 As we noted in Section 1.1, a defining characteristic of public health is that it is committed to advancing health at the level of populations. Public health relies on aggregated measures of health to identify health deficits, set health policy priorities, assess the impact of interventions, and allocate resources. It is this reliance on aggregation that sets the stage for numerous questions of justice in public health, including perhaps most prominently tensions between egalitarian approaches to justice and efficiency-oriented utilitarian approaches.