The image is going around, sometimes without attribution. The source and a quote that is meaningful to me.
Image Source: By Rocket000 [Public domain], via Wikimedia Commons: Graham's Hierarchy of Disagreement. As always, you can click on the image to see a larger version of the image.
This is the passage that stuck with me from this first time I read Graham's essay.
But the greatest benefit of disagreeing well is not just that it will make conversations better, but that it will make the people who have them happier. If you study conversations, you find there is a lot more meanness down in DH1 than up in DH6. You don't have to be mean when you have a real point to make. In fact, you don't want to. If you have something real to say, being mean just gets in the way.
If moving up the disagreement hierarchy makes people less mean, that will make most of them happier. Most people don't really enjoy being mean; they do it because they can't help it.
Paul Graham, How to Disagree, March 2008