KEY POINTS:
A gaffe is a true statement that outrages the hypocrites, who then mobilise to shut the truth-teller up. The most common gaffes are about politics and religion, because those are the areas where the level of hypocrisy is highest.
Which explains John Kerry's problem, or why Muazzez Ilmiye Cig faced the prospect of going to jail in Turkey last week.
John Kerry inadvertently spoke the truth about why some people end up in the United States armed forces while others do not. Speaking to students in California, he said: "You know, education, if you make the most of it, you study hard ... you can do well. If you don't, you get stuck in Iraq."
Cue mass outrage. How dare Kerry suggest that people might be in the US Army because they lacked the education for softer, safer, better-paying jobs, or indeed might have joined precisely to get that missing education?
No, they're all there solely because they are patriots, and anybody who says differently will be spanked soundly and sent to bed without supper.
Senator Kerry issued a grovelling apology ("I sincerely regret that my words were misinterpreted to wrongly imply anything negative about those in uniform"), and cancelled any further campaigning in support of Democratic Party candidates in the mid-term elections, returning to Washington in order not to be a "distraction". Too late, of course.
The Republicans leaped on Kerry's remark as a golden opportunity to paint the Democrats as unpatriotic and disloyal to the armed forces (even though most senior Bush Administration officials, including the President, the Vice-President, and the national security adviser, successfully avoided service in Vietnam). And yet Kerry's remark was entirely true.
Ordinary soldiers are not the "scum of the earth", as Wellington called the British infantry who won a dozen battles against the French for him in Spain, but they are definitely not the creme de la creme in educational terms. Most of them are there because it was their best remaining option.
The Pentagon's own figures show that only 10 per cent of American enlisted troops have any post-secondary education, whereas 56 per cent of the general population does.
It has been true since Sargon of Akkad created the world's first regular army over 4000 years ago: it's mostly poor people who join the army, because rich people have better options.
The military themselves recognise this in their recruiting ads, which stress the opportunities for further education during or after military service. It's obvious, but you're not allowed to say it plainly in public.
More admirable than Kerry, because her gaffe was deliberate and she refused to apologise, is Muazzez Ilmiye Cig, a 92-year-old Turkish archaeologist, who said bluntly that hijab - "Islamic" headscarves that hide women's hair - are not Islamic at all but a 5000-year-old Middle Eastern tradition.
The great thing about being 92 - one of the few good things about being 92, apart from not being dead yet - is that you no longer have to care about your career or what people think.
As one of the world's leading experts on Sumer, the first civilisation, Cig published 13 books and dozens of scholarly articles on her subject and earned great respect within that small community.
But then she published a book last year about her own convictions (My Reactions As a Citizen) and all hell broke loose in Turkey.
All she said was that the headscarf, now a badge of Muslim identity for devout women in Turkey and elsewhere, was actually first worn 5000 years ago by temple priestesses in Sumeria whose job was to initiate young people into sex. They were not prostitutes; only the daughters of the rich and influential got temple jobs.
So gradually the wearing of headscarves came to designate "respectable" women; that is to say rich women, not peasants and slaves. The fashion persisted down to Greek and Roman times and was picked up by the Arabs when they conquered Syria in the generation after the Prophet.
Well, I could have told her that. I grew up a Catholic in prelapsarian Newfoundland and the nuns who taught my sisters wore the full Sumerian gear. Until a couple of decades ago Catholic nuns still dressed like any respectable Middle Eastern woman (of any religion) of two or three thousand years ago. Cig was just stating the obvious historical truth. A serious gaffe.
She is not an innocent abroad. She has been an activist in feminist causes since the 1930s, and she recently wrote an open letter to Emine Erdogan, the Turkish Prime Minister's wife, urging her not to wear a headscarf in public.
"She can wear whatever she likes at home, but as the wife of the Prime Minister, she cannot wear a cross or the headscarf," Cig told Vatan, a popular daily newspaper.
So Islamist lawyers brought charges against her for "inciting hatred and enmity among the people," and she ended up in court facing the prospect of one and a half years in prison.
But 25 lawyers showed up to defend her and the state prosecutor himself asked the judge to drop the charges. In half an hour she walked out of the court a free woman, cheered by the crowd that had come to support her.
The hypocrites do not always win.
* Gwynne Dyer is a London-based independent journalist.