Mercier and Sperber argue that, when you look at research that studies people in the appropriate settings, we turn out to be in fact quite good at reasoning when we are in the process of arguing; specifically, we demonstrate skill at producing arguments and at evaluating others' arguments.

I observed some time ago that Roger Penrose seemed to be a much better explainer of physics when he was using it to argue something (even though the conclusion was completely bogus) than people who graciously write textbooks that will be required reading for the students who have to buy it.

If you want good textbooks, make sure the author is trying to persuade the students of something, I'd say. I usually am.