Marshall McLuhan and Harold Innis offered important insights into the historical impact of communication technologies on modes of thinking, perceiving and behaving, and on their social and cultural effects. For both men, changes in technology drive historical change and construct reality. Technologies of communication are central to Innis's writing of history; they mediate the rise and fall of monopolies of power and shape the interactions of knowledge and control within society. Paul Heyer argues that Innis's concern with the influence that forms of communication can exert over content could be seen "as a less flamboyant precursor to McLuhan's legendary phrase 'the medium is the message.'" 24
McLuhan takes Innis's concept of time- and space-bias and creates the suggestive terms time-binding and space-binding, which relate not to media but to knowledge and power. While both scholars believed media were biased, their arguments diverge in other areas. For instance, in The Bias of Communication, Innis reflects on the oral tradition: "A decline of the oral tradition meant an emphasis on writing (and hence on the eye rather than the ear) and on visual arts, architecture, sculpture, and painting (and hence on space rather than time)." 25 The central part of Innis's argument is about space and time, though he also mentions the eye and ear. James Carey has argued that McLuhan has taken this minor part of Innis's work and built his theories around the effects media have on our senses. McLuhan takes the point further by saying that technologies are extensions of thought, of consciousness, and therefore of the mind. In doing so, McLuhan is more focused on the individual as an agent in society than on society as a whole.
McLuhan asserts that history has unfolded in technological epochs: orality, phonetic alphabet and script culture, movable type and, now, electronic technologies, beginning with the telegraph. Although these followed one another, they are not teleological. Each new epoch or development in communications media forces us to confront what came before; we retrieve old practices and cultures, even while we advance or enhance new ones. McLuhan's understanding of oral culture also differed from Innis's in a significant way. While Innis valued the discussion and debate emphasized in the oral cultures of ancient Greece, McLuhan favoured the predominantly oral cultures of the Middle Ages, which were rooted in chant and memory. 26
McLuhan had a very broad concept of media, since he believed that they were extensions of the body. Since all artefacts extend some element of the body -- whether it be thoughts (through language), or feet (through the wheel) -- they all mediate human relations and thus perform a communicative function; all artefacts are communications media. 27 Technologies, in this sense, are ways of encoding reality. How reality is encoded, in turn, affects cultural forms, societal structures and the way in which knowledge is internalized. 28 Indeed, McLuhan understood media as working like language, with internal structures and rules, or grammars. An examination of these grammatical structures, however, requires a deeply historical approach, since they are made up of previous technologies and previous grammars.
24. Heyer, Harold Innis, p. 61.
25. Innis, The Bias of Communication, p. 130-131.
26. Carey, "Marshall McLuhan: Genealogy and Legacy."
27. Babe, Canadian Communication Thought: Ten Foundational Writers,p. 26.
28. Marchessault, Marshall McLuhan, Cosmic Media, p. 120.