Locke prefaced his masterwork "Essay" with a rhetorically understated "Epistle to the Reader." In it he points to his awareness that the need for a systematic investigation of human understanding first arose in the context of a friendly, but unproductive discussion of other issues. Any intellectual has had this same thought as they attempt a dialog, whose goal is to reach an understanding, only to realize that people inherently percieve unequally. To have a productive discussion, agreements have to be made as to how arguments will be constructed, and what variables will be evaluated. At that point, truth most times magically appears without any more effort.