Nicholas J. Rengger was never a member of the English school of international relations. But throughout his career he carried on a conversation with its members, past and present, and that dialogue shaped his own thought. This chapter explores that dialogue to cast light on Rengger’s wider project in international political theory. It argues that while Rengger repeatedly declared the English school a ‘dangerous place to be’, rejecting both its conception of international society and its ethics, he shared its commitments to historicism and interpretivism in the analysis of international relations. It observes too that Rengger’s anti-Pelagianism, as it evolved after the events of 9/11, bears striking similarities with the anti-progressivism favoured especially by Martin Wight, albeit without the overt grounding in Christian theology.