This essay is part of a series on Liberalism. See the full collection here

In a recent Public Discourse article Phillip Muñoz offers a sympathetic critique of Patrick Deneen’s First Things article “Unsustainable Liberalism.” While Muñoz shares Deneen’s concerns about the corrosive effects of a kind of liberalism, he argues that Deneen fails to distinguish between “temptations that liberalism makes possible” and “a healthy and proper form of liberalism.” This latter form of liberalism, Muñoz suggests, is “based upon a return to our founding principles, principles grounded on truths about and a deep respect for nature.”

It is easy to see why Deneen’s critique of liberalism might be attractive to social conservatives, yet Muñoz is right to resist it. For Deneen’s argument strikes not only at liberalism, but at reason itself as a ground of moral argument. This is evident in his Public Discourse reply to Muñoz, in which he proposes biblical Christianity as an alternative to liberalism. Leaving aside the viability of Deneen’s proposal, it completely overlooks the greatest inheritance of the Western moral tradition: the natural law.

Unfortunately Muñoz repeats this same error in his critique of Deneen. Although he appeals to the Declaration of Independence, he never once mentions the natural law, despite the fact that it is explicitly appealed to in the opening sentence of the Declaration. Instead he emphasizes the Lockean elements of the Declaration. Deneen is right in his reply to Muñoz: If American liberalism is primarily Lockean, then American social conservatism is in serious trouble.

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Fortunately American liberalism is not primarily Lockean. Deneen writes as though the truly liberal reforms of the American founding—the institution of republican forms of government, the prohibition of titles of nobility, the elimination of religious establishments and primogeniture, the abolition of slavery, the admission of truth as a defense in cases of libel, and so on—put America on the sure path to abortion on demand and redefining marriage. But this is absurd. No signer of the Declaration of Independence thought that in affirming equality and natural rights he was also affirming a voluntarist moral philosophy, and every one of them would be as troubled by the state of modern America as is Deneen.

Now it can be and often is argued that the American Founders were simply naïve, that they did not realize they were sowing the bad seed of Lockean liberalism into their traditional forms, a seed whose growth in time would eventually strangle the delicate flower of true liberty. But there is not sufficient warrant for this conclusion except by an invalid post hoc, ergo propter hoc form of reasoning, which is only plausible in the absence of an alternative explanation.

To see that alternative, however, we must break free of the tendency to treat liberalism as a monolithic concept resting upon a moral framework of radical autonomy and a legal framework of moral neutrality with respect to competing notions of the good. This form of liberalism (which can be called modern liberalism) is a latecomer to the liberal tradition, and finds little support in the prior tradition of liberalism, and no support in the principles of the American founding.

This tendency to regard modern liberalism as liberalism simply is particularly noxious for a political order based upon reason, because liberalism regards itself, and is generally regarded as, the political representative of reason, against which there can only be appeals to private sources of knowledge such as prejudice, tradition, intuition, or revealed religion.

But this is to concede far too much to modern liberalism. As Robert George shows in The Clash of Orthodoxies and elsewhere, the arguments of modern liberals on matters such as abortion and marriage have obvious weaknesses that can be seen on the grounds of reason itself, without appealing to other sources of knowledge.

Biblical Christianity, on the other hand, when cut off from the natural law tradition, lacks the resources to address some of the most basic moral issues, like slavery. Deneen alludes to this fact almost in passing, but I’m afraid he does not give it sufficient weight. As the late Eugene Genovese often pointed out, biblical evidence favored slavery. This was not a problem for Genovese, who was a Catholic, but it was a huge problem for Christians who accepted the Bible as the only moral authority and who were also convinced that slavery is wrong, and this divergence between the text of the Bible and their moral convictions played some role in driving evangelical Christians of the nineteenth century into the arms of liberal Christianity.

The task for social conservatives, then, is not to abandon liberalism tout court, but to recover and restore what Muñoz calls the “healthy and proper form of liberalism,” which is exemplified in the principles of the American founding. But if it is not primarily Lockean, what is that liberalism?

Following the proposal of Christopher Wolfe, we might call it natural law liberalism. This new name does not mean that it is a new thing, any more than the word liberalism itself, which was not used until the nineteenth century, implies something new about Hobbes, Locke, or the American founding. It does not matter that none of the American founders ever articulated the principles of natural law liberalism in a systematic way, any more than that the Apostles never formulated the Nicene Creed. But as John Cardinal Newman said of the Apostles, the American Founders did not build better than they knew, they knew more than they said.

We will see natural law liberalism best in the historical light of the competing liberalisms from which it draws, and from which it differs: social contract liberalism and classical liberalism.

Social contract liberalism grows out of the Anglo-Enlightenment tradition, and is associated with Hobbes, Locke, and more recently Robert Nozick. It attempts to deduce justified political authority from a set of universal, abstract premises: All men are by nature free and equal and possess inalienable rights, and the consent of the governed therefore is required for political authority to be just.

There are two main problems with social contract liberalism. First, it is based upon an a priori abstraction from the actual social, historical, and dependent nature of human beings and the exigencies that nature requires (must children, for example, consent to the authority of their parents?); second, its “math” simply doesn’t add up. As Elizabeth Anscombe, Hannah Pitkin, Robert Nozick, and Murray Rothbard, each in his or her own way has shown, contract theory simply cannot justify the kind of robust political authority most social contractarians think it can. (Nozick and Rothbard applaud this fact). The logical end of contract theory, consistently developed, is some form of anarchy: minarchism for Nozick and anarcho-capitalism for Rothbard.

Classical liberalism grows out of the Scottish Enlightenment tradition, and includes thinkers such as Montesquieu, Adam Smith, David Hume, Francis Hutcheson, and, more recently, F. A. Hayek. Classical liberalism is more sensitive than contract liberalism to the fact that human beings are by nature social, historical, and dependent animals, and it illuminates the ways in which emergent, spontaneous orders are forms of knowledge that cannot be achieved by centralized direction. Classical liberals therefore show how liberty, community, and tradition can be complementary, and how political authority can be justified as a necessary means of solving coordination problems in a given society.

Whereas social contract liberalism errs in the direction of Descartes’s rationalism, abstracting human beings from their embodied, historical condition, classical liberalism errs in the opposite direction. Following Hume’s skepticism, classical liberals emphasize the social and historical nature of human beings so far as to deny them any access to universal, trans-historical truth. Classical liberals therefore tend to favor pragmatic over principled approaches to moral and social problems.

In short, both social contract liberalism and classical liberalism are inherently unstable. Each affirms valuable but partial truths in a way that tends to preclude self-correction by the other. Thus social contract liberalism affirms the truths of human equality and natural rights, but rests them on an abstract Cartesian foundation that undercuts the social ties and traditions that bind human beings together. Classical liberalism, on the other hand, acknowledges the importance of those implicit social ties, but rests them on a Humean or skeptical foundation that undercuts the ability to defend them with arguments when they are attacked.

The result is that both liberalisms, as Deneen suggests, possess an inner dynamic that pushes them in the direction of modern liberalism, and both lack the inner resources to resist that push. Although the roots of modern liberalism can be found in the writings of Kant, Hegel, and J. S. Mill, its most influential American expositor is John Rawls. Rawls ingeniously (and, it must be said, not always coherently) combines both contractarian and classical liberalism into a comprehensive philosophical system that is indebted to both forms of liberalism, even as it departs markedly from them.

There is no need to reiterate the problems with modern liberalism. The point here is to set in relief what is distinctive about natural law liberalism. According to Thomas Jefferson, the Declaration of Independence is not simply a translation of Lockean social contract theory. “All of its authority,” he wrote in a letter to Henry Lee, “rests on the harmonizing sentiments of the day, whether expressed in conversation, in letters, printed essays, or in the elementary books of public right, as Aristotle, Cicero, Locke, Sidney, &c.” Locke is there, but so is Aristotle.

We have here a clue to what is great about American liberalism: It does not rest upon the writings of a single theorist, but draws from the best thought of the western tradition of right, classical, medieval, and modern, in a way that is still genuinely liberal. Elements of both social contract theory and classical liberalism are there, but their foundations rest upon the metaphysical realism and ethical framework of the pre-modern tradition (Aristotle and Cicero).

When one steps away from the Declaration’s Lockean elements, one begins to notice and give due weight to things like the natural law in the opening paragraph of the Declaration of Independence and the appeals to “divine Providence” and the “Supreme Judge of the World” at the end. These bookends of the Declaration not only frame the argument of the document, they frame its content as well, placing rights within the context of duties, and duties within the context of a more comprehensive metaphysical and moral order.

The Declaration does not spell out the elements of that metaphysical and moral order in detail, but implicit in its language and in the other principal writings of the American Founding are convictions such as the following: Reason, properly understood, is a necessary and sufficient condition for political life. Reason can discover and has discovered within tradition permanent truths, including human equality and natural rights. But equality and rights cannot be properly understood apart from the positive basic goods that they serve and that constitute real human flourishing, goods like knowledge, friendship, and beauty. The achievement of these goods depends upon a plurality of associations (families, churches, educational, commercial, and cultural institutions). It also depends upon an overall political association and political authority that protects, supports, and coordinates the activities of individuals and associations for the sake of each and all (the common good). Finally, the entire social and political order and the goods it serves require a degree of solidarity, citizenship, and virtue in its members.

This last point is particularly important. Between its metaphysical and moral bookends the Declaration acknowledges the authority of prudence, the only moral virtue explicitly mentioned in the document. This is fitting, for prudence is the intellectual virtue that makes possible the realization of moral principles in concrete and contingent circumstances. And as Aristotle makes clear, this is not ordinarily, or even principally, a deductive process from self-evident first principles, but involves experience, deliberation, and good judgment.

To see the importance of this virtue, consider the limited provisions for slavery that made the original Constitution, and indeed the eventual abolition of slavery, possible. The wisdom and justice of those provisions is evident to those who possess the virtue of prudence. The fact that most Americans see in those provisions only weakness and moral hypocrisy shows how far they have abandoned Aristotle and Aquinas for Kant. And a similar point might be made on a host of other moral questions facing us today.

Contra Muñoz and Deneen, the solution to the political and moral crisis of our time does not lie in abandoning liberalism or defending Lockeanism. It rests in the recovery of the natural law liberalism that informed America’s founding principles, and that animates some of the great liberal minds of our own time. The Founders, C. S. Lewis, Leo Strauss, John Paul II, and Benedict XVI find in natural law liberalism a public philosophy that is true to reason, to nature, and to Christian belief. Only this kind of liberalism is truly sustainable.