A blog post by Alistair Roberts, as curated by Steve Sailer. (Steve's version is shorter and more targeted; the original blog post is the fourth in a series on triggering and suffers for its reliance on the particular issue.)
It seems like a very useful dichotomy, and strongly reminds me of Ask and Guess.
This one of Paul Graham?
That's a pretty good one. Thanks.
But I think there was one with levels beyond "refutation of the central point". More of a "delimit and extend", where you show the bounds of validity of an argument, and what's true more generally beyond those bounds.