Kiddushin, Chapter Four, Mishnah Thirteen
In yesterdays mishnah we learned some of the laws which prohibit a man from being alone with a woman. As we saw, the assumption was that men cannot control themselves around women and women will not be able to ward off the men. Our mishnah and the next contain discussions of which professions are appropriate for men in light of these assumptions.
1) An unmarried man must not learn to be a scribe, nor may a woman learn to be a scribe.
2) Rabbi Elazar says: even one who has no wife should not learn to be a scribe.
Section one: Part of a scribes work was to teach children how to read and perhaps how to write. In those days, it was often the childs mother who would bring the child to school. Hence the teacher would have a lot of contact with the childrens mothers. Therefore, a man who has never been married should not learn to be a scribe/teacher, lest he come into too much contact with the mothers. Furthermore, sometimes men would bring their children to school. Hence, women and even married women should not be teachers. Note the difference in the halakhah between men and women. Only a man who has never been married may not work as a teacher. Once he is married he will be better able to control himself, for one of two reasons: 1) he has a place to channel his sexual energy; 2) his wife will watch over him. However, even a married woman should not be a teacher, because the men will make advances on her (even if they are married) and she will not be able to ward them off.
Section two: Rabbi Elazar adds that not only a man who has never been married but even one who currently does not have a wife should not work as a teacher. Although he was once married, he will still have the same lack of sexual control and therefore should be controlled by the halakhah.