Dialectic. From the Greek dialektos (discourse or debate). In the classic form in which dialectic is used by Plato, it is the science of drawing rigorous distinctions. Aristotle preferred demonstration from first principles, but he recognized dialectic as a method of criticism. Throughout the Middle Ages dialectic was treated as in partnership with logic and listed as one of the three disciplines that constituted the trivium in the medieval educational system. (See Liberal Arts, The Seven and Quadrivium.) From the same Greek root comes the word "dialogue", which is used to describe the literary form in which Plato wrote his earlier works and which exhibits what is nowadays commonly called the Socratic method: a way of philosophizing through discussion between two or among more than two parties.

Geddes MacGregor, Dictionary of Religion and Philosophy, New York: Paragon House, 1989