SEX REVOLUTION AND THE TIDE OF HISTORY. In 1876, at the Philadelphia Exhibition, one of the nation’s first centennial birthday presents to itself was the first public display of the rubber condom, the male contraceptive that was a product of a new technique – the vulcanization of rubber. The birth control age did not get under way in earnest, however, until the late 1920s, when, with the latex rubber technique, skin-thin condoms could be mass-produced and mass-distributed very cheaply. Since then, development of spermicides, the diaphragm, the Pill, and the IUD have expanded the techniques of contraception; and since then vasectomy, tubal ligation and early abortion have become less socially stigmatized. Further technical improvements in both male and female contraception are still being researched.

Conception control, like the control of fire-making in an earlier epoch, profoundly affects your life-style, whoever you are and wherever you are. It sets you apart in history, among the first two generations of human beings who are able, after puberty and prior to the menopause, to separate recreational from procreational sex and to begin your recreational sex life in a betrothal relationship (Chapter 4) while preparing yourself for parenthood.

The human race is noteworthy for being unable either to discard its new cultural artifacts, once they have been discovered or invented, or to fully assimilate them without divisive factionalism and onerous struggle over change versus preservation of the status quo. The struggle to formulate a new morality of nonpromiscuous sexual partnerships that are recreational rather than procreational touches all of our lives. It is particularly acute during adolescence, when it can be the source of cruelly abrasive power struggles between parents and teenagers. They are struggles that cannot be legislated away and, quite apart from the invention of contraception, the idea of recreational sex is not a whimsical irresponsibility of some morally degenerate imagination. Rather it is a technically feasible possibility that has become an urgent moral imperative in a world that is increasingly overpopulated and already has begun to experience the effects of overexploiting its ecological resources.

Overpopulation is to some extent a by-product of twentieth-century medical technology, which has increased the life expectancy from the fifth to the eighth decade since 1900. The death of a young parent no longer terminates childbearing to the extent that it used to.

At the beginning of the life span, reproductive fertility begins sooner than it used to. The reasons are unclear, but the statistics are not: the age of puberty has been lowering by four months every ten years for the past century and more. In the eighteenth century, when J. S. Bach was organist and choirmaster at St. Thomas Church in Leipzig, the choirboys sang soprano until age seventeen or older. Today their voices break at age twelve or thirteen. In times past, the interval between puberty in late teenage and legal adulthood at age twenty-one did not put too great a demand on youth with respect to establishing a sexual partnership and parenthood. The onset of normal puberty today can be as young as age nine in girls and eleven in boys. It is unreasonable to expect these young people to wait until their early twenties, when they are academically and economically prepared for parenthood, before they establish themselves in a romantic and erotic pair-bond.

Earlier puberty, increased longevity, world population excess – these are currents in the tide of history that sweep over us in the age of birth control and leave us with no choice except to work out a new ethic of recreational and procreational sex....

Even as recently as the era of the American Revolution, the expected life span, even for those who belonged to the 50 percent who survived the first five years of life, was as low as thirty-five years.