Alexander von Humboldt (1769–1859) was an intrepid explorer and the most famous scientist of his age. In North America, his name still graces four counties, thirteen towns, a river, parks, bays, lakes, and mountains. His restless life was packed with adventure and discovery, whether he was climbing the highest volcanoes in the world or racing through anthrax-infected Siberia or translating his research into bestselling publications that changed science and thinking. Among Humboldt’s most revolutionary ideas was a radical vision of nature, that it is a complex and interconnected global force that does not exist for the use of humankind alone.