This contribution to the  Common Knowledge  symposium “Peace by Other Means” argues that the drive for self-esteem, achieved by gaining honor or standing, has been a root cause of violent conflict and war throughout history and that peacemaking that does not take account of what the Greeks called  thumos  is bound to fail. Using an original data set of all wars since 1648 (the Peace of Westphalia) involving great or rising powers, the essay shows how wars associated with honor, standing, and revenge, all expressions of  thumos , far outnumber those caused by security or material concerns. At the same time, it is argued, diplomacy and the theory of international relations have turned increasingly toward belief that conflicts are resolved only by negotiation based on the rational consideration of material interests. The author concludes that conflict resolution needs to rethink its presumptions in comparison with those of Greco-Latin literature and philosophy.