Gay rights and fertility.

I believe we'd be a better society if gay marriage were allowed because I believe in equal rights for gays. I consider all other arguments about the issue subordinate to that simple principle. No matter how you slice it, without gay marriage, we deny rights to some citizens based on sexual orientation. It's wrong.

With that in mind, I don't feel it's necessary to address the argument given in "Law, Philosophy, and Homosexual 'Marriage'" (because it's irrelevant), but I will anyway.

I keep hearing it said that the rationale for limiting marriage to heterosexuals can't be childrearing, since infertile heterosexual couples are allowed to marry and homosexual couples with children are not.

He goes on to argue that "no gay marriages", as a law, is a sort of heuristic for "only marriages that make children." The reasoning is, legislating what we mean ("only fertile marriages") is too difficult, so the legislature took this short cut. He uses drinking age as another example of a law like this.

Why doesn't the law say, "All and only the mature may drink"? The answer, which should be obvious, is that it would be unworkable. Maturity is difficult (expensive) to ascertain. But we know that maturity is linked to age, even if imperfectly, so we use age as a surrogate for it.

That's an interesting argument, but I consider it bunk for three reasons.

First, age is a good surrogate for fertility too, but we don't restrict the elderly from marrying.

Second, the surrogate law, in the case of drinking age, follows a social custom. People frown upon someone who drinks without being mature enough to handle it. There's nothing similar for infertile marriages. When septuagenarians get married, society does not raise an eyebrow.

Third, this idea directly contradicts existing state law. Illinois state law says:

a marriage between first cousins is not prohibited if: (i) both parties are 50 years of age or older; or (ii) either party, at the time of application for a marriage license, presents for filing with the county clerk of the county in which the marriage is to be solemnized, a certificate signed by a licensed physician stating that the party to the proposed marriage is permanently and irreversibly sterile;

(Emphasis mine.) Right after that it says "a marriage between 2 individuals of the same sex" is prohibited. So, reconcile these statements:

1. Marriage between individuals of the same sex is prohibited because it cannot produce children.
2. Marriage between first cousins is allowed only if it cannot produce children.

I anxiously await a reply.