Fifty essays on the state of population health from a vanguard voice in the fieldPublic health can rightly claim its share of victories: healthier cities, widespread sanitation, broader availability of nutrient-rich food, and reductions in violence and injury. But for all these gains, today we face a new set of challenges, ones complicated by political and professional shifts that threaten to fundamentally change the health of populations. Healthier is both an affirmation and an essential summary of the current challenges and opportunities for those working in and around the improvement of population health. The essays contained here champion an approach to health that is consequentialist and rooted in social justice -- an expansion of traditional, quantitatively motivated public health that will both inform and inspire any reader from student to seasoned practitioner. Galea's cogent, incisive arguments guarantee that his perspective, currently at the forefront of public health, will soon become conventional wisdom.