Timely lessons for today's health and climate crises rooted in the origins of a government's provision for the common good The question of whether a government should take care of its people—preparing and investing in public health, welfare, and resilience policies—is arguably more important today than ever, as the world faces unprecedented climate and health crises. Commonwealth's exploration of the Venetian Republic, one of the oldest and most enduring republics in history, establishes for the first time that Venice and its constituent republics developed welfare policies not in response to the Plague, as is commonly thought, but two centuries earlier. Alexander More reveals that the lawmakers of Venice took advantage of its historic economic revival not to profit personally but to provide free medical care for their people. The Republic also inspected and guaranteed the quality and availability of food, water, and medicine, even when sudden climatic changes caused harvests to fail and supply chains to shift. Through original archival research in multiple languages, More shows that the welfare state of the Venetian Republic, from which our modern system is derived, took shape through deliberate efforts to work toward the common good. Readers interested in the history of medicine and public health, food security, welfare, climate science, and law will benefit from new insights into the origin and nature of commonwealth in society.