What is a Tetrad?

From UMR to LoM

Back in 1964, Marshall McLuhan published Understanding Media: The Extensions of Man (UM). In around 1972, the publisher came to McLuhan about doing a tenth anniversary edition. Marshall thought this was a great idea, a chance to address some of the criticisms he’d received in the years since UM came out. The main criticism he wanted to address was of the “that’s all fine and well, Marshall, but it’s not scientific” type.

Tetrad - a group of four

‘Tetrad’ means ‘a group of four’ — as ‘triad’ means ‘a group of three’, and ‘dyad’ means ‘a group of two’, et cetera.

ENH (enhance)

First, extension: as an ‘extension of man’ (subtitle to UM) every technology extends or amplifies some organ or faculty of the user.” [LoM viii]

OBS (obsolesce)

Then, the attendant ‘closure’: because there is an equilibrium in sensibility, when one area of experience is heightened or intensified, another is diminished or numbed.” [LoM, viii]

REV (reverse)

…a third, with a chapter of its own in UM (‘Reversal of the Overheated Medium’): every form, pushed to the limit of its potential, reverses its characteristics.” [LoM, viii]

RET (retrieve)

At first we thought retrieval entailed only the recasting of whatever formed the content of the new form. That is does (the content of any medium is an older medium) and considerably more.” [LoM, viii]



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