The, classical realist writings of E.H. Carr and constructivist publications of Alexander Wendt are extraordinarily influential. While they have provoked a great number of reactions within the discipline of International Relations, the ethical dimensions of their works have rarely been studied at length. This article seeks to remedy this lack of examination by engaging in an in-depth scrutiny of the moral concerns of these two mainstream International Relations scholars. On investigation, it is revealed that Carr demonstrates a strong commitment to (...) the ethical principle of fairness and Wendt a moral concern for the prevention of the use of organized violence. These concerns are shared by Rawlsians and cosmopolitans in International Relations, and these findings may thereby encourage closer engagement between these diverse communities that rarely speak to one another and strengthen disciplinary research on morals. (shrink)