In social/theological discussions, the true dialogue has to happen between extremes. It's the same with philosophy, politics, science, indeed everything where arguments are made and conclusions are drawn. Both extremes have ways of cutting off dialogue and ending the conversation by exploiting their power. In any healthy dialogue there's a level of vulnerability that all parties must embrace. When we try to avoid that vulnerability, we resort to efforts to control the conversation and we fall to extremes. We have to accept some lack of control and some humble "uncertainty" in order to keep the conversation alive so that common ground can be discovered and fresh conclusions can be drawn.
In theological conversations I've noticed that both "liberals" and "conservatives" have key phrases to which they turn when they resort to extremes and try to control the conversations. For liberals, they need only to utter the words, "it's a justice issue." Justice is the unquestionable fundamental for such a perspective. Conservatives, on the other hand, need only say "the Bible is very clear about..." Scripture is the unquestionable fundamental for such a perspective. Both of these phrases can cut the conversation off and end the potential for dialogue to reach any real shared conclusion. We have to allow for even our "unquestionables" to be questioned if we really want to engage in healthy dialogue. If we really believe that community is important, if we really think that our conversations are worth having, then we need to create space in which to share perspectives and engage in authentic discourse between extremes.