The best known example in the history of international law might be the so-called domestic analogy. In natural law thinking, the rights and duties of individuals were transferred to the rights and duties behind states. But metaphors are more than analogies. If there is a family, who are the parents, and who are the children? And are the parents entitled to educate the children and, sometimes, even punish them? In this lecture, Milos Vec reconstructs critically the career and the function of the phrase the ‘family of nations’, and asks what implications such a metaphor has beyond concrete political arguments.