The book Unity and Diversity in International Law largely reflects international lawyers’ uneasiness and discomfort with this conventional dilemma. The volume consists of the proceedings of an international symposium held in Kiel, Germany, in November 2004. The aim of the symposium was to “analyze and discuss whether, to what extent, and in what regard international law has indeed developed into separate areas of law, which are either in conflict with each other, have found different solutions to the very same question – or whether instead we can still refer to the very notion of ‘general international law’ as such.” In order to answer these important questions, the organizers have asked five scholars to prepare reports based on a common questionnaire in their respective field of expertise, namely the law of the sea, international humanitarian law and international criminal law, human rights, international environmental law and finally international economic law. Based on these sectoral studies, different scholars have then prepared cross-cutting reports on issues of sources, subjects, domestic implementation, dispute settlement and State responsibility, in order to show whether in the various areas divergent trends have emerged and, if so, to what extent. Following each cross-cutting reports are comments by leading international scholars.