As every one knows, psychology is a word to conjure with. We have today the Psychology of Art, the Psychology of Business, the Psychology of Advertising, the Psychology of Childhood, of Adolescence, and of Old Age, the Psychology of various great men and of various centuries and epochs, until one stands quite aghast at the psychological insight of our times, and feels that the key to everything and anything worth knowing must surely be in the hands of the omniscient psychologist. In fact, psychology would seem to have enlarged her bounds at the expense of every other subject, and to have chosen all knowledge to be her province; so that he who desires his book or treatise on any subject whatever to be regarded as strictly “modern” and “scientific” must needs endow it with a psychological title. This is indeed a short and easy method of becoming a psychologist; and the result is— as one might expect—that all the psychology contained in many of these works is spread, usually in large letters, upon the titlepage. All is not gold that glitters; neither is every treatise psychological which bears that mystic word upon its cover.In no field of serious inquiry are these remarks more pertinent than in that of religion. Our book-shelves and our periodicals are laden with works on “religious psychology,” most of which prove on examination to be hardly more psychological than anatomical or geographical. Treatises on theology and statistics, on Church history and Sunday-school methods, as well as that large and amorphous class of writings which twenty years ago would have appeared under the title “Philosophy of Religion”—all these are now pressing themselves upon our attention by the use of that potent shibboleth, “Psychology.” And yet, though one-half the works with titles of this nature have not much more to do with genuine psychology than with the weather, there is, I believe, a young branch of scientific inquiry which rightly deserves the name Psychology of Religion.