral or intellectual decrepitude, with a few 'Reformers before the Reformation' crying like voices in the wilderness, but an era of healthy activity and abounding promise. He describes the flourishing state of religious and secular education, the vitality of art, the comfort of the peasantry, and the prosperity of the towns. On reaching the sixteenth century, he denounces the paganism of the Humanists and paints a terrible picture of the material and moral chaos into which Germany was plunged by the Lutheran revolt. The later volumes are devoted to the era of the Counter-Revolution and present a canvas of unrelieved gloom, immorality and drunkenness, ignorance, superstition and violence. Thus the story which opened with the bright colours of the fifteenth century closes in deep shadows, and the moral is drawn that Germany was ruined not by the Thirty Years War but by the Reformation.
Protestant historians fell upon the audacious iconoclast with fierce cries of anger, and had no difficulty in exposing his uncritical use of authorities, his habit of generalizing from isolated particulars, and his suppression of facts damaging to his own side. But though it was a dexterous polemic, not a work of disinterested science, Janssen's book has made it impossible for any self-respecting Protestant to write on the Reformation without knowing and weighing the Catholic side. Of similar tendency though of far higher value is the monumental work in which Pastor is narrating the story of the Renaissance and sixteenth-century Popes from the Vatican archives, which neither Ranke nor Creighton had been able to employ. No really objective picture of the Reformation can be painted by Catholic or Protestant; but a good deal of firm ground has been won, and the writings of Kawerau, the greatest of Lutheran scholars, inspire us with a confidence that no writings of the last generation deserved.