Fundamentalism is an interpretive strategy. Fundamentalism is not a divine command; it is a human decision about how to read a text, and it should be made to prove itself against all of the other equally human approaches to reading. No one has a magical hermeneutic key descended from Heaven, and there is no reason whatsoever to believe from the outset that fundamentalist readings are any closer to God than any other. The fundamentalist interprets his text just like anyone else does. The only difference is that he claims not to interpret, and the sacredness of the text causes many people to believe what would in any other context be an obvious imposture.
It is tempting to claim that a literal interpretation is somehow the most 'natural', or the 'default' option. But I think this is simply because it comes most easily to us literal-minded folk. Some past cultures were, I gather, not nearly so literal-minded. I vaguely recall reading an ancient Roman historical text, calmly relating the role that the gods and sea monsters played in the day's events. Even if my memory misleads me, we can certainly imagine a culture where their talk is infused with mythological references, which have more poetic than literal significance. (They may treat religion as a cultural practice, rather than a collection of metaphysical beliefs, and so be puzzled if an outsider were to ask them if they thought it was "really true?" They didn't take themselves to be making such assertions.)
The point is this: given our cultural background, we tend to automatically interpret text literally. (There are some exceptions, e.g. idiomatic expressions.) It may not even occur to us to interpret it any other way - or if it does, it may seem forced or artificial. But this is a wholly contingent fact about us. We could have been different. In the imagined culture, one automatically interprets text poetically. It may not even occur to them to interpret it any other way. No more than we are tempted to think that a man needs a wheelchair upon making a purchase that "cost him an arm and a leg."
Does that sound right? I've heard of similar views in aesthetics, i.e. that there is no natural distinction between "realistic" vs. "abstract" art or representation. There are only signs that are more or less conventionally familiar. The more familiar ones are recognized automatically, and so no conscious interpretive effort is required, which misleads us into thinking that there is no interpretation involved at all. Contingent ease is thus mistaken for essential naturalness. There's surely something right about this, though the leap to full-blown interpretive relativism seems a bit suspicious. Any thoughts?