Those seeking to redefine marriage to include same-sex unions often make their case by calling for “equality” in our marriage laws. Claiming that traditional marriage laws are unjust and discriminatory, they seek to right these wrongs and achieve “marriage equality.” However, equality is not a principle that can settle the issue, nor even one that separates the two sides of the marriage debate. Neither advocates of traditional marriage nor revisionists seeking legal recognition for same sex unions are opposed to equality in our marriage laws. The real difference of opinion actually centers on the nature of marriage itself.
Equality under the law does not mean treating everything the same. Rather, it means treating things the same if they actually are the same in relevant and meaningful ways. For example, all individuals deserve equal respect for their human rights. People are all the same with respect to being human, and so they all deserve equal protection of basic human rights like the right to life, free speech, and religious freedom.
Equality certainly does not require that all relationships be recognized as marriages. Many proponents of same-sex marriage would no doubt oppose the recognition of polyamorous relationships (that is, relationships among more than two people), but this does not mean that such people oppose full marriage equality. No one claims that ordinary friendships should be treated as marriages; there is simply no reason they should be. People who form friendships or polyamorous relationships are not somehow given unequal treatment because they cannot legally marry. Current laws simply recognize these relationships for what they truly are: decidedly non-marital.
Despite the rallying cries of some revisionists, laws enshrining traditional marriage do not discriminate in the way that Jim Crow laws against mixed-race marriages did. Those laws had nothing to do with the definition of marriage and instead placed prohibitions on who was eligible for marriage that had no intelligible connection to the actual nature of the union. Proponents of such laws did not believe that members of different races could not physically be wed, but that it was an undesirable threat to a society based on segregation. These laws set up barriers to equality among persons, whereas traditional marriage laws, if their definition of marriage is correct, do not.
Thus the central question of the debate is not “Whom should we allow to marry?” but “What is marriage?” The answer to the latter question can tell us what our marriage laws should be and which relationships ought to be recognized as marriages. It should inform people as to whether marriage ought to be between one man and one woman only, between any two people only, or perhaps even between two or more people.
Defenders of traditional marriage believe that the institution is, and can only be, between one man and one woman. We believe that marriage is by nature comprehensive, uniting spouses in every aspect of the person, including the bodily aspect. Spouses seal their marriage by becoming a single biological principle: that is, by together forming the basic unit that carries out some organic function. This can only be achieved by an act of sexual intercourse that is reproductive in kind (though not necessarily in result). In such acts, spouses quite literally become “one flesh,” like two organs acting in concert for the biological good of the whole. For this reason, marriage must be consummated through intercourse, and only spouses that can possibly perform such acts can truly be married.
It is less clear what most revisionists think about the definition of marriage. Of course, most (though by no means all) want marriage to be a union of any two people, but they generally leave ambiguous the specific characteristics of marriage that lead to this definition. What features of marriage, so conceived, distinguish it from other kinds of relationships? What can consummate it? Why are people only able to enter into it in pairs? These questions are rarely answered in discussions of “marriage equality.”
If revisionists think marriage should be redefined, they must develop an alternative definition for it. They must determine what they think marriage truly is and what its core characteristics are, then present their definition alongside the traditional conception of marriage and argue that theirs is superior. However, mere appeals to equality are insufficient. Equality demands adherence to the true definition of marriage, not unprincipled inclusivity. If there is a case to be made for same-sex marriage, it has little to do with a short slogan.