The tradition that treats persuasive public speech as a serious intellectual discipline — as a craft with its own principles, teachable and analysable, and as one of the essential vehicles of political life rather than a substitute for thinking.
The founding quarrel is between Plato and Aristotle and has never been settled. In the Gorgias Plato attacked rhetoric as flattery, a knack for producing conviction without knowledge, and therefore as the characteristic instrument of demagogues. Aristotle answered by making it a subject: his Rhetoric analyzes persuasion into ethos, pathos and logos, distinguishes deliberative, forensic and ceremonial speech, and treats the ability to see the available means of persuasion in any case as a rational capacity — a defense resting on the observation that truth does not argue itself and that leaving persuasion to the unscrupulous is not a neutral choice.
Rome made it the center of public education. Cicero's ideal of the orator-statesman fused eloquence with philosophy and civic virtue, and Quintilian defined the orator as the good man speaking well, embedding an ethical requirement in the technical definition. The Renaissance humanists recovered exactly this ideal, and the eighteenth-century parliamentary tradition — Burke, Fox, Sheridan — was its last great practical flowering.
Rhetoric was dismantled as a university subject over the nineteenth century and has been partly recovered in the twentieth, through Perelman's work on argumentation and through intellectual historians like Skinner who read political texts as rhetorical performances aimed at particular audiences. The Plato-Aristotle dispute meanwhile recurs in every argument about propaganda, advertising and social media: whether the answer to bad persuasion is less persuasion or better.