A couple weeks ago Robert A. Levy, chairman of the Cato Institute, co-authored a Washington Post op-ed with John D. Podesta, president of the leftish Center for American Progress, in which they urged the courts to invalidate the will of Californians and residents of the 30 other states where voters have rejected same-sex marriage.

The involvement of Cato, a self-described libertarian think tank, on the side of those pushing for same-sex marriage is disturbing on two counts. First, Levy is urging judges to legislate from the bench, to overrule the citizenry, who have expressed their will in the clearest way possible: through direct referendum. Second, he argues for his position, both here and in an op-ed back in January in the New York Daily News, on the basis of equality rather than liberty.

Libertarians have a long history in the struggle for gay rights. In the early 1970s the Libertarian Party took a principled stand in support of repealing state sodomy statutes. These were the laws that were used to justify police persecution of gay people, such as the raid that resulted in the Stonewall riots in June 1969 — the event that marked the beginning of the gay rights movement.

The principle underlying libertarian opposition to the sodomy laws is clear: private sexual acts between (or even among) consenting adults are just that — private. The government has no business prohibiting, regulating or interfering in any way in the consensual sexual activities of mature adults. This is an extension of the more general libertarian principle that any voluntary transaction between two adults should be free from government interference as long as that transaction doesn’t demonstrably harm a third party.

In urging repeal of the sodomy laws, libertarians were careful to make it clear that they opposed laws banning private discrimination against homosexuals, whether it be in employment decisions, public accommodations, housing, or in any other context. The right of two adults to engage in a voluntary transaction subsumes the right not to engage in any transaction with anybody for any reason.

Unfortunately, many libertarians today — and this includes the Libertarian Party and others as well as Cato Institute — are not as consistent in upholding these principles as were the libertarians of the 1970s. In truth, the “libertarian” case for so-called “marriage equality” is not only fundamentally flawed, it is dishonest.

First of all, we already have “marriage equality”. Gays and lesbians have as much right to marry as straight people. Marriage, by definition, is the union of one man with one woman. Although other cultures and some religions have sanctioned the marriage of one man to more than one woman, in western Christendom, of which the United States is a part, marriage unites two people of the opposite sex. Furthermore, that was the law in every state until 2004, when the Massachusetts Supreme Judicial Court ruled that restricting marriage to heterosexual couples violates the state constitution. If a gay man wants to marry a willing woman, or a lesbian wants to marry a willing man, no law is stopping them from doing so.

Changing marriage laws so that two people of the same sex may marry each other isn’t extending a “right” to marry. It is redefining marriage.

Second, everybody, regardless of sexual orientation, already has practically all the fundamental rights supposedly associated with marriage. Do two people want to have sexual relations, even relations that are considered “unnatural”? Ever since the U. S. Supreme Court’s 2003 Lawrence v. Texas decision invalidating all state sodomy laws, they have that right.

Do two people want to live together under the same roof, sleep in the same bed, merge all their personal affairs in joint bank accounts, etc.? Nobody is stopping them.

Do you want to assign either medical or durable power-of-attorney to someone else so he or she can make medical, legal or financial decisions for you? You have that right. Want to make an unrelated person of the same sex your heir or the beneficiary of your life insurance policy? You have that right, too.

But, say proponents of same-sex marriage, only those in heterosexual marriages can file joint tax returns, collect a spouse’s Social Security benefits after the spouse’s death, or leave one’s estate to another without its being taxed.

True, but these are not rights in any valid sense of the term. They are benefits, and, through various state and Federal laws, over 1,000 of them are conferred on married couples. And this is where the “libertarian” argument for same-sex marriage fails.

Levy agrees that “marriage today should be a private arrangement, requiring minimal or no state intervention”. But then, quoting the 14th Amendment to the U. S. Constitution, he asserts, “whenever government imposes obligations or dispenses benefits, it may not ‘deny to any person within its jurisdiction the equal protection of the laws'”.

The error in Levy’s reasoning should be obvious. There is no violation of the 14th Amendment here, because, as was noted above, a homosexual may avail him- or herself of the same benefits by marrying a willing member of the opposite sex, just like any heterosexual.

If there is a violation of the Constitution, then it is the restriction of these benefits to married people, whether they are in same-sex or opposite-sex unions. For example, under Federal law there is no estate tax on assets passed at death to a spouse. This denies equal protection to unmarried people. Why shouldn’t a single person be able to leave his or her estate, tax-free, to a mere friend?

There is an even more compelling reason why libertarians should not be supporting same-sex marriage. As I noted above, libertarians in the 1970s explicitly rejected bans on private discrimination against homosexuals. Unfortunately, such bans now exist. Once gay unions are recognized as “marriage”, we can expect anti-discrimination lawsuits against, say, employers who, for religious reasons, refuse to provide spousal benefits to same-sex couples while providing them to heterosexual couples.

We already have a foretaste of what to expect in this regard. eHarmony.com, an online dating service founded by the Christian psychologist Dr. Neil Clark Warren, was forced to create a dating website for gays and lesbians in response to an anti-discrimination complaint filed by a gay man.

But the main reason libertarians should resist the drive to redefine marriage is the foundational role marriage plays in human societies.

Marriage is primarily about children. It provides a safe environment for rearing them and also provides for the orderly transfer of wealth from one generation to the next.

In the Judeo-Christian tradition, as recounted in the Book of Genesis, marriage was humanity’s earliest social institution, predating the beginning of civil government. Marriage probably originated as agreements between families, with parents and other relatives of the two spouses standing ready to enforce the agreement, if necessary.

Society acquired an interest in marriage because it provides an unambiguous way to assign responsibility for children so that they would not become a burden on the community. Even today, the husband of the mother at the time of birth is assumed to be the child’s father, even if DNA tests prove otherwise, and is held responsible for his or her support — which is why fidelity remains an essential part of the marriage relationship, even if it is observed in the breach.

Traditionally, the marriage relationship was regarded as beyond the reach of the State. What went on in the marital home was none of the government’s business and, barring extreme circumstances like physical endangerment to children, the government usually stayed out. Even as the State asserted increasing control over business and other areas of life, marriage remained a sanctuary from government intrusion. This is one of the reasons the political Left has always been hostile to the institution.

In recent years, governments have increasingly abandoned their laissez-faire policy toward marriage and, beginning with the spread of no-fault divorce laws in the 1960s, have increasingly worked to undermine it.

Even so, the essential character of marriage, what makes it unique among all human institutions, has remained: it is the union of one man and one woman, ideally for life. Redefining marriage will destroy this uniqueness and, in fact, will destroy marriage itself because its very definition will have been destroyed. When this happens, we will have lost our last refuge from overreaching government.

There is a libertarian position on marriage and it is this: the government should stay out of it. Marriage should be a private contract between consenting parties, sanctioned by religious authorities if the couple so choose.