Ads are the cave art of the twentieth century.

Marshall McLuhan (1911–1980), the Canadian media theorist best known for analyzing how communication technologies reshape perception and social life, often treated advertising as a defining “folk art” of modern mass media. The remark about ads as “cave art” fits his mid‑century preoccupation with television, print, and commercial imagery as the dominant environment in which twentieth‑century people lived and made meaning. In that period, advertising had become ubiquitous—on billboards, in magazines, on radio and TV—functioning not merely as salesmanship but as a shared visual language and a public record of desires, myths, and anxieties. McLuhan used such provocative analogies to jolt audiences into noticing media’s cultural role.

The comparison casts advertising as a society’s most characteristic visual expression—like prehistoric cave paintings, ads are public signs that encode communal values, fears, and aspirations. McLuhan’s point is less about artistic merit than about function: ads are a mass culture’s symbolic “wall,” where stories about identity, status, gender, progress, and happiness are repeatedly drawn and redrawn. The line also implies that modern people may be as immersed in commercial iconography as early humans were in ritual imagery, suggesting that advertising is not peripheral but central to how the twentieth century imagines itself. It is a critique and a diagnosis: ads reveal what the culture worships.