One small experiment in turning a blind eye and trying to keep sex workers off the streets, by allowing them spaces in which to work, could soon be over.

For some this will be a cause for celebration: one more step towards zero tolerance; towards a world where sex is no longer a thing that can be bought and sold; where men will no longer feel that a wad of cash can purchase a woman's body. But that's not what I feel.

Earlier this year, I talked to sex workers and visited a sauna, and I can't pretend I felt comfortable with what I found.

What I saw wasn't horrifying: a few healthy looking girls, some of them Thai, mostly in their early twenties, sat around on sofas, beaming a synchronised smile. It was hard to work out if my anxiety came from years of drummed-in moral disapproval. In any case, it seemed important not to let that cloud my perceptions of whether these women were mostly doing something they wanted to do with their own bodies, voluntarily, and without coercion - though at the same time plainly for cash. When I later spoke to sauna workers, that's what they said was the case.

When it comes to dealing with Scotland's sex trade, most people are on one or other side of a great divide. They either see prostitution as a fundamental wrong that should be eradicated, or as the world's oldest profession, unavoidable and eternal - and therefore needing to be made as safe as possible. I don't advocate either view. I believe in people's right to decide what they do with their own bodies, even if it's for money. I believe in helping women get out of prostitution if that's what they choose, but not driving them out.

Tolerance, particularly when it comes to people's sexual habits, is one of the principles of our times. Gradually our society is coming to accept what people do with their own and other people's bodies, so long as it's consensual and not underage. Same-sex, multiple partners, affairs, threesomes, fetishes: these are treated as a subject for gossip rather than moral contempt. You can have 10 partners a week, so long as there's no money exchanged. But prostitution remains beyond the pale. We feel that people who have done it have crossed a boundary and are worthy of pity and concern. These women are stigmatised and marginalised. With prostitution, talk of tolerance usually comes with the word "zero" attached.

It is doubtful that the people running saunas - some of them women - will retreat from the sex industry altogether if they are no longer given licences. Rather, they will probably join the hosts of pimps and brothel-keepers operating out of private flats, and more discreet locations. As for the sex workers, some, through the "exit services" currently being proposed by Edinburgh City Council, may leave the industry, others may end up on the street. But I imagine most will continue, working out of flats, picking up clients over the internet as they have done for some time.

What will happen to them there? Is it a less safe, more risky world? Probably. Statistics suggest around 48% of "indoor workers" (those operating in saunas and flats) report having experienced violence. That compares with 81% of those working the streets. But this is old research from 2001. There is no study that distinguishes between flats and saunas, though anecdotally many claim flats are more dangerous. One escort I talked to described how risky it felt to go to someone's house, and recalled a violent assault she experienced when working for an agency which "wasn't very good at checking people out".

Like many people, I feel uncomfortable with prostitution. But there is one thing I fear more than a world of super-brothels and the ubiquitous advertising of sex work, and that is its opposite: a world where sex work is driven underground, where it becomes part of the secret world of our society, unacknowledged, unspoken of, yet still practised by many.

Such a climate does not make women safer. Instead it further marginalises them and enhances the impression that they belong to a hidden world of the disposable. And I would rather be faced with loud and noisy sex workers with rights and unions, than a society where women are treated as throwaway commodities.