by Benjamin L Smith, First Things
[...] For this reason, the promulgation of law can only be justified by grave public necessity. Again, the heterosexual form of marriage passes this test, but there is no grave public necessity meriting the establishment of legally binding homosexual marriage contracts. Homosexual unions, by definition, are intrinsically incapable of producing children. The establishment of gay marriage only advances the private emotional interests of homosexual couples, and private interests do not justify the force of law.
It may be argued that failing to establish homosexual marriage contracts subverts equal protection under the law, but this kind of objection only evinces confusion. Homosexual advocates insist that they must have access to marriage contracts, but this is this already the case. There is no law against homosexual persons contracting heterosexual marriages. The equal protection of the law is only subverted when the same thing is denied to diverse groups only because of their group definition. But heterosexual marriage is not denied to homosexual persons.
This reveals that gay marriage is not the equalizing extension of an already existing contract, but the establishment of a new kind of contract. This pushes the issue back to the question of whether there is a grave and necessary public advantage in promulgating the new institution of gay marriage. The answer must be no.
Finally, it is important to be clear about what I have and have not argued. I have proposed no general theory regarding the nature of marriage or sexuality; nor developed any moral critique of homosexuality or heterosexuality. My argument is based solely on the nature and function of law and the value of self-government. Because law is coercive it may only be promulgated for the sake of grave public necessity. Gay marriage only promotes a private interest and therefore does not justify the force of law.