Civil discourse is engagement in discourse (conversation) intended to enhance understanding.
Overview
Kenneth J. Gergen describes civil discourse as "the language of dispassionate objectivity", and suggests that it requires respect of the other participants, such as the reader. It neither diminishes the other's moral worth, nor questions their good judgment; it avoids hostility, direct antagonism, or excessive persuasion; it requires modesty and an appreciation for the other participant's experiences.
In Book III of An Essay Concerning Human Understanding (1690), John Locke contrasts between civil and philosophical discourse (or rhetorical discourse) with the former being for the benefit of the reader, and the public good:
References
Civil discourse Wikipedia(Text) CC BY-SA