“Moral Man and Immoral Society: A Study in Ethics and Politics” by Reinhold Niebuhr, published in 1932, examines the contrast between individual morality and collective behavior in society. Niebuhr argues that while individuals are capable of ethical behavior, groups, including nations and societies, often act in selfish, power-driven, and immoral ways. He believes that people in groups are less likely to be guided by moral principles due to the collective pursuit of interests like power, security, and economic gain.

Niebuhr critiques the optimism of liberal thinkers who believed that rationality and cooperation could lead to social justice and peace. Instead, he asserts that social and political realities often require the use of power and coercion to achieve justice, as moral appeals alone are ineffective in changing the behavior of powerful groups. While advocating for social reform, Niebuhr acknowledges the limitations of human nature and the inevitable conflicts that arise in politics. His work highlights the tension between ethics and realpolitik, influencing later discussions on political realism, social justice, and Christian ethics.