Hugo Grotius (1583-1645), the Dutch jurist and philosopher, is a key theorist of the post-mediaeval state. According to Grotius, the state is not subject to any terrestrial superior, either political or ecclesiastical. His political writings develop the consequences of this condition including the construction of state authority in terms of 'natural rights', acknowledging the right to self-protection and the needs of individuals. A further development is the idea that the state is the instrument of justice beyond its own boundaries. He asserted that there were universal moral standards that could be used to judge questions of international conflict. This universal morality was based on two prinicples: that self-preservation is always legitimate; and that wanton injury of another is always illegitimate. [On this foundation, rules for reconciling conflict could be erected and the existence of civil society explained.] These views have characterised much political thought from Grotius' day to the present and have played their part in the history of international law. This collection of articles presents in chronological order the writings of 20th century authors on Grotius and covers such topics as the life of Grotius, the evolution of his ideas, his contribution to the theory of ‘natural law’ and his wider significance as a political thinker.