Anyone else nostalgic for a time when we didn’t know the names of the nation’s chief health officers? Or when it would have been slightly ludicrous to declare, as a friend of mine did the other day, that they had a “favourite epidemiologist” among the bevy who are regularly on television?
Marylouise McLaws was my friend’s favourite. Catherine Bennett, on the other hand, was regarded as too willing to take risks.
Given that neither my friend nor I have any scientific qualifications, how do we make these judgments? Some combination of gut, assessment of track record, and entirely subjective preference, I guess. Hardly scientific.
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More importantly, how are we to make sense of things when the experts disagree? For example, on the efficacy of masks, the speed and tightness of lockdowns and the percentage of people who will have to be vaccinated before we can “open up”?
“Trust the science” is the mantra of the times. Greta Thunberg says she doesn’t want us to listen to her on climate change, but to the scientists.
In the pandemic, every state premier insists they are following the advice of their CHO – although, if that is the case, there is a readily apparent difference in approach of Victoria’s Brett Sutton and NSW’s Kerry Chant.
Every politician says they are following medical advice – even when, as in the case of the prime minister, they are apparently also making “representations” to the advisers.
We have been educated to think that science is a matter of logic and certainty but, as we see daily, scientists can disagree, politics intervenes, and scientific understandings can change.
So what is science?
I have been using some of my locked down hours to trawl through the text books I studied 40 years ago during an undergraduate course in the philosophy of science. It has been humbling and bolstering.
It was the Enlightenment philosopher David Hume who first pointed out that when we make assumptions about the world based on our experience, we are not behaving rationally.
The classic example used to illustrate what Hume called the problem of induction is swans. For years, all swans were white (at least for Europeans). Most people would have assumed this was a natural law, part of the immutable nature of things. Then they travelled to Australia, and found black swans.
Hume concluded that it was impossible to draw any general laws on the basis of past experience and irrational to make predictions about the future based on the assumption it will resemble the past.
And yet, we do. We all do. It is human to make such assumptions.
Twentieth century philosopher Karl Popper claimed to have solved the problem of induction, and to have rescued human beings’ claim to be rational creatures.
Popper recast our understanding of what it is that scientists do. Far from trying to prove their theories true, he said, they were trying to falsify them.
Hypotheses might come from observation. They might come in a dream. It didn’t matter, said Popper. The key was to have a “bold conjecture” to test it against reality and abandon it and construct another if it didn’t match the observable facts.
This was the progress of scientific knowledge, said Popper. Not a matter of certainty or absolute truth, but of what “worked” in the real world.
Popper famously wrote: “Science does not rest upon solid bedrock. The bold structure of its theories rises, as it were, above a swamp. It is like a building erected on piles. The piles are driven down from above into the swamp, but not down to any natural or ‘given’ base; and if we stop driving the piles deeper, it is not because we have reached firm ground. We simply stop when we are satisfied that the piles are firm enough to carry the structure, at least for the time being.”
In other words – and I think this is a key insight – you can be rational without being certain.
But there is a problem. Philosopher and historian Thomas Kuhn explored how scientists actually behaved, and found that they did not meet Popper’s ideal of rational behaviour. They clung to their theories long after anomalies and problems had emerged.
The knowledge that disease was spread through germs was resisted for decades, despite the evidence.
The ancients believed that all celestial objects revolved around the earth in circular orbits. When it became clear that this theory did not explain all the observations of the night sky, astronomers produced ever more complex charts to try to fit the heavens to their beliefs.
Kuhn concluded that science is broken up into three distinct stages. First, there is mere observation – pre-science, with no theory or paradigm. Then comes “normal science” which proceeds within an accepted theory, with knowledge within that framework being gradually enlarged.
Eventually, problems emerge – phenomenon that don’t fit the theory. Usually, these will at first be dismissed as mistakes on the part of the researchers. Gradually the tensions increase to a point of crisis. Then, there will be revolutionary science, and a new theory will replace the old.
This is the “paradigm shift” – a term that entered the language thanks to Kuhn’s work.
There has been a paradigm shift during the Covid-19 epidemic, around the issue of airborne transmission of the virus.
At first, scientists believed the virus was spread on surfaces and through droplets, which fell quickly to the ground. Months of evidence suggesting airborne transmission accumulated before the Centre for Disease Control and the World Health Organisation belatedly accepted, only a few months ago, that it was a primary means of contagion.
Had the evidence, which went against the previously accepted paradigm, been accepted faster we would have been wearing masks earlier and worrying less about deep cleaning and more about ventilation.
Kuhn concluded that the notion of scientific truth, at any given moment, cannot be established solely by objective criteria, but rather by a consensus of a scientific community.
That isn’t a bad thing. “Normal” science works most of the time.
Scientists know that theories are often revised or even replaced as a normal part of the scientific process.
But the public, encouraged to think of science as a matter of certainty, may consider these changes a lack of authority or expertise.
Add to all that the fact that science is done by fallible human beings, who vary in experience, expertise and rigor, and we begin to understand why they can – even must – disagree.
In the case of this pandemic, the science necessarily interacts with deep-rooted, perhaps barely examined political beliefs about the nature of government, and the necessary limits of freedom.
How do the respective CHOs, for example, interact with Gladys Berejiklian’s libertarianism in the case of Kerry Chant, or Daniel Andrews’ authoritarianism, in the case of Brett Sutton?
These people are human. The conversations must be two-way, and so must the flow of influence and understanding of what is possible.
Add to all that human fallibility – the ego in clinging too long to a theory or a world view that doesn’t fit the evidence, or doesn’t work.
None of this is to suggest that the “listen to the science” mantra is wrong. Exactly the reverse.
Science remains a vital method of understanding the world, and the only means of making robust predictions about it, and rationally adapting our own behaviour as a result.
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This is how we divide the scientists from the ideologues.
But science is a human phenomenon, not some ideal, crystalline source of certainty.
Translating this to our present dreary, locked down situation, the evidence suggests that lockdowns work, governments need to govern, vaccines also work and libertarianism is not suited to the times.
As for the big, almost existential questions – will life ever be the same again? How many of us must be vaccinated before we can “open up” and what does that mean? Will there be a time when I don’t know the names of any epidemiologists?
We are still driving those piles into the swamp.
We don’t have to be certain in order to be rational.
Rather, the burden of rationality, particularly in times such as these, is that certainty is a luxury not available.