The girl who has chosen an intellectual pursuit has to be taught before leaving home that the real ethics is the defense of all external sex-values. Man is more than a mere sex-being. The spiritual kind of virginity consists in the sensual affairs not being dominating, exacting or filling the inner life. The Jewish philosopher, Philo of Alexandria in Egypt, says: “The virgin, by her company with man, becomes a woman, by the soul’s association with God, the woman becomes again a virgin.” Such are the lessons the young girl should take along, when she leaves home, so that she may be protected against the doctrines of sensual hyperaestheticism of the modern writers. The necessity of self-control and chastity must be impressed upon the mind not only of the young woman but also of the young man. There is not the slightest support in physiology for the double standard of morality of the two sexes. Either men and women should be allowed to lead a promiscuous sex-life,[CA] or what is by custom forbidden to the woman should not be allowed to the man either. But such lessons will have very little effect upon boys who have passed childhood and puberty before they have had the opportunity of receiving proper sex-instruction. Such boys need altogether another kind of instruction, namely, lessons in personal prophylaxis. The objection that to teach personal prophylaxis against venereal infection would remove the most effective obstacle to sexual indulgence, i. e., the fear of infection, simply shows the ignorance of the elementary force which indulgence in venery, once tasted, drives the boy into the arms of prostitution, fear or no fear.[CB] The young man himself, once defloured of his virginity, is of no concern any longer. All the lessons in personal prophylaxis will not have the least influence upon his conduct in life one way or another. But personal prophylaxis may save his wife and children from a life of invalidism and even death. The same procedure will be necessary in dealing with the young man who is a congenital weakling and has to associate with meretricibus. He should at least take care not to contract any venereal disease, which may wreck the lives of his future wife and children. He should immediately after coition, first wash with a cotton-sponge the penis—head, shank and under-frenum—with a solution of sublimate 1:5000; secondly pass water and make a urethral injection with a solution of 2% protargol, and thirdly rub a 50% calomel ointment well into the fore-skin, head and shank of the penis, particularly about the frenum.[CC] The best prophylaxis against masturbation, and in a certain degree also against inchastity, is the coëducation of the sexes. The familiar intercourse of boys and girls in the kindly presence of their teachers prevents and appeases the morbid craving of the sex-appetite, provided the pupils have not been morally tainted before they entered the coëducational school.