I guess this is a response to the claim I sometimes read that “We choose our beliefs”. I think there’s some truth in that, but would supplement it: “We choose our beliefs… but the universe pushes back”.
What do I mean by that? Perhaps an analogy that I owe to Ernst von Glasersfeld will be helpful. He describes our experience of the universe as like being blind-folded in a pitch black forest and having to find our way out. We can’t see a thing, and some paths are blocked by tree trunks, deadfalls, cliffs, rivers and so on. We can feel a way out by touch, but it’s not the only possible way: there are others, perhaps many others. Some of them will be shorter and better than the one we found, so it’s worthwhile to keep exploring.
He suggests that we don’t have direct access to the universe itself to observe and measure it. Our access is always mediated by our assumptions and by the limitations of our senses. He’s an ‘instrumentalist’, in philosophical terms: our theories are not the truth about reality, they’re just useful for our purposes.
So a concept like the ‘quark’, which we can’t see directly but must infer from experiments, is not seen as ‘real’, but as a concept that is helpful for explaining the behaviour of subatomic particles. But something we can see, like light – the thing we use to see – is also understood as a concept, rather than reality itself.
Some people – who usually have some form of motivated reasoning going on, either in terms of selling something or persuading others to an ideology – tend to take that and say “No-one has direct access to reality, so anyone’s beliefs are as good as anyone else’s, and no-one can be told they’re wrong”. Doesn’t matter whether it’s anti-vax, climate change denial or recent creationism, these philosophical ideas tend to be abused to suggest there is no meaningful difference between different knowledge claims.
This is where the notion that “the universe pushes back” becomes important. Because it does. No matter what your beliefs, if you step off a tall building, you will plummet toward the ground. No belief system will change that. If you don’t get your kids vaccinated, and they’re exposed to the disease, they (very likely – it’s more probabilistic than gravity) will get the disease. If you pump vast quantities of carbon dioxide and methane into the atmosphere while cutting down forests, the global climate will warm.
When finding our way out of that forest, it’s pretty easy to slam into a tree really hard.
We can certainly have an argument about realism vs instrumentalism. I kinda doubt we’ll solve it, since philosophers have been debating it for decades. But either way, really: the universe pushes back.