The National Rifle Association, America's powerful gun-ownership lobbying group, declares in its motto: 'Guns don't kill, people do.' The slogan is naturally designed to persuade supporters of gun control of the errors of their ways and suggest that, in itself, a firearm is a harmless toy.
One wonders how that phrase rings in the ears of the teenagers who were in the hallway of Heath High School in sleepy West Paducah, Kentucky, on Monday morning. A 14-year-old student walked into a prayer meeting and shot eight fellow students with a semi-automatic handgun.
Three died - including one of the boy's friends, according to reports - and five others were badly injured. Next morning, the local paper ran the headline banner 'WHY?'. We do not yet know the answer, and maybe never will.
In Mississippi, a couple of states to the south, a similar tragedy took place in a high school two months ago when a student ran amok also leaving a handful of students lying in pools of blood. In that case, police have pointed to a cultish group among some of the students that had been planning such an attack.
There is, of course, never a single identifiable reason for such surreal acts of violence: whether the Kentucky killer was an atheist who objected to prayer in school, or was merely miffed at getting a C-minus for maths, the only way to rationalise such horror is to label it irrational.
But, whenever such acts occur, they are by far and away the best rebuttal to the NRA's cherished lobbying cry.
It is difficult to imagine how Monday's shooter would have progressed had he entered the school lobby armed instead with the next best weapon to a gun: a knife. Even had he managed to stab his first victim to death, it would not have been long before he was overpowered.
NRA officials who argue that human beings are the problem, rather than the deadly firearms Americans carry with such abandon, are telling one of the most pernicious (and sadly, one of the most popular) of modern lies.
NRA officials should have acted as defence lawyers for the Aum Shinrikyo cult members who gassed commuters to death on the Tokyo underground. 'Your honour,' they might have argued, 'sarin gas doesn't kill, people do'.
The US constitution's Second Amendment vouchsafes the right to bear arms, but when that clause was written 200 years ago guns were not the nation's primary health hazard. In 1997 Americans are nearly as likely to die from a bullet as from a car crash.
The statistics are sobering. There were more than 35,000 gun-related deaths in 1995, a little over half of them suicides. Another 15,835 were homicides: four-fifths of the 20,000 or so murders in the US that year. Add to this some 1,200 accidental gun deaths, and the NRA has some explaining to do.
The US Centres for Disease Control recently produced a report with some eerie relevance to the West Paducah killings. It revealed that nearly three-quarters of all the murders of children in the industrialised world occur in the US - and added that America had the highest of all rates for childhood murder, suicide and gun-related deaths.
For those who wonder how a lawyer's son could have been wandering round school with a semi-automatic gun in the first place, the answer probably lies in one simple statistic: the US has an estimated 200 million firearms in circulation, nearly one per person. Nearly one in every two households owns a gun - and owns it perfectly legally.
That America is the spiritual home of the gun is a truism. But one can detect a certain ill-advised sense of security in the country of late, and it is time it was shattered. The reason Americans are feeling safer stems largely from statistics showing a nationwide drop in violent crime, especially homicides.
Gun control activists can also point to the first moves by any US president to restrict gun sales, when President Bill Clinton banned the sale of a range of AK-47-style automatic weapons and enacted the Brady Bill requiring background checks on all gun buyers.
But the fact that law-abiding citizens have slightly diminished access to guns, while society's insane or criminal elements can still pick and choose from that 200-million-strong stockpile is hardly cause for celebration.
Perhaps the biggest blow to the cause of the NRA and other Second Amendment fanatics would be to shatter the myth that America is intrinsically a more criminal society than others. The overall crime rate in the States is hardly much worse than in Britain, France or even the so-called genteel Scandinavian countries. A Londoner is far more likely to find his house burgled, for example, than a New Yorker.
Yet there is one statistic in which America outperforms virtually every other nation in the world, and that is murder. Despite some recent improvement, the US homicide rate remains 20 times higher than Britain's.
Perhaps a more truthful slogan for the NRA should read: 'People don't always kill, but guns almost always do.' Just look at the boy from West Paducah, Kentucky.