ditto device

Printing, a ditto device confirmed and extended the new visual stress. It provided the first uniformly repeatable „commodity,“ the first assembly line—mass production.
It created the portable book, which men could read in privacy and in isolation from others. Man could now inspire—and conspire.
Like easel painting, the printed book added much to the new cult of individualism. The private, fixed point of view became possible and literacy conferred the power of detachment, non-involvement.

Marshall McLuhan, Quentin Fiore: The Medium is the Massage. An Inventory of Effects (1967), p. 50.