In order to make a proper argument first we must all understand the roots, history, and intention of marriage. First, marriage is an institution so old that it pre-dates much of written history. Its purposes ranged...
Marriage has been around since before recorded history. One obvious reason for it was the creation of offspring. But a far more important reason for marriage was the cementing of alliances. Difficulties abounded in the ancient world, and the more allies you had the safer you were. Marriages were the preferred method for sealing alliances between families, clans, tribes, and ultimately nations.
Now, while some of these functions have devolved, it is beyond argument that one of the main functions of marriage is to set the model for the stable family unit. Marriage has never merely been creating a union of two people for love, alliances, or even bringing to families together. Marriage and children have been interlocked together for as long as the institution has been around.
In other words, the main function of marriage is to define the stable family unit as one mother, one father, and children. While other functions and uses have come and gone, marriage and children have gone hand in hand since its creation.
Redefining marriage into anything but ONE man and ONE woman will also redefine the best and most stable family unit. The breakdown of the family unit has lead to an explosion of many of the biggest ills we have: higher crime, drug use, and all sorts of other emotional problems. Now more than ever, the stable family unit, one mother, one father and children, must be protected and cherished at all costs.
Thus, the first argument against gay marriage is that it won't simply redefine an institution that goes back before recorded history but it will also redefine the stable family unit. If marriage can be between two men or two women, then so too can the stable family unit be defined as such. Gay couples aren't merely looking for protections afforded married couples. They want their union defined by the term marriage. If it is protection gays are looking for, then I am all for it. I favor states creating non sexual civil unions, though those unions can't be limited to gay couples. Siblings that live together should also be able to protect each other's assets in the case of death for instance. That isn't what gay marriage intends to do. Gay marriage intends to elevate the gay lifestyle on par with the heterosexual lifestyle.
This leads right into the second argument against gay marriage. The gay lifestyle is inherently unequal to the heterosexual one. PC or not, the gay lifestyle doesn't lead to procreation. Without children society dies off. Elevating the gay lifestyle to an equal plane with the heterosexual lifestyle means that procreation is no longer a vital part of society. If you look at the demographic trends of Europe you will see that much of the continent is dying off because most of the continent has stopped procreating. The startling trends in lack of procreation in Europe didn't just happen to coincide with Europe's push toward secularism including legalization of gay marriage in many parts of Europe. In fact, it happened as a result of it. The last twenty years have seen an explosion of secularism in that continent and at the exact same time the continent has seen a significant drop in procreation. The stable family unit is the bedrock of a stable society. If a family unit can be defined by anyone however they want, then chaos ensues and Europe is Exhibit A of that result.
The next argument is the slippery slope argument. This is the one most looked at with condescension by proponents of gay marriage, and yet, not one has answered it to me with satisfaction. In fact, if anyone can satisfy this fear for me, I will become a proponent of gay marriage. If marriage is redefined to include gays, how can anyone tell me that is the end of the redefinition. If the arrangement of the sexes is no longer important, then why is the number or any other part of it important. If I have twelve girlfriends, why can't we all get married. We are all adults and in love, and thus our union should be recognized by marriage just like a gay union. My buddy, his friend, and their two female lovers also want their union defined by marriage. Why is the gay lifestyle included in marriage but the swinger lifestyle is not. The reason this argument is so vital is because once you redefine marriage there are all sorts of unintended consequences. You can't redefine it once and then guarantee that this is the last time it will be redefined. Any argument made for gay marriage can just as easily be made for polygamy, swingers, transvestites, and any other alternative lifestyle that similarly feels aggrieved.
In fact, the most common legal argument made in favor of gay marriage is by invoking the 14th amendment
All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside. No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.
In other words, everyone is treated equally under the law. Thus, if heterosexuals are allowed to marry so should homosexuals. Well, if homosexuals are also allowed to marry, then why shouldn't polygamists, swingers, and transvestites also receive the same "equal protection under the law". The reason that proponents can't answer this is because by their argument they all would. If the 14th amendment means that homosexuals are allowed to marry because of equal protection, then all alternative lifestyles must receive the same equal protection.
In fact, the proponent's condescension and inability to answer this portion of the argument comes down to one simple fact. The gay lifestyle receives a great deal of sympathy from many quarters while all these others are nearly universally seen as freakish and wrong. Not only is that a silly and childish view, because it is the freaks that are most in need of 14th amendment protections.
The next argument is a counter argument. Proponents of gay marriage say that marriage is a right. This is similar to the argument that proponents of socialized medicine make. Anytime anyone wants the government to sanction something the turn it into a "right". Whether it's minimum wage, social security, abortion (through the so called right to privacy) or universal health care, all sorts of so called "rights" have been created by people even though there is no such right in the Constitution. Creating rights out of thin air is dangerous and has all sorts of unintended consequences. This creates bloated government, new laws, and all sorts of new special interest groups and lobbies. The simple fact of the matter is that there is no "right to marry" anywhere in the constitution. If there was, I would have long stopped being single. Thus gay couples have more right to create a marriage out of their relationship than do swingers, polygamists, and transvestites. Marriage pre dates this nation and always it has been defined as one man, one woman, and children.
There is my arguments against gay marriage and I welcome all debate on the matter.