It is important to be clear that insistence on the traditional understanding of marriage is not knee-jerk resistance to change but is based on a conviction that the consequences of change will not be beneficial for society as a whole. Our concern is for the way the meaning of marriage will change for everyone, gay or straight, if the proposals are enacted. Because we believe that the inherited understanding of marriage contributes a vast amount to the common good, our defence of that understanding is motivated by a concern for the good of all in society.
The proposition that same-sex relationships can embody crucial social virtues is not in dispute. To that extent, the Prime Minister’s claim that he supports same-sex marriage from conservative principles is readily understandable. However, the uniqueness of marriage is that it embodies the underlying, objective, distinctiveness of men and women. This distinctiveness and complementarity are seen most explicitly in the biological union of man and woman which potentially brings to the relationship the fruitfulness of procreation.