Tetrad

=McLuhan's Tetrad= The "Tetrad" proposed by Marshall McLuhan, was introduced as another way to look at technology's effect on the society around it; as an exploration of the dynamics of formal causality. The object itself is meant to transcend time, being affected by both its environment and the characteristics of each branch of the tetrad itself. The whole purpose of this is to create a "comprehensive awareness" of the artifact being presented and discussed through the tetrad model. The idea is that when one particular branch, or faculty, or 'man' is expanded, a whole new shift in balance takes place, and this in turn affects all the other branches. This is what the tetrad is used for - to help gain some balance and explain what exactly is going on.


 * **Retrieval** is to **obsolescence** as **enhancement** is to **reversal** || **Retrieval** is to **enhancement** as **obsolescence** is to **reversal** ||
 * What is brought back, must also render something obsolete; what is enlarged will always do so at the expense of others. || What is retrieved is an outgrowth of the enhancement (an ancient version of the same metaphor). What is obsolesced creates opportunity for reversal. ||

The four forces are divided into two grounds; figure (technology) and ground (What factors give birth to technology). McLuhan's Tetrad refers to four effects/forces of technological change. The four forces are:

> > >
 * Enhancement
 * Reversal (opposite of enhancement: creation of new challenges, problems)
 * Retrieval (recovery of values from the past)
 * Obsolesence (opposite of retrieval: erosion of values)

Image taken from:

Hempell, Anthoney. The Tetrad: Concept. Online at:  Accessed on: October 3rd 2006. Hugh McDonald. Nature and the Tetrad. Online[|  Accessed: December 6, 2006.