would probably have agreed to the categorical imperative as a foundation of civil society. Imperatives of skill and maxims of prudence were the bases of Frederick’s Prussia. His subjects were used as mere means. Frederick did not call himself servant of the people, but of the state. The new and frightening element in Frederick’s rule was that he used himself as a means as well – he was willing to sacrifice himself on the altar of the state. Frederick exposed himself to death in battle on numerous occasions. As Kant and his contemporaries knew, Frederick in addition ‘kept a strong poison at hand, presumably so that if he were captured when he led his troops into battle he could not be forced to agree to conditions of ransom prejudicial to his country’ (VI, 423, 26–9). Kant was right that ‘mere pride’ (VI, 423, 26–9) certainly was not Frederick’s motivation. Frederick’s willingness to sacrifice even his life for the state is part of his concept of being ‘first servant’. Though Kant’s reference to Frederick in the Doctrine of Virtue is listed under ‘Casuistical Questions’, his point of view leaves no room for doubt. According to the standards of the categorical imperative, Frederick had no right to dispose of himself ‘as a mere means to an arbitrary end’, as this would mean ‘to abase humanity in one’s own person’ (VII, 423, 1–6).
We are now in a better position to understand Kant’s enthusiasm about the outbreak of the French Revolution. For Kant, the principles of the revolutionaries were, at least during the first, constitutional phase from 1789 to 1792, diametrically opposed to Frederick’s pragmatism. As early as 1790, Kant praised their ‘organization’ of the ‘entire body politic’ according to the principle of morality: ‘For in such a whole each member should certainly be not merely a means, but at the same time also an end’ (V, 375, note). This ‘organization’ was missing in Frederick’s Prussia. For that reason Kant sided with the revolutionaries, defended the principles he thought they cherished and supported the revolution even at a time when it became obvious that the revolutionaries had betrayed their own principles.
In his last letter to Frederick in 1778, Voltaire praised his former friend enthusiastically: ‘If only Frederick the Great could be Frederick the immortal!’94 Voltaire accepted that Frederick was not only a follower of the Enlightenment but also eager to continue and even intensify traditional power politics. Ultimately, Kant’s evaluation was more negative. In Kant’s deterministic philosophy of history, Frederick’s humanitarian reforms were based on self-interest, not on morality. In contrast to nationalist intellectuals in Germany after the Wars of Liberation (1813–15), Kant detested the Frederick of military aggression and of wars, the Frederick who repeatedly violated international law and right. Voltaire’s moderate approach and ‘appeasement’ was typical of an earlier generation of Enlightenment writers. Kant, belonging to the last generation, was no longer satisfied with a reformed system of absolutism.95 The ultimate goal was the ‘perfect’ republic, ‘governed by principles of justice’ (IX, 444, 33–4; XXIII, 342, 27–9), which was identical with representative democracy. Kant invalidated reformed, enlightened absolutism to a mere transitory phase in this process towards republicanism. Thus Kant did not compromise with the status quo, as has been claimed by various authors for the last 200 years. It is also unfair and misleading to argue that Kant was ‘a radical in principle’, but deeply ‘conservative in practice’, and that in the 1790s Kant’s ‘views on social and political change look back to the 1770s’.96
Frederick taught Kant many things: positively, the importance of legal order backed up by powerful force. Negatively, he taught Kant how not to conduct relations with other states, and how state aggression leads to continuous insecurity. I have argued before that Kant offers a convincing answer to two questions raised by historians of enlightened absolutism. Critical philosophy suggests that we can never resolve the disagreement over the motivation of the rulers. If we assume a deterministic perspective, then we should be fully aware of this. That is, we have to be conscious of the fact that it is merely a perspective. As for the problem of whether the ideas of the Enlightenment are compatible with despotic or authoritarian forms of government, Kant’s answer is a clear no. On the other hand, Kant’s evolutionary philosophy of history rejects the idea of utter condemnation. Perhaps we have to qualify the statement about Enlightenment being incompatible with despotism. There are many diverging definitions of the Enlightenment. It was not a monolithic cultural force, and almost any prominent representative had a different understanding of this movement. Only a minority saw popular sovereignty as an ultimate normative principle, and many, especially German Aufklärer, accepted absolute authority on pragmatic grounds or in principle.97 Thus it is better to say that for Kant, a major representative of the Enlightenment movement, enlightened absolutism was in principle incompatible with his understanding of enlightened political ideals, but acceptable for the time being.
2 • Kantian International Right: Background and Paradigm Shift
The eighteenth-century background
The 1990s saw an unprecedented boom of congresses, books and articles on Kant’s essay Zum ewigen Frieden (1795), his theory of international relations and doctrine of international right.1 While this part of Kant’s philosophy was often ignored in the past, it has gained more attention of late. In addition, it is also often highly praised. Michael W. Doyle sees Kant as ‘one of the greatest of liberal philosophers’; Daniele Archibugi calls the peace essay ‘the most … significant work of juridical pacifism’; Fernando Tesón believes that Kant’s accomplishment in international relations theory is ‘magnificent’; and Howard Williams and Ken Booth agree with Chris Brown that Kant is ‘the greatest of all theorists of international relations’.2
This chapter provides some background information of Kant’s theory of international right and its unique position in eighteenth-century Enlightenment thought. I start with an outline of so-called ‘international relations’ in Europe during Kant’s lifetime. European international relations of the eighteenth century are usually subsumed under the misleading heading ‘Westphalian model’.3 The congresses of Münster and Osnabürck, the first European multilateral diplomatic gatherings, produced the Treaties of Westphalia in 1648, which ended the Thirty Years War. The treaties did away with imperial (Habsburg) hierarchy within the Empire and attempts at European hegemony, ended papal influence in politics, and tried to resolve the ‘religious issue’ (the denominational disputes between Catholics, Lutherans and Calvinists). The congresses were one important step in a long-term process where the traditional imperial vertical model was replaced by the modern horizontal interstate model. For the major powers, sovereignty meant the right to go to war whenever it seemed appropriate. Eventually, namely in the nineteenth century, the sovereign state as the prototype of international actor evolved, with central concepts such as territorial integrity and non-intervention at its core. Classical European international law of the eighteenth century, often called ius publicum europaeum, was different. It gradually abandoned the just-war theory of the Middle Ages and focused instead on an elaborate doctrine of the right to make war. Modern European war between states was bellum iustum ex utraque parte, ‘just’ – or rather legitimate – on both sides.4 This ius ad bellum was rooted in the principle of sovereignty. War was the ultima ratio regum, the last means of the kings to pursue their rights if they believed they had been violated. In practice, it was up to the king alone to decide if a violation had actually taken place.5 Still, there was some sort of order and some community interest: ‘The Peace of Westphalia failed to establish a comprehensive order, but it did include some elements of a hypothetical international order.’6 In Kantian terms, the European countries had left the state of nature, but failed to enter a full juridical condition. Several wars were fought against Louis XIV from the 1670s onwards to check his alleged ambitions for a ‘universal monarchy’ and to keep an evolving and precarious balance of power.7 The peace settlements of 1713–15 did not modify existing arrangements. War was not seen as an inherent evil or as an endemic problem of the European order. The settlements were ‘a victory for the principle
