I am sure that Lydia Playfoot is a lovely young woman. She certainly seems unlikely to add to the welfare statistics, having pledged to remain chaste until she marries.

But Miss Playfoot’s personal morals are of no relevance to her importance in public policy. Because on Friday Miss Playfoot took her school to court. And it is in all our interests that the judgment, when it is delivered, puts her case where it belongs: in the bin.

Miss Playfoot wears a silver ring, that indicates that she is a virgin. She wears the ring when she is out with friends. She wears it at home. But there is one place where she does not wear it: at school. Her headmaster has banned it.

To Miss Playfoot, this is an outrage. Muslim pupils at Millais School in Horsham are allowed to wear headscarves and Sikh students may wear bangles. Miss Playfoot says that she is being discriminated against, and that the headmaster is wrong to say that her silver ring is not an article of religious faith.

Her counsel argued on Friday that: “Secular authorities cannot rule on religious truth . . . secular authorities and institutions cannot be arbiters of religious faith.” Quite right. It is indeed inappropriate for headmasters to act as judges of religious doctrine. But that is precisely why Miss Playfoot’s case is so wrongheaded – why, in fact, it is the wrong way round altogether. The claim of religious significance should not, in a secular school, privilege a hajib over a silver ring or over a T-shirt proclaiming “I’m a stud”. All are simply forms of self-expression, and it is not relevant which is religious.

We have been here before. Last year Shabina Begum claimed that she should be able to wear a hajib at school because of her faith. The House of Lords correctly held that no such right existed.

Both these cases are, at root, the same. They stem from the dangerous belief that self-described religiously observant behaviour should, for that reason alone, be granted special status in secular areas.

But we do not live in a theocracy. We live in a democracy in which all sorts of differing beliefs share public space. That works only if all claims to special treatment through religion are held in the same regard – as being entirely without merit. I should no more be allowed to behave as I wish because I claim that my religion – the Finchley Church of Pollard Observants – compels me to than should Miss Proudfoot be able to wear her silver ring.

Miss Playfoot does have a case. But it is not the one she wants. It is quite wrong that her school allows some children to dress as they please, in headscarves or with bangles, but prevents Miss Playfoot from wearing whatever she wishes. Her action should have been based on ensuring that other pupils, like her, were prevented from making a statement with their clothing.

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