On March 26 and 27, the U.S. Supreme Court will hear oral arguments in two cases challenging the definition of marriage as the union of one man and one woman. In Hollingsworth v. Perry, they will consider the constitutionality of the definition as enshrined in the California state constitution by voters in that state when they adopted “Proposition 8” in 2008 (effectively reversing the decision of the California Supreme Court to impose same-sex “marriage” earlier that year). In Windsor v. United States, they will consider the constitutionality of the same definition of marriage being adopted for all purposes under federal law through the 1996 Defense of Marriage Act (DOMA).

In anticipation of those oral arguments, I will here begin a series of blog posts with questions and answers related to the issue.

First, it is important to recognize that while many people describe this as a debate over who has the “right” to marry, it is actually about something much more fundamental—the definition of what “marriage” is.

First, let’s look at what marriage is not.

Isn’t marriage whatever the law says it is?

No. Marriage is not a creation of the law. Marriage is a fundamental human institution that predates the law and the Constitution. At its heart, it is an anthropological and sociological reality, not a legal one. Laws relating to marriage merely recognize and regulate an institution that already exists.

But isn’t marriage just a way of recognizing people who love each other and want to spend their lives together?

If love and companionship were sufficient to define marriage, then there would be no reason to deny “marriage” to unions of a child and an adult, or an adult child and his or her aging parent, or to roommates who have no sexual relationship, or to groups rather than couples. Love and companionship are usually considered necessary for marriage in our culture, but they are not sufficient to define it as an institution.

All right—but if you add a sexual relationship to love and companionship, isn’t that what most people would consider “marriage?”

It’s getting closer but is still not sufficient to define marriage.

In a ruling handed down June 26, 2003, the U. S. Supreme Court declared in Lawrence v. Texas that sodomy laws (and any other laws restricting private sexual conduct between consenting adults) are unconstitutional. Some observers have suggested that this decision paves the way for same-sex “marriage.” But in an ironic way, the Court’s rulings that sex need not be (legally) confined to marriage undermine any argument that sex alone is a defining characteristic of marriage. Something more must be required.