This article analyzes the most influential weltanschauungen at play in the politics of immigration in Europe. I categorize relevant value judgments into what I, following Theodore Lowi, call "public philosophies." I highlight three competing public philosophies in the politics of immigration in Europe: 1) liberalism; 2) nationalism; and 3) postmodernism. Liberalism prescribes universal rights protecting the autonomy of the individual, as well as rational and democratic procedures (rules of the game) to govern the pluralism that inevitably results in free societies. Against liberalism, nationalism stresses community and cultural homogeneity in addition to a political structure designed to protect both. Rejecting both liberalism and nationalism, postmodernism posits insurmountable relativism and irreducible cultural heterogeneity accompanied by ultimately irrepressible political antagonism. I examine the three outlooks through a case study of the headscarf debate. The article concludes with consideration of how normative ideas combine with other factors to influence policymaking.