The neglect of children at this early age is a direct cause of the corruption of the next stage of life. The lad of sixteen or seventeen is in the first flush of early manhood. He is physically capable of becoming a father, although entirely unfit to be so. Some years are required to strengthen his physical powers. The advantage of the self-control of absolute chastity at this period of life is unquestionable; every physiologist will confirm this statement. But chastity is of the mind as well as of the body. The corruption of the mind at this early age is the most fruitful source of social evil in later life. The years from sixteen to twenty-one are critical years for youth. If purity of life and the strength of complete self-control can then be secured, there is every hope for the future. Every additional year will enlarge the mental capacity, and may confirm the power of Will. The strong man is able to take the large views of sex, its uses, aims, and duties, which are considerations too abstract for the child-man, impelled by bewildering sensations. If at this early age he falls, he is too often lost. Physical passion, which reaches its maximum (roughly speaking) at twenty-seven, can only be controlled and exalted if, at the age when chastity is a positive physical benefit, the great mental principle of self-control has gained mastery over the nature. If at this period the power of Will has been gained to retain self-respect and resist temptation, such habit of self-government is the safeguard of youth. It is the only foundation on which the early years of life can be safely based, the only way by which those habits of virtue can be established which strengthen the constitution and enable it to grow into the fullest vigour of manhood. If, however, the child has been injured by habits or associations which produce precocity and irritability of function, he will inevitably fall into vice in the earliest years of manhood; his power of resistance is gone, and every temptation drags him down.