I was thinking about this on one forum I frequent. So many smart people, so much bickering. Why do they bicker? To show us all how clever they are, because they have low self-esteem because they live in a falling-apart society.
Our first impulse is to say:
Rule #1: Don't be a dick.
My problem with rules, however, is that they replace goals. Imagine this:
Goal: discuss the given subject matter in a way that makes it better.
This means: always aim toward being better than the last generation, which for discussion means knowing more, learning more, spreading good information.
By definition, bickering is excluded, because it's non-productive.
Sure beats having a rule where the bickerers will then say, "But I'm not bickering!" and attack using passive-aggressive means. "No, the other guy is the one bickering! I'm just telling the truth, for hope and change!"