This paper considers normative questions about the integration of legally resident immigrants into contemporary liberal democratic states. First, I ask to what extent immigrants should enjoy the same rights as citizens and on what terms they should have access to citizenship itself. I defend two general principles: (1) differential treatment requires justi.cation; (2) the longer immigrants have lived in the receiving society, the stronger their claim to equal rights and eventually to full citizenship. Second, I explore additional forms of economic, (...) cultural, social, and political integration. I argue that the integration of immigrants depends upon a process of mutual, but asymmetrical adaptation and that it is precisely because the immigrants have to adapt more that the receiving society bears a greater responsibility to take steps to promote equality between the immigrants and the existing population. (shrink)