The history of science and history of nationalism converge in my dissertation. Nineteenth-century Europe saw a succession of impactful biological ideas, while recasting the most fundamental questions—what humans are, what the origin and fate of humans are, and how humans should live—in a new light. Romanticism is one chapter in the history of science that illustrates how the nineteenth century attempted to answer these questions in its own way, using scientific knowledges available to them. The intensely inward and self-reflective nature of Romantic literature has contributed to the portrayal of Romantics as mystical, philosophical, and emotional. Likewise, the scientific knowledge grounded in Romantic principles has been persistently dismissed as an inferior maverick in the history of science. My work challenges this portrayal and redefines Romanticism as a productive moment, whose understanding of diverse organic forms and their relations to one another not only supported the theories of evolution, but also inspired efforts to empirically process the traumas and divergences in both human and natural worlds. At the same time, my work brings nationalism into dialogue with scientific developments in Europe. Focusing on how French intellectuals perceived their own science as well as “German science” (often equated to “Romantic science,”) I trace a century-long process of reformulating a national Self and its relationship to the Others—a common feature of German Romantic thoughts—in France, where rivalry and skepticism towards Germany prevailed. I also challenge the image of neutrality and independence that is often assumed about scientific knowledge, as well as challenging the Darwin-centered narratives of the history of biological thoughts by giving voice to earlier scholars who proposed other variants of transformism and evolutionism. I use case studies to examine diverse modes of scientific arguments and writings as observed by nineteenth-century scientists, who frequently nationalized these differences and used them as markers for evaluating each other’s ideas. At the center is J. W. von Goethe, the German poet whose scientific ideas were impactful enough to resurface in French scientific discussions even after his death, yet eccentric enough to raise suspicions that often revealed nationalistic undertones. Each case study compares Goethe to a scientist-writer who participated in the French scientific community, such as A. P. de Candolle, Charles Darwin, and Jules Michelet. In addition to researching scientific texts, journal reviews, and personal diaries and correspondences, I focus on the structure and form of scientific texts for textual analyses. I apply digital humanities and visualization method to compare the texts that purportedly represented different national characteristics. These case studies illustrate that Goethe’s reception in France across the century mirrored the transformation in the modes of nationalism in France. The view of Goethe shifted from a national antithesis of French scientific thinking, to a mediator who could bridge the French philosophical tradition to emerging evolutionary science, and then to a model for both national and natural histories. In the process, I reinterpret Romanticism as a broader form of thinking and believing that a collective may adopt in different times and places.