Galileo Strikes Again!

Link: I write further on this topic in a subsequent post.

Some interesting comments over at Respectful Insolence got me thinking about the "Galileo Gambit". This is when people with unpopular ideas compare themselves to Galileo with the implication that, like him, they're being persecuted for their unorthodox views but that they will eventually be proved right. Everyone wants to be the underdog, and the Gambit has become such a cliché that several writers are famous for denouncing it. Michael Shermer gave us the snappy aphorism -

Heresy does not equal correctness.

While Carl Sagan went for the comedy angle -

The fact that some geniuses were laughed at does not imply that all who are laughed at are geniuses. They laughed at Columbus, they laughed at Fulton, they laughed at the Wright brothers. But they also laughed at Bozo the Clown.

And so on. In fact, pointing out that not everyone with weird ideas is Galileo, seems to be almost as popular as claiming to be his spiritual heir. Hmm.

Some people don't like this, such as this HIV/AIDS denier who takes issue with those who accuse others of using the Gambit. He's right (about this, not about AIDS) - Shermer and Sagan are attacking straw men, if you take their words literally, because no-one ever claims that just because their ideas are unorthodox, this makes them right. People generally invoke Galileo either as a rhetorical device - to give themselves a cool sense of rebelliousness - or as a defence against the "Argument from Consensus", which says that we should believe something just because most scientists do.

I'm now going to argue that if most scientists believe something you probably should believe it, just because scientists say so. I'm aware that this is an unorthodox view (oh, the irony.) After all, the motto of the Royal Society is Nullius in Verba - "Take nobody's word for it". The oldest scientific society in the world doesn't want you to take their word for anything! I think they're wrong, but the idea that we should "think for ourselves" is fundamental to the way that we in the West argue and think. Once, "heretic" was a serious accusation, now, "not a heretic" is almost as bad. If there's one thing everyone agrees on, it's that everyone should be an indepedent thinker.

But if you take this even vaguely literally, it's obviously bollocks. You take someone's word for it whenever you read a newspaper. Scientists do so whenever they read a journal article - they trust that the results presented weren't made up. "Heretical" science is no exception - if you believe that the MMR vaccine causes autism, it's because you take Dr. Andrew Wakefield's word for it that he did some experiments and got certain results. This is fairly trivial, and you might object that even if we decide to trust the published evidence, we should still insist on evaluating it and interpreting it for ourselves. The idea that anyone can look at the evidence and reach their own conclusion seems only fair and democratic. Just because, say, almost all climate scientists think that the evidence implicates human activities in global warming, this doesn't make it so!

Yet again, it's balls. Unless you are a professional climate scientist (or whatever), or an amateur with an unhealthy amount of spare time, the chances are that you just don't know enough to come to an informed conclusion. Galileo could prove his points by getting people to look down a telescope, but modern science has grown so large and complex that you now need to read and digest dozens of papers to even understand most controversies. Even with life-or-death stuff like the question of whether antidepressants cause suicides, I'd bet that there are only a few dozen people in the world who know all of the relevant evidence. (I say this as someone who knows people whom you would expect to know it, and they don't.)

Ultimately, most of us just can't have an informed opinion about complex issues like evolution, climate change, vaccine safety, or the roots of the economic crisis. Life's too short, and 21st century knowledge is just too much for our brains to handle. It's easy to pick up a few statistics and a couple of stock phrases and think you're informed, but the chances are, you're unskilled and unaware of it. The most rational thing to do, therefore, would be to be agnostic about such matters. This is hard though, so as a second best, we should accept the experts' consensus. Academics are generally pretty intelligent, and if thousands of intelligent people freely discuss something and reach a certain conclusion, that in itself is evidence (although not proof) that what they conclude is true.

So: In theory, we should take no-one's word for it. Ideally, we should gather all the evidence about everything ourselves, and then draw our own conclusions. No-one would deny that this is the ideal, but equally, no-one can deny that this is not actually going to happen. Unless you're an expert on a topic, you have to take someone's word for it if you want to know anything about it. You are taking people's words for it right now. You might as well take the word of the majority of experts.

[BPSDB]