Grundtvig's hope for a season of quiet and peaceful cooperation with his friends was, however, soon shattered. In the summer of 1825, a young professor of theology, H. N. Clausen, published a book entitled: _The Constitution, Doctrine and Rituals of Catholicism and Protestantism_. As Prof. Clausen enjoyed a great popularity among his students and, as a teacher of theology, might influence the course of the Danish church for many years, Grundtvig was very much interested in what he had to say. He obtained the book and read it quickly but thoughtfully, underscoring the points with which he disagreed. And these were numerous. At the very beginning of the book, he found the author asserting that "the Protestant theologian, since he need recognize no restriction of his interpretations by creeds, traditions, or ecclesiastical authorities, is as once infinitely more free and important than his Catholic colleague. For as the Protestant church unlike the Catholic possesses no conclusive and authoritative system of belief either in her creeds or in Scripture, it devolves upon her trained theologians to set forth what the true teachings of Christianity really are. "Why, O why!" the professor exclaims, "should eternal Wisdom have willed revelation to appear in a form so imperfect? What other purpose, I ask you, can an all-wise Providence have had with such a plan than to compel the children of man to recognize that it is only through the exercise of their own, human intelligence that the revelation of God can be comprehended!" As Grundtvig mused upon these assertions so expressive of all that he had denied and fought against, he felt at once that they constituted a challenge which he could not leave unanswered. He had shortly before written to a friend: "Since the perverters of Christianity have become so self-confident that they will not answer any charge against them except when it is addressed to themselves personally and by name, one may eventually have to employ that form of attack." And that was the form he chose to use in his now famous book. _The Reply of the Church to Prof. H. N. Clausen_. "By the publication of this book," he writes, "Prof. Clausen has put himself forward as a leader among the enemies of the church and the perverters of God's word in this country. A church, such as he advocates, that has no determinable form, exists only in the brains of the theologians, and must be construed from theological speculations on the basis of a discredited Bible and according to the changing thoughts and opinions of man, is plainly nothing but a fantastic dream, a comic if it were not so tragic conception of a Christian congregation which claims to confess the same faith, but knows not what it is, and holds that it is instituted by God, but cannot tell for what purpose before the theologians have found it out.