This weekend, I'm speaking at an event about conspiracy theories at Conway Hall. There are still millions of people who believe, despite overwhelming evidence to the contrary, that 9/11 was an 'inside job', committed by the US government to justify imperialist expansionism.

You have probably met one of these 'Truthers' at one point or another. I've met several. Last year, I released a paper about the dangers of conspiracy theories called The Power of Unreason. Within hours, the online conspiracy community launched a campaign to discredit the work. On hundreds of conspiracsts blogs, the paper was presented in an exaggerated, distorted, inaccurate way. Our recommendation to teach critical thinking in schools became 'pushing propaganda on our children'. The key finding that terrorist organizations often use conspiracy theories as part of their propaganda become 'Demos accuses the 9/11 Truth Movement as [sic] being terrorists'.

Then it lurched into the thickets. Unfortunately for us, the Greek letter theta takes the place of the 'o' in the Demos logo. For some of the conspiracy theorists, this was the secret 'eye' of the Illuminati, of which Demos was clearly a part (I've never understood why such a secret organization would have such an overt symbol). As an author, I was accused of being part of the conspiracy itself: at best unknowing, naïve and myopic, at worst a disinformation specialist or government agent openly supporting state-terrorism.

It is of course important that citizens do not take the word of our governments at face value. They often lie and cheat and cover things up. But it is a very selective application of epistemological standards that marks the 9/11 Truthers. When critiquing 'official' stories, they demand impossibly exacting standards of verification - every minor anomaly is a smoking gun. Simultaneously, they will accept the most implausible set of absurdities and logicial fallacies, if it helps weave a counter-narrative.

Some Truthers will be attending this weekend's event, and there is what one might consider a conspiracy theorist speaking on the panel. It should be interesting and possibly heated, especially if any of them think I work for Mossad. But I think the high watermark of the 9-11 Truth Movement has passed. Most of their claims have been debunked, and I sense the movement is losing momentum. But there does remain a foul smelling legacy. In some communities of young people I've worked in, a vague, ill-informed conspiratorial view of the world is almost omnipresent - that the US/UK/Israeli government committed the 9/11 attacks is almost a truism. The Truthers are partly responsible for that. When reasonable skepticism tips into unthinking, blanket cynicism it can drag people into a cul-de-sac of pointless despair and helplessness, where nothing can ever change because mighty powers are ranged against you. The worst bit is that time and energy that could be spent looking into real conspiracies - and there are plenty of them - is sucked into a black hole of nonsense, and utterly wasted.

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