Relations between social theory and natural law have not figured prominently in scholarly debates, and the case for their interconnections, which is far from self-evident, needs explicit justification. The aim of this special issue, which is to explore linkages between social theory and natural law, requires that we take a step back and redefine the ways in which these traditions are conventionally viewed. We see natural law as a heterogeneous intellectual tradition whose core lies in the question of universalism. We can differentiate between traditional and modern, conservative and radical, religious and secular forms of natural law, as well as between natural law and natural right; but in all cases the problem of universalism remains central. We see social theory as a modern intellectual programme that, over the past two hundred or so years, has sought to understand the rise and main features of a number of socio-historical trends that still very much configure the world in which we live: capitalism, democracy, the international system of states, and the differentiation of spheres of social life. The history of social theory’s relations to natural law builds on a distinction between the difficult but often intimate relation to natural law that social theory has actually experienced, and secondary reconstructions of social theory that read as if social theory has definitively moved beyond natural law and established in its place a scientific perspective. Our special issue confronts the latter view by explicitly addressing their interconnections.