Dialectic (Greek: διαλεκτική, dialektikḗ; German: Dialektik), also known as the dialectical method, refers originally to dialogue between people holding different points of view about a subject but wishing to arrive at the truth through reasoned argumentation. Dialectic resembles debate, but the concept excludes subjective elements such as emotional appeal and rhetoric. It has its origins in ancient philosophy and continued to be developed in the Middle Ages. In the modern period, Hegelianism refigured "dialectic" to no longer refer to a literal dialogue. Instead, the term takes on the specialized meaning of development by way of overcoming internal contradictions. Dialectical materialism, a theory advanced by Karl Marx and Friedrich Engels, adapted the Hegelian dialectic into a materialist theory of history. The legacy of Hegelian and Marxian dialectics has been criticized by philosophers such as Karl Popper and Mario Bunge, who considered it unscientific. Dialectic implies a developmental process and so does not naturally fit within classical logic. Nevertheless, some twentieth-century logicians have attempted to formalize it. Source: Wikipedia (en)