ABSTRACT Through an investigation of the public, professional, and private life of the Darwinian disciple George John Romanes, this essay seeks a better understanding of the scientific motivations for defending the practice of vivisection at the height of the controversy in late Victorian Britain. Setting aside a historiography that has tended to focus on the arguments of antivivisectionists, it reconstructs the viewpoint of the scientific community through an examination of Romanes's work to help orchestrate the defense of animal experimentation. By (...) embedding his life in three complicatedly overlapping networks—the world of print, interpersonal communications among an increasingly professionalized body of scientific men, and the intimacies of private life—the essay uses Romanes as a lens with which to focus the physiological apprehension of the antivivisection movement. It is a story of reputation, self‐interest, and affection. (shrink)