In my Quakers in the American Colonies I announced the preparation of a volume to be devoted mainly to Jacob Boehme and his influence. I soon found, however, as my work of research proceeded, that Boehme was no isolated prophet who discovered in solitude a fresh way of approach to the supreme problems of the soul. I came upon very clear evidence that he was an organic part of a far-reaching and significant historical movement -- a movement which consciously aimed, throughout its long period of travail, to carry the Reformation to its legitimate terminus, the restoration of apostolic Christianity. The men who originated the movement, so far as anything historical can be said to be "originated," were often scornfully called "Spirituals" by their opponents, while they thought of themselves as divinely commissioned and Spirit-guided "Reformers," so that I have with good right named them "Spiritual Reformers."

I have had two purposes in view in these studies. One purpose was the tracing of a religious movement, profoundly interesting in itself, as a great side current of the Reformation. The other purpose was the discovery of the background and environment of seventeenth century Quakerism. There can be little doubt, I think, that I have here found at least one of the great historical sources of the Quaker movement. This volume, together with my Studies in Mystical Religion, will at any rate {vi} furnish convincing evidence that the ideas, aims, experiences, practices, and aspirations of the early Quakers were the fruit of long spiritual preparation. This movement, as a whole, has never been studied before, and my work has been beset with difficulties. I have been aided by helpful monographs on individual "Reformers," written mainly by German and French scholars, who have been duly credited at the proper places, but for the most part my material has been drawn from original sources. I am under much obligation to my friend, Theodor Sippell of Schweinsberg, Germany. I am glad to announce that he is preparing a critical historical study on John Everard and the Ranters, which will throw important light on the religious ideas of the English Commonwealth. He has read my proofs, and has, throughout my period of research, given me the benefit of his extensive knowledge of this historical field. I wish to express my appreciation of the courtesy and kindness which I have received from the officials of the University Library at Marburg. William Charles Braithwaite of Banbury, England, has given me valuable help. My wife has assisted me in all my work of research. She has read and re-read the proofs, made the Index, and given me an immense amount of patient help. I cannot close this Preface without again referring to the inspiration of my invisible friend, John Wilhelm Rowntree, in whose memory this series was undertaken.

HAVERFORD, PENNSYLVANIA,

January 1914.