The Extension of Man

McLuhan, M., & McLuhan, E. (1992). “Tetrads.” In Laws of media: The new science. Toronto: University of Toronto Press.


Extension; artefacts; history; technology; tetrad.


McLuhan introduces his four-pronged approach to media, arguing that each piece of technology or artefact follows four laws. These laws both draw upon and refute past technologies in order to create something new. Humans then use these technologies as extensions of themselves, as they become our second natures.


“…all human artefacts are extensions of man, outerings or utterings of the human body or psyche, private or corporate” (McLuhan 24).

“As our second nature consists entirely in our artefacts and extensions and the grounds and narcoses they impose, their etymologies are all to be found in first nature, the wild body” (24).

“In other words, the crucial study that remains is that of working out in precise detail the relations between second and first natures: which organs or faculties are extended or stressed or numbed and in which pattern or degree by each one of our artefacts” (25).


While I found McLuhan’s tetrad proposition to be both intriguing and believable, my favorite part of this reading was the discussion of artefacts as extensions of humans. In order to understand the tetrads that McLuhan brings up, we have to go back farther to understand the reason why artefacts exist in the first place. It is through understanding the first and second nature of things that we begin to understand the necessity for new technologies and how they have evolved over time. This is something that we have touched on in class, but it is worth exploring deeper.

How do artefacts become “extensions of man”? Why is it necessary for us to have these extensions? Is this lens for understanding of the world around us what makes it possible to refer to almost anything as a “technology”? These are the concepts that McLuhan explores in the readings this week. Today, the idea of the smartphone or car or other technologies can easily be seen as extensions of the body. It is some of the more obscure artefacts that McLuhan discusses that truly prove his thesis. By explaining how places such as brothels and concepts such as semeiotics fit his thesis, he helps readers see technologies as extensions of the body all around us.

In many cases, we subconsciously allow artefacts to become extensions of our bodies. However, I think that there are some scenarios where we do this intentionally. I play Ultimate Frisbee, and across all teams and experience levels, you will hear coaches and captains telling players to hold, spin, and throw discs in their spare time. As a rookie, this is something that I did a lot in order to get comfortable with the disc. Five years later, holding a disc in my hands is one of the most natural and calming parts of my day.

This is an idea that is reiterated across all sports. Even in Infinite Jest, the boys attending the tennis academy are required to carry a tennis ball with them at all times and squeeze it. In both of these cases, McLuhan would say that these items are becoming an extension of the body.


What is an unorthodox extension of your body that has become second nature in the way that McLuhan describes? Is the process of making something second nature always deliberate? Subconscious? Does this distinction matter?

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