Life is short, so we need to prioritize the things we spend our time and brain power on. It would be nice to think we could take every proposition the world confronts us with, think about it, research it, and come to a conclusion about it (even incorrect conclusions take a certain amount of work to come to). This would be naive though; there’s too many. So if we want to make a difference anywhere, then we need to dismiss some things without thinking about them.
Sometimes this is dangerously easy, and you might end up dismissing a point of view because, say, it is expressed to you by someone you dislike. Other times, it can be difficult to dismiss something.
You might be surprised at how difficult it can be to prove a conspiracy theorist wrong. Confronted by one, the best thing to do for your peace of mind is to walk away and try to avoid thinking about them. This is hard to do though - they can be so zealous and so wrong in so many ways, which is appealing. When it comes to any other issue, zeal and wrongness are a recipe for a fun conversation. Someone says something you believe to be wrong, you challenge them. The hope is that the conversation ends with someone changing their mind. But even if this doesn’t happen, it can still be productive. You might learn some historical fact or statistic you’d not heard before, you might encounter a creative line of reasoning. At worst, you might at least learn something about the person you are talking to, or someone will say something entertaining. The probability of all these nice things happening is increased if the speakers are strongly invested in the subject.
Not so with conspiracy theorists. A moment spent talking to them is always a moment lost. You may think it will be easy to convince them they are wrong (it can’t be that hard to demonstrate that banks are not controlled by Jews, can it?). But horrifyingly, you will be talking about a subject in which, weirdly, they are kind of an expert. It sounds strange, but creationists may be better armed for a debate about evolution than you - unless you have either a degree in biology or a means of accessing wikipedia.
It is theoretically possible to change their mind. But they'll have arguments to present you with. Their arguments will be rubbish, but on each one you'll have to do a smidge of grudging research, a paragraph of explanation why “no, it wouldn't really be that much of a coincidence.” You’ll have to at least take a long look down the rabbit hole that they have fallen, and there’s some shit down there man, like real shit. But what if they have books? What if they have a perspective that seems to have been superficially developed over several decades?
(I’m using conspiracy theorists as an extreme to illustrate something here. There are other points of view that are not conspiracies that follow the same lines. I had a lot of experience of the Shakespeare Authorship Problem - that “debate” is a load of rubbish, but the problem is that it does a very good job of masquerading as a serious scholarly issue)
So we need to walk away. But when we do this, can we still call ourselves thoughtful people? If you were talking about a real issue, to do this would reflect badly on you. The people you were arguing with will tell you you are afraid of the truth. We need a rigorous way of dismissing things.
In the case of conspiracy theorists, there is a vicious circle they go through. So let’s say that we believe that a group of powerful people has conspired to make us believe something. What happens now is that any argument against our proposition can be said to be part of the conspiracy. This creates a bubble around us that turns reasonable arguments against our beliefs into food for our paranoia. This encourages obsession, moving us to read (and, regrettably, write) little outside the subject of our pet conspiracy theory. Isolated, our theory can become as tangled as it likes, making it harder for an objective voice to come into it and bring a voice of reason.
It makes sense to ignore a person that seems to have succumbed to this. It is a destructive instinct that is capable of generating sincerely held beliefs out of nothing. It is interesting to compare it to the distortion that happens due to vested interests. When an oil baron tells you that global warming is a scam or when a person with a hard drive full of pirated films tells you that copyright is bad for society, you know it isn’t worth talking to them* - that’s another category of people that should be dismissed. The difference is that the instinct I’ve outlined generates sincere beliefs while the oil baron, if they truly care about the issue at all, is more likely to doubt themselves.
The rule I see myself following is “do not ascribe to reason a belief that can be more easily attributed to a human instinct”. When I look at it on the page like that, it seems pretty damn lazy. But if we're careful about what those instincts are, we can watch out for them within ourselves.
I’ve seen people attribute truly ridiculous things to Shakespeare’s plays - trying to work out his life’s history through amateur cryptography and the most tenuous literary analysis you can imagine. Why? Because it’s fun to attribute meaning to any image you can find, and it is fun to get to know a person. These are the two instincts on which I blame the all the ridiculous study of the Shakespeare Authorship Problem.
There is somewhere else that I see these instincts pop up - the field of dream analysis, which is large but shrinking. When ever I have a conversation about someone’s dream, I don’t allow myself to think of it symbolically and I warn others against doing so. It also helps that I’m backed up by recent findings in psychology.
*copyright is bad for society, but still.