A theory of cultural change is impossible without knowledge of the changing sense ratios effected by various externalizations of our senses. (p. 49) - Marshall McLuhan

In tetrad form, the artefact is seen to be not netural or passive, but an active logos or utterance of the human mind or body that transforms the user and his ground.

"There is an impression abroad that literary folk are fast readers. Wine tasters are not heavy drinkers. Literary people read slowly because they sample the complex dimensions and flavors of words and phrases. They strive for totality not lineality. They are well aware that the words on the page have to be decanted with the utmost skill. Those who imagine they read only for "content" are illusioned."

Language is metaphor in the sense that it not only stores but translates experience from one mode into another. Money is metaphor in the sense that it stores skill and labour and also translates one skill into another.