McLuhan, Marshall. “The Medium is the Message.” From Durham, Meenakshi Gigi, and Douglas Kellner. Media and Cultural Studies: Keyworks. Malden, Mass: Blackwell Publishers, 2001, 107-117.
McLuhan addresses the focus of media critics on the content of new technology (TV, radio, film) rather than the effect and nature of these new, faster mediums themselves. The medium itself effects the society in which it exists to an even greater degree than the content it carries.
McLuhan uses the light bulb as a basic example. It does not have content, but changes society anyway by creating space in the dark. Similarly, a story about a heinous murder has less an effect on society due to the specific story itself then the fact that such a story will change attitudes and perceptions in society.
While I can see why McLuhan was considered a key scholar at the time, this essay feels a bit dated. I think post-modern media scholars (such as Jason Mittel in "A Cultural Approach to Television Genre Theory") have managed to heed McLuhan's advice and consider the nature of the medium itself, while simultaneously discussing content. While he makes important points about the power of the medium itself, I find his theories and argument rather elusive and tenuous.