All parents at some time, and some parents at all times, regard boys as necessary evils, to be endured with varying degrees of patience. We formerly believed that boys should be seldom seen and less frequently heard. The young barbarian was and is now tolerated for the time being because of our hope that he will outgrow his rowdyism. We are disposed to let nature take its course with the juvenile savage instead of bothering our heads with the effort to understand him or to solve his problems. But to train the boy intelligently we must first train ourselves so that we can understand him and guide him through the various stages of his development. Intelligent training is the birthright of every child. If he has not received it, he has been cheated. The training of the child up to perfect maturity is the highest duty as well as the most difficult task which devolves upon parents. The performance of this duty is, fortunately, lightened by the pleasure of association with the joyousness of childhood, but the real reward of the parent for years of patient, watchful, intelligent supervision is not only the consciousness of duty well done but the profound joy experienced in aiding the unfoldment of an immortal soul. The study of childhood possesses a fascination for the student commensurate with its importance to humanity. It is both easier and pleasanter to study the child in the concrete than children in the abstract. But it is obvious that no comprehensive conclusions on the subject of child-training can be deduced from the study of a single child. The varying manifestations of different natures and temperaments require wide observation, covering many subjects, before correct conclusions as to cause and effect can be drawn or a systematic philosophy can be evolved. We must study the concrete boy in large numbers to be able to formulate abstract principles of boy-training. “The proper study of mankind is man,” may be paraphrased into “the proper study of boykind is boy.” Today we know the boy better than ever before. He has been studied, watched, weighed, analyzed, synthesized, tested, classified and labeled in all his varied aspects. We have transformed our personal knowledge of him into scientific knowledge; and various manifestations of his activities which were formerly called “pure cussedness” are now recognized as ebullitions of superabundant vitality which have been denied a natural outlet and therefore find expression in prohibited forms.