Oh, I absolutely agree to the need to talk about life-and-death issues when we disagree. I don't want to shut down these conversations, but I want the conversation to be in good faith, and for people to really listen to each other's points. In particular, if someone does get angry or otherwise emotional in tone, that shouldn't forfeit their opportunity to present their opinion and supporting facts (as long as they aren't aggressive or belligerent about it).

It's entirely possible that I miss-interpreted what the GP meant by "fighting words". My interpretation was "passionate argument" not "verbal abuse."