In general, a process of discursive knowing that weighs both sides of an argument in the attempt to discover truth. More specifically, in classical logic, that branch of material logic that uses common opinions and common principles to discover definitions and truths with a probable certainty.  The first comprehensive treatment of dialectical logic can be found in the Topics of Aristotle.  Subsequently, this branch of logic was developed in texts like Cicero’s De topicis differentiis and Topica, as well as in his rhetorical writings.  Boethius provided important commentaries on these works as well.  Often dialectical logic is associated with the stage of “discovery” or inventio.  In theology, such “topical” analysis would come to be used in methodological treatises such as De locis theologicis.