He then traveled via Switzerland to Paris, where he attended lectures on chemistry and the natural sciences at the Sorbonne. He visited the Jardin des Plantes, the famous botanical gardens, and marveled at its “cabinet of natural history,” which displayed specimens collected from around the world. Before embarking from Boston, Emerson had been reading books about natural history with great interest. The evolutionary views of the French naturalist Lamarck had been gaining favor over the past decade, and Charles Dar win was two years into his voyage aboard the HMS Beagle, collecting the data that would inform the theory of evolution outlined in The Origin of Species. Natural history was the field in which the most innovative science was being done, and Emerson responded powerfully to the new image of the natural world that was emerging, in which all life forms were seen to be intricately interrelated. Viewing the meticulous classification of plant and animal specimens at the Jardin des Plantes confirmed visually what he had been reading and led him in a moment of enthusiasm to declare in his journals, “I will be a naturalist” (Journals and Miscellaneous Notebooks, vol. 4, pp. 198-200). What Emerson was discovering, though, was scientific confirmation for the beliefs that had led him to abandon the forms of organized religion. The systematic exhibition of species displayed in the Paris museums struck him as an elaborate argument from design; even the minute, detailed patterns of a seashell or a fern leaf were indications of the order that permeates creation and gives mute testimony of a Creator.

Emerson left Paris for England on July 18, 1833, pondering how he could direct his own intellectual abilities into productive work on the scale of that of the great naturalists of the nineteenth century. Just as natural science had begun systematically to classify the various life forms of the natural world, Emerson began thinking about how to classify the various intellectual patterns in the spiritual world of human consciousness. He arranged to visit Samuel Taylor Coleridge, the romantic poet and critic, whose writings on philosophy, religion, and the human imagination had played a significant role in Emerson’s education. He also visited William Wordsworth, whom he considered the greatest living poet. However, the person who influenced his intellectual ambitions most during his travels in Britain was Thomas Carlyle, the social critic and historian he had encountered years earlier. Coleridge and Wordsworth were in their sixties and nearing the end of their careers. Carlyle, at thirty-seven, was much more nearly Emerson’s contemporary. Carlyle was opinionated, an advocate of progressive ideas, and a writer determined to address contemporary social and political issues even when writing as a historian or literary critic. It was Carlyle who served as the model for Emerson’s ambitions as a writer and intellectual on his return to America, even if many of Emerson’s more idealistic beliefs antagonized the practical Scotsman.

Emerson’s travels in Europe and England planted the seeds of the idealist philosophy he would outline in his first book, Nature. It would take him three years to finish that work, but he began to work out its argument on the voyage home to Boston. Within a few weeks of his return he delivered a lecture on “The Uses of Natural History,” which can be considered a prospectus for Nature. This lecture was partly an account of what he had learned in Paris and in his own reading on the subject, and partly an effort to tease out a series of moral lessons from these new scientific discoveries about the natural world. The proper “use” of natural history, Emerson believed, was not to be found in what it could teach us about the material world, but in what it demonstrated about the mind’s powers of observation. Our capacity to perceive and comprehend order in nature indicates a deeper truth about the autonomy of human consciousness. The mental processes used to discover the heretofore hidden interrelation of flora and fauna provide a disciplined education in how each individual can discover his or her own relation to the world. “Our dealing with sensible objects,” he would write in Nature, “is a constant exercise in the necessary lessons of difference, of likeness, of order, of being and seeming, of progressive arrangement.... and all to form the Hand of the mind;—to instruct us that ‘good thoughts are no better than good dreams, unless they be executed!’” (p. 27).

At the lecture podium, Emerson was beginning to discover how to translate his spiritual convictions into the language of natural science, which was rapidly becoming the dominant language among the academic and professional classes. Nature was his first and most concerted effort to present a systematic account of how studying the natural world will lead individuals to discover fundamental moral, or spiritual, truths—truths that, in turn, are the ethical basis for action in the world. His argument can start to sound fairly Puritanical when he claims in the “Discipline” chapter that “every natural process is a version of a moral sentence” (p. 30), and insists on our duty to read out the ethical lesson of every event that befalls us in life. However, in the final three chapters, “Idealism,” “Spirit,” and “Prospects,” his argument turns in a radically forward-looking direction. Because the phenomena of the natural world are ultimately symbolic of higher spiritual ideals, the natural world—as well as the human societies built up from its resources—are subject to the ideas of men and, therefore, can be reformed and improved by better ideas. “‘Nature is not fixed but fluid.