Kant’s political philosophy is by now an established field of research with an ever-increasing number of publications devoted to it. Macarena Marey’s new book, the title of which in English is: Omnilateral Will and the Finitude of the Earth: A Reading of Kant’s Political Philosophy,Footnote ¹ offers a thorough and thought-provoking contribution to this field, with an emphasis on three interpretative claims: (1) all juridical normativity must emanate from a concrete form of omnilateral legislation; (2) present-day injustices, and in particular the asymmetry of power between richer countries of the Global North and poorer countries of the Global South, can be productively rethought through a Kantian idea of popular sovereignty; and (3) property rights remain illegitimate until a truly omnilateral and reciprocal public will is established. Two conclusions follow from these claims: first, that the current international order of post-Westphalian states will continue to reproduce unequal power relations unless inter-state normativity is reshaped by a principle of popular sovereignty; and secondly, that in order to bring about such a world, Kant can help.

Central to Marey’s argument is the idea that the legitimacy of any form of political authority depends on the interlocking between a notion of popular sovereignty on the one hand, and the requirement of an omnilateral legislation on the other hand. This relationship is one of mutual dependency: only if sovereignty lies in the legislative power of the people and without exclusion (omni = all), can a system of rights and duties be said to be genuinely legitimate, i.e. capable of embracing the political participation of all agents. This distinctive requirement of popular sovereignty and omnilaterality is what, according to Marey, makes Kant’s political philosophy a ‘critical-metaphysical theory’, aimed at the practical task of ‘diagnosing the injustices that exist in a violent and unequal world’ (p. 21). We can readily see how, for the author, an incursion into Kant for mere exegetical gains would not be enough. In contrast, it is a methodological commitment of the book to appeal to Kantian resources in order to raise a critical lens to our current system of transnational capital, a system promoted by states whose power is merely empirical and de facto and far from being de jure.

The critical task of the book is advanced by means of a defence of a principle of popular sovereignty. For Marey, a Kantian principle of popular sovereignty (PPS) would have the required normative power to contest the hegemony of current forms of internationalism, and to offer alternatives to the status quo. As a supra-positive, political principle, a PPS is responsible for evaluating whether the laws governing the three spheres of public right are equitable and just, and ensuring that the interaction between individuals and between states is not mediated by force and violence. As a supra-political principle, therefore, Kantian popular sovereignty also involves the idea that collective agents (communities, people with a common aim not bound by a shared charted territory) have a right to create those institutions that it judges just and equitable, given the particularities of their practical and material contexts.

Importantly for Marey, there are reasons why a Kantian PPS is both ‘Kantian’ and ‘popular’. Sovereignty is distinctively ‘popular’ on her account for two reasons: (i) sovereignty corresponds only to the legislative power of the people, and (ii) legislative power is not to be equated with mere ‘coercion (Zwang)’ understood as the monopoly of force, but rather it is a form of legislation that enacts the correspondence between rights and duties. Furthermore, what makes this supra-positive principle of popular sovereignty ‘Kantian’ is that, for Marey, all juridical normativity – i.e. all laws, institutions and the political interaction between free agents – ‘ought to be decided omnilaterally, which implies that the creation of a public will ought to be inclusive and reciprocal’ (p. 172). As I heard the author say once, this inclusive and reciprocal public will must reflect ‘the unity of non-exclusion’, namely a unity where plural forms of political agency can coexist. To be sure, I think there is ample space to disagree with her claim that juridical normativity, and specifically the legitimacy of property rights, have to be derived from an empirically concrete omnilateral will. Property rights and rightful relations both between agents and between states would all fall short of this ideal standard of legitimacy, something that is not the case in Kant, at least if we take a minimalist approach to his system of right. However, and as we will see below, Marey is arguing precisely for this conclusion: regardless of the letter of Kant’s works, there are defensible Kantian grounds to show that a commitment to popular sovereignty and to omnilateral legislation demand such a high standard of legitimacy.

In addition to the desideratum of omnilaterality, a Kantian principle of popular sovereignty must regulate both at the intra-state and inter-state level. In this sense, it is not enough to guarantee omnilateral communities at home: what Kant’s broad understanding of right as a condition at the domestic, international and cosmopolitan level teaches us is that our juridical interaction requires a guarantee against forms of inequality at all levels of right, both at home and abroad. The ultimate vision in Marey’s account is to put the Kantian concept of popular sovereignty at the centre of our reflections concerning the injustices of the international system. Unless transformed, this order ‘serves to benefit countries with high incomes, and to harm the rest of the world’, so the whole idea of sovereignty as such is reserved only for a few. Hence, sovereign equality ‘must become a necessary (but surely not sufficient) condition for a more equitable world’ (p. 172).

Two salutary innovations follow from Marey’s interpretation: first, this Kantian notion of popular sovereignty displaces the centrality of the state as the locus of our normative considerations; and second, it opens new conceptual doors for the advancement of more politically progressive models of interaction that can be sometimes blocked by the apparent systematicity of Kant’s own thought. In this sense, the book proposes an alternative to a statist reading of Kant’s political philosophy, by showing how political communities around the globe can (and must) have a say in the making of legislation, without them being represented by a de facto state. I should note that this politically progressive account starts from Kantian exegetical grounds, but progresses with the clear intention of going beyond Kant himself. True omnilateral legislation thus incorporates marginalized and politically oppressed communities in shaping the international system. As Marey writes: ‘International right can indeed be just and equitable only if sovereign equality among states becomes the protagonist in the creation of norms’ (p. 190).

This ideal normative picture is anchored in real, present-day concerns. The background reflections motivating Marey rest in a broader critique of new and emergent forms of economic and political imperialism. On the basis of economic and allegedly democratic considerations, so the argument goes, more powerful states seem to have a right to intervene in the sovereign affairs of other states, and conversely, these less powerful political communities end up consenting to international norms (particularly economic norms legislated by bodies such as the IMF) to which they have not participated in legislating. In contrast, a genuine system of right, guaranteeing sovereign equality among all states through the omnilateral creation of norms will, on the one hand, secure the autonomy of each political community against these forms of interventionism and, on the other hand, guarantee an international order where all states interact as equals, due to a balance not of power and force, but a balance between rights and duties.

One of the most radical theses of the book is the claim that the provisional nature of rights of ownership in the Kantian state of nature is provisional through and through. Unless such rights emanate from the legitimate source of an omnilateral will, property rights remain provisional and open to be contested. Since such a concrete and omnilateral will is absent in our world, we remain locked in a system of exclusion of the many by the few. It follows that, taking seriously the provisional nature of property right implies that these rights, as has been sometimes understood in the literature, are not in a sort of ‘waiting room’, waiting for their turn to be positivised and made peremptory by any political authority: their absolute character will depend on their being originated from an omnilateral and concretely reciprocal will. It is the logical conclusion of her argument, and Marey is here willing to bite the bullet, that until that day comes, all claims to property remain provisional, and hence, illegitimate. At this point, the reader should keep in mind the critical aim of the book – its intention to advance a substantive critique of present-day injustices – and how, from this perspective, concluding that all property rights remain illegitimate is a conclusion of Marey’s critique, and not necessarily an interpretation of Kant’s own views on the status of property rights. For Kant, coercible property rights are possible, and their legitimacy can be defended against a minimal set of conditions that do not seem to require an equitable system of right like the one Marey envisions.

For those of us who have benefited from Marey’s distinctive and polemical approach to Kant throughout the years, this book represents the result of her body of work dedicated to positioning Kant both in relation to the history of political thought and in relation to our present concerns as citizens of a broadly neoliberal, post-Westphalian world. This latter task is achieved in the book by uncovering, rather than deliberately hiding, the political deficits of some of Kant’s arguments, in particular Kant’s misjudgement of the relationship between economic independence and political participation. Though the book rejects attributing any label to Kant – as a liberal, a republican, a radical democrat, etc. – he can be cautiously interpreted as a ‘sovereign-popularist’. However, Marey insists that labelling Kant’s political theory is difficult partly because it is a sui generis theory, unique in its revolutionary potential to transform both the tradition of modern natural law and that of the social contract (pp. 33–5).

Ultimately, what Marey tries to capture throughout the seven chapters of her study is the political potential of the idea of popular sovereignty, as a means to ameliorate – and, ultimately, to eradicate – the injustices of a system of nation-states that negates the active and fully omnilateral participation of diverse political communities around the world. For Marey, Kant’s commitment to an omnilateral will should not be reduced to an ideal mark of all political authority; rather it should be assumed as the normative criterion against which we must evaluate, contest and transform the injustices of our existing practices and institutions. For these reasons, the book represents an important contribution to ongoing debates in Kantian studies, as well as to problems beyond Kant. The book leaves us with the hope of a kind of ‘political ethics’, one that is based on our unavoidable interaction as free agents in a shared and finite earth.