When an open-minded person and closed one approach a topic together, one will consider multiple sides while the other will dismiss anything that doesn’t strengthen their initial opinion.
That means the open-minded person divides their effort across multiple arguments while the closed-minded person focuses on their own.
Overall, the majority of their combined efforts are devoted to one side, while only a fraction of one person’s effort represents the rest—The overall discussion would be biased toward the closed-minded person’s point of view.
A closed-minded person is inflexible by definition, so they can’t be relied on to bend for the sake of neutrality.
Should open-minded people use single-minded arguments to maintain balanced discourse? Otherwise, even with the best of open-minded intentions, the discussion would always bias to one side.