The 18th century brought a fundamental reconception of rhetoric. The Scottish and English belletrists who dominated the field — Hugh Blair, George Campbell, Richard Whately — inherited the classical tradition but rebuilt it on Enlightenment foundations: the empirical science of mind, the philosophy of taste and sentiment, and a new emphasis on written as well as spoken discourse. Enlightenment rhetoric produced the first modern rhetoric textbooks and shaped university writing instruction well into the 20th century.
The dominant 18th-century rhetorical tradition, centered at Scottish universities. Named for its emphasis on belles lettres — polite learning, including literature, criticism, and taste — alongside traditional rhetorical doctrine. Distinguished by its grounding in Enlightenment faculty psychology.
The Enlightenment Reconception of Audience
Classical rhetoric had centered on the civic orator addressing a public audience. Enlightenment rhetoric, responding to the rise of print culture and a new reading public, shifted its center of gravity toward written discourse addressed to a broader, more private audience. This shift had profound consequences for the discipline. If the audience is not a particular citizen jury in a specific courtroom but an indefinite reading public, the principles of audience adaptation become more abstract — and the psychological analysis of the reader's mind more central.
The Enlightenment's great contribution to this psychological analysis was faculty psychology — the view that the human mind comprises distinct faculties: understanding, imagination, memory, passions, and will. A complete rhetoric needed to address all of them. This framework, derived primarily from Locke and elaborated by Scottish philosophers, provided Enlightenment rhetoricians with a new systematic basis for the classical appeal to reason, emotion, and character.
George Campbell: Rhetoric and the Philosophy of Mind
George Campbell (1719–1796) wrote what is arguably the most philosophically sophisticated rhetoric of the 18th century. His Philosophy of Rhetoric (1776) opens with a definition that marks a clear break from the classical tradition: the end of all discourse is "to enlighten the understanding, to please the imagination, to move the passions, or to influence the will."
Campbell grounded rhetoric in Humean empiricism and the newly developed science of moral psychology. His treatment of evidence — distinguishing mathematical demonstration, deductive argument, testimony, analogy, and experience — brought logical rigor to rhetorical theory that Aristotle had not achieved. His analysis of the passions, drawing on Hutcheson and Hume, provided a systematic account of emotional appeal that went beyond classical doctrine.
Persuasion is not simply a matter of strong arguments. The orator must address the understanding, the imagination, the passions, and the will — in that order, since each must be properly prepared before the next can be engaged effectively.
— Adapted from The Philosophy of Rhetoric, Book IHugh Blair: Taste, Criticism, and Public Discourse
Hugh Blair (1718–1800) was the most widely read rhetorical author of the 18th century. His Lectures on Rhetoric and Belles Lettres (1783) — based on lectures delivered at the University of Edinburgh beginning in 1759 — went through over 130 editions by the mid-19th century and was adopted in universities across Britain and America.
Blair's approach was broader than Campbell's. He incorporated literary criticism, the analysis of taste, and the evaluation of style alongside traditional rhetorical doctrine. His lectures covered everything from the nature of taste and the theory of language to the criticism of particular authors and the principles of public speaking. This expansiveness made his work the founding document of what would become English and composition studies — but it also diluted rhetoric's systematic character, turning it toward criticism and away from the art of construction.
Richard Whately: Logic, Argument, and Presumption
Richard Whately (1787–1863) represents the third major direction of Enlightenment rhetoric: toward formal logic and argumentation theory. His Elements of Rhetoric (1828) argued that rhetoric should focus primarily on argumentative discourse — persuasion by reasoning — rather than on style, taste, or emotional appeal.
Whately's most lasting contribution is his analysis of presumption and burden of proof — concepts from legal practice that he applied to argumentation generally. His argument: in any dispute, there is a presumption in favor of the established position, and the burden of proof falls on whoever challenges it. This asymmetry is not a logical principle but a practical and epistemic one — it reflects the fact that we cannot demand positive justification for everything we believe, and that the challenger of established positions bears a special argumentative responsibility.
The Scottish Contribution: Ferguson, Kames, and Reid
Blair and Campbell were part of a broader Scottish Enlightenment project that placed rhetoric and communication theory at the center of a new science of human nature. Adam Ferguson's Essay on the History of Civil Society, Lord Kames's Elements of Criticism, and Thomas Reid's common-sense philosophy all contributed to the intellectual milieu that shaped belletristic rhetoric. Common-sense philosophy, in particular, provided a philosophical foundation for the assumption that audiences share basic perceptual and moral capacities — the assumption that makes rhetorical communication possible.
Key Enlightenment Texts
Current-Traditional Rhetoric: The Enlightenment's Ambiguous Legacy
The Enlightenment tradition eventually produced what historians of rhetoric call current-traditional rhetoric — the approach that dominated American composition instruction from roughly 1850 to 1970. Current-traditional rhetoric took Blair's emphasis on correctness and taste, Campbell's concern with psychological effects, and Whately's focus on argument and codified them into a formulaic pedagogy: five-paragraph essays, mechanically correct prose, the modes of discourse (narration, description, exposition, argument).
This pedagogy was enormously influential and enormously criticized. It preserved something of the rhetorical tradition's concern with effective communication but hollowed out its situational, audience-centered, civic character. The revolt against current-traditional rhetoric in the late 20th century — which produced process pedagogy, social epistemic rhetoric, and the new rhetoric — was in large part a revolt against the reductive consequences of the Enlightenment tradition.
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