My main theme is the extension of the nervous 
system in the electric age and thus the complete 
break with 5,000 years of mechanical technology. 
This I state over and over again. I do not say 
whether it is a good or bad thing. To do so would 
be meaningless and arrogant.

Marshall McLuhan to Robert Fulford, June 1, 
1964, Letters of Marshall McLuhan  , (Toronto, 
1987) p. 300.