This thesis critiques the notion of "ethical neutrality" in liberal political thought, particularly that of John Rawls. Its primary intervention is to propose an alternative account of the ethical basis of liberal democracy, drawing on John Dewey's pragmatism. As opposed to adopting a stance of neutrality on matters of value, this approach, which I term value-experimentalism, grounds the legitimacy of public institutions - and the comprehensive ethical judgments which they necessarily involve - on their openness to ongoing contestation. I conclude by defending this view as a fulfillment of, not a threat to liberal freedom.