There is an absolute existence that we try to describe through our system of beliefs. Where our beliefs differ from observable fact, it is necessary for us to alter our beliefs to fit the facts.
I don't think this is how a scientist approaches a topic. A more accurate statement would be...
There is an empirical existence that we try to describe via theories of how observed phenomena relate to each other. Because we are trying to describe the world as we sense it, where our theories conflict with observation (sensation), it is necessary to alter our theories to account for the new observation.
The idea that our empirical existence is related or accurate to an absolute existence is a philosophical (metaphysical) position and not scientific.
I think this is where Percy is coming from. A fundamentalist scientist could easily accept the above (altered) statement and work well as a scientist, while on a philosophical level feel (have faith) there is some disconnect between the empirical and absolute (temporary from a failed perspective or permanent for some other reason).
I agree that some scientists DO approach science in the way you describe, but they are in error. I also agree that some (perhaps most) creos approach science in the way you describe them as doing, but they are also in error (which seems to be what Percy is arguing).
I think there are people on both sides that simply will not listen to reason, nor entertain scientific methods or conclusions on a variety of topics. Errant creos are simply easier to spot as they are gathered around a specific subject to throw out scientific method. And they do so more readily.
My initial intention at EvC was to specifically engage in debate with ID theorists to get more information on their movement and arguments. It widened to working on my debate/writing skills in general, as well as promoting proper logic and scientific method in general. Ironically some of the most fervent "defenders" of science have been the most atrocious in its misuse and misunderstanding on subjects beyond direct EvC topics.
I think it is worth continuing debate for all of the reasons mentioned by others, REGARDLESS of whether a specific individuals will change their minds about something:
1) It improves one's base of knowledge and skill in writing
2) Some may actually change their position as they increase their base of knowledge
3) You yourself may actually change your position as you increase your base of knowledge
4) Others who are not involved with direct debate may come to understand something they would not otherwise.
holmes
"What a fool believes he sees, no wise man has the power to reason away." (D.Bros)