My opposition to gay marriage is three-fold:
1. Marriage is defined currently as the union of one man and one woman. This definition contains two elements: gender and number. If gay activists succeed in removing the gender element of that definition, it will become impossible, as a practical and legal matter, to resist other activists from removing the numerical element. Those who argue that the gender of the partners ought to be eliminated will then find themselves (probably) in the ironic position of having to oppose the efforts of agitators for multiple marriage partners, and in this, they are bound to fail by the force of the very precedent they have set.
2. Marriage is a fundamental institution of our society. We change its definition and its nature only at risk to social consensus. Social consensus is indispensable to social cohesion and cultural identity. That a group which represents approximately eight percent of the population can impose a redefinition of a fundamental social institution on the other ninety-two percent whether they agree or not (and the majority do not agree), is a dangerous prospect. With each of our founding institutions that we allow to erode, we lose more of the cohesiveness and identity we require in order to be a coherent society. To allow a tiny minority to manipulate weak-willed and opportunistic politicians and servile judges to effect such an erosion bodes very ill for our future.
3. Gays have been offered a perfectly acceptable alternative to marriage; namely, civil unions. As I understand it, these offer all the benefits of marriage without violating the accepted social definition of marriage, leaving it intact for the overwhelming majority. As citizens and members of a democratic society, gay people have a civic responsibility to accept such compromise for the sake of social accord. In refusing to do so they risk appearing petulant, selfish and imperious. All of us, in one way or another, make sacrifices of our self-interest for the good of society. We should expect no less of the gay community, and they should extend to society at large the courtesy, and exhibit the maturity, of accepting the offer of compromise.