Barth gets a bad rap as a man who airs theological grievances in public, and perhaps Nein! has something to do with it, but to read his correspondence, it is truly remarkable the lengths to which he goes to present common fronts in public with scholars with whose work he disagrees. Barth prefers his theological wrangling to occur in private, where a nosy world can't see it and use it for leverage. At least in the early period, he and Thurneysen start out trying to learn what can be learned from someone, before judging the disagreements. I continue to be amazed at how Luther's 8th this all is.