I was all set to write a post asking what it meant to “use” evolution. But then a commenter went ahead and did it for me, and added some smart thoughts on expertise to boot! I’ll try to write more soon, but in the meantime, think about this:
Regarding the dualism of the Pakistani doctor, is it possible that the evolution that he accepts and the evolution he rejects really are two different things? Perhaps the “evolution” that he accepts is an understanding of how mutations occur in his patients and how deleterious mutations in the human genome can accumulate if they were not selected against, and how micro-organisms mutate and adapt to their environment, and the specific problems with over-prescribing particular anti-biotics. Whereas the “evolution” he rejects is the assertion that modern humans and modern chimps are both descendents of a common hominid ancestor. The modern synthesis proposes that the same process that produces superbugs today also produced modern humans over the past 6MY. But the evidences for human evolution (fossils, for example) are different than the evidences for superbug evolution and less accessible to a dr. in daily life than the evidences for superbug evolution. And though these two things are both “evolution,” they are conceptually distinct. In other words, I’m wondering whether it’s possible that the evolution the Pakistani Dr. accepts and the evolution he rejects are actually two different ideas in his mind, rather than the same idea accepted in one context and rejected in another. I just don’t know if that hypothesis has been explored.
A further thought I had about this, given the role that authority plays in our beliefs, is this: I’ve often heard it wondered why creationists easily accept the pronouncements of scientific authority on topics like the melting point of steel, how far away Andromeda is, how closely cell towers should be placed to get good reception, or how far an English swallow can carry a coconut, but then when it comes to how old the earth is, they are suddenly skeptical. It’s sometimes stated as, “they implicitly accept evolution everytime they use their satellite TV or drive over a bridge, but then they turn around and say men and dinosaurs lived at the same time!” But it seems to me that there is a difference in accepting an expert’s best guess as to what is going on in the present, and accepting his explanation about what happened in the past, or what he thinks is going to happen in the future. You bring your car to a mechanic and he says, “I can see your transmission is about to go out.” and you believe him. But when he tells you how he thinks it happened, or what he thinks is going to happen next, you think well, he might be right, but there’s also a chance that he might be wrong.
Creationists (or those who doubt global warming, to pick another topic Professor Kahan has studied) don’t necessarily doubt the ability of credentialed experts to make careful measurements and report their observations and explanations with reasonble integrity. But isn’t it natural to have a different standard of what it takes to be convinced regarding an explanation of what happened in the past or a prediction of what’s going to happen in the future? We’re used to relying on authority, but we’re also used to the idea that even a pretty reliable authority is probably not infallible, and might be more reliable in one area than another. So the inconsistency of believing someone on one topic but not another isn’t really an example of KD or at its core really inconsistent or irrational, is it?