Kant’s domestic analogy: international and global order

Abstract

The domestic analogy is an old but persistent problem in theories of international politics. This paper examines the problem in the work of Immanuel Kant, whose political writings are often cited as a paradigmatic example of the analogy between individuals and states. Attention to Kant’s own conception of analogy, however, shows that the political writings are structured by another “domestic analogy”—between international and cosmopolitan right. This analogy, I argue, is based on a correspondence between the systematic unity of the international and the spherical globe, the figure that for Kant represents the boundaries of world order. International and cosmopolitan right are thus distinguished on the basis of a geopolitical criterion: the global scope of international order. This analogy of order, the paper argues, thus works to domesticate world politics through the structural form of international order. To the extent that contemporary theories of international relations rely on this conception of order, they accept Kant’s answer to the problem of perpetual peace. The paper concludes by drawing broader conclusions from the analysis about the domestic analogy, international order, and world politics.

The relationship between international and world order is being reconsidered across the human sciences in the context of ongoing patterns of violence and inequality and massive changes to earth systems linked to political and economic globalization. My analysis looks at one early and influential account of this relationship—Kant’s ideas about international and cosmopolitan right—through the problem of the domestic analogy. Kant’s theory of international politics is commonly read as a paradigmatic example of the domestic analogy, that is, the analogy between individuals in a pre-civil condition and states in an international system. On this model, the international system represents the problem of disorder to which cosmopolitan or global unity based on domestic institutions is the answer. Kant’s writings are ambivalent, however, about whether states and individuals can be considered analogous. Moreover, commentaries on Kant rarely consider Kant’s own conception of analogy or his claim in Perpetual Peace that cosmopolitan right can be understood by analogy with international right. Doing so, I argue, shows that Kant’s political thought is characterized not only by an analogy between individuals in a “state of nature” and states in an international system—but also by an analogy between international order, which Kant conceives as a system, and the globe, which Kant theorizes through the figure of the sphere. The analogous form of order displayed by both systematic unity and the figure of the spherical globe—a reciprocal relation between parts and whole—suggests a new formulation of the problem of the domestic analogy in Kant’s political thought.

This reformulation is consequential for debates on international relations and world politics today in several respects. First, the analogy between international and global order suggests that for Kant an international system of states is an answer to rather than an expression of the problem of the domestic analogy conventionally understood. The unity represented by the European system of states is for Kant the start of the historical development of a civil condition among states that will gradually encompass the whole earth. This analogy thus suggests, second, that international and cosmopolitan right are differentiated on the basis of a geopolitical criterion: the global scope of international order. Together, this means that a global international system—the starting point for theories of international politics today—is the telos of Kant’s developmental, universalising philosophy of history. For Kant, cosmopolitan political unity in the form of a global international system is the ultimate end of nature and of human political organization on earth. Kant’s analogy between international and cosmopolitan right thus indicates a domestication of world politics through the structural form of international order.

This has several implications for present-day debates on world order. First, it helps explain the ambivalences in Kant’s own work and the numerous commentaries on the domestic analogy in Kant’s political thought. The analogical relationship between systematic unity and the sphere shows how both the analogy between individuals and states and international and cosmopolitan right are part of a single universalizing philosophy of history that culminates in a global international system. This means that approaches that contrast a global or cosmopolitan order with an international one are unlikely guides for the future development of alternative forms of world politics, given the analogical relation between them in Kant’s work. Second, it suggests that critical engagement with Kant’s political thought requires greater analytical attention to the form of global order and unity that for Kant determines the boundaries of human political organization on earth. This is a geometrical ideal of order given in the figure of the sphere, approximated in the idea of systematic unity, and shared by a range of theories of international order that are otherwise at odds. Contesting the terrain on which these debates play out thus entails addressing the geopolitical dimensions of contemporary international relations, dimensions that express a particular relationship between the form of the earth and the potential for human political organization on a world scale. To the extent that contemporary theories of international relations begin their analyses from a global international system, they accept Kant’s answer to the problem of perpetual peace.

The analysis connects the problem of the domestic analogy to recent studies of Kant that focus on the significance of the spatial ordering of the planet for the problem of political authority on a world scale. As Mark Franke explains, for Kant the form of the earth is a key question because it determines the boundaries of human experience, reason, and by extension the practical possibility of a world political order. It is the analogical relation between the whole of reason and the whole of the world that leads Kant to suggest both that transcendental reason and the earth itself are best understood through the figure of the sphere (Franke, 2001: 128–134). The significance of the spherical globe for the political life of “man” and its relation to international order are evident in Kant’s theory of international and cosmopolitan right, which are, as both Kant himself and recent commentators affirm, inextricable from the geographical conditions of the earth. ¹ This work highlights the link between Kant’s theory of space and geography and his model of world-scale political order. Geographical conditions, Kant insists, cannot be known through world travel and empirical investigation. The most fundamental of these conditions is a “conceptual whole” (Kant, 2012 [1802] 447 [9:158]) as Kant explains in the Physical Geography, since “he who wants to profit from his journey must have a plan beforehand, and must not merely regard the world as an object of outer senses” (Kant, 2012: 445 [9:156]). This prior concept of the earth, according to Kant, is the figure of the geometrical sphere, which, as will be shown below, displays a kind of order analogous to the systematic unity that characterizes international order.

At stake in debates over the domestic analogy are the boundaries of world political order. In the case of Kant’s domestic analogy examined here, these boundaries relate to the way international order expresses a unity analogous to that of the spherical globe. It is with this form of unity that Kant, along with most theorists of international order today, marks the boundaries of world politics, boundaries that domesticate earthly political life within a specific structural form. While the international system is usually associated with mechanistic ontology and sovereignty, at the world scale political order is thought by Kant through an analogy of “nature” understood as a systematic unity. This enables a claim to political globalization—a world political order coextensive with the earth—that is the starting point for analysis of world politics today. Attention to Kant’s analogy between international and cosmopolitan right thus reveals a domestic analogy prior to that between individuals and states: a domestication of the earth through the structural form of a global international system.

Domestication and the domestic analogy

Although efforts to “domesticate” a supposedly disordered international politics in response to the lack of a common political authority to govern relations between states continue unabated, these are complicated by a range of scholarship that shows the way international politics is already characterized by ordered patterns and structures such as society (Bull, 1977) and hierarchy (Mattern and Zarakol, 2016; Zarakol, 2017). Though the problem of the domestic analogy is rarely considered explicitly in international relations theory today, the challenge the problem presents—of the “domestication” of political possibilities through specific accounts of political order at the local scale (i.e. state sovereignty)—is no less present in the way international system is theorized as a political order of global scope. Like in classic accounts of the domestic analogy in the case of the analogy between international and world order, a regionally and conceptually specific understanding of political order becomes a model for the entire planet.

The domestic analogy refers to the persistent tendency of theories of international politics to draw on models from domestic politics to govern relations between states. According to Hedley Bull (1995), one of its foremost critics, the domestic analogy is “the argument from the experience of individual men in domestic society to the experience of states, according to which the need of individual men to stand in awe of a common power in order to live in peace is a ground for holding that states must do the same” (p. 75). The domestic analogy, in this sense, consists of what is sometimes called the “state of nature analogy,” which is the view that the disorder that characterizes relations among individuals before the establishment of a sovereign authority is the same kind of disorder that reigns in relations between states (Jahn, 2000). These two dimensions of the analogy are closely linked. As Suganami points out, “the domestic analogy entered the theoretical discourse on international relations when sovereigns or sovereign states came to be regarded as coexisting in the pre-societal state of nature” (Suganami, 1989: 20). For proponents of the domestic analogy, then, because of the analogy between individuals and states in a pre-civil condition, the solution to the problem of order among states must be analogous to the solution to the problem of order among individuals proffered by the political theory of the state. This approach appears in both internationalist and cosmopolitan versions, the former which argues for preserving the states system while adding democratic norms and institutions modeled on domestic society and the latter arguing in favor of a world state (Suganami, 1989: 14). The domestic analogy in this sense is an attempt to bring order to what is understood as disordered, pre-civil relations between states.

What is at stake in the problem of the domestic analogy, according to Bull (1995), is the “autonomy” of international relations, the idea that international politics represents a sui generis order and thus cannot be subject to the same expectations dominant in analyses of domestic politics (p. 75). The limits of the domestic analogy that Bull aims to elaborate express the degree to which international politics are separate in kind from those that obtain within the state. The idea that the international and the domestic represent two distinct forms of order, however, has itself been subject to critique. By presuming the distinction between the domestic and international, Richard Ashley (1995) argues, both proponents and critics of the domestic analogy affirm the bounded, particular, domestic political order as the privileged site of politics and as the “possibility condition” of the sovereign figure of “reasoning man,” the idealized model of the human that grounds modern claims to truth (pp. 94–128). These discourses thus engage in a domestication of political possibility by affirming state sovereignty as an answer to the question of political order, rather than as the subject of scholarly analysis. The result of this domestication is that the states are “regarded . . . as the self-evident conditions of life on a global scale” and become part of “global processes of domestication” in which “knowledge practices . . . discipline the indeterminacy and equivocity of history, imposing structure upon it” (Ashley, 1995: 102). Even Bull’s critique of the domestic analogy, on this account, results in the universalization of the state as the proper form of political community.

Yet Ashley’s analysis does not focus on how “local” instances of domestication work as part of processes of global ordering. Ashley does not fully explore the relation between domestication and the international because of his equation of the international with the principle of state sovereignty. Like Bull, Ashley does not repudiate international anarchy but theorizes it as something other than an absence of order. By moving from the anarchy problematique to the sovereignty problematique, Ashley avoids a more detailed analysis of the way international order functions as a domestication of political life on a global scale. As Franke (2001) puts it, Ashley fails to “take into account the broader planetary territory from which the sovereignty of Kant’s rational human speaks the story of Man in nature” (p. 148). For Ashley, the foundational principle of international politics remains state sovereignty, and it is this principle that enables the process of domestication proper to International Relations. As such, Ashley treats the international as a global political order, but one that only consists of “local” instances of domesticating processes of political ordering.

In what follows, I show the way Kant relates a European international system and global cosmopolitan order by tracing an analogy of form between international and cosmopolitan right. This analogy, grounded in a concept of systematic unity, enables Kant to domesticate world politics within a particular set of boundaries. This is evident, for example, in Kant’s expectation in Idea for a Universal History, that the system of states developing in Europe “will probably legislate eventually for all other continents” (Kant, 1991 [1784] 52). The correspondence in form between international and cosmopolitan right constitutes its own form of domestic analogy through the way Kant analogizes between a particular form of political order (the European states system) and the world as a whole.

Kantian antimonies

Across international relations, intellectual history, political philosophy, and political theory Kant’s international political thought is understood to be organized primarily around the domestic analogy. Commentators otherwise at odds are united in understanding Kant’s formulation of the problem of international politics in terms of the view that relations between states are analogous to those between individuals in a “state of nature” and thus must be overcome by the institution of some form of civil society. This indicates how Kant’s work is mobilized to support of a variety of political purposes and is thus not reducible to a single position but a broad set of possibilities for world political order (Hutchings, 1995). A particular understanding of the domestic analogy in Kant’s work is mobilized in a wide range of conflicting theories of international politics which suggests that Kant’s formulation of the problem of world politics sets out the terrain on which key debates in the field play out.

While Kant is variously read “as advocating federalism, a world government, a League of Nations-type security system, and outright pacifism,” debates on these topics are split between what Hurrell calls the “statist” and “cosmopolitan” readings of Perpetual Peace (Hurrell, 1990: 183). Kant’s oscillation between hopes for the possibility of a cosmopolitan world order beyond the state and state-system and significant doubts about such a possibility lends itself to contradictory readings. While Kant is most frequently employed in support of liberal claims about a cosmopolitan world community, he is also read as a thinker who affirms the limits of sovereign states and the inevitability of violence among them. This double reading of Kant in international relations is by now quite familiar, and commentaries on the ambivalent way Kant has been taken up in the discipline now seem almost as common as interpretations that either affirm Kant’s account of the limits of the sovereign state or its transcendence (Bartelson, 1995; Franke, 2001; Hurrell, 1990; Hutchings, 1992; Walker, 2010; Williams, 1992).

The latter take Kant’s political writings to offer plausible solutions to the problems of conflict between states. Among these are scholars who argue that the positive link Kant draws between republican constitutions within states and peaceful relations between them is borne out empirically and thus works as a practical guide to the perpetuation of world peace (Doyle, 1983a, 1983b; Russett and O’Neal, 2001; cf. Jahn, 2005). Advocates of the peacemaking potential of inter-, supra-, and transnational organization for the promotion of peace similarly draw on Kantian political philosophy for inspiration (Archibugi, 1992). Others like Hedley Bull (1997) emphasize Kant’s conception of cosmopolitan right and its attendant focus on the individual as a ground for a peaceful world politics (pp. 24–40). Contemporary theorists of cosmopolitan democracy and world society, moreover, persist in employing Kant as a guide for their visions of world order (Linklater, 1998). For these scholars, the domestic analogy is a guide to overcoming the disorder of relations between states through the introduction of statist institutions.

As a second group insists, however, this is only one side of the story Kant tells about possibilities for peace on earth. F. H. Hinsley, for example, argues that Kant’s dreams for peace reach no further than a federation of states, one characterized not by substantive political unity, but by laws and institutions shared by sovereign states. Kant’s (1967) solution to the problem of international conflict is, in Hinsley’s view, to enable the constraining power of law absent a unified political order. Gallie (1978), likewise, argues that Kant, despite being “the first internationalist, was also one of the most steadfast ‘statists’ in the history of political thought” and the kind of federation Kant envisions is not a unified political order but a loose “confederation” or “partnership” limited by the principle of state sovereignty (p. 25). Kenneth Waltz, similarly, emphasizes the frankness with which Kant acknowledges the difficulties involved in imagining a peaceful international order given the “crooked wood” of human nature from which such an order must be crafted. On this reading, Kant is not a herald of peace but “gives us a deeper appreciation of the causes of war and the immense difficulty of doing anything about them” (Waltz, 1962: 340). For Hinsley, Gallie, and Waltz, Kant’s program for peace primarily indicates that any semblance of peace achieved among states will necessarily be hard-won, fragile, and precarious. These analyses emphasize Kant’s reliance on a Hobbesian theory of the state and state of nature in posing the problem of international and cosmopolitan right (Bull, 1977; Tuck, 2001). On these accounts, the domestic analogy represents the limits of schemes for world order expressed in the anarchical character of the international system.

Others read the tension between statist and cosmopolitan interpretations—as well as Kant’s own uncertainty regarding the fate of world politics—in the context of his critique of metaphysics. These emphasize how the structure of Kant’s philosophical system gives rise to the limits expressed in realist and idealist positions. On these accounts, the domestic analogy reflects the dualism expressed in Kant’s distinction between nature and freedom that structures the inevitably finite and conditioned character of earthly life. As Kimberly Hutchings (1995) explains,

Kantian critique is premised on both the limitation of reason and the assumption of the capacity of reason to transcend that limitation in the process of critique” and should thus be understood “as a paradoxical political practice rather than as a failed or successful metaphysics. (p. 1)

Jens Bartelson, for example, argues that the way reflective judgment manages the tension between nature and freedom (or understanding and reason) suggests that “the perpetuality of perpetual peace . . . [consists] . . . in the fact that the movement toward its realization is without end” (Bartelson, 1995: 276). The oscillation between war and peace and between international and world expresses a concept of the world—and by extension a world politics—as an ideal both necessary for the construction of international order and impossible to achieve. According to these scholars, Kant is a theorist of the ultimate inextricability of peace and war, violence, and progress.

Similar ambivalences are at work in debates over colonialism, race, and empire in Kant’s work. ² On the one hand, scholars point to the way that conceiving of international order in terms of a pre-civil condition among individuals masks the racial (Henderson, 2013: 71–92), civilizational (Valdez, 2019), and cultural (Jahn, 2000) hierarchies that characterize Kant’s political thought and international order today. For Jahn, the abstract, universalising character of the philosophy of history inaugurated by the analogy between individuals and states masks the fact of human cultural diversity. A philosophy of history that starts with the state of nature analogy and ends “in a particular form of political and social organisation based on principles derived from this natural state,” Jahn writes, “posit[s] the normative validity of the latter for all of humanity” (Jahn, 2000: xiv). Valdez’s (2019) analysis of Perpetual Peace, on the other hand, argues that Kant’s anticolonialism is Eurocentric because it is rooted in a concern for peace among European states rather than determining appropriate relationships between European and non-European peoples (pp. 23–55). The abstract, Eurocentric quality of the analogy between the state of nature and so-called “primitive” societies produces hierarchies that authorize attempts to order or domesticate supposedly disordered peoples and states. Studies of Kant’s attitude toward imperialism and colonialism are in this way also characterized by a division between statist and cosmopolitan readings of Kant’s theory of world order.

Sankar Muthu argues that it is the hypothetical and Eurocentric qualities of Kant’s analogy between individuals and states that makes it the ground of a genuinely anti-colonial theory of world politics that respects human diversity. Kant’s analogy between pre-civil individuals and states, he argues, “models not humanity per se, but a particular form of noncivil social relations that he believes existed historically” among European states and is thus not “a basis from which to urge new world peoples to enter into a settled civil condition but rather to demand that already established states enter into a voluntary congress to secure . . . international peace” (Muthu, 2003: 264). Moreover, Muthu argues that Kant’s state of nature analogy is “hypothetical” because it refers primarily to the international system. “The imperializing rhetoric that sometimes follows from a naturalistic representation of New World peoples in social contract theories,” Muthu (2003) claims, “does not hold in Kant’s political thought because of his exclusive use of the inter-national order as an empirical example of a natural state” (p. 253). On this basis, he argues that Kant’s vision of cosmopolitan order does not consist solely of public right states, but one in which “agriculturalist, pastoral, and nomadic peoples respect one another’s independence and collective freedoms” (Muthu, 2003: 264). Defenses as well as critiques of Kant’s anti-imperialism thus both draw on an account of Kant in which the international is analogous to a pre-civil condition. Kant’s political philosophy thus provides a common terrain for otherwise antagonistic theories of international politics.

The relationship between Valdez and Muthu’s positions on Kant’s theory of International Relations is instructive for demonstrating the dilemma this paper aims to address. Though they draw opposing conclusions from the same view of Kant’s domestic analogy, they ultimately share a vision of global cosmopolitan justice that they see Kant as articulating beyond the system of states. For Muthu, this is found in Kant’s anti-colonial cosmopolitanism, whereas for Valdez it is the ideal of global justice. Although I share Valdez’s aim to “put in question a system of sovereign states and interstate coordination that has historically organized world governance” (Valdez, 2019: 177), the analysis here points to some of the difficulties of discarding Kant’s cosmopolitan framework and suggests that doing so requires critical investigation of the concept of the globe that structures much of Kant’s critical and political thought.

The analogy between individuals in a “state of nature” provides a foil and a ground for arguments about whether an international system represents a realist or liberal, imperialist or anti-imperialist, statist or cosmopolitan world political order. The result is that these analyses mobilize a particular understanding of Kant’s domestic analogy to promote a normative ideal that preserves a Kantian vision of world unity. The aim of what follows is to identify and elaborate the limits of the ideal of order and unity that lies underneath these oppositions. To do so, it is worth examining Kant’s account of the relationship between international and cosmopolitan right.

International and cosmopolitan right

The status of the domestic analogy in Kant’s writings has consequences for the relationship between international and cosmopolitan right. If Kant is a proponent of an analogy between individuals in a pre-civil condition and states in an international system, then international and cosmopolitan right are distinct and separate realms. There is ample textual evidence for this view. Among states, Kant (1991 [1784]) writes in An Idea for a Universal History with a Cosmopolitan Purpose, there exist “precisely the same evils which formerly oppressed individual men and forced them into a law-governed state,” and these evils “must force the states to make exactly the same decision . . . as that which man was forced to make . . . in his savage state” (p. 47). Furthermore, in the Metaphysics of Morals, Kant (1991 [1797]) argues that international right requires the establishment of “a federation of peoples in accordance with the idea of an original social contract” to overcome the “condition of war (the right of the stronger)” that exists between states (pp. 164–165). In Perpetual Peace, moreover, Kant (1991 [1795]) claims that “people who have grouped themselves into nation states may be judged in the same way as individual men living in a state of nature, independent of external laws” (p. 102). On this account, the problem of international politics is identical to that of domestic politics and requires individual states to unite into a civic whole of which cosmopolitan right provides the model.

Kleingeld advances the most influential argument to this effect by claiming that international right concerns relations between states while cosmopolitan right concerns relations between states and “foreign individuals who are not state officials” (Kleingeld, 2011: 72). With some exceptions (Flikschuh, 2010; Holland 2017), this view of the distinctiveness of cosmopolitan right is the norm in philosophical commentaries on Kant. Kant certainly does identify cosmopolitan right with the general problem of the relations between individuals and foreign states and a minimum right to hospitality. Yet several factors complicate this picture. First is the way that Kant includes relations between individuals and foreign states under the category of international right in the Doctrine of Right, as we will see below. Moreover, Kant seems to think that these relations arise as international order becomes globalized and are thus not incompatible with the idea of a global system of states. International and cosmopolitan are not two static categories of public right, but, as the following analysis outlines, exist in a historical relationship. Finally, as Kleingeld describes, it is the spherical shape of the globe that inspires Kant’s account of the hospitality rights of individuals. The kind of order that I argue below is the subject of an analogy between system and sphere thus remains present in the case of cosmopolitan order conceived in terms of individual-state relations.

Moreover, as Chiara Bottici (2003) points out, there are good reasons to doubt the claim that Kant’s understanding of the international relies on the domestic analogy conventionally understood (p. 45). At times Kant suggests that the problem of the international must be understood in different terms than in relation to individuals prior to civil society. The uniqueness of the problem of the international is evident in Perpetual Peace, where Kant (1991 [1795]) argues that

while natural right allows us to say of men living in a lawless condition that they ought to abandon it, the right of nations does not allow us to say the same thing of states. For as states, they already have a lawful internal constitution, and have thus outgrown the coercive right of others. (p. 104)

In Metaphysics of Morals, Kant (1991 [1797]) writes that

a state of nature among individuals or families (in their relations with one another) is different from a state of nature among entire nations, because international right involves not only the relationship between one state and another within a larger whole, but also the relationship between individual persons in one state and individuals in the other or between such individuals and the other state as a whole. (p. 165)

Here, the problem of international right has to do not with isolated individuals cut off from any collective community, but relations between states and between individuals and states in the context of a larger political whole.

Furthermore, while Kant (1991 [1797]) argues that an international federation must be established on the basis of a social contract, he adds that “this association must not embody a sovereign power as in a civil constitution, but only a partnership or confederation” (p. 165). Kant (1991 [1795]) explicitly excludes the possibility of a world state in favor of what he calls the “negative substitute” of a federation of states (p. 105). ³ And finally, Kant (1991 [1795]) refers to the relationship between international and cosmopolitan right as analogical, writing in the appendix to Perpetual Peace that the maxims of cosmopolitan right in terms of the relationship between politics and morality “are easy to formulate and assess on account of its analogy with international right” (p. 128). On this view, international order cannot be achieved in an analogous manner to order within states, and thus Kant cannot be said to be a simple advocate of the domestic analogy.

Given the textual evidence for both positions and the apparent tension between them, the question becomes, as Bottici (2009) remarks, “how this can possibly be so” (p. 61). Most commentators answer by following Gallie (1978) in reading Kant as “par excellence, the philosopher of sharp antitheses and unbridgeable dichotomies” (p. 12) and point to the dualisms that populate Kant’s writings as an explanation for the ambivalences that characterize his political thought (Bartelson, 1995; Hutchings, 1995; Walker, 1993). Bottici (2009), for example, suggests that Kant’s ambivalence is a result of the difference between the certainty of abstract philosophical justification and the “contingency and multifaceted variety” (p. 61) of empirical phenomena. On this view, it is the gap between is and ought that explains Kant’s ambivalence regarding the ultimate political ends of “man.” This diagnosis, as seen above, is shared by a range of literature on Kant’s world politics in which the domestic analogy is a problem tied to sovereignty, difference, anarchy, and disunity. Kant’s conception of analogy, however, as we will see in the next section is linked to form, unity, and relation. It is on the basis of a particular form of unity that Kant analogizes between international and cosmopolitan right. To see how this is so, a closer look at Kant’s own understanding of analogy is required.

A proportion of concepts: Kant’s analogy

Most commentators take Kant to be posing the problem of international politics in terms of an analogy between states and individuals, but these analyses rarely consider Kant’s own conception of analogy or the explicitly analogical relationship between international and cosmopolitan right.

By taking Kant’s conception of analogy into account, however, a different picture emerges of the relationship between the two forms of right. Kant does not provide many clues to the meaning of the explicit analogy between international and cosmopolitan right found in Perpetual Peace. Studies of the domestic analogy consider analogy to mean either simply similarity or likeness, which reinforces the common view that analogy is a “weak” form of reasoning or use the term “homology” to indicate equivalence at the level of structure. ⁴ It will thus be helpful to be more specific then about what is meant by analogy in the sense that Kant understood it.

Although Kant’s comments on analogy display ambivalence about its value as a form of reasoning, ⁵ a relatively coherent account of the concept can be found across Kant’s writings (Callanan, 2008), one that in large part reflects similar uses of the term in the natural philosophy of the 18th century and a tradition of philosophical speculation on living beings whose origins are identified in the work of Aristotle (Lloyd, 1966; Van Den Berg, 2018). It is against a certain common usage of the concept, however, that Kant defines analogy in its specificity. “Cognition according to analogy,” he writes, “surely does not signify, as the word is usually taken, an imperfect similarity between two things, but rather a perfect similarity between two relations in wholly dissimilar things” (Kant, 2002 [1783] 146–147). This passage expresses a central feature of Kant’s conception of analogy: identity of relation. Analogy does not involve a comparison between two things in terms of their similarities and differences but enables new knowledge by presuming that relations between elements are identical in things that are otherwise wholly unlike one another.

Also unique to Kant’s conception of analogy is the distinction between mathematical and philosophical analogies, which mirrors key distinctions in Kant’s work between quantity and quality and between constitutive and regulative principles. Mathematical analogy, otherwise known as proportion, refers to “formulas that assert the identity of two relations of magnitude” (Kant, 1998 [1781] 297–298 [A179/B222]). These formulas are such that “if two members of the proportion are given the third is also thereby given, i.e. can be constructed” (Kant, 1998 [1781] 298 [A179/B222]). Mathematical analogies are what Kant calls constitutive, because they enable the construction of concepts a priori, without reference to empirical intuition (Callanan, 2008). For example, if one knows that 1:2 :: 4:x, it can be inferred that x equals 8. Kant refers to this kind of analogy in the lectures on metaphysics when he explains that “analogy is a proportion of concepts, where from the relation between the two members that I know I bring out the relation between a third member, that I know, to a fourth member, that I do not know” (Kant, 1997: 99 [28: 292]). Analogy, in this sense, concerns the identity between relations present in two objects, such that a fourth term can be inferred from an identical form of relation. In mathematical analogies, two quantitative relations are compared, which means the analogical inference can be made with certainty.

Proportion works differently in relation to concepts, however, because concepts lack the precision and certainty of mathematical formulae. Philosophical analogies, Kant explains, concern

the identity of two . . . qualitative relations, where from three given members I can cognize and give a priori only the relation to a fourth member, but not this fourth member itself, although I have a rule for seeking it in experience and discovering it there. (Kant, 1997: 99 [28: 292])

Philosophical analogies are regulative because they cannot provide the certainty and exactitude of mathematics; while they can be used to infer the existence of a fourth term and its relation to a third term, the fourth term cannot be determined in its specificity. Only the relation between this fourth member and the third can be inferred, as in the formula a:b :: c:d. Kant gives an example of this kind of analogy, writing that

By means of such an analogy I can therefore provide a concept of a relation to things that are absolutely unknown to me. E.g., the promotion of the happiness of the children=a is to the love of parents=b as the welfare of humankind=c is to the unknown in God=x, which we call love: not as if that unknown had the least similarity with any human inclination, but because we can posit the relation between God’s love, and the world to be similar to that which things in the world have to one another. (Kant, 2002 [1783]: 147 [4:358])

Philosophical analogies thus work to bridge the gap between the known and the unknown by the inference suggested by an identity of relation. Analogy makes no claim on any specific similarity between its members, but that of an identical relation between elements; it is the proportion between the elements and not the elements themselves that are the subject of the analogy.

That Kant views international and cosmopolitan right to be related analogically thus suggests that both share a particular relation between parts and whole. While their specific contents and character may differ, the relation between the elements involved in international and cosmopolitan politics, on this view, remain identical. That relation, I argue below, is a reciprocal (irreducible) relation between parts and whole. It is this kind of relationship that describes the relation between the order displayed by the systematic unity that characterizes international order and the order displayed by the geometrical sphere—the globe.

Earth as globe

Kant’s political writings rely on a conception of the earth as a geometrical sphere, and it is to this figure which Kant refers with the concept of world in the political writings (Gaston, 2006: 18–28). The advantage of the figure of the sphere, according to Kant, is that it permits the identification not only of the limits of human reason in relation to the world, but also its boundaries. That is, the sphere enables consideration not just of limits to knowledge of the world from a given subjective position, but the limits of any human knowledge of the world in general. Thinking reason as a whole opens up the possibility of determining not just the limits of the reason of individuals in particular places and times, but the conditions of possibility of human experience of the world in general. Hence, Kant (1997 [1781]) imagines that

our reason is not like an indeterminably extended plane, the limits of which one can cognize only in general, but must rather be compared with a sphere, the radius of which can be found out from the curvature on the area of its surface . . . from which its content and its boundary can also be ascertained with certainty. (pp. 654–655 [A762/B790])

To determine the limits of reason is to identify the limits of one’s finite experience in relation to the external field composed of an infinite number of objects, while to determine its boundaries is to identify the immanent limits of reason, the limits reason cannot overstep in any time or space.

Thinking the earth as a sphere yields knowledge that would otherwise be out of reach by enabling a reciprocal relation between parts and whole such that one can obtain knowledge of the whole from a determinate part, and vice versa.

If I represent the surface of the earth (in accordance with sensible appearance) as a plane, I cannot know how far it extends. But experience teaches me this: that wherever I go, I always see a space around me in which I could proceed further; thus I cognize the limits of my actual knowledge of the earth at any time, but not the boundaries of all possible description of the earth. But if I have gotten us as far as knowing that the earth is a sphere and its surface the surface of a sphere, then from a small part of the latter, e.g. from the magnitude of one degree, I can cognize its diameter and, by means of this, the complete boundary, i.e. the surface of the earth . . . and although I am ignorant in regard to the objects that this surface might contain, I am not ignorant in regard to the magnitude and limits of the domain that contains them. (Kant, 1997 [1783]: 653 [A759/B787])

Imagining that the earth is a geometrical sphere enables thought to move from partial knowledge to knowledge of the whole. For Kant, the sphere is a model for enabling knowledge of the world from inside that very world, without having to step beyond the bounds of reason. In short, a sphere enables knowledge of the whole from a determinate part within that whole, that is, knowledge that does not require an unconditioned view from “outside” as its guarantee. The figure of the geometrical sphere holds out the possibility of a total knowledge that does not rely on a dogmatic “view from nowhere.” The sphere is a machine for the production of immanent knowledge—knowledge of the world that comes from within it.

One of the primary conditions imposed by the spherical globe on human political life, in Kant’s view, is its finitude. “Since the earth is a globe,” Kant (1991 [1795]) writes in Perpetual Peace, “[men] cannot disperse over an infinite area, but must necessarily tolerate one another’s company” (p. 106). Contrary to the understanding of the earth as an infinite plane, in which people could disperse indefinitely, the globe produces a set of limits on human activity in general, and not only within the conditions given by a particular juncture in space and time. In Metaphysics of Morals, Kant (1991 [1797]) explains that

through the spherical shape of the planet [Men] inhabit (globus terraqueous), nature has confined them all within an area of definite limits. Accordingly, the only conceivable way in which anyone can possess habitable land on earth is by possessing a part within a determinate whole in which everyone has an original right to share. (p.172)

Finally, Kant (1991) writes that “all nations are originally members of a community of the land . . . a community of reciprocal action (commercium), which is physically possible, and each member of it accordingly has constant interaction with the others” (p. 172). In all these cases, the form of finite unity represented by the figure of the globe—the earth conceived as a geometrical sphere—enables a reciprocal relation between parts and whole, a relation whose philosophical analogue is the systematic unity of international order.

An analogous kind of relationship between parts and whole is found in systematic unity, the purposiveness with which Kant argues biological life and by extension what Kant considers the ultimate end of nature, the human species, must be understood. Kant’s most explicit consideration of the regulative idea of systematic unity is found in the Critique of the Power of Judgment. This regulative idea of unity is required to make judgments about what Kant calls “organized beings,” or biological organisms. In this work, Kant is concerned with the relation between theoretical and practical reason, that is, the form of reason that deals with the realm of freedom, and the form that deals with the realm of nature. In Kant’s view, knowledge requires the application of concepts from one realm to the other, yet the means by which thought could mediate between them had yet to be elaborated. The answer, according to Kant, is reflective judgment, which moves from the particular instance to a general rule.

The universal principle that must be presumed to make reflective judgments is purposiveness. That is, for things in nature which cannot immediately be understood as instantiations of universal laws, one must assume an end that gives unity and purpose to the object in question, so that it can be understood in relation to a unified whole. The kind of objects that require this kind of judgment, according to Kant, are what he calls “organized beings,” what today are called biological organisms. Reasoning about life, in Kant’s view, requires reflective judgment, since the complexity of living beings cannot be explained completely by any a priori law, that is, cannot be explained mechanically in the manner of the natural sciences of the day. For “it is quite certain,” Kant thinks, “that we can never come to know the organized beings and their internal possibility in accordance with merely mechanical principles of nature, let alone explain them” (Kant, 2000: 270–271 [5:400]). Thus, while Kant encourages the use of the methods of natural science based on a mechanical conception of nature as far as they prove useful, such methods can never hope to provide a complete account of living beings and therefore must be supplemented by teleological judgment that conceives of organisms as purposive.

Rather than a claim to knowledge, purposiveness is the principle that must be thought to achieve knowledge, to ground the systematic unity of science. Kant links philosophical analogy to reflective judgment, that is, judgments made when knowledge of the universal is impossible (Kant, 2004: 626). ⁶ This requires making a judgment as if there were a universal principle providing the kind of unity that enables scientific knowledge. The kind of unity given by such regulative principles is called by Kant systematic or purposive and consists of an irreducibly reciprocal relation between parts and whole. This is far from an organic view in which the parts are determined by a whole that exists over and above them. Rather, the relation between parts and whole in the case of organized beings, according to Kant, is one of mutual cause and effect, in which parts and whole are simultaneously the means and ends of one another, a relation that Kant calls reciprocal.

Organized beings are, in this sense, “self-organizing” (Kant, 2000 [1790] 245 [5: 373]), in that they cannot be explained completely with reference to external causes; rather, they carry within them the principle of their immanent self-constitution. In this sense, what Kant calls a reciprocal relation between parts and whole is as an irreducible relation, in that no account of the parts, no matter how complete, can provide an account of the whole, and no account of the whole can be complete absent an accounting of the parts. Rather, Kant (2000 [1790]) explains,

in such a product of nature each part is conceived as if it exists only through all the others, thus as if existing for the sake of the others and on account of the whole, i.e., as an instrument (organ) . . . that produces the other parts (consequently each produces the others reciprocally). (p. 245 [5: 373])

Purposiveness, for Kant, thus consists of a relation between parts and whole in which neither exists independently of the other such that an organized being is considered both end and means, both cause and effect of itself. Organized beings are not simple aggregates of their parts, as in mechanical structures, but express a relation that cannot be reduced to their parts or the relations between them.

Crucially, as in the case of philosophical analogy and the systematic unity of reason, the purposiveness of biological organisms is a regulative rather than a constitutive principle. The difficulty with a regulative concept of unity, however, is that it is unity that regulative principles are responsible for supplying. If absolute totality is beyond the bounds of reason, the question arises as to the kind of finite unity given by regulative principles, in which parts are combined in a reciprocal relation with a whole. The regulative consists not simply of the teleological principle, but the form of unity expressed by such a principle. In this case, that form is the systematic unity that finds its highest expression in the sphere. It is this kind of unity, I argue, that characterizes international order in Kant’s political writings. Unlike the mechanism of nature, organized beings can only be cognized in relation to their end, that is, the unity toward which their development tends. The ultimate end of nature, according to Kant, is the human species, which achieves this end only by developing a global and thus cosmopolitan system of states.

Cosmopolitanism as political globalization

The analogy between the reciprocal relations among parts and whole that characterize a system and the mathematical relation among parts and whole enabled by the geometrical sphere suggests a different reading of the problem of the domestic analogy in Kant’s political writings than that currently dominant in international relations, political theory, and philosophy. By identifying the significance of this kind of unity for Kant’s framing of the problem of international right, I argue that Kant understands international order not by analogy with individuals but by analogy with the world imagined as a sphere. Considering the political writings in the context of the idea of systematic unity present in the first and third Critiques suggests that Kant’s ambivalence with respect to the domestic analogy is consistent with a single account of the problem of international order that stems from a diagnosis of the political situation at the time of Kant’s writing. In this sense, international and cosmopolitan right are distinguished on the basis of a historical and geopolitical criterion: the globalization of the international system. This suggests that the telos of Kant’s philosophy of history, for him the highest possibility for political order on earth, is a global system of states.

Many commentators now highlight the close relationship between Kant’s critical and political projects. Scholars have identified several structural isomorphisms between Kant’s conception of reason and his thinking on politics that demonstrate how the relation between the critical and political writings reflect Kant’s struggle with problems that cross the boundary between philosophy and politics (Hutchings, 1995; Williams, 1992). On these readings, “international relations is not a set of problems that [Kant] merely addresses,” but is, rather, “continuous with his project of critique” (Franke, 2001: 68). The reading that follows approaches the relation between the critical and political writings similarly, as related elements in a broader philosophical-political project. This is not to insist on any kind of completeness or consistency in Kant’s corpus but rather to show how the appeal to a particular kind of unity works to figure difference in relation to both universal reason and international order. This conception of unity appears in the third Critique in relation to the teleological judgment of natural organisms, but also, as we will see below, in the political writings. ⁷

The significance of this purposive or systematic idea of the order of nature for the political writings is such that Molloy suggests Perpetual Peace can be understood as a kind of “sequel” to the third Critique (Molloy, 2017: 51). As Henry Allison explains, “far from being a mere popular or occasional piece, Perpetual Peace stands in essential connection with the third Critique and its systematic concern with an Übergang between nature and freedom” (Allison, 2012: 226). The unification of nature and freedom is for Kant not just an intellectual exercise but rather the subject of a historical process the success of which depends on the development of specific forms of political order, namely the state and international system. Kant’s philosophy, including political philosophy, must therefore be interpreted in relation to Kant’s own observations of the historical moment and their meaning for the possibility of a broader historical trajectory. I thus situate Kant’s writing on the problem of international politics in relation to his own diagnosis of contemporaneous political developments regarding international order.

The continuity between Kant’s philosophical and political projects becomes evident when political tracts such as Idea for a Universal History with a Cosmopolitan Purpose and Perpetual Peace are read in light of the regulative idea of the purposiveness of nature developed in the third Critique. In Idea for a Universal History, Kant describes the relationship between the problem of relations between individuals within states and the problem of relations between states themselves. The former, Kant (1991 [1784]) argues, is “the most difficult and last to be solved by the human race” yet “subordinate” to the latter problem because “it cannot be solved unless the latter is also solved” (p. 47). For Kant then, international politics is a problem prior to domestic politics; the problem of political life at the level of the whole must be settled before political life within states can be determined. Kant (2000 [1790]) links teleological judgment and political order in the appendix to the third Critique where he positions Man as the “ultimate end of nature here on earth, in relation to which all other natural things constitute a system of ends” (pp. 295–296 [5:428]). Fulfilling its role as the ultimate end of nature, for Kant, requires the full development of man’s capacities, which is possible only within the proper form of political order. “The formal condition under which nature can attain this final aim,” according to Kant (2000 [1790]) is a universal civil society, for which “even if humans were clever enough to discover it and wise enough to subject themselves willingly to its coercion, a cosmopolitan whole, i.e., a system of all states that are at risk of detrimentally affecting each other, is required” (p. 290 [5: 422]). The kind of cosmopolitan political order Kant imagines here expresses the organic unity characteristic of organized beings in which parts (in this case states) are unified in relation to a systematic whole.

Although rarely employed explicitly in the political writings, the significance of systematic unity is clearly present in Kant’s account of international and cosmopolitan right. ⁸ It is the beginnings of an international order in Europe that allows Kant to imagine

a great political body of the future . . . Although this political body exists for the present only in the roughest of outlines, it nonetheless seems as if a feeling is beginning to stir in all its members, each of which has an interest in maintaining the whole. (Kant, 1991 [1784] 51)

This international order emerging in Europe embodies a political form which can act as a universal political order that encompasses the entirety of humanity. Kant imagines that “after many revolutions,” the system of states emerging in Europe may achieve “the highest purpose of nature,” a universal cosmopolitan order that acts as “the matrix within which all the original capacities of the human race may develop” (Kant 1991 [1787] 51). This process has already begun, as Kant (1991 [1796]) explains later in Perpetual Peace, since “the peoples of the earth have entered in varying degrees into a universal community, and it has developed to a point where a violation of rights in one part of the world is felt everywhere” (p. 107). The problem of international right, unlike the state of nature between individuals, is thus not a matter of establishing unity among states, a process which Kant’s claims has already begun in his own time, but of thinking about relations between states in the context of that unity.

While contemporary discourses of International Relations and philosophical commentaries on international and cosmopolitan right treat terms “system of states” and “cosmopolitan whole” as opposites such that “system” expresses sovereignty and difference and cosmopolitan whole a unity, here, the kind of cosmopolitan order Kant envisions expresses a unity given by its systematic character. In this sense, for Kant, the move from independent states that relate to one another in relation to a common political community, however minimal, which is the subject of the classic domestic analogy, has already occurred. In the section of Metaphysics of Morals that deals with international right, Kant (1991 [1797]) cites “the assembly of States General at the Hague in the first half of this century” (p. 171) as an example of the presence of the kind of international political community capable of approximating a cosmopolitan whole. ⁹ The international, then, even in its most rudimentary form, for Kant is a remedy to the problem of an uncivil condition between states. The “state of nature” between states is already considered overcome by the “civil” condition introduced by the systematic quality of international order. Kant’s account of international right concerns relations between states in the context of a nascent international order whose existence the analogy between individuals and states is meant to explain.

However, based on Kant’s understanding of analogy, to say that an international and world politics are analogous in terms of the kind of order that they display is not to say that they are identical. So, what is the difference between them? Kant envisions this difference between international and cosmopolitan right not in terms of the form of political order, but in terms of its spatial extent. Man’s exit from the state of nature is thus not yet achieved with the establishment of an international system not because the international is a sign of the absence of political order, but because the boundaries of that community have not yet spread to encompass the globe. The nascent international order, on this account, becomes cosmopolitan by growing until it encompasses the entirety of the globe. The development of man’s capacities requires that the international political order established among European states “will gradually spread further and further by a series of alliances” such that “the whole will gradually spread further to encompass all states” (Kant, 1991 [1795] 104). Kant’s (1991 [1795]) international state “would necessarily continue to grow until it embraced all the peoples of the earth” (p. 105). The culmination of universal history, the cosmopolitan whole that constitutes a universal kingdom of ends, is not a change in the form of political order, but an extension of the systematic unity of the international over the entirety of the globe. An exit from the state of nature among states is thus not fully achieved with the establishment of an international order because the boundaries of that order have not yet become global.

Kant’s domestic analogy

Reconsidering the problem of the domestic analogy in Kant’s works points to some broader conclusions related to international political order and global geopolitics. First, it helps explain why Kant’s conception of international order lends itself to such contradictory readings and works as a ground for such a wide range of debates. Kant’s two analogies are related as part of a single philosophy of history that culminates with the globalization of the nascent European system of states. Second, it suggests a new formulation of the problem of the domestic analogy in international politics. Rather than either the synonym or antonym of world politics, the relation between international and global order is conceived by Kant as analogical—the international system displays the kind of unity characteristic of the world as a whole. Rather than an unwarranted application of domestic principles to the international sphere, Kant’s domestic analogy lies in the way he conceives of the international as ordered—that is, unified—in a manner analogous to that of the world—the spherical globe. The analogical relation between international and global order enables a domestication of possibilities for political order on a world scale through an international order conceived as systematically unified.

The domestic analogy, on this account, is related to the way existing claims to world political order are enabled through specific accounts of form, order, and unity that organize relationships between human beings, the earth, and the boundaries of world order. To the extent that Kant considers international order in systemic terms, this model operates, however implicitly, on a normative conception of order that takes as its model the mathematical precision of geometry. The geometrical sphere, in Kant’s account, works as the model of ordered perfection which systematic wholes—whether organized beings, transcendental reason, or the international system—emulate. The boundaries of a systematic order are thus determined by Kant in relation to error or deviation determined by an ideal of perfection expressed by mathematical proportion (i.e. ratio). For Kant then, the boundaries of world order are determined by a relationship between man and the earth mediated by geometry.

Critiques of the structuring effects of the figure of the globe in modern political thought are often made on the basis of a gap between the concept of the globe and the earth as it really is. It is the abstraction of geometry from the actual conditions of the world and the false universalism that follows from such abstraction that, for these thinkers, make the globe a problem. For Franke, for example, the problem with the ideal of thinking reason and the earth as geometrical spheres is that such a figure expresses the stasis and uniformity of Newton’s account of absolute space and thus cannot account for contingency and change (Franke, 2001: 111–154). Bruno Latour similarly argues that the spherical globe is a conception of the earth that exhibits “the view from nowhere,” at the expense of the particular ecological conditions that sustain planetary life (Latour, 2018: 68). As we have seen, however, for Kant the figure of the spherical globe is a response to the consequences of the position that a view from nowhere has never been and will never be available to the creature called “man.” Systematic unity attempts to resolve the gap between real and ideal through a universal, teleological history of which a global international order is the culmination.

This is the terrain on which many of the most contested debates in International Relations —between realist and liberal, imperialist and anti-imperialist, international and global visions of world order—play out and that ought to be the object of critical investigation. As the analysis here shows, this terrain is a particular concept of order found in systematic unity and the geometrical sphere. This analysis thus points to the significance of the problem of geopolitics both in Kant’s political writings and in contemporary international relations. Kant’s account of the political consequences of a specific understanding of earthly order structure and domesticate a wide range of contemporary theories of world politics. Given the way the boundaries of world order are increasingly being put into question both by the persistence of global inequality and the effects of political and economic globalization on the biosphere, their reproduction in theories of international politics is a key contemporary problem. Addressing this problem requires greater understanding of the way such boundaries claim to determine the conditions of possibility for any world political order for human beings on earth.

These boundaries are evident in perhaps the most notable dimension of Kant’s analysis of international politics, which is the way that, whether international order is understood in statist or cosmopolitan, imperialist, or anti-imperialist terms, contemporary theories of international order begin at Kant’s highest ambition for humanity—the spatial extension of international order over the entire globe. While Kant’s analysis looks forward to the global spread of European interstate order, current analysis looks backward at what is understood as a completed process—the globalization of international society. The end of “man,” only a future possibility for Kant, is the starting point of international relations today: a global international political system. To the extent that international order is theorized in systemic terms—whether of the realist or liberal, systemic or societal, scientific or traditional varieties—scholars of international relations accept Kant’s answer to the problem of perpetual peace. It is this answer—systematic unity—that in part enables claims to political globalization and whose boundaries confront attempts to articulate alternative conceptions of political order on a planetary scale—in other words, to think and practice a world politics.