Dialectic: A process of thinking or argument that involves contradictions and their resolution, sometimes in the form of questions and opposing answers. The term has been used very differently by different philosophers. Plato thought of dialectic as the highest form of reasoning. Aristotle and later medieval philosophers tended to think of dialectic as a formal method of disputation. Immanuel Kant developed a "transcendental dialectic" that attempted to reveal the contradictions into which uncritical reason falls. G. W. F. Hegel developed a dialectical logic, which he saw as providing the formal structure of history as well, seen as the progressive unfolding of the Absolute. This historical dialectic was taken over by Karl Marx and put to use in his dialectical materialism.1
1. C.Stephen Evans, Pocket Dictionary of Apologetics & Philosophy of Religion (Downers Grove, IL: InterVarsity Press, 2002), p. 35.