of Kant’s philosophy is to be found in his moral and political works. The main task of the Critique of Pure Reason is to clarify its concepts and to get rid of basic errors, and is thus predominantly ‘negative’ (III, 43). The moral and political writings, on the other hand, try to expand the scope of reason ‘for practical purposes’ (‘in praktischer Absicht’; V, 134–41; VIII, 18–19). Establishing principles of moral and political conduct is not negative, but constructive. Thus Kant’s normative theory of international relations, or his philosophy of international right, is part of what he calls ‘doctrine’. My argument is that Kant goes beyond his understanding of ‘critique’ and ‘doctrine’ as developed in the first Critique in his political and legal writings of the 1790s, by adding an additional element: the attempt to mediate between the doctrine and its application in practice.
Many interpreters have written about Kant and his ‘philosophy of peace’; most of their publications are essays. Interpretations by international lawyers are very rare. This book focuses exclusively on Kantian international relations theory; it does not treat it as a mere appendix to state right. I think this is one of the first full-length analyses of its kind in English. It faces many challenges. One of them is mentioned by Kant in his preface to The Metaphysics of Morals (1797). Kant admits that he has treated ‘some sections’ towards the end of the book less intensively than previous ones, above all because he thinks that these later sections can easily be deduced from the previous ones (VI, 209, 8–11). These later sections are those devoted to international and cosmopolitan right. The task of concluding from previous sections is certainly not an easy one. We can see this when Kant writes about analogies. For instance, Kant claims that states or peoples (Staatsvölker) can be dealt with like individuals in a legal theory (VIII, 349, 16–17 and 354, 3–5). In another passage, Kant denies this domestic analogy or parallel (VIII, 355, 33–356, 1). We will discuss this in greater detail in Chapter 8.
In the central chapters of this book (chapters 3, 6, 7, 8), my starting points are apparent contradictions in Kant’s writings. Kant sees antinomies in metaphysics as a challenge to revise our theories and conceptions. I was not satisfied with the simple conclusion that Kant is ‘contradictory’, ‘inconsistent’ or simply senile. Assuming that Kant is a systematic and profound thinker, I have tried to use these contradictions to discover Kant’s ‘deep structure’.
Chapter 1, ‘The Contemporary Context: Kant’s Judgement on Erederick’s Enlightened Absolutism’, argues that my overall thesis – that Kant’s political philosophy should be read as an attempt to mediate between theory and practice, between norms and the status quo – also works on the domestic level. There is a parallel between Kant’s treatment of Frederick’s rule and the way in which Kant deals with the idea of a federation of states, for instance. Both are seen as transitory but necessary stages in the historical development towards the ideal of reason. Kant interprets his own state, Prussia, as non-republican, but as capable and in the process of evolving towards republicanism. This section is historical, and argues that Kant was not far from what we may call historical truth. Kant was no idealist in the traditional sense, and he never lost contact with the real world.
The second chapter, ‘Kantian International Right: Background and Paradigm Shift’, offers an outline of eighteenth-century international relations and law, the theories of international lawyers and legal philosophers, and peace projects. Apart from Hobbes, three people are important for Kant: Saint-Pierre, Rousseau and Vattel. The outline serves as a background for Kant’s paradigm shift in international relations theory that takes place in three areas. First, Kant’s doctrine moves from the traditional focus on the right of war to the right directed towards peace. Secondly, Kant reinterprets the concept of state sovereignty as popular sovereignty. Finally, Kant undermines classical international law as almost exclusively centred on states with cosmopolitan right.
Chapter 3 (‘Judging War’) argues that Kant tries to bridge the gap between the imperative of practical reason (‘there shall be no war’) on the one hand and the realities of war and bloodshed on the other. Kant employs the faculty of reflective judgement, which declares that wars serve an indispensable positive function in the development of humankind. Thus Kant arrives at two mutually exclusive perspectives on war, one based on practical reason, the other one on reflective judgement. The philosophy of history tries to interpret history tentatively as a gradual approach or advance towards the ideals of reason.
Chapter 4 (‘Does Republicanism Promote Peace?’) shows that Kant argues on three different levels that the republican constitution might favour peace. The third level is probably the most interesting one. Following Rousseau, Kant maintains that in a true republic, the normative general will (volonté générale) prevails. If the general will is oriented towards the (benefit of the) political community, which is peace rather than war, then the general will coincides with peace. The more a political community reforms itself and moves towards a full realization of the general will and thus republicanism, the more peaceful it becomes. The final sections of the chapter argue that Kant developed what I call ‘dynamic republican cosmopolitanism’. It goes beyond the so-called democratic peace proposition endorsed by authors such as Michael Doyle, and claims that Kant envisioned a republic where the citizens cultivated their moral dispositions, their way of thinking and their cognitive capacities. The enlarged way of thinking of an enlightened public would accept that respecting international law, even if less than perfect, should not be contingent upon compliance of other states, that republics have a duty to reform themselves, but must never coerce others to do the same, and so on. In short, these republican citizens would arrive at conclusions very different from what many proponents of the democratic peace proposition suggest.
Chapter 5 (‘Non-intervention, Humanitarian Intervention and Failed States’) focuses on a controversial issue of today’s discourse in international theory and law. It raises the question whether Kant’s strict principle of non-intervention can be applied in practice, and guide politics. Can we ‘translate’ the duty of non-intervention 100 per cent into certain situations? Kant’s a priori principles of right should be regarded as formal and abstract, but not as empty. Consequently, they allow for some latitude in their application. I will argue that the principle of non-intervention is relative in the sense that it must be seen in relation to and within the context of the juridical quality of the international arena, as well as in relation to the juridical quality of a certain state.
Chapter 6 (‘Conflicts in Kant’s Account of the Right to Go to War’) attempts to explain why Kant’s philosophy of peace leaves room for a right to go to war. Kant points out that in a state of nature, states are entitled to go to war, but only if certain conditions are met. In addition, this entitlement is only provisional, and must be abandoned as soon as the international community leaves the state of nature or anarchy. Again, Kant tries to mediate between the demands of reason and those of politics based on experience. An unconditional veto against any right to go to war (including the UN Charter’s right of self-defence) would be utopian and counter-productive. Some states would fall prey to aggressive and powerful ones, even further destabilizing the precarious balance among states. On the other hand, this very state of nature should be abandoned. Kant tries to solve this dilemma with a short-term entitlement to go to war and a long-term duty to enter a lawful condition or a juridical state. In terms of Kantian thinking on the right to go to war, I contrast passages in the Metaphysics of Morals with conflicting ones in Perpetual Peace.
