I'm about to go and give a talk at a certain institution (let's just say it's in a capital city, and it's an educational institute, and it was traditionally concerned with the science of the flow of money...) The talk is on the subject of my "second string" research: argumentation for policy making. The main thrust of the talk is that policy making at its best occurs where people of good will engage in meaningful discourse.
Aye but there's the rub - there are plenty of special interest groups and, let's face it, cranky individuals that won't play by the rules: creationists, pseudo-medics and pseudo-scientific racists. And these people can have a hugely detremental effect on the policy making process because it's hard to identify when these individuals have strayed from "misguided" to "dangerous loon". At best, they sap the time and energy of those people who are prepared to stick to the niceties of debate. At worst, their screed sounds convincing to the scientifically inexperienced and bad things happen.
So how do you recognise cranks? Sadly this isn't the area of my expertise (formal argumentation frameworks anyone..?). So I was pleased to run across this post from Denialism Blog. The heuristic still seems to be, in the words of Winston Churchill,
A fanatic is someone who can't change his mind and won't change the subject.
Now if only I could represent that logically.