While the copying of books was the general employment of the brotherhood and of the order, there was from the first a good deal of independent authorship among them, and always on the lines of the “modern devotion.” Groote himself labored chiefly by preaching and correspondence. But some of his letters are tracts in that form, and had a wide circulation as such. Florens was not much even of a letter-writer, but he wrote one devotional tract which has been discovered. It was in Gerard Zerbolt of Zutphen, his _altera manus_, that he found a fit organ for the expression of his ideas in writing. To us Protestants Zerbolt is memorable as the author of a treatise asserting the right and duty of unlearned men to have good books—the Bible and their prayer-books included—in their own tongue. But he was much better known by his writing certain widely circulated books of devotion—modern, of course. Hendrik Mande, the Seer, was a Windesheim monk whose mysticism took the bolder and more ecstatic flight of Rusbroek, and like Rusbroek he found his native tongue more suitable than Latin. Lastly, Gerlach Peterszoon, sometimes called “the second Thomas à Kempis,” although he died in 1411, before Thomas himself had become an author, wrote in both Latin and Dutch sundry works, one of which still is reprinted for edification even by Protestants. Through all this literature runs the same strain of thought and feeling, in spite of personal differences. They all insist on a deeper renunciation of the world than is satisfied by any external monastic compliances. They all hold forth the imitation of Christ’s humility and meekness as the essence of the Christian life. They all insist on devotion to the will of God and good-will to men as the two essential channels in which the Christian life must run.