Man of the world

The Invention of Nature: Alexander von Humboldt’s New World. By Andrea Wulf.Knopf; 496 pages; $30. John Murray; £25.

IN A superb biography, Andrea Wulf makes an inspired case for Alexander von Humboldt to be considered the greatest scientist of the 19th century. Certainly he was the last great polymath in a scientific world which, by the time he died in Berlin in 1859, aged 89, was fast hardening into the narrow specialisations that typify science to this day. Yet in the English-speaking world, Humboldt is strangely little-known. That is partly because polymaths are out of fashion. But it is also because Humboldt suffers, given the legacy of two world wars, from having been German. In 1869 thousands marched in Ohio to celebrate his centenary. Fifty years later German books were burnt in a huge public bonfire in Cleveland, while in Cincinnati Humboldt Street was renamed after that mediocre president, William Howard Taft.

Once, Humboldt seemed to be on everybody’s lips; his portrait even hung in the palace of the King of Siam. Born into an aristocratic Prussian family, he showed an early and insatiable curiosity for the natural worlds “perpetual drive”, he said, as if chased by “10,000 pigs”. As young men he and his brother, Wilhelm, were lights in Berlin’s intellectual circle which, though admittedly small, included Johann Wolfgang von Goethe and Friedrich Schiller. But always Humboldt was consumed by Fernweh, a longing for distant places. His misery was to be “too good a son”. A cold and distant mother (his father had died when he was young) had strict ideas about what it meant to be a member of the Prussian elite. In 1790, at 21, he was all set for a career in the ministry of mines. Then came Humboldt’s jubilee with the death of his mother and a generous inheritance.

Suddenly vistas opened; the dutiful son did not even attend his mother’s funeral. Resigning his position as a mining inspector, he rushed about Europe buying meteorological instruments and the necessaries for conducting electrical experiments. He sought knowledge of astronomy, botany, geology and zoology. Above all he sought a destination: Greece, Lapland, Siberia, the West Indies, even the Philippines—in his excitement, it seemed not to matter where.

In the end the French revolutionary wars then consuming Europe and spilling out into the North Atlantic narrowed the options. With Aimé Bonpland, a talented young French botanist whom he had met in the corridors of their rooming-house in Paris, Humboldt headed on a Spanish frigate for South America. He was, among other things, fleeing the ghost of his mother, which was by now preying on his filial guilt. In July 1799 they landed in Cumaná on the coast of New Andalusia, in modern-day Venezuela.

Humboldt’s five years of travels with Bonpland in South America made his reputation. The red-blossomed palm trees, the pink flamingos, the blue-and-yellow crayfish—there was so much to catch their attention that they ran around “like fools”, he wrote. They pushed on up a tributary of the Orinoco until they found a route to the Amazon, confirming that the two great rivers shared a watershed. And they inspected volcanoes: on Chimborazo they climbed higher than anyone had done before: 19,413 feet (5,917 metres), according to the barometer they carried.

They returned to Europe to a hero’s welcome, their cases groaning with specimens; 2,000 new species of plants alone, which was astonishing given that only 6,000 had hitherto been recorded. The account of their travels, “Voyage to the Equinoctial Regions of the New Continent”, eventually ran to 34 volumes. One, Humboldt’s “Personal Narrative”, became a bible to young scientists, dreamers and adventurers. His was an unabashedly emotional response to nature. Intuition was paramount.

At a time when scientists saw their duty as chiefly taxonomic—stuffing things into ever narrower categories—Humboldt’s genius was to see the interrelatedness of things—in particular the link between plants, climate and geography. Nature was a web of life. He introduced the idea of vegetation zones slung around the globe; he also invented isotherms, lines of equal temperature. He was the first person to be alive to man’s ecological impact—for instance, the effect of deforestation on patterns of rainfall and soil erosion. In Latin America these effects were amplified by the slavery Humboldt witnessed and to which he remained implacably opposed.

Humboldt’s human connections were as fecund as those he made in the natural world. He was friends with Goethe, Thomas Jefferson and Simon Bolívar. His conversations glittering stream of knowledge—was legendary in Europe’s salons. Budding scientists worshipped him for the encouragement he gave them.

Eventually, and only with extreme age, did his endless monologues come to grate on listeners. By then Humboldt, a lifelong republican who depended on Prussia’s absolute monarchs for a stipend, was weighed down by his chores at court and by having to answer so many letters—as many as 4,000 a year from admirers that he was obliged to take out a newspaper advertisement begging “the people of the two continents not to be so busy about me”. Soon after, he was dead.

Yet, and here Ms Wulf is especially good, his ideas enjoyed an afterlife. On the day of Humboldt’s death, Charles Darwin wrote to his publishers to say that the first chapters of his “On the Origin of Species” were nearly ready; the passion and precision of that revolutionary work owe a huge, acknowledged, debt to Humboldt. Henry David Thoreau and John Muir, America’s two most influential naturalists, shared both Humboldt’s wonder for the world and his conviction that knowledge could, in his words, never “kill the creative force of imagination”. Ecologists today, Ms Wulf argues, are Humboldtians at heart. With the immense challenge of grasping the global consequences of climate change, Humboldt’s interdisciplinary approach is more relevant than ever.