As I listen to the fallout from President Obama's announcement that he supports marriage equality, I have been struck particularly by the argument that marriage between a man and a woman is superior to committed relationships between same-sex partners.
Official Roman Catholic teaching bases this belief on the theory of natural law, arguing that all sex acts must take place within the state of marriage and must have the potential to create new life. This is why, according to the doctrine, sexual intercourse must always be involved in any sexual activity between a wife and husband.
Since same-sex couples do not have "complementing genders" and, therefore, cannot procreate, their relationships are by their very nature inferior. Having read Aristotle's and Aquinas's theory of natural law, I believe that the church has taken a very rich idea and reduced it to purely the level of biological function.