He had a thing for clip-on neckties. He once said LSD was the lazy man's form of Finnegans Wake. When deciding whether a book was worth reading, he'd flip through its table of contents then skip ahead to page 69. If page 69 offered no insight, he'd put the book down and move onto the next. In a 1951 letter to Ezra Pound, he described himself as an "intellectual thug."

That man was eclectic Canadian media theorist Marshall McLuhan, who lived from 1911 to the very last day of 1980, the same year CNN launched. This year, however, marks the 50th anniversary of his famous work, Understanding Media: The Extensions of Man, which builds upon his famous aphorism: "The medium is the message." Last April, the Journal of Visual Culture devoted an entire issue to exploring Understanding Media's enduring influence. Article titles include "I Sing the Senses Electric," "Reading for the Noise," and "Terrorphone."

Along with the success of his 1962 book The Gutenberg Galaxy, which describes how changes in communication technologies (e.g. the printing press) fundamentally alter people's orientation to the world, Understanding Media propelled McLuhan into the realm of pop-culture priesthood. He appeared on The Dick Cavett Show and the cover of Newsweek. Executives from General Electric and IBM arranged private meetings. In the New York Herald Tribune, Tom Wolfe wondered if McLuhan was the most important thinker since Newton, Darwin, Freud, and Einstein. A 1965 piece in Harper's, titled "Marshall McLuhan: Canada's Intellectual Comet," states, "like it or not, he is on his way to becoming one of those annoying 'seminal' thinkers whose arguments you must adapt, incorporate, or dispose of before pressing ahead in his field or—as McLuhan clearly believes—into areas well beyond it."

Still, McLuhan had his detractors. The critic Dwight MacDonald called his work "impure nonsense, nonsense adulterated by sense." Time described Understanding Media as "fuzzy-minded, lacking in perspective, low in definition and data, redundant, and contemptuous of logical sequence." In the late '70s, only six students enrolled in McLuhan's once prominent seminar at the University of Toronto, where he spent many years teaching. According to one witness, cardboard boxes filled with unsold copies of McLuhan's books littered the classroom.

"People who don't like McLuhan in the academic world are either lazy, stupid, jealous, or some combination."

TWENTY YEARS AGO, IN the introduction to a re-print of Understanding Media, renowned editor Lewis H. Lapham wrote that much of what McLuhan had to say made a lot more sense in 1994 than it did in 1964, what with two terms of Reagan and the creation of MTV. Twenty years after that, the banality of McLuhan's ideas have solidified their merit. When Yahoo! CEO Marissa Mayer, for example, compared the expansion of big data to the planet developing a central nervous system, that's McLuhan. When Chief Justice John Roberts opined that an alien from Mars might mistake the smartphone as an integral feature of human anatomy, that's McLuhan, too. In 2014, it's hard to overstate McLuhan's prescience.

"People who don't like McLuhan in the academic world are either lazy, stupid, jealous, or some combination," says Paul Levinson, a professor of communication and media studies at Fordham University, where McLuhan taught for a year in the late '60s. "McLuhan wasn't into commonsense, reasonable propositions. He liked looking at things in a poetic, metaphoric way."

And it's true: McLuhan had a penchant for speaking in riddles and rhymes that might baffle at first, but grow into epiphany if given the chance. His rhetorical style was hyperbole. He didn't shy away from playing the holy fool, as Wired would later call him, and on a number of occasions claimed his mission was simply to probe the new terrain, not come back to camp with answers. One time when a critic rebuked him, McLuhan responded by saying, "You don't like those ideas? I got others." A colleague once said McLuhan was "never intimidated by facts."

For those in the dark, what McLuhan had to say goes something like this: Way back when, humans communicated orally. Ears and mouths were key in an environment dominated by sound. With the invention of the alphabet and written words, sight became the paramount sense. Reading was also linear, logical, and done in solitude, which led to the individualization of both people and nations. Then came electronic media: telegraphs, telephones, televisions. These devices, in their ability to traverse both time and space, re-tribalized society. McLuhan deemed this new predicament the Global Village. "The world is now like a continually sounding tribal drum where everybody gets the message all of the time," McLuhan said during an interview in 1960. "A princess gets married in England and boom, boom, boom go the drums. We all hear about it. An earthquake in North Africa, a Hollywood star gets drunk—away go the drums again." But the content of the message isn't what matters; what matters is the medium, because it is the medium that modifies our senses when processing the received information. McLuhan's implications are radical, and certainly beyond any anxieties over the etiquette involved in adopting new technologies.

SO WHAT ELSE CAN McLuhan teach us about today's media-saturated reality? Alex Kuskis, an adjunct professor at Gonzaga University and the editor of the McLuhan Galaxy, the McLuhan Estate's official blog, suggests looking at chapter four of Understanding Media. Title: "The Gadget Lover: Narcissus as Narcosis." In it, McLuhan outlines how the myth of Narcissus staring at his own reflection in the water is much like us staring at a version of ourselves in our own devices, yet we don't always recognize it as such. Tablets definitely come to mind here, but so do selfies and social networks. If we're not vigilant, this can lead to a sense of oblivious numbness. In an interview with Playboy, McLuhan elaborates on this idea:

All media, from the phonetic alphabet to the computer, are extensions of man that cause deep and lasting changes in him and transform his environment. Such an extension is an intensification, an amplification of an organ, sense or function, and whenever it takes place, the central nervous system appears to institute a self-protective numbing of the affected area, insulating and anesthetizing it from conscious awareness of what's happening to it. It's a process rather like that which occurs to the body under shock or stress conditions, or to the mind in line with the Freudian concept of repression. I call this peculiar form of self-hypnosis Narcissus narcosis, a syndrome whereby man remains as unaware of the psychic and social effects of his new technology as a fish of the water it swims in. As a result, precisely at the point where a new media-induced environment becomes all pervasive and transmogrifies our sensory balance, it also becomes invisible.

Today, of course, the water we swim in is an ocean of information and perpetual connectivity to almost anyone anywhere. To newborns, the latest iPhone will appear just as natural as a pair of glasses or sneakers. In a lecture on McLuhan's legacy delivered in 1999 at Fordham University, Tom Wolfe stated that McLuhan considered the gap between generations as neurological, not ideological. Children raised on television were simply wired differently than their parents. For the last generation to experience life without the Internet, things are about to change yet again.

Although a huge admirer of McLuhan, Levinson believes he went too far with his media determinism. In chapter four of Understanding Media, McLuhan wrote that humans are "the sex organs of the machine world," comparable to the "bee of the plant world, enabling it to fecundate and to evolve ever new forms." In this scenario, technology dominates us more than we dominate it, leaving little room for freewill or the power to power down. Levinson doesn't agree.

"This isn't the first time a new medium was introduced," says Levinson, who believes any transition period involving new media necessitates growing pains, but the human species has survived all such transitions before. Facebook is not something to fear.

As for the ethics of all this, McLuhan largely remained silent. In a debate with Norman Mailer, Mailer complained that in McLuhan's work, "you never find the words good or bad." In response, McLuhan quoted Edmund Burke: "I do not know how to draw up an indictment against a whole people."

"He came to a point where he realized that it was really self-defeating to be moralistic about things that are not very well understood," Kuskis says. McLuhan felt the damning or praising of certain media impeded knowledge about their effect on the world. "I neither approve nor disapprove," said McLuhan during his interview with Playboy. "I merely try to understand."