Dialectic (also dialectics and the dialectical method) is a method of argument for resolving disagreement that has been central to European and Indian philosophy since antiquity. The word dialectic originated in ancient Greece, and was made popular by Plato in the Socratic dialogues. The dialectical method is discourse between two or more people holding different points of view about a subject, who wish to establish the truth of the matter guided by reasoned arguments.

The term dialectics is not synonymous with the term debate. While in theory debaters are not necessarily emotionally invested in their point of view, in practice debaters frequently display an emotional commitment that may cloud rational judgement. Debates are won through a combination of persuading the opponent; proving one's argument correct; or proving the opponent's argument incorrect. Debates do not necessarily require promptly identifying a clear winner or loser; however clear winners are frequently determined by either a judge, jury, or by group consensus. The term dialectics is also not synonymous with the term rhetoric, a method or art of discourse that seeks to persuade, inform, or motivate an audience. Concepts, like "logos" or rational appeal, "pathos" or emotional appeal, and "ethos" or ethical appeal, are intentionally used by rhetoricians to persuade an audience.

The Sophists taught aretē as the highest value, and the determinant of one's actions in life. The Sophists taught artistic quality in oratory (motivation via speech) as a manner of demonstrating one's aretē. Oratory was taught as an art form, used to please and to influence other people via excellent speech; nonetheless, the Sophists taught the pupil to seek aretē in all endeavours, not solely in oratory.

Socrates favoured truth as the highest value, proposing that it could be discovered through reason and logic in discussion: ergo, dialectic. Socrates valued rationality (appealing to logic, not emotion) as the proper means for persuasion, the discovery of truth, and the determinant for one's actions. To Socrates, truth, not aretē, was the greater good, and each person should, above all else, seek truth to guide one's life. Therefore, Socrates opposed the Sophists and their teaching of rhetoric as art and as emotional oratory requiring neither logic nor proof. Different forms of dialectical reasoning have emerged throughout history from the Indosphere (Greater India) and the West (Europe). These forms include the Socratic method, Hindu, Buddhist, Medieval, Hegelian dialectics, Marxist, Talmudic, and Neo-orthodoxy.