The state doesn’t care if the bride and groom love each other. There are no questions about a couple‚s affections when granting a license. No proof of passion is required. Why? Because marriage isn’t about love.

Yes, love may be the reason some people get married, but it isn't the reason for marriage. It may be a constituent of marriage, but it isn't the purpose of marriage. Something else is.

5. “Marriage is constantly being redefined.”

The definition of marriage has not been in flux in the way people suggest. In fact, marriage itself has not been redefined at all. Because there have been variations on the theme does not mean there has been no theme. From the dawn of civilization marriage has always been between men and women.

There have been changes. Historically some have been denied marriage (e.g., the young, the genetically aberrant, and interracial couples). Others were allowed to marry more than once, either consecutively (divorce and remarriage), or concurrently (polygamy). Spousal rights have altered and traditions have evolved. But marriage has still been marriage. And spouses have always been male and female.

To say something has changed is to say some core thing has remained the same. When an old curtain is changed into a work smock, or an irresponsible bachelor becomes a conscientious dad, something stays the same, the cloth and the man, in these two cases.

In the midst of these obvious changes in marriage, what feature remains the same? What is the essential core that makes marriage distinct from any other relationship? In spite of the variations, spouses have always been male and female. Why? What is unique about this human pairing?

6. “Not all marriages have children.”

Initially it is easy to resist any suggestion that “marriage” and “family” are essentially connected with “offspring.” Clearly, not all families have children. Some marriages are barren, by choice or by design.

This proves nothing, though. Books are written by authors to be read, even if large ones are used as doorstops or discarded ones help ignite campfires. The fact that many lie unread and covered with dust, or piled atop coffee tables for decorative effect doesn’t mean they were not destined for higher purpose.

In the same way, the natural tie of marriage to procreation is not nullified because in some individual cases children are not intended or even possible. Marriage still is what it is even if its essential purpose is never actualized. The exceptions prove the rule, they don’t nullify it. Marriage is intrinsically about and for children.

Ironically, heterosexuals and homosexuals alike confirmed this while lining up to wed at city halls on Valentines Day. “After seven years and the birth of a baby,” the L.A. Times reported, “Robert Manzo and Anna Parker decided to make their union official for 9-month-old Kyle, who they believe should have the legal protection that a marriage gives to a family.”

More than 300 miles away, Kathy Palmer-Lohan stood in line in San Francisco with her partner, Laura, who was seven months pregnant. “We‚re having kids,” Palmer-Lohan said, “and [marriage] gives some formality to the relationship and the family structure.”15

7. “Marriage is a social construction we can redefine as we please.”

What is marriage? There are only two possible kinds of answers to this question: Either marriage and family have a fixed, natural purpose (a natural “teleology”) or they do not. If not, marriage is some kind of social construction, an invention of culture like knickers or bow ties, fashions that change with the times. Marriages defined by convention can be anything culture defines them to be. No particular detail is essential.

It is not possible, however, that marriage is a social construction. Here’s why.

Columnist Dennis Prager has observed, “Every higher civilization has defined marriage as an institution joining members of the opposite sex.” I agree with Prager’s position on marriage, though I take exception with one of his words.

I don't think marriage has been defined by cultures. Rather, I think it has been described by them. The difference in terms is significant. If marriage is defined by culture, then it is merely a construction that culture is free to change when it desires. The definition may have been stable for millennia, yet it is still a convention and therefore subject to alteration. This is, in fact, the argument of those in favor of gay marriage.

The truth is, it is not culture that constructs marriages or the families that marriages begin. Rather, it is the other way around: Marriage and family construct culture. As the building blocks of civilization, families are logically prior to society as the parts are prior to the whole. Bricks aren’t the result of the building because the building is made up of bricks. You must have the first before you can get the second.

Societies are large groups of families. Since families are constituent of culture, cultures cannot define them. They merely observe their parts, as it were, and acknowledge what they have discovered. Society then enacts laws not to create marriage and families according to arbitrary convention, but to protect that which already exists, being essential to the whole.

Why has civilization always characterized families as a union of men and women? Because men and women are the natural source of the children that allow civilized culture to persist. This is the only understanding that makes sense of the definition, structure, legitimacy, identity, and government entitlements of marriage. This alone answers our question, “What is marriage?”

Marriage begins a family. Families are the building blocks of cultures. Families – and therefore marriages – are logically prior to culture.

If the definition of marriage is established by nature, then we have no liberty to redefine it. In fact, marriage itself wouldn’t change at all even if we did. Philosopher Francis Beckwith has wryly observed, “Just because you can eat an ashtray doesn’t make it food.” Linguistic tricks can’t change what nature has already determined something to be. Neither ashtrays nor same-sex marriage provide the nourishment intended by food or families, respectively.

The fact that same-sex couples can legally adopt changes nothing. This, too, subverts the purpose of marriage by robbing families (and children) of a vital ingredient: mothers and fathers. By licensing same-sex marriage, society declares by law that two men or two women are equally suited to raise a child, that mothers and fathers contribute nothing unique to healthy child-rearing. This is self-evidently false. Moms and dads are not interchangeable.

Marriage begins a family. The purpose of family is to produce the next generation. Therefore, family is designed by nature for children. This description alone is consistent with our deepest intuitions, which is why every culture since the birth of time has recognized this. No other characterization fits what societies have been doing for millennia.

Families may fail to produce children, either by choice or by accident, but they are about children, nonetheless. That’s why marriages have always been between men and women; they are the only ones, in the natural state, who have kids.

Government has no interest in affirming any other kind of relationship. It privileges and sustains marriage in order to protect the future of civilization.

Same-sex marriage is radically revisionist. It severs family from its roots, eviscerates marriage of any normative content, and robs children of a mother and a father. This must not happen.

Homosexuality is broadly tolerated in this country. Gays are allowed to pursue their "lifestyles" without reprisal, even to the point of forming committed, monogamous unions. They may not be universally respected or admired, but they have the liberty to live as they choose. This is all they have the right to demand.