 That there are overlapping territories between public health, clinical care and biomedical science is, of course, to be expected as these enterprises are all committed to advancing human health. The major challenge is to answer the question of how broadly or narrowly to understand what public health entails. Given a wide understanding of health and the factors affecting prospects for population health, public health can be viewed as being so expansive as to have no meaningful institutional, disciplinary, or social boundaries. Everything from crime, war, and natural disasters; to population genetics, environmental hazards, marketing and other corporate practices; to political oppression, income inequality, and individual behavior has been claimed under the rubric of public health. Although all of these threats to human well-being affect health, it would be hard to conceptualize public health as encompassing all of the societal resources that these threats demand for their mitigation. For example, while reducing violence is critical to population health, that does not mean that law enforcement, the criminal justice system, diplomacy and international relations should be considered tools of public health.