The essential public purpose of marriage

Link: http://www.mercatornet.com/articles/view/the_essential_public_purpose_of_marriage/

The essential public purpose of marriage is to attach mothers and fathers to their children and to one another.  To see the importance of this purpose, we must take the perspective of the child: What is owed to the child? Unlike adults, the child does not need autonomy or independence. The child is entitled to a relationship with and care from both of the people who brought him into being. Therefore, the child has a legitimate interest in the stability of his parents' union.  But no child can defend these entitlements himself. Nor is it adequate to make restitution after these rights have been violated. The child's rights to care and relationship must be supported pro-actively, before harm is done, for those rights to be protected at all.
Marriage is adult society's institutional structure for protecting the legitimate interests of children. Without this public purpose, we would not need marriage as a distinct social institution.
We often hear the objection that some marriages don't have children. This is perfectly true. However, every child has parents. Depriving a child of relationships with his or her parents is an injustice to the child, and should not be done without some compelling or unavoidable reason. The objection that some marriages don't have children stands the rationale for marriage on its head. It views marriage strictly from the adult's perspective, instead of from the child's perspective.
Same sex couples and opposite sex couples are obviously different with respect to this essential public purpose of marriage.  And treating different things differently is not discrimination. That is why, in the few cases where courts have found opposite sex marriage to be unlawful discrimination, they have had to come up with purposes for  marriage that have nothing to do with procreation or attaching children to parents.

Let us be clear: the alternative to the biological principle for determining parentage is the principle that the government decides who is a parent. Instead of simply recording parentage, the state will determine parentage, not in exceptional cases, but routinely. This is what "getting the state out of the marriage business" will eventually come to mean.
In short, redefining marriage from the union of a man and a woman to the union of any two persons jettisons three foundational principles: first, the principle that children are entitled to a relationship with both parents, second, the biological principle for determining parentage, and third, the principle that the state recognizes parentage, but does not assign it.