Lost in Space: From Res Communis to Terra Nullius

Abstract

This article examines the ties between early modern natural law theories regarding property and sovereignty and contemporary debates regarding the status of outer space. It shows that the division within early modern natural law regarding the question as to whether property is created prior to or as a consequence of sovereignty is now reflected in uncertainty about the reach of the 1967 Outer Space Treaty, which ostensibly forbids only sovereign claims. The article locates early modern natural law arguments in the context of the imperial ambitions of European states and the Machiavellian drive for greatness, which was understood to be the means whereby to maintain a state. Natural law flourished where new space opened for these expansionist ambitions, a space where positive law had no jurisdiction. It is the renewed opening of space in which to expand the resources of states in the contemporary drive to colonize the Moon and Mars, which underpins the revival of natural law perspectives. These parallels, in both the expansionism and the natural law ideas, are made explicit by contemporary writers who draw upon the early modern understandings of both grandezza and natural law concepts such as res communis, res nullius, and terra nullius. Their arguments, however, are derivative of the early modern authors and similarly divided, whereby the most liberal position, arguing that property precedes sovereignty, is also most closely tied to imperial ambition.

There is a vast literature on the politics of outer space and also a vast literature on the law of space, including several specialist journals on the subject. Space has not featured prominently, however, in the history of political thought perhaps in part because it is associated with the future rather than the past. In this paper, I will argue that the history of political thought and the history of empire are essential to understanding the contemporary law and politics of space. The need for a better understanding of sovereignty and property in space is now urgent. Over the next several years, the Artemis missions will return astronauts to the surface of the Moon, planned for 2027; they will establish a space station orbiting the Moon, planned for 2028; and they will then establish habitation with “the first long-term presence on the Moon” at the lunar South Pole, close to ice deposits, planned for 2030 (NASA 2024). International rivalry is a driving force. China and Russia also have plans for habitation on the Moon with a series of missions similarly culminating in an international Moon base, also at the lunar South Pole, planned for 2035. Further momentum is driven by the level of corporate involvement in these missions, notably from Space X and Blue Origin. Finally, the scramble is driven by resources, including the possibilities of solar farming in geostationary orbit and the presence of valuable materials on the Moon, on Mars, and on near-Earth asteroids, such as helium-3 and lithium, both of which could be important for the development of sustainable energy on Earth.

There are three ways in which the history of political thought shapes the understanding of space in the twenty-first century. Firstly, the idea that the expansion of the state is necessary for its survival, which was central to rationalizations of empire over the past five hundred years, has now been projected into space. The second feature is the role of corporations in that expansion and the manner in which those corporations became vehicles for political ideas. Following the demise of state-led attempts to explore space in the context of the Cold War, corporations are once again central players in expansion, and once again, whether empire is located in the state itself or in the corporation is uncertain.

Thirdly, the legal and political debates about the possibilities of property and sovereignty in outer space are drawing upon the previous five centuries of international law that was itself forged in relation to European empires. The key issue dividing those discussions of property and sovereignty revolves around the prohibition in the 1967 Outer Space Treaty against declaring sovereignty over any celestial body. Some contributors to the debates argue that it is possible to establish property in space even while sovereignty is forbidden. Others argue that, under the current treaty law, property in space is impossible to establish without sovereignty, frequently adding that a new regime needs to be established so that potential investors in space enterprises can be confident about their activities. This division closely mirrors debates over the possibility of establishing property and sovereignty in empires from the early modern period through the twentieth century. Indeed, it reflects the fact that this question was not resolved. In this paper, I will focus largely on the third point above concerning the uncertain status of property and sovereignty in the law regarding space, but, in doing so, I will consider questions that arise from the first two points: the necessity of expansion and the role of corporations in expansion because they bear directly on the main point.

One of the most important motivations for the creation of empires by modern states was the concept of greatness. Glory was a common topic for Renaissance humanists, but Machiavelli shaped this discourse into an argument concerning the importance of liberty in order to achieve greatness. And greatness, for Machiavelli, was necessary in order to maintain a state (Armitage 2000; Hornqvist 2008; Machiavelli 1970; Skinner 1991). For Machiavelli, and for Guicciardini, greatness would be achieved by conquest and arms. Moreover, as Machiavelli argued, the pursuit of greatness was necessary to maintain power because those princes and republics that sat still would discover that when a state does “not molest other states, it will be molested by them” (Machiavelli 1970, 336 [II.19]). These arguments were adopted by the early modern apologists for English and Dutch expansion. In 1577, the Elizabethan adventurer Humphrey Gilbert wrote a letter to his Queen entitled “How Hir Majestie May Annoy the King of Spayne” (Gilbert 1940, vol.1, 170). In it he argued in Machiavellian vein that “The safety of Principates, Monarchies, and Common Weales rest chiefly in making theire enemies weake, and poore, and themselves strong and rich.” Some authors, such as Walter Ralegh, Gilbert’s half-brother, were strikingly Machiavellian in their emphasis on military conquest as the means to greatness. In his Discovery of Guiana, Ralegh admired the “actions of the Charles the fifte, who had the Maydenhead of Peru . . . together with the Spanish king now living, what territories he hath purchased, what he hath added to the actes of his predecessors, how many kingdomes he hath indangered . . . and that no yere is lese unfortunate but that many vessels, treasures, and people are devoured.” These abilities, he scoffed, arose “not from the trade of sackes [wine] and Seville oranges, nor from ought else that either Spain, Portugal, or any of his other provinces produce: it is his Indian Golde that indangereth and disturbeth all the nations of Europe” (Ralegh 1997, 127).

In the course of the sixteenth and seventeenth centuries, a series of authors beginning with Giovanni Botero, while Machiavellian in their commitment to the idea that the way in which to maintain a state was through expansion, argued that greatness would more reliably be achieved by “arts” and “industry,” as well as commerce, than by war (Botero 1606). Botero’s English translator, Robert Johnson, who was treasurer of the Virginia Company as well as a director of the newly formed English East India Company, wrote in 1609 that he admired the way in which the Spanish had used their overseas empire to dominate rival states within Europe, but this objective was achieved, he argued, through commerce rather than war (Fitzmaurice 2007; Johnson 1609, B3r). His commercial version of grandezza set the tone for the seventeenth century and underpinned the political economy of tracts such as Thomas Mun’s (1621) Discourse on Trade and Josiah Child’s pamphlets, both of them East India Company directors. In 1697, Josiah Child argued that “East India trade” had been “the great Engine that has wrought us into that Fund of Wealth which serv’d not only to Inrich us in Peace but has enabled us to defend ourselves thus long” (Child 1697, 3–5).

It is no accident that so many of the apologists for greatness in early modern England were also working for the East India Company, the Virginia Company, and other such chartered companies. Ventures for English expansion in the sixteenth century had been led by the state or private individuals and they were unsuccessful. When the East India Company was chartered in 1601, and the Virginia Company in 1606, English expansion had shifted to joint stock corporations as the means of raising the capital for expansion. Neither the state nor individuals could sustain the investment that joint stock companies were so successful in achieving and that proved necessary to creating colonies and maintaining global trade. Joint stock-chartered companies dominated English and, from 1707, British expansion through to the dissolution of the East India Company in 1857 and beyond, and they were used extensively throughout Europe for the same purpose (Sharman and Phillips 2020; Stern 2023).

Imperial states quickly discovered, however, that their instruments, the chartered companies, were in some ways too successful. The imperial corporations acquired extraordinary power and assumed many of the powers of states themselves, levying taxes, printing currencies, raising armies, and fighting wars, as well as conducting diplomacy and, perhaps most importantly, building civil societies from the ground up (or so they believed, often counting Indigenous populations for little or nothing) (Fitzmaurice 2003; Stern 2011). From the inception of these “company-states” a debate revived in Europe, a debate with medieval and ancient origins, about whether the corporations gave life to themselves, whether they were created by the natural sociability of their members, or whether they were created by the grace of the sovereign states that chartered them (a parallel debate, as we shall see, concerned whether property arises from the laws of the state or from the actions of individuals and could therefore arise outside sovereignty). This was an extremely important question because the autonomy of the corporations rested upon it, both in reality and perception. These companies were, at times, fiercely independent and could rival the states whose greatness they were supposed to serve.

One of the distinguishing features of the early modern humanist discourse upon greatness was that it became fused with natural law thinking in the seventeenth century (Tuck, 1999, Tuck, 1993). Hugo Grotius, working as a young man in the service of the Dutch East India Company, was the most important figure in this regard. He drew upon the Scholastic tradition and the work of Francisco de Vitoria to develop a theory of rights, notably rights in property and jurisdiction. Martti Koskenniemi has rightly emphasized the importance of the Salamanca School in providing the legal tools with which European empires would be imagined and justified for the following five hundred years: the rights of dominium, the right of war to defend dominium, and the universalization of those rights through the ius gentium (Koskenniemi, 2011, 2021). But while the Salamanca School imagined the terms upon which an empire might be legitimate (while frowning upon the conquests in the Americas), their thought lacked the motivation and ferocity that drove Europe’s expansionism from the sixteenth century onward. That drive was missing from the natural law tradition prior to Grotius but he introduced it by reinterpreting natural law from a humanist perspective (Tuck, 1999). Grotius also drew upon the Machiavellian tradition of grandezza to argue that a state’s first duty was to maintain itself and to do so through expansion. In defence of Dutch commerce in Asia during the Eighty Years’ War, he argued that if the Dutch “cease to harass the Spanish blockaders of the sea the shores of the whole world will soon be blocked off, and all commerce with Asia will collapse . . . that commerce by which the wealth of our state is chiefly if not entirely sustained” (Grotius 2006, 10). In contrast to previous humanist writers, however, Grotius represented this duty of self-preservation as not merely a necessity (and so, for Botero, a reason of state) but a matter of right. Grotius’s first law of nature, therefore, was that “It shall be permissible to defend [one’s own] life and to shun that which threatens to prove injurious” (Grotius 2006, 23). For Vitoria, a Thomist, the foundation of right had been natural sociability, and property was a matter of realizing resources for the end of sociability. Grotius argued, by contrast, that we have a right to do anything that promotes our survival and, as such, the creation of property, through use, was the first thing we need to that end. According to Grotius, therefore, the second law of nature was that we may acquire resources necessary for survival: “It shall be permissible to acquire for oneself, and to retain, those things which are useful for life” (Grotius 2006, 23). We have both a right and a duty to preserve ourselves, and the seizure of property—in other words, the seizure of the resources necessary to self-preservation—was also both a right and a duty. When the self who had to be preserved was understood as the fictional, or artificial, person of the state, this duty and right, as Grotius observed, included obtaining resources from outside the state upon which “the wealth of our state is chiefly if not entirely sustained.”

In formulating this understanding of self-preservation and property, Grotius posited the existence of a state of nature from whom the individual—a natural or artificial person—is separate and upon which they act. Property, therefore, arose from occupation or the seizure of things in nature and, as Grotius put it, to seize a thing “is not to see a thing with the eyes but to lay hold of it with the hands”—that is, occupation demanded the use of nature (Grotius 2004, 13). In making this argument, he crystallized a separation between human order and a natural and material order, with the further assumption that human agency acts upon the natural and material order, and he was, therefore, able to conceive of a presocial individual whose agency in the state of nature leads to the creation of a social contract that creates the state. This perspective can be contrasted with Aristotle’s declaration in his Politics that there is no individual prior to the state—a view that was largely still shared by a thinker as close to Grotius as Vitoria. The separation, however, between the natural and human orders was followed by all of the seventeenth- and eighteenth-century natural law and natural rights writers, including Hobbes, Locke, Pufendorf, Rousseau, and Kant.

These early modern natural law writers, however, disagreed on what the status of a thing was when it was seized in a state of nature. For Grotius, at least in his early work, property could be created through occupation in a state of nature. Locke declared that the reason for creating civil society was in order to protect the property that individuals, in nature, had created through use or through their labor. Hobbes and Pufendorf disagreed, arguing that while things may be seized in nature, they have no status as property until recognized as such by law, and there is no law where there is no state, so the property must be the creation of the state. All these writers posited a separation between the human and natural orders, but Locke argued for the most elaborate understanding for a presocial individual insofar as he argued that our labor makes the natural world a part of ourselves. Moreover, for Locke as for Grotius, property was necessary to self-preservation, and self-preservation (as for all the seventeenth-century natural law writers) was the first law and duty of nature. As a generation of scholars has now shown, a further aspect of Locke’s understanding of property was that it was bound up with his understanding of colonization (in which he was personally involved)—it was expansionist insofar as it was driven by the notion that nature abhors a void while underpinned by a very early modern assertion that filling such a void is not only a duty but also establishes right. For Locke, the more intensively we subject nature to our labor, or use, the stronger is our right.

Authors who argued that property rights were derived from the consent of a community, from the foundation of civil society, notably Hobbes and Pufendorf, were more likely to be skeptical about expansion and greatness. Hobbes said little about the acquisition of property for the purpose of self-preservation, and he rejected the notion that the seizure of increasingly greater resources, the policy of greatness, was necessary for the survival of the state. On the contrary, he argued, such “insatiable Appetite, or bulimia, of enlarging Dominion” was a cause of the dissolution of the commonwealth (Hobbes 1991, 222; Hont 2005, 17–22). Pufendorf agreed with Locke that different societies were placed at different points in the progress of historical time, although he did so with a sense of that progress being contingent upon cultural and geographical differences: “We pretend not that it was necessary all Things should be appropriated in the same Moment; but, according as the Temper or Condition of Men, the Nature of the Things themselves, and the Difference of Place required” (Pufendorf 1934, 376). In contrast to Locke, however, Pufendorf argued that the fact that some people had different forms of property did not prejudice their rights in that property. He did not insist that all societies would necessarily agree that private property was most useful, nor did either God or nature have any preference for the form of agreement various peoples reached on the nature of property: “Neither doth that Divine Grant, express’d in holy Scripture, describe any determinate Manner of Property, but only an indefinite Right of applying Things to such Uses as should be agreeable to the Wisdom, and to the Occasions of Men” (Pufendorf 1934, 373).

It would appear that those authors who were skeptical of the empire were so because of their conviction that property was derived from sovereignty. This conviction bound them to a recognition that each society determined on its own terms what form property should or should not take. At the same time, the idea that property was derived from sovereignty was maladapted to the needs of empire, or rather to the idea that the acquisition of resources external to the state was necessary to greatness and, therefore, to the preservation of the state. The seizure of things in a way that establishes a right, in a territory over which the seizer holds no prior authority, is not an act that can derive from consent precisely because the seizer has no political authority in that place and so no basis for consent and therefore no right. Rights, in such cases, can only come from an understanding that there is a direct relationship between the thing and the seizer. In such an account, rights do not need to be mediated by a state; they derive directly from the moral action of individuals in nature. For this reason, Locke’s theory, and also Grotius’s early work, in which right was based directly upon seizure and use, were most useful for the state pursuing expansion. ¹ For the same reason, writers such as Hobbes, Pufendorf, and Kant argued that such acts were usurpations rather than being the basis for rights. Unsurprisingly, therefore, the writer from this period who has been most closely associated with liberalism, namely John Locke (although he would not recognize the label), and who believed that there must be a basis for rights that does not derive from the state (because the state is created in order to protect such rights), has also been most closely associated with empire. ² The most liberal account of property rights was one that was adapted to the justification of empire. ³

Of course, Locke and Grotius’s understanding of property could be applied to the state itself when understood as a moral person rather than a natural person, and indeed, this was Grotius’s main purpose. As such, states, too, could exercise dominium over a place by seizing it. States, however, exist in an uneasy or dangerous relationship to each other without any prospect of that relationship being defused by the election of a sovereign over them. As Hobbes observed, “In all times, Kings and Persons of Soveraigne authority” have been in a posture of gladiators “their eyes fixed on one another” (Hobbes 1991, 90). A consequence of creating states was the creation of a new state of nature between states—it entailed shifting the problem of the state of nature from one sphere to another. In this new state of nature, the search for survival, through preeminence, was unceasing because it could not be resolved by an international sovereign (although Grotius argued that it was not a lawless condition). For the early modern natural law writers, therefore, the Machiavellian discourse of greatness intersected with a new understanding of political society as a state: an atomized moral person, modeled on the natural person, an aggressive rights-bearing individual who seeks self-preservation and the resources necessary to that end.

Max Weber argued that this world of aggressive rights-bearing individuals was the foundation of modern understandings of rights and liberty (Weber 1948, 71). When those individuals were the moral persons of states, in competition with each other in the society of nations, their rivalry led almost inevitably to the pursuit of empire. Weber and, some years ago, Richard Tuck, who cited Weber on this point, therefore concluded that the conditions of our freedom are interwoven with empire (Tuck 1999, 14–15). Looking closely at Weber, he argued that the expansion of Europe established the context for the liberal account of individuals as aggressive rights-bearing subjects fixated on establishing the conditions of their own survival. He declared: “The historical origin of modern freedom has had certain unique preconditions that will never repeat themselves. Let us enumerate the most important of these. First, the overseas expansions . . .” (Weber 1948, 71). In Weber’s account, expansion was the precondition for freedom rather than the particular notion of freedom being the driver for expansion. Reading Weber, and addressing the work of early modern natural law writers, Richard Tuck declared twenty years ago that “It is impossible to deny that the vividness of this picture of moral agents owed a great deal to the astonishing vividness of the picture of international action in the so-called age of European expansion” (Tuck 1999, 14–15). For Weber and Tuck, it is the moral and political thought that is indebted to the context of expansion. ⁴ However, the writers I have just cited—Gilbert, Ralegh, Grotius, Johnson, Mun, and Child—argue, on the contrary, that expansion was necessary for the survival of the state due to the aggressive competition between states, and their conception of the state was based upon the notion of the aggressive rights-bearing individual in a state of nature. Moreover, looking at the natural law writers, it appears to be those who argued for a direct relationship between individuals and property rather than one mediated by the state who were most fitted to imperial apologetics. To put that another way, it was a certain understanding of the individual and the state—or, of moral persons, because corporations were equally important—that gave rise to empires, not the creation of empires that gave rise to the understanding of that individual. That, at least, is how early modern authors understood the equation.

By the late eighteenth century, Europeans had come to know most of the globe, and they had lain claim to much of it. As a consequence, they had less need for a law that could conceptualize what was unknown and unclaimed. In the fifteenth century, natural law thinking was relatively limited in scope and had become, as Brian Tierney put it, “far removed from human life” (Tierney 2004, 10). Natural law was rejuvenated, however, by the European discovery of America. Here was a space in which the positive law of Europeans had no purchase. Even theologians such as Vitoria, who recognized that Native American peoples had their own legal systems, found that natural law was necessary to determine questions of global justice and to establish from above, as it were, who had jurisdiction over this new space. For Europeans, this need was no longer pressing by the end of the eighteenth century. They had either imposed their own laws on much of the space they discovered, agreed to mixed jurisdictions, or conceded the legal systems of the peoples they encountered. Natural law had less purpose for them in such an environment, and it was at this moment that the positive law perspectives of thinkers such as Bentham, who ridiculed natural law, and the utilitarians came to dominate nineteenth-century thought (Pitts 2005). With the globe partitioned in terms of sovereignty (or believed to be so), the idea that law came from sovereignty was fitting.

The humanist tradition was also challenged in the eighteenth century by the growth of commerce, particularly because wealth had been perceived by Renaissance humanists (like their classical sources) to be a source of corruption, a means whereby individuals were drawn away from the selfless pursuit of virtue in the performance of public office. Nevertheless, humanists such as Botero had thought about the role commerce could play in achieving greatness. With little of the unknown world left to conquer by the competing European powers, commerce provided an alternative route to greatness, and political economy replaced humanism as a source of counsel to states (Hont 2005).

Many Enlightenment thinkers were skeptical of empire, having witnessed the destruction wrought upon the metropolis by the Seven Years’ War, culminating in the American and French revolutions (Muthu 2003). They revived the ancient critique that empire produces luxury, corruption, and decline (Armitage 2000; Hont 2005). At the same time, European states sought a balance of power, notably in the 1713 Peace of Utrecht and the 1814 Congress of Vienna. The concern behind the balance of power was that which previously had lain behind the doctrine of grandezza: fear for the security and preservation of the state. That fear gave rise to new European expansionism in the nineteenth century, dubiously promoted as a “civilising mission.” A delicate balance was preserved in Europe even while the great powers sought an advantage abroad. Indeed, maintaining the balance of power in Europe necessitated expansion abroad if a state was to augment its strength. Late eighteenth-century and nineteenth-century political economists, such as Adam Smith and David Ricardo, argued that international trade and relations need not be perceived as a zero-sum game if each state focused on its comparative advantage. Liberal economists and political theorists argued for this mutually beneficial society of nations even while a parallel perception of zero-sum relations persisted, along with arguments, frequently pursued by liberals themselves, for expansion as the means to the preservation of the state.

Reflecting on nineteenth-century empires, John Hobson, writing in 1902, and Vladimir Lenin in 1917, argued that capitalism was the driver of empire. Capitalism, however, was the instrument of an older force, the preservation of the power of the state. The sense that empire was necessary to maintain a state remained important for many intellectuals, and it is often discernible behind a veneer of rhetoric on the civilizing mission. Alexis de Tocqueville argued in his Essay on Algeria that France must reestablish its grandeur through the occupation of North Africa and, moreover, that the failure to do so would lead other European states to seize the opportunity first and so gain an advantage: “Any people that easily gives up what it has taken and chooses to retire peacefully to its original borders proclaims that its age of greatness is over. It visibly enters the period of its decline” (Tocqueville 2001, 59). In the 1860s and 70s, Heinrich von Treitschke, a great admirer of Machiavelli, contemplated the “greatness of the State” and celebrated the greatness of Prussia in terms of its ability to absorb neighbors while writing that “All the great nations of history, when they have become powerful, have felt an impulse to stamp their character on savage nations” (Treitschke 1914, 56, 70, 171). Indeed, he concluded, “For Nations at the present day it is a matter of life and death to press on with their colonising activity.” Writing in 1883, in the Expansion of England, John Robert Seeley observed that England “has grown steadily greater and greater” as a consequence of its empire, which increased both its power and security (Seeley 1890, 1–2 and 13). In the twentieth century, Carl Schmitt, an admirer of Treitschke, was the author most closely associated with the idea that the state must expand in order to survive. In 1936, Schmitt (1936) wrote: “Famous academic textbooks on politics . . . treat mainly internal political constitutional questions, particularly the transmitted doctrine of ‘state-forms’ (Monarchy, Aristocracy and Democracy). Only in Heinrich von Treitschke’s Politik . . . is there a strong sense shown that the state must display its power and existence externally, if necessary, by means of war.” ⁵ In an early essay, he observed: “Does a ‘future state’, once realized, remain a state? The answer is difficult on account of the fact that every state that is to be consciously erected by humans, according to some state-ideal, in general has the tendency to spread itself over the entire Earth, to become ‘catholic’ in this sense” (Schmitt 2021, 192). Schmitt made an argument for states as the center of a new spatial and global order, and he placed the emergence of those states in the global order established by Europeans’ discovery of worlds new to them (Schmitt 2003 [1950], 130).

Twentieth- and twenty-first-century theorists of international relations, notably the “realist” school, shared the perception that the commitment of states to their preservation leads them into rivalry and, potentially, conflict with each other, followed by the conclusion that they therefore seek to augment their power and frequently find themselves in a “security dilemma” of escalation (Herz 1950; Mearsheimer 2001; Waltz 1979). John Mearsheimer’s summary of this perception barely deviated from an established tradition of expansionist thought:

Given the difficulty of determining how much power is enough for today and tomorrow, great powers recognize that the best way to ensure their security is to achieve hegemony now, thus eliminating any possibility of a challenge by another great power. Only a misguided state would pass up an opportunity to be the hegemon in the system because it thought it already had sufficient power to survive. (Mearsheimer 2001, 35)

Responding to cosmopolitan critiques of the state, recent apologists for the system of territorial sovereignty, notably Anna Stilz, have rightly pointed to certain “core values” provided by sovereign states: the realization by different peoples of their cultural, economic, and social concerns; basic justice; and collective self-determination. At the same time, it is argued that the external sovereignty of states must be limited “to respect the reciprocal sovereignty of other states” (Stilz 2019, 14). It is less clear what will ensure such respect. Grotius would have agreed with this defense of sovereignty and with the limits upon external sovereignty. He argued that states that destabilized the society of nations would be collectively punished by their peers, who would recognize the threat to their own preservation. Grotius made this critique, however, while also arguing for the right of the Netherlands to expand in order to preserve itself (Grotius 2006). The rules-based international order appears similarly to be honored as often in the breach as the observance.

While much modern political thought has continued to emphasize the necessity of expansion to maintain a state, nineteenth-century international law also revived the discussion of occupation in early modern natural law and the law of nations. Nineteenth-century international lawyers developed their arguments out of the works of Francesco de Vitoria, Hugo Grotius, Samuel Pufendorf, and Christian Wolff, who they believed to be relevant to a new epoch of imperial expansion. They rejected symbolic claims to property or sovereignty and insisted, instead, upon what they termed effective occupation. By the time of the conference in Berlin in 1884/85, where the Great Powers debated the partition of Africa, they legislated this principle in positive international law through treaties. The question that these nineteenth-century international lawyers remained divided upon, however, in common with their early modern predecessors, was whether property preceded sovereignty or flowed from it (Fitzmaurice 2014, 271–301).

The polar regions became the last (terrestrial) imperial project after the occupation of worlds new to Europeans had been exhausted. This new environment challenged the principles of effective occupation that had been worked out over the course of the nineteenth century. If the polar regions were to be subjected to the same rules that had been applied to, for example, Africa, the Americas, or Oceania—that is, that there must be a relatively intensive exploitation of resources and territory by a resident population in order for property and sovereignty to claimed—then it was clear that these regions must remain common (either as res communis, as Grotius would have the seas, or as negative community, as Pufendorf had argued) and therefore unclaimed or, potentially, unclaimable. The alternative argument, however—one explored in great depth which determined the fate of Greenland and Spitzbergen (both of which remained outside sovereignty in the first decades of the twentieth century)—was not so much as to abandon the rules of effective occupation but to adapt them to the different environment so that what constituted seizure and intensive exploitation of resources must be considered relatively.

In 1919, a verbal commitment from the Norwegian foreign minister, Nihls Claus Ihlen, to his Danish counterpart stipulated that in exchange for Danish recognition of Norwegian claims to Spitzbergen, Norway would recognize Danish claims to what was then called East Greenland, now Tunu. The 1920 Spitzbergen Treaty recognized Norway’s claim while giving rights of commercial access to all signatories. Denmark attempted to substantiate its claim to East Greenland in 1921 by excluding all foreigners, including Norwegian enterprises. Gustav Smedal, a Norwegian jurist and later a member of the Nasjonal Samling party, was one of a number of Norwegian National Socialists who advocated for Norwegian occupation of the area of East Greenland known as Erik the Red’s Land. Smedal observed that “increasing interest in Polar regions . . . the only large land areas which are still No-man’s-land (terra nullius)” was driven in part by “[t]he desire which exists in all strong political communities to extend their territories” (Smedel 1931, 8).

Smedal conceded that there was a difference between the Polar regions and previous domains of European colonization: “As a rule, more is required for exercising control in densely peopled territories than in territories sparsely peopled or uninhabited. The African Conference in 1884-85, and the Institut de Droit International in 1888, had more particularly in view territories with a great native population” (Smedel 1931, 33). The Berlin Conference had theorized Africa as territorium nullius, which meant that although it may be subject to property, it was void in terms of territorial sovereignty (Fitzmaurice 2014, 271–301). The term that Smedal, and the other national socialists, used for the polar regions was terra nullius. As Smedal put it: “From a legal point of view it is significant that the Polar areas are, to a great extent, still terra nullius, and that they are either uninhabited or have only a scanty population” (Smedel 1931, 6). Terra nullius was void in terms of both sovereignty and property (the Inuit peoples were not counted other than as a “dying race”), but importantly, it was negative community, as Pufendorf put it, rather than res communis. There was a sense, moreover, in which this new terra nullius could not be subjected to the same rules of effective occupation as had, for example, Africa. The Permanent Court of International Justice in 1933 recognized Denmark to hold sovereignty over Greenland. A group of jurists at Columbia University began working on the implications of that decision. On the one hand, they questioned whether it might be possible to use the concept of terra nullius to understand the whole history and character of European expansion (Keller 1938; Simsarian 1938, 111–128).

The debates over sovereignty in the polar regions, from the Spitzbergen Treaty in 1920 through to the Antarctic Treaty in 1959, represent the last zones of the planet to be brought into a system of international determination of their status. The final years of the polar expansion concluded with the beginning of decolonization and the collapse of European empires. At the moment the great powers found no further territory on earth suitable to their quest for grandezza, they shifted their attention to outer space. Moreover, the new focus of sovereign states upon space brought into view for the first time since the early modern period a vast and, in fact, unlimited sphere in which states could compete for resources and in which, at the same time, positive law claims were extremely weak. This new space could only be comprehended by returning to questions about the nature of property and sovereignty—that is, by returning to natural law. For the first time since the early modern period, natural law claims found a new domain. Writing in 1950, Carl Schmitt made the connection between the Europeans’ “discovery” of America, the development of international law, the fragmentation of that order with decolonization, and possible expansion into space, but he regarded the last step as fantastical: “The traditional Eurocentric order of international law is foundering today, as is the old nomos of the earth. This order arose from a legendary and unforeseen discovery of a new world, from an unrepeatable historical event. Only in fantastic parallels can one imagine a modern recurrence, such as men on their way to the moon discovering a new and hitherto unknown planet that could be exploited freely and utilized effectively to relieve their struggles on earth” (Schmitt 2003 [1950], 39). In quick succession, the Soviet Union launched Sputnik into orbit in 1957, the United States established a satellite in 1958, Yuri Gagarin orbited the earth in 1961, followed by Alan Shephard a month later, and in 1969 Apollo 11 landed men on the moon.

In 1958, the US National Security Council draft policy on outer space opened with the statement that: “The USSR has surpassed the United States and the free World in scientific and technological accomplishments in outer space, which have captured the imagination and admiration of the world. The USSR, if it maintains its present superiority in the exploitation of outer space, will be able to use that superiority as a means of undermining the prestige and leadership of the United States and of threatening U.S. security” (NSC 1958). In his 1962 Rice University address, President Kennedy invoked early modern English expansion when he declared: “William Bradford, speaking in 1630 of the founding of the Plymouth Bay Colony, said that all great and honorable actions are accompanied with great difficulties,” concluding “no nation which expects to be the leader of other nations can expect to stay behind in the race for space” (Kennedy 1962). The 1986 National Commission on Space, under Reagan’s presidency, was explicit in its report “Pioneering the Space Frontier” that expansion into space was a continued projection of the previous four centuries of European imperial expansion: “The Solar System is our extended home. Five centuries after Columbus opened access to ‘The New World’ we can initiate the settlement of worlds beyond our planet of birth. The promise of virgin lands and the opportunity to live in freedom brought our ancestors to the shores of North America. Now space technology has freed humankind to move outward from Earth as a species destined to expand to other worlds” (NCS 1986).

At the same time that expansion into space was imagined to secure the state through augmenting its power, both the United States and the Soviet Union feared that precisely this policy on the part of the other would lead to claims of sovereignty over the Moon or other parts of space. A 1958 National Security Council memo stated that “Discovery and exploration may be required to establish a foundation for the rejection of USSR claims to exclusive sovereignty of other planets which may be visited by nationals of the USSR,” although at this point the United States was nevertheless reserving its position on “whether celestial bodies in space beyond the earth are susceptible to appropriation by national control or sovereignty” (NSC 1958, 9 and 13). The implication was that either both would have to be engaged in a very expensive, and draining, space race, beyond the Apollo missions, or they would need to declare space off-limits to such ambitions through an agreement that it would not be claimable, either through occupation or symbolic gestures, and as such it would be res communis. By 1966, Henry Owen in the State Department Policy Planning Staff, wrote a memo for the Space Council in which he argued: “During the first ten years of the space age, we have frequently found ourselves in the real or apparent position of following the Soviet lead. Taking into account the fact that pre-eminence in space has been widely viewed as meaning broader pre-eminence in science and technology, we cannot afford to fall into an inferior position in the future. At the same time, extending the space race beyond the moon is not in itself a desirable foreign policy objective” (SC 1966, 1a). Cooperation was particularly attractive when the USSR appeared to be winning the race.

In September 1963, the US and USSR conducted negotiations on the “legal problems of outer space.” Both sides held remarkably similar positions. The Soviet Union declared that “Outer space and celestial bodies are free for exploration and use by all States” but that “[s]overeignty over outer space or celestial bodies cannot be acquired by use of occupation or in any other way” (Negotiations 1963). The American delegation proposed in response to make a “[s]tatement on the freedom of outer space and celestial bodies for exploration and use by all states on a basis of equality and in accordance with international law.” The idea of a res communis suited the interests of each side.

To make this case, both powers drew upon the history of international law and in particular on the reasoning behind freedom of the seas and the polar regions as a res communis. The first step in their reasoning was the ambitious claim that international law applied to the entire cosmos and all celestial bodies. The Soviet “draft declaration” included the statement that “the conquest of outer space shall be carried out in accordance with the principles of the United Nations charter and with other generally recognised principles of international law.” This question had already been settled two years earlier on December 21, 1961, as James Simsarian pointed out, when the General Assembly of the United Nations passed Resolution 1721 declaring that international law applied to space and celestial bodies (Simsarian 1963, 855). Simsarian had been trained in Columbia Law School under Philip Jessup and had contributed to the development of the concept of terra nullius, a term that members of the Columbia International Law seminar had employed to understand claims to title through occupation throughout the entire history of European empire (Simsarian 1938). In 1963, however, Simsarian concluded that space was not terra nullius but res communis—that is, it should remain common property and was not susceptible to claims of ownership or sovereignty (Simsarian 1963). In making this argument, he was in step with his former professor, Philip Jessup, who in 1959 published Controls for Outer Space and the Antarctic Analogy in the same year that the Antarctic Treaty had been concluded. That treaty was a triumph of the res communis idea, ensuring that the continent remain outside the sovereignty of any state and, moreover, that it be used “in the interest of all mankind,” language that was incorporated into the Outer Space Treaty eight years later. The idea of a res communis for space was also no less than the United Nations Committee on the Peaceful Uses of Outer Space, established in 1958, had already agreed, as had President Kennedy and Chairman Khrushchev in their correspondence (Simsarian 1963, 860). The salient point here is that the jurists, such as Simsarian and Jessup, who worked on the last wave of terrestrial expansion in the polar regions, were now writing the law of extraterrestrial expansion. The two spheres were connected not just by the extension of past law into the new realm but, as in this case, continuity in the people who had developed those laws. On the face of it, the agreement to establish a res communis was not consistent with the use of law to justify the expansion of the state. At the same time, however, it represented the projection of a legal regime into space and, as such, it had been adopted because it was believed to be consistent with the interests of the superpowers—as had been the case with mare liberum for the British empire—and because it was also believed to provide enough latitude for another regime in the future, which indeed proved to be the case.

The concurrence within the international community on the need for a res communis regime in space concluded with the “Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies,” otherwise known as the Outer Space Treaty (OST) in 1967. Article 3 of the treaty confirmed that all activities in space must be conducted “in accordance with international law” (OST 1967). Article 2 of the treaty states that “Outer Space, including the Moon and other celestial bodies, is not subject to national appropriation by claim of sovereignty, by means of use or occupation, or by any other means.” Article 6 of the treaty made it clear that states were responsible for all activities in Space “whether such activities are carried on by governmental agencies or by non-governmental entities in outer-space.” Article 1 of the treaty stipulated that the “exploration and use of outer space, including the Moon and other celestial bodies, shall be carried out for the benefit and in the interests of all countries, irrespective of their degree of economic and scientific benefit, and shall be the province of all mankind.”

Article 2 of the Outer Space Treaty, however, was ambiguous in its wording. In forbidding appropriation by claims of national sovereignty, by use or occupation, it left open a debate that had been conducted over the previous four hundred years: namely, whether property preceded sovereignty and was a reason for establishing sovereignty or whether it was a creation of sovereignty. While the OST forbade states from making claims to sovereignty through occupation, it did not declare whether a corporation, an individual, or some other entity (such as an international organization) could make claims to property in space. As early as 1969, the jurist Stephen Gorove argued that “the Treaty in its present form appears to contain no prohibition regarding individual appropriation or acquisition . . . an individual acting on his own behalf or on behalf of another individual or a private association or an international organization could lawfully appropriate any part of outer space” (Gorove 1969, 351). Nevertheless, the interpretation of Article 2 remained more a matter of hypothetical, rather than substantial, importance for the next thirty years because of the technological challenges of occupation and ruling out, as the implicitly OST does, symbolic claims to title.

Beginning in the 1990s, however, and increasingly in the past twenty years, jurists have become troubled by Article 2 of the Outer Space Treaty. The recent past has been marked by a shift in interest and investment in space due largely to two factors: firstly, a renewed great power rivalry, including the United States, on the one hand, and China and Russia, on the other; secondly, and perhaps more importantly, private corporations are now leading investment in space, compared with the state-led investment of the Apollo era. Those corporations have dramatically lowered the cost of launching a kilogram into space, making ventures more economically feasible, while both the Moon and Mars, as well as near-Earth asteroids, have been discovered to contain vast quantities of precious substances. At the same time, both the Moon and Mars have been shown to have reserves of water that can be used for fuel and oxygen. These combined factors have led to the various plans to establish “colonies” on the Moon and Mars by ventures based in the United States, leading a consortium of thirty-five “Artemis” countries, and also from China and Russia.

Once again, some corporations responsible for expansion into space exhibit an independence that reflects an ambivalence in their relationships with the states they are supposed to serve. One leading company, SpaceX, was founded with the goal of developing a colony on Mars. Anyone, such as the Ukrainian company Kyivstar, for example, who signs a contract for satellite internet services provided by Starlink, a subsidiary of SpaceX, must agree to the following clause:

For Services provided to, on, or in orbit around the planet Earth or the Moon, this Agreement and any disputes between us arising out of or related to this Agreement, including disputes regarding arbitrability (“Disputes”) will be governed by and construed in accordance with the laws of the State of California in the United States. For Services provided on Mars, or in transit to Mars via Starship or other spacecraft, the parties recognize Mars as a free planet and that no Earth-based government has authority or sovereignty over Martian activities. Accordingly, Disputes will be settled through self-governing principles, established in good faith, at the time of Martian settlement. ⁶

Regardless of whether one believes that SpaceX will fulfill its ambitions of colonizing Mars, it would be foolish to dismiss them. Whether empire is located in the state itself or in the corporation is once again uncertain, as it was in the age of the great chartered companies such as the East India Company. But perhaps the most startling aspect of this clause in Starlink’s contract is that we can see, once again, as in the days of the East India Company, a corporation has pretensions to being able to establish sovereignty itself, independently of any existing sovereign, and it can only make this claim because it believes itself not to be dependent for its existence on such sovereigns.

If colonies are established on the Moon and Mars, the key question for jurists has been who shall exercise jurisdiction; will property or sovereignty be established over the territory they occupy, or over a larger territory; will property be established over things that are produced in space; and can these ventures take place within the framework of the Outer Space Treaty? The Artemis project attempted to anticipate some of these questions by declaring that, while the Outer Space Treaty would be respected in terms of claims to sovereignty, it was nevertheless possible to establish “zones of protection” on the Moon. Any student of political thought might remark that protection is one of the first obligations of sovereignty, while a historian of empire would also notice the correspondence with nineteenth-century colonial protectorates. In 2015, partly in response to pressure from asteroid mining companies, the United States Congress passed the Commercial Space Launch Competitiveness Act, which declared “the right of U.S. citizens to engage in commercial exploration for and commercial recovery of space resources.” This means that any materials (excepting “biotic” life) seized in space by citizens or companies based in the United States would be the property of those persons (CSLCA 2015). The Act concluded with the words “the United States does not, by enactment of this Act, assert sovereignty or sovereign or exclusive rights or jurisdiction over, or ownership of, any celestial body,” suggesting that property can be seized where there is no sovereignty. The only caveat to that possibility was that, if it is true that property can be occupied where sovereignty does not exist, then it is not clear why an act by a sovereign power would be necessary to make that claim. A broader conclusion, however, would be that the tension between this claim, that property can exist without sovereignty, and interpretations of the Outer Space Treaty as excluding all property, transported space law back to the discussions over colonial law between the seventeenth and nineteenth centuries.

Luxembourg was the second country, in 2017, to pass a law protecting property in space, but unlike the United States, it does not require majority shareholding to be based in its own country (Luxembourg 2017). Russia followed suit in 2019 with similar laws. Luxembourg’s own space agency observes that the “The [Outer Space] treaty bans countries from appropriating celestial, outer space bodies, including the Moon. However, there is a lack of clarity about the ownership of metals, minerals and other resources that may be found there” (Luxembourg 2017). As a consequence, “This legal uncertainty now needs clarification.” Luxembourg, therefore, proceeded to clarify the situation through its own legislation (thereby attracting many space corporations to its own jurisdiction): “Luxembourg is the first European country . . . to offer a legal framework that secures property rights for space resources.” Ironically, what the state was doing was to legislate that it is possible to establish property where there is no sovereignty.

As we have seen, the connections between the development of space law and imperial law were not simply analogous—although the analogy was important—they were also direct insofar as jurists who had worked on the last epoch of terrestrial expansion transferred their concepts, such as terra nullius and res communis, to extraterrestrial expansion, while the perceived political necessity of expansion for states remained a constant. Jurists who engaged with space law in the past thirty years have perceived this connection between space and the colonial past, frequently portraying this connection as the model for future expansion into space, and for the laws of space rather than in terms of critique. This is not to suggest that such critiques have not been articulated. A number of jurists and others have pointed, with great concern, to the territorialization of space through the projection of international law while also pointing to the imperial associations of that projection (Grayling 2024; Manoli 2021; Pershing 2019; Tennen 2016; Utrata 2023). These critics generally support the 1967 Outer Space Treaty, and they take it to prohibit claims to property as well as sovereignty, suggesting that they regard property to be the creation of sovereignty. The historical alignment of that view with skepticism of expansionism is reflected in their work. They frequently also express a preference for a res communis regime in space without, perhaps, much awareness of the degree to which res communis arguments have been used historically, notably in relation to freedom of the seas, to support imperial ambitions and the interests of powerful states, notably the British empire (Somos 2025; Weststeijn 2025).

More commonly, however, journals that deal with space law have published numerous attacks on the principles of the Outer Space Treaty, notably concerning sovereignty as well as the obligation to share resources with all humankind. This is said to have led to a “tragedy of the anti-commons” where the treatment of space as common property that cannot be seized leads to the underutilization of a vast resource. These articles are frequently characterized by direct appeals to John Locke’s understanding of property in order to support the idea that property can be seized where there is no sovereignty and to the concept of terra nullius as a radical alternative to res communis.

The first task, as these jurists saw it, was to correct the mistaken characterization of space as res communis and to portray it, instead, as terra nullius or res nullius. In 2013, Benjamin Landry wrote, “The commercialization of outer space has been stunted by inefficiencies in the international laws” (Landry 2013, 524). “No state or private entity,” he wrote, “has been willing to bear the enormous cost of commercialization in part because international law prohibits national and, potentially, private appropriation, and even if the laws are interpreted to allow private appropriation, they require private entities to share some unclear quantity of returns (‘benefits’) with every state on Earth” (Landry 2013, 525). He proposes, instead, a regime in which “All of outer space would be classified as res nullius” (Landry 2013, 567).

As the space mining industry first began to be imagined, John Adolph argued that the concept of space as a common heritage of mankind in the Outer Space Treaty had a “chilling effect” on private investment (Adolph 2006, 969). He wrote, “With the prospect of making such astounding profits from space mining, the necessity for a working legal system that will preserve the property rights of miners and allow for the growth of the space mining industry is clear . . . the common heritage doctrine prohibits them from removing the resources they have found” (Adolph 2006, 976). Instead, Adolph argued, “The doctrine of terra nullius, coupled with acquisition by discovery, helped spur the colonization of the Americas during the sixteenth and seventeenth centuries. Imagine what Earth would be like if, in the sixteenth and seventeenth centuries, the Americas had been protected as the common heritage of all mankind, shielding the vast resources from colonization and sovereign claims” (Adolph 2006, 981). Putting aside the normative aspect of this account, the salient point is the imaginative connection between European imperial ventures, the law that was used to justify them, and the understanding of space in the twenty-first century.

Writing at the same moment, and also in an American law journal, Brandon Gruner made this connection between the future of space and the past of colonization the focus of his article, as was evident in the subtitle: “Incorporating nineteenth century first possession principles into the 1967 space treaty for the colonization of outer space in the twenty-first century.” Gruner argued: “These treaties rest in large part on the principle that outer space is res communis and not subject to national appropriation. While this approach is laudable in theory, it is problematic in application, as it fails to create an adequate incentive for space exploration and colonization” (Gruner 2004, 305–306). The idea of res nullius, on the other hand, enables possession: “The Americas were considered res nullius, and hence belonged to no one until a European nation claimed the land” (Gruner 2004, 336). These principles had been cemented in United States common law in the well-known case Johnson v. M’Intosh, whereby “Chief Justice Marshall reasoned that although Native Americans inhabited the New World, its lands were legally vacant because ‘to leave [Native Americans] in possession of their country was to leave the country a wilderness.’” The lesson to be drawn from Chief Justice Marshall’s judgement “and particularly applicable to space law—is the principle that all undeveloped land, even if settled by others, will be subject to the sovereignty of the civilized discoverer who will develop the land. Thus, acquisition of res nullius by discovery gives an incentive to the discovering nation to explore, exploit, and develop the newly-claimed land, as the discoverer is rewarded for his investment in the celestial property. Advocates of this first possession principle would abhor leaving the land in its native state and would declare such inactivity a misuse of the land” (Gruner 2004, 346). It did not take a huge leap of imagination to then conclude that: “declaring extraterrestrial lands as res nullius would signify that the heavens belong to no nation and all territory and resources are ripe for capture” (Gruner 2004, 344).

For Gruner, the imperial past taught the efficacy of a system of state-based discovery and sovereign claims, followed by parceling out of territory to adventurers who could demonstrate effective occupation. For many jurists, however, such a system was neither necessary nor desirable because the prohibition on sovereign claims in the Outer Space Treaty left open the possibility of making property claims. As Wayne White argued in 1997: “Article II of the Outer Space Treaty prohibits territorial sovereignty but does not prohibit private appropriation” (White 1997, 6). The implication of such arguments was the idea that property existed prior to sovereignty and that sovereignty is established in order to protect property. John Locke has frequently been invoked to support this Lockean claim along with a very Lockean interpretation of the colonial past. As Adolph observed: “Philosophers such as John Locke discussed the various approaches to property ownership and helped develop the idea of terra nullius where ‘land belongs to no one, until someone has mixed his labour with it’” (Adolph 2006, 981). Similarly, Alan Wasser and Douglas Jobes argued in 2008 that “the Outer Space Treaty does not ban private property” (Wasser and Jobes 2008, 44). At the same time, they claim that property on the Moon can be created through use and labor: “As John Locke wrote: ‘As much Land as a Man Tills, Plants, Improves, Cultivates, and can use the Product of, so much is his’” (Wasser and Jobes 2008, 49–50). Claims on the Moon “would only be based on true occupation and use of the land”: that is, they would only be made by “permanently inhabited settlements-made by people who are, by then, inhabitants of the Moon, and are no longer ‘Earthlings’” (Wasser and Jobes 2008, 50). This reimagining of American colonization leads to the parallel conclusion of colonies that will establish their own societies and independence.

Given the appropriateness of the argument that property precedes sovereignty to colonization, it is hardly surprising that we should find it revived again in the context of the space race, particularly in the past twenty years when corporations have been leading that race. When Wayne White argued that the “Outer Space Treaty prohibits territorial sovereignty but does not prohibit private appropriation,” he naturally perceived the utility to corporations of the idea that property can be established where there is no sovereignty: “Hence, private entities may appropriate an area in outer space or on a celestial body, although states may not” (White 1997, 6). Having argued that the Outer Space Treaty “does not ban private property,” Wasser and Jobes turn to “a major point of related debate,” which “involves what international law has to say about the legality of a private entity, such as a space settlement owned by a corporation or individual, claiming ownership of land on a celestial body like the Moon on the basis of ‘occupation and use.’” They argue that “current international law, and especially ‘the Outer Space Treaty,’ does appear to permit private property ownership in space and permit nations on Earth to recognize land ownership claims made by private space settlements, without these nations being guilty of national appropriation” (Wasser and Jobes 2008, 40–41).

It would be tedious to catalog all these arguments by contemporary jurists regarding space. They are numerous and repetitive, and they frequently fail to understand early modern natural law and figures such as Locke, as they twist these traditions to their own purposes. But their arguments do raise some important questions about our understanding of property, sovereignty, and empire in the past and the future. Similarly, the legal and political contexts for discussion of outer space over the past eighty years demonstrate some continuity with the law and politics of empire over the past four hundred years. The early modern logic that states need to expand in order to preserve themselves does not appear to have left us—this is not surprising because it was a logic that was rooted in the rise of the system of sovereign states. This expansionist ambition underpins the conceptualization of new space. That newly conceived space is outside positive law jurisdictions, and accordingly, contemporary jurists have returned to the natural law debates that were employed to conceptualize empire in the past. As such, they reveal that natural law and natural rights traditions have flourished where positive law is weak in its application to a space. The turn to natural law leads to questions such as: What is the relation of humans to nature? What is property? And what is sovereignty? These questions remain as unanswered and fractious today as they were for early modern Europeans. Any position we take on them has consequences—for example, the notion that property can exist where there is no law is tied to colonial arguments from the European empires. The most liberal account of property, and the one that has the strongest understanding of the rights of a pre-social individual, is the one that is most closely linked to expansionism. This vision gave agency not only to natural persons but to artificial persons, or corporations, as well. A similar, and largely derivative, vision in law is now helping to drive the expansion of states and corporations into space.

Given that these questions are largely metaphysical and ontological—they concern matters to do with the very nature of being—it is very unlikely that they will be resolved. What is more likely, however, judging by the experience of the past, is that certain actors, such as corporations, will employ the concepts that are most suitable to the justification of their own ambitions. This tendency is already apparent in the mobilization of arguments about property existing where sovereignty has not been established. Actors, whether corporations or states, shop for the concepts that best suit their expansionist ambitions. Our ideological environment is formed by that process: the triumph of liberalism in the nineteenth and twentieth century cannot be untangled from its success in justifying European empires.

What appears to be an anarchical environment will nevertheless produce a new wave of empires that strengthen space-faring states: the anarchy of ideas facilitates empire. At the same time, a number of other actors, notably companies, will establish their own empires with various degrees of autonomy from the states that served as their platforms. Some of those may, in time, collapse back into those states, as did the East India Company; others may go on to form the basis for independent societies, as did the Massachusetts Bay Company. Those societies will be political experiments; new constitutions will be erected on their foundations. It remains to be seen whether they repeat the vices of past empires or emulate the virtues of free societies. Those people who would like to see space remain a common heritage of humankind, unable to be appropriated, are likely to see their wishes surpassed by events and by the weight of history. But if they wish to stop this juggernaut, they need to address not just the immediate plans for the habitation and development of space but the strange metaphysics of the system of states and their agents, the corporations. Modern empires began with the formation of modern states. As long as we live with states, we will live with empires.