The first time I ever heard a Fundamentalist Christian say evolution was just a theory, not a fact, I wanted to hit my head against the wall so that when I stopped, the dull ache in my head would at least go away.
I couldn't decide whether he was being deliberately obtuse or really was that ignorant. I think, in some cases, the ignorance is genuine. But some of the people who make that confident remark in defense of creationism know what they are doing: manipulating the language.
There's a great article in today's Washington Post, by Steve Olson, author of the book Evolution In Hawaii, that begins with an excellent definition of the term "theory." Actually two definitions of it, the layman's term and the scientist's term.
I've given these two definitions many times myself, including several times on message boards at Beliefnet (sorry, it was so long ago that trying to get you a link would be nearly impossible).
Basically, as Olson and others, including me, have pointed out, the term "theory" does double duty and has two separate meanings that are almost at odds with each other.
When a layman uses the term "theory," he usually means an opinion or a hunch, not something factual. For example, he'll say, I have a theory as to why the new baseball team in Washington is going to be so popular. They haven't had a team of their own in so many years.
Probably it's a good theory. But unless this guy's a pollster and took a survey, it's just his own opinion, just his theory.
But when a scientist talks about a theory, whether it's Einstein's theory of relativity, or Darwin's theory of evolution, it's a lot more than mere conjecture. It's an observation based on the accumulation of a great deal of scientific evidence from the field. It's something that has been laboratory tested and is accepted as factual.
When a scientist talks about a hunch or opinion, he would use the term hypothesis. So, he might start with a hunch, a hypothesis that if you throw an apple in the air, it will always come down and hit you in the head because of gravity. He will then test his hypothesis over and over again in a laboratory and come up with the theory of gravitation.
Only after a hypothesis has been tested many times, by many different scientists, will it be accepted as a scientific theory. So, it has the accumulated weight of many minds in the field vouching for its accuracy as the best theory for explaining all the evidence.
After describing all this much more clearly than I just did, Olsen does a surprising turn. He says that hypotheses such as creationism and intelligent design should be discussed in schools alongside the theory of evolution.
As Olson claims, and I agree, neither creationism nor intelligent design should be taught as actual science or as accepted mainstream scientific alternatives to the theory of evolution because they are not that. But there does need to be debate between biologists who understand the theory of evolution and those theologians who oppose it. As Olson points out, whenever science has debated and defended its position, it has acquitted itself well and come out ahead.
High schools should have, not only hard science classes where evolution is taught, but philosophy of science or history of science classes where alternative theories can be explained and debated. That probably won't make the Fundamentalists happy, but it will shed more light on the debate for ordinary laymen like you and me.
Another thing that scientists need to do (Olson doesn't mention this; it's my own opinion) if they are going to stop the endless attacks on science in red states, is to explain the importance of accepting the theory of evolution and give some pracitical applications of evolutionary theory.
One very practical application, for example, is in the medical field. If we don't understand evolution, natural selection and the ability of living organisms to adapt and pass on the traits that are most likely to ensure their survival, we will not be able to understand why it's important not to over prescribe antibiotics for viruses. These powerful medicines don't work on viruses, but for years doctors prescribed them to patients thinking they would do little harm. But the harm they did was to cause bacteria to mutate - or evolve into deadlier strains with greatly increased resistance to these drugs.
Another reason to understand evolution is because then we can appreciate how difficult it has been to discover a vaccine for HIV/AIDS. The virus that causes this deadly disease mutates so rapidly and adapts so efficiently that it's been impossible to come up with an effective vaccine.
Doctors need to understand these things. So do ordinary, educated laypeople. And if children from Kansas are forbidden to learn evolution in school, it's going to eventually put that state's medical profession at risk. I don't know about anybody else, but I don't want a doctor who doesn't understand basic, mainstream science. Even if that means I have to avoid Christian doctors from red states. And that might be very much what's the matter with Kansas.