I'm not a fundamentalist libertarian but I do think that individual liberty is a good default. People should generally be able to do what they want and government should start taking away liberties or start treating populations unequally only if there's a very strong reason backed by compelling evidence. And I think that CA Prop 8 was stupid evil. I think it's not just a discriminatory and unnecessary infringement of a minority's civil rights, which is evil, but that it also doesn't even actually accomplish anything. It's like racists trying to limit the spread of leprosy in America by passing a law prohibiting black people from hugging each other. It's not just an apparently mean-spirited persecution of a minority group; it's not even an effective solution to an insignificant problem.
But I'm willing to give the other side a fair shake. Perhaps they know something I don't, and I ought to keep an open enough mind that I will be able to accept their perspective if it is valid. In many ways it would actually please me to discover that there was a rational reason to oppose same-sex marriage, because then I'd be able to stop thinking of Prop 8 opponents as confused or delusional and start thinking of them at least as people with a different solution to a problem that everyone can at least agree exists and needs fixing.
If I'm going to be persuaded that same-sex couples ought to have their civil rights and personal freedoms and liberties limited or that someone else could reasonably believe this, the justification has to fit what I hope we can agree is a reasonable five point rhetorical standard.
A) There must be a significant empirically demonstrable public health or safety issue.
- There must be a significant cost or risk to society or individuals. For example drunk driving, improperly maintained brakes, unsafe buildings. On the other hand many behaviors and choices are only marginally harmful and should not be legally restricted. The natural consequences of choosing unwisely are punishment enough. Casual sex, moderate drinking, the consumption of unsulfured wine or unpasteurized cheese, flying experimental homebuilt aircraft: all OK. Legal recognition of same-sex marriage must rise beyond the level of commonly accepted risks and be more or less equivalent to something else that you and I agree ought also to be forbidden by law. There's a difference between something being legal and something being a good idea.
- The risk must be demonstrable. "You will get lung cancer" is demonstrable. "Your chi will become unfocused" is not. Claims about God are not (as far as I know) unambiguously empirically demonstrable. If your God doesn't want you to do something because it's going to be bad for us, let's talk about the consequences that we can demonstrate will befall us rather than his personal opinion about it.
B) The risk or harm in question must be mitigated by and in proportion to the proposed solution. Symbolic stances and get-tough gestures that don't actually accomplish anything are empty and dumb. Pissing off your enemy is not the same decreasing harm. Middle eastern terrorists might hate you for banning all falafel but it will not decrease the frequency or effectiveness of their attacks
C) No fallacious reasoning:
- No inconsistency or special pleading. Rules must be consistently applied to relevant groups. (Childlessness counts equally for childfree hetero and homo couples.)
- Do not float questionable causes such as confusing correlation and causation or cause and effect. It's possible to demonstrate causality, but you have to show that coincident events are more than coincidence.
- No begging the question or circular reasoning. Don't just restate the point you've not yet demonstrated.
- Stories with evidence we can't examine or corroborate are anecdotes. I have no way of knowing whether the horrible same-sex couple that you know is as horrible as you say, or whether they are representative of all same-sex couples.
- No slippery slopes. If same-sex marriage is fine but other points along the line eventually lead to something bad we should ban the bad thing and leave harmless actions alone.
- No naturalistic fallacies. Space flight, Moon Pies, polyester, or inhaling helium from balloons to make funny voices are without natural precedent. Disasters, parasites, and rape exist throughout the natural world.
D) It ought to go without saying, but reasons must actually be true. You can't just make stuff up.
Here are some examples of reasons which would be disqualified.
"We must protect traditional marriage because it is threatened by gay marriage" fails C (circular reasoning: "we protect TM from threats because SSM is a threat"), C (what 'harm' actually results?), and D (not actually true)
"Homosexuality, by definition, cannot create children" fails A (childfree couples do not significantly harm public health), B (same-sex couples will not be encouraged to have children by banning their marriages), C (inconsistency: some hetero couples are also sterile or childfree), and D (not actually true).
"So-called committed homosexual couples had an average of eight extra-sexual partners per year" fails A (so what?), C (marriage-banned single people will have even fewer reasons to be monogamous), and D (special pleading: should hetero swingers also be forbidden from marrying?)
"Without Prop 8 children will be taught gay marriage in school" fails A (so what?), B (Prop 8 did not effect educational standards), and D (not actually true: previously married SS couples are still married and can still be talked about in schools after parental permission is given)
"We must discourage unhealthy lifestyles" fails B (nobody's going to say "I'll have to take a rain check on that gangbang, looks like I can't get married"), and C (inconsistency: should we also ban marriage for IV drug users?).
"No culture has survived once it ceased to support marriage and monogamy" fails C (correlation is not causation: no culture has survived once it used marble as structural building material), D (lots of cultures currently recognize same-sex marriage and are currently surviving), and B (Prop 8 decreased support for "marriage and monogamy").
"Churches would be forced to recognize and accept same-sex marriages" fails D (not actually true; Prop 8 limited civil marriages, not religious ceremonies. Churches are always free to sanction or condemn anything they want).
To be clear, I'm not saying that the above justifications are automatically invalid. I'm just saying that they're not sufficient as I wrote them but you're welcome to put a finer point on it. You can still say "children will be taught gay marriage in school", but you have to also show how doing so would be a problem and how Prop 8 might stop it.
And also to be clear, these are broad rules that we all should follow, not just in this discussion but in all future discussions about civil liberties or reasonable government action. If I'm arguing in favor of laws banning torture or in favor of enforcement against torturers I have to show that the harm they cause is significant, that the proposed solution will mitigate the problem, etc. You should bookmark these rules and hold me to them if I slip up in the future.