Here was one of my favorite nuggets of wisdom from the Berkshire Hathaway Annual Meeting this year (which occurs at the 4:39:39 mark of the webcast). Munger has discussed these things many times before, but it is always good to review:
Charlie Munger: We try and avoid the worst anchoring effect which is always your previous conclusion. We really try and destroy our previous ideas.
Warren Buffett: Charlie says that if you disagree with somebody, you want to be able to state their case better than they can.
Charlie Munger: Absolutely.
Warren Buffett: And at that point you’ve earned the right to disagree with them.
Charlie Munger: Otherwise you should keep quiet. It would do wonders for our politics if everybody followed my system.