Thursday, February 19, 2009


The Theory of Law

Clive Thompson, a contributing writer at The New York Times Magazine and a former Knight Science-Journalism Fellow at the Massachusetts Institute of Technology, has a theory. Noting that creationists take advantage of the language used by scientists to inculcate doubt in the general public's mind about evolution, he seconds the call of Australian-born physicist Helen Quinn for the scientific community to revise scientific terminology. The obvious example is the use of the term "theory," as seen in this letter in the Tifton (Georgia) Gazette by an otherwise articulate and reasonable-sounding man, who has been obviously mislead about the present state of science by the Discovery Institute and its minions, through such things as its list of "dissenters" from "Darwinism" and the supposed "icons" of evolution. Central to his position, however, is the confusion over the meaning of "theory":

[A]s a parent, a Christian, and a concerned member of society, I simply cannot sit back and see evolutionary theory espoused as "fact" without offering my understanding of "the rest of the story." The truth is that evolution is, and always has been a "theory;" it has never been definitively proven ...

Thompson correctly diagnoses the problem:

[F]or most people, theory means a haphazard guess you've pulled out of your, uh, hat. It's an insult, really, a glib way to dismiss a point of view: "Ah, well, that's just your theory." Scientists use 'theory' in one specific way, the public another -- and opponents of evolution have expertly exploited this disconnect.

The justification for using tentative language in science is obvious:

Last summer, Australian-born physicist Helen Quinn sparked a lively debate with an essay arguing that scientists are too tentative when they discuss scientific knowledge. They're an inherently cautious bunch, she points out. Even when they're 99 per cent 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 characterised by humid tropical weather."

So what do Thompson and Quinn propose:

There is a defence against this: a revamped scientific lexicon. If the anti-evolutionists insist on exploiting the public's misunderstanding of words such as '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 argues.

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. ...

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 reasonable. However, if they announce, "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."

I don't agree. While the boundaries in science between "law," "theory" and "hypothesis" have always been somewhat fluid, a "law" has never been just a "grown-up" theory. Scientific laws are, for the most part, about simple physical relationships that are subject to direct empirical confirmation. Newton's law of gravity describes how two objects act in their mutual gravity fields (under "normal" conditions) and can be repeatedly tested under easy to reproduce conditions. Theories, on the other hand, are mostly broad explanations of the interplay of the many physical properties that go into complex systems and have to be tested piecemeal and, often, indirectly.

What, for example, would the "law of evolution" entail? Common descent? But that's not in any sense a "law," it is a fact about life on Earth that could have arisen from many different, and inconsistent, natural causes, including natural selection, Lamarckism or some sort of development inherent in genetics. That, of course, doesn't even include non-natural causes, such as directed variation or progressive creationism.

Natural selection may come close to being a "law," insofar as, if the proposed conditions exist, the occurrence of selection is a logical conclusion from the premises. But even the strongest adaptationists don't claim that natural selection is coextensive with evolution, which has additional causes, such as genetic drift. It wouldn't be close to correct to call natural selection "the law of evolution."

Worst of all, scientists would have to agree to such a change in terminology and that would necessarily require widespread discussion within the scientific community. How would the creationists be kept from learning of this change and the reasons for it? If their aim is discredit science and dismantle the trust the public generally has in scientists, and it is, what better weapon could scientists hand them but an admission that they were trying to practice semantic jujitsu on the uninitiated?

Not only would calling it "the law of evolution" be incorrect, it would be a public relations nightmare far worse than the present misapprehension of the scientific meaning of "theory." There is no linguistic "magic bullet" for the public misunderstanding of science. And even if there were, it would not lie in sleight of hand or adopting the tactics of creationists. Being as honest and clear as possible and working to improve the science literacy of society may not be easy -- and certainly won't be quick -- but it is the only path consistent with the principles that science itself is practiced by.


Update: John Wilkins has a much more detailed (and accurate) description of the relationship between theory, law and hypothesis in science.

I do wonder if this particular confusion and its aid to creationists is one reason why they get more traction in anglophonic countries.
Whenever these discussions about "the theory of evolution" come up, I immediately think of "the theory of flight", "the theory of the earth", "the theory of antennas", ... or even "the storming of the Bastille", "the end of the month", or "the fire of Chicago".

Is flight a theory? Is the earth a theory? Are antennas a theory? Is the Bastille a storming? Is the month an end? Is Chicago a fire?

Tom S.
The problem has little to do with terminology and more to do with people prefering to reach a conclusion irrespective of any rationality of the arguments used to reach said conclusion. So, do keep the word theory, for if nothing else, it is at least easy to point out to people who misuse the term that they should perhaps have a look in a dictionary.
I'd vote to abandon Theory for something else. Certainly not Law; Thompson and Quinn should know their definitions better than that.

I'd vote to abandon it not just because "theory" is confused in the mind of the public, but that it is routinely used in some scientific endeavors to represent things that are not a scientific consensus.

For example: de Broglie and Bohm's Pilot-Wave Theory, or Haeckel's own discredited Recapitulation Theory. Even String Theory (though it should be in the plural at that) is weighted almost entirely on the mathematical, not the evidentiary, side (at least not yet).

Even though those theories and those like them are often given in lowercase, the message is clear: scientific theories as the term "theory" seems to be used in science are "merely" encompassing explanations for a phenomenon, without an indication of the amount of evidence or consensus reached. Capitalizing the T does not seem sufficient to distinguish theories for which there is a preponderance of evidence.

We aren't going to be able to get theorists to scale back to using "hypothesis" instead of "theory" because hypothesis isn't the right connotation, either: they are systems of hypotheses.

When I was mulling over this question a while back, a decent word that came to mind was "Account". "Account of Evolution" sounded better than some of the alternatives I was thinking of, but perhaps even here, Account would be seen as too overloaded a word.

Any votes for a replacement word?

Any reason why we shouldn't come up with a replacement word?
Any reason why we shouldn't come up with a replacement word?

No reason why not (though my sympathies are with Hawks) but plenty of doubt about the scientific community, which is conservative in its methods, adopting a replacement.

Maybe "explanation" would be closest to the scientific meaning of "theory" ... the Explanation of Evolution. Better yet (but more words, and therefore less likely to be adopted), the Comprehensive Explanation of Evolution. While I wouldn't put anything beyond creationists, saying "it's only a comprehensive explanation" would carry less rhetorical weight than "only a theory."
While I wouldn't put anything beyond creationists, saying "it's only a comprehensive explanation" would carry less rhetorical weight than "only a theory."

*laugh* If it was just a question of adding Comprehensive, which I like as well, we could just as well add that to plain old Theory ;)

We've always had the option of adding Scientific in front, as well, but given how often we give in to expediency, a replacement word would have to be able to stand on its own without further qualifiers!

(That said, Comprehensive is certainly subject to less of a pejorative tone than creationists manage for Scientific)

Personally, I like Explanation, Account, Understanding and perhaps Low Down.
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