Argument: Gay marriage should not be banned for tradition
Ted Olson. "The conservative case for gay marriage." Newsweek. January 12, 2010: "The explanation mentioned most often is tradition. But simply because something has always been done a certain way does not mean that it must always remain that way. Otherwise we would still have segregated schools and debtors' prisons."
Wikipedia: Same-sex Marriage: "Proponents of same-sex marriage point out that 'traditional' concepts of marriage in actuality have already undergone significant change. Polygamy has been prohibited, married women are no longer considered the property of their husbands, divorce is legal, contraception within wedlock is allowed, and anti-miscegenation laws forbidding interracial marriage have been eliminated in most modern societies. The fact that changes in the customs and protocols of marriage often occur gives rise to the argument that marriage is dynamic, and same-sex marriage is only the latest evolution of the institution."
"The case for gay marriage". The Economist. February 26th, 2004: "The case for allowing gays to marry begins with equality, pure and simple. Why should one set of loving, consenting adults be denied a right that other such adults have and which, if exercised, will do no damage to anyone else? Not just because they have always lacked that right in the past, for sure: until the late 1960s, in some American states it was illegal for black adults to marry white ones, but precious few would defend that ban now on grounds that it was 'traditional'."
"Let them wed." Economist. January 4th, 1996: "In the end, leaving aside (as secular governments should) objections that may be held by particular religions, the case against homosexual marriage is this: people are unaccustomed to it. It is strange and radical. That is a sound argument for not pushing change along precipitously. Certainly it is an argument for legalising homosexual marriage through consensual politics (as in Denmark), rather than by court order (as may happen in America). But the direction of change is clear. If marriage is to fulfill its aspirations, it must be defined by the commitment of one to another for richer for poorer, in sickness and in health—not by the people it excludes."
Scott Bidstrup. "Gay Marriage: The Arguments and the Motives": "7. Marriage is traditionally a heterosexual institution. This is morally the weakest argument. Slavery was also a traditional institution, based on traditions that went back to the very beginnings of human history. But by the 19th century, humankind had realized the evils of that institution, and has since largely abolished it. Why not recognize the truth -- that there is no moral ground on which to support the tradition of marriage as a strictly heterosexual institution, and remove the restriction?"