Disobedience is the true foundation of liberty. The obedient must be slaves.

The line frames liberty not as a gift granted by authorities but as something secured through principled refusal—especially when laws or commands violate conscience. It echoes Thoreau’s broader argument that moral responsibility can require noncompliance with the state, and that unthinking obedience trains people to accept domination. In this view, “disobedience” is not mere contrariness but an assertion of individual judgment against unjust power; the “obedient” become “slaves” insofar as they surrender agency and ethical discernment. The aphorism has been widely used to summarize Thoreau’s influence on later traditions of civil disobedience, even when the exact wording is not his.