This article has two primary aims. The first is to clarify the differing rationales for affirmative action that have emerged in five nations—France, India, South Africa, the United States and Brazil. The second is to make the case for the most compelling rationales, whether instrumentally or morally based. The author offers philosophical analysis of the justifications for affirmative action in each country and synthesizes federal and state legislation, court decisions, news media sources, and research-based scholarship.