The Chronicle-Herald
Opinion, Wednesday, January 28, 2004, p. B2
‘Scientific consensus’ far cry from proof

The Moncton Times and Transcript
Opinion, Wednesday, January 28, 2004, p. D7
Flaw in ‘consensus’ claims

Brian Lee Crowley

MICHAEL CRICHTON is a man best known to many of us as a writer of scientific thrillers – like Andromeda Strain or Jurassic Park.

Crichton, however, also passionately observes and thinks about science and its role in our lives. And he is increasingly worried about what science has become – in particular, how it has been perverted for political ends. This was the subject Crichton chose when he gave the prestigious James Michelin lecture this year at the California Institute of Technology.

True science, Crichton reminds us, does not involve commitment to a particular outcome or set of results. It is not about proving global warming or the safety of genetically engineered foods. It is about a commitment to the scientific method for determining what is true and being committed to whatever results that method throws up, regardless of the political palatability of those results. Science is not a popularity contest.

In fact, science has frequently advanced (and humanity progressed) because one scientist saw something that called into question the assumptions of whole fields of scientific inquiry, and that scientist refused to let the disruption and confusion of settled science distract him from the facts.

Galileo is surely the most famous example. There was a wide consensus in the scientific community of his day that the Earth was the centre of the universe. Galileo looked through his telescope and saw that it was not so. But this was an inconvenient discovery for a society based on the belief that man was at the centre of the universe God had created.

In a powerful scene from Bertolt Brecht’s play about Galileo, the astronomer invites his persecutor in the Catholic Church to look through his telescope and see the truth. The cardinal refuses even to look because, to him, truth is revealed in the word of God as interpreted by the Church. The evidence of his senses could only lead him into error and heresy.

Yet because Galileo was willing to test his ideas against the real world, and the results he came up with could be reproduced by anyone who wanted to put their eye to a telescope and look, his discovery prevailed. Error, however, was not prepared simply to roll over and die. It took many years of long struggle for his truth to prevail.

Scientific innovation almost always has to struggle against those with a vested interest in things staying just the way they are. And that can include scientists. If you were at the pinnacle of your profession in 1912, having made a career out of proving that the Earth’s crust is stable, you’d be mighty disapproving of Alfred Wegener’s upstart theory that the continents have been drifting apart for millions of years. If the physics of Isaac Newton were the foundation of your scientific career, Albert Einstein would have appeared to you a dangerous mystic.

Science does not proceed by consensus. On the contrary, science is often the work of individualists and mavericks who are willing to be guided by the evidence they have found, rather than by the preferences and beliefs of political authorities or even their fellow scientists.

Yet the notion of “scientific consensus” is increasingly used to cut off controversy and dissension within the scientific community around politically popular ideas allegedly based in science. There are many arguments to be made for and against the science of global warming, for example, but there are perfectly respectable and reputable scientists on both sides, and the science (in the sense of observable phenomena subject to repeated testing and giving clear results that can be reproduced reliably by other scientists working independently) is clearly not settled.

Yet, much of the scientific community rose up in righteous indignation against a Danish statistician, Bjorn Lomborg, who had the temerity to publish a book looking skeptically at the soundness of many environmental claims, including global warming. As Crichton observes, Lomborg was treated as a heretic, one who questioned sacred beliefs. And the bulk of the criticism was based on Lomborg being outside the “scientific consensus.”

Crichton summed up for me the acute discomfort that the Lomborg case, among many other recent examples, had caused me. “Historically, the claim of consensus has been the first refuge of scoundrels; it is a way to avoid debate by claiming that the matter is already settled…Consensus is invoked only in situations where the science is not solid enough. Nobody says the consensus of scientists agrees that E=mc2. Nobody says the consensus is that the sun is 93 million miles away. It would never occur to anyone to speak that way.”

So remember, the next time someone tells you their view represents the “consensus” of scientific opinion, they are underlining the weakness, not the strength, of their argument. Just ask Galileo.