I’m not a legal scholar or an expert on the issue of same-sex marriage, but I’d like to offer some thoughts I have had on the subject for some time. Specifically, I want to address the complaint that the traditional restriction of marriage to unions of a man and a woman are discriminatory against gay and lesbian persons.
I would suggest that laws prohibiting two men to marry one another, or two women to marry one another, are not discriminatory at all. They do not even discriminate based on sexual preference or orientation. If you’re homosexual, you can still get married, as long as it is to a person of the opposite gender. To understand why this is not discrimination, consider a far more common sexual orientation and its relevance to the issue of marriage.
A fairly typical male has natural inclinations or proclivities toward sexual relationships with multiple females. That is, he has biological urges that cause him to find women sexually attractive other than his wife. Moreover, this typical male doesn’t seem to be able to eliminate these feelings. They appear to be natural to him. For some reason, he has not yet been added to the alphabet soup of persecuted groups, LGBTQIA, but perhaps he should be. After all, there are a lot of guys in this category, and they get no respect. Admittedly some females have a similar desire to be united sexually with multiple males, and we don’t want to ignore them. Call these people, both males and females, the polyamorous, or the promiscuous, and add them to the mix. Now we have the LGBTQIAP.
At the present time the law allows Ps to pursue sexual relationships with any number of females that they might like as long as they are adults and consent. However, a P cannot be married to more than one woman. He can set up house with each one, if he can afford it, and procreate children by each one, but the fact is that he would not be allowed to marry any of them except one. The law does not allow him to marry anyone else as long as he is already married. Is this “discrimination”? No. The law is not discriminating against promiscuous men. The fact that he may feel that he sincerely “loves” more than one woman does not make the law discriminatory. The P is free to marry; but he is free to marry only one person. The male P is free to marry one person, and that person must be (a) female, (b) not a biological relative within certain parameters, (c) an adult, and (d) consenting to the marriage. So the law is not discriminating against him personally, nor is it discriminating against a class of people (the Ps).
A promiscuous man, then, may marry if he chooses. In doing so he is choosing to renounce his natural inclinations toward multiple sexual partners in the interests of a higher purpose. Billions of Ps have done just that throughout history; thousands of Ps are doing this every week. If a man simply finds refusing his promiscuous inclinations too painful, he is also free not to marry. But it would be ridiculous to claim that marriages with multiple partners needs to be made into a legally sanctioned and protected form of marriage on the grounds that not doing so “discriminates” against the P class of people. At least it seems ridiculous now to most of us. I suspect it already seems sensible to a few of us and that it may seem less ridiculous as our society abandons the traditional understanding of marriage. However sensible or ridiculous one may find such an idea, the fact remains that laws limiting marriages to unions of just two persons are not discriminatory.
Similarly, laws against incest discriminate against no one. Suppose a man and his sister feel that they are in love and want to live together, share property together, have each other in their wills, procreate or adopt children together, etc., etc. Is the law discriminating against them by refusing to recognize their relationship as a marriage? No. Refusing to sanction certain types of unions as marriages is not discrimination. Our law refuses to sanction as marriage sexual unions between an adult and a child, between two consenting adults who are siblings, and between any two individuals if one or both of them are already married to someone else.
Likewise, the lack of legal sanction for same-sex marriages does not constitute discrimination against any individual or class of individuals. No law currently requires anyone to identify his or her sexual orientation prior to getting married. Any consenting adult may marry any other consenting adult within certain limitations: the other adult must not be a close biological relative, must not already be married to someone else, and must be of the opposite gender. The law does not ask how you feel about sex with persons of the same gender or of different gender; it does not ask how many persons you find sexually attractive. It therefore does not discriminate against a class of persons based on their sexual orientation. It does, however, limit the government’s official sanction of marriage in specific ways. One may not like those limitations, or one may argue on some other grounds that they should be eliminated, but they are not discriminatory.
The main objection to the above line of reasoning is that it would mean that prohibiting people of different races to marry one another would not be discriminatory. After all, anti-miscegenation laws, so the objection goes, prohibited no one from getting married, but only prohibited certain kinds of unions, namely, interracial marriages. There are a lot of problems with this objection, not the least of which is that race is an amorphous construct that cannot be defined in a clear enough way to be coherently applicable to marriage laws. It is really not even possible to find an arbitrary standard by which anti-miscegenation laws can be consistently enforced. Those laws, which were on the books in some states in America for two to three centuries, were unjust laws, but not because they “discriminated” against a particular class of people; they applied to ALL people and were nevertheless unjust. Anti-miscegenation laws were irrational on their face: supposedly a single drop of “Negro” blood made a person a Negro, but many drops of “White” blood did not make a person a White. We now know that far more Americans commonly classified as “White” have ancestors of African descent than one could guess by looking at them or even looking at a typical family tree going back a few generations. There is simply no valid comparison between anti-miscegenation laws, which were themselves legal innovations, and the traditional view of marriage as a societally sanctioned union of a man and a woman.
Another problem with this objection is that miscegenationist marriages entail no differences in potential functionality than any other marriages. A black man and a white woman who are married can potentially perform any function normally associated with marriage in the very same way as a white man and a white woman. The claim here is not merely that each and every mixed couple can procreate; it is that a couple, by virtue of its being mixed, is in no way hindered from procreation. By contrast, each and every same-sex couple, simply by virtue of its consisting of two persons of the same gender, is by definition hindered decisively from procreating. Thus a normal function of the marital union is at least possible in most marriages regardless of race or ethnicity but is by definition impossible in any same-sex union.
Also, any heterosexual couple by definition will have one parent of the same gender as any child the couple might procreate or adopt, whereas approximately one-half of all children adopted by same-sex couples (assuming an approximately equal number of gay and lesbian adoptive couples) will necessarily have no parent of the same gender. About half of the adopted boys in such households will be raised with no father. The empirical evidence is overwhelming that the lack of a father will be disadvantageous for boys. This fact cannot be swept aside by citing exceptional circumstances; there are bad heterosexual parents and I would assume by contrast admirable homosexual parents, but overall children do better if they have parents of both genders, and particularly if the boys have fathers. I have nothing but admiration for women who through no fault of their own are doing their best in raising their children without husbands, and I acknowledge that homosexual parents would all things being equal be better than no parents or abusive parents. But these qualifications do not change the fact that same-sex unions, by their very nature, cannot provide the normal dynamic of child-rearing produced in families that have a father and a mother. Obviously, this potential problem does not apply to racially or ethnically mixed marriages, so once again the analogy to anti-miscegenation laws is invalidated.
Having given some reasons why restricting marriages to heterosexual unions is not comparable to anti-miscegenation laws, the argument I presented above stands that shows that disallowing same-sex unions as marriages is not discriminatory. It is more like disallowing incestuous unions as marriages, or disallowing polyamorous associations as marriages. Any consenting adult may marry any other consenting adult, but “marry” here has a specific, recognized, historic meaning, namely, to enter into a publicly-sanctioned, exclusive, perpetual union with a person of the opposite sex. If the couple are siblings, or if their expressed intent is only to enter into a temporary living arrangement, or if the persons forming the union number three or more, or if the union includes two persons of the same sex, then by definition it is not a marriage. It is not arbitrary to define marriage in this way, nor is it discriminatory.
 On the difficulties inherent in defining race, see, for example, C. Loring Brace and George W. Gill, “Does Race Exist?” Nova, 15 Feb. 2000 (presenting opposing viewpoints); Michael J. Bamshad and Steve E. Olson, “Does Race Exist?” Scientific American, 10 Nov. 2003.
 For an interesting article on this subject, see Steve Sailer, “Analysis: White prof finds he’s not,” UPI, 8 May 2002. The article reports that an estimated 30 per cent of “White” Americans have “Black” ancestors.
 See the National Fatherhood Initiative’s webpage on research data on the consequences of father absence, which includes helpful citations. Only some of the data can be explained as the result of only one adult in the household.