Synthesizing Natural Rights and Contractualism
by Kevin Vallier
Libertarian political philosophy in the analytic tradition nears the half-century mark. Libertarian theorists have produced sophisticated defenses of limited government and individual liberty, but these defenses diverge in fundamental ways. The divergences reflect incompatible views about the nature and source of justice itself. This philosophical diversity may point toward a more complete understanding of libertarian justice.
Two recent works capture these divergent strands. Billy Christmas’s Property and Justice advances a natural rights libertarianism that derives a complete theory of justice from the single principle of non-interference. Nick Cowen’s Neoliberal Social Justice builds a contractualist case for classical liberal institutions that takes seriously the epistemic limitations plaguing any attempt at social organization. These books push their respective traditions to new levels of sophistication.
Christmas shows how a single, clearly specified natural right can generate a complete account of justice that avoids the ad hoc multiplication of principles plaguing other approaches. He derives complex conclusions about property, exchange, and governance from a simple foundation in human nature. Cowen demonstrates how contractualist reasoning, updated with insights from robust political economy, can justify classical liberal institutions without appeals to controversial metaphysical claims. He grounds libertarian conclusions in what rational agents would accept given realistic assumptions about human knowledge and motivation.
Yet theoretical purity exposes fundamental limitations. Christmas’s natural rights approach struggles to provide action guidance in our decidedly non-ideal world. The theory tells us what perfect justice looks like, but not how to approach it from current conditions. More troublingly, its rigid compossibility requirement rules out enforceable duties to aid the vulnerable, a conclusion that strains moral credibility. Cowen’s contractualism faces its own puzzles. If the burdens of judgment extend to economic reasoning as Cowen suggests, why think rational contractors could agree on any particular institutional framework? The very epistemic limitations that motivate his approach threaten to undermine it.
These limitations might seem to force a choice between principled impracticality and pragmatic compromise. Natural rights libertarians must embrace conclusions that shock moral common sense. Otherwise, they abandon the theoretical purity that makes their view distinctive. Contractualist libertarians face a parallel problem. They must ground their institutions in agreements that their own epistemic commitments suggest are impossible. Otherwise, they give up the realism that motivates their approach. This dilemma has shaped decades of libertarian theorizing.
I propose a different path. Rather than choosing between natural rights and contractualism, we should recognize that these approaches operate at different levels of political theory and under different circumstances of justice. The apparent conflict between them dissolves once we see that justice itself can be circumstance-relative without thereby becoming relativistic. Different social conditions call not merely for different applications of unchanging principles but for different principles suited to those conditions. A complete libertarianism can incorporate the genuine insights of both traditions while transcending their limitations.
The circumstances of justice shape not just the application but the very content of just institutions. In small, homogeneous communities where people share fundamental values and face manageable coordination problems, Christmas’s pure natural rights regime might be both feasible and optimal. The simplicity of social relations allows rights principles to translate directly into institutional arrangements without extensive intermediation. But in large, diverse societies characterized by profound disagreement and dispersed knowledge, Cowen’s contractualist approach becomes necessary. The complexity of social coordination requires institutions that emerge from mutual accommodation among people who reason differently.
This variation in principles need not collapse into relativism any more than the use of different scientific theories at different scales implies that physics is relative. Just as quantum mechanics and general relativity both describe objective features of reality at their appropriate scales, natural rights and contractualist theories might both capture genuine aspects of justice under their proper circumstances. The challenge is explaining how these different principles relate systematically rather than accidentally.
The federal model I develop provides such a framework. At the foundational level, certain natural rights constrain all political arrangements regardless of circumstances. These rights are grounded in features of human agency that transcend particular social contexts. They establish boundaries that no community may cross. But within these constraints, different communities may implement different specifications of justice suited to their circumstances. The federal structure enables this diversity while providing mechanisms for coordination among communities operating according to different principles.
This approach can resolve longstanding puzzles in libertarian theory. It explains how we can maintain principled commitments to individual liberty while acknowledging the need for pragmatic accommodation to social complexity. It shows how natural rights can ground political philosophy without generating conclusions that strain moral credulity. It demonstrates how contractualist reasoning can justify stable institutions despite deep disagreement. The diversity of libertarian theorizing reflects not confusion but a more profound truth about the circumstance-relative nature of political justice.
Developing this synthesis requires careful engagement with both Christmas and Cowen on their own terms. We must understand what drives their theoretical choices and what problems their approaches solve before we can see how they might fit together. The synthesis cannot simply split the difference or assign each theory its own domain by fiat. It must emerge from a deeper understanding of how the circumstances of justice shape the content of just institutions.
Christmas’s Natural Rights Minimalism
Contemporary natural rights libertarianism faces a dilemma. Beginning with plausible claims about self-ownership or property acquisition, theorists either add principles to handle problem cases until the elegant foundation disappears, or they stick to a single principle and generate counterintuitive conclusions. Billy Christmas’s Property and Justice attempts to avoid proliferation through natural rights minimalism. Christmas derives a complete theory of justice from a single principle and achieves remarkable theoretical economy. Yet this economy generates conclusions that reveal deep tensions within the natural rights approach.
Christmas’s innovation begins with his conception of rights. Rather than starting with a bundle of natural rights that must somehow be rendered consistent, he identifies a single “claim-right to non-interference in one’s non-interfering activities” (11). This formulation does double duty. It specifies what we have a right to (non-interference) while simultaneously limiting that right (only in non-interfering activities). The reflexive structure builds the solution to rights conflicts into the specification of rights themselves. If I can only claim non-interference in my non-interfering activities, then any activity that interferes with you automatically falls outside my protected sphere.
This approach elegantly solves problems that plague other natural rights theories. Consider property acquisition, a notorious source of complexity in libertarian thought. Locke required a proviso about leaving “enough and as good” for others. Nozick worried about the long-term effects of appropriation. Rothbard struggled to specify precisely how labor establishes ownership. Christmas cuts through these complexities by denying that property acquisition requires any special principle beyond non-interference (89). When I use an object in a way that doesn’t interfere with your ongoing activities, I acquire rights to continue that use. The temporal priority of non-interfering use establishes property claims without further theoretical apparatus.
The power of this minimalism becomes clear when Christmas addresses the compossibility problem. A system of rights serves its conflict-resolution function only if the rights it specifies can all be exercised simultaneously (25). Rights that conflict in practice fail to provide the guidance we need from a theory of justice. Many purported natural rights theories founder on this requirement. If I have a right to life that includes positive claims to life-preserving aid, and you have a right to your labor and property, our rights conflict when I need your resources to survive. Christmas’s single principle avoids such conflicts by construction. The principle only protects non-interfering activities, and interference with one person’s activities cannot be non-interfering. Genuine rights conflicts cannot arise.
Yet this theoretical elegance comes at a price that Christmas himself acknowledges only partially. The restriction to negative rights of non-interference rules out any enforceable positive duties to aid others (105). Christmas tries to soften this conclusion by noting that his theory doesn’t prohibit charity or social norms promoting mutual aid. It merely denies that such aid can be mandated as a matter of justice. This move preserves theoretical consistency but at considerable cost to moral plausibility. The parent who refuses to feed their infant violates no rights on Christmas’s account. The infant’s need for food doesn’t establish a claim to the parent’s labor or property. The wealthy community that watches neighbors starve while hoarding surplus commits no injustice, even if their actions are vicious.
Christmas might respond that his theory does recognize subsistence rights of a sort. People have rights to engage in subsistence activities without interference (103). If I’m gathering berries to survive, you cannot justly prevent me. But this negative subsistence right offers cold comfort to those unable to secure their own subsistence. The infant, the severely disabled, and the temporarily incapacitated cannot exercise negative subsistence rights. Christmas’s theory thus faces a dilemma. Either it must acknowledge that justice offers nothing to the genuinely helpless, a conclusion that strains credibility. Or it must complicate its elegant structure with additional principles that threaten the minimalism that makes it distinctive.
The problem runs deeper than concern for the vulnerable, though that concern alone might suffice to reject the view. Christmas’s minimalism also struggles with what we might call the problem of practical guidance. A theory of justice should help us navigate from our current, decidedly unjust circumstances toward more just arrangements. It should rank alternatives, identify priorities, and guide reform efforts. Christmas’s theory, focused entirely on specifying perfect justice, offers no such guidance (159). It tells us that massive current holdings are unjust, rooted as they are in historical interference, but not what to do about it. It identifies the injustice of state institutions but not how to move toward better arrangements.
This practical emptiness stems from the same minimalism that generates theoretical elegance. By refusing to incorporate any principles beyond non-interference, Christmas cannot say whether moving from unjust situation A to unjust situation B represents progress. Both involve interference; neither is just; the theory remains silent. The only guidance it provides is the ideal endpoint, a society of pure non-interference that seems impossibly distant from current realities. Christmas acknowledges this limitation and characterizes his view as purely ideal theory. But this acknowledgment doesn’t solve the problem. A theory of justice that cannot guide action in unjust circumstances has limited value for political philosophy.
These limitations point toward the need for help from other theoretical traditions. Christmas has shown us what perfect libertarian justice might look like in its purest form. The crystalline clarity of his vision illuminates the structure of rights and their relationship to human agency. But this purity prevents the theory from engaging with the realities of political life. Just as a perfectly frictionless plane exists only in physics textbooks, a society of pure non-interference exists only in philosophical abstraction. To build a complete libertarian theory, we need approaches that can bridge the gap between ideal theory and day-to-day implementation problems.
Cowen’s Epistemic Contractualism
Where Christmas offers crystalline principle, Nick Cowen provides pragmatic engagement with social complexity. His Neoliberal Social Justice takes seriously a challenge that natural rights theorists often slight: the profound limitations on human knowledge that complicate any attempt at social organization. Cowen weds Rawlsian contractualism to insights from robust political economy and develops a classical liberal political theory that grounds familiar libertarian institutions in epistemic humility rather than metaphysical certainty. This approach solves problems that pure natural rights theories cannot address, yet it generates new puzzles about the foundations of political agreement.
Cowen’s starting point is deceptively simple. What would Rawls’s theory of justice yield if we incorporated realistic assumptions about human behavior and social knowledge? (3) Rawls himself operated with relatively optimistic assumptions about the possibility of economic planning and bureaucratic management. His ideal of property-owning democracy or liberal socialism assumed that democratic institutions could effectively direct economic activity toward egalitarian ends. Cowen argues that these assumptions cannot survive engagement with the knowledge problems that plague all attempts at social coordination.
The argument proceeds through what Cowen calls Robust Political Economy (RPE), an approach that tests institutional proposals against realistic assumptions about human limitations (7). These limitations include not just the familiar problems of self-interest and opportunism but more fundamental constraints on what any person or institution can know. Following Hayek, Cowen emphasizes that the knowledge required for economic coordination is not merely dispersed but often tacit, contextual, and constantly changing. No central authority, however well-intentioned, can gather and process the information required to direct a complex economy effectively.
This epistemic argument transforms the case for markets. Rather than grounding economic freedom in natural rights to property or self-ownership, Cowen sees markets as discovery mechanisms that generate and coordinate knowledge no individual possesses. Prices communicate information about relative scarcity and preference intensity. Profit and loss reveal which projects create value and which destroy it. Competition discovers new ways of meeting human needs that no planner could have anticipated. The market economy serves not merely individual freedom but collective rationality under conditions of irreducible ignorance.
What makes Cowen’s approach distinctively contractualist is his extension of these insights to the Rawlsian framework. He argues that rational contractors behind the veil of ignorance, if they understood the knowledge problems facing any society, would choose classical liberal institutions. They would do so not from ideological commitment to markets but from recognition that alternative arrangements cannot deliver their promised benefits. The contractors would see that attempts at extensive economic planning or redistribution founder on informational constraints regardless of the good intentions behind them.
This move is both clever and problematic. Clever, because it turns Rawls’s apparatus toward conclusions he would have rejected, showing that his own methodology might support classical liberalism once we update its empirical assumptions. Problematic, because it raises questions about what contractors behind the veil could actually know and agree upon. If the burdens of judgment extend to economic reasoning as Cowen suggests, why think contractors would converge on any particular interpretation of the knowledge problem?
Cowen’s most innovative contribution lies in his extension of the burdens of judgment to economic questions (59). Rawls famously argued that reasonable people will disagree about religious, philosophical, and moral questions due to the complexity of evidence, the vagueness of concepts, and the diversity of life experiences. These “burdens of judgment” explain why liberal societies must tolerate deep disagreement about ultimate values. Cowen argues that similar burdens apply to economic reasoning. Reasonable people disagree about whether stimulus spending helps or harms the economy, whether minimum wages benefit or hurt workers, and whether industrial policy promotes or retards development. These disagreements stem not from ignorance or irrationality but from the same factors that generate moral and religious pluralism.
This insight has radical implications that Cowen only partially develops. If economic reasoning faces burdens of judgment, then appeals to economic efficiency or market optimality cannot serve as neutral grounds for public justification (153). Just as liberal states cannot justify policies by appeal to controversial religious doctrines, they seemingly cannot justify institutions by appeal to controversial economic theories. Cowen suggests that this very controversy supports markets, since markets allow people to act on their diverse economic beliefs without forcing agreement. But this argument seems to privilege one controversial economic view over others. Markets enable beneficial pluralism, but perhaps they produce harmful chaos requiring democratic coordination.
The tension becomes acute when we consider the role of democracy in Cowen’s framework. He wants to preserve democratic institutions while limiting their scope, particularly in economic matters. But if the burdens of judgment apply to economics, why should democratic majorities accept such limitations? They might reasonably believe that democratic planning would work better than markets if given a real chance. Cowen cannot simply assert that they’re wrong without abandoning his commitment to taking pluralism seriously. Yet allowing unlimited democratic authority would undermine the classical liberal institutions his whole theory aims to justify.
This points to a deeper issue about the compatibility of epistemic humility and institutional confidence. Cowen’s view depends on two claims that stand in tension: (1) we should be humble about our ability to know what economic arrangements work best, and (2) we can know that classical liberal institutions work better than alternatives. The first claim grounds his critique of planning and redistribution. The second grounds his positive case for markets. But if our epistemic limitations are as severe as the first claim suggests, how can we be confident in the second?
Cowen might respond that this tension dissolves at the institutional level. We cannot know in advance which particular economic arrangements will serve human welfare, but we can know that discovery mechanisms work better than planning mechanisms, given our ignorance. This meta-level knowledge about institutional properties doesn’t require the object-level knowledge that planners would need. Yet this response raises its own puzzles. How do we know that markets are the best discovery mechanism? Mightn’t democratic experimentation discover better institutions? The appeal to discovery mechanisms threatens to become circular if markets are both the method of discovery and the discovered solution.
These problems don’t negate Cowen’s contributions but rather highlight the need for additional theoretical resources. His epistemic approach captures crucial insights about the knowledge problems facing any attempt at social organization. His extension of contractualism to include realistic assumptions about human limitations enriches the Rawlsian framework considerably. But the framework cannot stand alone any more than Christmas’s natural rights minimalism can. Each approach illuminates aspects of libertarian justice while casting shadows elsewhere. Understanding how they might work together requires developing a more complex view of how the circumstances of justice shape institutional possibilities.
The Circumstances of Justice Reconsidered
The path from recognizing the complementary limitations of Christmas and Cowen to synthesizing their insights runs through a reconceptualization of the circumstances of justice. Both theorists, like most contemporary political philosophers, treat these circumstances as fixed background conditions that make justice relevant and determine its content. Since they differ on the circumstances, they differ on the content of justice. But I would argue that the circumstances of justice instead determine how abstract principles of justice receive their specification. If I am right, we can develop a more general form of libertarianism that incorporates both natural rights and contractualist insights without reducing one to the other.
To see why circumstances matter for specification and not just content, consider the historical development of the concept. Hume identified the circumstances that make justice both necessary and possible: moderate scarcity and limited benevolence. In conditions of extreme abundance or perfect altruism, he argued, justice would be unnecessary. In conditions of extreme scarcity or pure selfishness, it would be impossible. Justice emerges in the middle ground where conflicts over resources arise, but can be resolved through general rules. For Hume, these observations supported a conventionalist view where justice consists in beneficial social practices that emerge from human interaction.
Rawls modified this account by adding what we might call the “circumstances of subjective justice” – the fact that people hold conflicting conceptions of the good life. This addition reflected the modern reality of deep pluralism that Hume’s more homogeneous society didn’t fully face. For Rawls, this pluralism didn’t change the content of justice but did affect its justification. We need principles that people with different comprehensive doctrines can accept, leading to his famous distinction between comprehensive and political liberalism.
But Rawls may not have taken his own insight far enough. If the circumstances of justice include deep disagreement about values, and if this disagreement extends to conceptions of justice itself as Rawls later acknowledged, then we face a puzzle. How can we identify uniquely correct principles of justice that apply regardless of whether people accept them? The standard answer is that justice is objective even if people disagree. But this answer becomes problematic when the disagreement concerns the very criteria for identifying just institutions.
This is where my proposal diverges from standard approaches. Rather than seeking principles of justice fixed by circumstances, we should recognize that different circumstances call for different specifications of abstract principles. This doesn’t mean justice is relative in any objectionable sense. The circumstances of justice determine how abstract principles receive their specification. The key to avoiding relativism lies in identifying mechanisms that objectively transform social circumstances in ways that make different specifications appropriate.
Cowen’s theory can accommodate this pluralism about justice through political decentralization. The crucial mechanism is self-sorting. By decentralizing legal authority to states or localities and allowing persons to move freely between them, citizens can find legal regimes closer to what they have most reason to accept. This self-sorting process not only moves people to legal orders they prefer but pressures smaller political bodies to alter their laws to attract citizens. If people self-sort into polities where others share their values, those polities will have more shared reasons. Using shared reasons in politics will be easier and less burdensome. This mechanism objectively changes the social facts at different scales of political organization.
Consider how self-sorting creates distinct circumstantial domains. At the local level, self-sorting produces relative homogeneity. People who share fundamental values and face limited coordination problems cluster together. The circumstances that result include shared understanding of property conventions, direct accountability through repeated interaction, low information costs for monitoring compliance, and rough agreement about the priority of liberty. In these objectively homogeneous circumstances, Christmas’s principle of non-interference might genuinely capture how abstract principles of justice receive their specification. The elegant simplicity of natural rights principles can translate directly into workable institutions where people have genuinely sorted themselves into value-compatible communities.
At the federal level, by contrast, self-sorting produces managed diversity. The larger political order must accommodate the multiple communities that have formed through sorting. Here, the circumstances are objectively different: deep pluralism about values, dispersed knowledge across communities, and fundamental disagreement about the relative importance of liberty, equality, and other political values. Under these transformed circumstances, Cowen’s contractualism becomes not just practical but necessary for how justice receives its specification. Justice requires not implementing predetermined principles but establishing fair procedures for ongoing negotiation among communities that reason differently. The contractualist approach asks what institutions reasonable people would accept given their different values and limited knowledge, which varies with the objective level of diversity produced by sorting.
This answers the obvious objection: doesn’t this circumstance-relative view collapse into relativism? No, because different specifications are determined by objective social circumstances produced by self-sorting, not by arbitrary preference or mere convention. The mechanism of exit and sorting creates real, measurable differences between local and federal circumstances. Local homogeneity is an objective fact about shared values and reduced burdens of judgment. Federal diversity is an objective fact about pluralism and increased coordination challenges. Different specifications apply because the social facts are objectively different, not because communities simply declare their preferred arrangements just by definition.
This view requires distinguishing between foundational and institutional principles. Foundational principles reflect features of human agency that transcend particular contexts: the capacity for rational choice, the separateness of persons, and the importance of voluntary cooperation. These generate minimal universal constraints on any system of justice. No community may treat persons as mere resources, ignore their capacity for choice, or impose arrangements through pure force. But within these constraints, the specific institutional principles that govern property, exchange, and political authority can vary based on circumstances.
The variation isn’t arbitrary but follows intelligible patterns. As communities grow larger, direct democracy becomes infeasible and representative institutions emerge. As they grow more diverse, consensus on substantive values becomes impossible, and procedural agreement becomes crucial. As information problems multiply, centralized direction fails and decentralized coordination mechanisms become necessary. These aren’t just practical accommodations but reflect how abstract principles of justice receive different specifications under different circumstances.
Both Christmas and Cowen get part of the story right. Christmas illuminates how abstract principles of justice should operate when consensus about justice is feasible. In these circumstances, his vision of compossible rights achieved through non-interference represents a feasible moral ideal. Cowen illuminates how abstract principles of justice apply under pluralism and dispersed knowledge. His contractualist approach captures how rational agents would respond to deep disagreement and epistemic limits. But it presupposes rather than generates the foundational principles that make contractual agreement morally significant.
Understanding justice as circumstance-relative doesn’t diminish its objectivity but rather improves our understanding of what objectivity means in political philosophy. The mechanism of self-sorting creates objectively different social circumstances at different scales, and abstract principles of justice receive different specifications relative to these circumstances. This move opens theoretical space for synthesizing approaches that seem incompatible when treated as universal theories competing for the same logical space.
We can understand this framework through what I have elsewhere called the open society model. The open society accommodates deep disagreement about justice itself, not merely about the good. This accommodation is necessary because the same factors that generate disagreement about comprehensive doctrines also generate disagreement about conceptions of justice. Rawls identified how the complexity of evidence, the vagueness of concepts, and the diversity of life experiences lead reasonable people to disagree about religious and moral questions. These same factors apply with equal force to political questions. Citizens will disagree not just about what makes life worth living but about what makes political arrangements legitimate.
The open society manages this deeper pluralism through a crucial institutional distinction between stable constitutional rules and robust institutional rules. Constitutional rules are higher-order rules that specify how we settle upon first-order legal and institutional rules that apply directly to behavior. In an open society, constitutional rules must be stable enough to preserve the social conditions that foster experimentation. But first-order institutional rules should be robust rather than stable in the traditional sense. They should be able to achieve new equilibria after being challenged by social innovators and allow for discovery and improvement over time.
Toward a Federalist Synthesis
The federal framework operates at three distinct levels, each with its own philosophical foundation and institutional logic. At the foundational level, certain minimal constraints apply universally based on features of human agency that transcend circumstances. These constraints rule out slavery, systematic violence, and forcible prevention of exit. They don’t constitute a complete theory of justice but rather establish boundaries within which such theories can operate. Think of them as side constraints that any legitimate institutional arrangement must respect rather than goals to be maximized or principles to be directly implemented. This is the deepest layer of stable constitutional rules, the limiting principle of the open society.
Within these constraints, the communal level allows groups to implement their preferred specifications of justice at scales where circumstances permit. A group of Christmas-style libertarians might establish a community based purely on non-interference, with no taxation, regulation, or positive duties beyond what voluntary agreement establishes. Property rights would follow from historical patterns of non-interfering use. Disputes would be resolved by tracing who initiated interference. The elegant simplicity that seems utopian at the societal scale becomes workable where people share fundamental commitments and interact repeatedly.
Other communities might implement different specifications. A Cowen-style classical liberal community might establish market institutions supplemented by social insurance, funded through taxation, that its members accept as legitimate. Democratic procedures would determine the extent of public goods provision and regulation, constrained by constitutional protections for economic liberty. Some communities might adopt more egalitarian arrangements or extensive commons. Others might experiment with novel forms of property. The federal structure permits any specification that respects foundational constraints.
The inter-communal level emerges to handle relations between communities operating according to different specifications. This level necessarily operates through contractualist logic, since communities can’t appeal to shared substantive principles of justice. They must find mutually acceptable terms of interaction despite their different internal arrangements. At scales where people share thick conceptions of justice, those conceptions can directly govern. At scales where they don’t, procedural agreement becomes necessary. This pattern vindicates the circumstance-relative approach: different specifications apply at different scales based on objective social conditions.
Several mechanisms enable peaceful interaction across philosophical boundaries. Trade relations require only mutual recognition of possessions, not agreement about the deep justification for property rights. A Christmas community that views property as a natural right can engage in exchange with a Cowen community that regards it as a conventional institution. Each respects the other’s holdings for its own reasons. Disputes between members of different communities require neutral procedures rather than contested principles. Federal courts can apply minimal foundational constraints to handle inter-community conflicts without imposing any community’s full specification of justice on others.
The federal structure depends crucially on robust exit rights. Exit plays three essential roles in making philosophical federalism work. First, exit enables the self-sorting mechanism that objectively transforms circumstances at different scales. Without genuine freedom to move between communities, people cannot cluster with others who share their values, and the circumstantial differences between local homogeneity and federal diversity cannot emerge. Second, exit serves as a primary mechanism for public justification when voice fails. Following Hirschman’s classic analysis (1970), social change can occur through voice, where persons openly express concerns and demand institutional change, or through exit, where persons leave institutions they dislike or disagree with. Exit mechanisms can move the law into closer alignment with what is publicly justified for citizens. Justified laws create satisfaction and stability. Unjustified laws create dissatisfaction that can be expressed and ameliorated by exit. Political officials who want to keep their citizens will change the law to meet citizens’ needs, at least when officials must compete with other polities or provinces.
Third, exit incentivizes more careful deliberation about which laws should apply to each person. Citizens seldom have a causally significant impact on policy outcomes through voting, so their incentive to deliberate well is weakened. They may be rationally ignorant of political knowledge required for effective political decision-making. Exit deliberation functions differently. Each person decides whether to exit, and her exit choice will have a considerable causal impact on which laws affect her. She has an incentive to deliberate more carefully about relocating than voting. Most people deliberate more about which house to buy than which politician to support. Exit can increase the degree to which legal policy formation is based on good reasoning, since the law will sometimes be responsive to the exit choices of citizens.
This disciplining function cannot be overstated. People dissatisfied with their community’s approach can seek alternatives rather than fight for control. This possibility pressures communities to deliver on their promises. A natural rights community that degenerates into a propertarian oligarchy loses members to more egalitarian alternatives. A democratic community that stifles innovation through excessive regulation loses entrepreneurs to more libertarian options. Competition reveals which approaches work under which circumstances, not through abstract philosophical argument but by attracting and retaining members. The federal structure harnesses the discovery mechanism of competition not merely for economic goods but for specifications of justice themselves.
But this picture faces serious objections that require careful attention. First, the problem of territorial allocation: how do communities acquire legitimate jurisdiction over territory? If we start from anything like current distributions, we build massive injustice into the foundation. If we propose redistribution, we need principles for doing so that don’t beg the question in favor of one specification of justice. This problem doesn’t have a clean solution, but it’s not unique to the federal approach. Any libertarian theory must grapple with the legacy of historical injustice.
Second, the problem of externalities and spillovers: what happens when one community’s arrangements affect others? A community that pollutes shared watersheds or maintains military forces that threaten neighbors creates conflicts that the federal structure must resolve. Here, the minimal foundational constraints do real work. The principle against initiated aggression rules out imposing costs on others without compensation or agreement. Federal institutions can adjudicate disputes about externalities without imposing comprehensive solutions.
Third, the problem of internal minorities: what about those born into communities whose principles they reject? The right of exit provides crucial protection, but only if it’s genuinely available. Communities can’t make leaving so costly that members become effectively trapped. This requires not just formal freedom of movement but portable property rights, access to information about alternatives, and protection for those attempting to leave. Federal oversight of exit rights prevents communities from becoming prisons.
Fourth, the stability problem: can a system incorporating such different specifications remain stable over time? This is perhaps the most serious objection, as history suggests that ideological diversity often leads to conflict as groups attempt to universalize their preferred arrangements. The challenge is explaining how coordination can occur without a shared specification of justice. If communities operate according to fundamentally different specifications, what prevents the system from fragmenting into chaos or consolidating through conquest?
The stability challenge has a straightforward answer. Communities have an incentive to respect minimal federal constraints because doing so allows peaceful trade and interaction with other communities. Exit disciplines communities that violate these constraints by allowing members to leave for alternatives. Federal institutions provide neutral coordination points that communities can follow without sharing ultimate justifications. A Christmas community and a Cowen community need not agree on the deep foundations of property rights to follow the same dispute resolution procedures when their members interact. The system remains stable not through a comprehensive agreement but through mutual recognition that respecting minimal constraints serves each community’s interests.
These challenges are real but not insurmountable. More importantly, they arise for any attempt to manage pluralism about justice, not uniquely for the federal approach. The alternatives face greater problems: imposing one specification of justice on everyone or accepting perpetual conflict. The federal structure at least offers hope for peaceful coexistence and mutual learning among people who understand justice differently.
By providing institutional space for diverse experiments in justice, the federal structure respects the depth of reasonable disagreement about political arrangements while maintaining the minimal constraints necessary for peaceful coexistence.
Conclusion
The federal structure also addresses persistent criticisms of libertarianism from outside the tradition. Critics charge that libertarianism neglects community, but the federal structure explicitly provides for communal self-governance according to shared values. Libertarians can answer concerns about social justice by pointing to the possibility of egalitarian communities within the system. The charge that libertarianism offers only negative freedom misses how people gain positive freedom to live under institutions that match their convictions. These responses don’t require libertarians to abandon their principles but rather to understand them more broadly.
Most importantly, the federal structure embodies a distinctively libertarian approach to managing disagreement about justice itself. Rather than empowering majorities to impose their vision or philosophers to deduce the correct answer, it enables people to live according to their own understanding while respecting others’ right to do likewise. This represents libertarianism’s most profound insight: that peaceful cooperation doesn’t require comprehensive agreement, only mutual respect for the space to pursue diverse visions of the good life.
Christmas and Cowen provide the essential ingredients for this synthesis. Christmas shows us what principled commitment to liberty looks like in its purest form. His vision of justice through non-interference captures a moral ideal worth pursuing where circumstances permit. Cowen shows us how to reason about institutions under realistic constraints. His emphasis on knowledge problems and institutional robustness provides essential tools for navigating complexity. Neither alone suffices, but together they point toward something greater.
This synthesis doesn’t prove that libertarianism is correct, only that different libertarian approaches might be correct under different circumstances. It doesn’t resolve all tensions between natural rights and contractualism but shows how they might coexist productively. It doesn’t provide a blueprint for immediate implementation but offers a path for gradual development. What the synthesis does offer is a new way forward for libertarian political philosophy that escapes sterile debates between incompatible universal theories. By embracing circumstance-relativity and federal experimentation, libertarians can develop approaches adequate to the reality of deep pluralism while maintaining principled commitment to human liberty. The result won’t satisfy purists of any stripe, but it might actually work.
Kevin Vallier is Professor of Philosophy at the University of Toledo. Send him mail.
Isonomia Quarterly 