This book would never have been written had I not been honored with an appointment as GiffordLecturer on Natural Religion at the University of Edinburgh. In casting about me for subjects ofthe two courses of ten lectures each for which I thus became responsible, it seemed to me that thefirst course might well be a descriptive one on "Man's Religious Appetites," and the second ametaphysical one on "Their Satisfaction through Philosophy." But the unexpected growth of thepsychological matter as I came to write it out has resulted in the second subject being postponedentirely, and the description of man's religious constitution now fills the twenty lectures. In LectureXX I have suggested rather than stated my own philosophic conclusions, and the reader whodesires immediately to know them should turn to pages 501-509, and to the "Postscript" of thebook. I hope to be able at some later day to express them in more explicit form.

In my belief that a large acquaintance with particulars often makes us wiser than the possessionof abstract formulas, however deep, I have loaded the lectures with concrete examples, and I havechosen these among the extremer expressions of the religious temperament. To some readers I mayconsequently seem, before they get beyond the middle of the book, to offer a caricature of thesubject. Such convulsions of piety, they will say, are not sane. If, however, they will have thepatience to read to the end, I believe that this unfavorable impression will disappear; for I therecombine the religious impulses with other principles of common sense which serve as correctivesof exaggeration, and allow the individual reader to draw as moderate conclusions as he will.

My thanks for help in writing these lectures are due to Edwin D. Starbuck, of StanfordUniversity, who made over to me his large collection of manuscript material; to Henry W. Rankin,of East Northfield, a friend unseen but proved, to whom I owe precious information; to TheodoreFlournoy, of Geneva, to Canning Schiller of Oxford, and to my colleague Benjamin Rand, fordocuments; to my colleague Dickinson S. Miller, and to my friends, Thomas Wren Ward, of New York, and Wincenty Lutoslawski, late of Cracow, for important suggestions and advice. Finally, toconversations with the lamented Thomas Davidson and to the use of his books, at Glenmore, aboveKeene Valley, I owe more obligations than I can well express. Harvard University, March, 1902.