I find this is the most constructive way to resolve a debate between two people (see: http://lesswrong.com/lw/881/the_pleasures_of_rationality/) But in long-running debates, or ones with heated debaters, this is much harder. Firstly, because many debates are long running precisely because this strategy cannot be applied to the,. The issue with heated debaters is that this requires an open mindset of looking for truth versus looking to prove yourself right, which I find lacking in many debates.