The mother jailed for lying has walked free. Paul Vallely thinks we're addicted to fibbing; Virginia Ironside says that stinks
It wasn't the lie that caused the trouble; it was telling the truth afterwards. Poor old Patricia Whitehead was freed yesterday by the Court of Appeal after spending a salutary weekend in Holloway for lying to the police over what, everyone agreed, was a fairly trivial motoring accident. The problem was that, a week after perpetrating the deceit, Mr and Mrs Whitehead - a Sunday school teacher and a cub scout mistress respectively - then went back to the police to own up.

Mrs Whitehead did it for the best of motives. "She wanted to support her husband and protect her children," one of her neighbours lamented yesterday as the appeal was in progress. The sad irony was that, in the event, she did neither.

It had all begun when her husband, David, collided with a motorcycle near their home in Brockenhurst, Hampshire. Afraid he would lose his licence under the totting-up procedure, he persuaded her to tell the police that it was she who was driving. "She was distraught," said the neighbour, "but she did it out of loyalty."

It's a funny thing, loyalty. Loyalty to what? EM Forster, you will recall, said something about being faced with a choice between loyalty to one's country and to one's friends and hoping he'd have the guts to choose the latter. But what of loyalty to the truth? Or is that too pious a thought in a society where mendacity is woven into the fabric of daily life? What is truth? And do we nowadays stay for an answer?

A survey of dishonesty in modern Britain was published only last month by the Association of British Insurers. They have a particular interest in the subject, having lost between them, they estimate, some pounds 600m in false or exaggerated claims in 1994. You know the kind of thing - claiming the pounds 150 camera you had nicked cost pounds 500, or trying it on for storm damage when the roof was falling apart in any case. At any rate, they assume you know the kind of thing, for their survey - conducted for some strange reason on cross-Channel ferries - shows that 49.8 per cent of people "know someone" who has committed some form of insurance fraud in the recent past.

But they did not only look at insurance fraud. In the anonymity of the ferry lounges they asked about dishonesty in general. Some 44 per cent of people thought it was OK to make personal phone calls from work; 16 per cent said it was all right not to declare all income tax; 9.7 per cent use public transport without paying; 9.5 per cent would keep a pounds 5 note they saw someone drop but 98 per cent would have scruples about stealing a bar of chocolate.

Perhaps the most revealing finding was that 33 per cent of those committing insurance fraud considered themselves to be totally honest and thought their action was justified because they had previously incurred losses without claiming or because they had paid years of premiums without ever claiming.

There have always been advocates of the fib as a social lubricant. "Most lies are quite successful and human society would be impossible without a great deal of good-natured lying," said Bernard Shaw. He was thinking, no doubt, of the lie as an act of tact. "I rang you back but your line was engaged" is that much nicer than "You figure so little in my thoughts that I forgot all about you". A little inaccuracy sometimes saves tons of explanation, as Saki had it.

Then there are the lies we tell in the hope that we are protecting one another. Parents deceive children in all kinds of ways, from stories about Father Christmas or the Tooth Fairy to more problematic situations in which those who do not lie outright to their offspring resort to evasion. Such paternalism is continued later in life in certain spheres, as with doctors or relatives who decide that patients should be deceived about the seriousness of their condition because the truth might undermine their will to live. The number of occasions when it is right for parents, doctors and others to deceive are few, says Sisela Bok, Harvard professor of ethics, in her book on lying.

Next come the lies we tell to those we feel have no right to ask the question of in the first place. Finance companies that ask those applying for a mortgage whether they have ever had a sexually transmitted disease - now that information on HIV tests is deemed insufficient - probably get short shrift, and with some moral backing: Cardinal Newman, for example, held that it was not wrong to give a misleading answer to a personal question asked without sufficient warrant.

And where is the border between suggestio falsi and suppressio veri when it comes to employment? It may be right for candidates to put their best feet forward in response to questions at a job interview rather than highlighting their weaknesses. But is it wrong for an employer to write a reference for a dud employee that lauds their few good qualities and omits mention of all else?

Nor are those examples that seem self-evidently wrong necessarily so. "There's only two kinds of people on this estate," an inner-city resident once told me, "those who fiddle the electric meter and those who are cold." Benefit fraud may cost the nation pounds 654m (up by 30 per cent over the past two years) but, as St Thomas Aquinas pointed out, those who steal to live do not necessarily sin.

But modern liars plunge increasingly into the eddying waters of a moral relativism in which so often the end is taken to justify the means. So we have frustrated policemen who lie to put villains they know to be guilty behind bars. We have politicians who are "economical with the truth" when, for every one case in which lies are justified (such as in conducting secret talks with Sinn Fein to prepare the way for public peace negotiations) there are 999 where they are not.

For lying often hides a greater dishonesty. Businesses whose staff resort to falsehoods about cheques in the post are often engaged in systematic ruses to defraud creditors of prompt payment. The fear is that all this is on the increase. The insurance survey showed that although one in four people would be happy to exaggerate insurance claims (to cover the amount lost through excess penalties) that figure rose to almost 40 per cent when those under the age of 30 were asked.

As so often, sadly, it is Americans who lead the way in such issues. "Have we gone beyond the bounds of reasonable dishonesty?" asked one frank internal CIA memo during the Westmoreland/CBS libel suit. "There are two kinds of truth: real truth and made-up truth," as Marion Barry, the mayor of Washington, enigmatically said upon his arrest on drugs charges. Or perhaps I have missed something here.