Many of the secular arguments I've seen against legalizing gay marriage resort to questions about allowing incest (polygamy/polyandry doesn't seem to be a big factor in those arguments), arguing that if we allow for same-sex marriages, we have to make an allowance for incest in the name of equality. Others have countered, though, suggesting that from an evidence-based standpoint, incest leads to more congenital birth defects and is overall more harmful to children than same sex marriage is, therefore there is a good reason to discriminate against incest-based relationships while allowing homosexual ones to flourish. 

@GodlessLiberal - Well from some of the folks I've spoken with who make the secular argument against gay marriage, the issue isn't a slippery slope fallacy but one of legal consistency. If two consenting adults choose to get into a marriage, why not let them get married, regardless of their genetic relationship? I don't agree with this conclusion, because I think a balance can be struck between a pure evidence-based pragmatism and legal idealism, but meh, it's worth thinking about. 

@QuantumStorm - Honestly, as much as the concept of incest gives me the willies (and not just because all my cousins are hillbillies with teeth like a British hockey player), I can't discriminate against two consenting adults. Yes, genetic defects are an issue, but the same thing is true of those of African origins, which gives a 25% chance of Sickle Cell Disease. And Eastern European Jews marrying are 100 times more likely to have a genetic disorder like Crohn's Disease and Tay-Sachs.

you got that right!  i just don't understand that such backward way of thinking still exist in this millennia.  by the way, the video is hilarious :)

If having the sort(s) of opinions you have labels me a godless liberal--
then I guess I'm a godless liberal too!

@amateurprose - This is my third time reading it through. It's my favorite of his works, and I've read almost all of them.

I'm reading and liking your conversation with QS. ^_^

@grim_truth - Both of these articles are straining to make this square peg fit into the round hole. And neither mention that by denying homosexuals the same rights that heterosexuals have, you are implying that they are less than equal. Gay teens are five times likelier to commit suicide than their heterosexual classmates. Studies show that these numbers go up when in a conservative environment, and down in a liberal, homosexual-tolerant environment.

This has nothing to do with changing the institution of marriage, which is constantly changing (like when interracial marriage became legal). This has nothing to with infringing on the rights of the majority, since heterosexuals do not suffer one iota from giving homosexual equal rights. None of the articles you provided managed to give a single legitimate secular argument for why gay marriage should be illegal. It simply gave excuses as to why keeping it illegal isn't something we need to worry about. And frankly, they were wrong.

You know what I don't see? Gays and Lesbians having kids. That is a good enough reason for me. Just saying. LOL

@GodlessLiberal - " I said LEGITIMATE arguments."

And what makes an argument ILLEGITMATE? Your personal sensiblities?

"These are secular arguments, but both are idiotic and false."

Nope and irrelevent.

I. Re: Idiotic

Not so.

(1) Scalia is many things but he's not idiotic-- his argument that socities may pass laws on moral sense alone isn't trivially rebutted. At the time of the writing and ratification fo the U.S. Constitution, states and cities have outlawed homosexual acts on nothing but their moral disapproval. If the drafters of the Constitution intended such laws to fall otuside the bounds the Constitution itself, they would have expressed it publicly within the mechanism of the law-making process (or Constitutional Amendments) or have done so in their personal writings.

Just because you dislike a law doesn't mean it's unconstitutional.

(2) If Scalia is wrong, and states & the Federal Government may limit or regulate fundamental rights with a legitmate state interest. Laws dealing with the well-being of the family unit falls well within the purview of the government. If it is the case of gay marriage and the gay family lead to a family unit more harmful or more destructive of that of straight marriages, then government have a legitimate basis for treating gay marriages differently.

II. Re: False

Irrelevent. You asked for arguments-- and whether they withstand scrutiny and the evidence should be played out in debate, not single word dismissals.

@whataboutbahb - Isn't one of the main reasons for Traditional Marriage perpetual regeneration?

@GodlessLiberal - You asked for a legitimate secular argument.  I gave you two, @Celestial_Teapot gave a few more.

You have been given what you asked for, yet dismiss them simply because you don't agree with them.  What is the purpose of claiming "all arguments against homosexual marriage are a based on a book of fiction written 2000 yaers ago" then ignoring the evidence to the contrary?

Quite honestly, this entire post of yours seems to be nothing but an attempt to dismiss the other side by saying "if it's religion behind your opinion, it's not worth as much as mine" but when given secular arguments, you still dismiss them.  Does this make you any better than those who do use religion to base their opinions?  No, it doesn't.