The truth hurts - and sometimes it hurts those who tell it more than those who hear it.
Nothing illustrates this better than the tale of the giant American tobacco company, Philip Morris, which over the summer was reduced to an apologetic wreck after telling one truth too many about smoking.
A company affiliate made a report to the Czech government about smoking, pointing out the exchequer saved£147m in 1997 as a result of tobacco consumption.
Those who died prematurely, due to tobacco, consequently consumed fewer health and housing benefits than longerliving non-smoking Czechs.
The result was not reasoned debate but an hysterical tide of articles across the western world.
From its New York headquarters, Philip Morris issued an apology which set new standards in the art of grovelling, referring to the company's 'terrible judgement as well as a complete and unacceptable disregard of basic human rights'. It even cast doubt on the report's accuracy, referring to 'purported' cost savings.
In war, the first casualty has always been truth, and the fight against tobacco is indeed a war.
But am I the only one to find the public sacrifice of self-evident truths on the altar of political correctness offensive?
No doubt many in the NHS rejoiced at Philip Morris's discomfiture, and piously ignored that each year British smokers pay£10bn in taxes above and beyond those paid by non-smokers - a hard, indisputable fact compared to the more debatable 'statistic' that smoking-related illnesses cost the NHS£1bn or, depending on the source,£2bn annually.
Mindless zealotry is not confined to smoking. PC-ism spreads its suffocating blanket over every fashionable issue, stifling real analysis and distorting priorities across a range of 'sensitive' issues such as race, gender and sexual orientation.
Take AIDS, for example.
Ignorance kills, but why - except for political correctness - was so much effort directed towards the population at large rather than the two groups, homosexual men and intravenous drug users, who for the first two decades were the primary reservoir of British AIDS?
And why, when HIV acquired through heterosexual contact is rapidly on the increase, is it so difficult to establish one simple statistic: how much greater is the chance of a woman being infected by an HIV-positive man compared with a man being infected by an HIV-positive woman? Though one may suspect that a woman stands a substantially greater chance of acquiring HIV from an infected man, it seems impossible to discover the facts.
The answer, surely, is a collective unconscious desire not to see unpalatable truths when they conflict with fashionable ideas. It is unfashionable to say tobacco consumption might be good for society even if it is bad for the individual, and it is fashionable to believe everyone is the same when patently they are not.
Such woolly thinking is bad, not just because self-deception is the ultimate dishonesty but, more importantly, because in healthcare it prevents the most effective application of public funds.
Addiction to medical fashion has a long history. It runs from Dr Thomas Graham's 'celestial electric bed' for childless couples in the 1780s, through to colon removal for the non-existent disease of auto-intoxication in the early 19th century and today's epidemics of tonsillectomies, hysterectomies, grommet fittings and caesarean births.
It is all very well establishing a National Institute for Clinical Excellence, but is its brief wide enough? It is not enough to identify folly - we must tackle the causes of folly.
Perhaps as a counterpoint to its nanny-knows-best PC culture, the NHS would benefit from local community anti-health councils, which could be play devil's advocate.Membership would be open only to bona fide tobaccosmoking, beer-drinking sceptics with a penchant for challenging every fashionable assertion made by NHS personnel.
Maybe that is going too far. I can't see the secretary of state going along with the idea of gangs of middle-aged lager louts with a dangerous interest in practical teleology having a constitutional role in running the NHS. Perhaps there are other ways.
To prevent the sin of hubris, Roman generals riding in public triumph had a slave stand behind them whispering, 'you too are mortal'. Perhaps NICE or the National Audit Office might train a cadre of hard-bitten cynics to descend on any part of the NHS threatening to adopt a fashionable cause. These shock troops could hold endless seminars on the nature of subjective versus objective knowledge until the perpetrators flung up their hands in surrender, or produced factual evidence to support their position.
Until then, you can't help feeling passive non-smoking will remain as dangerous to people's minds as smoking is to their bodies.