Sex was one of the Creator's best ideas. Few things offer more delight: the bodily pleasure of tension and release; the adventure of exploring and knowing another human being; the real, if temporary, liberation from fragmented individualism into intimate communion. In a life often marked by frequent boredom, dreary routines, and hard labor, sex is a blessed interruption--perhaps I should say, a volcanic eruption--of ecstatic joy.

But it, too, has limitations. The most obvious is its dependence on bodies, and these bodies, as we've already acknowledged, must contend with the wear and tear of age.

A friend recently asked a small group of us, "Do you know the best birth control after the age of forty?"

Different answers came to mind but the smile on his face asked us to play along with him. "No, tell us."

"Getting naked."

We laughed, of course. We laughed because we were all over forty and had our share of wrinkles and flab and moles and plumbing problems; we laughed to distract ourselves from the anxiety that had been evoked; we laughed because that's often the best strategy for disarming a threatening truth.

But with our spouses standing next to us, we did not laugh too hard.

It's common knowledge that sexual vigor diminishes with age. Or at least, it has been common knowledge. Now we're questioning this. Research focused on older persons has provided a more accurate picture, one that reveals men and women in their sixties and seventies, even eighties, enjoying an active sex life. Yesterday, in preparation for writing this chapter, I thumbed through sections of The Hite Report on Male Sexuality, and I was enormously cheered to discover what many retired people do with their spare time! The consensus among Hite's interviewees seems to be that though sexual activity changes over time, its desire and pleasure remain. Reading about this reminded me of something my white-haired dad likes to say: snow on the roof doesn't mean there can't be fire in the furnace.

Still, most couples report some flagging of interest and performance overtime. And, regardless of age, even the most ready-to-get-it-on couples have to admit inevitable limitations. They may shake loose the bedsprings three or four times a day, but there comes a time when even champions of libido need a break. The body can take only so much pleasure. Besides, the bills need to be paid and the garbage taken out.

And many are simply not able to have sex, no matter how much they want it. Perhaps they're single, with no romance in their lives; perhaps their spouses are ill or uninterested; perhaps they can't transcend debilitating emotional hurdles; perhaps they're too wounded from past experiences; perhaps they have no energy left after raising children and making a living. There are many reasons why people undergo involuntary celibacy. In fact, it's fair to assume that all of us, at one time or another, endure this.

The limitations of sex are so obvious, I hardly need to belabor the point.

So what possible consolations could be found in the diminution of something so wonderful?

For one thing, these limitations provide time to think about other things. Meager compensation, you might say. But consider this: the average male thinks about sex six times an hour. On a slow day. Now, if you deduct eight hours a night for sleep, much of which is spent dreaming about sex, and multiply the remaining sixteen hours a day by a lifetime of seventy years, you end up with 2,446,080 thoughts about sex. This is the average as I said. Which is why some of you are now thinking, Only six times an hour? Some of the brothers aren't pulling their load!

I wouldn't presume to speculate how often women think about sex, but if the statistics are anywhere near the other half of the species, it's a wonder the human race has had the mental wherewithal to build bridges, write novels, and perform open heart surgery. We should probably thank the limitations of sex for these things; they provide a valuable service, releasing us, at least briefly, to be more attentive to other things-things good and beautiful and productive but without the gravitational pull of sex.

And when it comes to the unconscious, we can only hope and pray the limitations of sex provide a respite for this, too. Deep within everyone is a boiling, roiling, overflowing cauldron of sexual emotions-longing, fear, guilt, anxiety, fantasy, pain, and happiness-and this constantly spills over into our lives, even parts that seem to have nothing to do with sex. It's the cause of much confusion and heartache. If the limitations of sex do nothing more than provide an occasional calming of this inner turmoil, they deserve hearty praise.

There is another, more significant consolation: the limitations of sex enable us to become more, not less, erotic. This will take some explaining, I know.

The psychotherapist Rollo May, in his influential book Love and Will, has helped me understand that sex can actually be separated from eros; it can, moreover, be set over against eros: "We are in flight from eros-and we use sex as the vehicle for the flight.We fly to the sensation of sex in order to avoid the passion of eros."

Our culture proclaims loudly that anxiety about sex is archaic and encourages us to be free in our love. But May asks, "What of the anxiety which comes precisely from this new freedom?" The capacity for personal choice can create a heavy burden. Since nowadays everyone ought to feel free and uninhibited, anxiety has no way to act itself out externally, and thus it turns inward, inhibiting feelings and suffocating passion. Sex becomes a means of escaping the costly involvement of passion, a way to flee from the risks of total engagement with another. "We go to bed because we cannot hear each other; we go to bed because we are too shy to look into each other's eyes, and in bed one can turn away one's head."