The Humboldt Current: Nineteenth-Century Exploration and the Roots of American Environmentalism (review)

At a time when most scientific thinkers depended on deduction from universally observable forces and theoretical speculation without experience, Alexander von Humboldt looked outward, regarding the earth as his laboratory. Europeans had done so before. Linnaeus addressed the learned men of Uppsala in 1741 on the benefits of traveling in one's own country. He exhorted his audience to walk with fresh eyes through their native landscape, "through its fields and roads; a kind of traveling, I confess, hitherto little used, and which is looked upon as fit only for amusement."¹ Linnaeus invented travel for botanical classification, but Humboldt invented the scientist as explorer.

Sachs presents a narrative of Humboldt's ideas and his adventures but mostly of his influence on a handful of key American disciples—Jeremiah N. Reynolds, John Muir, Clarence King, and George Wallace Melville. The essence of what Sachs calls the "Humboldt current" is a scientifically informed yet deeply romantic critique of industrialism, developed and enforced by travel and careful observation. Sachs calls Humboldt an ecological thinker because he refused to see the earth as a jumble of disconnected places and phenomena but as a single coherent system, comprised of the same elements, the same forces, the same life forms in different contexts and configurations.

A distinctly Germanic vision is at work in Humboldt's career; Sachs avoids it in favor of other subjects. Humboldt exhibited patterns of thought that connect him to Georg Wilhelm Friedrich Hegel, the leading philosophical thinker of his time. The search for a transcending spirit in all things, a commitment to freedom of both mind and body and a belief that behind the complexity of reality lies a deeper simplicity run throughout the writings of the German intellectuals—including the political economist Friedrich List and the chemist Justus von Liebig—who learned to think deeply from Hegel. Environmental historians have spent decades parsing the works of English poets and painters but have given little attention to German environmental thought.

Did Humboldt influence American environmentalism? Did he put down some of its first roots? Sachs makes the case that Humboldt's sense of unity between humans and their environments (infused with racial tolerance, in opposition to the less admirable geographical determinists whom he also influenced), and a belief in the power of grand synthesis represent a lost founding. Professional science, emphasizing controlled experiment and embodied by specific disciplines, nullified Humboldt's roaming poetics. Arguing for Humboldt's direct influence on twentieth-century activists does not yield much of a reward. Sachs does better when he embraces wandering as an archaic act that binds people to land by erasing lines of property and law.

Sachs' book has guts and spirit. It assembles personalities and ideas, and proposes to change how historians understand Humboldt and his influence by orienting his discussion toward the development of environmentalist thought. He succeeds in presenting the lives that Humboldt touched, the length of his shadow, and the ways in which people in the Western world began to imagine earth in the modern era.