“Alexander von Humboldt and Henry David Thoreau: The Romantic Influence on the American View of Nature”



The American understanding of nature, particularly in the wilderness preservation tradition, is an original and pervasive part of our culture. Henry David Thoreau is a seminal figure in this strand of American thought, but his bequest is in turn indebted in significant ways to the Prussian romantic naturalist, Alexander Von Humboldt.  Specifically, Humboldt provides Thoreau with the model of a lifestyle of immersed and rigorous inquiry into nature and the view of nature as fundamentally relational.  Without this lifestyle of intimate inquiry into nature, Thoreau’s contributions as a naturalist and a philosopher would be unthinkable.



            The American idea of wilderness is rich with mythopoetic and evaluative significance.  Especially in the formative years, wilderness was the core value of the growing preservation and environmental tradition in American culture.  It remains, as embodied in the Wilderness Act, an idea of weight in law and policy matters.  The genesis of this idea is in the American appropriation of trends in romantic philosophy and science.  The story is one of cross-fertilization, with influences going both directions across the Atlantic.  The American naturalist William Bartram, for instance, was a significant influence on the poets Samuel Coleridge and William Wordsworth.  But the figures I shall focus on here are the Prussian scientist Alexander von Humboldt and the American naturalist and philosopher Henry David Thoreau.  Thoreau spoke more of wildness than wilderness, but without Thoreau’s radical vision of nature and humanity’s humble place within it, the affection and reverence for wilderness preached by John Muir and Aldo Leopold would be unthinkable.

            The dominant Western view of nature forged in the enlightenment and scientific revolution is a reductive and mechanistic one.  From Galileo to Newton, all that cannot be quantified in nature was relegated to the world of appearance, and the teleological explanation was disqualified from science.  Francis Bacon set the goal of modern science as the effective domination of nature, and John Locke and Adam Smith declared that land and nature not appropriated and quantified by industry and economics was waste.  The implication of this view is not a reverence for wilderness but rather its denigration as an affront to progress and a call for its conquest.

            The late enlightenment philosopher Immanuel Kant tore a rift in this building and dominant scientific perspective, in large part by undercutting the privileged status of primary qualities.  The quantifiable aspects of experience, that is its spatio-temporal arrangements, are a mock up, a product of the active and constructive nature of cognitive experience.  The primary qualities do not constitute a direct grasp of objective reality but are as much in the domain of subjective experience as the more affective, secondary qualities.  Kant then worked to legitimate the significance of aesthetic judgments, allowing an interpretation of nature as poetic as well as scientific.  “Accordingly, [Kant’s] third critique opens the door to Romanticism generally, and Coleridge, Wordsworth, and Shelley in particular.”[1]

            The Romantic poets threw themselves into a new aesthetic relation to wild nature, writing both of nature’s beauty and of the profundity of their experiences of it.  They were intoxicated by the very aspects of nature which Locke and company had written off as insignificant in both being and consequence—the subjective and affective qualities of its experience.  Nature did not sit idly on the material side of the Cartesian mind/body dualism but claimed affinity and kinship to the spirit and mind of the poet.  Nature pulsed with moral and spiritual energy.  Depending on the poet, it was either the surest path to God or the Divine principle itself.

Ralph Waldo Emerson gave an original, distinctively American, interpretation of Romanticism in his book Nature (1836).  Evaluations of Emerson with regard to the history of environmental thought are mixed.  He exhilarates in the beauty of nature, like Wordsworth finding an affinity to consciousness in it: “… all natural objects make a kindred impression, when the mind is open to their influence;” and “The greatest delight which the fields and woods minister, is the suggestion of an occult relation between man and the vegetable.”[2]  The lover of nature, the uncommon one who still has childlike eyes to see, belongs to nature, and she ministers to him: “Nature says,—he is my creature, and maugre all his impertinent griefs, he shall be glad with me.”[3]  But it is clear that, to Emerson, nature is secondary and subservient in value to human spirituality.  Do not indulge too much in these nature revelings, but turn back to the care of your soul, he says: “beauty in nature is not ultimate.  It is the herald of inward and eternal beauty, and is not alone a solid and satisfactory good.”[4]  Nature still exists for humanity, who will eventually realize its dominion over nature, at which time “disagreeable appearances,” such as spiders and snakes, will be seen no more.[5]

            Henry David Thoreau, early a disciple and companion of Emerson, bears a significant Emersonian deposit in his thinking.

His mentor’s key contribution was helping Thoreau to establish a belief that nature can be known through the immediate activity of inquiring consciousness (or, alternatively, an absolute separation between consciousness and nature does not exist).  This transcendental axiom, or first principle, was the heart of the Emersonian philosophical legacy.[6]

It is Thoreau, however, who is unquestionably the first major luminary in the American wilderness tradition.  "It is no exaggeration," Oelschlaeger writes, "to say that today all thought of the wilderness flows in Walden's wake."[7]  His essay “Walking,” perpetually revised till the end of his life, is equally important in this regard. 

            Thoreau had several significant influences besides Emerson.  He read everything he could get his hands on regarding Eastern thought and spirituality, setting an enduring precedent for American environmentalists.[8]  One especially important influence regarding the idea of nature is the Prussian explorer and scientist Alexander von Humboldt.  Thoreau may even have modeled some portions of his life after him.[9]

So who is this naturalist who exerts such a profound affect on Thoreau and American environmental thought?  Humboldt, a romantic scientist, combined an aesthetic immersion in nature with rigorous scientific inquiry.  His compelling vision of nature was as a complex web of relations, a world fraught with unsuspected interconnections forming a beautiful and intricate harmony.  Though the term would not be coined for many more years, Humboldt’s science was undeniably ecological.  He traveled the world, most notably in the South American tropics, everywhere taking measurements and more measurements—of temperatures, air pressures, magnetic fields, depths, heights and even the blueness of the sky, anything that could be measured.  He provided detailed instructions on what other travelers and expeditions should measure and made himself a clearing house for such data.[10] 

            His own, early description of his project is helpful, especially for its explicitly relational understanding of the unity of nature, that is, as harmony:

I shall collect plants and fossils, and with the best of instruments make astronomic observations.  Yet this is not the main purpose of my journey.  I shall endeavor to find out how nature’s forces act upon one another, and in what manner the geographic environment exerts its influence on animals and plants.  In short, I must find out about the harmony of nature.[11]

            Humboldt’s ecological vision led to a richer understanding of the consequences of human actions.  This in turn provides the ground for a conservation ethic.  A sample exhortation shows him to be remarkably close to contemporary environmental concerns:

“By felling the trees which cover the tops and sides of mountains,” he asserted, “men in every climate prepare at once two calamities for future generations; want of fuel and scarcity of water.”[12]

The want of fuel is easy to predict, but foretelling the scarcity of water demonstrates sophisticated understanding of ecosystem functioning. His ecology also has, as commentator Aaron Sachs says, a “social edge.”[13]  There is no call to simple preservation, but devastating critiques of the violence which European conquest and colonialism had done to the social and ecological relations which constituted the American lands, critiques which grew out of an intimate knowledge of and appreciation for those relations.

            Humboldt’s influence on American culture, although astoundingly unknown today, is hard to overestimate. 

Editions of his books sold out repeatedly.  Ralph Waldo Emerson called Humboldt “one of those wonders of the world … who appear from time to time, as if to show us the possibilities of the human mind”; Henry David Thoreau classified New England’s climate zones according to Humboldt’s model of plant ecology. … Walt Whitman would start to suffuse his poetry with the concept of “Cosmos,” a term that suggested the world’s overarching but mysterious harmony and that Whitman stole directly from Humboldt … It is quite possible that no other European had so great an impact on the intellectual culture of nineteenth-century America.[14]

His influence is especially pronounced among the scientific community and the early conservationists.  Benjamin Silliman, James Dwight Dana, Asa Gray and Louis Agassiz, fathers of American science, all corresponded with Humboldt significantly, and Agassiz relied extensively on his financial assistance.[15]  The contributions of explorer-scientists like J. N. Reynolds and Clarence King would be nearly unthinkable without the influence of Humboldt. 

            Humboldt was also a significant influence on John Muir, who began his career with a naturalist’s expedition initially intended to make directly for the same South American tropics Humboldt described in his Personal Narrative.  California was originally a side-track, and later in life, Muir did finally make it to South America.  “How intensely,” he wrote in an early letter, “I desire to be a Humboldt!”[16]

            Nature for Humboldt is full of affective significance, but it is no mere mirror for the soul.  Rather, Humboldt spoke of “the power of the external world over the emotions of the mind.”[17]  Sachs contrasts this with Emerson’s view that “Nature always wears the colors of the spirit”:

The person who travels openheartedly into the natural world, the explorer who truly attempts to see, can actually be transformed by the experience; he is not doomed simply to impose his expectations onto the landscape. … Emerson never quite understood this possibility, but Thoreau did.  And so did the landscape painter Frederic Church.  And so, too, did America’s entire first generation of landscape photographers and explorer-scientists.[18]

            Science, at its best, is this activity of ‘truly attempting to see.’  Unlike the physico-theologians, Humboldt was not trying to see through nature to God; he wanted to see nature, the cosmos, the harmony of all the parts in “the mysterious relations” of “mutual dependence and connection.”[19]  By focusing on the hidden relations, the underlying patterns and laws, Humboldt took the naturalist’s science far beyond taxonomic classification and well into ecology, without losing any of the comprehensiveness.  It was Humboldt’s idea, for instance, to draw isothermal lines across the map, dividing the world into climatic zones, and to see that these latitudinal divisions were mirrored, in species composition, by zones of elevation on tropical mountains.[20]  Climbing a mountain, one passes through the same zones of vegetation that one passes through on a larger scale when traveling toward higher latitudes. 

            Humboldt’s ecological bequest is largely mediated today by Charles Darwin.  His influence on Darwin was profound: “My whole course of life,” Darwin wrote, “is due to having read and re-read [Humboldt’s Personal Narrative] as a youth.”[21]  Much of Darwin’s famous theory is evidently dependent on Humboldt’s work.[22]  But Darwin put front and center an aspect of nature which was notably muted in Humboldt, “the centrality of conflict and violence in nature.”[23]  The relations of nature are not primarily harmonious but competitive, a war of all against all.  And whereas Humboldt’s ecology motivated a cosmological, egalitarian sociology, “the desert heat of social Darwinism … endorsed both human and environmental exploitation.”[24]

            Thoreau clearly participates in the romantic rejection of the reductive and mechanistic view of nature, affirming its teleological and affective aspects.  But unlike Emerson, and like Humboldt, he does not see these aspects as being in any way for humanity.  The first and longest chapter of Walden is titled “Economy” and is a devastating critique of Adam Smith.  The companionship of wild nature is far more enriching than material wealth, offers Thoreau.  We are better off in fact, the less we are encumbered by the latter.  A relatively small amount of cultivation can supply all the material comfort we really need.  Neither has Thoreau any patience for the Cartesian version of knowledge as certain and objective: “The highest we can attain is not Knowledge, but Sympathy with Intelligence.”[25]

            A fundamental theme in Thoreau’s writing is that nature exists for its own purposes, and is wonderful therein.  This is no mere assumption, but the deliverance of his sympathetic inquiry into nature.  A representative passage from “Chesuncook” in The Maine Woods is described by Oelschlaeger as the clearest and earliest “statement of the preservationist's credo:”[26]

the pine is no more lumber than man is, and to be made into boards and houses is no more its true and highest use than the truest use of man is to be cut down and made into manure. . . . Every creature is better alive than dead, men and moose and pine-trees, and he who understands it aright will rather preserve its life than destroy it.[27]

Thoreau’s reflections on his bean patch in Walden follow a similar tack, finding that nature exists as much for the other animals as for humanity: “These beans have results which are not harvested by me.  Do they not grow for woodchucks partly? … Shall I not rejoice also at the abundance of weeds whose seeds are the granary of the birds?”[28]  Indeed Thoreau is perpetually eager to point out what a small and modest portion of nature belongs to humanity: 

The farmers and their works are scarcely more obvious than woodchucks and their burrows.  Man and his affairs, church and state and school, trade and commerce, and manufactures and agriculture, even politics, the most alarming of them all,—I am pleased to see how little space they occupy in the landscape.[29]

            Wilderness, for Thoreau, stands in an entirely different relation to culture than Locke described.  Wilderness is not waste, waiting to be brought into the sphere of culture as property, lumber for instance, but is the mother and nurse of culture.  Thoreau finds great significance in the story of Romulus and Remus being suckled by a wolf.  This is the context of the frequently cited line, “in Wildness is the preservation of the World.”[30]  If culture does not regularly return to nature, to drink her inspiration afresh, it stagnates and degrades. Wildness is the principle of life and the root of goodness.  As with culture, so with the individual; Thoreau offered an ethic of balancing civilizing influence with an inner wildness: “I would not have every man nor every part of man cultivated, any more than I would have every acre of earth cultivated: part will be tillage, but the greater part will be meadow and forest …”[31]

            Thoreau embraced the romantic dictum to inquire openly of nature, and it led him on a walk into the wilderness—and he spent a large part of his life so walking.

Thoreau’s idea of wilderness is rooted in a lifetime of primary experiences or firsthand meetings with nature.  Not only did he live in the wilderness alongside Walden Pond for more than two years, but he ranged widely and frequently over New England and journeyed on occasion to Canada and Minnesota.  Thoreau climbed mountains, explored the vast, densely forested regions of Maine, and floated rivers.  And he walked—day-hiked, in the popular idiom—almost every day of his life.[32]

He came back with a new view of nature.  (An American original relation to the universe?)  Nature is not the knowable, quantifiable atoms-in-the-void of science.  Indeed, “Nature is a personality so vast and universal that we have never seen one of her features.”[33] Nor is nature a contemplative ladder, whose end is to lead us to the eternal beauty beyond her.  No, says Thoreau, only with metaphor can I show you: “Here is this vast, savage, howling mother of ours, Nature, lying all around, with such beauty, and such affection for her children, as the leopard.”[34]

            Thoreau’s vision of nature is not any more the vision of a purely contemplative poet than the vision of a Newtonian scientist.  It is the relational and ecological view of a field naturalist.  And it is for this perspective that Thoreau is indebted to Humboldt and his ecological focus on relations and interconnections.  When two translations of Humboldt’s Ansichten der Natur were made available, Thoreau bought both.[35]  He classified vegetative regions in New England according to Humboldt’s schemes. The obsession in Walden with measuring the depths of the ponds and recording freezing and thawing dates seems due also to his influence.  But, while Thoreau always exhibited a careful attention to and moral regard for nature, it is the Thoreau after Walden that is most interesting in this regard.  After his Walden experience, Thoreau turned his attention more and more to science.  He read Linnaeus, Lyell and even the early Darwin.[36]  He turned his attention to ecological questions.  He became a pioneering expert on the workings of forest succession, was indeed one of the first to use the term.[37]  For instance, it was Thoreau that solved several ecological riddles by demonstrating the important role played by squirrels in distributing the seeds of trees.[38]   Worster tells us that “even Louis Agassiz … was not his superior as a field naturalist.”[39]  His studies of the area lakes were a rigorous and lasting bequest to limnology as well.[40]

            He became especially interested in understanding what New England must have been like before the arrival of whites, and whether the forest could be restored, a question startlingly anticipatory of modern environmental work.

I take infinite pains to know the phenomena of the spring, for instance, thinking that I have here the entire poem, and then, to my chagrin, I hear that it is but an imperfect copy that I possess and have read, that my ancestors have torn out many of the first leaves and grandest passages, and mutilated it in many places.  I should not like to think that some demigod had come before me and picked out some of the best of the stars.  I wish to know an entire heaven and an entire earth.[41]

There is even a passage in which Thoreau anticipates the idea of a climax to succession, of a community of species best fitted to the geographical conditions:

In a wood that has been left alone for the longest period the greatest regularity and harmony in the disposition of the trees will be observed, while in our ordinary woods man has often interfered and favored the growth of other kinds than are best fitted to grow there naturally.[42]

            All of Thoreau’s discussions of nature, whether aesthetic or scientific, are all rooted in his commitment to a daily, immersive intimacy with nature.  And his intimate familiarity with the diversity of life around him was startling.

Thoreau’s knowledge of the lands surrounding Concord was so vast that some of the town’s children believed that, like God, Henry had created it all.  His knowledge of flora was so precise, a rare fern species not seen for a hundred years was recently rediscovered by examining his surveying notes, and his examination of the succession of forest trees is a seminal essay for modern ecology.[43]

The later Thoreau did not leave any major published works spelling out the more ecological view of nature he was developing, but his extensive journals from this period are a rich bequest still appreciated by naturalists, both amateur and professional.[44] 

            Sachs, though perhaps a little too eager to see everything in terms of Humboldt, gives a good sense of the enormous promise that was cut off by Thoreau’s early death:

Just as the French poet Charles Baudelaire … found a soul mate reflected in the horrific work of Edgar Allan Poe (himself an admiring reader of [Humboldt’s] Cosmos), so did Thoreau dedicate himself to interpreting Humboldt. … Many scholars of American literature have expressed dismay at his seeming descent into scientific list making in the 1850s, but [Laura Dassow] Walls argues persuasively that Thoreau died in 1862 while still trying to work out in his journals and essays what Humboldt’s social ecology meant for the United States.[45]

            Thoreau’s rich and seminal view of nature and the place of culture within it grew out of a lifestyle of immersive, rigorous inquiry into nature, understood relationally and teleologically.  This lifestyle, the methods of inquiry and the relational lens are substantially the bequest of Alexander von Humboldt.



[1] Oelschlaeger, The Idea of Wilderness, 115.

[2] Emerson, “Selections from Nature (1836),” 28, 30.

[3] Emerson, “Selections from Nature (1836),”  29.

[4] Emerson, Nature, quoted in Coates, Nature, 136.

[5] Quoted in Oelschlaeger, The Idea of Wilderness, 135.

[6] Oelschlaeger, The Idea of Wilderness, 134.

[7] The Idea of Wilderness, 171.

[8] Coates, Nature, 96.

[9] Sachs, Humboldt Current, 97.

[10] Sachs, Humboldt Current, 26.

[11] Cited in Worster, Nature’s Economy, 133.  Other translations read “unity of nature.”

[12] Sachs, Humboldt Current, 77-78.

[13] Humboldt Current, 13.

[14] Sachs, Humboldt Current, 4.

[15] Sachs, Humboldt Current, 93.

[16] Sachs, Humboldt Current, 27.

[17] Sachs, Humboldt Current, 95.

[18] Humboldt Current, 95

[19] Quoted in Sachs, Humboldt Current, 76.

[20] Worster, Nature’s Economy, 134.

[21] Worster, Nature’s Economy, 132.

[22] Sachs, Humboldt Current, 241.

[23] Worster, Nature’s Economy, 137.

[24] Sachs, Humboldt Current, 13.  Leopold, among others, will find a very different social upshot to Darwin, one much more egalitarian.  But social Darwinism, which held that the hardships and carnage of economic and military competition were necessary correlates of social progress and should not be avoided, certainly had center stage for awhile.

[25] Thoreau, quoted in Oelschlaeger, The Idea of Wilderness, 166-67.

[26] The Idea of Wilderness, 150.

[27] Walden and Other Writings, 398.

[28] Thoreau, Walden and Other Writings, 228.

[29] Thoreau, “Walking,” 32.

[30] “Walking,” 37.

[31] “Walking,” 40.

[32] Oelschlaeger, The Idea of Wilderness, 136-37.

[33] “Walking,” 41.

[34] “Walking,” 40.

[35] Sachs, Humboldt Current, 96.

[36] Worster, Nature’s Economy, 63.

[37] Waller, “Getting Back to the Right Nature,” 560;

[38] Worster, Nature’s Economy, 70.  See his lecture, published several times, “The Succession of Forest Trees.”

[39] Worster, Nature’s Economy, 88.

[40] Worster, Nature’s Economy, 88.

[41] Quoted in Worster, Nature’s Economy, 66.

[42] Quoted in Worster, Nature’s Economy, 72.

[43] Turner, The Abstract Wild, 86-87.

[44] Worster, Nature’s Economy, 61.

[45] Sachs, Humboldt Current, 97.