Fighting water with water

As regular readers of hofflimits will know, I've been watching with amusement the current spat between the purveyors of homeopathy and the recent 10:23 campaign to highlight its barminess (www.1023.org.uk). If any of you are on Twitter, I'd recommend joining in (#ten23) as it can be very fun in small doses, pun intended. However, it does get a bit wearying after a while seeing the level of "debate " it can sink to - Godwin's law doesn't even come into it. Mainly, I think, because both sides are arguing from two totally different definitions of what constitutes evidence, which holds the key not only to the whole debate, but to the very heart of why people are attracted to moonshine theories.

As I have said elsewhere, looking at all the available evidence, homeopathy performs no better than placebo. Already by saying that, I risk incurring the wrath of believers who will cite a number of studies that supposedly do prove its efficacy. Until you discount those studies that are unreliable because of methodological flaws, and then proofs start looking a little thin. So homeopaths will come back with personal testaments of all the people they know who have benefited from homeopathic "treatment" - and here's where we hit the crux of the matter: Sceptics will never win the argument until they debate on the same terms - the battle of PR.

Say I read an account of someone who passionately recounts the wonderful effect a homeopathic treatment has had on his life. It's an anecdote - file it. But supposing you were to read a book of 100 such anecdotes, all true and all argued with conviction. By the time you get to number 76, many people would be wilting under the pressure of such "evidence". The human brain is hardwired to be fooled by poor risk assessment skills when dealing with large, impersonal numbers in the face of direct experience. Risk of anything is always judged as higher if you know someone who has been personally affected; it's been a useful survival skill, and perfectly reasonable when you consider that for 99% of hominid existence, most individuals would not know more than 30 people.

In their heart of hearts homeopaths know they will never win the argument on scientific grounds, unless the laws of chemistry and physics have changed (and the fact our planet continues to spin would indicate this isn't so). Their best shot is emotional appeal based upon weight of anecdote, something scientists naturally shy away from. But I would argue that half a billion years of human evolution can't be wrong - and one of the biggest parts of the UK economy is testament to this approach: Public Relations. Scientists need to embrace it, to take the argument to the homeopaths.

Returning to my mythical book of 100 Homeopathic Cure Stories, scientists need to come back with a database of 100,000 stories about how a particular drug saved a life. Start with one drug - probably any favoured target of the flat earthers - and bring weight of anecdote to bear on its efficacy argued from an emotional, personal perspective. Keep the evidence handy for those who want to check it, but remember it's not the number of peer-reviewed articles that will count, but the number of names you can cite.

Ridiculous? Probably. Impossible? Well, difficult certainly. But it's not actually the stories or names themselves, it's the act of compilation that will be the story. The world's biggest book that will knock a few placebo tales into a cocked hat. If they rise to the bait, then you've forced them to undermine their own position by dismissing anecdote as being non-scientific. And the science itself leaves them nowhere to go.