give same-sex partners the same legal rights as those who are married and in an increasing number of states to register their unions. The remaining issue therefore is the definition of marriage. Changing the law so that marriage includes same-sex unions would be a change to what marriage means. Currently marriage involves a comprehensive union between a man and a woman, and norms of permanence and exclusivity. Marriage has a place in the law because a relationship between a man and a woman is the kind of relationship that may produce children. Marriage is linked to children, for the sake of children, protecting their identity and their nurture by a mother and a father. The State would have no interest in the permanence and exclusivity of marriage if it were not the fact that marriage may produce children. Marriage protects the rights of children There are many variations of households that nurture children, including those that can only have occurred through the use of technology. In all circumstances in which children are nurtured, the State has a parens patriae interest in the welfare of children. It is for that reason that the State is involved with legislating to ensure the identity and status of children. The law determines who are a child's parents in circumstances in which reproductive technology has created ambiguity by separating reproduction from the biological relationship between a man and a woman. In the same way the State has an interest in marriage because the relationship between