Jonathan Z. Smith has a provocative piece at the Chicago website for the Center for Teaching & Learning, called "The Necessary Lie: Duplicity in the Disciplines". Here are two excerpts:
We lie, it seems to me, in a number of ways. We sometimes cheerfully call the lie words like 'generalization' or 'simplification,' but that's not really what we're doing. We're really lying, and lying in a relatively deep fashion, when we consistently disguise, in our introductory courses, what is problematic about our work.
I think there is very little to justify introductory lying. In the case of the introductory courses, we produce incredibly mysterious objects because the students have not seen the legerdemain by which the object has appeared. The students sense that they are not in on the joke, that there is something that they don't get, so they reduce the experience to "Well, it's his or her opinion."
I realize that Smith's "lying" is a harsh term and he's doing it to be provocative. But maybe that's how we should regard our temptation to over-generalize and over-simplify in our teaching. Sometimes we're torn because sometimes the easiest examples we can use to make a profound point with our students aren't quite right and explaining them correctly loses the point we're trying to get across. What are we to do?
Let me give an example. It would really be pedagogically useful if Q (the hypothetical saying source that Matthew and Luke independently used) actually existed. Then we can start to get our students thinking about historical sources for Jesus that lay outside the canon. Q was never canonized but its contents are in the canonical Matthew and Luke. Thus, Q lies halfway between our canonical sources and non-canonical sources. Q's contents are not strange to our students but its structure and organization are. Indeed, Q promises a different way about early Christian thinking about Jesus, a way that was not relentlessly focused on the cross. But to make this point with intellectual integrity, we have to point out that the extent of Q isn't really known with much clarity (it could have had a passion for all we know) and even that are serious problems with its very existence. What are we to do?