New York recently passed a law legalizing same sex marriage, which once again brought the matter into the public eye. Opponents trotted out the stock appeal to tradition fallacy and also made the slightly better argument that passing the law would have dire consequences.
Although I am in favor of legalizing same sex marriage and think that the arguments for it are compelling, as a philosopher I think I am obligated to consider the best possible opposing arguments.
One stock argument is the appeal to tradition: marriage has always/for a long time been between a man and a woman, so same sex marriage should be illegal. As noted above, this line of reasoning is fallacious. The mere fact that X has been around a long time does not make it right. After all, slavery was an accepted practice for a very long time, yet it hardly seems reasonable to accept that it is correct. Also, the “traditional” marriage that people point to is not, in fact, the traditional form of marriage. Marriage as practiced in 21st century western countries is rather different from what was practiced 100 or even 50 years ago, let alone in biblical times.
A second stock argument is the slippery slope argument: if same sex marriage is allowed, then people will then be allowed to marry turtles, dolphins, trees, cats or iPads. Since this would be bad/absurd, same sex marriage should not be allowed. Obviously, this slippery slope is a fallacy since the folks who claim these dire results do not make the causal link needed to infer, for example, that allowing same sex marriage will lead to people marrying goats. Also, a slippery slope argument could be made against allowing same sex marriage: if we allow different sex people to marry, the next thing you know, same sex couples will get married and then people will be marrying flying fish. Since this is absurd, by parity of reasoning the original argument would seem to be absurd as well.
A third stock argument is the religious argument, namely that God forbids same sex activities of this sort. One problem is that if the religious argument is accepted as the basis of law, then the same principle would need to apply across the board. So, for example, there should be laws against unclean foods (like lobster) and it should be legal to stone disobedient children to death. Imposing such religious laws would seem far more harmful than allowing same sex marriage. Another obvious problem is that God is a big boy and He gets what He wants. If he did not want people to be gay, there would presumably be no gay people. In any case, if God does exist, surely He’d pop in and let us know what He thinks about a matter so obviously important to Him. At the very least, He’d throw down a smite or burn a bush.
A fourth stock argument is the procreation argument: marriage is for procreation, same sex couples cannot procreate, therefore they should not be allowed to marry. The stock reply is that straight people who do not or cannot have children are still allowed to marry. Consistency would require that if same sex marriage is banned on these grounds, then straight couples who cannot or will not produce offspring must be denied marriage. This seems absurd.
A fifth stock argument is the moral argument: being gay is evil, evil people should not be allowed t0 marry, so same sex marriage should not be allowed. As with the procreation argument, the obvious flaw is that there are plenty of evil straight people and they are not denied the right to marry on this basis. A person who is a convicted rapist, mass murderer, serial killer, and arsonist can still get married. On a less extreme note, liars, cheats, bullies, and petty thieves can also get married. As such, this argument has little merit.
A sixth catch all argument is the consequence argument: allowing same sex marriage will have dire consequence D, inflicting D is wrong, therefor same sex marriage is wrong. This argument is the strongest of the lot and does have a certain appeal. After all, if same sex marriage were to cause dire harms, then it would seem reasonable to ban it on the same grounds that dangerous things like alcohol and tobacco are banned. I mean, rather on the same grounds that dangerous things like cars and junk food are banned. Um, I mean on the same grounds that heroin and driving drunk are banned.
The main problem with these sorts of arguments lies not with the reasoning or the moral theory (consequentialism). The main problem is that they all seem to suffer from false or dubious premises. Some examples include that it has been claimed that allowing same sex marriage will lead to anarchy, that it will destroy marriage, that it will harm children and so on. However, these claims never seem to stand up to scrutiny. That said, if a harm can be shown and this harm outweighs the benefits of allowing same sex marriage, then it could be argued that it should be banned on the basis of the harm principle. However, the harm has to be properly established and it needs to be the right sort of harm. After all, if some people claim that legalizing same sex marriage will make them very sad, that is not adequate. If it can be shown, for example, that anarchy and chaos will result, then that should suffice.