Paul Ramsey was one of the most prominent writers on just war in the 20th century. An eminent moral theologian in the Methodist tradition, Ramsey’s contribution makes use of Saint Augustine’s writings in unexpected ways. Often controversial and sometimes even polemical in style, Ramsey’s writings depart from the traditionally developed just war principles. Choosing not to draw on Augustine’s just war writings, Ramsey instead bases his moral theology around the concept of agape, arguing that the use of force is sometimes the most loving action to protect the innocent. Through his doctoral supervisor, H. Richard Niebuhr, Ramsey came to appreciate the ‘conversionist’ or ‘transformist’ strand of Augustine’s thinking, itself based on agape, and through the influence of H. Richard’s brother, Reinhold, Ramsey espoused an Augustinian political realism which greatly affected his theological perspective. This thesis therefore traces these various influences in Ramsey’s just war writings, highlighting as well that such Augustinian foundations are strongly evident in Ramsey’s commentaries on Pacem in terris and Gaudium et spes.