How To Disagree with an Expert

In matters of science it’s not supposed to matter who you are, how many degrees you have, or even if you have a Nobel prize or not. All that is supposed to really matter are your observations and your reasoning. But in practice, appealing to authority does have its place. It’s simply not reasonable to expect people to be an expert on everything, and so we need heuristics - rules of thumb – to give us an easier way to form beliefs and make decisions when we’re outside of our own expertise. Looking to see what experts believe is a pretty good heuristic.

In many a debate, especially between laypeople, an appeal to authority is invoked as an argument. Generally speaking, the opinion of an expert should carry more weight than the opinion of a layperson, and even someone who can cite a non-expert source, like a newspaper article, at least makes their knowledge more traceable than someone who doesn’t know the source of their information.

Appealing to an authority only carries weight to someone who doesn’t understand the reasoning behind the authority’s belief. If you know and understand the authority’s reasoning, then only that reasoning counts, and their authority no longer carries any weight of its own. Knowing and understanding someone’s argument undermines their authority[1].

Imagine someone you know makes a claim about some scientific idea they read about in a newspaper. You don’t have to take their word for it; you can go read the article yourself and see what it says. Once you’ve read the article that they read, you will have acquired the same knowledge they did, and you will have removed any authority they had obtained by reading it.

Of course, you don’t have to take the journalist who wrote the article at their word either. If you wonder if the journalist has understood the science correctly[2], you can go read the academic paper that they’ve cited and see if the authors of the paper are making the same claims that the journalist does.

You don’t have to take the scientists at their word either. You could look at their data (as long as it’s published) and conduct your own analysis of it. You can read up on the field and learn what they know. Become an expert yourself. Then you can judge if their reasoning is correct, and see if their conclusions are really entailed by their observations.

Finally, you don’t even have to agree with the data. If you suspect they’ve made some methodological flaws, or you think their data is just a fluke, you could conduct your own experiment and try to replicate their results. If you turn out to be right, perhaps you can find strong enough evidence to overturn their findings and you can suggest a new hypothesis. If you do, write up your results and publish them. That’s how science works.

Sometimes people seem to mistake diligent skepticism for a dogmatic refusal to accept new ideas, and these people then wrongly criticize science for arrogantly handing down absolute truths that you’re not allowed to question. In reality, the idea that experts’ ideas should be challenged is actually one of the most important ideas in science, but the way experts’ ideas are challenged is not by waving your hands and shouting that you don’t like their ideas. Experts’ ideas aren’t challenged from a position of ignorance but of knowledge. If you disagree with a scientific paper, that’s fine. That’s encouraged actually. But you should probably understand the relevant science, or at least have actually bothered to read a paper before you start publicly disagreeing with the authors.

Scientists are their own harshest critics by design; that’s part of how scientific ideas are tested: by inviting experts to try to poke holes in them. This inward skepticism is part of science’s epistemic immune system, how it filters out wrong ideas. But the right to reasonably disagree with an expert is something that is earned by learning and understanding why the expert believes what they do.

For those who want more details about why learning someone’s argument undermines their authority, AI researcher Eliezer Yudkowsky has conveniently provided a full probability theoretic argument for this. You don’t have to agree with him; maybe he’s made some mistakes somewhere. If you think so, you are encouraged to criticize any flaws you find in his argument…after having first read and understood his argument, of course.