Fact filtering in the pursuit of truth
By Chet Raymo, 06/14/99
Last week this column took note of two explanations for the fossils known as ammonites. These animals in stone look like serpents curled upon themselves, or the tightly coiled horns of miniature rams.
One story, common in medieval England, told how St. Hilda turned snakes to stone. In fact, these fossils are common in rocks around Hilda's convent at Whitby.
The other story tells of creatures that lived in oceans tens of millions of years ago, died, fell into sediments on the sea floor, were petrified by natural chemical processes, and then lifted to their present positions above the sea by geological forces acting over eons of time.
Which story is true? Can we say with confidence that one story is truer than the other? Does ''truth'' matter?
These questions may sound silly. Surely, no one today believes Hilda turned snakes to stone. For one thing, fossil ammonites are found all over the world, even in the high Himalayas. Hilda would probably not have been so global in her miraculous powers.
But a substantial number of people today believe things about the origin of fossils that are equally preposterous. And others, including many PhD postmodernist scholars, say that the ''scientific'' story is no less a cultural concoction than the story of Hilda, and, recognizing this, that we should choose our ''truth'' on the basis of which story best advances an appropriate social agenda.
Science is just another kind of politics, say these post-modernist
critics. The important question to ask about a scientific idea is not
''How reliably has it been tested?,'' but ''Who stands to gain?''
For example, Native American creation stories are as true as stories of the Big Bang, say the science critics. To call the former ''myths'' and the latter ''Science'' (with a big self-assertive S) is just another kind of Eurocentric imperialism, no less arrogant than the taking of land and the killing of people.
Furthermore, they say, by demoting Saint Hilda in favor of James Hutton, Charles Lyell, and Charles Darwin, we may be guilty of a touch of patriarchal pretension.
All of which raises the following questions: Can we trust science? Is
''truth'' a matter of who has the power? Are we free to believe whatever
makes us feel good?
Well, of course, the great thing about the late 20th century - in many parts of the world - is that we are indeed politically free to believe whatever we want. One can believe that Hilda turned snakes to stone without any fear of being burned at the stake or branded as a heretic. People may snigger, but they won't put you in thumbscrews.
But morally the matter is rather more complicated, and each of us must take a stand on what we choose to believe. Thomas Huxley, Darwin's friend and champion, made this manifesto: ''My business is to teach my aspirations to conform to fact, not to try and make facts harmonize with my aspirations'' - to which most scientists would say ''Amen.''
The problem, of course, is to know a fact when we see one.
Which is why so many of us choose not to rely upon our own fallible faculties, but instead give cautious allegiance to the ''filter'' of science, as described by chemist Henry Bauer in his book ''Scientific Literacy and the Myth of the Scientific Method.''
Going into the top of the filter is the whole range of possible beliefs - from Hilda to Hawking, from the National Enquirer to the American Journal of Physics. The first step of the scientific filtering process usually involves a request for funding from an agency. These proposals are reviewed by other scientists. Nonsense, stupidity, and pseudoscience are screened out at this stage.
The second step is getting an idea published in the peer reviewed scientific literature. This generally eliminates egregious bias, experimental or mathematical error, or outright dishonesty.
Useful ideas in the primary literature get cited in other work, and are adopted by other scientists to explain their observations. Ideas that pass this test make it into the secondary literature - summary articles in prestigious journals. Before this happens, subtle mistakes and ingenious fraud are usually detected and corrected.
Ideas that are adopted widely and pass the test of time end up in textbooks. Blind alleys and obsolete ideas fall by the wayside.
Even textbook ''facts'' are subject to long and careful scrutiny by the scientific community as it submits orthodox ideas to the crucible of ever more careful experiments and observations.
What comes out the end of the filter may not be Truth with a capital T, but the fact that science has been so successful as a way of knowing - and such an effective basis of technology and medicine suggests that what comes out of the filter has a satisfying objectivity.
Is the filter of science foolproof? Of course not. But if post-modern critics of science have a more reliable way of generating ''facts,'' let's hear it.
Chet Raymo is a professor of physics at Stonehill College and the author of several books on science.
This story ran on page C2 of the Boston Globe on 06/14/99. © Copyright 1999 Globe Newspaper Company.