Advertising: the science of arresting the human intelligence long enough to get money from it.

Stephen Leacock (1869–1944), a Canadian economist and one of the early 20th century’s best-known humorists, frequently satirized modern commercial life—especially the growing power of mass marketing in newspapers, magazines, and department-store culture. The quip about advertising reflects the period’s rapid professionalization of advertising as a “science” of persuasion, complete with copywriting formulas and psychological appeals. Leacock’s humor often targets the mismatch between lofty language and blunt motives; here he punctures the self-importance of the advertising industry by reducing its “scientific” aim to a momentary capture of attention for profit.

Leacock’s definition is a compact satire of persuasion in a market society. By calling advertising a “science,” he mimics the industry’s claim to expertise, then undercuts it with “arresting the human intelligence,” implying that ads succeed not by informing reason but by interrupting it—seizing attention before critical judgment can fully engage. The final clause, “to get money from it,” strips away any pretense of public service and frames advertising as a transaction engineered through distraction. The line remains resonant because it anticipates modern concerns about attention economics: the commodification of focus and the strategic bypassing of deliberation.