"Marriage may often be a stormy lake but celibacy is almost always a muddy horse pond." Thomas Love Peacock, 18th Century English poet and novelist.

Celibacy has been dragged through the mire again this week, following the spectacular fall from grace of Cardinal Keith O'Brien. His admission that his "sexual conduct" fell below the standards expected of him, amid allegations of "inappropriate behaviour", has unleashed a predictable outburst about the impossibility of clerical celibacy.

In our sex-drenched age, the very notion of celibacy is alien. Some academics even question whether celibacy in its strictest definition is physically possible. The Oxford Professor of Endocrinology, John Wass, dismisses celibacy as "a totally abnormal state", given that men are driven by testosterone to want sex.

In her book, A History of Celibacy, Elizabeth Abbott observes: "In our sex-dominated society, people tend to view celibacy as a form of sexual anorexia–- a sad and lonely state at best, unnatural at worst." Perhaps we forget how quickly and how utterly Western society has been transformed by reliable contraception and the rise of a sales-based culture in which sex is used to flog everything from lipstick to cars.

Only a few decades ago the criminalisation of homosexual activity, the stain of illegitimacy and the requirements of an economy based on industrial production and agriculture forced celibacy on a large part of the population, whether gay or straight. And even today, many people choose to become or remain celibate for various reasons. Sometimes they simply haven't met "the right person" yet. As we get older, it becomes easier to imagine a celibate life that could also be enjoyable and fulfilling.

Even so, at one extreme celibacy is dismissed as quaint, amusing, irrelevant or eccentric and at the other a deviant perversion or some sort of cruel punishment. In today's Viagra generation, those who admit to being celibate are objects of derision or pity.

As neither a biologist nor a Catholic, I can only comment on what I observe. As with most human attributes, the distribution of libido covers a wide spectrum from those who seem to think of little else but sex to those who never think about it at all.

From this second group, two of the three male friends I'm thinking about became Catholic priests. Neither was a closet homosexual and both made wonderful priests. It's not just that they are free from family constraints to rush off and comfort the dying at 4am. In a very real sense, they have been able to give all of themselves to God, to those they serve and to the least fortunate in society. Neither of these men felt repressed. On the contrary, their celibacy freed them up to love others in a different way.

It must appear odd in a culture where there is a false equation of sexual activity with being human but, looking at the lives of these two men, I can appreciate Pope Paul VI's description of celibacy as a "dazzling jewel" in the crown of the church.

The problem, as Cardinal O'Brien perhaps hinted in a recent interview, is that it is a comparatively rare one. That is why a future Pope should heed the words of St Paul to the Corinthians about it being "better to marry than to burn". After all, St Peter, regarded by Catholics as the first Pope, appears to have been married.

Besides, as Anglican converts to the Catholic church can bring their wives with them, imposing priestly celibacy seems increasingly anomalous. And condemning parish priests to perpetual loneliness is cruel and unfair to the many who must yearn for companionship. But just because most of us would find celibacy difficult, let's not dismiss it as either impossible or outlandish. It is neither.