ABSTRACT
The reason why media affected culture so radically, Marshall McLuhan contended, was that the advent of a medium like print or television had the power to rebalance human ‘sense-ratios.’ This paper explores what he meant by such a puzzling assertion. To do so, it places his claim in the context of a ‘science of reading’ that had developed in the earlier twentieth century and become a ubiquitous element in North Americans’ educational experiences. Practitioners of this science used two kinds of instruments – eye-tracking devices and tachistoscopes – to analyze reading habits and train people to read both faster and better. In particular, an experimental psychologist named Samuel Renshaw adopted this science not only to train student readers, but to create a comprehensive practical science of sensory rebalancing. McLuhan learned about this practice and its intellectual ambitions when he visited Renshaw while drafting the first version of Understanding Media. Partly as a result, the sensory principles that scientists of reading believed to govern human creativity came to occupy a central part in his media theory of the 1960s.
