I've been informally debating opponents of legalizing same-sex marriage for nearly 20 years and have a pretty good handle on their most frequently employed arguments. Today I helpfully list them and explain why none passes the test to which we would ordinarily put a prohibition.
1. Same-gender marriage violates tradition.
Yes, most cultures have defined marriage as the union of one man and one woman for hundreds if not thousands of years. But tradition is a mixed bag. It includes slavery and grotesque exploitation of workers, or course, the denial of rights to women and the execution of those who committed thought and property crimes. Traditionally, we treated illnesses with ineffective or dangerous mumbo jumbo, cast aside the disabled and righteously persecuted those with differing religious views.
Integrating a society and expanding human rights has always shattered tradition, and we have consistently been better off for it.
2. Same-gender couples can't produce children.
Marriage is a reflection of the biological necessity of a one-to-one heterosexual union for procreation, true enough, and it provides a legal framework that strengthens that union for the benefit of all. But that's not all marriage is, by any means, which is why the law generally allows prisoners to marry even when they're likely never to be released, has no bar against elderly couples getting married, imposes no fertility requirements on prospective marriage partners and considers long-term childless marriages equal to others.
Further, lesbian couples often get pregnant (with outside help, admittedly, but many heterosexual couples get outside help as well) and their families could benefit as well from the legal framework of marriage.
3. Having a mom and a dad is better for children than having two moms or two dads.
I had an impassioned email argument on just this point last week with an old friend who otherwise supports full equal rights for gays and lesbians.
"My intuitive sense and common sense tells me there are benefits to heterosexual two-parent situations," he wrote (our entire exchange is published online at chicagotribune.com/zorn ). "Legions of people with years of parenting wisdom think there is a difference between two dads or moms, and one of each. The burden of proof is on those who want to set aside the widely accepted norm."
First, no, when it comes to denying a basic right to a class of people, the burden of proof falls on those who rely on intuition and common sense – which, I'm just sayin', happen to be the support pillars of all forms of bigotry – rather than evidence.
Benefits? Harms? Quantify them or stand down.
Making that case won't be easy. Studies show little developmental or social difference between children raised by heterosexual parents and children raised by homosexual parents. In fact on 2010 study in the journal Pediatrics found that children of lesbians scored better in such areas as self esteem, behavior and academic performance than children of straight parents.
Second, even if we concede for the sake of discussion that a stable, loving male-female couple is the gold standard for parenting, it's otherwise offensive to deny those who fall short of the gold standard the right to marry.
For instance, even if data-mining researchers could demonstrate a strong probability that certain pairings would produce suboptimal parents --- couples without high school diplomas, say, or couples with a 30-year gap in their ages or couples with three or more divorces between them -- we would never think of denying such couples marriage licenses.
4. Legalizing same-sex marriage will put us on the slippery slope toward legalizing polygamy.
The practical and philosophical arguments pro and con for multiple-partner marriages (hey, you want to talk about tradition!) are largely distinct from the arguments pro and con about marriage equality. Historians find, for instance, that it destabilizes a society when some men take many wives and leave large numbers of other men without the opportunity to mate.
Same-sex marriage does not fundamentally alter the basic idea of two people agreeing to unite for life and taking on the responsibilities and privileges of that agreement.
Proposals to legalize multiple-partner marriages, should they ever seriously arise in the legislatures and the courts, would be considered separately from laws regarding single-partner marriages, just as the law now considers alcohol separately from crack cocaine, and hasn't slid helplessly down the slope to legalize them both.
5. Same-sex marriage trivializes and therefore weakens the institution of heterosexual marriage.
I almost didn't include this argument on the list because it's faded so dramatically in recent years as country after country, state after state has allowed gays and lesbians to marry with no measurable detriment to straight marriage or conventional families.