Guest post by Michael Slezak

Tim Blair’s most recent attack on reason came in the form of a post that argues that we shouldn’t appeal to scientific consensus when devising policy. Behind Blair’s rhetoric is a very common argument that, while faulty, is surprisingly powerful. Debunking it is worthwhile, especially when this faulty logic is used to justify doing nothing about climate change.

Blair lists a bunch of things that have been mislabeled as science (like Marx’s social theory) and a bunch of things that scientists have said that have been proven to be wrong. In each of these cases, the arguments that relied on the so-called “science” were bad. Blair concludes that appealing to science, in general, is therefore a rhetorical trick that ought to be avoided.

Science is a powerful word, now more so than ever, which is why it’s so often invoked by non-scientists (Engels, Kevin Rudd, Al Gore, Malcolm Turnbull, Penny Wong, angry emailers) seeking authority. Mention “science” and you’ve won. Which might explain Penny Wong’s recent comment on The 7.30 Report:

“I looked to where the weight of the science is, where the consensus science is, and I look to the fact that our own scientific institutions in Australia, the CSIRO, the Bureau of Meteorology, the international scientific community.”

How could one dare oppose someone so awesome that they can cite science four times in a single sentence, even if that sentence is scientifically short on verbs in relation to nouns?

As a champion of science and evidence-based policy, you might be surprised to hear me agree with two of Blair’s supposedly anti-science premises.

  1. Our current scientific theories are almost certainly wrong.
  2. You shouldn’t believe scientists.

Let me start with the second issue. Blair takes great pleasure in making fun of the supposedly silly things that scientists have said. (He’s running a series of posts about it.) Among the list are scientists saying quirky things that nobody else has ever agreed with as well as the results of studies that were unable to be confirmed.

Blair is exactly right that it would have been a mistake to make policy based on the advice of these quirky scientists or studies that appeared to reveal something that was never confirmed.

Nevertheless, Wong is expressing the right attitude: policy should be based on scientific consensus. Scientific knowledge is not made up of quirky scientists and lone studies, it is made up of broad consensus.

So, while you shouldn’t believe scientists, but you should believe science. And the scientific consensus around climate change is very clear.

Ok, but none of that seems to matter if we accept the other premise above, right? If our current scientific theories are wrong, then why should we make policy based on them?

Firstly, it’s true: our current scientific theories are almost certainly wrong. If you look through history, all of our most successful, most beautiful and most explanatory theories have been wrong. Based on that evidence, we’d be mad to think our current theories are right. Philosophers of science call this argument the Pessimistic Meta-Induction. (Comedian Dara O’Briain makes some funny jokes about misuses of this form of reasoning.)

The question is, what follows from the Pessimistic Meta-Induction? If our theories are false, should we ignore them?

The answer is a clear “No”. If you look through the history of science, successful scientific theories that garnered consensus yielded good advice. Although Newtonian mechanics is wrong, it still yields the right advice for any situation you’re likely to come across.

Newtonian mechanics will tell you that if you want your car to go faster, you should make it less heavy. Just because the theory behind that advice turned out to be wrong, doesn’t mean the advice was wrong.

Similarly, even if climate science turns out to be inaccurate in some way, the advice it is giving us is clear. Cutting emissions is essential for stopping global warming.

So, the two premises I originally agreed to can now be appended:

  1. Our current scientific theories are almost certainly wrong, but you should do what they say anyway.
  2. You shouldn’t believe scientists, you should believe science.

Neither of these two observations about science form a sound basis for arguments against acting according to our best scientific theories. Anyone who tells you otherwise is pushing a dangerous agenda.

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