Trusting in our current theoriesPosted: December 10, 2012
Have you ever read one of your old blog posts or journal entries that you wrote when you were a kid, and cringed in embarrassment and horror at how stupid your post was? I have, and from what I know, it’s quite a common phenomenon, especially amongst those that read and write a lot.
I remember reading my old blog written when I was 14, and it felt particularly embarrassing. It felt incredibly pretentious and needlessly philosophical, a bunch of incredibly obvious epistemological mistakes were made; and as a result, I asked myself; wouldn’t I regret writing this blog when I’m 30 or 40 years old as well? I probably would. Hell, I feel slightly embarrassed reading most of the stuff I posted merely a year ago, nevermind a decade ago. Two years ago, I genuinely believed that I was good at writing, only realizing recently that I have a lot to improve on.
But I’ve decided to keep on writing anyway, even if I’m making a lot of foolish mistakes. Even if the probability of me regretting this is high.
It’s essentially the same problem as the reputability of science. Most of the scientific theories in the past about how the world worked was wrong, and the most intelligent people in the past were wrong about pretty much everything. They were wrong about reality, wrong about science, wrong about quantum mechanics, chemistry, philosophy, physics, wrong about politics, about the universe itself. That’s why some argue that because science has been wrong pretty often in the past, current scientific theories are probably wrong as well, even if we can’t explicitly reason why they are so.
How can science be trusted after it’s been proven wrong so many times?
How can I be trusted after I’ve obviously been wrong so many times?
The answer is that hard Bayesian evidence is a lot stronger than weak Frequentist evidence. So most of my theories about the world, and the world’s theories about the universe were wrong. Therefore using Frequentist inference, it’s true that current theories are likely to be wrong as well. But reasoning can provide a much better answer than mere correlational evidence can.
Consider for example, a turkey on a farm. For the first thousand days of its life, the farmer has given it food, and treated it exceptionally kindly. The turkey has been warned that it was in danger, for the farmer has expressed several times that for next thanksgiving, turkey will be eaten. But the Turkey disagrees, claiming that it has extrapolated those one thousand days of kindness, and therefore it has come to the conclusion that it will never be slaughtered. The Turkey is then slaughtered next thanksgiving.
Science is the same. Although correlational evidence is still evidence, it is considered a “weak” form of evidence as compared to logical reasoning from experimental data. So long as we cannot use reasoning to explain how exactly it is wrong, the probability of it being correct is still much higher than wrong.
We should trust in our current theories, because to trust in anything else would be to privilege the hypothesis, a logical fallacy. Right now, our theories are the one best guess amongst all possible ones, the explanation with the highest possibility. To discard the highest possibility answer for no answer at all is akin to saying a 70% chance of achieving something is not good enough, therefore we should switch to a method with a 0% chance of achieving something.
I should trust in my current beliefs, because if I discard them in fear of being wrong, then I will definitely not get it right. Only when I have been presented evidence that my beliefs are wrong, and evaluated them rationally to find them to be true, should I discard my beliefs, and replace them with a belief with a higher likelihood ratio.
Finally, we should trust in science because it is progressive, rather than random. Science is not so much flipping a coin to obtain a theory as it is using old theories to climb to better ones. Even wrong theories have uses — they are the stepping stones from which newer and more correct theories emerges. Just as quantum mechanics have been inspired from Newtonian mechanics, germ theory inspired from miasma, and chemistry from alchemy, it cannot be said that Newtonian mechanics and miasma should never have been invented, for that would imply that Quantum Mechanics and germ theory could never exist in the first place.
I should therefore also trust my current theories, because personal philosophical growth is not a random process. In order to obtain a worldview that better reflects the universe, it is necessary to stick my ideas on the chopping board. If that means being humiliated and having my weak epistemology exposed, all the better.