This book traces the emergence of a sense of kinship with and belonging to a larger, more inclusive world within the law and literature of late seventeenth-century Puritanism. Connected to this cosmopolitanism in part through travel, trade, and politics, late seventeenth-century Puritans, it is argued, were also thinking in terms that went beyond these parameters about what it meant to feel affiliated with people in remote places—of which the Ottoman Empire is the best, but not the only example—and to experience what Bruce Robbins calls “attachment at a distance.” In this way Puritan writers and readers were not simply learning about others but also cultivating an awareness of themselves as “stand[ing] in an ethically significant relation” to people all around the world. The underlying source of these cosmopolitan predilections was the law, specifically the law of nations, often considered the precursor to international law. Through the terms for sovereignty, obligation, and society made available by a turn toward the cosmopolitan within the law, the Puritans experimented with concepts of extended obligation and ideas about a society consisting of all humans, not just those living on certain trade routes or within certain foreign communities. In mapping out these thought experiments, The Puritan Cosmopolis uncovers Puritans who were reconceptualizing war, contemplating new ways of cultivating peace, and rewriting the rules for being Puritan by internalizing legal theories about living in a larger, more inclusive world.