Argument: Marriage is not reserved solely for those that can reproduce
Andrew Sullivan. "Why 'civil union' isn't marriage." The New Republic. May 8, 2000: "[Many argue] that marriage is primarily about procreation. It is an institution fundamentally designed to provide a stable environment for the rearing of children--and only a man and a woman, as a biological fact, can have their own children within such a marriage. So civil marriage is reserved for heterosexuals for a good, demonstrative reason. The only trouble with this argument is that it ignores the fact that civil marriage is granted automatically to childless couples, sterile couples, couples who marry too late in life to have children, couples who adopt other people's children, and so on. The proportion of marriages that conform to the "ideal"--two people with biological children in the home--has been declining for some time. The picture is further complicated by the fact that an increasing number of gay couples, especially women, also have children. Is there some reason a heterosexual couple without children should have the rights and responsibilities of civil marriage but a lesbian couple with biological children from both mothers should not? Not if procreation is your guide. [...] Indeed, if it is, shouldn't we exclude all childless couples from marriage? That, at least, would be coherent. But how would childless heterosexual couples feel about it? They would feel, perhaps, what gay couples now feel, which is that society is diminishing the importance of their relationships by consigning them to a category that seems inferior to the desired social standard. They would resist and protest. They would hardly be satisfied with a new legal relationship called civil union."