This account of state-systems, which derives not from theoretical models but from the study of state-systems that have actually existed, emphasizes their moral or normative bases. It argues that a system of states presupposes a common culture. The essays deal with the concept of systems of the state-systems of Hellas; Hellas and Persia; the geographical and chronological boundaries of the modern states-system; international legitimacy; and triangles and duels. An introductory chapter by Hedley Bull draws the essays together and provides an account of Martin Wright's life and thought.