A Little Book of Wisdom by Henry Suso
Henry Suso (1295 - 1329) was a German Dominican friar and is thought to be the most popular vernacular writer in the fourteenth century, by the number of surviving manuscripts. He was an important author in Latin and Middle High German. He is also known for defending Meister Eckhart's legacy. He was beatified by the Catholic Church in 1831.
This work is his second and most famous book, "The Little Book of Eternal Wisdom", which was written around 1328-1330. It is less speculative and more practical. It was soon translated into Latin by the author, who added considerably to its contents. This book was dedicated to the new Dominican Master General, Hugh of Vaucemain, who must have been a supporter of his efforts.