What I'm saying is that science -- scientists, actually -- have simply defined God out of the problem. This assumption explicitly precludes the development of such a test as you're demanding, rejecting a hypothesis before it can even be proposed.
The question is whether there's any real justification for making such an assumption.
The situation reminds me in a lot of ways of Einstein's explanation of how he went about developing his theory of relativity. Among other things, he went back to the governing assumptions in the then-prevailing Newtonian physics, including the assumption that time passed at the same rate for all observers. Einstein's great leap was in questioning that assumption, with the result that the definition of "nature" had to change. (Yes, I'm oversimplifying.)
Newtonian physics is still extremely useful, of course, because most of what we deal with is systems where the velocities and accelerations have negligible relativistic implications. In most everyday cases, the relativistic component is tiny -- but nevertheless there. In some cases, however, relativity is a major factor, and cannot be ignored.
The scientific method is based primarily on the assumptions that effects have causes, and that physical phenomena are constant over time. These are powerful concepts. But why things are that way can as easily result from the fact that God is consistent, as if they are true because of some necessary and sufficient condition that governs an atheistic universe.
In most cases, as with Newtonian physics, the scientific method can operate without having to address those root causes. It would work in either case. In some cases, however, there may be a need to address the underlying assumptions, and to reassess the boundaries of what is "natural".
The origin of DNA-based life is potentially one such area, given that the probabilities of it randomly occurring are so very small. The prevailing scientific theory of "nature" -- the atheistic universe -- doesn't seem adequate to the task of explaining the development of life through random combinations of atoms. Those interested in Intelligent Design are able to answer some of the difficulties by pushing on the definition of "nature," and positing that it is the handiwork of some creative intelligence.
Just as relativistic systems are evidence of time dilation, DNA-based life could well be evidence of the actions of an intelligent agent -- God, if you will -- and therefore the sort of repeatable scientific evidence you're looking for.
This approach obviously introduces some metaphysical problems of its own, even as it solves various other "origin" problems.
But you are simply rejecting the idea out of hand, because it doesn't fit your definition of what's "natural." God cannot have a role, because you've already assumed that God cannot have a role. This is why I call it an ideological position: you've already decided on your answer, because your assumptions are not to be questioned.
Let's call it given that a Creator God exists, as described in the literal view of Genesis (which is pretty much all that creationism and ID have to work from - a acknowledgment of the use of metaphor would pretty much obviate the argument).
Now...look at all the discoveries that have been made over the past few centuries concerning How Things Work (tm) - physics, cosmology, astronomy, chemistry, biology. There has certainly been a great deal of order found in the way things work. But, from a scientific standpoint, one doesn't say,
"Hey, the way things are set up is internally consistent and stable - someone or something musta thought it up!"
That simply isn't the way science works, at all.
And again, how would you design a scientific experiment to test for the existence of a Creator? The test would have to give different results depending on whether things were Created or not, and those results must be predicted before the fact, not pointed to afterward as evidence. In other words, you have to come up with an empirical test as such:
If a Creator God (note the specific type of God) exists, then Condition X will apply.If Condition Y applies, then a Creator God cannot be shown to exist.
Man, I hate all this HTML...bleah. Anyway, the big question is, what is Condition X? How do you figure out what would be a sufficiently definitive test?
[I'm quoting out of order here, for flow-of-thought reasons]
God cannot have a role, because you've already assumed that God cannot have a role. This is why I call it an ideological position: you've already decided on your answer, because your assumptions are not to be questioned.Au contraire. Let me be brutally clear here - God may or may not exist. Science just doesn't care. The Universe looks and acts like it came into existence 13 billion+ years ago, and science treats it as such, because that's where the evidence as we currently understand it points. To say that this denies the existence of God...well, it beggars the imagination. There is no evidence to suggest God is not a guiding force behind evolution. OTOH, there is no positive evidence for it either. The idea has been neither included or excluded - it's just kinda floating out there.
As for assumptions not being subject to revision - that is certainly a misrepresentation. All science is subject to constant review and revision, and discardment if need be. If a theory were posited that could explain in a consistent manner how life on Earth came to be, and could also explain how and why the previous explanation (evolution through natural selection)is incorrect, then that theory would be accepted. Even if that theory included a Designer. Intelligent Design fails to do that.
The origin of DNA-based life is potentially one such area, given that the probabilities of it randomly occurring are so very small.Two problems here. One, your use of the word "randomly." While chance does play a major part in evolution, the subprocesses (i.e. natural selection, the laws of physics and chemistry) that drive evolution are anything but random. It's a serious misrepresentation to say that evolution is a random process. Secondly, your use of the probability argument. While the probability of a particular sort of life (i.e. humans) evolving may be small, the chance of some form of life developing is much greater. Frankly, too, tons of things that happen and continue to happen are highly improbable.
Given our current laws of physics, the chances of a universe matching the description of ours (sounds like an Most Wanted poster, don't it?) are far more remote than the chances of Life As We Know It evolving on Earth. Yet here we are. The very beginning of life is of no real consequence to evolution. Evolutionary theory could be likened to a roadmap for an odd sort of Zen one-way traveler - nothing about the city you're coming from, and precious little about where you're headed to, but lots about the Interstates, rest stops, tourist attractions and towns between the two places.
But you are simply rejecting the idea out of hand, because it doesn't fit your definition of what's "natural."
Or, indeed, anyone's. God is a supernatural entity by any reasonable definition. If God is a natural being, then He would at the very least not be God Christians believe in, and would be irrelevant to this particular debate.
My take is this - evolution is true and factual, and the Earth and Universe are very very old. I do not read Genesis 1 literally, and thus have no trouble reconciling the foregoing notions with faith in God.
The problem I have with the argument you present is that it basically boils down to an argument from incredulity - you can't get your head around the notion that life evolved from very basic forms, and thus don't believe it. The idea of a Creator God taken from a literal reading of Genesis 1 is comforting and sensible, and so you stick with it. I have no problem with that. I do have a problem presenting that idea (or a thinly cloaked version of it) as something that should be taught in schools as a competing scientific theory.
Regards,
Snidely