"Marriage is linked to reproduction because sex is linked to reproduction.
The logical connection between marriage and children is that every study ever done has shown that having both of their parents around offers many benefits to children. As it turns out, men and women committed to one another and their offspring are what's best for their offspring.
Marriage is based on this logical commitment for the sake of childbearing. As it turns out, healthy people who find suitable mates tend to enjoy not only committing to them, but having kids and committing to their family as well. Who knew."
It is however not necessary for the man and woman to be connected to each other with vows exchanged in marriage for them to remain together, nor does marriage ensure that they will remain together forever. Then again some people marry because they feel the need to do so, simply because they love each other. Love holds priority, children and reproduction being the result of their relationship rather than their marriage.
"Redefining the word "marriage" to mean something that it never has would not bestow social position. Many people would still believe that homosexuality is dysfunctional. Redefining a word won't change minds any more than it will enable homosexuals to procreate.
Unless any ancient people ever used the same word for marriage to describe homosexuals, it's already been well-defined. I do not enjoy these linguistic acrobatics!"
During the ancient Greek, Romanand Egyptian civilisations, where homosexuality was abundant until Christianity became the state religion in the Eastern Roman empire, marriage was normally between man and woman, and the man-on-man contact was done outside of marriage (but still accepted). However, according to quote and source stated below, same-sex marriages were performed in the mesopotamic region.
"A marriage is a union between a man and a woman. It just so happens that such a union is capable of creating children and families. This differs from homosexual unions, which are not marriages capable of creating families. If you have examples of people referring to homosexual relations as marriages in history, I'd love to hear them. Because those relationships just don't serve the same function. They don't have the same status because they're not of the same sort or capacity or purpose."
Here I find that you make a rather strange conclusion. If marriage is intrinsically just simply the union of man and woman, why does the ability to reproduce (by form, as you stress out) have to be a logical consequence of this union? Using the wording "it just so happens" implies that the possibilty to reproduce is just a nifty by product to a union between a man and a woman, and not necessarily to marriage.
For examples of gay marriages/unions in history:
"Ancient evidence survives of kingdom-sanctioned, same-sex cohabitation, as in the tomb drawings of Niankhkhnum and Khnumhotep Evidence exists that same-sex marriages were tolerated in parts of Mesopotamia and ancient Egypt. Artifacts from Egypt, for example, show that same-sex relationships not only existed, but the discovery of a pharaonic tomb for such a couple shows their union was recognized by the kingdom. Meanwhile, accounts of the Israelites' departure for Canaan include their condemnation of Egyptian acceptance of same-sex practice. In actuality, same-sex marital practices and rituals are less known in Egypt compared to Mesopotamia, where documents exist for a variety of marital practices, including male lovers of kings and polyandry. None of the recorded laws of Mesopotamia, including the Code of Hammurabi, contain restrictions against same-sex unions despite the fact that marriages are otherwise well regulated (Eskridge)."
[...]
"Roman social customs are relatively well known, and same-sex unions existed as high in society as among Roman emperors. Roman statesman Cicero also documented legal rights of an individual within a same-sex marriage. Female same-sex unions seemed to have been less common, but only because women enjoyed less freedom in their economic and social endeavors (Eskridge)."
http://www.randomhistory.com/history-of-gay-marriage.html
"Amongst the Romans, there were instances of same-sex marriages being performed, as evidenced by emperors Nero and Elagabalus who married men, and by its outlaw in 342 AD in the Theodosian Code, but the exact intent of the law and its relation to social practice is unclear, as only a few examples of same-sex marriage in that culture exist." ("Emperor Nero is reported to have married at least two men in different occasions.")
http://en.wikipedia.org/wiki/History_of_same-sex_unions
"I'm not sure what you're basing "widely practised" on.
There were plenty of weirdo barbarians back in the day, but that didn't make them the norm."
Plato's Symposium is only one example. Another is the Trojan war, in which Achilles and Ajax (Major?) share a more-than-friendly relationship. In fact, Homerus's Iliad and Odyssey both contain multiple passages referring to homosexual sex. Another example is the duo of Khnumhotep and Niankhkhnum, although some people believe they may have just been brothers and it is based for a large part on speculation.
Other examples:
- King Neferkare of the Middle Kingdom of Egypt and his General Sanset
- Ostraca from the Ramesside Period that depict homosexual sex
Maar doodslaan deed hij niet, want tussen droom en daad,
Staan wetten in de weg en praktische bezwaren,
En ook weemoedigheid, die niemand kan verklaren,
En die des avonds komt, wanneer men slapen gaat.