Around 1450 in Mainz, Johannes Gutenberg combined movable metal type, oil-based ink, and a converted wine-press into a machine that could reproduce a page hundreds of times. For the first time a text could be copied without a scribe — quickly, cheaply, and identically.
Within fifty years presses were running in more than two hundred European cities, and millions of books had been made. Knowledge once locked in monasteries and the memories of the few could now be held, compared, and argued over by the many.
Every upheaval that followed — the Reformation, the Scientific Revolution, the spread of literacy itself — moved on paper the press had made. It invented no new ideas, but it made them impossible to contain.