Written by McLuhan in 1955, the same year that the film Rebel Without a Cause was released.
Just two quotations from this longer essay:
"The American Revolution occurred just when the newspaper was sufficiently a reality to be changing and extending surface transport. The American Government was the first to be founded on the concept of public opinion. Such a concept still seems bizarre in Canada. It was the new medium not of the book but the press which shaped the U.S.A. and this creates a political crisis with the passing of the press into the entertainment limbo, and with the rise of TV as a political shaper. But it has also been the typical mistake of literate cultures to regard entertainment as non-political. Russia made no such slip."
"In Explorations 2 it was suggested that the new situation in the modern class-room is that the adolescent today does not need information. He is hopelessly overloaded with messages from the urban environment. The class-room no longer need typically perform the function of providing facts. It must above all provide techniques of recognition and discrimination. Reality-testing can no longer follow the linear, factual recital or statistical pattern. There is far too much reality for that. We are obliged to deal with reality in constellations and clusters or not at all. If politics and the citizen are to survive the new media, we must alter our entire sighting and range-finding apparatus, which is still oriented to the printed page alone."
Image is from The Medium Is the Massage, published in 1967
Via Jim Lerman