On Theory and Law

Clive Thompson wrote an interesting column in the November issue of Wired, "A War of Words". He reports on the view of physicist Helen Quinn that scientists are too tentative when they discuss scientific knowledge, and that this problem allows creationists the opportunity to mockingly refer to evolution as "just a theory" (as opposed to fact).

They're an inherently cautious bunch, she points out. Even when they're 99 percent certain of a theory, they know there's always the chance that a new discovery could overturn or modify it.

So when scientists talk about well-established bodies of knowledge — particularly in areas like evolution or relativity — they hedge their bets. They say they "believe" something to be true, as in, "We believe that the Jurassic period was characterized by humid tropical weather."

This deliberately nuanced language gets horribly misunderstood and often twisted in public discourse. When the average person hears phrases like "scientists believe," they read it as, "Scientists can't really prove this stuff, but they take it on faith." ("That's just what you believe" is another nifty way to dismiss someone out of hand.)

Of course, antievolution crusaders have figured out that language is the ammunition of culture wars. That's why they use those stickers. They take the intellectual strengths of scientific language — its precision, its carefulness — and wield them as weapons against science itself.

The defense against this: a revamped scientific lexicon. If the antievolutionists insist on exploiting the public's misunderstanding of words like theory and believe, then we shouldn't fight it. "We need to be a bit less cautious in public when we're talking about scientific conclusions that are generally agreed upon," Quinn says.

What does she suggest? For truly solid-gold, well-established science, let's stop using the word theory entirely. Instead, let's revive much more venerable language and refer to such knowledge as "law." As with Newton's law of gravity, people intuitively understand that a law is a rule that holds true and must be obeyed. The word law conveys precisely the same sense of authority with the public as theory does with scientists, but without the linguistic baggage.

Evolution is supersolid. We even base the vaccine industry on it: When we troop into the doctor's office each winter to get a flu shot — an inoculation against the latest evolved strains of the disease — we're treating evolution as a law. So why not just say "the law of evolution"?

Best of all, it performs a neat bit of linguistic jujitsu. If someone says, "I don't believe in the theory of evolution," they may sound fairly reasonable. But if someone announces, "I don't believe in the law of evolution," they sound insane. It's tantamount to saying, "I don't believe in the law of gravity."