The passing years, which bury so many once-famous names under deep layers of forgetfulness, are raising Matthias Joseph Scheeben to an eminence reached by very few scholars. Time is the judge of all achievements, and has pronounced its verdict that Scheeben is the greatest theologian who has written in the German language. The reason for his importance is not hard to find. Scheeben is the chief theologian of the supernatural economy of the world. The intellectual blight known as rationalism had spread widely in the nineteenth century and had made disastrous inroads even in Christian circles. Although preliminary battles waged by Catholics who were turning back the unholy invasion, Scheeben was the champion who finally and decisively drove the enemy out of theology. From the very outset of his theological career, Scheeben had cherished the ambition of making the drab naturalistic world glow again in the light and beauty of grace, of bringing back to the awareness of men the glorious truth that they are God's children. In the first of his major books, Nature and Grace, he describes the supernatural as a sharing in the nature of God. This same theme, the splendor of our supernatural life, is the leading idea of all his works. He thought that a deep appreciation of the mysteries revealed by God was so important that he consecrated the tireless powers of his genius to the task of bringing out their beauty and force, and of emphasizing their meaning for the daily life of man. He insisted that these mysteries are the richest treasure of our spiritual inheritance and that theology is the inspiration of the fullest lie open to use-supernatural life with Christ and in Christ. Scheeben's masterly theological synthesis is best proposed in The Mysteries of Christianity, his most original work, but was clearly formulated from the beginning of his literary activity in Nature and Grace, the book of his energetic youth.