This chapter investigates Grotius’s broader intellectual involvement with the doctrine of predestination. Grotius deliberately renounced the religious importance of predestination as he called for religious concord in a time of fierce inter-confessional strife in the United Provinces - an endeavour that almost cost him his life. Considering his abhorrence for religious dogmas about divine predestination and human free will, two of his writings, Meletius and Ordinum pietas, display a remarkable restraint on Grotius’s part on the matter. Social and political order was not to be found in unrelenting dogmatic questions of certainty about what Grotius’s viewed as theologically non-essential religious principles. Rather it required a commitment to religious toleration. This chapter argues that Grotius’s involvement in the Dutch predestination debates reveals important philosophical connections between his religious and political ideas and allows for further explication of two central aspects of Grotius’s political theory: natural sociability and the impious hypothesis. From a careful contextualisation of predestination in Grotius’s religious oeuvre, emerges an account of socialisation independent of the predestination question, and establishes the infamous ‘etiamsi daremus’ statement as an obligation device that served his pursuit for religious and political accord.

Vattel stands among the principal jurists of modern international relations. Yet the balance of power – a policy at the heart of the theory and practise of international relations, and which Edmund Burke, for example, declared central to the ‘common law of Europe’1 – hardly figures at all in Vattel’s magnum opus. The question thus arises: why does it play a relatively insignificant role in his writings, and what role exactly does he think it plays? There is no doubt that he recognises it as an important element of policy in European relations. While the condition of a balance of power ideally maintains peace and harmony among states, it also carries within itself a powerful justification for preventive war. Balance of power is defined by the principle of collective security that prevents any states from attaining a preponderance of power and constituting a danger to the rest. Yet while this dynamic may ultimately limit the occurrence of war, as just war theory more generally seeks to do,2 any attempt to wage war to preserve the balance of power is predicated on the institutionalisation of war as an instrument of policy. Vattel is thus sceptical of its efficacy as a reliable mechanism for the limitation of war. Whoever ‘entertains a true idea of war … and considers its terrible effects’, Vattel writes, would surely agree that it should not be undertaken unless for the best of reasons (LN, III-iii-24).