Social Structures is a book that examines how structural forms spontaneously arise from social relationships. Offering major insights into the building blocks of social life, it identifies which locally emergent structures have the capacity to grow into larger ones and shows how structural tendencies associated with smaller structures shape and constrain patterns of larger structures. The book then investigates the role such structures have played in the emergence of the modern nation-state.

Bringing together the latest findings in sociology, anthropology, political science, and history, John Levi Martin traces how sets of interpersonal relationships become ordered in different ways to form structures. He looks at a range of social structures, from smaller ones like families and street gangs to larger ones such as communes and, ultimately, nation-states. He finds that the relationships best suited to forming larger structures are those that thrive in conditions of inequality; that are incomplete and as sparse as possible, and thereby avoid the problem of completion in which interacting members are required to establish too many relationships; and that abhor transitivity rather than assuming it. Social Structures argues that these "patronage" relationships, which often serve as means of loose coordination in the absence of strong states, are nevertheless the scaffolding of the social structures most distinctive to the modern state, namely the command army and the political party.