Pretty much all of us believe in something. We have ideologies or religions or worldviews of some kind through which we filter everything that we see and hear. It’s very easy to then fall into a kind of intellectual trap where we seek information that confirms our biases, and ignore information that doesn’t fit.
For people who care about knowing the actual, unvarnished truth, this is a problem. Some people, like the Rationalists of Less Wrong or the Effective Altruists, tend to be more obsessed with the ideal of objective truth, and following wherever that leads. But, it’s my humble opinion that most of these earnest truthseekers end up being overconfident with what they think they find.
The reality is that any given model of reality, any given theory or ideology, is but a perspective that views the complexity of the universe only from a given angle based on certain principles or assumptions. Reality is exceedingly complicated, and in order to compress that complexity into words we can understand, we must, invariably, filter and focus and emphasize certain things at the expense of others.
Theories of how the world works, tend to have some grains of truth in them. They need to have some connection with reality, or else they won’t have any predictive value, they won’t be adaptive and survive as ideas.
At the same time, theories generally survive because they are mainly adaptive, rather than true. For instance, many religions help people to function pro-socially, by having a God or heavens watching them, essentially allowing people to avoid the temptations of the Ring of Gyges, or doing evil when no one is (apparently) watching.
Regardless of whether or not you believe that such a religion is true, the adaptiveness of convincing people to be honest when no one is around, is a big part of what makes them useful to society, and probably a big reason why they continue to exist in the world.
In reality though, it’s actually impossible to know with certainty that any given theory or model is accurate. We can assign some credence based on our lived experiences, or our trust in the witness of others, but generally, an intellectually honest person is humble about what we can know.
That being said, that doesn’t mean we should abandon truthseeking in favour of solipsism. Some theories are more plausible than others, and often those ones are at the same time more useful because they map the territory better.
To me, it seems important then, to try to do your best to understand various theories, and what elements of them map to reality, and also understand their limitations and blindspots. We should do this rather than whole-cloth accepting or rejecting them. The universe is not black and white. It is many shades of grey, or rather, a symphony of colours that don’t fit the paradigm of black and white or even greyscale thinking. And there are wavelengths of light that we cannot even see.
So, all theories are, at best, incomplete. They provide us with guidance, but should not blind us to the inherent complex realities of the world, and we should always be open to the possibility that our working theory is perhaps somewhat wrong. At least, that’s the theory I’m going with right now.