Although the study of citizenship has been an important development in contemporary sociology, the nature of rights has been largely ignored. The analysis of human rights presents a problem for sociology, in which cultural relativism and the fact-value distinction have largely destroyed the classical tradition of the natural-law basis for rights discourse. This critique of the idea of universal rights was prominent in the work of Marx, Durkheim and Weber. However, recent developments in the organization of nation states, the globalization of political issues, the transformation of family life, and changes in medical technology in relation to human reproduction have brought the question of human rights to the forefront of social and political debate. The paper argues that a sociology of rights is important, because there are obvious limitations to the idea of citizenship, which is based on membership of a nation state. Existing conceptualizations of citizenship require the supplement of rights theory. It is argued that sociology can ground the analysis of human rights in a concept of human frailty, especially the vulnerability of the body, in the idea of the precariousness of social institutions, and in a theory of moral sympathy. These three analytical supports – ontological frailty, social precariousness, and moral sympathy – are partly derived from the philosophical anthropology of Arnold Gehlen, from Ulrich Beck’s concept of the risk society, and Max Scheler’s phenomenology of sympathy. Embodied frailty is a human universal condition, which is compounded by the risky and precarious nature of social institutions. Human vulnerability can be contained or ameliorated by the institution of rights which protect human beings from this ontological uncertainty. From a sociological perspective, rights are social claims for institutionalized protection. However, it is because of collective sympathy for the plight of others that moral communities are created which support the institution of rights. This thesis not only offers a sociological version of traditional notions of natural or inalienable rights, but also attempts to provide a sociological alternative to enlightenment theories of social contract and individual rights.