Since time immemorial a good proportion of humankind has found pleasure in sucking smoke into their lungs and exhaling a long, relaxing, deliberative breath. Another good proportion of humankind has called it a disgusting habit.
Until quite recently the two sides in this cultural conflict were fairly evenly balanced. Smokers probably had a majority at times. Non-smokers had to suffer their rituals and fumes and smokers had only to suffer our distaste.
But once smoking became conclusively linked with lung cancer the tide turned. Armed with health information, non-smokers took the moral high ground and used their new weapon not just to draw numbers from the other side but to persecute remaining smokers with a righteous savagery unseen in the war before.
Smokers were chased from restaurants and bars, workplaces, public halls and everywhere decent people gathered. They were pursued from the front steps of office buildings to the back alleys and forced to huddle together in recesses where nobody else need breathe their air.
On top of these indignities, their tobacco was taxed at punitive rates, rising by 10 per cent annually, to the point that smokers' families suffered increasing hardship and cigarettes made dairies a target of armed robbery.
And all of this was small fire compared to the heavy artillery brought to bear on the business of marketing tobacco products.
If it seemed that something more than health must be motivating this crusade, something cultural, that suspicion has been strengthened by the way the anti-smoking campaign has been divided over the invention of "vaping".
This week the Herald revealed a number of principals of high-decile secondary schools have added their names to an open letter organized by Ash, urging the Government to regulate the sale of vaping products much like those for smoking.
It's a year since Associate Health Minister Jenny Salesa promised to introduce legislation along those lines. Obviously the problem for the Ministry of Health is that vaping is not much like smoking as far as health is concerned. The one thing they have in common is nicotine.
Nicotine is not the carcinogen in cigarettes. That fact should be written in capitals every time vaping is reported. Usually it's not even mentioned. People are still surprised to learn the killer in tobacco smoke is not the nicotine but the tar and other gunk it leaves in the lungs.
As Ash chair Professor Robert Beaglehole concedes, "Vaping is the inhalation of nicotine dissolved in liquid, often with flavours. You get the nicotine but you don't get the deadly constituents of burnt tobacco."
Vaping is deadly if it lets oil into the lungs, which is how it caused the deaths in the United States recently, but vaping products properly made are not lethal, which cannot be said for tobacco.
So why regulate the marketing and display of vaping products as if it was as harmful as smoking? Beaglehole said, "We desperately need legislation and then regulation to encourage people who want to stop (smoking) to vape, but discourages non-smoking young people from vaping."
That's a tall order. How would suppliers know whether a customer was a former smoker? But again, why restrict vaping to them?
The only conceivable justification for regulating vaping on health grounds would be to prevent young people becoming addicted to nicotine and moving on to tobacco. But Beaglehole says there's only a "slight risk" of addiction from vaping and Professor Doug Sellman of the National Addiction Centre agrees the risk was "very small".
Nevertheless, Sellman would restrict sales of vaping products to pharmacies. "We shouldn't have vaping shops," he said, "We should see it as a medicine, not as a recreational product."
The weakness of their case suggests to me these public health professors are really moved by a dislike of business and a cultural aversion to any pleasure that resembles smoking. Even cigarette lollies have disappeared.
It is significant that most of the 36 school principals signing Ash's open letter are from high decile schools. Those heading lower decile schools probably have worse things to worry about, including smoking.
In fact, given the persistence of smoking in lower-income communities and the propensity of all teenagers to have a furtive taste of tobacco, principals in lower decile schools might consider it progress if half of their students were vaping instead.
Smoking is cultural. Watch the way workmen all hold their roll-your-owns the same way and draw on them the same way in their "smoko" breaks and tell me it's not cultural. Don't tell me they haven't heard the health warnings yet. Don't insult their intelligence.
Non-smoking is cultural too. The principals of well-to-do schools find any practice resembling smoking to be not very nice, not the way they want their students to be. I agree but the law needs to be fair.