Today marks the 100th birthday of the media theorist Marshall McLuhan, and while most of the centenary blurbs will note he coined "the medium is the message," his profound insight into communication theory is much better represented by his notion of the "unified sensorium."

For McLuhan, every technology was an extension of some aspect of humanity, from simple things like the wheel (as a foot) and the gun (as a fist). His insight, in his groundbreaking book Understanding Media, is that when we extend some part of ourselves, it creates an imbalance. And just as the wheel leads to the fractured physical world of cities and suburbs, the imbalances created by extensions of our higher faculties lead to mental and social dislocations.

We often forget — in the same way that fish are not aware of water — that writing is a technology. All human cultures have spoken language, but not all externalized that into a written representation. Many theorists have investigated the shift from oral to written culture, but few have envisioned the impacts as clearly as McLuhan.

In Understanding Media (pp. 88-90), he argues that the alphabet freed us from the "tribal trance of resonating word magic and the web of kinship" and through the power of letters as "agents of aggressive order and precision" gave us "empires and military bureaucracies" where individuals were alienated from their "imaginative, emotional and sense" lives.

The externalization of speech required humans to break down the natural flow of sound into discrete bits so we could inscribe it, and it is no accident that the alphabet is reflected in a clockwork world of interacting bits and pieces: mechanistic science, differential calculus, command-and-control hierarchies, assembly lines, and linear time.

If one reads McLuhan hopefully — and I always have — the digital revolution has the promise of extending the entire human mind as a technology. As the electronic world began to overtake print in the past hundred years, we have seen the breakdown of the profane and sequential. The atoms which persisted since Democritus' time are re-envisioned as 11-dimensional vibrating strings, ecology triumphed over taxonomy, manufacturing morphed into knowledge work, and the world, flattened by speed-of-light communication, became a global village.

McLuhan was not blind to the pain of change: he wrote an entire book, War and Peace in the Global Village, describing the spastic convulsions societies undergo during profound media transitions. (Effects anyone in journalism, publishing, or education these days understands all too well.)

But in the end, there remains the possibility that a the extension of consciousness itself through technology, a projection of the full sensorium in balance, could nudge us back toward a re-balanced psyche and society. And it is that thought that makes me celebrate the insights of this great thinker and teacher on his centenary.

Happy birthday, Marshall.