In order to develop a deep and detailed reflection on global norms, international law scholars need to pay more attention to insights supplied by the discussions on the philosophical problem of universals. Using the examples of the discussion on universals in Leibniz and Hobbes, the paper demonstrates the importance of the philosophical problem of universals to discussions on the possibility of global norms. In particular, the comparative study of Leibniz and Hobbes demonstrates that a world divided in states mostly presupposes (...) a denial of universals and thus an impossibility of truly global norms. Although in such a world cooperation and agreement between states is desirable and possible, the resulting agreement does not reach the threshold of normativity required under this view. On the other hand, truly global norms become possible if one accepts the existence of universals following Leibnizian tradition. However, in this case, the nature of normativity changes. Moreover, while states do not need to disappear, their role changes significantly and the main unit of consideration becomes the individual human being. Under this view, a wide variety of actors at the international arena are accorded equal importance. Based on lessons learned from this discussion, the article demonstrates how the questions raised by an explicit inclusion of the philosophical problem of universals into debates about global norms have continuing relevance today. It also suggests some possible avenues for future research. (shrink)