Abstract: The modern world is legalized: legal language, institutions, and professionals are everywhere. But what is law’s power in global life? What does all this legality have to do with hegemony, with hierarchy and inequality, and with the diversity of human experience? What is its history and how does that history matter in world affairs? Above all, what does it mean to think “critically” about law and global affairs? In this poignant and iconoclastic book, two leading scholars take us to the heart of the matter, examining law’s relationship with history, power, and political economy. David Kennedy and Martti Koskenniemi have often inspired each other and are both considered “critical” voices in international law, but they have never explored their similarities and differences as deeply as they do here. Of Law and the World takes the form of a conversation, as the authors reflect on the study of international law, the motivations underlying their research, and the payoffs and limitations of their investigations into law’s role in global affairs. They revisit and renew debates about the past and future of the many legalities that shape our world. Erudite, open-minded, and informed by decades of experience and observation, Of Law and the World is an unflinchingly honest confrontation with humanity’s struggle to live together.