GEISHA: The Secret History of a Vanishing World, by Lesley Downer. London: Headline Books, 2000, 370 pp., 20 British pounds.

A common question asked about geisha is: Do they or don't they? Their attraction seems balanced between artistic prowess and sex appeal, but just how often is the latter properly appreciated, when and by whom? This and many other questions regarding the geisha are satisfied in this remarkable history of the world of flowers and willows.

As regards whether they do it or not, the answer is "sometimes." Though geisha are bought entertainers, they can refuse -- but since they are also often bound by ties of financial obligation, they cannot continue to do so. Without someone to take care of them, they financially languish. In other words, they are just like stay-at-home wives who also need steady employers -- husbands.

The geisha has to attract someone wealthy enough to provide for her. That he is also always someone else's husband is neither here nor there. She is traditionally no more interested in marriage than she is in love. She is married to her profession, but it does not pay enough.

This accounts for her sometimes precarious social position. She is certainly not a prostitute and cannot be subject to society's disapproval. But she is also not a wife -- at least not usually -- and cannot thus benefit from society's approval either. Her position has always been ambiguous.

It is this delicate balance that Lesley Downer deftly explores. As she says, researching the book was a bit like stalking wildlife, winning the confidence of the geisha, extracting their stories, finding her way around the hierarchical, stratified society that is their world.

"It is a little like Hollywood," she writes. You see only the public face since "the private life of the geisha is . . . utterly closed to outsiders." Outside, "the meter clicks on," she is at work, earning an hourly wage. Inside, it is a life filled with special demands, special obligations.

One of these is that rite of passage euphemized as "mizuage" -- compulsory deflowering. In earlier days, it happened at 14, though Downer quotes one elderly geisha as saying "I was late, I was 15, I was embarrassed." It was something everyone took for granted. "Like a young man's circumcision, painful but unavoidable, it was an initiation ritual," writes the author. "A virgin geisha would have been as much a contradiction in terms as a virgin wife."

The perpetrator was often the elderly and always wealthy gentleman who had agreed to look after the youngster. It was one of the most lucrative transactions in the girl's entire career and vast sums were spent. If a keeper was not found, other means were at hand. These were "professional deflowerers." When a girl was "getting past her sell-by date . . . the mother of her geisha house would go to one of them and suggest he do the honors."

Abhorrent as this may now seem, says Downer, it must be viewed in context. "One way or another, most Japanese women who grew up before 1958 wound up having to have sex with someone they barely knew and didn't care about." This was as true of girls in arranged marriages as it was of girls undergoing mizuage.

After 1958 this changed, at least nominally, with the passing of the antiprostitution bill and the closing of the licensed quarters. Though the anomalous position of the geisha allowed her to escape the ban, sex itself was never again the casual affair that it had been.

Also, the geisha houses were being challenged by a new breed -- the so-called pillow geisha, ex-prostitutes who had managed to escape the law by learning to plunk the shamisen a bit and bungle through a few classical dance steps. In addition, there were the enormous changes brought by postwar modernization.

There are now very few geisha and, one would hazard, even fewer customers. As one told Downer: "There are hardly any guests who understand our arts. One geisha gave up and became a maid in a hotel. She used to be one of the most famous dancers in Atami."

The arts distinguished the geisha -- her grasp of traditional music and dance, her comprehension of the elaborate etiquette that ruled her world, her discretion and her conversation. Now none of this is valued, and the geisha has become a mere curiosity.

An old shamisen maker told the author, "I hope the flower and willow world survives. Without it, life will be lonely and dull. Japan will be just another Hong Kong, nothing but neon." But the oldest geisha in Shimbashi, now 90, said it was worse than after the earthquake, worse than after the war. "It's not just that business is bad. It's the end."

Since it obviously is, the time has come to collect the lore, to listen to those voices we can still hear, and to re-create on paper what this fantastic world was like. Downer does this and the profession can count itself fortunate that it has such a fair, candid and objective observer.

And one who writes so well. Townsend Harris' Okichi "jumped into the sea, having done her bit for international relations." Tea ceremony is "somewhere between tai chi and the Roman Catholic mass but on a very small, intimate scale." The result is a beguiling, enlightening and, in its way, edifying book.