Book excerpt: Reinhold Niebuhr was a theologian, writer, and public intellectual who influenced religious leaders and social activists in the United States over four crucial decades in the middle of the twentieth century. The Oxford Handbook of Reinhold Niebuhr traces the development of his work through those years and provides an introduction to the dialogue partners and intellectual adversaries whom he influenced and who shaped his own thinking. It deals with major topics in theology and ethics, providing systematic focus to Niebuhr's wide-ranging works that were directed to many different audiences. Later chapters examine Niebuhr's contributions to political thinking and policy making on issues including international relations, pacifism and the use of force, racial and economic justice, family life and gender equality, and environmental concerns. The concluding section examines Niebuhr's legacy and continuing influence.