This era of accelerated migration forged a culture increasingly attentive to the idea of the world as a unity, and created a public with a vast and growing appetite for learning about transcontinental travel. It was at just this time that geography emerged, lavishly funded by the state, as a Janus-faced science indispensable for military conquests and intelligence, on the one hand, and given to visions of universal harmony on the other. This was the age of the great universal geographies, bestselling illustrated periodicals such as the French Le tour du monde, and associations like the National Geographic Society. The International Geodesic Association was founded to help map the world accurately, and its scientific missions—like innumerable other expeditions public and private—transformed people’s consciousness of the planet. Scholarly geography boasted world thinkers from Halford Mackinder, founder of the twentieth-century discipline of geopolitics, and the German Frederich Ratzel with his beautifully illustrated three-volume History of Mankind, to the the great anarchist universalists like Elisée Reclus and Piotr Kropotkin, men of the left for whom nationalism was a geographical error and geography was a way of showing humanity’s diverse tribes what they shared.”
Mark Mazower, Governing The World: The History of an Idea, 1815 to the Present (New York: Penguin, 2012), pg. 25.