The Invention of Nature is built around a chronological account of Humboldt's life. Born in 1769, he was one of two brothers from an aristocratic Prussian family, raised by a mother with progressive ideas about education who employed outstanding tutors. He spent the years from 1799 to 1804 exploring in South America and visiting Mexico and the United States. After a long sojourn in Paris, writing up his discoveries and using up his inherited fortune to fund his own publications and help other scientists, he moved to Berlin and took up a position as a chamberlain to the Prussian king. At sixty he led an expedition to Russia and Central Asia and at seventy-five he published his five-volume Cosmos, an attempt to integrate all the sciences — astronomy, geology, meteorology, geography, zoology, botany, physics and more — into a unified view of nature.
Wulf doesn't attempt psychological analysis in this, but her account brings out the intensity with which Humboldt was driven — to explore, to measure and understand, but also to appreciate and to share his passion and his knowledge. And it conveys his generosity and courage, alongside less attractive tendencies to arrogance and self-promotion.
Complementing this core narrative, eight chapters (some 40%) of The Invention of Nature each focus on a key scientist, writer or leader influenced by Humboldt; some of these are effectively short biographies in themselves. Five of them are placed within the narrative: Goethe features right near the beginning, since he was as much an influence on Humboldt as the other way around; Jefferson when Humboldt visits the United States; Bolivar at the start of the Latin American revolutions; Darwin at the point of the Beagle voyage; and Thoreau following the publication of Cosmos. The chapters on George Perkins Marsh, Ernst Haeckel, and John Muir come at the end, where along with an epilogue they give a feel for the breadth of Humboldt's influence.
As its title suggests, The Invention of Nature emphasizes Humboldt's contribution to the modern concept of nature, and to ecology, the environmental movement and conservation; this came from the holistic approach he took in his own work and writings and through those on whom he was a fundamental influence (most notably Thoreau, Marsh and Muir). It also captures something of the huge range of his scientific work — he was perhaps the last of the great polymaths — but also its broader aspects. Humboldt linked a mass of fine detail to the broader picture, built extensive research networks, supported younger scientists, and so forth. In this he resembled Darwin, on whom he was a major influence: Humboldt's Personal Voyages was the direct motivation for the Beagle trip, but Darwin drew on Humboldt's ideas and work throughout his life.
Another recurring theme, highlighted in the connections with Goethe and Haeckel, is the way Humboldt saw no divide between art and science, between the appreciation and the measurement of nature. And, despite his aristocratic background and employment for much of his life by one of Europe's more authoritarian regimes, he was a die-hard liberal: a supporter of the United States, an adamant opponent of slavery, and enthusiastic (if later disillusioned) about the South American revolutions. Some of this is explored in the connections to Jefferson and Bolivar.
There is no need to exaggerate or overplay anything in this and to her credit Wulf doesn't. There is no attempt to argue that Humboldt had any direct role in Darwin's conception of natural selection, for example, or in Bolivar's conversion from layabout to statesman and leader. And while three of Wulf's earlier books were on the history of gardening, she manages to avoid giving that too much emphasis here.
Wulf includes some general background — on Prussian politics and the German Question, for example, or on the then current theories of geology — but only as needed. Similarly, with the biographies she concentrates on the connection with Humboldt but provides some broader biographical context, especially with the less well-known figures. And overall she finds an excellent balance, between biography and history of science, between Humboldt and the other figures, and between narrative and exposition. The Invention of Nature is both informative and entertaining, and deserves to be widely read.