The present study is a comprehensive overview of Kant’s contributions to international law. Combining both historical interpretation and systematic analysis of the relevant notions and assumptions, Corradetti’s work is remarkable in straddling these competing foci while offering a plausible interpretation that is both philosophically interesting and useful, regardless of whether one’s interest in Kant’s theory is systematic or historical. Furthermore, the work not only gives a clear systematic analysis of Kant’s political philosophy, but also grounds this analysis in Kant’s theory of judgement, as we know it from the Critique of Pure Reason and other parts of Kant’s writings that are not primarily concerned with questions of legal and political philosophy. In the following, I will consider these elements in turn.
The historical dimension of Corradetti’s study may be the strongest element of the entire book, as it works to frame the other elements of the interpretation. Furthermore, rather than just situating Kant’s work within eighteenth-century debates on international law and politics, Corradetti casts a wider net to include important debates from the sixteenth century as well. Furthermore, Corradetti not only examines how these debates unfold dialectically over time, but also considers how these debates respond to and intervene in historical events.
The book develops themes and problems posed by two concerns that Corradetti argues Kant inherits from his predecessors: the debates in international law precipitated by the discovery of the Americas in the fifteenth century, and the projects for an international legal system in the modern period that were aimed at preventing war, namely, the proposals for ‘perpetual peace’. These then foreground Corradetti’s interpretation of Kant’s methodology for determining principles and rights within international law.
With regards to the change brought on by the discovery of the Americas, Corradetti effectively starts by situating Kant’s political philosophy in relation to the concept of ‘global authority’. The foundational problem of European legal and political philosophy in this regard was how one should conceptualize and treat the newly discovered territories and peoples. The legal-conceptual challenge was primarily a problem for the exploring, and later colonizing, powers in how they could justify imposing their authority on the people who inhabited these territories. Where international law had previously been determined to a large extent by religious considerations, as belonging to the community of believers conferred the legal status of personhood and associated rights, encountering humans in these new territories for whom the Christian faith was wholly unknown posed a problem in applying old categories, primarily notions like terra nullius, for the sake of establishing sovereign control. While some figures like Francisco De Vitoria (1483–1546) can be said to have made important steps towards reformulating the foundations of international law so as to allow for the acknowledgement of the authority of individual states as deriving from a ‘global commonwealth’ (pp. 27ff.) rather than through a succession from legitimate emperors or popes, there were also clear limitations in the old natural law framework of treating ‘barbarians’ according to the Aristotelian category of natural slave, which was subsequently applied to the colonized peoples of the Americas. While this attribution did not go uncontested, as Corradetti highlights in his discussion of the debate at Valladolid of 1550–1, it would still take time to develop a less prejudicial way for treating people from significantly dissimilar cultures.
The second strand that Kant inherits from the tradition is the various projects and proposals for an international legal body that would enable legal-juridical procedures to replace war as a means of settling differences between states or advancing political goals. Corradetti identifies the beginning of such projects for internationalist pacifism with Erasmus’ The Complaint of Peace (1521), and highlights that Kant intervenes at a stage where there had already been numerous contributions to specifying the form and scope of this idea. While the origins of this idea are traced to a unified religious foundation of Christian brotherhood (e.g. Erasmus), a survey of the history of the topic reveals a variety of foundations, from a quasi-constitutional framework to a cost-benefit analysis of a federal agreement of European peoples. The texts of the Abbé de Saint-Pierre constitute perhaps the best-known predecessor to Kant’s own contributions on the topic, which Corradetti highlights had already been criticized by Rousseau as being perhaps too optimistic in grounding the pacifist arrangement on self-interest. The most important figures Kant positions himself against, Grotius, Vattel and Pufendorf, are all famously cast as ‘sorry comforters’ in Kant’s Towards Perpetual Peace. None of them can foresee an international order with legitimate coercive powers to prevent war, while precisely Kant lays the foundations for such an order.
This historical background allows Corradetti to lay out what Kant’s own contributions are to these discussions. Fundamentally, Kant’s method is characterized on the one hand by the regulative use of the idea of a world state to determine what principles should govern the interaction between states, as well as applying moral-rational principles in the interpretation of history to show the possible paths of development towards the realization of this idea. While regulative principles, as applied in theoretical investigations, apply a focus imaginarius to phenomena in order to be able to unify them according to the various theoretical interests that we have (unity, simplicity, etc.) so that we can systematically organize the objects of experience, when we apply these in the political context, we are guided by slightly different concerns. On the one hand, we take as an experiential (or as Corradetti puts it, a ‘phenomenological’) datum the collection of actually existing states in the world and the way they actually relate to each other; on the other, the idea of the world state/republic, conceived of as a global federation of states, imposes a normative standard for how we may judge how the actual existing system of political states ought to behave so as to realize the various demands that our notions of justice impose on us as practical agents.
From this standpoint, Corradetti firmly locates Kant’s legal and political thought within the critical framework of Kant’s better known works, i.e. the Critiques, as a question of reconciling ‘nature and freedom, that is, between the deterministic causality of nature and the unconditioned causality of the free will’ (p. 100). Furthermore, Kant’s political philosophy is also placed within Kant’s moral philosophy broadly construed. While at first glance it may seem that this would offer an overly moralizing interpretation of Kant’s writings on international relations, Corradetti is much more pragmatically minded (in both the ordinary and the Kantian sense of the word). In fact, the guiding notions of a world state in perpetual peace are perhaps impossible to realize in actual experience, given that these ideas can at best only provide standards by which we can approximate the ideal political situation. Nevertheless, as this idea occupies an action-guiding rather than an action-determining role, we can see that Kant’s political philosophy here only reflects his moral concerns, insofar as the political philosophy is an extension and reflection of the ideals of moral freedom.
Finally, Corradetti interprets Kant’s methodology as fundamentally following a constructivist procedure for deriving how one may arrive at a condition that guarantees peace and justice from relatively basic notions (like the right to visit from Toward Perpetual Peace or the original community from the Doctrine of Right). This allows him to situate Kant’s philosophy as a form of legal constructivism, which starts by identifying the formal conditions in which finite rational agents can act under conditions of freedom and equality and proceeds to specify how these could be realized. The constructive procedure comes into play, according to Corradetti, by identifying how one can justify coercive legal measures within the civil condition from those basic principles of right that all agents can be said to agree on within an initial condition of freedom. Crucially, this involves both an examination of what the legal order between states is supposed to be, as well as a consideration of how such an order can guarantee such individual rights as the right to visit. The constructive procedure thus allows us to conceive of how a constitutional regime can first be established on a domestic level, which is still considered the natural place to locate coercive legal powers, and to extend it further to an international setting.
In sum, this book is a valuable contribution to the current Kant literature for researchers interested in questions of Kant’s cosmopolitanism and constructivism in legal theory as well as teachers looking for a resource to contextualize Kant’s writings against the historical background of natural law theory, particularly with regard to the question of how modern debates around the status of indigenous peoples should be addressed, either when researching or teaching this material. Given the short length of the book, one cannot fault it for either not covering more of the historical background of Kant’s writings, or engaging more deeply with current debates.
However, a few questions did suggest themselves with regard to the material treated. Regarding the historical background, the book offers a valuable perspective on how colonialism and European imperialism shaped the foundations of Kant’s legal thought. One wonders what, if any, perspective Kant’s thought might have had in the face of states resisting any constitutional foundation of their domestic polities (such as the examples of Russia or the Ottoman Empire during Kant’s lifetime) interfering in the stable and peaceful relations between states that could at least be said to be ‘on the way’ towards an international civil condition. While Kant certainly thought that the question of perpetual peace could be solved by a ‘nation of devils’, it is still an open question whether a lasting peace can be achieved if one or multiple actors persistently resist aligning with such a generalized order. While it is an intellectual curio to determine whether Kant would have anything to say about ‘rogue states’ or ‘hegemons’ in his own lifetime, these questions are more pressing in our own time in terms of maintaining an international system of ever-growing importance.
Corradetti’s book achieves its goal of laying out a historically informed interpretation of Kant’s writings on international law while defending a constructivist approach to justification of basic norms and their extension to a generalized framework. However, it is not clear whether this interpretation can adequately bring this philosophical framework to bear on contemporary problems in international relations. While the problems we confront today are quite different than the ones Kant tried to address, due to the relatively increased complexity of international organizations, one might wonder how one can apply this framework to describe and address them, rather than retreading variations on the problems that Kant confronted in the late eighteenth century.
