As I appear before the public with a new edition of my Church History, I feel more than ever the difficulty and responsibility of a task which is well worthy to occupy the whole time and strength of a long life, and which carries in it its own rich reward. The true historian of Christianity is yet to come. But short as I have fallen of my own ideal, I have done my best, and shall rejoice if my efforts stimulate others to better and more enduring work. History should be written from the original sources of friend and foe, in the spirit of truth and love, "sine ira et studio," "with malice towards none, and charity for all," in clear, fresh, vigorous style, under the guidance of the twin parables of the mustard seed and leaven, as a book of life for instruction, correction, encouragement, as the best exposition and vindication of Christianity. The great and good Neander, "the father of Church History" first an Israelite without guile hoping for the Messiah, then a Platonist longing for the realization of his ideal of righteousness, last a Christian in head and heart made such a history his life-work, but before reaching the Reformation he was interrupted by sickness, and said to his faithful sister: "Hannchen, I am weary; let us go home; good night!" And thus he fell gently asleep, like a child, to awake in the land where all problems of history are solved. When, after a long interruption caused by a change of professional duties and literary labors, I returned to the favorite studies of my youth, I felt the necessity, before continuing the History to more recent times, of subjecting the first volume to a thorough revision, in order to bring it up to the present state of investigation. We live in a restless and stirring age of discovery, criticism, and reconstruction. During the thirty years which have elapsed since the publication of my separate "History of the Apostolic Church," there has been an incessant activity in this field, not only in Germany, the great workshopof critical research, but in all other Protestant countries. Almost every inch of ground has been disputed and defended with a degree of learning, acumen, and skill such as were never spent before on the solution of historical problems.