The voice of science: let’s agree to disagree (Nature)

Sarewitz uses his Nature column to argue against forced or otherwise false consensus in science.

“The very idea that science best expresses its authority through consensus statements is at odds with a vibrant scientific enterprise. … Science would provide better value to politics if it articulated the broadest set of plausible interpretations, options and perspectives, imagined by the best experts, rather than forcing convergence to an allegedly unified voice.”

D. Sarewitz The voice of science: let’s agree to disagree Nature Vol 478 Pg 3, 6 October 2011.

Sarewitz seems to be thinking in terms of issues such as academic freedom and vibrancy. But there are arguably more important aspects. Given any set of experiments or other evidence there will generally be a wide range of credible theories. The choice of a particular theory is not determined by any logic, but such factors as which one was thought of first and by whom, and is easiest to work with in making predictions etc.

In issues like smoking and climate change the problem is that the paucity of data is obvious and different credible theories lead to different policy or action recommendations. Thus no one detailed theory is credible. We need a different way of reasoning, that should at least recognize the range of credible theories and the consequential uncertainty.

I have experience of a different kind of problem: where one has seemingly well established theories but these are suddenly falsified in a crisis (as in the financial crash of 2008). Politicians (and the public, where they are involved) understandably lose confidence in the ‘science’ and can fall back on instincts that may or may not be appropriate. One can try to rebuild a credible theory over-night (literally) from scratch, but this is not recommended. Some scientists have a clear grasp of their subject. They understand that the accepted theory is part science part narrative and are able to help politicians understand the difference. We may need more of these.

Enlightened scientists will seek to encourage debate, e.g. via enlightened journals, but in some fields, as in economics, they may find themselves ‘out in the cold’. We need to make sure that such people have a platform. I think that this goes much broader than the committees Sarewitz is considering.

I also think that many of our contemporary problems are because societies end to suppress uncertainty, being more comfortable with consensus and giving more credence to people who are confident in their subject. This attitude suppresses a consideration of alternatives and turns novelty into shocks, which can have disastrous results. 

Previous work

In a 2001 Nature article Roger Pielke covers much the same ground. But he also says:

“Take for example weather forecasters, who are learning that the value to society of their forecasts is enhanced when decision-makers are provided with predictions in probabilistic rather than categorical fashion and decisions are made in full view of uncertainty.”

 From this and his blog it seems that the uncertainty is merely probabilistic, and differs only in magnitude. But it seems to me that before global warming became significant  weather forecasting and climate modelling seemed probabilistic but that there was an intermediate time-scale (in the UK one or two weeks) which was always more complex and which had different types of uncertainty, as described by Keynes. But this does not detract from the main point of the article.

See also

Popper’s Logic of Scientific Discovery , Roger Pielke’s blog (with a link to his 2001 article in Nature on the same topic).

Dave Marsay


About Dave Marsay
Mathematician with an interest in 'good' reasoning.

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