I'm afraid I'm not good enough at graphics to get the diagram quite the way I wanted in the time limits of this morning. In theory, there might be a line right down the middle of the shaded area to make four basic interpretive approaches.
Broadly speaking, the two basic approaches are 1) an evidence-driven hermeneutic that tries to form its conclusions as much as possible on the basis of the evidence, following something like the scientific method and 2) a presupposition-driven hermeneutic that comes to the evidence with certain presuppositions that drive the limits of what can and cannot be concluded.
The overlap is an area where dialog can take place between those who take these contrasting approaches. It is an area where those who are primarily presupposition oriented can talk evidence and those who are evidence oriented fall within the presuppositional parameters of those who are more presuppositionally oriented.
Outside the overlap are the points where no discussion can take place and someone in the shaded area or other circle cannot dialog. For example, a person from the unshaded part of the evidence-driven hermeneutic might have a hard time approaching the text with a sense that miracles might take place or that God actually engages the world.
On the other hand, when a person is so presuppositional on an issue that no amount of evidence would bring a change of position, then a person approaching a topic from the standpoint of evidence will not be able to dialog with that person at all on that particular issue without ultimately discussing presuppositions.
It is impossible for anyone to be completely without presuppositions, and a presuppositionalist who does not engage evidence at some level will appear to be a lunatic. But this is why, on so many religious topics, we can't talk to each other. We should not be surprised.
