Some philosophical phrases survive because they sound paradoxical. "The medium is the message" is one of the best examples. At first hearing, it sounds wrong. Surely the message is the message. Surely what matters is the content being communicated, whether that content is a news story, a political speech, a novel, or a television show. But Marshall McLuhan's point was that people focus so heavily on content that they miss something larger and often more powerful. The form through which content is delivered changes human behavior, social structure, and perception in ways that may matter more than any individual piece of content itself.