Ordinarily it will be enough for the purpose to analyze a story along the lines of human instinct as it has been modified by our society and our surroundings and conventionalized by habit. The publishers of Eleanor H. Porter’s novel _Oh, Money! Money!_ were not only wholly correct but quite sufficiently acute in their six reasons for predicting--on the character of the story alone--a big sale. The first of these was that the yarn dealt with the getting and spending of money, “the most interesting subject in the world,” asserted the publishers--and while society continues to be organized on its present basis their assertion is, as regards great masses of mankind, a demonstrable fact. The second reason was allied to the first; the story would “set every reader thinking how _he_ would spend the money.” And the third: it was a Cinderella story, giving the reader “the joy of watching a girl who has never been fairly treated come out on top in spite of all odds.” This is a powerful appeal to the modified instinct of self-preservation. The fourth reason--“the scene is laid in a little village and the whole book is a gem of country life and shrewd Yankee philosophy”--answers to the social hunger in the human heart. Fifth: “A charming love theme with a happy ending.” Sixth: “The story teaches an unobtrusive lesson ... that happiness must come from within, and that money cannot buy it.” To go behind such reasons is, for most minds, not to clarify but to confuse. Folks feel these things and care nothing about the source of the river of feeling. 11 With the non-fictional book the internal factor making for large sales is as diverse as the kinds of non-fictional volumes. A textbook on a hitherto untreated subject of sudden interest to many thousands of readers has every prospect of a large sale; but this is not the kind of internal factor that a publisher is likely to err in judging! Any alert business man acquiring correct information will profit by such an opportunity. But there is a book called _In Tune with the Infinite_, the work of a man named Ralph Waldo Trine, which has sold, at this writing, some 530,000 copies, having been translated into eighteen languages. A man has been discovered sitting on the banks of the Yukon reading it; it has been observed in shops and little railway stations in Burmah and Ceylon. This is what is called, not at all badly, an “inspirational book.” Don’t you think a publisher might well have erred in judging that manuscript? Mr. Trine’s booklet, _The Greatest Thing Ever Known_, has sold 160,000 copies; his book _What All the World’s A-Seeking_, is in its 138,000th. It will not do to overlook the attractiveness of these titles. What, most people will want to know, is “the greatest thing ever known”? And it is human to suppose that what you are seeking is what all the world is after, and to want to read a book that holds out an implied promise to help you get it.