The following is based on another post that I made on the same thread on Justin Katz’s blog.
I continued responding to another poster's contention that bestiality follows homosexuality. In particular, he wrote:
[I]f a man inserts his member into a rectum for sexual pleasure: 1) if the rectum belongs to a goat, then the act is horrible and should be a crime, but 2) if the rectum belongs to a man, then the act is not a crime, and is instead an act of love so special and profound that we must consider it essentially indistinguishable from the act that produces new human life.
A man’s anus is as related to a male goat’s as a female’s vagina is related to a female goat’s. In other words, we just as logically slide down the slope from “male human anus to goat anus” as we do from “female human vagina to goat vagina.”
Here’s an excellent on point quote from Dr. John Corvino (read the whole article if interested, it deals with ALL of these issues):
The bestiality analogy is the most irksome of the three, since it reveals that the traditionalists are either woefully dishonest or woefully dense. To compare a homosexual encounter — even a so-called “casual” one — with humping a sheep is to ignore the distinctively human capacities that sexual relationships can (and usually do) engage. As such, it is to reduce sex to its purely physical components — precisely the reduction that traditionalists are fond of accusing us of.
I’ve said it before and I’ll say it again, the only thing that ties homosexual sex with polygamy, incest, and bestiality is being frowned on by tradition. Well if that’s our guide, then we also have to logically include interracial couplings as well as heterosexual oral and anal sex, contraception, masturbation, and fornication. I should point out that tradition once justified slavery. There is nothing wrong with sticking with tradition when in doubt—society, therefore doesn’t constantly have to reinvent the wheel. But tradition, in and of itself proves nothing. If tradition can justify a crime against humanity like slavery, then it can justify anything.
Another point demonstrating how logically far apart all of these things are from homosexuality and from one another: Roy Moore—yes that religious nut—is against FMA (good for him—at least we agree on this). One reason that he gave was if marriage is constitutionally defined as one man and one woman, then it could still be a father/daughter, mother/son, brother/sister.
That incest or bestiality can be either homosexual or heterosexual shows that incest by itself is no more logically related to homosexuality than it is to heterosexuality.
When asked to distinguish between interracial couplings and homosexual ones (in terms of being qualified for “marriages,”) a common response would be an interracial couple doesn’t violate the one man one woman definition of marriage—well neither does a brother/sister marriage. Thus, you could just as easily argue, “recognize interracial marriages today, you’ll have incestuous ones tomorrow.” Well what could possibly connect the two? Bingo—both have been frowned upon by traditional values, just like with homosexuality.
So let’s distinguish interracial marriages from incestuous ones. The 14th Amendment clearly prohibits race based classifications; it doesn’t prohibit “family” based classifications as such. Well the 14th Amendment, as currently understood, also prohibits gender based classifications—under a lower, but still heightened basis of scrutiny. And the ban on same-sex marriages clearly is a gender based classification. Numbers (polygamy) and consanguinity (incest) still receive a “rational basis” (the lowest level of scrutiny) review.
And if you are worried about bestial marriages—don’t. Animals do not and never have had the recognized ability to contract with humans. You could no more make a marriage contract with your dog than you could contract with your dog to stop pooping on the kitchen floor.