Lady Penelope's view is clearly reasonable, especially on questions like this one, where we've been over the ground pretty thoroughly. But I sometimes see that gesture used for hidden purposes in argumentation (which, in my field, is how we find things out as well as just plain fun). It may be used to avoid conceding defeat where there's a very important point of fact at stake (extreme example: holocaust deniers; doesn't apply here). Or it may cut off a discussion where the true/not true issue isn't going to be brought to conclusion, but a preponderance-of-evidence decision is possible. And argument of this type is how we learn rules of evidence anyway (Ong wrote that up until the twentieth century, advanced study in just about every subject consisted of arguing).


Adam