Liberalism (in the classical sense) and its more austere cousin libertarianism, are fundamentally doctrines that put personal and political freedom at the heart of things. Liberalism is committed to the freedom and equality of all people, but for the classical liberal and the libertarian, this is typically understood as freedom from government and social interference so that one can exercise one’s freedom to live the life of one’s choosing. Equality is crucial in securing freedom insofar as we understand equality as equality of fundamental rights to non-interference. In this way, so-called “classical” liberalism is a species of liberalism that emphasizes the importance of freedom and focuses on equality of rights rather than, for instance, equality of outcomes.

It is strange, then, that classical liberalism and libertarianism are so often understood as being doctrines primarily concerned with defending property. This confusion is, as a historical matter, the result of monomaniacal focus on property rights by critics as well as defenders of the view. Of course, property rights will be included in any plausible list of fundamental rights. Property rights are really, after all, primarily non-interference rights over specific domains. Libertarians, for instance, often talk about “self-ownership,” but what they mean is a basic right of a person’s body against trespass and interference. These rights are especially important, but they do not exhaust the realm of rights.

It is a commonplace to argue, as Thomas Nagel did in an early review of Robert Nozick’s epoch-making Anarchy, State, and Utopia, that the libertarian and classical liberal focus on rights is “without foundations.” Although this criticism is fundamentally mistaken, it is an unsurprising allegation given the preferred intuitionistic method of many of the most important philosophical libertarians.

Rather than use intuitionism or consequentialism, I argue that libertarians and liberals should embrace a contractual method of justification for the core notions of freedom, equality, and rights that define the theory. The core rights that define the freedom and equality of members of a free society are or would be, on this view, the result of an agreement between rational individuals for the purpose of mutual benefit. Or, to use John Rawls’s evocative formulation, the contractual model of a free society envisions it as a “cooperative venture for mutual advantage.”

Understood this way, the social contract is a justificatory rather than explanatory tool. As many have noted, the state of nature and contractual consent are not accurate descriptions of the history of political organization. This criticism, however, misunderstands the basic idea behind social contract theory: to model how a genuinely voluntary and mutually beneficial society would be structured. If rational individuals have reason to endorse and comply with the rules in a contractual society, we can then use the contractual test to evaluate the rules and institutions of our own society. The social contract acts as a tool to evaluate existing and possible social rules and institutions.

Contractual theory, pursued this way, aims to bring the mutually beneficial power of market exchange to social governance. But simply substituting the market for social norms and political organization will not usually be enough. As David Gauthier notes in Morals by Agreement, “before Smith’s invisible hand can do its beneficent work, Hobbes’s war of every man against every man must first be exorcized” (85). Markets require a foundation in basic norms of trust and the assurance that one’s rights are secure. This requires, at least initially, credible enforcement and governance mechanisms. This governance can be achieved in any number of ways, however, not all of which require explicit political institutions. The making and enforcing of social norms does not always require the existence of a leviathan state. Because of this, contractarianism is not committed to statism in the customary sense. The test of mutual benefit is just as relevant to informal governance institutions and social norms as it is formal political institutions. Indeed, the long-term project of the libertarian contractarian should be to investigate how forms of genuine self-government can realize, in modern societies, the contractarian goals of voluntariness and mutual benefit.

There are good reasons for libertarians to also be contractarians and to justify libertarianism contractually. The contractual approach helps to solve two perennial problems in libertarian and liberal theory. The first is the foundational problem of whether to base libertarian conclusions on some deontological basis (e.g., natural rights) or to adopt a consequentialist justification. The second is how to square a strong presumption against coercion with any system of collective choice and governance, that is, how to adjudicate between the anarchist and minimal government strands in libertarian thought. Contractarianism provides an elegant solution to both of these problems.

Without going into too much detail, the contractual approach preserves a focus on the consequences of political institutions that many find appealing in consequentialist or utilitarian theory without relying on dubious value theories or ignoring either the separateness or individuality of persons. Similarly, the contractual method, based on rational agreement, provides a justification for rights that doesn’t rely on controversial foundations. This, as I argue more fully in “Social Contractarianism,” makes the contractual approach uniquely attractive to libertarians who have been traditionally locked into antimonious disputes between consequentialist and rights-based justifications of libertarianism.

I also argue that the contractual approach can dissolve another traditional dispute between classical liberals and libertarians; whether the implication the implication of their strong defense of freedom and non-interference makes government impossible. That is, whether libertarians are really committed to anarchism. I argue that contractarianism of the sort that I defend allows one to be both a philosophical anarchist, while still admitting that there might be a role for some (properly justified) political institutions. The contractual libertarian can admit that there is no moral obligation or duty to obey the state, but that in a free and open society with institutions that can meet the contractual test, there are good reasons to endorse the laws and social norms of such a society.

Liberalism, and especially libertarianism, is unique because it posits no social goal and claims no prerogative to decide how and why we should live our lives. The metaphor of a social contract is a radical and evocative image of this basic idea. To organize ourselves while preserving our freedom and equality, we must contract. Agreement is the only basis of a free society. These agreements must be voluntary and reflect our perceived interests. A society built on this model would be as close to a truly voluntary society as we could ever hope. The real benefit of contractarianism for the libertarian, who already embraces the vision of a voluntary society, is that it provides a framework for moving away from the traditional antinomies of libertarian thought into a progressive program for developing and analyzing the institutions and orders of a free and open society.

John Thrasher is currently a Lecturer in Philosophy at Monash University in Melbourne, Australia. In August 2018 He will join the Smith Institute for Political Economy and Philosophy at Chapman University in Orange County, California. He specializes in political philosophy, normative ethics, and decision theory, focusing on the relation of individual practical rationality to social rules, as well as the way those rules are organized into systems of norms and institutions. He is especially interested in how recent work in moral psychology and experimental economics can inform our understanding of how to improve our institutions of self-governance. His work has been published in Nature Communications, The American Journal of Political Science, Philosophical Studies, Synthese, The Journal of Moral Philosophy, Political Studies, Social Philosophy & Policy.