Bernard Williams articulated his later political philosophy notably in response to Ronald Dworkin, who, striving for coherence or integrity among our political concepts, sought to immunize the concepts of liberty and equality against conflict. Williams, doubtful that we either could or should eliminate the conflict, resisted the pursuit of conceptual integrity. Here, I reconstruct this Dworkin–Williams debate with an eye to drawing out ideas of ongoing philosophical and political importance. The debate not only exemplifies Williams's political realism and its connection to his critique of the morality system. It also illustrates the virtues and hazards of contemporary efforts to ameliorate or engineer our concepts; it indicates what political philosophy might look to in appraising political concepts; it adverts to the different needs these concepts have to meet if they are to sustain a politics of pluralism, deal with polarization, and secure the consent of those who end up on the losing side of political decisions; and it presents us with two starkly contrasting conceptions of politics itself, of the place of political values within it, and of our prospects of reducing the uncomfortably conflictual character of those values through philosophy.