Same-sex marriages should be legal in the United States.

I accept Con's definitions, abeit with slight differences which I will expound upon below.Why do we have marriage?Marriage is a social union based upon mutual rights and obligations between the partners. In Western cultures, marriage traditionally was an exclusive and permanent bond between a man and a woman that gives them exclusive sexual rights to each other and establishes parental responsibility for the offspring.In the past, however, marriage was used to create social units in which children could be raised, consolidate wealth, and create kinship between families. The marriages would often be 'arranged' by the parents of the bride or groom, and so was not based on any sort of monogamous love or desire. Men would often take multiple wives due to the advantages in passing their genes down to more offspring (women did not do so because of a psychological stigma attached to it that was a result of males not being certain who the father of a baby was, thus risking investing resources into a baby not carrying his own genes). The creation of marriage as a legal contract came into being gradually as communities settled on the proper organization of a family (the definition of which was enormously fluid from culture to culture and would be based on things such population, resources and food, environment, and preexisting social norms) which was then codified into law. Children could support the family at an early age and so were vital for the financial growth of the family unit. There was little downside to having as many kids as possible (as the wife would raise them), and so creating larger families was the strategy almost all marriages in pre-modern societies followed.The age of political marriage disappeared in the modern age, when producing multiple children were no longer required in order to support a family, removing one of the main motivations of marriage. 'Marriage,' from the point of view of the spouses, became a social bond between the two partners, and having children was only a luxury. While this has weakened marriage somewhat, the underlying reasons for requiring such a lifelong, rigid commitment to be carried out in the first place is still there, as children still need to be raised in stable households and parents still have motivations to do so.So what does this mean for gay marriage?The reason modern states hand out officially mandated marriage licenses to couples are to create the stable environments that children require and giving couples freedom and stability themselves. Anther important purpose of them is organizing society into units that create social order and force the partners to share responsibilities.However, the fundamental difference between this view of marriage and its earlier incarnation is that having children is no longer a central part of it. Creating as many children as possible may have provided an economic boon for earlier families, but it doesn't in an age where children cannot serve any purpose in industry and are merely given mass education to prepare them to take on more sophisticated jobs when they mature (something that would have been unthinkable in antiquity). In modern developed societies infant mortality is effectivey nonexistent, and the population climbs at unnaturally high levels. Couples even have the luxury of adoptng children with different genes and raising them as their own.This undermines the critical purpose at the heart of woman and man marriages. If any two people can fulfill the contractual duties of creating stable family units and caring for children, then having marriage be strictly between a man and a woman is not only unnecessary, but socially counterintuitive as well (for if marriage is about a spiritual or social bond, then homosexuals do these things as well). Therefore homosexual couples should be allowed to recieve marriage licenses, on no other grounds that they can perform the duties and obligations inherent to it just as effectively as a traditional couple would.This is all for now; I await my opponent's critique. Thank you.