This essay argues for the relevance of the history of family life to the history of science, taking the example of the Exners of Vienna. The Exners were an influential case of the nineteenth‐century European phenomenon of the “scientific dynasty.” The focus here is on their collaborative research on color theory at the turn of the twentieth century. At first glance, this project looks like a reactionary strike against aesthetic innovation, a symptom of what historians assume was an unbridgeable gulf (...) between scientific reason and artistic modernism. We can better understand the Exners’ motivations by situating this research at the intersection of the family's public and private lives. The domestic context sheds light on their use of such scientific terms as “subjective,” “normal,” and “universal,” providing a more nuanced sense of what rationality really meant in fin‐de‐siècle Vienna. (shrink)