This essay considers a long-standing controversy between two nineteenth century pioneers in electrophysiology: the German scientist Emil du Bois-Reymond (1818-1896), and his Italian rival Carlo Matteucci (1811-1868). Historians have generally described their disagreement in du Bois-Reymond’s terms: the product of a contrast in scientific outlook. While not discounting this interpretation, I want to suggest that the controversy was driven as much by the rivals’ similarity as it was by their difference
