For example, when discussing gender-related problems, it seems inevitable that some proposed solutions will generally be better for men, and other solutions will generally be better for women. If people are selfish, then they will each prefer the solution that's individually best for them, even if they can agree on all of the facts. (It's unclear whether people should be selfish, but it seems best to assume that most are, for practical purposes.)

But isn't it possible that in any given bargaining situation there may also be a win-win solution that makes the pie bigger and leaves everybody better off than the status quo? Discussion, debate, and further exchange of information could at least theoretically lead to a previously unrecognized win-win situation being found.