I have long been thinking about the problem of unwanted pregnancy. The solution proposed by most of the more old-fashioned Protestant Christians is just to abstain from sexual activity until marriage; and the oft-unspoken advice is to contracept in marriage to limit the number and timely arrival of children. Catholics, with all their fuss against contraception, have an abstain-until-you-are-married-and-want-children approach to this problem. Neither of these approaches deals fairly with the single biggest problem faced by people who don’t want children: unplanned sexual activity.