I was having a discussion about evolution over on a thread at Skeptic Blogs, a case of someone, not necessarily a denier, thinking there were genuine issues with evolution that needed answering. I answered his five points with ease - some typical misconceptions. But it did make me think about the epistemology of Creationists and evolution deniers; something which I have thought about before and want to share (it is lifted from my latest Skeptic Blogs post).
I was having a discussion about evolution over on another thread of a post I made from the other day. After explaining a few misconceptions and showing that evolution really does have a good smorgasbord of evidence to support it as a theory in a way that promotes bewilderment in the face of denial.
It reminded me of this issue with denial:
Denial of evolution, usually from a presupposed position of theistic necessity (very few atheists deny evolution!), comes in two shapes:
1) claims of absence of evidence
2) claims of problematic evidence
The first claim should be easily dismissed since in EVERY SINGLE scientific theory and discipline, we start off with absence of evidence. Evidence is gathered, hypotheses are formed, but if we adopted a method which ran like "we cannot believe a theory which is not supported by 100% evidence" that would mean we would never believe anything, and we would give up trying to find anything out right from the offset!
An example, in evolutionary terms, would be so-called "gaps in the fossil record", which is a claim that is itself debated.
The second claim seems to involve problems which are not terminal. What I mean by this is that if the claims were terminal, then no one would believe in evolution. For example, if they found undisputed evidence of a slew of rabbit fossils in Jurassic rock strata, evolution falls apart quite considerably. But these sorts of problems brought up by Creationists are not so terminal, and are almost always refuted.
So what is my point?
Evolution is defended by a plethora of evidence across a staggering number of disciplines. I often hear from Creationists claims like "I don't believe in evolution because there are gaps in the fossil record" or "I don't believe in evolution because the mutation rates do not cohere with the claims of evolution" and so on. This really annoys me. I will be slightly arbitrary in my approach here, but let me set it out like this. Imagine that the amount of evidence supporting evolution is 500,000 units of evidence across dozens of disciplines. Now the claim that hang on, there is a gap of knowledge or an unknown that should invalidate all that evidence is a stupendous piece of epistemology.
Likewise, if a Creationist claims that 1 unit of non-terminal evidence defeats all the 500,000 units of positive evidence, then they are throwing the baby out with the bath water and they are exhibiting some rather bizaare epistemology.
You see, if scientists, when presented with difficult evidence, just threw up their hands and said "Well bugger me, that does that theory in, I'd better give up and take up canoeing", then we would never get anywhere. What happens is the scientist seeks to explain that problemtic evidence or eliminate it.
So what happens with your standard Creationist is that they reject ALL of the MOUNTAINS of evidence as being false on account of a minor piece of evidence either being missing or being problematic. Epistemologically, this is crazy. All that positive evidence being rejected out of hand in the face of a tiny missing piece of evidence or problematic piece of evidence.
This leaves the denier with an even bigger problem - how do they then explain all that positive evidence which is there having rejected the theory which utterly explains it? How then are endogenous retroviruses made any sense of since the baby has been thrown out with the bath water.
Of course, there is no bath water. Just a good, solid, well-fed baby.