From The Playboy Interview: Marshall McLuhan

“PLAYBOY: How can you be so sure that this all occurred solely because of phonetic literacy–or, in fact, if it occurred at all?

MCLUHAN: You don’t have to go back 3000 or 4000 years to see this  process at work; in Africa today, a single generation of alphabetic literacy is enough to wrench the individual from the tribal web. When tribal man becomes phonetically literate, he may have an improved abstract intellectual grasp of the world, but most of the deeply emotional corporate family feeling is excised from his relationship with his social milieu.

This division of sight and sound and meaning causes deep psychological effects, and he suffers a corresponding separation and impoverishment of his  imaginative , emotional and sensory life. He begins reasoning in a sequential linear fashion; he begins categorizing and classifying data.

As knowledge is extended in alphabetic form, it is localized and fragmented into specialties, creating division of function, of social classes, of nations and of knowledge–and in the process, the rich interplay of all the senses that characterized the tribal society is sacrificed.”