One of the tools in the toolkit of human rights protection is international criminal law. However, application of this body of law is generally limited to the most serious human rights violations: atrocity crimes. In her recent book, Shocking the Conscience of Humanity: Gravity and the Legitimacy of International Criminal Law, Professor deGuzman examines what it means for crimes to be so grave that they concern all of humanity. She shows that the concept of gravity remains highly undertheorized, and uncovers the consequences for the regime’s legitimacy of its heavy reliance on this poorly understood idea. She argues that gravity’s ambiguity may at times enable a thin consensus to emerge around decisions, such as the creation of an institution or the definition of a crime, but that, increasingly, it undermines efforts to build a strong and resilient global justice community. Having elucidated the consequences of the regime’s reliance on the ambiguous idea of gravity, Professor deGuzman suggests how gravity could be reconceptualized to take account of global values and goals in the various decision-making contexts …