Source : Webster's Revised Unabridged Dictionary (1913)

Dialectics \Di`a*lec"tics\, n. [L. dialectica (sc. ars), Gr. ?
   (sc. ?): cf. F. dialectique.]
   That branch of logic which teaches the rules and modes of
   reasoning; the application of logical principles to
   discursive reasoning; the science or art of discriminating
   truth from error; logical discussion.

   Note: Dialectics was defined by Aristotle to be the method of
         arguing with probability on any given problem, and of
         defending a tenet without inconsistency. By Plato, it
         was used in the following senses:

   1. Discussion by dialogue as a method of scientific
      investigation.

   2. The method of investigating the truth by analysis.

   3. The science of ideas or of the nature and laws of being --
      higher metaphysics. By Kant, it was employed to signify
      the logic of appearances or illusions, whether these arise
      from accident or error, or from those necessary
      limitations which, according to this philosopher,
      originate in the constitution of the human intellect.

Source : WordNet®

dialectics
     n : a rationale for dialectical materialism based on change
         through the conflict of opposing forces