Arguing that demographic thought begins not with quantification but in attempts to control the qualities of people, Human Empire traces two transformations spanning the early modern period. First was the emergence of population as an object of governance through a series of engagements in sixteenth- and seventeenth-century England, Ireland, and colonial North America, influenced by humanist policy, reason of state, and natural philosophy, and culminating in the creation of political arithmetic. Second was the debate during the long eighteenth century over the locus and limits of demographic agency, as church, civil society, and private projects sought to mobilize and manipulate different marginalized and racialized groups and as American colonists offered their own visions of imperial demography. This innovative, engaging study examines the emergence of population as an object of knowledge and governance and connects the history of demographic ideas with their early modern intellectual, political, and colonial contexts.