The author's primary aims are to clarify the differing rationales for affirmative action that have emerged in five nations--France, India, South Africa, the United States, and Brazil--and to make the case for the most compelling rationales, whether instrumentally or morally based. She examines the different social contexts surrounding the establishment and public discussion of each nation's policy. Next, she examines four justifications for affirmative action in these nations: remediation, economics, diversity, and social justice. She 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. She argues that the social justice rationale ought to be invoked more centrally, underscoring affirmative action's role in fostering a democratic society. (Contains 3 tables and 14 notes.)