It cannot be repeated often enough: The issue dividing conservatives and libertarians is not whether there should be a public philosophy by which we are governed, but which philosophy should govern us, conservatism or libertarianism.

The “conservatism” that Professor Wenzel describes frightens even me. Fortunately it bears little resemblance to the American conservatism I am defending. Wenzel’s libertarianism, on the other hand, is Descartes with a Burkean face. Beneath the modest surface lies a rationalist principle that threatens the very foundations of free government.

American conservatism seeks to conserve the principles of the American founding. Those principles are based upon a steady and sober recognition of the complexities of human nature, and of a respect for the accumulated wisdom of centuries that have arisen in response to those complexities. They are rooted in the “Laws of Nature and Nature’s God,” laws that are not discovered a priori, but are won from reflection and experience, and which limit and guide the will. These laws of nature are the only foundation for free government. Whenever I use the word “conservative,” this is what I mean.

Our Constitution is a magnificent institutional framework for realizing these principles of justice. On no plausible reading can it be regarded as a libertarian document. The enumerated powers go well beyond the harm principle, and the Tenth Amendment acknowledges the reserved powers of the states. One does not need to be a libertarian to oppose the unconstitutional expansion of the national government; one only needs to be a localist, a decentralist, a Constitutionalist.

Start your day with Public Discourse

Sign up and get our daily essays sent straight to your inbox.

Libertarianism’s Burkean face professes respect for the Constitution. In Wenzel’s words, it “trusts institutions that help generate and transmit knowledge”; “eschews our limited reason in favor of reason nestled within tradition”; and “recognizes the need for virtue and self-governance.” Conservatives are ready to applaud.

But then Descartes strikes through the mask, demanding that the social order be made subject to a single, revolutionary, universal abstract principle. The harm principle is libertarianism’s cogito, its Archimedian point with which to move the world.

These two identities, Cartesian rationalism and Burkean traditionalism, cannot coexist. They are in fact the opposite and extreme terms of the modern predicament. Rationalism reduces reason exclusively to a priori, mathematical or logical truths, and traditionalism, reacting to rationalism, repudiates reason altogether for the sake of local and particular attachments.

Conservatism denies that rationalism is the only form of reasoning, or that reason is hostile to local and particular attachments. By affirming classical forms of reasoning that were unjustifiably repudiated by modern philosophy and science (analogy, epagoge, dialectics, etc.), conservatism possesses the intellectual resources to give both reason and tradition their rightful due while avoiding the errors of rationalism or traditionalism.

Wenzel repeatedly mischaracterizes conservatism as resting upon “assertions of private preferences,” but he offers no evidence to support this claim. Conservatism rests on the capacity of reason to discover truths that are in principle accessible to every mature human being. The conservative case against slavery, like the conservative case for marriage, rests upon public arguments and evidence that every human being in principle can recognize and acknowledge.

Wenzel further contends that conservatives fail to appreciate the knowledge problem. But Wenzel commits a category mistake here by falsely applying the “knowledge problem” in economics to moral knowledge. These two forms of knowledge are of a fundamentally different order.

The “knowledge problem” in economics arises from the fact that the information required for the best use of resources (natural or human) is widely dispersed and in principle beyond the capacity of any human mind to possess as an integrated whole. Moral knowledge, however, is not concerned with the relative value of scarce resources; it is concerned with the proper ends, goods, and principles of human action that constitute human flourishing.

The decentralized price mechanism is truly a “marvel” (to use Hayek’s term) in its ability to solve the knowledge problem. For this and other reasons, conservatives support the free market. But the price mechanism cannot tell us whether to prefer prostitutes to pencils, and any society that does so will not be free for long.

The fully reasonable judgment that certain actions (such as commerce in sex or highly addictive drugs) are contrary to human flourishing does not necessarily entail that they must be prohibited by the law. Even a superficial glance at the principal writings from the natural law tradition makes this clear.

In the first place, the requirements of the natural law are not always clear, and our understanding of the law is subject to development.

In the second place, even when the requirements of the natural law are clear, this does not necessarily mean that the human law should enforce them. The conservative fully agrees with Wenzel that state actions often have negative unintended consequences on the common good, and that this may be a good reason to refrain from legal prohibition.

Finally, conservatism affirms as one of its central truths the primacy of civil society. Human flourishing is not achieved in the state, but in a plurality of natural associations and authorities, beginning with the family. These associations, as the late John Paul II wrote, “stem from human nature itself and have their own autonomy, always with a view to the common good.”

But what is the common good? For Wenzel, the “only common good” is “a broad institutional framework within which individuals can peacefully cooperate.” This framework, he suggests, must be neutral with respect to competing conceptions of the good. Anything else is a violation of individual liberty.

Here again is the typical libertarian sleight of hand, which presents libertarianism as the neutral alternative to a partisan conservatism. But libertarianism is not neutral in principle or in effect.

In principle, the libertarianism ethic rests upon a voluntarist (or autonomous) notion of the self (what Wenzel calls “methodological individualism”). According to this notion, the self is prior to and outside of the ends it chooses. We do not choose ends because they are good; they are good because we choose them. This leads to a moral claim that no association or authority may make valid claims upon a human being unless that human being has explicitly consented to them. To treat any human being otherwise is to sacrifice his or her individual rights to the private preferences of another individual or group of individuals.

But the principle is clearly false. How many children consent to be under the authority of their parents? Do parents who coercively restrain their toddlers from running into a busy street violate the harm principle? Do citizens have enforceable obligations to support the framework of institutions Wenzel commends by taxation? How about the common defense?

I take it that Wenzel is not a rational anarchist, that he believes that both parental authority and political authority, within due limits, are justified, even when those under those authorities did not consent to them. But what is Wenzel’s justification for these authorities? Something more than the harm principle is required, but Wenzel never hints at what it might be.

Conservatism, on the other hand, is based upon an essentialist understanding of the self. Human beings desire things because they are good, and the achievement of these goods depends upon a number of conditions, including security, wealth, character, education, and freedom. These conditions constitute the common good, and they cannot be acquired without the assistance of political authority, as well as the authority of the family and other civil institutions.

In effect, the libertarian harm principle protects the freedom of some to violate the rights of others. As social libertarian Ronald Dworkin frankly acknowledges, protecting the right of pimps, prostitutes, and pornographers to commercialize sexuality, for example, would “sharply limit the ability of individuals consciously and reflectively to influence the conditions of their own and their children’s development. It would limit their ability to bring about the cultural structure they think best, a structure in which sexual experience generally has dignity and beauty, without which their own and their families’ sexual experience are likely to have these qualities in less degree.” No serious person can argue that the repeal of traditional obscenity laws in all fifty states by unelected federal judges has not had the effect Dworkin describes.

Reader take note: These are individuals being harmed, not reified social wholes. And so it is not true, as Wenzel says, that “individual liberty is not a main concern of conservatism.” Conservatives value individual liberty as much as libertarians, but they deny that freedom from coercion is the only form of liberty. When it is abused to obstruct the liberty of others to live according to the truth, and to undermine the moral and cultural conditions required for a free society, it is unjust and no longer deserves the protection of the law.

In the end it is libertarians who are guilty of social engineering. The earliest defenders of classical liberalism—John Locke, Edmund Burke, Adam Smith, or whomever you choose—never dreamed that by opposing mercantilism and protectionism they were promoting the elimination of traditional morals legislation. They knew that a free society depends upon a certain moral character and that law plays an important though subsidiary role in securing that character. Classical liberals were not libertarians. They advocated the free market, not the total market.

It was the utopian socialists of the nineteenth century who were the first advocates of free love, open marriage, and the elimination of traditional morals legislation. Lenin, not Locke, was the first to introduce no-fault divorce to the world. The effects on society were so disastrous that Stalin was forced to shore up marriage by restoring many of the traditional provisions. This has not prevented libertarians from promoting the elimination of legal marriage altogether, despite overwhelming evidence correlating divorce and cohabitation to crime, poverty, failure in school, alcoholism, drug abuse, physical harm, mental and emotional illness, depression, and suicide.

Progressivism is the American version of European socialism, and today’s progressives understand that central economic planning and radical moral autonomy go hand in hand. In buying into the latter part of the progressive agenda, libertarians unwittingly promote the former. In their legitimate fear of Orwell’s 1984, they ignore the lessons of Huxley’s Brave New World.

Finally, Wenzel draws from Public Choice Theory to argue that political institutions cannot provide for true deliberation. Public Choice Theory assumes (purely for methodological purposes) that “the interest of [a person’s] opposite number in the exchange be excluded from consideration” (to quote James Buchanan). This assumption is an important corrective to the opposite assumption that human beings miraculously become public-spirited when they hold political office. Worked into a theory, it offers good reasons for being suspicious of political solutions to social problems.

But this assumption cannot be the basis for a complete understanding of human nature or of politics without being viciously circular. One cannot demonstrate that politics is about maximizing private preferences by assuming it in one’s premise. And as a premise it leaves a good deal to be explained. Why, for example, does empirical evidence show a closer correlation between ideology and voting than between self-interest and voting? Or why do we object to the buying and selling of votes?

“If men were angels,” Madison famously writes in Federalist 51, “no government would be necessary. If angels were to govern men, neither external nor internal controls on government would be necessary.”

Libertarianism would have us believe that men are such devils that no government should be allowed, and at the same time are such angels that character, virtue, and liberty will arise “spontaneously” from mere market processes. But human beings are neither devils nor angels. They need government in order to be free, and they need freedom in order to govern well. This is not the Jekyll and Hyde of libertarianism; it is the paradoxical truth of the human condition that lies behind conservatism. We ignore it at our peril.