The Printing Press - This may seem unimportant, but it truly is. Gutenberg's press, with its movable type, started the idea of publishing oral knowledge or multiplying exissting, hand-written books. This may actually be the reason why so many people turned their backs on Christianity, putting a Bible in the hands of anybody who wanted one. The Church no longer possessed the absolute truth, and thus the independently thinking individual emerged as the key unit of society. In the longer term, publishing universalized literacy.