I liked this post. One thing I'd like to add is that you encourage rationality, in yourself and others, when you don't make disagreements adversarial.

If you want to know what a non-adversarial disagreement looks like, check out Bloggingheads. It's two bloggers, every day or so, having a discussion about current issues, and they never rant -- they always maintain friendly collegiality. I've always admired that.