Not very many know this, but McLuhan is an inherently funny author. Especially if you take him at his words and think in terms of media as the extension of man. Not only does this center the human being as the locus of analysis (if something extends something else, then the characteristics of this something else become of vital importance to understanding what is afoot) it also makes media a very bodily experience. Television is an extension of your eye, and allows you to see really far. A car is an extension of your legs, and allows you to run very fast. A book is an extension of your memory, and allows you to precisely recall things on demand. A house is an extension of your skin, and allows you to stay warm and cozy. Everything becomes very useful all of a sudden, and thinking about media this way centers just in what way it is useful. Depending on which bodily part it extends, its usefulness by necessity takes on different forms.
When McLuhan said that the medium is the message, what he meant was that because it extends your body, you necessarily form yourself around whatever the medium might be. Watching television means facing the set, often sitting down for extended periods of time. Driving a car means being in the car for the duration of the ride. Reading a book means entering into the complex negotiation between eyes, hands and various other body parts who struggle to make themselves relevant as the pages turn. And a house only works as a second skin for as long as you are in it; going outside means you’ve stopped engaging with it as a medium. Whatever is going on content-wise, your body contorts to suit the demands of the medium. This is, in the most direct of senses, the message.
Once you get into the habit of thinking of objects as media, and media as bodily extensions, it’s hard to get out of it. Sofas are extensions of our backsides, keyboards are extensions of fingers, flutes are extensions of our lips, – everything is an extension of something, and knowing the specific something of an object allows us to think about it in a clearer manner. if nothing else, it allows us to understand what we are doing all day. And, possibly, why we ache in places we’d seldom think of otherwise.
This only goes so far, however. Being centered around the human body is refreshing and all, but eventually you will run up against something that is not an extension of an individual human being, and the whole thing breaks down. Parliamentary democracy, for instance, does not extend any particular body part, in as much as it is a form of collective decision making. It is by definition a group of human bodies coming together, which is something else than extending any one of the individuals present. The whole is greater the sum of its parts. We can only run with it so far; eventually, other metaphors and ways of thinking will be necessary to complete the picture.
Having encountered a limit to the usefulness of a line of thought does not obviate said usefulness. As with everything else in life, it just means we have to use it in moderation, applying it when it might garner useful insights and picking up some other concept when it does not. A screwdriver does not a complete toolset make, but a toolset would do well to include at least one screwdriver.
This central limitation can spark our imagination in interesting directions, though. If there are things that are not extensions of the human body, then just what are they extensions of? What non-human entity is the intended user of these strange devices and artifices which have sprung into being? Are they friend, foe or utterly indifferent? How are we to think of these non-humans amongst us?
When gazing upon a great piece of machinery, far beyond any single human being in size and mechanical complexity, this is a humbling thought to have. And it is a thought that forces us to question just who it is for. If it works beyond human scale, without human intervention, along trajectories utterly orthogonal to the human form – have we not built ourselves out of relevance?
The medium is, indeed, the message.