Christentum als mystische Tatsache und die Mysterien des Altertums. English - Christianity as Mystical Fact was the title given by the author to this work, when, eight years ago, he gathered into it the substance of lectures delivered by him in 1902. The title indicated the special character of the book. In it the attempt was made, not merely to represent historically the mystical content of Christianity, but to describe the origin of Christianity from the standpoint of mystical contemplation. Underlying this intention was the thought that at the genesis of Christianity mystical facts were at work which can only be perceived by such contemplation.
It is only the book itself which can make clear that by "mystical" its author does not imply a conception which relies more on vague feelings than on "strictly scientific statements". It is true that "mysticism" is at present widely understood in the former [iv]sense, and hence it is declared by many to be a sphere of the human soul-life with which "true science" can have nothing to do. In this book the word "mysticism" is used in the sense of the representation of a spiritual fact, which can only be recognised in its true nature when the knowledge of it is derived from the sources of spiritual life itself. If the kind of knowledge drawn from such sources is rejected, the reader will not be in a position to judge of the contents of this book. Only one who allows that the same clearness may exist in mysticism as in a true representation of the facts of natural science, will be ready to admit that the content of Christianity as mysticism may also be mystically described. For it is not only a question of the contents of the book, but first and foremost of the methods of knowledge by means of which the statements in it are made