I have this belief that humility is a part of good critical thinking, and that egoism undermines it. I imagine arrogance as a kind of mind-death. But I have no evidence, and no good mechanism by which it might be true. In fact, I know the belief is suspect because I know that I want it to be true — I want to be able to assure myself that this or that intolerable academic will be magically punished with a decreased capacity to do good work. The truth could be the opposite: maybe hubris breeds confidence, and confidence results? After all, some of the most important thinkers in history were insufferable.
Is any link, positive or negative, between arrogance and reasoning too tenuous to be worth entertaining? Is humility a pretty word or a valuable habit? I don't know what I think yet. Do you?
I'd say there are cases where it's reasonable to dismiss others' opinions out of hand (apart from politeness etc.) BUT it takes more than "I'm much smarter than them"; there should be a factor like "I have all the evidence they have / I know all they know on that topic" and of course "I have good reasons to believe I'm smarter than them and know more".
And even then it's the kind of thing that's reasonable "on average", i.e. it can be a decent time-saving heuristic if needed, but it can still get wrong. Say Alice is studying for a Masters degree in physics and Bob, a high-schooler who's not exceptionally bright (Alice had better science grades then him in high school), disagrees with her on something about black holes. As a rule of thumb, Alice is probably right BUT it happens that Bob just spent the summer camping with a family friend, Calvin, who's a physicist and just wouldn't shut up about black holes, explaining a bunch of concepts and controversies to Bob the best he could. Now it's pretty likely that Bob is actually right (though Alice might be justified in not listening anyway, depending on how good Bob is at explaining his position).
Yes, of course I agree. Domain expertise should also be included in your analysis.