This study is the most comprehensive account to date of modern treatments of the love commandment. The author examines the literature on agape from Nygren's Agape and Eros in 1930. Both Roman Catholic and Protestant writings are considered, including those of D'Arcy, Niebuhr, Ramsey, Tillich and above all, Karl Barth. The frist seven chapters focus on the principal treatment in the theological literature as they relate to major topics in ethical theory. The last chapter explores further the basic normative content of agape and discusses some of the most characteristic problems.