The Analysis of Thoreau and Martin Luther King Jr.’s Perspectives on Unjust Law

Abstract

Within discussions of legal philosophy, the enduring debate over the relationship between law and morality, centered on the proposition that "an unjust law is no law at all" (lex injusta non est lex), has remained one of the central issues in both theoretical inquiry and social practice. This paper takes the core viewpoints of Henry David Thoreau and Martin Luther King, Jr. on "unjust laws" as its research object, exploring the classic jurisprudential proposition of "whether an unjust law is truly law and whether it needs to be obeyed." The paper begins with an introduction to the differing stances on this issue held by the natural law school and the legal positivism school. It focuses on analyzing Thoreau's critique of the Mexican-American War and slavery in "On the Duty of Civil Disobedience," where he proposes the theory of "lex iniusta non est lex" based on individual conscience and practices tax resistance. Simultaneously, it examines Martin Luther King Jr.'s position in his "Letter from Birmingham Jail," written during his imprisonment for participating in nonviolent demonstrations against racial segregation. King inherited and developed Augustine's view that "an unjust law is no law at all" to confront systemic injustice like segregation laws, advocating for nonviolent direct action. The paper conducts an in-depth comparison of the commonalities and differences between their perspectives. The research indicates that their ideas profoundly influenced subsequent legal ethics, social movements, and legislative processes, jointly promoting reflection on the justice of law, the duty of citizen obedience, and the advancement of democratic legal change through peaceful protest. This provides significant insights for understanding the moral foundations and limitations of law.