The concept that the expressive form of a work of art is its true “message,” quite independent from its representational content, has been the mainstay of aesthetic theory since the beginning of the twentieth century. McLuhan’s familiarity with this concept, derived from his background in literary criticism, may be seen as one of the stimuli behind some of the ideas proposed in Understanding Media and may also help to explain the intuitive appeal of the phrase “the medium is the message.”

Furthermore, some of the other themes used by McLuhan in his theory of communication are also derived from works which had already received considerable attention by the time of his writing. In particular, one must remember that two American anthropologists, Edward Sapir in the 1920’s and Benjamin Lee Whorf in the 1950’s, had developed a theory of linguistic relativity which proposes that a culture’s language determines that culture’s overall worldview. Also, as early as the 1930’s, a full-blown theory of technological determinism was developed by the influential Chicago school of sociology. Writing in 1940, Robert Ezra Park summarized this theory by saying, “Technological devices have naturally changed men’s habits and in doing so, they have necessarily modified the structure and functions of society,” an idea not unlike the one McLuhan was to present in his own work.

Yet the phenomenal popular success of Understanding Media and the greater critical attention attracted by McLuhan can only be understood in the context of the special intellectual and social atmosphere of the 1960’s. By 1965, when the McLuhan phenomenon was in the limelight, the unusual characteristics of this decade had become apparent. People felt as if they were living through a nodal moment in history, and that caused both excitement and bewilderment. As a consequence, and as it often happens during periods of major social change, people looked for prophets, wise persons who provide explanations for changes and offer predictions for the future. McLuhan was easily identified as one of these prophets on the basis of his theories; the messianic fervor of his tone, the immediacy of his literary style, and the insouciance of his personality combined to make him a popular icon.

In a way, the success of Understanding Media proved to be the undoing of McLuhan’s theories. By the beginning of the 1970’s, his ideas had been either completely assimilated or totally rejected, and the works in which they had been presented were receiving less and less attention—but then, the progressive obsolescence of the printed word (and of the belief in linear theories of causality) is one of the predictions McLuhan himself had made.