Population health and health inequalities are best conceptualised in a complex systems model with interdependent elements at various levels within a connected whole. This perspective suggests that wide effects on health, such as socioeconomic, cultural, and environmental factors as well as social, behavioural, and biological effects, interact in generating population health outcomes. Debate has focused on an oversimplified argument pitching so-called upstream approaches against so-called downstream approaches, thus calling for a shift of focus and funding from individual-level approaches to population-level approaches. We argue that this distinction between approaches is based on a false dichotomy. Movement of resources from one level to another will not promote the science and practice of public health. An ambitious agenda should be embraced through the study of the interaction of multiple levels within systems relevant to population health.