With the exception of the Bible, no Christian writing has had so wide a vogue or so sustained a popularity as this. And yet, in one sense, it is hardly an original work at all. Its structure it owes largely to the writings of the medieval mystics, and its ideas and phrases are a mosaic from the Bible and the Fathers of the early Church. But these elements are interwoven with such delicate skill and a religious feeling at once so ardent and so sound, that it promises to remain, what it has been for five hundred years, the supreme call and guide to spiritual aspiration.