McLuhan’s tetrads: what they are and how they work

Late in his life, Marshall McLuhan developed the idea of using tetrads to apply a consistent mode of analysis to different media. The idea behind them is simple: to make sure that you ask the same questions in the same way about different media.

In the Laws of Media(1988), written by McLuhan with his son Eric and published posthumously, he argues that tetrads are “a means of focusing awareness on hidden or unobserved qualities in our culture and technology”. This follows from his argument that all “human artefacts are human utterances, or outerings, and as such they are linguistic and rhetorical entities. At the same time the etymology of all of all human technologies is to be found in the human body itself: they are, as it were, prosthetic devices, mutations, metaphors of the body or its parts”. (p128).

McLuhan argues that the effects of every media can be viewed in four ways, and that the tetrad offers an “exegisis on four levels, showing … the logos-structure of each artefact, and giving its four ‘parts’ as metaphor, or word” (p128). The tetrad is therefore a grid with four sections.

The four laws of media are described at the Libraries and Archives of Canada website. The site points out that

these four laws exist simultaneously. Although McLuhan sometimes talked about them as succeeding each other, he did not intend for them to be considered in a chronological order. The tetrad is not meant to be a scientific tool, but one for exploration of the “grammar and syntax” of each artefact, a dynamic tool to describe “situations that are in process.”(p116)

It explains that they “further exhibit McLuhan’s abiding concern with pedagogy: they are meant to be used as tools to analyze the patterns of effects that different technologies produce. McLuhan phrased them as questions with which to consider any artefact:

What does it enhance?
What does it make obsolete?
What does it retrieve that had been obsolesced earlier?
What does it flip into when pushed to extremes?”

You can find several clear and simple examples of the tetrad in action at Scott Bennett’s page at Horton.

The ideas behind the tetrad are explained in more detail by Anthony Hempell. He describes

• enhancement as “the amplification of effects” with a “focus on the practical”. It involves the “creation of vortices of power” and presents a “solution to previous problem”;
• retrieval as “the recovery of values and insight” previously “lost or eroded”. It can involve the “transition of ground to figure”; that is, the movement of a phenomenon from the periphery to the centre of attention;
• obsolescence as “the erosion of formerly significant artifacts”. This reverses the transition above causing a “transition of figure to ground” in which some previsouly important phenomenon is moved to the periphery;
• reversal as “the reverse of enhancement; the unexpected dissatisfactions. Pushed to its limits, the artifact flips on its user” and creates new problems.

There is also a very useful entry in Wikipedia.

Finally, there is an interesting discussion about using tetrads to analyse the difference between different web services at Mind Before You Mind.

Give us an example

To give an example we might say that Skype, and other video conference calling software:

• enhances communication at a distance for military, business and commercial uses;
• retrieves personal contact and direct verbal communications as th means of making decisions;
• renders obsolete written orders, memos, requests and thank-you letters;
• reverses into bullying (the loudest voice wins); confusion (who has the right to talk?); indecision (the talking never stops); misunderstanding (individual memories replace written minutes).

This provides one formulation but it is not (it cannot be) the only formulation of the cultural effects of Skype. Tetrads, like mind-maps, are intended as creative tools, as triggers for thought and investigation. The above, like all tetrads, is a creative endeavour, not a scientific result.

The purpose of a tetrad is to provide a coherent set of effects that can be used to spur investigation, by causing us to ask: is that really so? Or: is that all there is to it? Or: are those the most important effects?

The purpose of a tetrad, then, is to provide a considered framework for us think above something that might otherwise remain unobserved.