Foundationalism: The theory that at the bottom of all human knowledge is a set of self-inferential or internally justified beliefs; in other words, the foundation is indubitable and requires no external justification.
Ironically, the "liberal" Christians in America and the "conservatives" suffer from the same illness. Both are beholden to a scheme that philosophers call "foundationalism," and that leads to their intractable fighting. Since their foundations are different (thought related), they are cursed to shout past one another forever, for they are each caught in a philosophical hell called infinite regression.
For the conservative, the sacred text of Christianity is indubitable, established by an internal and circular reasoning: "The Bible claims to be God's truth, so therefore it's true." Many evangelicals have a more sophisticated view of scripture than this, but they're still destined to a life of establishing the veracity of the Bible in the face of contravening evidence and opinion:
"I believe X, Y, and Z because it says so in the Bible."
"Well, how do you know the Bible is true and accurate?"
"I believe the Bible because the apostles died for its truth, and people don't die for a lie."
"What about the 9/11 terrorist?"
"The were deceived. They didn't know they were dying for a lie. The apostles had seen Jesus and lived with him, so they knew he wasn't a lie."
"What about the followers of Jim Jones and David Koresh?"
"Well, the Bible is really true because of the reliability of the original manuscripts."
"Do we have the original manuscripts?"
"No, but we have some pretty old ones that are close to the originals."
"How do we know they weren't changed in the early years?"
"Because we have faith in the historical process by which the early manuscripts were copied and distributed."
"So your faith is in history?!? Does that mean you believe that history is indubitable?"
"Not all history. Just our history."
"Based on what? Why is biblical history certain and sure?"
"Because it accords with reality."
And so on, ad infinitum (2008:18, 19).