Many others have written arguments for traditional marriage. In a world in which people only have the patience to listen to 10 words or less, we need to express complex ideas succinctly. So here is a one line argument which I hope might help in expressing the argument for traditional marriage. Why traditional marriage? Here’s why. Heterosexual unions are unique and important.
Firstly, heterosexual marriages are unique. Same sex marriage will never be equal because same sex relationships are different. The heterosexual relationship alone is capable of creating a child. Two men cannot create a child, neither can two women, neither can 1 man alone or 1 woman alone, neither can 1 man and two women, or two women and one man. There is a uniqueness in the combination of 1 man and 1 woman. As much as we don’t want anyone to feel like their relationship is lesser in quality, the hard fact exists that there is at least one respect in which homosexual relationships are inferior- that is, they are biologically incapable of producing offspring. So the heterosexual relationship is unique.
Secondly, the heterosexual union is important. The relationship between male and female with the capacity of producing a child is such an important building block in our society that it is wise for the government to continue to legally validate it and promote its stability through this institution we call marriage.
There are many people in society who passionately love sport. But the government does not legally declare them to be a sport lover. There are many people who love music. But the government sees no reason to declare them a music lover. Of course, it may be inappropriate to compare the love of sport to the romantic sexual love of two humans together. But it prompts the question of why the government should need to legally celebrate any relationship. There are other kinds of sexual love relationships. In some societies a man could have a wife and a mistress- a wife for children and a mistress for sexual pleasure. Both could involve love, but only one is recognised as marriage. A group of 3 or 4 people could all love each other. But this is not marriage (so far at any rate!).
There is something unique about the relationship of one man and one woman, and that uniqueness is important enough for the government to legally recognise and promote it. The reason is that our society’s health and future is built on the foundation of heterosexual relationships who bring children into the world, and this should be celebrated and promoted as the norm of society.
Now, of course, the counter-argument. It is said that children are a red-herring because many gay couples already have children, and studies show gay parents make just as good parents as heterosexual parents. Well, even if you grant the assumption that this is what the studies say (consider this review for example), the issue is not whether gay couples make good parents. Of course they could make good parents. But the fact is, I could be an absolutely lousy parent, and my neighbours could be terrific parents, but of course this doesn’t mean my neighbours have a right to parent my children. I have a permanent biological link to my children which ideally should never be severed. Of course, sometimes a parent’s link with their children is broken. Perhaps the relationship breaks down, and sadly sometimes significant abuse necessitates a separation. Ideally however, children should never be taken away from their parents. There is a biological link which should be normalized, celebrated and promoted.
The same is true for children. A child has a biological link to both of his or her parents which should ideally never be severed. A child should grow up in the care of his or her parents. This is an issue of justice and compassion for them. The problem with same sex marriage is that it is not now just permitting children to be adopted by gay parents. It is now normalizing it and indeed promoting it as completely normal and equivalent. It is stating that there is no difference, and that the union of father, mother and children together is a matter of no difference or priority at all.
Other types of family arrangements will exist of course, but this does not mean we should pretend they are all as ideal as each other. The formation of the core family unit, bonded together by one man and one woman who together conceive and raise their children together is the ideal. This ideal is the reason we legally recognise and promote the institution called marriage in society.