(2) _Moral Influence._ While most Sunday-school books as literature are open to criticism, yet in the realm of ethics they generally present high ideals. The characters depicted in them may not be symmetrical, but on the whole they are earnest and upright. Youth admires heroism; and the personalities portrayed in popular Sunday-school books are generally heroic, even though they may be unduly emotional. The boys who are picked up by the police in railroad centers, armed for fighting Indians or robbing trains, generally carry an assortment of cheap novels, but they are not from Sunday-school libraries. If the criterion be ethics and not literature, most Sunday-school books will stand the test. (3) _Aid to the School._ As has been already suggested, the original aim of the library was to attract scholars to the school. In many places this influence is no longer needed; but there still remain communities where scholars are obtained and families are interested by means of the library. And it is an open question whether if the library had advanced step by step with the other departments of the school, if the same attention had been given to the supply and management of the library as has been given to the educational work, if the right books had been kept upon its shelves, and advanced methods had been sought in their distribution, the library of the Sunday school might not still be a vigorous and successful institution. 5. =Principles of Selection.= If the governing board of the school decides that a library for general reading by the scholars is desirable, the question at once arises as to what principles shall determine the selection of books. A few of these principles may be stated: (1) _Variety._ The library should represent more than one department of literature. So general is the taste for stories that the tendency will be inevitable to overload the library with works of fiction. Therefore special care should be given to include in it the lives of great and good men--heroes, statesmen, explorers, leaders of the church, and missionaries. All of these present life on its romantic side, and may be found written in an entertaining manner. Upon the shelves should also be placed history and science--not in many-volumed treatises for scholars, but in popular books for young people. In fact, there are few departments of a good public library which may not properly be included in the library of the Sunday school, especially in places where the school is expected to supply the reading matter for the community.