Internal Evidence Test
Like good detectives, historians verify reliability by looking at internal clues. Such clues reveal motives of the authors and their willingness to disclose details and other features that could be verified. The key internal clues these scholars use to test for reliability are the following:
- consistency of eyewitness reports
- details of names, places, and events
- letters to individuals or small groups
- features embarrassing to the authors
- the presence of irrelevant or counterproductive material
- lack of relevant material
Let’s take as an example the movie Friday Night Lights. It purports to be based on historical events, but like so many movies loosely based on actual events, it leaves you constantly questioning, “Did things really happen that way?” So, how would you determine its historical reliability?
One clue would be the presence of irrelevant material. Let’s say that in the middle of the film the coach, for no apparent reason, gets a phone call informing him that his mother has brain cancer. The event has nothing to do with the plot and is never mentioned again. The only explanation for the presence of this irrelevant fact would be that it actually happened and that the director had a desire to be historically accurate.
Another example, same movie. Following the flow of the drama, we want the Permian Panthers to win the state championship. But they don’t. This feels counterproductive to the drama, and immediately we know it’s there because in real life Permian lost the game. The presence of counterproductive material is also a clue to historical accuracy.
Finally, the use of actual towns and familiar landmarks such as the Houston Astrodome leads us to take as history those elements of the story, because they’re too easy to corroborate or falsify.
These are but a few examples of how internal evidence leads either toward or away from the conclusion that a document is historically reliable. We’ll look briefly at the internal evidence for the historicity of the New Testament.