7. Johannes Gutenberg
Johannes Gutenberg invented one of the most essential devices in the history of the world: the printing press. Prior to his invention, people had to meticulously copy books by hand. As a result, books became prohibitively expensive for all but the wealthiest few. Reading was far from being a luxury for the poor; those not in the ruling class could scarcely even read. The printing press used letter blocks that could be replaced so that printers could mass-produce texts. Books became much cheaper, and soon mass-distributed literature led to the Renaissance and Reformation, which together pulled Europe out of the Middle Ages.