Monday, October 22, 2007

Consensus is a political concept, not a scientific one

In an October 9 essay, Financial Times columnist John Kay wrote about why it can be foolish to allow scientific "consensus" to drive policymaking. Here are some excerpts:
Consensus finds a way through conflicting opinions and interests. Consensus is achieved when the outcome of discussion leaves everyone feeling they have been given enough of what they want. The processes of proper science could hardly be more different. The accomplished politician is a negotiator, a conciliator, finding agreement where none seemed to exist. The accomplished scientist is an original, an extremist, disrupting established patterns of thought. Good science involves perpetual, open debate, in which every objection is aired and dissents are sharpened and clarified, not smoothed over.

Often the argument will continue for ever, and should, because the objective of science is not agreement on a course of action, but the pursuit of truth. Occasionally that pursuit seems to have been successful and the matter is resolved, not by consensus, but by the exhaustion of opposition. We do not say that there is a consensus over the second law of thermodynamics, a consensus that Paris is south of London or that two and two are four. We say that these are the way things are.

[...]Science is a matter of evidence, not what a majority of scientists think.

[...] [T]o use the achievements of science to assert the authority of scientists undermines that very process of science. When consumers believe that genetically modified foods are unsafe, mothers intuit that their children’s autism is caused by the MMR vaccine and politicians assert that HIV/Aids is a first world conspiracy, the answer that the scientific consensus is otherwise does not convince – nor should it. Such claims are mistaken because there is no evidence for them, not because scientists take a different view: scientists should influence policy by explaining facts and arguments, not by parading their doctorates.
Hear, hear.

(Via: Junkfood Science)