Monday, November 17, 2008

Scientific Consensus

Casey Luskin at Evolution News and Views reminds us of a quote from the science fiction writer Michael Crichton (Jurassic Park, Andromeda Strain, et al.) who passed away just recently. Crichton gave a speech in which he was very critical of the tendency to cite the "scientific consensus" in order to clinch some debating point:

"I want to pause here and talk about this notion of consensus, and the rise of what has been called consensus science. I regard consensus science as an extremely pernicious development that ought to be stopped cold in its tracks. 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. Whenever you hear the consensus of scientists agrees on something or other, reach for your wallet, because you're being had.

"Let's be clear: The work of science has nothing whatever to do with consensus. Consensus is the business of politics. Science, on the contrary, requires only one investigator who happens to be right, which means that he or she has results that are verifiable by reference to the real world. In science consensus is irrelevant. What is relevant is reproducible results. The greatest scientists in history are great precisely because they broke with the consensus.

"There is no such thing as consensus science. If it's consensus, it isn't science. If it's science, it isn't consensus. Period....

"I would remind you to notice where the claim of consensus is invoked. 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."

(Michael Crichton, "Aliens Cause Global Warming," reprinted in Wall Street Journal, November 7, 2008.)

The context of Crichton's remarks was the use of "scientific consensus" in the global warming debate, about which he was a skeptic, but his point applies equally well to the debate surrounding the origin of the cosmos and the origin of life. Dissenters from the consensus are often brow-beaten by the assertion that all "real" scientists believe life evolved by Darwinian processes when in fact that claim is not true and would be beside the point even if it were true.

"Darwinian processes" means that only physical mechanisms have been at work in the creation of the diversity of structures, functions, and operations found in living things. In other words, Darwinian processes (e.g. natural selection and random mutation) exclude any role for mind and intention, and it's simply untrue that all real scientists embrace the exclusion.

Even were it true, however, Crichton's point was that it doesn't mean much. Many if not most great advances in science came about because people who stood outside the mainstream refused to be cowed by the dominant view. This was certainly true of the work of Copernicus and Galileo and even of Darwin himself. It was true of Dalton, Einstein and Le Maitre. The fact that a majority of experts believe something should cause us to respect their theory, but it does not follow that what they believe is correct.

Crichton trenchantly notes in his speech that the club of consensus is usually brandished only when there is a lack of confidence in one's theory. It's a bit like the oft-heard claim that evolution is as well-established as the theory of gravity. This is simply false, and is shown to be false by the fact that one never hears a physicist say that the theory of gravity is as well-established as the theory of evolution. Physicists would never think to make such a claim because it's so obviously laughable.

RLC