One way to deal with this issue might be to make it clear that the discussion proceeds conditional on the correctness of their position on the controversial thing. Either side could do this.
I think that only works if you say “even if that were true, which we don’t need to discuss now, I would argue that...”
It’s much harder to get someone to accept “for the sake of argument” something they strongly disagree with.
For example, I would only accept “morality comes from the Bible” if I had a convincing Bible quote to make my point.
Fair enough.
One way to deal with this issue might be to make it clear that the discussion proceeds conditional on the correctness of their position on the controversial thing. Either side could do this.
I think that only works if you say “even if that were true, which we don’t need to discuss now, I would argue that...” It’s much harder to get someone to accept “for the sake of argument” something they strongly disagree with.
For example, I would only accept “morality comes from the Bible” if I had a convincing Bible quote to make my point.