This article examines the concept of 'radical otherness' from the perspectives of John Rawls' political liberalism and Chantal Mouffe's agonistic pluralism, and studies the relevance of these approaches to contemporary citizenship education. In this context, the notion of 'radical otherness' refers to such ethical, political or religious doctrines that are incompatible with the basic principles of liberal democracy and thus present a potential challenge to democratic institutions. The article suggests that despite its recent popularity in political philosophy and theory of education, Mouffe's agonistic pluralism faces difficulties in providing an adequate response to the issue of accommodating radical others in contemporary democratic societies. As a rejoinder to the Mouffean approach to political education, the paper develops a view of citizenship education based on Rawls' concept of reasonableness, and the democratic principles associated with it. It is argued in the paper that these principles--reciprocity and the burdens of judgment--are constituent elements of the symbolic space required by democratic politics. The article further suggests, however, that to properly address the issue of radical otherness in contemporary democracies, the limitations of the Rawlsian approach must also be recognised. Accordingly, Rawls' theory needs to be complemented with a more critical understanding of the economic, social and political processes and mechanisms that currently create structural injustice and social and political inequality in contemporary democracies.