Grotius on the Use of Force: Perfect, Imperfect and Civil Wars. An Introduction

In both of Hugo Grotius’s major forays into the law of nations, the just war doctrine provided the backbone of the argument. Between 1604 and 1606, Grotius prepared a treatise in defence of the capture of the Portuguese ship Santa Catarina in the Strait of Singapore by a fleet of the Dutch East India Company. In the text, which became known as De iure praedae commentarius upon its publication in 1868, Grotius refashioned the just war doctrine in order to argue that the captured ship and cargo were good prize in a just war. According to Grotius, this was the case regardless of whether one considered the Company an agent of the Dutch Republic in a war between states, or a private actor. With his idiosyncratic reading of the just war doctrine, Grotius wanted to respond to the obvious contention of the Republic’s Iberian enemies that the Dutch Republic, or the States of Holland whose agent the Company was, was a rebel force and lacked the authority to wage war. When Grotius returned to the theme of just war two decades later in De iure belli ac pacis libri tres (1625), he did so in the context of his construction of a general theory of the role of law – natural law as well as the volitional law of nations – in relation to war and peace-making. Grotius used the classical doctrine of just cause, in combination with the scheme of private rights and remedies of persons, property, contracts, debts and punishments, to structure his elaborate expositions of natural rights and obligations of both people and states. This scheme he took, in all probability, from the re-systematisation of Roman private law that the French humanist jurist, Hugo Donellus (1527–1591), professor at Leiden University, had proposed on the basis of the Institutes of Justinian.1 Although the purpose and logic of systemisation of the two works were very different, Grotius did draw