Methods in intellectual history help reevaluate concepts of nature and environment that influence our understanding of European society and politics in the twentieth century. Building off of the theme of “Sustainability and Transformation,” these papers show how ideas about environment and the stability of nature have shaped approaches to human interaction – from visions of social order and political identity, to forms of religious thought, scientific research, and cultural practice. “Disarming the Milieu: Evolution, Environment, and History in Interwar France” examines how the concept of the milieu in French biology shaped national understandings of history, politics, and subjectivity. Debates about biology and reproduction form the basis for “Individualizing the Threat to Human Nature: Genetic Reproductive Politics in Late-Twentieth-Century Germany,” which investigates how a neoliberal individualization of responsibility shaped opposition to prenatal and preimplantation genetic diagnosis in Germany in the 1990s. “Moving Heaven and Mud: Second Nature in German and Japanese Modern Dance” examines how the German modern dance and Butoh movements of the 1930s and 1960s promoted ideas about the creative reinvention of human behavior and society through transformations to stage performance and theatrical environments. Finally, “Theologies of the Anthropocene: Anti-Secularism and the Origins of Christian Ecology in the 1960s,” argues that the ecological turn in Protestant and Catholic theology of the 1960s reformulated interwar polemics against the de-Christianization of Europe by recasting divine social order as one of harmonious interdependence of human and non-human life.