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