Tuesday, October 6, 2009

The nature of science

As I wrote on Saturday, my post about evolution aroused quite a response. Here's a list of the blog reactions that I've found so far:

A Simple Prop
Freedom Log
The GeoChristian
You Call This Culture?
Exploring Our Matrix
for the Sake of Truth
The Clever Badger

(That last one is interesting: I've been badgered by quotes before, but never quoted by a badger.)

John Lynch's post at A Simple Prop started the whole chain reaction. Otherwise, I'm sure my comments would have been ignored like nearly everything else I post. So thanks, John. I guess.

As I wrote before, I expected certain classes of response: (1) Affirmation by anticreationists trying to make other creationists look bad, (2) Denial by antievolutionists convinced that I'm ignorant, brainwashed, or just evil, and (3) intelligent interaction by those who truly understood what I said. I got several responses in each of these categories. I found it very interesting that emails in category (3) tended to open with "Dr. Wood" while emails in category (2) opened with "Mr. Wood." And then there was the kind soul who merely explained that my "problem" is that I'm "ignorant." I guess that's category 2?

I did not anticipate the level of confusion the post seems to have generated. I believed (and still do) that what I wrote was quite clear and straightforward. Evolution is science, there is evidence for it, but I don't believe it. I never said it was true. I also never said that all the evidence favors evolution, nor did I say there was no evidence of creation.

The confusion requires me to backtrack to some basic definitions, which in this discussion are unfortunately but inevitably tied to propaganda agendas. I'm going to begin with my understanding of science, and please realize that this is my understanding of science as a scientist. This is not some outsider (mathematician, computer programmer, engineer, philosopher, etc.) commenting on what they think science is or what they want it to be.

I describe science to my students as a means of explaining the natural world using a criterion of correspondence. As far as I can tell, that is the basic thread that unifies all the stuff we would think of as science. By correspondence, I mean that our explanations in science must correspond to what we observe in the natural world. Explanations that correspond well are preferred over explanations that correspond poorly. Correspondence is the major feature that sets science apart from other human endeavors.

I can already hear the howls of protest. Anticreationists insist that the explanations of science should never invoke the supernatural. I see this requirement as sort of pragmatic (due to the unknown nature of the supernatural) but also very much ideologically-driven (in order to demarcate science from "pseudoscience" like creationism). Obviously as a creationist I reject this requirement. Pragmatically, I think that the supernatural can be discussed in science if that supernatural agent is somehow knowable. Since I think God is not only knowable but desires to be known, He becomes a valid agent to posit in science.

On the other side, antievolutionists often want to limit science to that which can be observed directly or in the present or repeatably. Or they might try Norm Geisler's trick of distinguishing between "operation science" and "origin science." Like the exclusion of the supernatural, I find none of these distinctions helpful for anything other than trying to exclude "the opposition" (in this case, evolution) from the realm of legitimate science. Direct observation and repeatability are pragmatically useful for establishing correspondence between an explanation and reality, but they are not required.

What this description leaves to be determined is whether an explanation is particularly "good" or "useful" to scientists, the people actually doing research. A good explanation corresponds to lots of data (which we call "evidence"), but it still might have inconsistencies, or pieces of data that correspond poorly to the explanation. Despite the presence of these inconsistencies, it's still quite reasonable to call something "good science" if it corresponds to lots of data (i.e., has a lot of evidence).

I also see an important corollary to correspondence in the form of prediction. A good scientific explanation will imply something about the world that you might not yet have observed. "Good science" makes lots of predictions about the world, and it keeps us busy making new observations. "Bad science" leaves us with nothing to do, even if the correspondence between the explanation and reality is (or could be) quite high.

Since this post is already too long, I'm going to write a little more about hierarchies of explanation another time. Stay tuned. In the meantime, remember that I'm just a scientist, and I'm not widely read in the philosophy of science. I'm just trying to steer a course through a minefield of propaganda-tainted definitions of science while still retaining the essential ingredients of what we do as scientists.