# The Problem of Vestigial Beliefs

If it’s true that no one ever believes something without a reason, then it should be possible to follow a chain of reasoning leading up to every belief that any given person subscribes to.

Unfortunately our beliefs only start out that way. As time goes by, many of our beliefs end up floating free of support unbeknownst to us. The reasoning changes out from under the belief or it’s forgotten entirely, but the belief still persists. Like the coyote in the cartoons we find ourselves mentally wandering right off a ledge and not falling until we finally look down.

A little algebra is the best way I can think of to illustrate this subtle and sneaky process.

Say you have the following equation needing a solution:

X + Y = Z

And it’s provided for you that X is 36 and Y is 64:

36 + 64 = Z

A quick calculation will reveal that Z is equal to 100. Problem solved.

36 + 64 = 100

Now suppose you find out you were mistaken about X and Y. You were given bad information about their values and must revisit the problem. So you insert the symbols X and Y back into the equation and are left with this:

X + Y = 100

There’s something wrong with this picture. X and Y added together may indeed total 100; we have no reason to doubt this possibility. A lot of numbers add up to 100 and this equation could still be perfectly accurate. But, not knowing X and Y, is it appropriate to have any preconception whatsoever about the value of Z? Or do we need to put the symbol Z back in its place and approach the equation from the very beginning, as if we had never solved it in the past?

The answer of course is that we have to start fresh. The mistake in reasoning is obvious when presented as a simple math problem. But when it comes to real life, everyday conclusion-making, we commit this error all the time.

For example, years ago I was interested in magnet therapy, which has become one of many billion dollar pseudoscientific New Age industries. You can find any number of explanations by proponents for why magnet therapy works, but the explanation that snared me had something to do with magnetic fields interacting with the iron in the blood and forcing the capillaries to gradually organize themselves into more efficient matrices or configurations, leading to better blood flow and thus better health all around. If you haven’t done any study on the matter it sounds vaguely plausible. It has the illusion of scientific authority which makes so many therapies in this vein financially successful.

I learned later that the iron in the body isn’t ferromagnetic — that is, it will be unaffected by magnetic fields, at least in any way that matters in this context. The truth of this becomes blatantly obvious when you consider an MRI exam. The magnetic fields an MRI scanner produces are stronger than any magnet used in magnet therapy by many, many magnitudes. To undergo an MRI you must be screened for anything metallic beforehand because it becomes a projectile when the machine is turned on. If the iron in the body could be at all affected by these therapeutic magnets, an MRI scan would be horrifically fatal.

So for a (mercifully) short time I was actually left with the belief that magnetic therapy works, but not for the reasons I first thought. But why did I retain this conclusion when the solution to my equation depended entirely on the truth of this particular variable? If I’d been presented with the MRI argument at the same time as the magnetic therapy argument, would I ever have had any reason to believe in magnetic therapy in the first place? Why did knowledge of the absence of ferromagnetism not instantly nullify my conclusion upon discovering it?

Our faulty human brains are the answer, and once again it’s something we have to stay vigilant about.

The brain is very susceptible to retaining unsupported beliefs out of habit. Deep cognitive grooves are cut by long-held beliefs that can’t always be filled in overnight. The mere lifespan of the belief has a way of masquerading as additional confirmation and support, in our perception. We can go on for years believing something one day simply because we believed it the day before, and for no other reason.

One of the best ways I can think of to test whether the chain leading to a belief is intact is to forget I believe it. Any given belief should be rediscoverable; if I woke up with with amnesia tomorrow I could still be led back to the belief in a natural, open-ended manner. If I had to learn math all over again I would find that, given X is 36 and Y is 64, Z would still equal 100.

If you discover a new fact that may alter a belief you have about the world, try rebuilding your belief from scratch. Recompile it, so to speak. See where the links in the chain lead. Ask yourself, “Given my current understanding of the world, is this the belief I would come to today if pondering it for the first time?” If your belief is solid and in line with your understanding, you’ll be led to the same place you were before. New information isn’t a threat to a solid belief, and if the belief isn’t solid, what good is it to you?

“What do I believe today?” is the question to ask yourself. Maybe the answer will match what you believed yesterday and maybe it won’t. If you’re genuinely interested in truth, either outcome is a step in a clearer direction.