Last night my wife and I went to see a panel discussion of homosexuality. There were three scientists there (a Christians psychologist, a secular psychologist who teaches in the psychology dept. and a biologist) and there was a priest and a theologian. In my theology class today we had a discussion about the talk. I suggested to them that people get so angry about this particular subject not because the subject in and of itself is worth getting really angry about (on some level, it's been talked about so much its boring) but because it represents two moral visions of the world. I suggested that there were essentially two visions:
Vision 1: Natural Law (whether Catholic "ordering principles" or Lutheran "orders of creation"): The world was created by God. If we look at anything in the world, we can therefore analyze it on the basis of the question of purpose. So, when I look at a car, just on the basis of how it was built, I can figure out why it was made the way it was- to go places. When I look at human reproductive organs I can do the same thing. The male organ and the female organs work together perfectly- and to a specific end or goal- making babies and all the other things that that entails (i.e. personal intimacy to create a healthy and safe environment, etc.). Bottom line- things are they way they are and function correctly when we use them the way God desired them. Just as a car doesn't work if we try to put oil in the fuel tank, human sexuality doesn't work if we use it in ways that God didn't design.
Vision 2: Autonomy. The highest good is individual autonomy. Any act is justified on the basis of it merely being exercise of human desire. Desire has no purpose or goal. It does not have a design. I should not ask the question "what is the goal of this desire" and "does this fulfill the design that the creator intended?" Rather, the only issue is whether or not it is a free act and whether it is a matter of my exercise of autonomy. Within this system of thought, because highest good is autonomy, one talks about "rights" rather than "obligations" to follow the design of the creator. The only conceivable sin within this system of ethics is interference with the autonomy of the other. Sexuality would then be conceived as being a matter of the autonomous exercise of the fulfillment of desire. If said fulfillment did not hamper the fulfillment of others desires, then there could be nothing wrong it.
I would suggest that vision 2 is problematic not only because it conflicts with the Christian doctrine of creation, but because it is in many ways logically contradictory. First, our desires and the design of our bodies must come from somewhere and have some greater purpose. The idea that our desires are just there and serve no purpose beyond our fulfillment of them doesn't make any sense. We must first be designed and then our desires which are part of our design must have some greater purpose. Otherwise, why would we have them?
Secondly, there's no particular rationale for respecting the rights of autonomy of others within vision 2. Here's why I think most advocates for gay marriage and other thing have strange moral reasoning. First, we're supposed to believe that desire to perform an act is moral self-justifying. This I don't get. Why does the fact that people want to do something make it right? In a wide variety of other acts that people desire are also not right. No advocate of gay marriage will, for example, advocate murder because people want to do it. The next argument that an advocate will likely give is "well, no one is being harmed by it." But this introduces a higher principle than desire into the mix. This means that desire cannot merely exist for itself, but can be discipled and order to a higher goal (i.e. tolerance for the sake harmonious existence).