The electric light is pure information. It is a medium without a message, as it were, unless it is used to spell out some verbal ad or name. This fact, characteristic of all media, means that the \"content\" of any medium is always another medium. the content of writing is speech, just as the written word is the content of print, and print is the content of the telegraph.

...Whether the light is being used for brain surgery or night baseball is a matter of indifference. It could be argued that these activities are in some way the \"content\" of the electric light, since they could not exist without the electric light. This fact merely underlines the point that \"the medium is the message\" because it is the medium that shapes and controls the scale and form of human association and action. The content or uses of such media are as diverse as they are ineffectual in shaping the form of human association. Indeed, it is only too typical that the \"content\" of any medium blinds us to the character of the medium.

Each medium, like language itself, makes possible a unique mode of discourse by providing a new orientation for thought, for expression, for sensibility. Which, of course, is what McLuhan meant in saying the medium is the message. His aphorism, however, is in need of amendment because, as it stands, it may lead one to confuse a message with a metaphor. A message denotes a specific, concrete statement about the world. But the forms of our media, including the symbols through which they permit conversation, do not make such statements. They are rather like metaphors, working by unobtrusive but powerful implication to enforce their special definitions of reality. Whether we are experiencing the world through the lens of speech or the printed word or the television camera, our media-metaphors classify the world for us, sequence it, frame it, enlarge it, reduce it, color it, argue a case for what the world is like.