In philosophy, dialectic, is a method of arriving at conclusions by reasoning from commonly held, and usually contradictory opinions. The dialogues of Plato are the most famous early examples of the dialectic method at work. In them, Plato describes the attempts of Socrates to prove his philosophical theories by leading his opponents, through a series of questions and answers, to admit that their own opinions are self-contradictory and therefore false.
In the early 19th century the German philosopher G. W. F. Hegel used the word "dialectic" to stand for the scientific application of supposed universal laws of thought. He held that the dialectic is composed of three stages: the thesis, or original statement, or premise; the antithesis, or self-contradiction revealed through questioning the thesis; and the synthesis, or provisional conclusion, that results from the clash between the thesis and antithesis.
Hegel also said that in history the opposition between various political, social, economic, and cultural groups results in progress through a dialectical development. Hegel's views were adapted by Karl Marx in his philosophy of dialectical materialism.