To show you the influence of ego development in the formation of a conflict, and so to give an illustration of the causation of neuroses, I should like to cite an example which, although it is entirely imaginary, is not far removed from probability in any respect. Drawing upon the title of a farce by Nestroy, I shall label this example "On the ground floor and in the first story." The janitor lives on the ground floor, while the owner of the house, a rich, distinguished man, occupies the first story. Both have children, and we shall assume that the owner permits his little daughter to play unwatched with the child of the people. Then it may easily happen that the games of the children become "naughty," that is, they assume a sexual character; they play "father and mother," watch each other in the performance of intimate performances and mutually stimulate their genitals. The janitor's daughter, who, in spite of her five or six years of age, has had occasion to make observations on the sexuality of adults, probably played the part of the seducer. These experiences, even though they be of short duration, are sufficient to set in motion certain sexual impulses in both children, which continue in the form of onanism for several years after the common games have ceased. So far the consequences are similar; the final result will be very different. The janitor's daughter will continue onanism possibly to the commencement of her periods, abandon it then without difficulty, not many years later find a lover, perhaps bear a child, choose this or that path of life, which may likely enough make of her a popular artist who ends as an aristocrat. Perhaps the outcome will be less brilliant, but at any rate she will work out her life, free from neurosis, unharmed by her premature sexual activity. Very different is the effect on the other child. Even while she is very young she will realize vaguely that she has done wrong. In a short while, perhaps only after a violent struggle, she will renounce the gratification of onanism, yet still retain an undercurrent of depression in her attitude. If, during her early childhood, she chances to learn something about sexual intercourse, she will turn away in explicable disgust and seek to remain innocent. Probably she is at the time subjected anew to an irresistible impulse to onanism, of which she does not dare to complain. When the time arrives for her to find favor in the eyes of a man, a neurosis will suddenly develop and cheat her out of marriage and the joy of life. When analysis succeeds in gaining insight into this neurosis, it will reveal that this well-bred, intelligent girl of high ideals, has completely suppressed her sexual desires, but that unconsciously they cling to the meager experiences she had with the friend of her childhood.