Argument by assertion is unanswerable. If, for instance, some vague waffle about an evolutionary transition does not satisfy a recalcitrant student, the instructor simply says, “This point should be intuitively obvious. I’ve explained it as clearly as I can. If you still cannot see it, you will just have to think very carefully about it yourself, and then you will see how trivial and obvious it is.” The instructor at this point might also want to add, “What are you, a creationist?” or “Are you one of those Christian fundamentalists?” or “Where have you been brainwashed?” Arguments by demonization like this are particularly effective when one or a few students get unruly, but the majority sides with the instructor.

Source: here.