In the German-speaking states of the 1840s and 50s, revolution was in the air. While the political revolutions of 1848–1849 are best known, the life sciences were undergoing their own revolutions, marked by radical new ideas about the organization and transformations of living beings. This project focuses on a cluster of leading German life scientists of the period to examine their participation in the events of this era, both political and intellectual. How did they understand the relations of their scientific work to key political issues of the time, in particular the politics surrounding religion and materialism? In articulating their views on biological organization and its metaphysical and political implications, how did they navigate the roles of Wissenschaftler and citizen? In this study, the dynamic relations among these roles are investigated through comparison of the scholarly and popular works of both established and institutionally un-anchored animal and plant physiologists, in a period in which what counted as “popular” and “professional” writing about living things was being established anew. It thus seeks to add a political layer to previous studies of the materialism debate of the 1850s and also to studies of the co-evolution of popular and professional science in the nineteenth century.