Marriage is rooted in and arises from the natural complementarity of men and women, and this complementarity is ordered to, even if it does not always issue in, the procreation and rearing of children. Though couples make an intentional choice to marry, marriage is more than an intentional arrangement. Marrying couples enter into an institution that is naturally ordered to certain ends and that naturally provides certain goods. In the words of the Vatican II document Gaudium et Spes,
[B]y that human act whereby spouses mutually bestow and accept each other, a relationship arises which by divine will, and in the eyes of society too, is a lasting one. For the good of the spouses and their offspring as well as of society, the existence of the sacred bond no longer depends on human decisions alone. For God Himself is the author of matrimony, endowed as it is with various benefits and purposes.
Herein lies the principal danger to marriage in this court-imposed legislation. Post-Obergefell, marriage is no longer understood as ordered to the completion and fulfillment of our nature. Rather, it is merely the fulfillment of our desires””for now. And if all marital arrangements are merely intentional acts of will, there is no longer any principled reason to object to anyone’s act of will, desire, or intention if he claims it is sincere: “It’s natural to have desires,” the argument goes, “so whatever you sincerely desire is ‘natural.'” But a marriage entirely of our making is not a marriage at all. In short, Obergefell spells the end of a coherent understanding of marriage.