At least once, I have done the following: "Here's why I disagree with your position. [supply a concise statement]. I'm done with the conversation here, but I

At least once, I have done the following: "Here's why I disagree with your position. [supply a concise statement]. I'm done with the conversation here, but I'll let you have the last word." It conveys disagreement. It conveys that I'm out. But it's still respectful.