GERMAINE GREER’S appearance on Celebrity Big Brother has become the first cultural mystery of 2005. Why is she doing it?

Why would a celebrity with neither an impending nervous breakdown nor a burning desire to reinvent themselves as a light entertainment presenter volunteer themselves for two weeks of wading through fish guts to “win” four pints of milk and a couple of dozen column inches?

Greer claims it is to earn money for her chosen cause and, indeed, the invertebrate conservation charity Buglife probably do not have a great many high-rolling donors. For those bugs, Germaine on Celebrity Big Brother probably is their last hope.

But is what Germaine feels for the hapless cnidarian — the invertebrate with no anus and, therefore, one would presume, the one currently facing the most trouble — enough for her to risk her reputation? On Saturday night, when Greer found herself sitting on a roundabout with a bowl strapped to her head, trying to win a week’s worth of bread whilst being sprayed with rancid milk, she must have wondered if she did care about those invertebrates as much as she thought she did.

After all, next time she has a stand-up row with Suzanne Moore (“Three fat inches of cleavage”), Moore will be able to reply that at least she has not ever had to explain how to cure diarrhoea to the racing commentator John McCririck (“Pysillium makes a big, bland mucilage”) and so must be just that bit cleverer than Germaine.

But then, I wonder if Germaine has achieved that level of cleverness that means that everyone stupider than her comes, ironically, to believe that she is the stupid one.

First, there is not a great deal of good being a strong, intelligent, fearless feminist if the very people who need to witness your intellectual rigour the most — 14-year-old girls in scrunchies, who are considering becoming single mothers “for something to do” — have never heard of you.

By appearing on Celebrity Big Brother, Germaine has been able to inject herself right into a needful constituency, while saving millions of endangered flat worms. Go, girlfriend! Additionally, reality TV is the prime cultural currency of this country in 2005. Its cycles of vilification, mortification and redemption allow us to examine what we really feel about a number of difficult issues (transsexuals, cheating, Les Dennis), while simultaneously deciding who “deserves” to be famous (transsexuals, cheaters, not Les Dennis). It is an enormously powerful, if ultimately meaningless, mechanism.

Perhaps Germaine decided that, as a cultural and political commentator, she should examine the whole reality TV phenomenon from within — gain an understanding of its workings by smuggling herself into the machinery, albeit with a bucket on her head.

Or, maybe, she was just a bit lonely on her farm with all those geese. It has, after all, been a long, cold winter, and they do have a hot tub in the Big Brother house.