Widely attributed to Marshall McLuhan but likely not of his invention. Used also by Andy Warhol and a frequently sounded slogan of the 1960s. The line appears in The Medium Is the Massage (1967), in large type, spread over several pages (132-136) without crediting any other source. It is also spoken in the audio LP, “The Medium Is the Massage” (1967), Side B, Transcript: 11:50.