Dialectic is a formal system of reasoning that arrives at the truth through the exchange of logical arguments.
Dialectic is a process of examining an issue using very careful steps. A "thesis," or argument, is offered, followed by the "antithesis," or counterargument. The goal is to extract the best points from each of these to form a "synthesis." This in turn is used as a new argument, followed by counterargument, and the process continues, hopefully getting closer and closer to the truth, or at least something everyone can agree upon.