Over at WWA, Talisse and I have a short note on the difference between taking formal and dialectical perspectives on argument-assessment. For the NS readers, it’s a familiar distinction, but motivating it can be tricky. I’ve taken to using the intuitive notion of begging the question as a way of showing how an argument can be unquestionably valid but argumentatively out of bounds. (If the conclusion is one of the premises, the premises will of course guarantee the truth of the conclusion, by the PNC.) The consequence is that the development of a robust dialectical program for argument assessment is necessary — and, hey, that’s what’s been going down over here at the NS for years!