I couldn't have come up with a more effective explanation of why it is impossible to have a rational discussion about religion with fundamentalist Christians. I found this in a piece by David Ferguson on the rawstory.com:
"Presuppositional apologetics is a school of theological thought that says all rational thought flows forth from the word of God and that no science or scholarly investigation is possible without first accepting that the Bible is the word of God and absolutely true. Outside of that belief system, it says, there is no possible basis for argument with a non-Christian because everything they believe is false."
There you have it in a nutshell. The rest of the world is wrong!
Let's deconstruct this claim from Dr. Jason Lisle of the Institute for Creation Research. First, his premise is faulty on its face: "Rational thought that flows from the word of God" is a theory dependent model of reality based on human theories about reality. The Bible consists of ( sometimes coherent and other times incoherent) theory dependent models created by human beings during a time of blind ignorance of the nature and workings of objective reality. In other words, human explanations for natural phenomena that wasn't understood.
The next argument is "God inspired the humans who wrote the Bible." Again, the concept of an anthropomorphic God is a human construct. It is a theory dependent model that projects an omniscient and omnipotent entity onto the universe and its workings.
Suffice to say, every explanation of reality is a human theory -- even science.
Now this form of apologetics has found the final method of picking and choosing what to believe and ignoring the fact that everything we consider objective evidence comes from subjective interpretation.
I repeat! Every law, theory, hypothesis, and explanation of reality is ultimately subjective. Consequently, they depend upon theoretical models created by humans.
The difference is, science continues to question and presuppositional apologetics has found a way to defend itself by closing itself from further investigation.
In other words, for presuppositional apologetics to have legitimacy to those who profess it, it must remain closed to every other form of reasoning. Its primary axiom does exactly that. And by doing so, its legitimacy is limited only to those who accept its premises.
So why do I care if an isolated group of people want to defend their beliefs with this kind of recursive thinking? I don't until they're not isolated and begin to influence the rest of us through their pressure on government.
These folks are making inroads in education by promoting religion as science. In those states where laws have been passed allowing this transgression, the children are being robbed of their futures. As a country, our ability to compete in a modern world is diminished.
Our current lack of science research funding is causing our scientists to consider moving to other countries, while powerful lobbies are using religion and anti-scientific sentiment to benefit their short term business agendas.
This kind of nonsense is the latest phase in the dumbing down of America. How much further can it go? How about Christian Televangelist, Pat Robertson, claiming that gay men in San Francisco wear special rings that give you the AIDS virus when you shake their hands. Is that dumb enough for you?
But wait. He can't be right. So far I haven't been able to find evidence for his claim in the Bible.