Tetrad laws of media probes


Laws of Media
Laws of Media
  Chains etc.
Medium is the Message
  Start Here
  First Law of Motion
  Second Law of Motion
  Third Law of Motion


Laws of Media: Chains, Clusters, Rings, Spirals and Wheels

While an individual tetrad is worthy of study, the relationship between tetrads is even more exciting. These relationships have been described as chains, clusters and rings by McLuhan. Paul Levinson also has contributed the concept of Tetrad Wheels or Spirals.

These relationships are the basis for surfing tetrads on this site. This is an enhancement that hypermedia provides that is not available in the sequential nature of books.


"A chain forms when, for example, one tetrad's reversal (or retrevial, etc.) provides the subject of the next tetrad, or provides the enhancement (etc.) of the next tetrad." LM p. 130 It is very common for one artifact to be obsolesced by an artifact that was obsolesced by another artifact. This is the march of history. For example, the Iron (Age) obsolesced the Bronze (Age) which obsolesced the Stone (Age).

Chains provide the most common link between tetrads. Enjoy surfing these links. Some can be considered as timelines. [It would be really cool to create a timeline as you surf through tetrads.]


"Clusters form where a group of tetrads has one or another of the four laws in common, as when several different media each obsolesce visual bias, or retrieve oral forms, or reverse into some mode of culture." LM p. 130 This points to a simaritiy of the artifacts.

Cirles or Rings

While uncommon, you can find two tetrads where the reversal (or retrevial, etc.) of one subject is the reversal of the other. "Laws of Media" provides an example of litotes and hyperbole.

Wheels and Spirals

Levison states "there is a cyclical but progressive relationship among the media among the media and their effects" DM p. 191 But "it is not just a circle - and so it might better be termed a spiral". Levinson says that clusters and chains are "the equivalent of my intersecting wheels or spirals." His brief mention in Digital McLuhan does not provide enough information. Hopefully at a future date I will be able to read his paper on the subject: "Tetradic Wheels of Evolution."

Author: Ray Daly
Updated: Update-Goes-Here