I study how the introduction of Gutenberg’s printing press shocked the market for ideas and the labor market, increasing the returns to and quantity of science. Professor salaries increased significantly relative to skilled wages after printing diffused. Science professors enjoyed the largest salary increases, the share of university courses on scientific subjects increased, and graduates shifted towards scientific careers. Scientific activity and invention began to grow across cities, particularly where printing interacted with universities and political competition, which previously delivered limited support to science. These changes are not explained by prior economic or cultural trends and predate the Protestant Reformation.