If I have someone else write my school essay for me, that is plagiarism.
Yes, but neither of us has made the argument that copy-pasting from AI should be allowed. All we're arguing is blanket prohibition vs. allowing assistance like research.
If the professor gives me feedback and lets me submit a revision, or if I use that feedback to improve future essays, that is not plagiarism. All my points against using AI in debates are specific cases of the principle that intentionally using human assistance specific to what you are writing is plagiarism
Is the professor giving feedback and letting you submit a revision not "specific to what you are writing"? Same with voters giving feedback on an argument. If I'm allowed to use feedback from a previous debate to make a stronger version of my argument, but my opponent who hasn't debated before isn't allowed to get feedback at all before they submit for this debate, then that's not really fair to them. I'll also note that in most courses, getting feedback from other students or a TA on an essay is allowed if not actively encouraged.
If I talked with someone about something years ago and mention that in my school essay, that is not plagiarism. If I ask someone to write a paragraph about that subject while I am writing my essay, tricking them into writing part of my essay for me, that is plagiarism.
Again, I'm talking about getting feedback, not having someone else write a paragraph for you. Analogy should be talking with someone about a subject and then implementing some of those ideas in your essay immediately while making it your own. It's possible to get ideas from ChatGPT and then make them your own, because it's all about implementation. Using AI doesn't have to mean having it write the argument for you.
Borrowing a concept is not plagiarism. Having a human or AI construct an argument for you from that concept is plagiarism.
So people should be allowed to use AI to ask for concepts. Like "what's a potential rebuttal to my argument?" Or "what are weak spots of this argument?" That's a concept, not something they are going to copy paste.