From “The WEIRDest people in the World”:

By the 16th century, a mobile community of individualistic and analytically-oriented thinkers had begun to form a loose web called the Republic of Letters that networked much of western and central Europe. Members of this virtual community sent one another handwritten leters often carried on the wings of commerce or by postal services, which were both public and private. Intellectuals penned letters about their ideas to friends and colleagues as well as to other correspondents around Europe. Upon reaching key nodes, important communications were often translated (if necessary, hand-copied, and sent out to other network members in a kind of starburst pattern. This not only linked thinkers in France, Brit-ain, Holland, Germany, and northern Italy but also networked far-flung intellectuals like the mathematician Marino Ghetaldi in Croatia, who constructed the first parabolic mirror, and Jan Brożek in Krakow, who showed mathematically that the hexagonal honeycombs used by bees represent the most efficient solution to storing honey. Both scientists had spent time at a nodal university (Padua) at the core of the Republic, and Ghetaldi became pen pals with Galileo. Crucially, these axonal connections defied political boundaries: British intellectuals, for example, continued to interact with their Dutch counterparts through three wars, and French thinkers learned about Newton's contributions in his Principia (1687) despite incessant wars between Britain and France throughout this era.