On teaching, by Rick Garlikov:
"Teachable moments arise at all kinds of times, sometimes induced by a teacher.
One common trick among those philosophy teachers who really want students to learn, is to give an "F" to students who turn in papers which argue that relativism is right or that everything is subjective, or mere opinion, etc. The students invariably come in to argue the unreasonableness and unfairness of the grade and show why they deserve not only to pass but to get an "A". The teacher will let them give all the arguments they want, and then will say something like "You realize, don't you, that you are totally contradicting the point you make in your paper, because you are offering me all kinds of objective and factual evidence for what you really believe is an objective truth -- that your paper deserves better than an "F". If you really believed the point of your paper, you would have to say that my giving you an "F" is as valid as your thinking it deserves and "A", and you would not be here arguing for the truth of your claim about the grade. Now I actually gave you a much higher grade than what I put on your paper because it is well-written, and well-argued, but it is simply wrong for reasons you did not consider, but which I hope you consider now, since you obviously do not really believe the conclusion you tried to establish. I only pretended to give you the "F" so that you would come in and argue exactly as you have."
These last two examples also relate to the issue of knowing what is interesting or significant or meaningful to students. My view of teaching is that it should not only be informative but, whenever possible, also inpirational so that students want to learn even more. When you have a "live" moment as in the above two cases, you already have the students' interest and attention and do not need to fish for something interesting to them to relate your material. In most cases, though, you need to spark some interest first, perhaps by stoking a debate among students over some issue they cannot resolve themselves or to present material in a way that students will likely find interesting, challenging, puzzling or somehow otherwise stimulating, perhaps even humorous. This again requires you to know both your material and students' likely interests."