This chapter introduces the context and objectives of the book. International criminal law is still a relatively new body of criminal law, that was constructed in a rapid transnational conversation. The time is ripe for careful systematic and normative evaluation of this corpus of law. For example, scholars have noted that some doctrines may contradict fundamental principles of justice that the system claims to uphold. The book proceeds in three steps: it explains a problem, it outlines a solution, and then it demonstrates the solution through application.

The first, preliminary, objective of the book is to demonstrate a problem. Namely, the book highlights the need for an additional type of reasoning in criminal law: ‘deontic’ reasoning, which is different from doctrinal or teleological reasoning, and engages directly with principled constraints such as the legality and culpability principles.

Second, the book outlines a method for deontic reasoning, and in particular for identifying fundamental principles. ICL poses several special challenges for identifying the appropriate principles. The book advances a liberal, open-minded, humanistic, and coherentist approach (and explains each of these features).

Third, the book dissects current controversies in command responsibility in order to demonstrate the method, its questions, and the insights it can generate.