(2) The second aim is general intelligence. Sex is a universal element in all living beings, with the exception of the very lowest; it pervades the life of the spirit as well as the life of the body. No man, therefore, can be intelligent concerning things in general without a clear, definite and accurate knowledge of the fundamental facts of sex. One of the strongest new visions concerning sex is the marvelous way in it ramifies into all fields of thought and action. Not a few of the most eminent workers in modern science incline to consider all aspects of human life, including even religion itself, as emanations or processes from the sex basis. Such in particular are G. Stanley Hall in America and Freud in Germany. Without going to such extremes we may still recognize the fact that in all sorts of physical and psychic problems in morals, religion, and sociology, sex plays an important part and must be understood if we are to grasp the situation and its meaning.[31] (3) The third aim is social enlightenment. The human spirit in our own day is manifestly addressing itself to the solution of the special social problems which involve the sexual life of men. Three of these problems may be specified: (a) The so-called "social evil," including not merely prostitution, but also all other forms of waste and injury through sexual errors; (b) the problem of family life, including marriage and the rearing of children, as well as pathological aspects such as desertion and divorce; (c) the vast problem of eugenics or race culture. In all these fields the problems of sex are involved. Men and women who desire to bear their whole burden as members of a progressive society must contribute to the solution of these great social problems, and to do this wisely must know something about the basic facts of sex life.[32] The first and basic part of sex education is bodily regimen: children and youth must live an abundant, vigorous, wholesome physical life.[33] Cities have threatened to be the "graves of the human species" in this respect. Sedentary life chokes and misdirects the currents of nervous energy and the very circulation of the blood. The lad who plays vigorously, even violently; who can "get his second wind," turn a handspring, do a good cross-country run, swim the river, possesses a great bulwark of defense against sexual vice, especially in its secret forms. The revival of play, of play for all, boys and girls, weak as well as strong, is one of the most hopeful movements on foot to-day. Let us base our promotions from grade to grade, and especially for "graduation" from school, partly upon physical tests, requiring each student to make of himself physically, not a record-breaking athlete, but the best that can be made out of the stuff in him.