What does the Internet make of us?

All the people in this photo are using a mobile phone. These people are not the same as they were before those devices extended their minds and bodies in both the new digital world and the old physical one.

“We shape our tools and then our tools shape us,” wrote Father John Culkin, SJ, a Professor of Communication at Fordham and a colleague of Marshall McLuhan, whose magnum opus was Understanding Media: the Extensions of Man.

So: who — or what — are we, now that we are extended by, say, our phones?

Explained McLuhan, “All media are extensions of some human faculty — psychic or physical. The wheel is an extension of the foot.The book is an extension of the eye. Clothing, an extension of the skin. Electric curcuitry, an extension of the central nervous system. Media, by altering the environment, evoke in us unique ratios of sense perceptions. The extension of any one sense alters the way we think and act — the way we perceive the world. When these things change, men change.”

In The Medium is the Massage: an Inventory of Effects, he goes farther: “All media work us over completely. They are so pervasive… that they leave no part of us untouched unaffected, unaltered… Any understanding of social and cultural change is impossible without a knowledge of the way media work as environments.”

And he wasn’t just talking about communications media. He was talking about every thing we make, which then make us. As Eric McLuhan (Marshall’s son and collaborator) explains in Laws of Media: The New Science, “media” is “everything man[kind] makes and does, every procedure, every style, every artefact, every poem, song, painting, gimmick, gadget, theory — every product of human effort.”

Chief among the laws Marshall and Eric minted is the tetrad of media effects. (A tetrad is a group of four.) It says every medium, every technology, has effects that refract in four dimensions that also affect each other. Here’s a graphic representation of them:

The McLuhans apply these laws heuristically, through questions:

1. What does a medium enhance?
2. What does it obsolesce?
3. What does it retrieve that had been obsolesced earlier?
4. What does it reverse or flip into when pushed to its extreme (for example, by…