Editing Marshall McLuhan (section)

==== Beyond existing communication models ====
"All Western scientific models of communication are—like the [[Shannon–Weaver model]]—linear, sequential, and logical as a reflection of the late medieval emphasis on the Greek notion of efficient causality."<ref>''The Global Village'', p. 77.</ref> McLuhan and Powers criticize the Shannon-Weaver model of communication as emblematic of left-hemisphere bias and linearity, descended from a print-era perversion of Aristotle's notion of efficient causality.

A third term of ''The Global Village'' that McLuhan and Powers develop at length is [[Tetrad of media effects|The Tetrad]]. McLuhan had begun development on the Tetrad as early as 1974.{{sfn|M. McLuhan|E. McLuhan|1988|p=74}} The tetrad is an analogical, simultaneous, fourfold pattern of transformation. "At full maturity the tetrad reveals the metaphoric structure of the artifact as having two figures and two grounds in dynamic and analogical relationship to each other."<ref>''The Global Village'', p. 78.</ref> Like the camera focused on the Earth by the Apollo 8 astronauts, the tetrad reveals figure (Moon) and ground (Earth) simultaneously. The right-brain hemisphere thinking is the capability of being in many places at the same time. Electricity is acoustic. It is simultaneously everywhere. The Tetrad, with its fourfold Möbius [[topological structure]] of enhancement, reversal, retrieval and obsolescence, is mobilized by McLuhan and Powers to illuminate the media or technological inventions of cash money, the compass, the computer, the database, the satellite, and the global media network.