We live in a world that is not what it seems.
Before you think that I’ve gone off the deep end and started espousing wacky theories like Manichean-style dualism or the 9/11 Truth movement, let me be clearer about what I’m proposing: I think that we live in a world where purely prima facie beliefs – things we believe because they appear to be so “at face value” – are not inherently reasonable to hold.
This might sound fairly controversial at first glance (which makes it delightfully ironic to me), but hear me out. There seem to be many instances where the first examination of something will often be superficial and miss deeper layers of meaning. When I started thinking about this, tons of examples came to mind – so many, in fact, that I will only be able to touch on a few of them in this entry. (I might also have forgotten some; my mind was going rapid-fire when this thought sparked, and that’s the sort of moment when long-term retention goes out the window.)
One way in which prima facie beliefs may be unjustified deals with the correlation-causation fallacy non causa pro causa. A fine contemporary example of this is the debate over autism and vaccines, specifically the preservative (rarely used since 1999) called thimerosal (or thiomersal, if you live across the pond) that is a form of mercury. If you have ever ventured into any part of the blogosphere that covers autism (and I have), you will see members of the “mercury militia,” as they are sometimes caused, who will claim that their child (they are generally parents of autistic children) was doing just fine until they got a booster shot (many times the MMR vaccine is claimed to be the culprit), at which point their child regressed and was labeled autistic. They are so certain of this that no amount of reasoning about the nonexistent link between the two, the fact that thimerosal has decreased while autism rates have continued their upward trend, or the fact that ethylmercury, the form of mercury that thimerosal is, is excreted much faster than its toxic counterpart, methylmercury. (This is of course all in addition to the growing genetic evidence, but genetics has been implicated for several decades now, anyway.)
When you hear one of these parents speak, all the evidence they need is right in front of them: they saw a normal child regress after a vaccine, and that made them blame the vaccine. The reason that this is so entrenched (besides the rhetoric by individuals in the mercury movement) is because the conclusion seems so apparent – the parent will probably even say that they “saw it with their own eyes.” But the answer is not so obvious, and in fact the causation only seems to be so because the age when children start to regress (if they do in fact regress – not all children do) is the same age when they’re getting inoculations for various childhood diseases.
This is the case with a great deal of things that we think to be true, and it seems like it has almost always been such. We thought geocentrism was obvious – “Look, you can see the sun going from east to west, so it must be revolving around the earth!” – for a pre-modern example. Evolution might be another more recent example of this as well.
My point here is not to cast doubt on our human faculties – after all, we did eventually find out the truth below the surface on many of these such issues – but to suggest that some hesitance should be used when claiming beliefs to be prima facie. Even though some things might really be the way they appear to be (I don’t necessarily deny this), it is often the case that they are not, so presuming such seems to be a setup for failure. When we think something is obvious, that should give us pause to reconsider.
This also means that we must be more cautious when asserting ideas or notions to be “self-evident” – what we are getting at here is that we think the ideas so compelling that no one in their right mind would deny them. But of course it is rarely ever true that ideas are so obvious, and so asserting “self-evidence” is just a way of baldly asserting what one does not know.
There are still some things to work out, but I think that there is a reasonable amount of evidence pointing toward this as a useful heuristic. There may be areas where it does not work, but it is at least food for thought.