There are presently two main ways of writing the history of international law, one using the methods of dialectical philosophical history, and the other approach using the methods of contextual history and legal humanism. The central difference between these historiographies is that dialectical history treat norms as formal or ideal entities that govern the unfolding of history through their dialectical interaction with facts. Whereas contextual histories view the norms of international law as contigent historical facts, that is as products of particular treaty regimes, and hence incapable of orientating history towards any particular goal, such as a cosmopolitan legal community. In this lecture, Professor Hunter clarifies this relation by sketching an outline of the history of the dialectical history of international law, beginning with a brief discussion of the most eloquent and erudite of the modern dialectical historians, Martti Koskenniemi, before offering an account of the first emergence of dialectical histories of international law in 1840s Germany.