Language, fundamentalism and rationality.
Alright... as this is new-ish thinking to me, this topic might not be as well presented and explained as I might've liked, but you've got to give your first try somehow, so here goes:
This post will make more sense if you're familiar with Wittgenstein's later work.
He said that the meaning of a word is how we use it.
If someone shouts "Quie!" in order to find out what the time is, the meaning of the shout "Quie!" is a signal to request the time. He likened language to playing a game. In order to play a game you follow the rules, and it's the rules that our logic is rooted in. However, different games have different rules so different 'logic' involved. Your strategies in a game of chess are very different to those in a game of Othello.
One famous claim that Wittgenstein made was that the psychological language game was very different to the empirical one. The empirical one is where we describe facts of the world, e.g.
"There is a blue chair in the corner"
"Water molecules contain one oxygen atom and two hydrogen."
It is the language game we use for science.
He claimed that many psychologists were trying to treat psychological objects as if they were empirical ones and this was a cause of many philosophical problems. Part of his 'private language argument' was to try and show that conditions necessary for the empirical language game to work (e.g. objects that existed in dependently of our perception) weren't present in psychology. So beliefs and intentions aren't 'things' that can be explained 'physcially'. They are more like numbers in that respect.
So what has this got to do with religion?
There tends be two types of thinking in religion, one that is more common to fundamentalists and one that is more common to moderates. (when I say 'moderates', I think you Americans would call them 'liberals' - a little transatlantic translation for you there! )
A Christian will tell you that their religion is truth. You then ask:
"Is this truth crystal clear like 'that table is blue' or 'salt dissolves in water'?"
The fundamentalist will say yes and talk about historical facts and scientific evidence.
The moderate will say 'not quite...' and start talking about mysticism.
To put it in Wittgenstienian terms, the fundamentalist claims we can talk about religion in our empirical language game while the moderate is playing a different one.
The difference is quite substantial.
The most obvious one is the exclusivity of truth.
In our empirical language game, either the table is blue or it is not.
In other language games where 'truth' has a different use and therefore a different meaning, truth need not be exclusive. This is why modern moderates see no contradiction in saying that all religions are true. This means that they are more open to accepting (let alone tolerating!) of other views.
Fundamentalists, on the other hand, believe that there's one truth and that it is clear and that anyone who denies it is atleast wrong, maybe even dishonest!
Another major difference is the 'truth maker'.
The truth maker is what makes things true, so for science the truth maker is empirical reality - a scientific fact is true if it accords with empirical reality. In the empirical language game, the truth is independent of your feelings and ideas. If the table is blue then it is blue and whether you think it should be or not is irrelevent. When a fundamentalist makes the Bible (or rather, the tradition of interpretation they've been brought up in) their truth-maker, it over-rules any common sense they might have.
In his Case for Faith book, Lee Strobel admits to being able to make no sense whatsoever of the idea that a loving God would burn people in hell. Moreland carries on to give him a bucket load of sophistry to try and ease his mind (I think that he was one of the few people capable of writing that chapter!) which Strobel accepts, but in the 'Conclusion' chapter he admits that is still vexes him. Moreland makes a speech about how we might not fully understand something that makes a lot more sense in the bigger picture, but what we do know is that the Bible is true so we should accept what it says even when it doesn't make sense to us. The fundamentalist is willing to accept morals that are totally counter intuitive if it comes from their 'authority', because the truth-maker of their religious beliefs is independent of their natural humanistic values.
The moderate is different. Their language game of religious belief has a different truth maker. It's not completely dependent on their sentiments but it has to make sense to a degree. In short, if their Bible says something that makes no ethical sense, their truth maker leans more towards their ethical sense rather than what the Bible says. That's why moderates tend to be open to interpreting the Bible in humanistic ways. Fundies perhaps hate moderates much more than atheists - atleast the atheists admit that they're infidels!
The last difference is rationality.
As the fundamentalists make objective truth claims, their religious claims a falsifiable through philosophical/scientific investigation. According the theological non-cognitivists (the position that God has no meaning in the language game of empirical truth), fundamentalism is completely false. However, non-cognitivism doesn't have the same effect on moderates as their religion isn't tied to the empirical language game in the same way. Their 'God' can be a bit more mystical because it doesn't need to be a coherent empirical object. Infact, the logical methods of our empirical language game has no bearing on it as it is an altogether different game with different rules so it has a different 'logic' of its own. Some people have criticised Wittgenstein of Fideism - of vindicating an anti-rational faith. I disagree. Different games can be criticised, it's just that we now have to criticise them on different terms rather than logical. When we criticise something on logical terms we are saying that someone has broken the rules of the empirical language game. When we criticise a religious language game we are saying that the rules themselves suck. So we are condemning the practice as a whole on practical terms. Criticisms (and defenses) of moderate religion can only be on pragmatic terms.
It's not a simple cut and dry distinction between moderatism and fundamentalism.
Moderates will often have a fair few beliefs about the real world based on their religion and fundamentalists will have their fair share of mysticism but the difference is where the driving force is. A fundy will say that if Christ did not really rise then their faith is for nothing. A moderate will be open to the possibility that it did not happen and declare that it's not really relevent to their faith.
So where am I going with all of this?
The Rational Response that we give to fundamentalists is not so persuasive towards moderates. A good example is one of our residents losingstreak. Anyone who has debated with losingstreak will notice that he argues rationally but says that the atheistic results of rationality are unimportant to him. The excessive adherence to the empirical language game doesn't appeal to him and he'd much rather experience life through the rules of a different game. Christian scientists seem to be similar - they'll play the empirical language game with a rare mastery when finding groundbreaking research in neuroscience but leave it in the office and prefer to play a different game when dealing with other parts of their life. (Like Goulds' NOMA?)
It also explains the disgust some people can have when we demand scientific evidence for their beliefs. It means that we are demanding that they play the language game of empirical facts. This is why they respond by finding other things outside the empirical language game, like morals or arts/aesthetics, and accusing us of having no 'soul' or emotion. Wittgenstein suspected that much confusion was caused by confusing different language games and equivocating words that different uses in different language games. Recognising this would allow us to communicate our scepticism to believers more effectively. We would get a better idea of how to ask the right questions.