In Part One of this article, we argued that marriage is a union of a man and a woman, committed to sharing their lives together on the bodily, emotional, and rational-volitional levels of their being, in the kind of community that would be naturally fulfilled by having and rearing children together.  Since that kind of multi-leveled community cannot be formed by two persons of the same sex—such persons cannot unite biologically in the way that has always been understood to consummate marriage, and they cannot form the kind of community that would be fulfilled by conceiving, bearing, and raising children together—there cannot in reality be such a thing as same-sex marriage (any more than there can be such a thing as polyamorous marriage—that is, marriage involving three or more partners). Since same-sex (and polyamorous) partners cannot form what are, in truth, marriages, the state’s not granting them marriage licenses is not unjust discrimination.

The argument we advanced for man-woman marriage in Part One of this article is sometimes obscured even by proponents of conjugal marriage. It is sometimes argued that the state’s interest in marriage is simply to ensure that as many children as possible are raised in “an optimal setting,” and that this interest justifies “restricting” marriage to opposite-sex couples. But the fact that intact homes are the optimal setting for child-rearing does not by itself justify a policy of recognizing only opposite-sex partnerships as marriages. For a good end (ensuring optimal care for children) would not justify the means (excluding same-sex “marriage”) if it could be shown that the means were unjust—and denying marriage to such couples, if they were able to form a true marital partnership, would be unjust.

If this argument is advanced as the central one—rather than as a secondary confirmation—then it is misleading. For, in that case, the impression is given that the state itself has created marriage—for the extrinsic purpose of child-rearing. In fact, however, marriage is indeed naturally oriented to and fulfilled by conceiving, bearing, and raising children, but not as to an extrinsic end—and this orientation belongs to marriage independently of any action on the part of the state. In a profound sense, marriage is a “pre-political” institution, albeit one that the law and the state rightly recognize, regulate, promote, and protect.

Moreover, if advanced as the main argument, the “optimal setting” argument locates the center of debate in the wrong place. For even if it could be shown that another type of alliance (for example, two men and a woman, religiously active families, or very wealthy families) would tend to produce better child-rearing outcomes, it would not follow that these alliances were also (or alone) real marriages; and the state’s duty not to confuse true marriage with other arrangements—as we will show—would still obtain. Hence the real ground for the state’s duty to restrict marriage licenses to opposite-sex couples—who are of the age of consent, and have other relevant qualifications—is not an extrinsic goal of marriage, but the actual nature of marriage itself. While the optimal setting argument has a confirming evidential force, advancing it as the central argument diverts attention from how marriage is most centrally related to procreation: marriage is intrinsically (and not merely incidentally or instrumentally) related to procreation.

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The state does have a legitimate interest in promoting and regulating marriage; indeed, it is obligated to do so. The state exists in order to promote ends that (a) serve all within that society, and (b) can effectively and appropriately be pursued by political society (unlike ends that can best be pursued only by individuals, families, or voluntary associations). Such ends constitute the public good, and clearly include defending against external attacks, preserving internal order, facilitating transportation, providing a judicial system for the fair resolution of disputes, etc. But in virtually every political society, the promotion, protection, and regulation of marriage has been understood as part of the public good. This is partly because regulating marriage, and so distinguishing between who is and who is not married, is a task the state cannot escape. For, though marriage is more than a contract, it still is one (it is more, not less, than a contract), and so the state must adjudicate some disputes about marriage, inheritance issues, child custody, and property when spouses separate. For this reason, among many others, privatization of marriage is a practical impossibility. Further, it is abundantly clear that healthy marriages provide social benefits to all.

But the most important reason that the state should protect and promote marriage—including family, which is marriage in its fullest fruition—is that it is itself an irreducible human good, a distinctive and irreplaceable way in which human persons (men, women, and children) can flourish. Hence the strength or weakness of marriage as a social institution profoundly affects the well-being of everyone in a political society.

The state can effectively and appropriately promote marriage. It does so principally by influencing the public understanding of marriage through its laws and regulations. The public understanding and appreciation of marriage—the marriage culture in a given society—greatly influences people’s capacities to participate as fully and richly as possible in this intrinsic human good. Looked at another way, by conveying a gravely distorted view of marriage, the state can weaken and even undermine its members’ capacities for full and rich participation in this important aspect of human flourishing. So, it is not only appropriate but also morally obligatory that the state promote and protect marriage.

But to do so, the state must promote real marriage, not a counterfeit. The state must not obscure the nature of marriage by equating it with other arrangements which differ essentially from marriage. Suppose the state (through its educational curricula) endorsed disinformation and sophistry—counterfeits of the pursuit of knowledge. By doing so, the state would gravely harm the moral environment by which society helps or hinders the moral development and character of its members. The state would send the message that one need not respect the good of truth, that it is normal and acceptable to subordinate one’s reasoning, in disregard for truth, to the attainment of other ends—which, of course, is just what sophistry is. In that way, the state would gravely damage the interests and violate the rights of its citizens. By the same token, by re-defining marriage so as to include same-sex partnerships, the state would convey the message that marriage, instead of being an objective interpersonal union both good in itself and intrinsically linked to procreation, is a relationship principally defined by emotional connection, the exchange of sexual pleasure, and shared housekeeping—all important but nonetheless ancillary features or entailments of genuine marriage. This would undermine the public understanding of marriage and erode respect for the genuine human good of marriage. In a misguided effort to “expand” access to marriage, the state would make it more difficult for people to enter into and live out true marriages. For marriage is the kind of human good that can be chosen and realized only by persons who have some basic understanding of what it essentially is.

What, then, of the argument advanced by Justices Walker, Marshall, and others regarding infertile heterosexual couples? It should by now be obvious how weak this argument is, that it stems from a remarkably simplistic view of how marriage could be related to procreation. The basic argument is: if marriage were intrinsically oriented to procreation, then couples who cannot procreate (the sterile or elderly) could not be married; but they can be married; therefore, etc. No reason is ever given why one should think that the first premise (the if-then proposition) is true. In fact there are numerous reasons why this proposition could be false. And there is only one reason it could be true: namely, if marriage were—either as a community or as an institution—merely instrumental in relation to procreation, a relationship created simply as a means toward an extrinsic goal. But plainly, as we have shown above, it is not. The comprehensive, multi-leveled union of husband and wife is both intrinsically good and the kind of relationship that would be naturally fulfilled by enlarging into family. Since marriage, thus understood, is good-in-itself, and not a mere means, men and women can marry even if they do not, for any number of reasons, have children.

Thus, the familiar argument rehearsed by Justices Walker and Marshall, which asks how the institution of marriage can be primarily about procreation if infertile couples are still eligible to marry, is easily answered. The answer is that the institution of marriage is not primarily about procreation as an end or goal distinct from marriage. The institution is directly about the marital communion itself, which in its fullest fruition is family; and so it is about children, but principally as members of families. True marriage can exist even where children do not come of the union, but it always remains the type of union that would naturally be fulfilled by children, were they to come. And precisely such a relationship has intrinsic value for the men and women who commit to it as spouses and live it out.