Stephen T. Casper and Steve Fuller’s commentaries on my paper "Completing Circle of the Social Sciences? William Beveridge and Social Biology at the London School of Economics during the 1930s" raises important questions about the historical entanglement of the political left, welfarism, biology, and social science. In this response, I clarify questions about my analysis of events at the London School of Economics in the early twentieth century and identify ways in which they are important in the present. I suggest that there is much to be learned from the school’s failed experiment with social biology, not least when it comes to thinking about the historical contingency of relationships between progressive politics and biology.