> In order to discover places where we currently are wrong, we need to be tolerant of people expressing dissenting points of view.

I agree, but I distinguish between tolerance & acceptance. Tolerance means you do your thing & I do my thing; acceptance means we do the same thing. The problem is, if we each have opposing ideas of the good then we can't accept one another's ideas. Acceptance of opposing ideas can only really work by pretending that the ideas themselves don't matter, but tolerance can respect the importance of the ideas themselves while agreeing to disagree.