Marshall McLuhan, his importance lies in something surprisingly simple: he argued that the medium through which information travels can change society as profoundly as the information itself.

Marshall McLuhan's most important contributions

1. “The medium is the message.”
This is McLuhan's most famous idea. He meant that when a new technology appears, its deepest effects aren't necessarily the particular things it communicates. The technology itself changes how we perceive, think, interact, and organize society.

Television, for example, wasn't merely a new way of transmitting programs. It altered attention, politics, family life, advertising and the relationship between viewer and event.

2. He taught us to study technology as an environment.
McLuhan thought we tend to notice content but overlook the technological environment carrying it.

A fish doesn't notice water. Similarly, people living inside a technological system may not notice how profoundly it is shaping them.

That insight is particularly powerful in the age of smartphones and AI.

3. He anticipated the Internet.
Long before the Internet existed, McLuhan described the possibility of an “electronic global village.” Electronic communications, he argued, would make distant events immediately present to people everywhere and would increasingly connect human beings into a single communications environment.

He wasn't predicting the Internet in its modern technical form. But the social phenomenon he described is remarkably recognizable in social media, streaming, video calls and instantaneous global news.

4. He distinguished “hot” and “cool” media.
McLuhan proposed that different media demand different degrees of participation from their audiences.

A photograph, for instance, supplies a great deal of visual information; a telephone conversation leaves much more for the participant to construct. His terminology is not universally accepted today, but the underlying question remains useful:

How much does a medium make us participate, and how much does it do for us?

That question has become especially interesting with interactive media, gaming and AI.

5. He understood that media change the structure of attention.
McLuhan wasn't simply interested in whether people received more information. He was interested in what happens when the speed, quantity and form of information change.

That makes him highly relevant to today's problems of:

Why McLuhan still resonates

The extraordinary thing about McLuhan is that AI makes his central insight newly important.

Consider ChatGPT. One can ask, “Is this answer correct?” But McLuhan would probably encourage a larger question:

What happens to human thinking when people routinely have a machine between themselves and the act of composing, researching, remembering and reasoning?

That is a very McLuhan-like question.

Likewise, social media isn't simply a collection of messages. Its speed, algorithms, notifications, visual structure and feedback mechanisms encourage particular kinds of behavior. The medium influences what gets noticed and what gets ignored.

His most enduring lesson

McLuhan's deepest contribution wasn't a prediction about any particular technology. It was a method of questioning technology.

Instead of asking only:

“What does this technology allow us to do?”

he taught us to ask:

“What is this technology doing to us?”

That is why his work continues to resonate. Television made his ideas important; the Internet made them prophetic; AI may make them unavoidable.

His two books to start with are Understanding Media (1964) and The Gutenberg Galaxy (1962). Understanding Media is probably the best place to begin if you're interested in his relevance to the present.

If you want, I can: