As usually defined, the concepts of justice and mercy seem incompatible' if justice is the strict application of the law, and mercy lenient deviation from it, then mercy is unjust and justice is merciless. Perhaps for this reason, liberal political philosophers have mostly neglected the topic of mercy, despite its traditional role in contributing to political stability. The present study suggests that one can integrate mercy into liberal political philosophy only after significant departures from the usual accounts. St. Anselm of Canterbury gave the classic formulation of the paradoxes of justice and mercy in his Proslogion, and in his later works he solved them. Anselm claims that justice and mercy should be defined in terms of right order or rectitude. Justice is the desire to effect and preserve rectitude, while mercy is the attempt at restoring another to justice so defined. Anselm claims it is both more stable and more humane to persuade people to desire right order for its own sake, rather than to coerce the people to uphold the political order or to bribe them to pursue it out of momentary advantage. Mercy, understood in an Anselmian fashion as ordered toward rectitude, is a stabilizing policy when exercised with prudence. The contractarian theories of justice promoted by John Rawls and others are unstable because they cannot earn the support of people who reject autonomy as the organizing principle of their lives and politics. Moreover, it is difficult to develop an adequate account of criminal punishment that is consistent with contractarian liberalism. A view that puts stability and mercy at the center of its accounts of governing and punishing can serve as a more stable foundation for liberal politics than can contemporary views. The theory developed here sees citizens a in democracy as leaders responsible for promoting their ideas of social order. When advocating their ideas, they ought to persuade those who disagree rather than to coerce them, for this promote stability. Likewise with criminals: although, punishment is justified as a defense of societal order against the criminal's attack on it, it is better to persuade the criminal to obey the law voluntarily and for principled reasons.