There is another side to the problem of marriage that points to need of the larger sex-education. Physiology and psychology of sex are fundamental; but they alone are not sufficient to complete that mutual adjustment and understanding which marriage at the full development of its possibilities involves. Matrimonial harmony cannot be entirely a problem of applied science, as some superficial devotees of science seem to think; for science can never analyze those subtle and ever-varying qualities that go to make up what we call personality, and marriage in its largest outlook is the intimate blending of two personalities. Psychological and physiological knowledge will undoubtedly help the two married individuals in their progress towards the harmonious adjustment of their individualities; but there are many little, but often serious, problems that the physiology and psychology of sex cannot solve. They are problems that involve mutual affection, comradeship, sympathy, unselfishness, cooperation, kindliness, and devotion of husband and wife. Obviously, these can never be developed by any formal instruction. [Sidenote: Helpful literature.] Probably there is no better way to help young people realize the possibilities of matrimonial harmony than by suggesting wholesome literature. Some of this is a part of the world's general treasure of books that in prose and poetry, in history and romance, hold up a high ideal of love with marriage. There is much such literature that gives young people inspiration, but too much of it, like college life, ends with a commencement. "And then they were married and lived happily ever after"--is the familiar closing as the novelist rings down the curtain after reciting only the prologue in the life drama of his two lovers. We need more literature that does not end with the wedding march, but which gives young people the successful solution of the problems after marriage. Some such is available in history and biography; some in essays. As I write there come to my mind several books that have impressed me: Professor Palmer's "Life of Alice Freeman Palmer"; Leonard Huxley's "Life and Letters of T.H. Huxley," which gives many intimate glimpses of the ideal home life which the great biologist centered around Mrs. Huxley; William George Jordan's "Little Problems of Married Life"; Orrin Cock's "Engagement and Marriage"; and that much misunderstood[11] but helpful book "Love and Marriage" by Ellen Key. Many of the stories by Virginia Terhune Van de Water, published in the magazines and collected in a book entitled "Why I Left my Husband" (Moffatt, Yard), deal with real problems of married life. [Sidenote: Similar education of the sexes.]