Mill’s Trident. The Trident holds that (a) if an opinion is true, silencing it robs us of truth; (b) if an opinion is partly true, silencing it deprives us of knowledge we lacked; and (c) if an opinion is false, silencing it still harms us because answering objections strengthens understanding.

Life is certainly much simpler when we agree with each other, but it’s also more prone to illusory thinking.