a stream of letters to Brühl complaining of his ill health and dire financial circumstances. Nevertheless, this turned out to be the most productive period of his life. In 1757 he published a further collection of essays that included dialogues between Diogenes and Marcus Aurelius and between Henry IV of France and his adviser Sully.8 Also during this period he wrote his masterpiece, Droit des gens, which appeared in Neuchâtel at the end of 1757, though the title page says London 1758.9 The work quickly established Vattel as a major authority on natural jurisprudence.10 It also changed his personal situation. In 1759 the elector of Saxony finally recalled Vattel to Dresden, appointed him to the Privy Council, and made him chief adviser to the government of Saxony on foreign affairs. During his stay at Dresden, Vattel published two further works, Mélanges de littérature, de morale, et de politique (1760, reprinted in 1765 as Amusemens de littérature, de morale, et de politique) and Questions de droit naturel et observations sur le traité du droit de nature par le Baron de Wolf (1764), a detailed critique of Wolff’s Ius gentium methodo scientifica pertractatum that Vattel had completed already in 1753. In 1764 he married Marie de Chêne, the daughter of a Huguenot noble family, with whom he had a son. Due to ill health, Vattel was unable to cope with his office and retired to his native Neuchâtel, where he died in December 1767 at the age of fifty-three.
Influence of Swiss Heritage
Although a subject of the king of Prussia by birth, and a servant of the elector of Saxony by profession, Vattel was first and foremost Swiss. However, that description was more complicated in the eighteenth century than it is today. What foreign observers often referred to as the Swiss republic was in fact a loose federation of independent and highly diverse entities, some aristocratic, some democratic, some monarchical, all of them small, some no bigger than a town. The federation was held together by fear of foreign aggression, a complex web of treaties, jointly ruled territories, and military and trade agreements to contain conflict between individual cantons. Although Swiss thinkers frequently invoked a universal society of nations, they remained highly suspicious of projects for perpetual peace in Europe, whether a benevolent hegemony or a European federation. Instead, they saw their best chances of survival in the more fragile order provided by a balance of power between large commercial nations constantly in need of Swiss mercenaries for their armies and Swiss investments for their public coffers. Swiss attachment to state autonomy was so great that, during the 1750s and 1760s, a small but highly vocal minority flirted with Rousseau’s ideas of strict isolationism as the only way to defend Swiss liberty from the aggressiveness of modern commercial politics. Like Vattel, the majority of eighteenth-century Swiss thinkers, however, saw clear military and cultural benefits in commercial progress and ridiculed Rousseau and his followers’ infatuation with the alleged virtuousness of ancient Sparta.11 They hoped to adapt the humanist heritage of Swiss politics to the realities of a modern economy by showing how new forms of Christian patriotism, assisted by wide-reaching legislative reforms, were able to arrest and dissolve the dangerously “unsocial” tendency of commercial states.12
Vattel’s Theory of Natural Law as Applied to the Law of Nations
Against the background of this Swiss debate, we can understand not only Vattel’s vision of a workable European order but also the importance he attributed to political economy for establishing and maintaining a regime of international justice. In a famous passage, Vattel claimed that commerce had transformed Europe from a “confused heap of detached pieces” into a kind of large republic, where all members were united “for the maintenance of order and liberty” (bk. III, §47). An “eternal and immutable law of nature” obliged a state not only to respect and to treat other states as equals but also to provide mutual aid “so far as that other stands in real need of its assistance, and the former can grant it without neglecting the duties it owes to itself” (bk. II, §3). Here Vattel claimed to be following Christian Wolff who, in his Ius gentium methodo scientifica pertractatum, derived the duty to mutual aid from analogy between the state of nature and the realm of international relations: the law of nations was simply the law of nature of individuals in the state of nature applied to states (Prelim. §3–9). The primary duties of states were, first, to preserve and perfect themselves, and, second, to assist each other in fulfilling those duties each state owed to itself. States should “cultivate human society,” primarily through trade, as long as the development of commerce did not conflict with their primary duties to themselves. Vattel argued that states that acted upon the principles of natural law alone would ultimately come to form a universal republic: “A real friendship will be seen to reign among them; and this happy state consists in a mutual affection” (bk. II, §12).
Although Vattel claimed that this “delightful dream” was derived directly from human nature, in The Law of Nations he acknowledged that “most nations aim only to strengthen and enrich themselves at the expense of others” (bk. II, §16). Accordingly, prudence prevented existing states from making mutual aid the guiding principle of foreign politics. Instead, states ought to content themselves with a morally less appealing, but nevertheless workable, order based on the balance of power. Vattel explained this acknowledgment of the realities of modern European politics on two grounds. The first was the theoretical incoherence of previous natural law theories with regard to the duties of perfectly independent states. Here he turned against Wolff’s idea of a civitas maxima, as we will see.13 Vattel claimed that Wolff had rightly distinguished between two forms of the law of nations: first, an immutable or necessary law of nations, signifying the law of nature applied to individual states; second, a voluntary law of nations, which defined the necessary limitations of natural law within the realm of international relations and which, he argued, had to be tolerated in order to avoid greater harm.14 Although states, like individuals, were bound to assist others, this duty was limited by the perfect right of a state to self-preservation. The implication this had for trade was clear enough: while a state was obliged to trade with all other states and sell its products at a “fair price,” considerations of self-preservation allowed it to limit its trade, establish trading companies, or even refuse commerce with another state altogether. Wolff had also rightly recognized that since the law of nations applied to all states in the same way, those states affected by trade sanctions could merely point out breaches of the necessary law of nations. Refusal to trade, however, did not provide any legal ground for the commencement of military hostilities. The situation was different when a state was not just incapable of self-preservation but lacked any resources to exchange for vital goods. Here, the perfect right of preservation of a potential donor nation was bound to clash with the equally perfect right of preservation of a state on the brink of starvation. It is in this context that one needs to read Vattel’s often-cited justification of the appropriation of uncultivated land by European settlers in America.15
Given the increasingly economic dimension of European politics, there was a constant danger that peaceful trade would be subjected to the logic of warfare. Vattel’s main task in The Law of Nations was to define as clearly as possible the limits individual states were allowed to impose on freedom of trade. Wolff hoped to derive such understanding from the image of a civitas maxima, a universal republic instituted by nature, whose civil law was the expression of the right reason of civilized nations. In the preface, Vattel rejected Wolff’s civitas maxima as fictitious and incompatible with the idea of state sovereignty (preface, 14). While civil society could be said to be natural in that it originated in human need, no such thing could be said of the relation between sovereign states: “I acknowledge no other natural society between nations than that which nature has established between mankind in general” (ibid.). In contrast to individuals, nations enjoyed greater autonomy and because of this had no pressing reason to subject themselves to a higher authority. Furthermore, their absolute liberty was necessary “properly to discharge the duties [the state] owes to herself and to her citizens” (preface, 15).
Vattel’s defense of a natural law of nations together with his insistence on state sovereignty earned him a reputation for incoherence, the view of Kant, or, as many international law theorists writing after the First World War maintained, for being an unconditional supporter of reason of state who “disguised
