Dialectic (also called dialectics or the dialectical method) is a method of argument, which has been central to both Eastern and Western philosophy since ancient times. The word "dialectic" originates in Ancient Greece, and was made popular by Plato's Socratic dialogues. Dialectic is rooted in the ordinary practice of a dialogue between two people, each of whom holds different ideas and wishes to persuade the other. The presupposition of a dialectical argument is that the participants share at least some meanings and principles of inference in common, even if they do not agree. Different forms of dialectical reason have emerged in the East and in the West, as well as during different eras of history (see below).

Among the major forms of dialectic reason are Hindu, Buddhist, Socratic, Medieval, Hegelian, Marxist, and Talmudic.